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MHC sets match as closely as possible. Otherwise, the recipient's T cells will likely attack the transplant, leading to graft rejection. To find good matches, tissue typing is usually done on white blood cells, or leukocytes. In this case, the |
MHC-self-markers are called human leukocyte antigens, or HLA. Each cell has a double set of six major HLA markers, HLA-A, B, and C, and three types of HLA-D. Since each of these antigens exists, in different individuals, in as many |
as 20 varieties, the number of possible HLA types is about 10,000. The genes that encode the HLA antigens are located on chromosome 6. A child in the womb carries foreign antigens from the father as well as immunologically compatible |
self-antigens from the mother. One might expect this condition to trigger a graft rejection, but it does not because the uterus is an "immunologically privileged" site where immune responses are somehow subdued. Immunity and Cancer When normal cells turn into |
cancer cells, some of the antigens on their surface change. These cells, like many body cells, constantly shed bits of protein from their surface into the circulatory system. Often, tumor antigens are among the shed proteins. These shed antigens prompt |
action from immune defenders, including cytotoxic T cells, natural killer cells, and macrophages. According to one theory, patrolling cells of the immune system provide continuous bodywide surveillance, catching and eliminating cells that undergo malignant transformation. Tumors develop when this immune |
surveillance breaks down or is overwhelmed. A new approach to cancer therapy uses antibodies that have been specially made to recognize specific cancers. When coupled with natural toxins, drugs, or radioactive substances, the antibodies seek out their target cancer cells |
and deliver their lethal load. Alternatively, toxins can be linked to a lymphokine and routed to cells equipped with receptors for the lymphokine. Dendritic Cells That Attack Cancer Another approach to cancer therapy takes advantage of the normal role of |
the dendritic cell as an immune educator. Dendritic cells grab antigens from viruses, bacteria, or other organisms and wave them at T cells to recruit their help in an initial T cell immune response. This works well against foreign cells |
that enter the body, but cancer cells often evade the self/non-self detection system. By modifying dendritic cells, researchers are able to trigger a special kind of autoimmune response that includes a T cell attack of the cancer cells. Because a |
cancer antigen alone is not enough to rally the immune troops, scientists first fuse a cytokine to a tumor antigen with the hope that this will send a strong antigenic signal. Next, they grow a patient's dendritic cells in the |
incubator and let them take up this fused cytokine-tumor antigen. This enables the dendritic cells to mature and eventually display the same tumor antigens as appear on the patient's cancer cells. When these special mature dendritic cells are given back |
to the patient, they wave their newly acquired tumor antigens at the patient's immune system, and those T cells that can respond mount an attack on the patient's cancer cells. The Immune System and the Nervous System Biological links between |
the immune system and the central nervous system exist at several levels. Hormones and other chemicals such as neuropeptides, which convey messages among nerve cells, have been found also to "speak" to cells of the immune system--and some immune cells |
even manufacture typical neuropeptides. In addition, networks of nerve fibers have been found to connect directly to the lymphoid organs. The picture that is emerging is of closely interlocked systems facilitating a two-way flow of information. Immune cells, it has |
been suggested, may function in a sensory capacity, detecting the arrival of foreign invaders and relaying chemical signals to alert the brain. The brain, for its part, may send signals that guide the traffic of cells through the lymphoid organs. |
A hybridoma is a hybrid cell produced by injecting a specific antigen into a mouse, collecting an antibody-producing cell from the mouse's spleen, and fusing it with a long-lived cancerous immune cell called a myeloma cell. Individual hybridoma cells are |
cloned and tested to find those that produce the desired antibody. Their many identical daughter clones will secrete, over a long period of time, millions of identical copies of made-to-order "monoclonal" antibodies. Thanks to hybridoma technology, scientists are now able |
to make large quantities of specific antibodies. Genetic engineering allows scientists to pluck genes--segments of DNA--from one type of organism and to combine them with genes of a second organism. In this way, relatively simple organisms such as bacteria or |
