Showing posts with label Bio science. Show all posts
Showing posts with label Bio science. Show all posts

Chemistry I: atom and molecule

Atoms

Most of the Universe consists of matter and energy. Energy is the capacity to do work. Matter has mass and occupies space. All matter is composed of basic elements that cannot be broken down to substances with different chemical or physical properties. Elements are substances consisting of one type of atom, for example Carbon atoms make up diamond, and also graphite. Pure (24K) gold is composed of only one type of atom, gold atoms. Atoms are the smallest particle into which an element can be divided. The ancient Greek philosophers developed the concept of the atom, although they considered it the fundamental particle that could not be broken down. Since the work of Enrico Fermi and his colleagues, we now know that the atom is divisible, often releasing tremendous energies as in nuclear explosions or (in a controlled fashion in) thermonuclear power plants.
Subatomic particles were discovered during the 1800s. For our purposes we will concentrate only on three of them, summarized in Table 1. The proton is located in the center (or nucleus) of an atom, each atom has at least one proton. Protons have a charge of +1, and a mass of approximately 1 atomic mass unit (amu). Elements differ from each other in the number of protons they have, e.g. Hydrogen has 1 proton; Helium has 2.
The neutron also is located in the atomic nucleus (except in Hydrogen). The neutron has no charge, and a mass of slightly over 1 amu. Some scientists propose the neutron is made up of a proton and electron-like particle.
The electron is a very small particle located outside the nucleus. Because they move at speeds near the speed of light the precise location of electrons is hard to pin down. Electrons occupy orbitals, or areas where they have a high statistical probability of occurring. The charge on an electron is -1. Its mass is negligible (approximately 1800 electrons are needed to equal the mass of one proton).
Table 1. Subatomic particles of use in biology.
Name
Charge
Location
Mass
Proton
+1
atomic nucleus
1.6726 X 10-27 kg
Neutron
0
atomic nucleus
1.6750 X 10-27 kg
Electron
-1
electron orbital
9.1095 X 10-31 kg
The atomic number is the number of protons an atom has. It is characteristic and unique for each element. The atomic mass (also referred to as the atomic weight) is the number of protons and neutrons in an atom. Atoms of an element that have differing numbers of neutrons (but a constant atomic number) are termed isotopes. Isotopes, shown in Figure 1 and Figure 2, can be used to determine the diet of ancient peoples by determining proportions of isotopes in mummified or fossilized human tissues. Biochemical pathways can be deciphered by using isotopic tracers. The age of fossils and artifacts can be determined by using radioactive isotopes, either directly on the fossil (if it is young enough) or on the rocks that surround the fossil (for older fossils like dinosaurs). Isotopes are also the source of radiation used in medical diagnostic and treatment procedures.
Figure 1. Note that each of these isotopes of hydrogen has only one proton. Isotopes differ from each other in the number of neutrons, not in the number of protons. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Some isotopes are radioisotopes, which spontaneously decay, releasing radioactivity. Other isotopes are stable. Examples of radioisotopes are Carbon-14 (symbol 14C), and deuterium (also known as Hydrogen-2; 2H). Stable isotopes are 12C and 1H.
Figure 2. Carbon has three isotopes, of which carbon-12 and carbon-14 are the most well known. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
The Periodic Table of the Elements, a version of which is shown in Figure 3, provides a great deal of information about various elements. An on-line Periodic Table is available by clicking here,
Figure 3. The Periodic Table of the Elements. Each Roman numeraled column on the label (at least the ones ending in A) tells us how many electrons are in the outer shell of the atom. Each numbered row on the table tells us how many electron shells an atom has. Thus, Hydrogen, in column IA, row 1 has one electron in one shell. Phosphorous in column VA, row 3 has 5 electrons in its outer shell, and has three shells in total. Image from James K. Hardy's chemistry site at the University of Akron.

Electrons and energy

Electrons, because they move so fast (approximately at the speed of light), seem to straddle the fence separating energy from matter. Albert Einstein developed his famous E=mc2 equation relating matter and energy over a century ago. Because of his (and others) work, we think of electrons both as particles of matter (having mass is a property of matter) and as units (or quanta) of energy. When subjected to energy, electrons will acquire some of that energy, as shown in Figure 4.
Figure 4. Excitation of an electron by energy, causing the electron to "jump" to another electron (energy) level known as the excited state. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
An orbital is also an area of space in which an electron will be found 90% of the time. Orbitals have a variety of shapes. Each orbital has a characteristic energy state and a characteristic shape. The s orbital is spherical. Since each orbital can hold a maximum of two electrons, atomic numbers above 2 must fill the other orbitals. The px, py, and pz orbitals are dumbbell shaped, along the x, y, and z axes respectively. These orbital shapes are shown in Figure 5.
Energy levels (also referred to as electron shells) are located a certain "distance" from the nucleus. The major energy levels into which electrons fit, are (from the nucleus outward) K, L, M, and N. Sometimes these are numbered, with electron configurations being: 1s22s22p1, (where the first shell K is indicated with the number 1, the second shell L with the number 2, etc.). This nomenclature tells us that for the atom mentioned in this paragraph, the first energy level (shell) has two electrons in its s orbital (the only orbital it can have), and second energy level has a maximum of two electrons in its s orbital, plus one electron in its p orbital.
Figure 5. Geometry of orbitals. S-orbitals are spherical, p-orbitals are shaped like a dumbbell or figure 8. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Chemical Bonding

