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#151 Re: Jai Ganesh's Puzzles » Doc, Doc! » 2025-08-28 15:15:07
Hi,
#2456. In which part of the human body is Hypopyon associated?
#152 Re: Jai Ganesh's Puzzles » 10 second questions » 2025-08-28 14:42:14
Hi,
#9723.
#153 Re: Jai Ganesh's Puzzles » Oral puzzles » 2025-08-28 14:17:10
Hi,
#6229.
#154 Re: Exercises » Compute the solution: » 2025-08-28 13:55:09
Hi,
2570.
#155 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2025-08-27 22:36:22
2230) Katalin Karikó
Gist:
Work
A vaccine prevents diseases by stimulating the body's immune system to develop a defense against the infectious agent. One type of vaccine uses mRNA, which transfers genetic information from DNA to stimulate protein production. In 2005 Katalin Karikó and Drew Weissman discovered that certain modifications of the building blocks of RNA prevented unwanted inflammatory reactions and increased the production of desired proteins. The discovery laid the foundation for effective mRNA vaccines against COVID-19 during the pandemic that began in early 2020.
Summary
Katalin Karikó (born January 17, 1955, Kisújszállás, Hungary) is a Hungarian-born biochemist known for her pioneering research into RNA (ribonucleic acid) therapeutics, particularly the development of messenger RNA (mRNA) vaccines. Karikó’s investigation into the ability of mRNA nucleosides (structural subunits of nucleic acids) to trigger immune responses against specific pathogens (disease-causing agents) greatly facilitated the development of the first mRNA vaccines—a breakthrough that occurred in 2021, during the coronavirus disease 2019 (COVID-19) pandemic. For their discoveries relating to mRNA nucleosides, which opened the way to the development of effective COVID-19 mRNA vaccines, Karikó and her colleague American immunologist Drew Weissman were awarded the 2023 Nobel Prize in Physiology or Medicine.
Education and early career
Karikó grew up in a small village in Hungary, where from an early age she expressed an interest in nature and excelled academically in science. In 1978, after graduating with a doctoral degree from the University of Szeged, she accepted a position at the Biological Research Centre (BRC), Szeged. There she studied the antiviral activity of short segments of RNA and began her investigations of modified nucleosides, a type of synthetic mRNA in which specific nucleosides have been altered or replaced, typically with either synthetic nucleosides or naturally modified nucleosides.
In 1985, with no further funding to support her research at the BRC, Karikó moved to the United States, where she accepted a position as a postdoctoral researcher at Temple University in Philadelphia. Four years later she took a position at the University of Pennsylvania (Penn). There, with American cardiologist Elliot Barnathan, she demonstrated that mRNA, when inserted into cells, could be used to direct the production of new proteins. The breakthrough inspired her to pursue the study of mRNA-based gene therapy.
By the late 1990s, however, Karikó’s work on mRNA and gene therapy had stalled—again, for lack of funding. She considered leaving Penn for another research institution or pursuing different work entirely, but then she began collaborating at Penn with Weissman. Both researchers were interested in the possibility of using mRNA to stimulate the body to develop immunity against viral pathogens. In initial studies, they discovered that mRNA is highly immunogenic, provoking counterproductive immune responses in the body. However, when Karikó carried out experiments with a different type of RNA molecule, transfer RNA (tRNA), she did not observe the same immunogenic effects. That observation encouraged her and Weissman to experiment with modified nucleosides, which she had known about from her work at the BRC. The researchers went on to identify associations between specific modified mRNA nucleosides and reduced immunogenicity—a breakthrough that resulted in a technology known as non-immunogenic, nucleoside-modified RNA, which was developed and patented (2005) by Karikó and Weissman.
Karikó and Weissman subsequently started a company called RNARx, which aimed to commercialize non-immunogenic, nucleoside-modified RNA. The researchers eventually licensed the technology to two biotechnology companies, Moderna and BioNTech. In 2013 Karikó took a position as senior vice president at BioNTech, overseeing the company’s work on mRNA. In the following years, although both companies had multiple RNA therapeutics in clinical trials, none had yet proved successful. In 2021, however, a major breakthrough came during the COVID-19 pandemic, fueled by the urgency to develop a vaccine that could help prevent or reduce the severity of infection with SARS-CoV-2, the virus that causes COVID-19. Unlike traditional vaccine development, the generation of mRNA vaccines is relatively rapid, relying primarily on synthetic technologies, without any need for actual virus particles. Within months of obtaining the genetic code of SARS-CoV-2, scientists at Moderna and Pfizer-BioNTech had experimental mRNA vaccines ready for testing.
Awards
In addition to the Nobel Prize, Karikó’s work on RNA therapeutics was recognized with numerous honours, including the Lewis S. Rosenstiel Award for Distinguished Work in Basic Medical Research (2020), the Lasker-DeBakey Clinical Medical Research Award (2021), and the Louisa Gross Horwitz Prize (2021); all three awards were shared with Weissman.
Details
Katalin Karikó (born 17 January 1955) is a Hungarian-American biochemist who specializes in ribonucleic acid (RNA)-mediated mechanisms, particularly in vitro-transcribed messenger RNA (mRNA) for protein replacement therapy. Karikó laid the scientific groundwork for mRNA vaccines, overcoming major obstacles and skepticism in the scientific community. Karikó received the Nobel Prize in Physiology or Medicine in 2023 for her work, along with American immunologist Drew Weissman.
Karikó co-founded and was CEO of RNARx from 2006 to 2013. From 2013 to 2022, she was associated with BioNTech RNA Pharmaceuticals, first as a vice president and promoted to senior vice president in 2019. In 2022, she left BioNTech to devote more time to research. In 2021, she received an honorary doctorate from the University of Szeged in Hungary, where she has since become a professor. While Karikó has also been associated with the University of Pennsylvania, which would benefit financially from her eventual discovery, the university had actively discouraged her from pursuing research by underfunding and deprioritizing work on mRNA. After being demoted by the University of Pennsylvania in 1995, Karikó was never granted tenure and joined BioNTech in 2013 after the university had declined to reinstate her.
Karikó's work includes scientific research on RNA-mediated immune activation, resulting in the co-discovery with Drew Weissman of the nucleoside modifications that suppress the immunogenicity of RNA. This is seen as a further contribution to the therapeutic use of mRNA. Together with Weissman, she holds United States patents for the application of non-immunogenic, nucleoside-modified RNA. This technology has been licensed by BioNTech and Moderna to develop their protein replacement technologies, but it was also used for their COVID-19 vaccines.
The messenger RNA-based technology developed by Karikó and the two most effective vaccines based on it, BioNTech/Pfizer and Moderna, have formed the basis for the effective and successful fight against SARS-CoV-2 virus worldwide and have contributed significantly to the containment of the COVID-19 pandemic. For their work, Karikó and Weissman have received numerous other awards besides the Nobel, including the Lasker–DeBakey Clinical Medical Research Award, Time Magazine's Hero of the Year 2021, and the Tang Prize Award in Biopharmaceutical Science in 2022.
#156 Re: Jokes » Lawyer Jokes - V » 2025-08-27 22:11:41
My pleasure!
