Daily Archives: May 11, 2016

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A Grebe


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Love, respect and protect


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The Virtue Continuum


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From Erin Brockovich: LADWP Crews Test For Water Contamination Concerns In South LA « CBS Los Angeles


http://losangeles.cbslocal.com/2016/05/11/water-contamination-concerns-south-la/

City of Los Angeles… we told you… this is only going to get worse. My post doesn’t match the “disinformation” in this news report… but remember, you heard it here first.

The City of Los Angeles (much like Flint, Michigan) switched its water source. Most of the City of Los Angeles water was from Sierra Nevada snow melt… from the Owens Valley. Now most of the water is from the Sacramento Delta… the change in water quality brought about drastic changes in treatment… changes that have begun to take its toll on the pipes throughout the city.

It all begins with “month long flushing”… and ends with a destroyed distribution system infrastructure. The Los Angeles system had awesome water quality… it was balanced. Sacramento Delta… well it’s not so good…

Loaded with organics, pesticides, herbicides, pharmaceuticals… and other fun stuff. Rather then treat Los Angeles water properly… removing the organics, pesticides, herbicides, pharmaceuticals… it leaves most of them in the drinking water and masks the chemical reactions by adding ammonia to the drinking water.

The City of Los Angeles has choices… adding ammonia is a really bad choice. Let’s hope they reconsider and make the right choice… before it’s too late.

Anza Borrego Desert State Park, California. Borrego Palm Canyon Trail.


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Anza Borrego Desert State Park, California.   Borrego Palm Canyon Trail.

deathvalleyjim.com/2012/06/23/zabriskie-point-death-valley-61612/


http://deathvalleyjim.com/2012/06/23/zabriskie-point-death-valley-61612/

Nine million years ago an ancient lake covered the area around Zabriskie. During the millions of years that the lake existed, sediments collected at the bottom of the lake in the form of saline muds and gravel.

What we see today is a direct result of the climate becoming more and more arid, which caused the lake to dry up. During the same time that the lake was drying the valley began widening and sinking, and the Black Mountains began to lift. This caused the land to tilt, and erode into the badlands formation that we  see today.

Live with dignity, quoted by Jim Morrison


http://cuvintecelebre.ro/demnitate/

Documentul care confirmă cel mai NEGRU SCENARIU pentru România. Este dincolo de orice îndoială că SITUAŢIA E INEVITABILĂ


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Documentul care confirmă cel mai NEGRU SCENARIU pentru România. Este dincolo de orice îndoială că SITUAŢIA E INEVITABILĂ

Poziţia geografică şi dezvoltarea României şi Bulgariei vor dezavantaja cele două state în viitor. Cele două vor fi prinse din ce în ce mai puternic în conflictele şi crizele dintre vecinii mai puternici afirmă analişti de la Stratfor, în analiza publicată luni.

Bulgaria şi România vor deveni “tot mai implicate” în cele mai iportante crize ale Eurasiei, dar ” ca şi în trecut mai mult vor reacţiona la evenimente decât să-şi realizeze interesele”.

“Ambele ţări sunt încă o dată prinse în mijlocul conflictelor şi crizelor între marile puteri vecine, în special criza refugiaţilor dintre Europa şi Turcia şi conflictul din Ucraina dintre Rusia şi Occident. România şi Bulgaria vor face eforturi pentru a-şi promova interesele în aceste situaţii tensionate care evoluează”, consideră analişti de la Stratfor citaţi de cei de la agenţia bulgară Focus.

Agenţia mai reţine în analiza sa că în trecut cele două ţări au ”o lungă istorie  în care au fost influenţate de ţările vecine mai puternice.”Situate în colţul de sud-est a Europei în regiunea balcanică, România a fost o dată dominat de Imperiul Austro-Ungar, în timp ce Bulgaria a fost condusă de turci. În timpul Războiului Rece, ambele ţări au fost absorbite în calitate de state satelit de către Uniunea Sovietică, iar Moscova le-a modelat  în mare măsură politicile externe şi de apărare. Când Uniunea Sovietică s-a prăbuşit, România şi Bulgaria au adoptat o cale prooccidentală, au aderat la NATO în 2004 şi la UE în 2007”.