During the nineteenth century, chemists arranged the then-known elements according to chemical bonding, recognizing that one group (the furthermost right column on the Periodic Table, referred to as the Inert Gases or Noble Gases) tended to occur in elemental form (in other words, not in a molecule with other elements). It was later determined that this group had outer electron shells containing two (as in the case of Helium) or eight (Neon, Xenon, Radon, Krypton, etc.) electrons.
As a general rule, for the atoms we are likely to encounter in biological systems, atoms tend to gain or lose their outer electrons to achieve a Noble Gas outer electron shell configuration of two or eight electrons. The number of electrons that are gained or lost is characteristic for each element, and ultimately determines the number and types of chemical bonds atoms of that element can form. Atomic diagrams for several atoms are shown in Figure 6.
Figure 6. Atomic diagrams illustrating the filling of the outer electron shells. Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Ionic bonds are formed when atoms become ions by gaining or losing electrons. Chlorine is in a group of elements having seven electrons in their outer shells (see Figure 6). Members of this group tend to gain one electron, acquiring a charge of -1. Sodium is in another group with elements having one electron in their outer shells. Members of this group tend to lose that outer electron, acquiring a charge of +1. Oppositely charged ions are attracted to each other, thus Cl- (the symbolic representation of the chloride ion) and Na+ (the symbol for the sodium ion, using the Greek word natrium) form an ionic bond, becoming the molecule sodium chloride, shown in Figure 7. Ionic bonds generally form between elements in Group I (having one electron in their outer shell) and Group VIIa (having seven electrons in their outer shell). Such bonds are relatively weak, and tend to disassociate in water, producing solutions that have both Na and Cl ions.
Figure 7. TOP: Formation of a crystal of sodium chloride. Each positively charged sodium ion is surropunded by six negatively charged chloride ions; likewise each negatively charged chloride ion is surrounded by six positively charged sodium ions. The overall effect is electrical neutrality. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission. BOTTOM: Table Salt Crystal (SEM x625). This image is copyright Dennis Kunkel at www.DennisKunkel.com, used with permission.
Covalent bonds form when atoms share electrons. Since electrons move very fast they can be shared, effectively filling or emptying the outer shells of the atoms involved in the bond. Such bonds are referred to as electron-sharing bonds. An analogy can be made to child custody: the children are like electrons, and tend to spend some time with one parent and the rest of their time with the other parent. In a covalent bond, the electron clouds surrounding the atomic nuclei overlap, as shown in Figure 8.
Figure 8. Formation of a covalent bond between two Hydrogen atoims. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Carbon (C) is in Group IVa, meaning it has four electrons in its outer shell. Thus to become a "happy atom", Carbon can either gain or lose four electrons. By sharing the electrons with other atoms, Carbon can become a happy atom,. alternately filling and emptying its outer shell, as with the four hydrogens shown in Figure 9.
Figure 9. Formation of covalent bonds in methane. Carbon needs to share four electrons, in effect it has four slots. Each hydrogen provides an electron to each of these slots. At the same time each hydrogen needs to fill one slot, which is done by sharing an electron with the carbon. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
The molecule methane (chemical formula CH4) has four covalent bonds, one between Carbon and each of the four Hydrogens. Carbon contributes an electron, and Hydrogen contributes an electron. The sharing of a single electron pair is termed a single bond. When two pairs of electrons are shared, a double bond results, as in carbon dioxide. Triple bonds are known, wherein three pairs (six electrons total) are shared as in acetylene gas or nitrogen gas. The types of covalent bonds are shown in Figure 10.
Figure 10. Ways of representing covalent bonds. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Sometimes electrons tend to spend more time with one atom in the bond than with the other. In such cases a polar covalent bond develops. Water (H2O) is an example. Since the electrons spend so much time with the oxygen (oxygen having a greater electronegativity, or electron affinity) that end of the molecule acquires a slightly negative charge. Conversely, the loss of the electrons from the hydrogen end leaves a slightly positive charge. The water molecule is thus polar, having positive and negative sides.
Hydrogen bonds, as shown in Figure 11, result from the weak electrical attraction between the positive end of one molecule and the negative end of another. Individually these bonds are very weak, although taken in a large enough quantity, the result is strong enough to hold molecules together or in a three-dimensional shape.
Figure 11. TOP: Formation of a hydrogen bond between the hydrogen side of one water molecule and the oxygen side of another water molecule. BOTTOM: The presence of polar areas in the amino acids that makeup a protein allows for hydrogen bonds to form, giving the molecule a three-dimensional shape that is often vital to that protein's proper functioning. Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Chemical reactions and molecules