#157 Re: This is Cool » Miscellany » 2025-08-27 19:19:38
2376) Shinkansen
Gist
The Shinkansen, or "Bullet Train," is Japan's high-speed railway network, known for its speed, reliability, and advanced technology. Opened in 1964 to connect distant regions and facilitate economic growth, the Shinkansen network allows passengers to travel efficiently between major cities like Tokyo, Osaka, and Fukuoka. The trains are characterized by their aerodynamic, bullet-shaped noses and operate on dedicated tracks, with a central management system ensuring high levels of safety.
The Shinkansen, or "Bullet Train," is Japan's high-speed railway network, known for its speed, reliability, and advanced technology. Opened in 1964 to connect distant regions and facilitate economic growth, the Shinkansen network allows passengers to travel efficiently between major cities like Tokyo, Osaka, and Fukuoka. The trains are characterized by their aerodynamic, bullet-shaped noses and operate on dedicated tracks, with a central management system ensuring high levels of safety.
Summary
The Shinkansen, colloquially known in English as the bullet train, is a network of high-speed railway lines in Japan. It was initially built to connect distant Japanese regions with Tokyo, the capital, to aid economic growth and development. Beyond long-distance travel, some sections around the largest metropolitan areas are used as a commuter rail network. It is owned by the Japan Railway Construction, Transport and Technology Agency and operated by five Japan Railways Group companies.
Starting with the Tokaido Shinkansen (515.4 km; 320.3 mi) in 1964, the network has expanded to consist of 2,951.3 km (1,833.9 mi) of lines with maximum speeds of 260–320 km/h (160–200 mph), 283.5 km (176.2 mi) of Mini-shinkansen lines with a maximum speed of 130 km/h (80 mph), and 10.3 km (6.4 mi) of spur lines with Shinkansen services. The network links most major cities on the islands of Honshu and Kyushu, and connects to Hakodate on the northern island of Hokkaido. An extension to Sapporo is under construction and was initially scheduled to open by fiscal year 2030, but in December 2024, it was delayed until the end of FY2038. The maximum operating speed is 320 km/h (200 mph) (on a 387.5 km (241 mi) section of the Tōhoku Shinkansen). Test runs have reached 443 km/h (275 mph) for conventional rail in 1996, and up to a world record 603 km/h (375 mph) for SCMaglev trains in April 2015.
The original Tokaido Shinkansen, connecting Tokyo, Nagoya, and Osaka —three of Japan's largest cities — is one of the world's busiest high-speed rail lines. In the one-year period preceding March 2017, it carried 159 million passengers, and since its opening more than six decades ago, it has transported more than 6.4 billion total passengers. At peak times, the line carries up to 16 trains per hour in each direction with 16 cars each (1,323-seat capacity and occasionally additional standing passengers) with a minimum headway of three minutes between trains.
The Shinkansen network of Japan had the highest annual passenger ridership (a maximum of 353 million in 2007) of any high-speed rail network until 2011, when the Chinese high-speed railway network surpassed it at 370 million passengers annually.
Details
Shinkansen, pioneer high-speed passenger rail system of Japan, with lines on the islands of Honshu, Kyushu, and Hokkaido. It was originally built and operated by the government-owned Japanese National Railways and has been part of the private Japan Railways Group since 1987.
The first section of the original line, a 320-mile (515-km) stretch between Tokyo and Ōsaka, was opened in 1964. Known as the New Tōkaidō Line, it generally follows and is named for the historic and celebrated Tōkaidō (“Eastern Sea Road”) highway that was used especially during the Edo (Tokugawa) period (1603–1867). Inauguration of the line, just before the start of the Tokyo 1964 Olympic Games, was greeted by widespread international acclaim, and the Shinkansen was quickly dubbed the “bullet train” for the great speed the trains obtained and for the aerodynamic bullet shape of their noses. Many innovations, such as the use of prestressed concrete ties and mile-long welded sections of track, were introduced in the line’s construction. A 100-mile (160-km) extension of that line westward from Ōsaka to Okayama was completed in 1972, and its final segment, a 244-mile (393-km) stretch between Okayama and the Hakata station in Fukuoka, northern Kyushu, opened in 1975.
Other lines radiating northward from Tokyo were completed in 1982 to the cities of Niigata (the Jōetsu line) and Morioka (the Tōhoku line), the Tōhoku line subsequently being extended northward to Hachinohe in 2002. Work to build a link to Aomori, northwest of Hachinohe, began in the late 1990s. When that segment opened in 2010, the Shinkansen was essentially complete for the entire length of Honshu. However, plans had long been in place to connect all three main Japanese islands by Shinkansen with a line northward into Hokkaido (via the Seikan Tunnel under Tsugaru Strait). Construction on the Hokkaido line began in 2005 on the segment between Aomori and Hakodate in southern Hokkaido, the ultimate goal being to extend the line to Sapporo. The line between Aomori and Hakodate opened in 2016. Construction on the section from Hakodate to Sapporo was begun in 2012 and expected to be completed in 2031.
Branches from the Tōhoku line to Yamagata opened in 1992 (extended north to Shinjo in 1999) and to Akita in 1997; a branch from the Jōetsu line to Nagano also opened in 1997. Segments of a further extension of the Nagano branch westward to Toyama and Kanazawa opened in 2015. In addition, a line was completed between Yatsushiro and Kagoshima in southwestern Kyushu in 2004. In the late 1990s work commenced to extend that line northward from Yatsushiro to Hakata, and the opening of the segment in 2011 completed the full north-south route of the Shinkansen on Kyushu. Work began in 2008 on a branch from the Kyushu line southwestward to Nagasaki, and it opened in 2022.
Much of the system’s track runs through tunnels, including one under Shimonoseki Strait between Honshu and Kyushu, another on the Tokyo-Niigata line that is 14 miles (23 km) long, and another near Aomori with a record length (for a double-tracked inland tunnel) of 16.5 miles (26.5 km) when the bore was finished in 2005. Several hundred trains operate daily on the Shinkansen system. The most-frequent service is between Tokyo and Ōsaka, especially during the morning and evening rush hours, when trains depart at intervals of 10 minutes or less. The fastest trains can make the trip from Tokyo to Hakata in about five hours, and the quickest from Tokyo to Aomori take about three hours.
The electric multiple-unit trains, which can seat 1,000 passengers or more, derive their power from an overhead wire system. Trains originally reached top speeds of 130 miles (210 km) per hour, but improvements in track, train cars, and other components have made possible maximum speeds of between 150 and 185 miles (240 and 300 km) per hour. In early 2013 some trains began operating at up to 200 miles (320 km) per hour. Such high speeds made it necessary to develop elaborate safety features. Each car, for example, is equipped with brakes consisting of cast-iron discs and metallic pad linings specially designed not to distort under emergency braking. Moreover, all movements of the trains are monitored and controlled by a central computerized facility in Tokyo.
Additional Information
Japan's main islands of Honshu, Kyushu and Hokkaido are served by a network of high speed train lines that connect Tokyo with most of the country's major cities. Japan's high speed trains (bullet trains) are called shinkansen and are operated by Japan Railways (JR).
Running at speeds of up to 320 km/h, the shinkansen is known for punctuality (most trains depart on time to the second), comfort (relatively silent cars with spacious, always forward-facing seats), safety (no fatal accidents in its history) and efficiency. Thanks to various rail passes, the shinkansen can also be a cost-effective means of travel.