yeast can be induced to make quantities of human proteins, including interferons and interleukins. They can also manufacture proteins from infectious agents, such as the hepatitis virus or the AIDS virus, for use in vaccines. The SCID-hu Mouse The SCID |
mouse, which lacks a functioning immune system of its own, is helpless to fight infection or reject transplanted tissue. By transplanting immature human immune tissues and/or immune cells into these mice, scientists have created an in vivo model that promises |
Locust Care Sheet Locust are probably the largest type of insect that you will use as livefood. Adults measure up to 8cm and are a yellow colour with darker brown/purple patches. They are popular for their large gut content which means they are highly nutritious feeders but are somewhat expensive compared to other fopt... |
They are quite pleasant to have around and will not try to bite like a cricket would. Locust are often portrayed as a swarm insect that destroys crops and eats everything in their path. In fact, they are lower down the pecking order than crickets so the two should never be mixed, unless the aim is to feed the crickets. |
However, they do eat a lot and grow fairly quickly. Only adult locust have wings that are able to give them flight. All locust have wings but only at the 5th and final moult a locust develops flying wings and are capable of flight over short distances. Locust have amazing claws they can hold onto and climb just about a... |
including glass. They tend to hang upside down while shedding so their good grip comes is readily employed. Housing and Heating Housing locust is just like housing crickets, you will want to put them in the biggest tub you can find (of course glass is fine), as long as it is sufficiently deep to deter any would-be esca... |
important to locust so make sure the lid is perforated with holes, you can do this with a drill or a soldering iron. As locust prefer to perch a substrate really is not necessary, so a simple stack of egg crates does the trick and also provides hiding places. For water, provide a dish of damp kitchen roll, this prevent... |
drowning and is easily changed when it gets dirty. When it comes to cleaning time after a week or two, there are several options. You are probably best lifting out the hides slowly and transferring them to another tub while working around the rest of the locust while cleaning the tub. Shake the locust off the egg crate... |
them away, swap them with clean ones and you have a nice clean tub of locust. Alternatively you can use all the locust then throw the whole lot away before purchasing a fresh batch. As for temperature, locusts like a temperature of 25-33°C (77-91.4°F) and a dry atmosphere which will prevent fungal infections. Feeding... |
crickets. They need to be provided with a good supply of dry foods, "bug grub" is an insect feeder that has a mixture of ingredients designed to be fed to insects so that they have a good gut content and provide ample nutrients to your pets. Alternative foods can be used such as bran, weetabix, digestives and bread. Fr... |
as grapes, apples or vegetables such as potatoes, tomatoes and cabbage provide extra vitamins and moisture. If moist foods are available on a regular basis then a water dish is not really needed. Breeding Locust Temperature and humidity are important in breeding. Eggs are laid in a 4 inch deep dish filled with silver o... |
tub as such. The sand should be kept moist but not too wet so it looks soggy. The female locust will position herself over the sand dish and push her down and deposit up to 200 eggs. Hoppers will emerge after 10 - 12 days. The hoppers will go through 5 instar molting before becoming adult locust. |
Drive by a local wetland on an early spring evening, and if you're lucky you'll hear a harbinger of the changing season - the clear chirping chorus of tiny frogs known as spring peepers, classified by biologists as Pseudacris crucifer. |
Few themes in literature are more alluring than the lost world. Places such as Atlantis, Shangri-La, Conan Doyle's "Lost World", and now the bestselling "The Lost City of Z" conjure up images of strange landscapes, exotic civilizations and hidden treasures. |
Ecologists study phenology, which is the orderly progression of seasonal events in nature, such as the springtime arrival of migrating birds, the first chorus of spring peepers in vernal pools, and the development of tree colors each autumn Despite the |
fact 60 percent of us in Dutchess County drink groundwater every day, and all of us eat food irrigated by ground water, very few people know where it comes from, where it goes, or that groundwater is full of life |