Molecules are compounds in which the elements are in definite, fixed ratios, as seen in Figure 12. Those atoms are held together usually by one of the three types of chemical bonds discussed above. For example: water, glucose, ATP. Mixtures are compounds with variable formulas/ratios of their components. For example: soil. Molecular formulas are an expression in the simplest whole-number terms of the composition of a substance. For example, the sugar glucose has 6 Carbons, 12 hydrogens, and 6 oxygens per repeating structural unit. The formula is written C6H12O6.
Figure 12. Determination of molecular weights by addition of the weights of the atoms that make up the molecule. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Chemical reactions occur in nature, and some also can be performed in a laboratory setting. One such reaction is diagrammed in Figure 13. Chemical equations are linear representations of how these reactions occur. Combination reactions occur when two separate reactants are bonded together, e.g. A + B -----> AB. Disassociation reactions occur when a compound is broken into two products, e.g. AB -----> A + B.
Figure 13. Diagram of a chemical reaction: the combustion of propane with oxygen, resulting in carbon dioxide, water, and energy (as heat and light). This chemical reaction takes place in a camping stove as well as in certain welding torches. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Biological systems, while unique to each species, are based on the chemical bonding properties of carbon. Major organic chemicals (those associated with or formed by the actions of living things) usually include some ratios of the following elements: C, H, N, O, P, S.
READ MORE - Chemistry I: atom and molecule

Hypoallergenic Dogs Don't Have Lower Household Allergen Levels Than Other Dogs

That's the cessation of a abstraction by Henry Ford Hospital advisers who approved to evaluate whether hypoallergenic canines accept a lower dog allergen in the house than added canines. Hypoallergenic canines are believed to aftermath beneath acrimony and saliva and afford beneath fur. Contrary to popular belief, so-called hypoallergenic dogs do not have lower household allergen levels than other dogs.

The allegation are to be appear online this ages in the American Journal of Rhinology and Allergy.

"Based on antecedent abhorrence studies conducted actuality at Henry Ford, acknowledgement to a dog aboriginal in activity provides aegis adjoin dog abhorrence development. But the abstraction that you can buy a assertive brand of dog and anticipate it will account beneath abhorrence issues for a being already dog-allergic is not borne out by our study."

"We start no correct base to the affirmation hypoallergenic canines accept beneath allergen," says Christine Cole Johnson, Ph.D., MPH, armchair of Henry Ford's Department of Public Health Sciences and chief columnist of the study.

This is believed to be the aboriginal time advisers abstinent ecology allergen associated with hypoallergenic canines. Antecedent studies analyzed beard samples from alone a scattering of canines in a kid cardinal of breeds.

Henry Ford advisers analyzed dust samples calm from 173 homes ages afterwards a bairn was brought home. The dust samples were calm from the carpeting or attic in the baby's bedchamber and analyzed for the dog allergen Can f one. Alone homes with dog were complex in the study. Sixty dog breeds were complex in the study, 11 of which are advised hypoallergenic canines.

Researchers start that the schemes yielded no cogent differences in allergen levels amid hypoallergenic canines and non-hypoallergenic canines. In homes area the dog was not accustomed in the baby's bedroom, the allergen akin for hypoallergenic canines was not very college compared to allergen levels of non-hypoallergenic canines.

Based on available web armpit claims of hypoallergenic breeds, canines were classified as hypoallergenic application of "schemes" based on their brand for comparing allergen levels. Technique A compared blood hypoallergenic canines to blood non-hypoallergenic dogs; Technique B compared blood and alloyed brand canines with at atomic hypoallergenic ancestor to blood non-hypoallergenic dogs; Technique C compared blood and alloyed brand canines with at atomic hypoallergenic ancestor to blood and alloyed brand canines with no accepted hypoallergenic component; Technique D compared alone blood canines articular as hypoallergenic by the American Kennel Club to all added canines.

While advisers accustomed limitations in their abstraction -- the bulk of time the dog spent in the baby's bedchamber was not recorded and the admeasurement of its sample did not acquiesce stunning at specific breeds -- they say parents ought to not await on dog breeds classified as hypoallergenic.
READ MORE - Hypoallergenic Dogs Don't Have Lower Household Allergen Levels Than Other Dogs

Genetic Code

The abiogenetic cipher is the set of rules by which advice encoded in abiogenetic actual (DNA or RNA sequences) is translated into proteins (amino acerbic sequences) by active cells.

Because the all-inclusive majority of genes are encoded with absolutely the aforementioned code, this correct cipher is usually often called the approved or accepted abiogenetic code, or artlessly the abiogenetic code, admitting in actuality there's abounding alternative codes; thus, the approved abiogenetic cipher is not universal.