Shinkansen network
The shinkansen network consists of multiple lines, among which the Tokaido Shinkansen (Tokyo - Nagoya - Kyoto - Osaka) is the oldest and most popular. All shinkansen lines (except the Akita and Yamagata Shinkansen) run on tracks that are exclusively built for and used by shinkansen trains. Most lines are served by multiple train categories, ranging from the fastest category that stops only at major stations to the slowest category that stops at every station.
#158 This is Cool » Platelets » 2025-08-27 18:29:33
- Jai Ganesh
- Replies: 0
Platelets
Gist
Platelets, or thrombocytes, are small, disc-shaped blood cell fragments produced in the bone marrow that are crucial for blood clotting. When you're injured, platelets adhere to the site of the wound and form a plug to stop or slow bleeding. Conditions like thrombocytopenia (too few platelets) or thrombocytosis (too many) can impair clotting and cause problems with bleeding or the formation of dangerous blood clots, respectively.
Platelets, also known as thrombocytes, are small, colorless cell fragments in the blood that play a crucial role in blood clotting and wound healing. They are not true cells but rather fragments of megakaryocytes, large cells in the bone marrow. When a blood vessel is damaged, platelets help form a blood clot to stop or slow down bleeding.
Summary
Platelets or thrombocytes are a part of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm from megakaryocytes which reside in bone marrow or lung tissue, and then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates (e.g. birds, amphibians), thrombocytes circulate as intact mononuclear cells.
One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site where the lining of vessels (endothelium) has been interrupted. Platelets gather at the site and, unless the interruption is physically too large, they plug it. First, platelets attach to substances outside the interrupted endothelium: adhesion. Second, they change shape, turn on receptors and secrete chemical messengers: activation. Third, they connect to each other through receptor bridges: aggregation. Formation of this platelet plug (primary hemostasis) is associated with activation of the coagulation cascade, with resultant fibrin deposition and linking (secondary hemostasis). These processes may overlap: the spectrum is from a predominantly platelet plug, or "white clot" to a predominantly fibrin, or "red clot" or the more typical mixture. Berridge adds retraction and platelet inhibition as fourth and fifth steps, while others would add a sixth step, wound repair. Platelets participate in both innate and adaptive intravascular immune responses.
In addition to facilitating the clotting process, platelets contain cytokines and growth factors which can promote wound healing and regeneration of damaged tissues.
Details
Platelets are cell fragments and the smallest component of your blood. Their primary job is to stop the bleeding if you’re injured. If a blood vessel is damaged, platelets cluster together to form a plug first and then a clot to stop the blood loss. Common conditions involving platelets include thrombocytopenia and thrombocytosis.
What are platelets?
Platelets, also called thrombocytes, are tiny cell fragments in your blood that help with clotting. Platelets are your body’s natural bandage to stop bleeding if you’re injured.
Just a single drop of your blood contains tens of thousands of platelets. It’s important that you have enough (but not too many) of them. Too few platelets can put you at risk of losing too much blood if you’re injured. Too many platelets may increase your risk of dangerous blood clots. The right number of platelets can prevent blood loss during injury without putting you at risk of harmful clots that can restrict blood flow.
Function:
What do platelets do?
Your platelets’ primary function is to stop bleeding if a blood vessel gets damaged. During an injury, platelets cluster together at the site of the wound to act as a plug. They also help seal the blood vessels in a process called clotting (coagulation) to prevent excess blood from leaving your body.
The official process to stop bleeding from a damaged blood vessel is called hemostasis. Here’s a breakdown of how platelets function during hemostasis:
* Adhesion: The platelets that circulate in your blood travel to the break in the blood vessel wall and stick (“adhere”) there.
* Activation: The platelets that stick to the wall go through changes that keep hemostasis going. For example, they release substances that cause the blood vessel to narrow so less blood seeps out. They also release substances to attract more platelets to the wound site. They change shape so that it’s easier for the new platelets to bind together.
* Aggregation: The platelets stick together to form a temporary plug that seals the break in the blood vessel wall.
The action of the platelets triggers a series of events called the “coagulation cascade.” During this process, proteins called clotting factors work together to create a substance called fibrin. The fibrin acts as a powerful mesh that reinforces the platelet plug. Together, these elements form a more stable blood clot that stops the bleeding.
Anatomy:
Where are platelets located?
Your platelets are located primarily in your bone marrow, blood and spleen.
* Bone marrow: Platelets form from the largest cells in your bone marrow — white blood cells called megakaryocytes. New platelets bud from the megakaryocytes. This is why platelets are considered cell fragments instead of whole cells.
* Blood: Whole blood consists of plasma (the liquid part), red blood cells, white blood cells and platelets. As platelets are the lightest component of whole blood, they are pushed to the walls of your blood vessels, allowing plasma and blood cells to flow through the center. The location helps platelets reach injured blood vessel walls quickly to stop bleeding.
* Spleen: Your spleen stores about one-third of your platelets. It also filters old or damaged platelets.
How many platelets are in my blood?
Platelets and white blood cells make up 1% of your whole blood, along with plasma (55% total volume) and red blood cells (44% total volume). There’s about 1 platelet for every 20 red blood cells in your body.
At any given time, a healthy person has 150,000 to 450,000 platelets per microliter of blood. Your body is continually making platelets because they only live for about seven to 10 days. It takes about 72 hours (three days) for your body to make new platelets.
What do platelets look like?
Platelets are small, colorless cell fragments. They form in the shape of a plate, which is where they get their name. Proteins on the exterior of your platelet walls are sticky to help them adhere to your blood vessels. When actively clotting, platelets extend filaments (a long thread of cells) that resemble legs on a spider. These legs make contact with the broken blood vessel and other platelets to seal the damage and stop the bleeding.
Conditions and Disorders:
What are the common conditions and disorders that affect platelets?
Most platelet conditions involve having too few or too many platelets:
* Thrombocytopenia (low platelet count): Conditions that prevent your body from making platelets or that destroy them prematurely can cause low platelets. Low platelets increase your bleeding risk.
* Thrombocytosis (high platelet count): Conditions that cause high platelets involve primary problems with platelet production in your bone marrow or secondary problems, where platelets increase in response to something else.
What are common signs or symptoms of a condition affecting my platelets?
Common signs and symptoms of platelet conditions include:
* Bruising (including purpura and petechiae).
* Frequent nosebleeds (epistaxis) or bleeding gums in your mouth.
* Blood in your poop or pee.
* Internal bleeding.
*Excessive bleeding from small wounds.
* Heavy menstrual bleeding (menorrhagia).
* An enlarged spleen (splenomegaly).
* Muscle and joint pain.
* Tingling in hands/feet (paresthesia).
* Leg swelling (edema).
* Severe headaches, weakness or dizziness.
What tests check the health of my platelets?
Tests that check the health of your platelets include:
* Complete blood count (CBC): This blood test identifies how many blood cells and platelets are circulating throughout your body. A platelet count is the specific part of a CBC that checks how many platelets you have.
* Peripheral blood smear (PBS): During this test, a provider looks at a sample of blood beneath a microscope to check for abnormal blood cells and platelets. Oddly shaped or giant platelets may be signs of a condition.
* Blood clotting tests: A prothrombin time test and a partial thromboplastin time test check for multiple factors related to how your blood clots.