Din analiza citată reiese că tulburările vor afecta ambele ţări, dar criza refugiaţilor va lovi mai mult Sofia, iar cea dintre NATO şi Rusia va fi mai complicată pentru Bucureşti.

Criza refugiaţilor va încurca eforturile ambelor ţări de a adera la spatiul Schengen, din cauza “măsurilor de limitare a circulaţiei între ţări adoptate de statele UE”.

În topul provocărilor economice şi politice generate de criză se află ”marele val de solicitanţi de azil care a lovit Europa”. Acasta invazie  ”agaravează diferenţele care ameninţă să fragmenteze şi mai tare blocul comunitar şi reduce securitatea generată de acesta”. Mai mult de 1 milion de migranţi au ajuns pe continent doar în 2015, în special din zonele de conflict din Siria, Irak şi Afganistan.

Cu toate acestea criza refugiaţilor nu a afectat până acum cu adevărat România şi Bulgaria, nici una dintre ţări nefiind pe traseul initial al migranţilor care trece prin Turcia, Grecia şi Balcanii de Vest către  Austria, Germania şi Europa de Nord. România şi Bulgaria au primit refugiaţi în cadrul programului de reinstalare al UE, dar numărul a acestora fost neglijabil.

Stratfor consideră însă că pericolul vine de la faptul că rutele migranţilor se pot schimba şi o mare parte dintre refugiaţi se vor deplasa prin România şi Bulgaria şi cu atât mai mult dacă acordul dintre UE şi Turcia cu privire la refugiaţi se va prăbuşi. Închiderea graniţei dintre Macedonia şi Grecia, în martie a creat posibilitatea ca migranţii să fie deviaţi către Italia ”de-a lungul unei rute de est”, care include Bulgaria şi România.

Într-un astfel de context, Bulgaria va fi mai vulnerabilă la fluxurile de refugiaţi decât România. Acastă situaţie se datorează, după cum consideră analiştii, ”sensibilităţilor etnice şi religioase mai mari din Bulgaria unde există un număr important  de minoritari turci şi unde în ansambu populaţia este mai redusă”. Vecinii noştrii de la sud au doar 7,2 milioane de persoane, spre deosebire de cele 20 de milioane ale României. Prim-ministrul bulgar Boiko Borisov se opune ca ţara sa să devină o “rută alternativă” pentru migranţi, şi  face planuri cu Macedonia pentru organizarea unor  operaţiuni terestre şi de aeriene comune pentru a “asigura un control la frontieră.” Bulgaria a construit chiar şi un gard la frontiera sa cu Turcia la mijlocul anului 2015 ca o măsură de precauţie “, se mai arată în analiza Stratfor.

În ceea ce priveşte criza din Ucraina, analiştii americani consideră că România şi Bulgaria care sunt membre NATO vor accepta şi chiar încuraja întărirea prezenţei militare a Alianţei pe flancul estic. Spre deosebire de România însă ”Sofia îşi va menţine relaţiile  sale cu Moscova”.

“Conflictul ucrainean şi tensiunile ulterioare în relaţiile dintre Rusia şi Occident sunt, de asemenea, în măsură să influenţeze foarte mult  România şi Bulgaria. Ambele ţări sunt preocupate de activităţile Moscovei, în Ucraina, din apropiere şi în alte părţi din fosta periferie sovietică şiîngrijorate de potenţialul de conflict care riscă să se extindă peste graniţele lor”, mai afirmă cei de la Statfor.

Totodată cele două state  au devenit un teatru important de desfăşurare de armamant al Alianţei în Europa de Est, dar şi pentru exerciţii militare ale NATO şi SUA .