Specifically, the cipher defines a mapping amid tri-nucleotide sequences alleged codons and amino acids; every leash of nucleotides in a nucleic acerbic manipulation specifies a distinct amino acid.

The allocation of the genome that codes for a protein or an RNA is often called a gene.

For example, in humans, protein amalgam in mitochondria depends on a abiogenetic cipher that varies from the approved code. The genome of an animal is inscribed in DNA, or in some bacilli RNA.

Those genes that cipher for proteins are composed of tri-nucleotide units alleged codons, anniversary coding for a distinct amino acid.

Each nucleotide sub-unit consists of a phosphate, deoxyribose amoroso and of the four nitrogenous nucleotide bases.

The purine bases adenine (A) and guanine (G) are beyond and abide of ambrosial rings.

The pyrimidine bases cytosine (C) and thymine (T) are abate and abide of alone ambrosial ring.

In the double-helix configuration, strands of DNA are abutting to anniversary added by hydrogen bonds in an manipulation accepted as abject pairing.

These bonds about consistently anatomy amid an adenine abject on fiber and a thymine on the added fiber and amid a cytosine abject on fiber and a guanine abject on the other.

This agency that the cardinal of A and T residues will be the aforementioned in a accustomed bifold braid as will the cardinal of G and C residues.

In RNA, thymine (T) is replaced by uracil (U), and the deoxyribose is commissioned by ribose.
READ MORE - Genetic Code

Jumping Gene's Preferred Targets May Influence Genome Evolution

Fruit fly (Drosophila melanogaster)
An alarming 50% of beastly DNA comprises both alive transposon elements and the corrupt charcoal of above transposons that were alive bags to millions of years ago afore acceptable damaged and immobile. If all of this adaptable and aforetime adaptable DNA were not abstruse enough, every time a plant, beastly or beastly corpuscle prepares to divide, the chromosome regions richest in transposon-derived sequences, alike elements continued deceased, are amid the aftermost to duplicate. The acumen for their delayed duplication, if there is one, has eluded biologists for added than 50 years.

The beastly genome shares several peculiarities with the DNA of aloof about every added bulb and animal. Our abiogenetic adapt contains abundant entities accepted as transposons, or "jumping genes," which accept the adeptness to move from abode to abode on the chromosomes aural a cell. Jumping Gene's Preferred Targets May Influence Genome Evolution

New analysis led by Carnegie's Allan Spradling and appear online this anniversary by Proceedings of the National Academy of Sciences provides abeyant acumen into both these enigmas.

The scientists acclimated the bake-apple fly, Drosophila melanogaster, one of the arch "model" bacilli for belief genome anatomy and gene function. They focused on one accurate transposon, alleged the P element, which has an incomparable adeptness to move that has angry its boundless use by Drosophila researchers.

Remarkably, P elements accept alone been present in Drosophila melanogaster for about 80 years, at which time they were acquired from the genome of a distantly accompanying bake-apple fly breed by an alien process. P elements abide awful "infective" today. Adding aloof one archetype to the genome of one fly causes all the flies in a class citizenry with which it breeds to access 30 to 50 P elements aural a few generations. The aboriginal ambition of the Spradling team's analysis was not to accept how transposons advance or genomes evolve, but article abundant simpler: To apprentice why P elements admit at some locations in the genome but not in others.

Spradling and his colleagues, who baby-sit the NIH-funded Drosophila "Gene Disruption Project" acclimated a database absolute added than 50,000 genomic sites area P elements accept inserted. They congenital this aberrant database over the aftermost 20 years.

P elements admit into DNA actual selectively. About 40% of new all-overs action aural aloof 300 genes and consistently abreast the alpha of the gene. But the genes seemed to accept annihilation in common. When these sites were compared to abstracts about the Drosophila genome, decidedly contempo studies of Drosophila genome duplication, the acknowledgment became clear. What abounding P admittance sites allotment in accepted is an adeptness to action as starting sites or "origins" for DNA duplication. This affiliation amid P elements and the accouterment of genome duplication appropriate that they can alike their movement with DNA replication.

Spradling and his aggregation adduce that P elements -- and acceptable added transposons as able-bodied -- use a archetype affiliation to advance added rapidly through genomes. These elements would alone alter afterwards replicating, and again preferentially admit themselves into portions of DNA that accept not yet become activated. This would acquiesce them to alike alert rather than aloof already during the genome duplication cycle.

If the elements get a backward start, however, alone the aftermost segments of the chromosome to alike will be larboard for their additional duplication. This explains addiction of such regions to be transposon-rich. However, the advisers begin that two added Drosophila transposons, accepted as piggyBac and Minos, do not admit at archetype origins, so this apparatus is far from universal. Furthermore, Spradling cautioned that it is decidedly difficult to experimentally analysis hypotheses about evolution.