* Bone marrow biopsy: Your healthcare provider removes a sample of your bone marrow to examine the health of your cells where platelets form.
* Genetic tests: These tests can show if you have a genetic mutation (a change) that’s causing issues with how your platelets function.
What are common treatments for platelet-related conditions?
Treatments for platelet conditions include:
* Over-the-counter medications: Taking a low dose of aspirin daily can prevent harmful blood clots if you’re at risk.
* Prescription medications: Some medications slow the production of platelets in your bone marrow. Others treat the condition causing abnormal platelets, like autoimmune diseases or infections.
* Plateletpheresis: This procedure is a type of apheresis that treats high platelets. It uses a machine to filter out some of the excess platelets.
* Platelet transfusions: You may need a special type of blood transfusion that involves receiving blood with high concentrations of platelets if you’re at risk of severe blood loss because of low platelets.
* Surgery to remove your spleen (splenectomy): You may need this surgery if your spleen is trapping too many platelets and causing low counts.
Care:
How do I keep my platelets healthy?
It’s important to follow your healthcare provider’s instructions if you have a condition that’s causing problems with your platelets. Even if you don’t have a condition, you can care for your platelets by:
* Limiting your alcohol intake.
* Not smoking.
* Avoiding toxic chemicals.
* Taking care to avoid injury.
You can also help care for others by donating platelets. The process is similar to donating blood, except it involves removing some of your platelets and returning the other blood components back to you. Platelet donations help individuals with chronic illnesses, cancer or serious injuries.
Additional Information
A is a platelet, colourless, nonnucleated blood component that is important in the formation of blood clots (coagulation). Platelets are found only in the blood of mammals.
Platelets are formed when cytoplasmic fragments of megakaryocytes, which are very large cells in the bone marrow, pinch off into the circulation as they age. They are stored in the spleen. Some evidence suggests platelets may also be produced or stored in the lungs, where megakaryocytes are frequently found.
Platelets play an important role in the formation of a blood clot by aggregating to block a cut blood vessel and provide a surface on which strands of fibrin form an organized clot, by contracting to pull the fibrin strands together to make the clot firm and permanent, and, perhaps most important, by providing or mediating a series of clotting factors necessary to the formation of the clot. Platelets also store and transport several chemicals, including serotonin, epinephrine, histamine, and thromboxane; upon activation these molecules are released and initiate local blood vessel constriction, which facilitates clot formation.
At birth the number of platelets is low, but by three months of age the adult level is reached. The number of platelets rises following trauma or asphyxiation, at high altitudes, after exercise, and in cold temperatures; the number may be temporarily lowered by menstruation in women. Certain chemicals may prolong the life of platelets; smoking is believed to shorten their life spans.
#159 Dark Discussions at Cafe Infinity » Climb Quotes - III » 2025-08-27 17:47:46
- Jai Ganesh
- Replies: 0
Climb Quotes - III
1. Like dogs in a wheel, birds in a cage, or squirrels in a chain, ambitious men still climb and climb, with great labor, and incessant anxiety, but never reach the top. - Robert Browning
2. The tree I had in the garden as a child, my beech tree, I used to climb up there and spend hours. I took my homework up there, my books, I went up there if I was sad, and it just felt very good to be up there among the green leaves and the birds and the sky. - Jane Goodall
3. Climb the mountains and get their good tidings. - John Muir
4. If I know I make this much trouble, I never climb Everest. - Tenzing Norgay
5. If you're trying to achieve, there will be roadblocks. I've had them; everybody has had them. But obstacles don't have to stop you. If you run into a wall, don't turn around and give up. Figure out how to climb it, go through it, or work around it. - Michael Jordan
6. The soul grows by reincarnation in bodies provided by nature, more complex, more powerful, as the soul unfolds greater and greater faculties. And so the soul climbs upward into the light eternal. And there is no fear for any child of man, for inevitably he climbs towards God. - Annie Besant
7. I think I mainly climb mountains because I get a great deal of enjoyment out of it. I never attempt to analyze these things too thoroughly, but I think that all mountaineers do get a great deal of satisfaction out of overcoming some challenge which they think is very difficult for them, or which perhaps may be a little dangerous. - Edmund Hillary
8. He climbs highest who helps another up. - Zig Ziglar.
#160 Re: Maths Is Fun - Suggestions and Comments » Credible place to find help and infromation » 2025-08-27 17:28:33
I am a Physics graduate. I have experience of 35 years plus before browsing the net, 25 on the net roughly. I concede Rod and Bob much more experience. I verify facts before posting, as a rule.
#161 Science HQ » Thulium » 2025-08-27 17:14:38
- Jai Ganesh
- Replies: 0
Thulium
Gist
Thulium (Tm) is a silvery-gray, soft, rare-earth metal belonging to the lanthanide series, with the atomic number 69. It's named after Thule, an ancient name for Scandinavia. While it's the second-least abundant lanthanide, its unique properties make it valuable for high-tech applications, including medical lasers and portable X-ray units, and it is used in ceramic magnetic materials for microwaves.
Thulium is used in portable X-ray devices as a radiation source, in the production of solid-state lasers for surgical applications, and in ceramic magnetic materials (ferrites) for microwave equipment. It is also used in personal dosimeters for radiation monitoring due to its fluorescent properties.
Summary
Thulium is a chemical element; it has symbol Tm and atomic number 69. It is the thirteenth element in the lanthanide series of metals. It is the second-least abundant lanthanide in the Earth's crust, after radioactively unstable promethium. It is an easily workable metal with a bright silvery-gray luster. It is fairly soft and slowly tarnishes in air. Despite its high price and rarity, thulium is used as a dopant in solid-state lasers, and as the radiation source in some portable X-ray devices. It has no significant biological role and is not particularly toxic.
In 1879, the Swedish chemist Per Teodor Cleve separated two previously unknown components, which he called holmia and thulia, from the rare-earth mineral erbia; these were the oxides of holmium and thulium, respectively. His example of thulium oxide contained impurities of ytterbium oxide. A relatively pure sample of thulium oxide was first obtained in 1911. The metal itself was first obtained in 1936 by Wilhelm Klemm and Heinrich Bommer.
Like the other lanthanides, its most common oxidation state is +3, seen in its oxide, halides and other compounds. In aqueous solution, like compounds of other late lanthanides, soluble thulium compounds form coordination complexes with nine water molecules.
Details
Thulium (Tm) is a chemical element, a rare-earth metal of the lanthanide series of the periodic table.
Thulium is a moderately hard, silvery white metal that is stable in air but can easily be dissolved in diluted acids—except hydrofluoric acid (HF), in which an insoluble trifluoride (TmF3) layer forms on the surface of the metal, impeding further chemical reaction. Thulium is a strong paramagnet above 56 K (−217 °C, or −359 °F). Between 56 and 32 K (−241 °C, or −402 °F) the metal is antiferromagnetic with a sinusoidally modulated magnetic structure along the c-axis of its crystal structure, and below 32 K thulium is ferrimagnetic.
Thulium was discovered in 1879, along with holmium, by Per Teodor Cleve, who named the oxide thulia after an ancient name for Scandinavia. It is found in small amounts in such rare-earth minerals as laterite ionic clays, xenotime, and euxenite and in products of nuclear fission. Thulium is one of the rarest of the rare-earth elements. Its abundance in Earth’s crust is nearly the same as those of antimony and iodine.