”Cu toate acestea, din cauza legăturilor culturale şi istorice comune, Sofia este mai conciliantă faţă de Moscova decât este Bucureştiul”, se mai arată în analiza citată. Spre deosebire de România care ” are un conflict politic direct cu Rusia în Moldova, unde  cele două ţări concurează pentru influenţă”, Bulgaria nu are nici o astfel de zonă în litigiu cu Rusia.

Mai mult decât atât, dependenţa totală a Bulgariei de energia rusească restrânge locul de manevră politică în cazul Sofiei. Din acest punct de vedere libertatea României este mult mai mare, susţin analiştii deoarece Bucureştiul ” produce o mare parte din  gazele  naturale şi petrolul necesare şi se bazează mult mai puţin pe exporturile ruseşti”.

”Şi nu în cele din urmă, oligarhii bulgari şi anumiţi politicieni au în general legături mai strânse cu Rusia, decât omologii lor români “, se mai arată în analiza Stratfor.

From Wikipedia :the immune system


https://en.wikipedia.org/wiki/Immunoglobulin_M?wprov=sfla1 The immune system is a system of many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism’s own healthy tissue. In many species, the immune system can be classified into subsystems, such as the innate immune system versus the adaptive immune system, or humoral immunity versus cell-mediated immunity. In humans, the blood–brain barrier, blood–cerebrospinal fluid barrier, and similar fluid–brain barriers separate the peripheral immune system from the neuroimmune system which protects the brain.

A scanning electron microscope image of a single neutrophil (yellow), engulfing anthrax bacteria (orange)
Pathogens can rapidly evolve and adapt, and thereby avoid detection and neutralization by the immune system; however, multiple defense mechanisms have also evolved to recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess a rudimentary immune system, in the form of enzymes that protect against bacteriophage infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants and invertebrates. These mechanisms include phagocytosis, antimicrobial peptides called defensins, and the complement system. Jawed vertebrates, including humans, have even more sophisticated defense mechanisms,[1] including the ability to adapt over time to recognize specific pathogens more efficiently. Adaptive (or acquired) immunity creates immunological memory after an initial response to a specific pathogen, leading to an enhanced response to subsequent encounters with that same pathogen. This process of acquired immunity is the basis of vaccination.

Disorders of the immune system can result in autoimmune diseases, inflammatory diseases and cancer.[2] Immunodeficiency occurs when the immune system is less active than normal, resulting in recurring and life-threatening infections. In humans, immunodeficiency can either be the result of a genetic disease such as severe combined immunodeficiency, acquired conditions such as HIV/AIDS, or the use of immunosuppressive medication. In contrast, autoimmunity results from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto’s thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, and systemic lupus erythematosus. Immunology covers the study of all aspects of the immune system.

History of immunology
For more details on this topic, see History of immunology.
Immunology is a science that examines the structure and function of the immune system. It originates from medicine and early studies on the causes of immunity to disease. The earliest known reference to immunity was during the plague of Athens in 430 BC. Thucydides noted that people who had recovered from a previous bout of the disease could nurse the sick without contracting the illness a second time.[3] In the 18th century, Pierre-Louis Moreau de Maupertuis made experiments with scorpion venom and observed that certain dogs and mice were immune to this venom.[4] This and other observations of acquired immunity were later exploited by Louis Pasteur in his development of vaccination and his proposed germ theory of disease.[5] Pasteur’s theory was in direct opposition to contemporary theories of disease, such as the miasma theory. It was not until Robert Koch’s 1891 proofs, for which he was awarded a Nobel Prize in 1905, that microorganisms were confirmed as the cause of infectious disease.[6] Viruses were confirmed as human pathogens in 1901, with the discovery of the yellow fever virus by Walter Reed.[7]

Immunology made a great advance towards the end of the 19th century, through rapid developments, in the study of humoral immunity and cellular immunity.[8] Particularly important was the work of Paul Ehrlich, who proposed the side-chain theory to explain the specificity of the antigen-antibody reaction; his contributions to the understanding of humoral immunity were recognized by the award of a Nobel Prize in 1908, which was jointly awarded to the founder of cellular immunology, Elie Metchnikoff.[9]