Thankfully, the argument about the reality of global climate change seems finished. The majority of the public now joins the consensus of climate scientists, who have furnished compelling proof that the planet is warming and that humans are at least |
partly to blame. What if our children could recognize the birds, plants and insects in their backyards as well as they know the brands of shoes on their feet or the secret weapons they need to get to the next |
level in a video game? If you ever saw "Star Wars," you'll remember the trash compactor scene: Trying to escape from the Imperials, Luke and his friends duck into what turns out to be a trash compactor, where things go |
from bad to worse. New York state is taking an essential step to deal with invasive species, one of the most damaging and difficult environmental problems of our time, by proposing to limit the importation of ballast water into the |
state. Dengue (pronounced DEN-ghee) fever is caused by a virus spread by mosquitoes. It was formerly called "break-bone fever" because it causes excruciating pain to the muscles and joints of its human victims. We tend to think of nature as |
having reliable patterns; the leaves turn color each autumn, seasonal birds come and go. But there are also examples of sudden, unexpected changes in the environment around us. Specific trails and roads on our 2,000 acre research campus have been |
In the interior of central Africa the first Catholic missions were established by Cardinal Lavigerie's White Fathers in 1879. In Uganda some progress was made under the not unfriendly local ruler, Mtesa; but his successor, Mwanga, determined to root out Christianity among his people, especially after a Catholic subject... |
massacre of the Protestant missionary James Hannington and his caravan. Mwanga was addicted to unnatural vice and his anger against Christianity, already kindled by ambitious officers who played on his fears, was kept alight by the refusal of Christian boys in his service to minister to his wickedness. himself was the ... |
on November 15, 1885, had him beheaded. To the chieftain's astonishment the Christians were not cowed by this sudden outrage, and in May of the following year the storm burst. When he called for a young 'page' called Mwafu, Mwanga learned that he had been receiving religious instruction from another page, St. Denis Seb... |
king thrust a spear through his throat. That night guards were posted round the royal residence to prevent anyone from escaping. Charles Lwanga, who had succeeded Joseph Mkasa in charge of the 'pages', secretly baptized four of them who were catechumens; among them St Kizito, a boy of thirteen whom Lwanga had repeatedl... |
Next morning the pages were all drawn up before Mwanga, and Christians were ordered to separate themselves from the rest: led by Lwanga and Kizito, the oldest and youngest, they did so—fifteen young men, all under twenty-five years of age. They were joined by two others already under arrest and by two soldiers. Mwanga ... |
remain Christians. "Till death!" came the response. "Then put them to death!" The appointed place of execution, Namugongo, was thirty-seven miles away, and the convoy set out at once. Three of the youths were killed on the road; the others underwent a cruel imprisonment of seven days at Namugongo while a huge pyre was ... |
3, 1886, they were brought out, stripped of their clothing, bound, and each wrapped in a mat of reed: the living faggots were laid on the pyre (one boy, St Mbaga, was first killed by a blow on the neck by order of his father who was the chief executioner), and it was set alight. The persecution spread and Protestants |
as well as Catholics gave their lives rather than deny Christ. A leader among the confessors was St Matthias Murumba, who was put to death with revolting cruelty; he was a middle-aged man, assistant judge to the provincial chief, who first heard of Jesus Christ from Protestant missionaries and later was baptized by Fat... |
was beheaded, was St Andrew Kagwa, chief of Kigowa, who had been the instrument of his wife's conversion and had gathered a large body of catechumens round him. This Andrew together with Charles Lwanga and Matthias Murumba and nineteen others (seventeen of the total being young royal servants) were solemnly beatified i... |
White Fathers were expelled from the country, the new Christians carried on their work, translating and printing the catechism into their nativel language and giving secret instruction on the faith. Without priests, liturgy, and sacraments their faith, intelligence, courage, and wisdom kept the Catholic Church alive an... |