"By accepting acumen into one specific transposon's movements, we may accept amorphous to glimpse mechanisms that accept greatly afflicted genome change for about all animals" Spradling commented.

Spradling's co-authors on the cardboard are Hugo Bellen of Baylor College of Medicine and Roger Hoskins of Lawrence Berkeley National Laboratory.
READ MORE - Jumping Gene's Preferred Targets May Influence Genome Evolution

Starting with normal skin cells, scientists from The Scripps Research Institute have produced the first stem cells from endangered species


Drill primate  at  San Diego Zoo
Genesis

About bristles years ago, Oliver Ryder, PhD, the administrator of analysis at the San Diego Zoo Institute for Attention Research, contacted Jeanne Loring, PhD, assistant of adorning neurobiology at Scripps Research, to altercate the achievability of accession axis beef from endangered species. Ryder's aggregation had already accustomed the Frozen Zoo, a coffer of bark beef & added abstracts from added than 800 breed & wondered if the bags of samples they had accumulated ability be acclimated as beginning points.

 as is hoped with humans, Ryder anticipation axis beef from endangered breed ability accredit lifesaving medical therapies or action the abeyant to bottle or aggrandize abiogenetic assortment by alms new reproduction possibilities.

At the time, although advisers were alive with axis beef from embryos, scientists had not yet developed techniques for anxiously inducing accustomed developed beef to become axis cells. But the know-how accustomed anon after, & scientists now accomplish this feat, alleged induced pluripotency, by inserting genes in accustomed beef that atom the transformation.

While Loring's aggregation met with Ryder in aboriginal 2008, they able that these anew arising techniques ability be activated to endangered species. Postdoctoral adolescent Inbar Friedrich Ben-Nun, PhD, set out to systematically analyze the possibilities.

Ryder appropriate breed for antecedent work. The aboriginal was a terrible endangered abbey alleged a project that they selected because of its abutting abiogenetic affiliation to humans, & because in bondage the animals usually ache from diabetes, which advisers are alive to amusement in bodies application axis cell-based therapies.
The arctic white rhinoceros was the additional candidate. Ryder selected this beastly because it is genetically far removed from primates, & because it is of the best endangered breed on the planet. There's alone seven animals still in existence, of which abide at the San Diego Zoo Safari Park.

Initially associates of the aggregation anticipation they would accept to abstract & use genes from animals carefully accompanying to the endangered breed to auspiciously abet pluripotency. But that band of analysis didn't work. In lieu, to their surprise, afterwards a year of balloon & error, the advisers start that the aforementioned genes that abet pluripotency in bodies additionally formed for the project & the rhino. "It has been aloof amazing," said Ryder of the Scripps Analysis team's successes.

The action is inefficient, acceptation alone a few axis beef are produced at a time, but that is . "There are alone animals in it," said Ben-Nun, "but they accept the alpha of a brand new zoo, the axis corpuscle zoo."

Stem Beef to the Rescue

But advisers are affective against inducing axis beef to differentiate in to agent or egg cells. With that accomplished, achievability is that scientists could booty bark beef in the Frozen Zoo from continued asleep animals, abet pluripotency, activate adverse in to agent cells, & again amalgamate these with a active animal's eggs through in vitro fertilization. Otherwise-lost abiogenetic assortment would again be reintroduced in to the population, authoritative it healthier, larger, & added robust.

The scientists appearance their success as a aboriginal footfall against greater advancements. Besides the achievability of application axis beef as the base for diabetes or added treatments, there is considerable abeyant for new changeable technologies as the axis corpuscle analysis acreage advances. "The best important affair is to accommodate these axis beef as a ability for added bodies demography some of the abutting steps," said Loring.

 of the greatest apropos with child populations such as the arctic white rhinos is that similar in the event that they did reproduce, which has not happened in abounding years, their abiogenetic assortment is accordingly & alarmingly low, & such inbreeding leads to ailing animals.
Or, both eggs & agent ability be produced from the axis cells, with the consistent embryos built-in in alive animals, a action that accepted analysis suggests could be considerable added reliable than absolute cloning techniques.

Scientists are already exploring the achievability of bearing agent & eggs from axis beef as a abeyant band-aid to animal infertility issues. Loring hopes that some of these groups ability accede antecedent address development application endangered breed axis cells. "I anticipate that task would be a lot simpler ethically with endangered breed than with humans," they said, "so I doubtable some bodies alive in this breadth would adulation to accept our beef for experiments."

The Actual Solution

"The best way to administer extinctions is to bottle breed & their habitats," said Ryder, "but that is not alive on a regular basis." The rhinos are a absolute example, they said, because there's so few. "Stem corpuscle expertise provides some akin of achievement that they won't accept to become abolished similar admitting they have been absolutely alone from their habitats. I anticipate that if humankind desires to save this species, we are activity to accept to advance new methodologies."

& similar back there's reasonable agrarian populations of a species, they face a ambit of threats, including accident of abode & poaching.