Natural thulium is wholly composed of the stable isotope thulium-169. Thirty-five radioactive isotopes (excluding nuclear isomers) are known. They range in mass from 144 to 179, and their half-lives range from more than 300 nanoseconds (thulium-178) to 1.92 years (thulium-171). Bombarded by neutrons, natural thulium becomes radioactive thulium-170 (128.6-day half-life), which ejects soft gamma radiation with wavelength commensurate with laboratory hard X-ray sources. Only one allotropic (structural) form is known for thulium. The element adopts a close-packed hexagonal structure with a = 3.5375 Å and c = 5.5540 Å at room temperature.
Commercial production involves solvent-solvent extraction or ion exchange from monazite. The metal is prepared by reduction of its oxide by lanthanum metal followed by distillation of the thulium metal. Thulium has little practical use beyond research. Thulium-170 is used in small portable X-ray sources suitable for medical X-ray imaging and nondestructive evaluation of thin-walled structures. Together with yttrium, thulium is a component of some high-temperature superconducting oxides. The element is also employed as a dopant in yttrium-aluminum garnet for laser applications.
Thulium can be prepared in the +2 oxidation state, as in the dark-coloured diiodide TmI2. The Tm2+ ion is not stable in water; it momentarily gives a violet-red colour before being oxidized to the predominant +3 state. Thulium in the stable +3 state forms a series of pale green salts.
Element Properties
atomic number : 69
atomic weight : 168.93421
melting point : 1,545 °C (2,813 °F)
boiling point : 1,950 °C (3,542 °F)
specific gravity : 9.321 (at 24 °C, or 75 °F)
oxidation states : +2 (unstable), +3 (stable).
Additional Information:
Appearance
A bright, silvery metal.
Uses
When irradiated in a nuclear reactor, thulium produces an isotope that emits x-rays. A ‘button’ of this isotope is used to make a lightweight, portable x-ray machine for medical use. Thulium is used in lasers with surgical applications.
Biological role
Thulium has no known biological role. It is non-toxic.
Natural abundance
Thulium is found principally in the mineral monazite, which contains about 20 parts per million. It is extracted by ion exchange and solvent extraction. The metal is obtained by reducing the anhydrous fluoride with calcium, or reducing the oxide with lanthanum.
#162 Re: Jai Ganesh's Puzzles » General Quiz » 2025-08-27 16:46:44
Hi,
#10537. What does the term in Biology Cell plate mean?
#10538. What does the term in Biology Cell theory mean?
#163 Re: Dark Discussions at Cafe Infinity » Why, different levels of intelligence. » 2025-08-27 16:30:59
Individuals differ from one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, to overcome obstacles by taking thought. Although these individual differences can be substantial, they are never entirely consistent: a given person's intellectual performance will vary on different occasions, in different domains, as judged by different criteria. Concepts of "intelligence" are attempts to clarify and organize this complex set of phenomena. Although considerable clarity has been achieved in some areas, no such conceptualization has yet answered all the important questions, and none commands universal assent. Indeed, when two dozen prominent theorists were recently asked to define intelligence, they gave two dozen, somewhat different, definitions.
Human
Human intelligence is the intellectual power of humans, which is marked by complex cognitive feats and high levels of motivation and self-awareness. Intelligence enables humans to remember descriptions of things and use those descriptions in future behaviors. It gives humans the cognitive abilities to learn, form concepts, understand, and reason, including the capacities to recognize patterns, innovate, plan, solve problems, and employ language to communicate. These cognitive abilities can be organized into frameworks like fluid vs. crystallized and the Unified Cattell-Horn-Carroll model, which contains abilities like fluid reasoning, perceptual speed, verbal abilities, and others.
Intelligence is different from learning. Learning refers to the act of retaining facts and information or abilities and being able to recall them for future use. Intelligence, on the other hand, is the cognitive ability of someone to perform these and other processes.
Intelligence quotient (IQ)
There have been various attempts to quantify intelligence via psychometric testing. Prominent among these are the various Intelligence Quotient (IQ) tests, which were first developed in the early 20th century to screen children for intellectual disability. Over time, IQ tests became more pervasive, being used to screen immigrants, military recruits, and job applicants. As the tests became more popular, belief that IQ tests measure a fundamental and unchanging attribute that all humans possess became widespread.
An influential theory that promoted the idea that IQ measures a fundamental quality possessed by every person is the theory of General Intelligence, or g factor. The g factor is a construct that summarizes the correlations observed between an individual's scores on a range of cognitive tests.
Today, most psychologists agree that IQ measures at least some aspects of human intelligence, particularly the ability to thrive in an academic context. However, many psychologists question the validity of IQ tests as a measure of intelligence as a whole.
#164 Re: Jai Ganesh's Puzzles » English language puzzles » 2025-08-27 16:13:07
Hi,
#5727. What does the noun linac mean?
#5728. What does the noun lilt mean?
#165 Re: Jai Ganesh's Puzzles » Doc, Doc! » 2025-08-27 15:41:11
Hi,
#2455. What does the medical term Growth factor signigy?
#166 Re: Jai Ganesh's Puzzles » 10 second questions » 2025-08-27 15:06:45
Hi,
#9723.
#167 Re: Jai Ganesh's Puzzles » Oral puzzles » 2025-08-27 14:27:41
Hi,
#6228.
#168 Re: Maths Is Fun - Suggestions and Comments » Confused » 2025-08-27 14:12:57
No more posts on this thread. It isn't going anywhere.
#169 Jokes » Lawyer Jokes - VII » 2025-08-27 14:06:52
- Jai Ganesh
- Replies: 0
Q: What do lawyers do after they die?
A: They lie still.
* * *
Q: When attorneys die, why do they bury them 600 feet underground?
A: Because deep down, they're really nice guys.
* **
Q: What's the difference between a lawyer and a trampoline?
A: You take off your shoes before you jump on a trampoline.
* * *
Q: What do you get if you put 100 lawyers in your basement?
A: A whine cellar.
* * *
Q: What do you call a lawyer gone bad?
A: Your honor.
* * *
#170 Re: Exercises » Compute the solution: » 2025-08-27 13:50:39
Hi,
2569.
#171 Re: Maths Is Fun - Suggestions and Comments » Confused » 2025-08-26 23:08:11
Zach Alie,
You are free to post. I am not preventing. Just remember, don't post indiscriminately. I have a duty as an Administrator.
#172 Re: This is Cool » Behind the scenes of proof by contradiction II » 2025-08-26 23:02:38
Hi Ivar Sand,
I was experimenting.