Layered defense
The immune system protects organisms from infection with layered defenses of increasing specificity. In simple terms, physical barriers prevent pathogens such as bacteria and viruses from entering the organism. If a pathogen breaches these barriers, the innate immune system provides an immediate, but non-specific response. Innate immune systems are found in all plants and animals.[10] If pathogens successfully evade the innate response, vertebrates possess a second layer of protection, the adaptive immune system, which is activated by the innate response. Here, the immune system adapts its response during an infection to improve its recognition of the pathogen. This improved response is then retained after the pathogen has been eliminated, in the form of an immunological memory, and allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered.[11]

More information: Innate immune system, Adaptive immune system …
Both innate and adaptive immunity depend on the ability of the immune system to distinguish between self and non-self molecules. In immunology, self molecules are those components of an organism’s body that can be distinguished from foreign substances by the immune system.[12] Conversely, non-self molecules are those recognized as foreign molecules. One class of non-self molecules are called antigens (short for antibody generators) and are defined as substances that bind to specific immune receptors and elicit an immune response.[13]

Innate immune system
For more details on this topic, see Innate immune system.
Microorganisms or toxins that successfully enter an organism encounter the cells and mechanisms of the innate immune system. The innate response is usually triggered when microbes are identified by pattern recognition receptors, which recognize components that are conserved among broad groups of microorganisms,[14] or when damaged, injured or stressed cells send out alarm signals, many of which (but not all) are recognized by the same receptors as those that recognize pathogens.[15] Innate immune defenses are non-specific, meaning these systems respond to pathogens in a generic way.[13] This system does not confer long-lasting immunity against a pathogen. The innate immune system is the dominant system of host defense in most organisms.[10]

Surface barriers
Several barriers protect organisms from infection, including mechanical, chemical, and biological barriers. The waxy cuticle of many leaves, the exoskeleton of insects, the shells and membranes of externally deposited eggs, and skin are examples of mechanical barriers that are the first line of defense against infection.[13] However, as organisms cannot be completely sealed from their environments, other systems act to protect body openings such as the lungs, intestines, and the genitourinary tract. In the lungs, coughing and sneezing mechanically eject pathogens and other irritants from the respiratory tract. The flushing action of tears and urine also mechanically expels pathogens, while mucus secreted by the respiratory and gastrointestinal tract serves to trap and entangle microorganisms.[16]

Chemical barriers also protect against infection. The skin and respiratory tract secrete antimicrobial peptides such as the β-defensins.[17] Enzymes such as lysozyme and phospholipase A2 in saliva, tears, and breast milk are also antibacterials.[18][19] Vaginal secretions serve as a chemical barrier following menarche, when they become slightly acidic, while semen contains defensins and zinc to kill pathogens.[20][21] In the stomach, gastric acid and proteases serve as powerful chemical defenses against ingested pathogens.

Within the genitourinary and gastrointestinal tracts, commensal flora serve as biological barriers by competing with pathogenic bacteria for food and space and, in some cases, by changing the conditions in their environment, such as pH or available iron.[22] This reduces the probability that pathogens will reach sufficient numbers to cause illness. However, since most antibiotics non-specifically target bacteria and do not affect fungi, oral antibiotics can lead to an “overgrowth” of fungi and cause conditions such as a vaginal candidiasis (a yeast infection).[23] There is good evidence that re-introduction of probiotic flora, such as pure cultures of the lactobacilli normally found in unpasteurized yogurt, helps restore a healthy balance of microbial populations in intestinal infections in children and encouraging preliminary data in studies on bacterial gastroenteritis, inflammatory bowel diseases, urinary tract infection and post-surgical infections.[24][25][26]