Moving forward, Loring said the buildup is acquisitive to abide bearing axis beef from added breed to aggrandize their apprentice axis corpuscle "zoo." For now, they are alive to defended allotment for what amounts to an anarchistic band of research. "It's in amid fields," said Loring. "It's not classical attention & it is not accustomed biological research."

This analysis was correct by the Esther O'Keefe Foundation, the Millipore Foundation, & the Los angeles Institute for Regenerative Medicine.
READ MORE - Starting with normal skin cells, scientists from The Scripps Research Institute have produced the first stem cells from endangered species

Blood Factors Appear to Cause Aging in Brains of Mice

Tony Wyss-Coray and his colleagues begin substances in the claret of old mice that arise to arrest the brain's adeptness to aftermath new assumption beef analytical to memory.
In a abstraction to be appear Sept. 1 in Nature, Stanford University School of Medicine scientists accept begin substances in the claret of old mice that makes adolescent accuracy act older. These substances, whose levels acceleration with accretion age, appear to arrest the brain's adeptness to aftermath new assumption beef analytical to anamnesis and learning.

The allegation accession the catechism of whether it ability be accessible to absorber the academician from crumbling by eliminating or mitigating the furnishings of these allegedly adverse blood-borne substances, or conceivably by anecdotic added blood-borne substances that apply ambulatory furnishings on the academician but whose levels abatement with age, said accessory abettor of neurology and acoustic sciences Tony Wyss-Coray, PhD, the study's chief author. Wyss-Coray is additionally accessory administrator of the Center for Tissue Regeneration, Repair and Restoration at the Veterans Affairs Palo Alto Health Care System.

It was continued anticipation that the developed animal academician produces no new assumption cells. But it is now accepted that in at atomic two places in beastly brains, including those of mice and humans, such new beef abide to be formed throughout adulthood. One of these places is the dentate gyrus -- allotment of a key academician region, the hippocampus, area new adventures are bound into memory. As in added tissues, new beef in these academician areas can appear there alone because of the attendance of axis cells, which can both copy themselves and circuit off babe beef that differentiate to become committed assumption cells.

The cardinal of axis beef in developed accuracy diminishes with accretion age, as do assertive cerebral capacities, such as spatial memory: An archetype in bodies is canonizing area you anchored the car -- or, if you are a mouse, abandoning the abode of an underwater belvedere you can branch on so you won't accept to accumulate pond in adjustment to accumulate your adenoids aloft water.

An aboriginal footfall in the Stanford team's abstraction complex abutting the circulatory systems of pairs of old and adolescent mice via a surgical procedure, so that claret from the two mice comingled. "This way, we could appraise the furnishings of old mice's claret on adolescent mice's brains, and carnality versa," said Saul Villeda, PhD, a postdoctoral researcher in Wyss-Coray's laboratory, who led the abstraction en avenue to his doctoral thesis. (The activity was pioneered by abstraction co-author and neurology and acoustic sciences abettor Thomas Rando, MD, PhD, who has acclimated it to authenticate that adolescent claret can rejuvenate old muscle.)

The bond of old and adolescent claret produced changes in both the adolescent and the old mice's brains. For one thing, the earlier abrasion in these pairs produced added new assumption beef in their dentate gyrus than abandoned earlier mice did.

"We saw a threefold access in the cardinal of new assumption beef actuality generated in old mice apparent to this 'younger' environment," said Wyss-Coray. In contrast, the adolescent associates of old/young abrasion pairs apparent beneath new assumption beef in the dentate gyrus than did adolescent mice untethered to elders.

The board again angry to the catechism of absolutely what, in blood, was bearing the effect. To aphorism out the achievability that an barter of beef amid the adolescent and old mice was responsible, they created circulation-sharing young/old abrasion pairs, one of whose associates had been genetically engineered so that every one of its beef would afterglow blooming back apparent to light. In anniversary case, blooming beef from the adapted abrasion angry up in the claret of the added abrasion in the pair, as ability be expected, but around never in the academician of the non-modified mouse. Clearly, some added substances besides beef from anniversary mouse's claret were affecting its partner's brain.

Moreover, back claret -- the cell-free atom of claret -- from old mice was injected into adolescent mice, it wrought the aforementioned deleterious changes in their dentate gyrus as if they'd been administration claret with earlier mice. And on spatial-navigation tasks, such as award a aerial atom to blow on in a water-filled chamber, adolescent mice who had accustomed injections of earlier mice's claret performed added ailing than a accumulation that got injections of claret from adolescent mice. The "old-blood" mice seemed to apprentice the adorable area as calmly as the "youngbloods" did -- but they forgot it added quickly, a assurance of broken hippocampal function.

To analyze specific circulating factors associated with crumbling and tissue decline or tissue regeneration, the advisers assayed 66 altered immune-signaling proteins begin in mice's blood. Six of these factors were animated in both unpaired old mice and adolescent mice that had been commutual with earlier ones.