#173 Dark Discussions at Cafe Infinity » Climb Quotes - II » 2025-08-26 22:43:35
- Jai Ganesh
- Replies: 0
Climb Quotes - II
1. If you don't have a mountain, build one and then climb it. And after you climb it, build another one; otherwise you start to flatline in your life.- Sylvester Stallone
2. He that climbs the tall tree has won right to the fruit, He that leaps the wide gulf should prevail in his suit. - Walter Scott
3. Sometimes, there's a fine line between bravery and utter stupidity. The day I decided to climb into a boxing ring for a professional fight was probably on the side of stupidity. - Andrew Flintoff
4. Despite all I have seen and experienced, I still get the same simple thrill out of glimpsing a tiny patch of snow in a high mountain gully and feel the same urge to climb towards it. - Edmund Hillary
5. Man can climb to the highest summits, but he cannot dwell there long. - George Bernard Shaw
6. With ideas it is like with dizzy heights you climb: At first they cause you discomfort and you are anxious to get down, distrustful of your own powers; but soon the remoteness of the turmoil of life and the inspiring influence of the altitude calm your blood; your step gets firm and sure and you begin to look - for dizzier heights. - Nikola Tesla
7. For a traveler going from any place toward the north, that pole of the daily rotation gradually climbs higher, while the opposite pole drops down an equal amount. - Nicolaus Copernicus
8. There are some cases in which the sense of injury breeds not the will to inflict injuries and climb over them as a ladder, but a hatred of all injury. - George Eliot.
#174 Re: This is Cool » Miscellany » 2025-08-26 22:19:30
2375) Strait
Gist
A strait is a narrow body of water that connects two larger bodies of water and separates two landmasses. It serves as a natural waterway, often crucial for navigation and shipping. For example, the Strait of Gibraltar connects the Atlantic Ocean and the Mediterranean Sea.
Summary
A strait is a narrow channel of water between two land areas. A strait connects two bodies of water. Straits often connect two seas. Many straits are economically and strategically important. Straits may be part of important shipping routes. So, someone who controls a strait can control the shipping. Wars have been fought to control them. Although rivers and canals often connect two large lakes or a lake and a sea, they are not straits. Straits are much larger and wider and do not have water running in a single direction.
Well-known straits
Well-known straits in the world are:
* Bosporus and the Dardanelles, which connect the Mediterranean and the Black Sea
* Strait of Dover, between England and France, which connects the North Sea with the English Channel
* Strait of Gibraltar, the only natural passage between the World Ocean and the Mediterranean Sea
* Bering Strait between Alaska and Siberia, which connects the Pacific and Arctic Oceans
* Strait of Magellan, connecting the Atlantic and Pacific Oceans north of Tierra del Fuego
* Palk strait, between India and Sri Lanka, the location of Ram Sethu and rich in natural resources
* Strait of Hormuz connecting the Persian Gulf and the Oman Sea, through which Persian Gulf petroleum is shipped to the world
* Strait of Malacca, which separates the Malay Peninsula from Sumatra, and connects the Indian Ocean with the South China Sea. (It is one of the highest-volume shipping lanes in the world.)
* Bass Strait, which is between mainland Australia and Tasmania, and connects the Indian Ocean with the Pacific Ocean.
* Torres Strait which is between Australia and New Guinea.
* Cook Strait, between New Zealand's North and South Islands, and connects the Tasman Sea and the South Pacific Ocean.
Details
A strait is a water body connecting two seas or water basins. The surface water is, for the most part, at the same elevation on both sides and can flow through the strait in either direction, although the topography generally constricts the flow somewhat. In some straits, there is a dominant directional current. Most commonly, the strait is a narrow channel that lies between two land masses. Straits are loci for sediment accumulation, with sand-sized deposits usually occurring on the two strait exits, forming subaqueous fans or deltas. Some straits are not navigable because, for example, they are too narrow or too shallow, or due to the presence of a reef or archipelago.
Terminology
The terms channel, pass, or passage can be synonymous and used interchangeably with strait, although each is sometimes differentiated with varying senses. In Scotland, firth or Kyle are also sometimes used as synonyms for strait.
Many straits are economically important. Straits can be important shipping routes and wars have been fought for control of them.
Numerous artificial channels, called canals, have been constructed to connect two oceans or seas over land, such as the Suez Canal. Although rivers and canals often provide passage between two large lakes, and these seem to suit the formal definition of strait, they are not usually referred to as such. Rivers and often canals, generally have a directional flow tied to changes in elevation, whereas straits often are free flowing in either direction or switch direction, maintaining the same elevation. The term strait is typically reserved for much larger, wider features of the marine environment. There are exceptions, with straits being called canals; Pearse Canal, for example.
Comparisons
Straits are the converse of isthmuses. That is, while a strait lies between two land masses and connects two large areas of ocean, an isthmus lies between two areas of ocean and connects two large land masses.
Some straits have the potential to generate significant tidal power using tidal stream turbines. Tides are more predictable than wave power or wind power. The Pentland Firth (a strait) may be capable of generating 10 GW. Cook Strait in New Zealand may be capable of generating 5.6 GW even though the total energy available in the flow is 15 GW.
Navigational (legal) regime
Straits used for international navigation through the territorial sea between one part of the high seas or an exclusive economic zone and another part of the high seas or an exclusive economic zone are subject to the legal regime of transit passage (Strait of Gibraltar, Strait of Dover, Strait of Hormuz). The regime of innocent passage applies in straits used for international navigation (1) that connect a part of high seas or an exclusive economic zone with the territorial sea of a coastal nation (Straits of Tiran, Strait of Juan de Fuca, Strait of Baltiysk) and (2) in straits formed by an island of a state bordering the strait and its mainland if there exists seaward of the island a route through the high seas or through an exclusive economic zone of similar convenience with respect to navigational and hydrographical characteristics (Strait of Messina, Pentland Firth). There may be no suspension of innocent passage through such straits.
Additional Information
A strait is a narrow body of water that connects two larger bodies of water.
It may be formed by a fracture in an isthmus, a narrow body of land that connects two bodies of water. Tectonic shifts can lead to straits like this. One strait that was formed by tectonic activity is the Strait of Gibraltar, the only link between the Mediterranean Sea and the Atlantic Ocean. The Strait of Gibraltar is actually closing, as the African tectonic plate slides north. In a few thousand years, the Strait of Gibraltar will be the Isthmus of Gibraltar, and the Mediterranean will be a large, salty, inland sea.
If fractures in an isthmus are created by human activity, the straits are usually called canals. The Suez Canal was constructed in 1869 as a waterway between the Mediterranean Sea and the Red Sea. The Suez Canal allows transportation between Europe and Asia without having to go around the entire continent of Africa. It is an important economic strait.
A strait can also be formed by a body of water overflowing land that has subsided or has been eroded. The Bosporus, which links the Black Sea and the Aegean Sea, was formed this way. Land at the southwestern edge of the Black Sea eroded and crumbled, creating a strait. Although scientists know that the Black Sea was once an enclosed lake, they do not know for sure whether the Black Sea flooded into the Aegean, or the Aegean flooded into the Black Sea. The Bosporus is an extremely important strait, separating the continents of Europe and Asia. Besides two entire continents, the Bosporus also separates a single country. It splits the European part of Turkey, called Thrace, and the Asian part, called Anatolia.
Strategic Straits
Historically, straits have had great strategic importance. Whoever controls a strait is likely to control the sea and shipping routes of the entire region.
The Strait of Hormuz connects the Persian Gulf and a part of the Arabian Sea called the Gulf of Oman. Great quantities of petroleum from Middle Eastern states are shipped through the Strait of Hormuz.
The strait is jointly controlled by Oman, the United Arab Emirates, and Iran. These countries, which all export oil, are rarely in dispute with each other. They all have military centers in the region. Countries that import oil from the region also patrol the Strait of Hormuz. Sometimes, these military patrols can lead to conflict. In 2008, the United States accused Iran of harassing U.S. warships with small speedboats. Iran denied the allegations. The two countries were close to conflict for months before the dispute was settled without violence.