St. Bernard of Menthon Born in 923, probably in the castle Menthon near Annecy, in Savoy ; died at Novara, 1008. He was descended from a rich, noble family and received a thorough education. He refused to enter an honorable marriage proposed by his father and decided to devote himself to the service of the Church. Plac... |
direction of Peter, Archdeacon of Aosta, under whose guidance he rapidly progressed, Bernard was ordained priest and on account of his learning and virtue was made Archdeacon of Aosta (966), having charge of the government of the diocese under the bishop. Seeing the ignorance and idolatry still prevailing among the peo... |
their conversion. For forty two years he continued to preach the Gospel to these people and carried the light of faith even into many cantons of Lombardy, effecting numerous conversions and working many miracles. For another reason, however, Bernard's name will forever be famous in history. Since the most ancient times... |
from the valley of Aosta to the Swiss canton of Valais, over what is now the pass of the Great St. Bernard. This pass is covered with perpetual snow from seven to eight feet deep, and drifts sometimes accumulate to the height of forty feet. Though the pass was extremely dangerous, especially in the springtime on accoun... |
it was often used by French and German pilgrims on their way to Rome. For the convenience and protection of travelers St. Bernard founded a monastery and hospice at the highest point of the pass, 8,000 feet above sea-level, in the year 962. A few years later he established another hospice on the Little St. Bernard, a m... |
Graian Alps, 7,076 feet above sea-level. Both were placed in charge of Augustinian monks after pontifical approval had been obtained by him during a visit to Rome. These hospices are renowned for the generous hospitality extended to all travelers over the Great and Little St. Bernard, so called in honor of the founder ... |
of the year, but especially during heavy snow-storms, the heroic monks accompanied by their well-trained dogs, go out in search of victims who may have succumbed to the severity of the weather. They offer food, clothing, and shelter to the unfortunate travelers and take care of the dead. They depend on gifts and collec... |
consists of about forty members, the majority of whom live at the hospice while some have charge of neighboring parishes. The last act of St. Bernard's life was the reconciliation of two noblemen whose strife threatened a fatal issue. He was interred in the cloister of St. Lawrence. Venerated as a saint from the twelft... |
Piedmont (Aosta, Novara, Brescia ), he was not canonized until 1681, by Innocent XI. His feast is celebrated on the 15th of June. More Catholic Encyclopedia Browse Encyclopedia by Alphabet The Catholic Encyclopedia is the most comprehensive resource on Catholic teaching, history, and information ever gathered in all of... |
hardcopy volumes. Designed to present its readers with the full body of Catholic teaching, the Encyclopedia contains not only precise statements of what the Church has defined, but also an impartial record of different views of acknowledged authority on all disputed questions, national, political or factional. In the d... |
employed, and the results of the latest research in theology, philosophy, history, apologetics, archaeology, and other sciences are given careful consideration. No one who is interested in human history, past and present, can ignore the Catholic Church, either as an institution which has been the central figure in the ... |
religious, literary, scientific, social and political, or as an existing power whose influence and activity extend to every part of the globe. In the past century the Church has grown both extensively and intensively among English-speaking peoples. Their living interests demand that they should have the means of inform... |
not, affects their fortunes and their destiny. Browse the Catholic Encyclopedia by Topic Copyright © Catholic Encyclopedia. Robert Appleton Company New York, NY. Volume 1: 1907; Volume 2: 1907; Volume 3: 1908; Volume 4: 1908; Volume 5: 1909; Volume 6: 1909; Volume 7: 1910; Volume 8: 1910; Volume 9: 1910; Volume 10: 191... |
Computer Models How Buds Grow Into Leaves Posted on March 02, 2012 at 08:24:51 am "A bud does not grow in all directions at the same rate," said Samantha Fox from the John Innes Centre on Norwich Research Park. "Otherwise |
leaves would be domed like a bud, not flat with a pointed tip." By creating a computer model to grow a virtual leaf, the BBSRC-funded scientists managed to discover simple rules of leaf growth. -ADVERTISEMENT-Similar to the way a compass |
works, plant cells have an inbuilt orientation system. Instead of a magnetic field, the cells have molecular signals to guide the axis on which they grow. As plant tissues deform during growth, the orientation and axis changes. The molecular signals |