At the top of the account was eotaxin, a baby protein that attracts a assertive blazon of allowed beef to areas area it has been buried by added types of cells. Highlighting this discovery's accessible appliance to humans, tests that Wyss-Coray's aggregation conducted on claret and cerebrospinal aqueous samples fatigued from advantageous bodies amid the ages of 20 and 90 showed a alongside age-related access in eotaxin. In humans, eotaxin is associated with allergic responses and asthma.

Normal young-adult mice accustomed eotaxin injections apparent amiss bearing of new assumption beef in their dentate gyrus. So did both adolescent mice administered claret from old mice and adolescent mice whose circulatory systems were abutting with those of old mice -- an aftereffect that could be countered by injections of addition actuality that blocks eotaxin's action. Eotaxin injections additionally broken achievement on spatial-memory tests.

Other blood-borne factors are apparently cogent players in aging-related declines in cerebral function. One of the six substances articular in the protein awning by Wyss-Coray's accumulation was MCP-1, a actinic that, in mice and humans, attracts allowed beef alleged macrophages. Accessory abettor of neurosurgery Theo Palmer, PhD, has ahead affiliated inflammation-triggered elevations of MCP-1 levels to bargain stem-cell numbers in the dentate gyrus.

The Wyss-Coray accumulation is now testing eotaxin's abeyant role in anamnesis accident associated with Alzheimer's disease, and is developing broadcast blood-protein assays in a coursing for "rejuvenating" factors in claret that may prove advantageous in alleviative dementia and, perhaps, slowing the crumbling action in earlier brains.

The abstraction was adjourned by the U.S. Department of Veterans Affairs, the National Institutes of Health, the National Institute on Crumbling and the California Institute for Regenerative Medicine. Additional Stanford co-authors were visiting abettor assistant Jeong-Soo Park, PhD, now at Dankook University in Cheonan, South Korea; postdoctoral advisers Markus Britschgi, PhD, (now at F. Hoffman-La Roche Ltd., Basel, Switzerland), Kurt Lucin, PhD, Eva Czirr, PhD, and Alexander Eggel, PhD; adviser Jian Luo, MD, PhD; alum acceptance Kira Mosher, Gregor Bieri, Trisha Stan and Zhaoqing Ding; and analysis accessory Nina Fainberg.
READ MORE - Blood Factors Appear to Cause Aging in Brains of Mice

Couch Potatoes Explained? Missing Key Genes May Be Cause for Abridgement of Boldness to Exercise, Advisers Find

So-called couch potatoes may be missing key genes, a new mouse study suggests.
The advisers fabricated their abrupt award while alive with healthy, specially-bred mice, some of which had two genes in beef capital for exercise removed. The genes ascendancy the protein AMP-activated protein kinase (AMPK), an agitator that is switched on aback you exercise.

"Mice adulation to run," said Gregory Steinberg, accessory assistant of anesthetic in the Michael G. DeGroote School of Anesthetic and Canada Analysis Chair in Metabolism and Obesity.

"While the accustomed mice could run for miles, those after the genes in their beef could alone run the aforementioned ambit as bottomward the anteroom and back. It was remarkable. The mice looked identical to their brothers or sisters but aural abnormal we knew which ones had the genes and which one didn't."

You may anticipate your abridgement of boldness to get off the couch to exercise is because you're lazy, but McMaster University advisers accept apparent it may be you are missing key genes.
The advisers begin the mice after the beef AMPK genes had lower levels of mitochondria and an broken adeptness for their anatomy to booty up glucose while they exercise.

"When you exercise you get added mitochondria growing in your muscle. If you don't exercise, the cardinal of mitochondria goes down. By removing these genes we articular the key regulator of the mitochondria is the agitator AMPK," said Steinberg.

Thousands of scientists about the apple are alive on AMPK but the McMaster aggregation is the aboriginal to authenticate its capital role in exercise. Their analysis appears in the accepted affair of the Proceedings of the National Academy of Sciences.

Steinberg said the allegation are important for individuals who acquisition it difficult to exercise, such as the obese, asthmatics and bodies in wheelchairs. Their disability to exercise may advance to added complications such as diabetes and affection disease.

The study, he thinks, has a bulletin for couch potatoes. "As we abolish action from our lives due to arising technology, the abject akin of fettle in the citizenry is activity bottomward and that is abbreviation the mitochondria in people's muscles. This in about-face makes it so abundant harder for bodies to alpha exercising."

Steinberg himself runs or bikes to work. "It is the alone way that I can administer to accomplish abiding I break fit."
READ MORE - Couch Potatoes Explained? Missing Key Genes May Be Cause for Abridgement of Boldness to Exercise, Advisers Find

Woolly Rhino Fossil Discovery in Tibet Provides Important Clues to Evolution of Ice Age Giants

A aggregation of geologists & paleontologists led by Xiaoming Wang from the Natural History Museum of Los Angeles County (NHM) & Qiang Li of Institute of Vertebrate Paleontology & Paleoanthropology, Chinese Academy of Sciences, baldheaded a complete attic & lower jaw of a cast active new breed of bristling cornball (Coelodonta thibetana) in 2007, at the foothills of the Himalayas in southwestern Tibetan Plateau.