Inflammation
For more details on this topic, see Inflammation.
Inflammation is one of the first responses of the immune system to infection.[27] The symptoms of inflammation are redness, swelling, heat, and pain, which are caused by increased blood flow into tissue. Inflammation is produced by eicosanoids and cytokines, which are released by injured or infected cells. Eicosanoids include prostaglandins that produce fever and the dilation of blood vessels associated with inflammation, and leukotrienes that attract certain white blood cells (leukocytes).[28][29] Common cytokines include interleukins that are responsible for communication between white blood cells; chemokines that promote chemotaxis; and interferons that have anti-viral effects, such as shutting down protein synthesis in the host cell.[30] Growth factors and cytotoxic factors may also be released. These cytokines and other chemicals recruit immune cells to the site of infection and promote healing of any damaged tissue following the removal of pathogens.[31]

Complement system
For more details on this topic, see Complement system.
The complement system is a biochemical cascade that attacks the surfaces of foreign cells. It contains over 20 different proteins and is named for its ability to “complement” the killing of pathogens by antibodies. Complement is the major humoral component of the innate immune response.[32][33] Many species have complement systems, including non-mammals like plants, fish, and some invertebrates.[34]

In humans, this response is activated by complement binding to antibodies that have attached to these microbes or the binding of complement proteins to carbohydrates on the surfaces of microbes. This recognition signal triggers a rapid killing response.[35] The speed of the response is a result of signal amplification that occurs following sequential proteolytic activation of complement molecules, which are also proteases. After complement proteins initially bind to the microbe, they activate their protease activity, which in turn activates other complement proteases, and so on. This produces a catalytic cascade that amplifies the initial signal by controlled positive feedback.[36] The cascade results in the production of peptides that attract immune cells, increase vascular permeability, and opsonize (coat) the surface of a pathogen, marking it for destruction. This deposition of complement can also kill cells directly by disrupting their plasma membrane.[32]

Cellular barriers

A scanning electron microscope image of normal circulating human blood. One can see red blood cells, several knobby white blood cells including lymphocytes, a monocyte, a neutrophil, and many small disc-shaped platelets.
Leukocytes (white blood cells) act like independent, single-celled organisms and are the second arm of the innate immune system.[13] The innate leukocytes include the phagocytes (macrophages, neutrophils, and dendritic cells), mast cells, eosinophils, basophils, and natural killer cells. These cells identify and eliminate pathogens, either by attacking larger pathogens through contact or by engulfing and then killing microorganisms.[34] Innate cells are also important mediators in the activation of the adaptive immune system.[11]

Phagocytosis is an important feature of cellular innate immunity performed by cells called ‘phagocytes’ that engulf, or eat, pathogens or particles. Phagocytes generally patrol the body searching for pathogens, but can be called to specific locations by cytokines.[13] Once a pathogen has been engulfed by a phagocyte, it becomes trapped in an intracellular vesicle called a phagosome, which subsequently fuses with another vesicle called a lysosome to form a phagolysosome. The pathogen is killed by the activity of digestive enzymes or following a respiratory burst that releases free radicals into the phagolysosome.[37][38] Phagocytosis evolved as a means of acquiring nutrients, but this role was extended in phagocytes to include engulfment of pathogens as a defense mechanism.[39] Phagocytosis probably represents the oldest form of host defense, as phagocytes have been identified in both vertebrate and invertebrate animals.[40]

Neutrophils and macrophages are phagocytes that travel throughout the body in pursuit of invading pathogens.[41] Neutrophils are normally found in the bloodstream and are the most abundant type of phagocyte, normally representing 50% to 60% of the total circulating leukocytes.[42] During the acute phase of inflammation, particularly as a result of bacterial infection, neutrophils migrate toward the site of inflammation in a process called chemotaxis, and are usually the first cells to arrive at the scene of infection. Macrophages are versatile cells that reside within tissues and produce a wide array of chemicals including enzymes, complement proteins, and regulatory factors such as interleukin 1.[43] Macrophages also act as scavengers, ridding the body of worn-out cells and other debris, and as antigen-presenting cells that activate the adaptive immune system.[11]

Dendritic cells (DC) are phagocytes in tissues that are in contact with the external environment; therefore, they are located mainly in the skin, nose, lungs, stomach, and intestines.[44] They are named for their resemblance to neuronal dendrites, as both have many spine-like projections, but dendritic cells are in no way connected to the nervous system. Dendritic cells serve as a link between the bodily tissues and the innate and adaptive immune systems, as they present antigens to T cells, one of the key cell types of the adaptive immune system.[44]