become patterned from an early stage within the bud, helping the leaf shape to emerge. The researchers filmed a growing Arabidopsis leaf, a relative of oil seed rape, to help create a model which could simulate the growing process. They |
were able to film individual cells and track them as the plant grew. It was also important to unpick the workings behind the visual changes and to test them in normal and mutant plants. "The model is not just based |
on drawings of leaf shape at different stages," said Professor Enrico Coen. "To accurately recreate dynamic growth from bud to leaf, we had to establish the mathematical rules governing how leaf shapes are formed." With this knowledge programmed into the |
model, developed in collaboration with Professor Andrew Bangham's team at the University of East Anglia, it can run independently to build a virtual but realistic leaf. Professor Douglas Kell, Chief Executive of BBSRC said: "This exciting research highlights the potential |
of using computer and mathematical models for biological research to help us tackle complex questions and make predictions for the future. Computational modelling can give us a deeper and more rapid understanding of the biological systems that are vital to |
life on earth." The model could now be used to help identify the genes that control leaf shape and whether different genes are behind different shapes. "This simple model could account for the basic development and growth of all leaf |
how to keep your child healthy? Need symptom or treatment information? Look under the symptom or disease headings below. information on health topics that do not concern infectious diseases, check Health Topic: Infants and Children in the CDC Health Topics A-Z pages. and major sites Ounce of Prevention Keeps the Germs ... |
infectious disease. Disinfecting, vaccinating, safe pet keeping... Text and video With swimming such a popular activity, you should know how to protect you and your family from recreational water illnesses (RWIs) and help stop germs from getting into the water where you swim in the first place. Fact sheets and printabl... |
we do not see patients and are unable to diagnose your illness, provide treatment, prescribe medication, or refer you to specialists. you have a medical emergency, contacting CDC is not the proper way to get immediate help. Instead, please contact your health care provider or go to the nearest emergency room. If you ar... |
Irish Druids And Old Irish EARLY RELIGIONS OF THE One of the most philosophical statements from Max Müller is to this effect: "Whatever we know of early religion, we always see that it presupposes vast periods of an earlier development." This is exhibited in the history of all peoples that |
have progressed in civilization, though we may have to travel far back on the track of history to notice transformations of thought or belief. When the late Dr. Birch told us that a pyramid, several hundreds of years older than the Great Pyramid, contained the name of Osiris, we knew |
that at least the Osirian part of Egyptian mythology was honoured some six or seven thousand years ago What the earlier development of religion there was, or how the conception of a dying and risen Osiris arose, at so remote a period, may well excite our wonder. Professor Jebb writes--"There |
was a time when they (early man) began to speak of the natural powers as persons, and yet had not forgotten that they were really natural, powers, and that the persons' names were merely signs? Yet this goes on the assumption that religion--or rather dogmas thereof--sprang from reflections upon natural |
phenomena. In this way, the French author of Sirius satisfied himself, particularly on philological grounds, that the idea, of God sprang from an association with thunder and the barking of a dog. We are assured by Max Müller, that religion is a word that has changed from century to century, |
and that "the word rose to the surface thousands of years ago." Taking religion to imply an inward feeling of reverence toward the unseen, and a desire to act in obedience to the inward law of right, religion has existed as long as humanity itself. What is commonly assumed by |
the word religion, by writers in general, is dogma or belief. The importance of this subject was well put forth by the great Sanscrit scholar in the phrase, "The real history of man is the history of religion." This conviction lends interest and weight to any investigations into the ancient |
religion of Ireland; though Plowden held that" few histories are so charged with fables as the annals of Ireland." It was Herder who finely said, "Our earth owes the seeds of all higher culture to a religious tradition, whether literary or oral." In proportion as the so-called supernatural gained an |