Their narrow passages can make some straits difficult to navigate. The Strait of Magellan is a very thin waterway between the southern tip of South America and the group of islands known as Tierra del Fuego. The strait links the Pacific and Atlantic Oceans. The stormy waters south of Tierra del Fuego (close to Antarctica) made the Strait of Magellan, to the north, more attractive to mariners. Although the landmasses protect the strait from harsh Antarctic weather, the Strait of Magellan is still difficult to navigate. It is narrow and the islands of Tierra del Fuego can lead to confusion in stormy weather. The temperatures can reach freezing. Strong wind and waves make visibility and steering complex.
Whaling ships of the 19th century, sailing from the East Coast of the United States to the whaling grounds of the South Pacific, would sometimes stay for weeks around the Strait of Magellan, waiting for calm, clear days for passage.
#175 This is Cool » White Blood Cells » 2025-08-26 21:42:13
- Jai Ganesh
- Replies: 0
White Blood Cells
Gist
White Blood Cells are components of the immune system that protect the body from infection and disease. They circulate in the blood and lymph, and are produced in the bone marrow from stem cells. The main types of white blood cells include lymphocytes (T cells and B cells), monocytes, and granulocytes (neutrophils, eosinophils, and basophils), each with a distinct role in detecting and destroying pathogens, producing antibodies, and engulfing foreign materials.
White blood cells (WBCs), or leukocytes, are a crucial part of the immune system, produced in the bone marrow and circulating in the blood and lymph tissue to fight infections, other diseases, and foreign invaders. There are five main types—neutrophils, eosinophils, basophils, lymphocytes, and monocytes—each with specific roles in the body's defense. A white blood cell count (WBC count) is a common blood test that measures the number of WBCs, with an elevated count often indicating an infection or inflammatory condition.
Summary
White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign entities. White blood cells are generally larger than red blood cells. They include three main subtypes: granulocytes, lymphocytes and monocytes.
All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. All white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cells are usually classified by cell lineage (myeloid cells or lymphoid cells). White blood cells are part of the body's immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), and agranulocytes (monocytes, and lymphocytes (T cells and B cells)). Myeloid cells (myelocytes) include neutrophils, eosinophils, mast cells, basophils, and monocytes.[6] Monocytes are further subdivided into dendritic cells and macrophages. Monocytes, macrophages, and neutrophils are phagocytic. Lymphoid cells (lymphocytes) include T cells (subdivided into helper T cells, memory T cells, cytotoxic T cells), B cells (subdivided into plasma cells and memory B cells), and natural killer cells. Historically, white blood cells were classified by their physical characteristics (granulocytes and agranulocytes), but this classification system is less frequently used now. Produced in the bone marrow, white blood cells defend the body against infections and disease. An excess of white blood cells is usually due to infection or inflammation. Less commonly, a high white blood cell count could indicate certain blood cancers or bone marrow disorders.
The number of leukocytes in the blood is often an indicator of disease, and thus the white blood cell count is an important subset of the complete blood count. The normal white cell count is usually between 4 billion/L and 11 billion/L. In the US, this is usually expressed as 4,000 to 11,000 white blood cells per microliter of blood. White blood cells make up approximately 1% of the total blood volume in a healthy adult, making them substantially less numerous than the red blood cells at 40% to 45%. However, this 1% of the blood makes a huge difference to health because immunity depends on it. An increase in the number of leukocytes over the upper limits is called leukocytosis. It is normal when it is part of healthy immune responses, which happen frequently. It is occasionally abnormal when it is neoplastic or autoimmune in origin. A decrease below the lower limit is called leukopenia, which indicates a weakened immune system.
Details
White blood cells are a part of your immune system that protects your body from infection. These cells circulate through your bloodstream and tissues to respond to injury or illness by attacking any unknown organisms that enter your body.
What are white blood cells?
White blood cells, also known as leukocytes, are responsible for protecting your body from infection. As part of your immune system, white blood cells circulate in your blood and respond to injury or illness.
Function:
What do white blood cells do?
White blood cells protect your body against infection. As your white blood cells travel through your bloodstream and tissues, they locate the site of an infection and act as an army general to notify other white blood cells of their location to help defend your body from an attack of an unknown organism. Once your white blood cell army arrives, they fight the invader by producing antibody proteins to attach to the organism and destroy it.
Anatomy:
Where are white blood cells located?
Your white blood cells are in your bloodstream and travel through blood vessel walls and tissues to locate the site of an infection.
What do white blood cells look like?
Contrary to their name, white blood cells are colorless but can appear as a very light purple to pink color when examined under a microscope and colored with dye. These extremely tiny cells have a round shape with a distinct center membrane (nucleus).
How big are white blood cells?
You can only see white blood cells under a microscope, as they are extremely small.
How many white blood cells are in my body?
White blood cells account for 1% of your blood. There are more red blood cells in your body than white blood cells.
How are white blood cells formed?
White blood cell formation occurs in the soft tissue inside of your bones (bone marrow). Two types of white blood cells (lymphocytes) grow in the thymus gland (T cells) and lymph nodes and spleen (B cells).
What are white blood cells made of?
White blood cells originate from cells that morph into other cells in the body (stem cell) within the soft tissue of your bones (bone marrow).
What are the types of white blood cells?
There are five types of white blood cells:
* Neutrophils: Help protect your body from infections by killing bacteria, fungi and foreign debris.
* Lymphocytes: Consist of T cells, natural killer cells and B cells to protect against viral infections and produce proteins to help you fight infection (antibodies).
* Eosinophils: Identify and destroy parasites, cancer cells and assists basophils with your allergic response.
* Basophils: Produce an allergic response like coughing, sneezing or a runny nose.
* Monocytes: Defend against infection by cleaning up damaged cells.
Conditions and DisordersWhat are the common conditions and disorders that affect white blood cells?
If you have a low white blood cell count, you are likely to get infections (leukopenia). If your white blood cell count is too high (leukocytosis), you may have an infection or an underlying medical condition like leukemia, lymphoma or an immune disorder.
What are common signs or symptoms of white blood cell conditions?
Symptoms of white blood cell conditions, where you may have a count that is too high or too low, include:
* Fever, body aches and chills.
* Wound that is red, swollen, oozes pus or won’t heal.
* Frequent infections.
* Persistent cough or difficulty breathing.
What is a normal white blood cell count?
It is normal for you to produce nearly 100 billion white blood cells each day. After completing a blood draw, a test counts your white blood cells, which equals number of cells per microliter of blood. The normal white blood cell count ranges between 4,000 and 11,000 cells per microliter.
What are common tests to check the number of white blood cells?
A complete blood count (CBC) test identifies information about the cells in your blood. A lab completes this test after a medical professional draws your blood and examines your white and red blood cell count.
White blood cells scan is a test to detect infection or abscesses in your body’s soft tissues. This test involves withdrawing your blood, separating the white blood cells from the sample, tagging them with a radioactive isotope, returning those white blood cells back into your body, then an imaging test will identify areas that show infection or abscess on your body.
What causes a low white blood cell count?
Causes of low white blood cell count include:
* Bone marrow failure (aplastic anemia).