Mast cells reside in connective tissues and mucous membranes, and regulate the inflammatory response.[45] They are most often associated with allergy and anaphylaxis.[42] Basophils and eosinophils are related to neutrophils. They secrete chemical mediators that are involved in defending against parasites and play a role in allergic reactions, such as asthma.[46] Natural killer (NK cells) cells are leukocytes that attack and destroy tumor cells, or cells that have been infected by viruses.[47]

Natural killer cells
Main article: Natural killer cell
Natural killer cells, or NK cells, are a component of the innate immune system which does not directly attack invading microbes. Rather, NK cells destroy compromised host cells, such as tumor cells or virus-infected cells, recognizing such cells by a condition known as “missing self.” This term describes cells with low levels of a cell-surface marker called MHC I (major histocompatibility complex) – a situation that can arise in viral infections of host cells.[34] They were named “natural killer” because of the initial notion that they do not require activation in order to kill cells that are “missing self.” For many years it was unclear how NK cells recognize tumor cells and infected cells. It is now known that the MHC makeup on the surface of those cells is altered and the NK cells become activated through recognition of “missing self”. Normal body cells are not recognized and attacked by NK cells because they express intact self MHC antigens. Those MHC antigens are recognized by killer cell immunoglobulin receptors (KIR) which essentially put the brakes on NK cells.[48]

Adaptive immune system
For more details on this topic, see Adaptive immune system.
The adaptive immune system evolved in early vertebrates and allows for a stronger immune response as well as immunological memory, where each pathogen is “remembered” by a signature antigen.[49] The adaptive immune response is antigen-specific and requires the recognition of specific “non-self” antigens during a process called antigen presentation. Antigen specificity allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells. The ability to mount these tailored responses is maintained in the body by “memory cells”. Should a pathogen infect the body more than once, these specific memory cells are used to quickly eliminate it.

Lymphocytes
The cells of the adaptive Lymphocytes
The cells of the adaptive immune system are special types of leukocytes, called lymphocytes. B cells and T cells are the major types of lymphocytes and are derived from hematopoietic stem cells in the bone marrow.[34] B cells are involved in the humoral immune response, whereas T cells are involved in cell-mediated immune response.

Both B cells and T cells carry receptor molecules that recognize specific targets. T cells recognize a “non-self” target, such as a pathogen, only after antigens (small fragments of the pathogen) have been processed and presented in combination with a “self” receptor called a major histocompatibility complex (MHC) molecule. There are two major subtypes of T cells: the killer T cell and the helper T cell. In addition there are regulatory T cells which have a role in modulating immune response. Killer T cells only recognize antigens coupled to Class I MHC molecules, while helper T cells and regulatory T cells only recognize antigens coupled to Class II MHC molecules. These two mechanisms of antigen presentation reflect the different roles of the two types of T cell. A third, minor subtype are the γδ T cells that recognize intact antigens that are not bound to MHC receptors.[50]

In contrast, the B cell antigen-specific receptor is an antibody molecule on the B cell surface, and recognizes whole pathogens without any need for antigen processing. Each lineage of B cell expresses a different antibody, so the complete set of B cell antigen receptors represent all the antibodies that the body can manufacture.[34]

Killer T cells
Killer T cells are a sub-group of T cells that kill cells that are infected with viruses (and other pathogens), or are otherwise damaged or dysfunctional.[51] As with B cells, each type of T cell recognizes a different antigen. Killer T cells are activated when their T cell receptor (TCR) binds to this specific antigen in a complex with the MHC Class I receptor of another cell. Recognition of this MHC:antigen complex is aided by a co-receptor on the T cell, called CD8. The T cell then travels throughout the body in search of cells where the MHC I receptors bear this antigen. When an activated T cell contacts such cells, it releases cytotoxins, such as perforin, which form pores in the target cell’s plasma membrane, allowing ions, water and toxins to enter. The entry of another toxin called granulysin (a protease) induces the target cell to undergo apoptosis.[52] T cell killing of host cells is particularly important in preventing the replication of viruses. T cell activation is tightly controlled and generally requires a very strong MHC/antigen activation signal, or additional activation signals provided by “helper” T cells (see below).[52]