ascendancy, so was man really advancing from the materialism and brutishness of savagedom. Lecky notes "the disposition of man in certain stages of society towards the miraculous." But was Buckle quite correct in maintaining that "all nature conspired to increase the authority of the imaginative faculties, and weaken t... |
of the reasoning ones"? It is not to be forgotten in our inquiry that, as faiths rose in the East, science has exerted its force in the West. Fetishism can hardly be regarded as the origin of religion. As to those writers who see in the former the deification of |
natural objects, Max Müller remarks, "They might as well speak of primitive men mummifying their dead bodies Before they had wax to embalm them with." Myth has been styled the basis of religion not less than of history; but how was it begotten? Butler, in English, Irish, and Scottish Churches, |
writes-- "To separate the fabulous from the probable, and the probable from the true, will require no ordinary share of penetration and persevering industry." We have certainly to remember, as one has said, that "mythic history, mythic theology, mythic science, are alike records, not of facts, but beliefs." Andrew Lang |
properly calls our attention to language, as embodying thought,, being so liable to misconception and misinterpretation. Names, connected with myths, have been so variously read and explained by scholars, that outsiders may well be puzzled. How rapidly a myth grows, and is greedily accepted, because of the wish it may |
be true, is exemplified in the pretty story, immortalized by music, of Jessie of Lucknow, who, in the siege, heard her deliverers, in the remote distance, playing "The Campbells are coming." There never was, however, a Jessie Brown there at that time; and, as one adds, Jessie has herself "been |
sent to join William Tell and the other dethroned gods and In the Hibbert Lectures, Professor Rhys observes, "The Greek myth, which distressed the thoughtful and pious minds, like that of Socrates, was a survival, like the other scandalous tales about the gods, from the time when the ancestors of |
the Greeks were savages." May it not rather have been derived by Homer, through the trading Phœnicians, from the older mythologies of India and Egypt, with altered names and scenes to suit the poet's day and clime? It would scarcely do to say with Thierry, "In legend alone rests real |
history--for legend is living tradition, and three times out of four it is truer than what we call History." According to Froude, "Legends grew as nursery tales grow now.--There is reason to believe that religious theogonies and heroic tales of every nation that has left a record of itself, are |
but practical accounts of the first impressions produced upon mankind by the phenomena of day and night, morning and evening, winter and summer." Such may be a partial explanation; but it may be also assumed that they were placed on record by the scientific holders of esoteric wisdom, as problems |
or studies for elucidation by disciples. The anthropological works of Sir John Lubbock and Dr. Tylor can be consulted with profit upon this subject of primitive religious thought. Hayes O'Grady brings us back to Ireland, saying, "Who shall thoroughly discern the truth from the fiction with which it is everywhere |
entwined, and in many places altogether overlaid?--There was at one time a vast amount of zeal, ingenuity, and research expended on the elucidation and confirming of these fables; which, if properly applied, would have done Irish history and archaeology good service, instead of making their very names synonymous among ... |
with fancy and delusion." After this we can proceed with the Irish legends and myths, the introduction to this inquiry being a direction to the current superstitions of the race. |
You have to like the attitude of Thomas Henning (Max-Planck-Institut für Astronomie). The scientist is a member of a team of astronomers whose recent work on planet formation around TW Hydrae was announced this afternoon. Their work used data from |
ESA’s Herschel space observatory, which has the sensitivity at the needed wavelengths for scanning TW Hydrae’s protoplanetary disk, along with the capability of taking spectra for the telltale molecules they were looking for. But getting observing time on a mission |
like Herschel is not easy and funding committees expect results, a fact that didn’t daunt the researcher. Says Henning, “If there’s no chance your project can fail, you’re probably not doing very interesting science. TW Hydrae is a good example |
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