* Bone marrow attacked by cancer cells (leukemia).
* Drug exposure (chemotherapy).
* Vitamin deficiency (B12).
* HIV/AIDS.
A blood test with fewer than 4,000 cells per microliter of blood diagnoses low white blood cells.
What causes a high white blood cell count?
Causes of high white blood cell count include:
* Autoimmune disorders (lupus, rheumatoid arthritis).
* Viral infections (mononucleosis).
* Bacterial infections (sepsis).
* Physical injury or stress.
* Leukemia or Hodgkins disease.
* Allergies.
A blood test with more than 11,000 cells per microliter of blood diagnoses high white blood cells.
What are common treatments for white blood cell disorders?
Treatment for white blood cell disorders vary based on the diagnosis and severity of the condition. Treatment ranges from:
* Taking vitamins.
* Taking antibiotics.
* Surgery to replace or repair bone marrow.
* Blood transfusion.
* Stem cell transplant.
Care:
How do I take care of my white blood cells?
You can take care of your white blood cells by:
* Practicing good hygiene to prevent infection.
* Taking vitamins to boost your immune system.
* Treating medical conditions where white blood cell disorders are a side effect.
White blood cells serve as your first line of defense against injury or illness. Keep your white blood cells healthy by taking vitamins to boost your immune system and practicing good hygiene to prevent infection. If you experience any symptoms like fever and chills, frequent infection, persistent cough or difficulty breathing, contact your healthcare provider to test if your white blood cell count is abnormal.
Additional Information
A white blood cell is a cellular component of the blood that lacks hemoglobin, has a nucleus, is capable of motility, and defends the body against infection and disease by ingesting foreign materials and cellular debris, by destroying infectious agents and cancer cells, or by producing antibodies.
Characteristics of white blood cells
In adults, the bone marrow produces 60 to 70 percent of the white cells (i.e., the granulocytes). The lymphatic tissues, particularly the thymus, the spleen, and the lymph nodes, produce the lymphocytes (comprising 20 to 30 percent of the white cells). The reticuloendothelial tissues of the spleen, liver, lymph nodes, and other organs produce the monocytes (4 to 8 percent of the white cells). A healthy adult human has between 4,500 and 11,000 white blood cells per cubic millimetre of blood. Fluctuations in white cell number occur during the day; lower values are obtained during rest and higher values during exercise.
The survival of white blood cells, as living cells, depends on their continuous production of energy. The chemical pathways utilized are more complex than those of the red cells and are similar to those of other tissue cells. White cells, containing a nucleus and able to produce ribonucleic acid (RNA), can synthesize protein.
Although white cells are found in the circulation, most occur outside the circulation, within tissues, where they fight infections; the few in the bloodstream are in transit from one site to another. As living cells, their survival depends on their continuous production of energy. The chemical pathways utilized are more complex than those of red blood cells and are similar to those of other tissue cells. White cells, containing a nucleus and able to produce ribonucleic acid (RNA), can synthesize protein. White cells are highly differentiated for their specialized functions, and they do not undergo cell division (mitosis) in the bloodstream; however, some retain the capability of mitosis. On the basis of their appearance under a light microscope, white cells are grouped into three major classes—lymphocytes, granulocytes, and monocytes—each of which carries out somewhat different functions.
Major classes of white blood cells
Lymphocytes, which are further divided into B cells and T cells, are responsible for the specific recognition of foreign agents and their subsequent removal from the host. B lymphocytes secrete antibodies, which are proteins that bind to foreign microorganisms in body tissues and mediate their destruction. Typically, T cells recognize virally infected or cancerous cells and destroy them, or they serve as helper cells to assist the production of antibody by B cells. Also included in this group are natural killer (NK) cells, so named for their inherent ability to kill a variety of target cells. In a healthy person, about 25 to 33 percent of white blood cells are lymphocytes.
Granulocytes, the most numerous of the white cells, rid the body of large pathogenic organisms such as protozoans or helminths and are also key mediators of allergy and other forms of inflammation. These cells contain many cytoplasmic granules, or secretory vesicles, that harbour potent chemicals important in immune responses. They also have multilobed nuclei, and because of this they are often called polymorphonuclear cells. On the basis of how their granules take up dye in the laboratory, granulocytes are subdivided into three categories: neutrophils, eosinophils, and basophils. The most numerous of the granulocytes—making up 50 to 80 percent of all white cells—are neutrophils. They are often one of the first cell types to arrive at a site of infection, where they engulf and destroy the infectious microorganisms through a process called phagocytosis. Eosinophils and basophils, as well as the tissue cells called mast cells, typically arrive later. The granules of basophils and of the closely related mast cells contain a number of chemicals, including histamine and leukotrienes, that are important in inducing allergic inflammatory responses. Eosinophils destroy parasites and also help to modulate inflammatory responses.
Monocytes, which constitute between 4 and 8 percent of the total number of white blood cells in the blood, move from the blood to sites of infection, where they differentiate further into macrophages. These cells are scavengers that phagocytose whole or killed microorganisms and are therefore effective at direct destruction of pathogens and cleanup of cellular debris from sites of infection. Neutrophils and macrophages are the main phagocytic cells of the body, but macrophages are much larger and longer-lived than neutrophils. Some macrophages are important as antigen-presenting cells, cells that phagocytose and degrade microbes and present portions of these organisms to T lymphocytes, thereby activating the specific acquired immune response.
Diseases of white blood cells
Specific types of cells are associated with different illnesses and reflect the special function of that cell type in body defense. In general, newborns have a high white blood cell count that gradually falls to the adult level during childhood. An exception is the lymphocyte count, which is low at birth, reaches its highest levels in the first four years of life, and thereafter falls gradually to a stable adult level.
An abnormal increase in white cell number is known as leukocytosis. This condition is usually caused by an increase in the number of granulocytes (especially neutrophils), some of which may be immature (myelocytes). White cell count may increase in response to intense physical exertion, convulsions, acute emotional reactions, pain, pregnancy, labour, and certain disease states, such as infections and intoxications.
A large increase in the numbers of white blood cells in the circulation or bone marrow is a sign of leukemia, a type of cancer of the blood-forming tissues. Some types of leukemia have been related to radiation exposure, as noted in the Japanese population exposed to the first atomic bomb at Hiroshima; other evidence suggests hereditary susceptibility. A number of different leukemias are classified according to the course of the disease and the predominant type of white blood cell involved. For example, myelogenous leukemia affects granulocytes and monocytes, white blood cells that destroy bacteria and some parasites.
An abnormal decrease in white blood cell numbers is known as leukopenia. The count may decrease in response to certain types of infections or drugs or in association with certain conditions, such as chronic anemia, malnutrition, or anaphylaxis.
Certain types of infections are characterized from the beginning by an increase in the number of small lymphocytes unaccompanied by increases in monocytes or granulocytes. Such lymphocytosis is usually of viral origin. Moderate degrees of lymphocytosis are encountered in certain chronic infections, such as tuberculosis and brucellosis. Infectious mononucleosis, caused by the Epstein-Barr virus, is associated with the appearance of unusually large lymphocytes (atypical lymphocytes). These cells represent part of the complex defense mechanism against the virus, and they disappear from the blood when the attack of infectious mononucleosis subsides.