Helper T cells

Function of T helper cells: Antigen-presenting cells (APCs) present antigen on their Class II MHC molecules (MHC2). Helper T cells recognize these, with the help of their expression of CD4 co-receptor (CD4+). The activation of a resting helper T cell causes it to release cytokines and other stimulatory signals (green arrows) that stimulate the activity of macrophages, killer T cells and B cells, the latter producing antibodies. The stimulation of B cells and macrophages succeeds a proliferation of T helper cells.
Helper T cells regulate both the innate and adaptive immune responses and help determine which immune responses the body makes to a particular pathogen.[53][54] These cells have no cytotoxic activity and do not kill infected cells or clear pathogens directly. They instead control the immune response by directing other cells to perform these tasks.

Helper T cells express T cell receptors (TCR) that recognize antigen bound to Class II MHC molecules. The MHC:antigen complex is also recognized by the helper cell’s CD4 co-receptor, which recruits molecules inside the T cell (e.g., Lck) that are responsible for the T cell’s activation. Helper T cells have a weaker association with the MHC:antigen complex than observed for killer T cells, meaning many receptors (around 200–300) on the helper T cell must be bound by an MHC:antigen in order to activate the helper cell, while killer T cells can be activated by engagement of a single MHC:antigen molecule. Helper T cell activation also requires longer duration of engagement with an antigen-presenting cell.[55] The activation of a resting helper T cell causes it to release cytokines that influence the activity of many cell types. Cytokine signals produced by helper T cells enhance the microbicidal function of macrophages and the activity of killer T cells.[13] In addition, helper T cell activation causes an upregulation of molecules expressed on the T cell’s surface, such as CD40 ligand (also called CD154), which provide extra stimulatory signals typically required to activate antibody-producing B cells.[56]

Gamma delta T cells
Gamma delta T cells (γδ T cells) possess an alternative T cell receptor (TCR) as opposed to CD4+ and CD8+ (αβ) T cells and share the characteristics of helper T cells, cytotoxic T cells and NK cells. The conditions that produce responses from γδ T cells are not fully understood. Like other ‘unconventional’ T cell subsets bearing invariant TCRs, such as CD1d-restricted Natural Killer T cells, γδ T cells straddle the border between innate and adaptive immunity.[57] On one hand, γδ T cells are a component of adaptive immunity as they rearrange TCR genes to produce receptor diversity and can also develop a memory phenotype. On the other hand, the various subsets are also part of the innate immune system, as restricted TCR or NK receptors may be used as pattern recognition receptors. For example, large numbers of human Vγ9/Vδ2 T cells respond within hours to common molecules produced by microbes, and highly restricted Vδ1+ T cells in epithelia respond to stressed epithelial cells.[50]

An antibody is made up of two heavy chains and two light chains. The unique variable region allows an antibody to recognize its matching antigen.[58]
B lymphocytes and antibodies
A B cell identifies pathogens when antibodies on its surface bind to a specific foreign antigen.[59] This antigen/antibody complex is taken up by the B cell and processed by proteolysis into peptides. The B cell then displays these antigenic peptides on its surface MHC class II molecules. This combination of MHC and antigen attracts a matching helper T cell, which releases lymphokines and activates the B cell.[60] As the activated B cell then begins to divide, its offspring (plasma cells) secrete millions of copies of the antibody that recognizes this antigen. These antibodies circulate in blood plasma and lymph, bind to pathogens expressing the antigen and mark them for destruction by complement activation or for uptake and destruction by phagocytes. Antibodies can also neutralize challenges directly, by binding to bacterial toxins or by interfering with the receptors that viruses and bacteria use to infect cells.[61]

Alternative adaptive immune system
Evolution of the adaptive immune system occurred in an ancestor of the jawed vertebrates. Many of the classical molecules of the adaptive immune system (e.g., immunoglobulins and T cell receptors) exist only in jawed vertebrates. However, a distinct lymphocyte-derived molecule has been discovered in primitive jawless vertebrates, such as the lamprey and hagfish. These animals possess a large array of molecules called Variable lymphocyte receptors (VLRs) that, like the antigen receptors of jawed vertebrates, are produced from only a small number (one or two) of genes. These molecules are believed to bind pathogenic antigens in a similar way to antibodies, and with the same degree of specificity.[62]

Immunological memory
For more details on this topic, see Immunity (medical).
When B cells and T cells are activated and begin to replicate, some of their offspring become long-lived memory cells. Throughout the lifetime of an animal, these memory cells remember each specific pathogen encountered and can mount a strong response if the pathogen is detected again. This is “adaptive” because it occurs during the lifetime of an individual as an adaptation to infection with that pathogen and prepares the immune system for future challenges. Immunological memory can be in the form of either passive short-term memory or active long-term memory.

Passive memory
Newborn infants have no prior exposure to microbes and are particularly vulnerable to infection. Several layers of passive protection are provided by the mother. During pregnancy, a particular type of antibody, called IgG, is transported from mother to baby directly across the placenta, so human babies have high levels of antibodies even at birth, with the same https://en.wikipedia.org/wiki/Immunoglobulin_M?wprov=sfla1

Historie-Tudor Duică: May 11th 330 AD. Constantinopole…


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Photo,
An artistic reconstruction of Constantinople in Late Antiquity.

May 11th 330 AD.

Constantinople, Greek: Κωνσταντινούπολις Konstantinoúpolis or Κωνσταντινούπολη Konstantinoúpoli, Latin Constantinopolis; Ottoman Turkish قسطنطینية, Kostantiniyye, was founded by the Roman Emperor Constantine I The Great (272–337 AD) in 324 on the site of an already-existing city, Byzantium, in greek Βυζάντιον-Byzántion which was settled in the early days of Greek colonial expansion, around 671–662 BC.

The site lay astride the land route from Europe to Asia and the seaway from the Black Sea to the Mediterranean, and had in the Golden Horn an excellent and spacious harbour.
Constantinople was built over 6 years, and consecrated on 11 May 330 AD.

Photo,
An artistic reconstruction of Constantinople in Late Antiquity.

Long live Satan…


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Cum arată islamizarea Europei: 640 de autobuze cu ”Glorie lui Allah” circulă prin Londra unde primarul este musulman

Cei care au salutat alegerea unui primar musulman la Londra pot vedea acum și efectele: autobuzele din oraș vor circula cu inscripția ”Glorie lui Allah”. De Crăciunul trecut însă, un videoclip cu Crăciunul a fost interzis în cinematografele din Marea Britanie ca să nu-i ofenseze pe musulmani.
Frați români, islamizarea Europei e o realitate, nu e invenția mea. Iar cei care vă zic să stați liniștiți că nu e nicio problemă că ni se face o mega moschee la București sau că primim imigranți musulmani vă mint pe față!
Votați Partidul România Unită, singurul partid naționalist, singurul partid anti-imigrație, dacă vreți să salvăm România de islamizarea care a cuprins Europa!

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My birds on the wire today no.3


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My Chakra Today no.2


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My birds on the wire today no.2


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My pot with flowers today No.2


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My Duck today No.1


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My Chakra Today no.1


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My birds on the wire today no.1


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My pot with flowers today No.2


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My pot with flowers today No.1


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Martin pescatore – Kingfisher Visit my page : https://www.facebook.com/carlo.galliani.58


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Martin pescatore – Kingfisher
Visit my page : https://www.facebook.com/carlo.galliani.58

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Primul simpton al prostiei este…


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Hi, it’s me GEORGE W. “AKA THE IDIOT” WHO….HIHIHIHI…:


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