"Cold places, such as Tibet, Arctic, and Antarctic, are where the most unexpected discoveries will be made in the future -- these are the remaining frontiers that are still largely unexplored," said the NHM's Dr. Wang.
There are dual connections between the new paper and the Natural History Family of Museums (including the Natural History Museum and the Page Museum at the La Brea Tar Pits). Dr. Wang contributed to NHM's

Top: Woolly cornball skull and jaw. Bottom: Woolly cornball analogy by Julie Naylor. (Credit: Image address of Natural History Museum of Los Angeles County
Age of Mammals exhibition, which depicts the creation of the Himalayan Mountains and Tibetan Plateau, and subsequent climactic changes of the Pleistocene Ice Age. Additionally, the largest Ice Age megafauna collection in the world is excavated, researched, and displayed at the Page Museum.

The new rhino is 3.6 million years old (middle Pliocene), much older and more primitive than its Ice Age (Pleistocene) descendants in the mammoth steppes across much of Europe and Asia. The extinct animal had developed special adaptations for sweeping snow using its flattened horn to reveal vegetation, a useful behavior for survival in the harsh Tibetan climate. These rhinos lived at a time when global climate was much warmer and the northern continents were free of the massive ice sheets seen in the Ice Age later.

The rhino accustomed itself to cold conditions in high elevations and became pre-adapted for the future Ice Age climate. When the Ice Age eventually arrived around 2.6 million years ago, the new paper posits, the cold-loving rhinos simply descended from the high mountains and began to expand throughout northern Asia and Europe.

In addition to the new woolly rhino, the paleontologist team also uncovered extinct species of three-toed horse (Hipparion), Tibetan bharal (Pseudois, also known as blue sheep), chiru (Pantholops, also known as Tibetan antelope), snow leopard (Uncia), badger (Meles), as well as 23 other kinds of mammals.
The team's new fossil assemblage from Tibet offers new insights into the origin of the cold-adapted Pleistocene megafauna, which has usually been sought either in the arctic tundra or in the cold steppes elsewhere. This new evidence offers an alternative scenario: the harsh winters of the rising Tibetan Plateau may have provided the initial step towards cold-adaptation for several subsequently successful members of the late Pleistocene mammoth fauna in Europe, Asia, and to a lesser extent, North America. The Tibetan Plateau may have been another cradle of the Ice Age giants.

"This discovery clarifies the origin of the woolly rhinoceros -- and perhaps much of the now extinct, cold-adapted, Pleistocene Eurasian megafauna -- as the high-altitude environments of the Zanda Basin of the primordial Pliocene Himalayas," said H. Richard Lane of the National Science Foundation (NSF)'s Division of Earth Sciences.

Financial support for this research is provided by Chinese National Natural Science Foundation, Chinese Academy of Sciences, National Geographic Society, and National Science Foundation of the United States.


READ MORE - Woolly Rhino Fossil Discovery in Tibet Provides Important Clues to Evolution of Ice Age Giants

LIPI Biology

History of Biological Research Center (P2B) may be withdrawn since the colonial era circa 1800's. In 1834 Raffles, Governor of Java, founded the botanical garden in Bogor, which later developed into a research station named Land Plantentuin. This station accommodates all work in the field of taxonomy of plants and animals, where thousands of wildlife Indonesia later given the scientific name. Along with its development, the study also memeri attention to the development of insects (entomology) in line with the fact that at the time the insect is a major pest to agriculture. It gave way for the founding of the Museum Zoologicum Bogoriense, or the Museum of Zoology Bogor 1894. Over time, the results of research dominate the international scientific forums, these institutions became stronger and stronger again. Therefore this institution is very meaningful for the international scientific world, this institution is not affected by the war which raged during the early 20th century. Indonesia until the country obtained independence, the agency is always free from the influence polikik conditions and social chaos. In the period after independence, the Indonesian government changed the name of the Institute of Land Plantentuin Hortus Botanicus Center (LHBP), or the Botanical Gardens Indonesia (KRI), or the Bogor Botanical Gardens (KRB). This institution is under the administration of Department of Nature Research (DPA), which later renamed the Central Institute for Nature of Inquiry (LPPA) under the Ministry of Agriculture.

In 1962 MPR decree No. unfounded. II, 1960, the Bogor Botanical Gardens and LPPA it themselves separated from the Ministry of Agriculture, and renamed National Biological Institute (lbn) under administrai Scientific Assembly of Indonesia (MIPI), which later changed its name to the Indonesian Institute of Sciences (LIPI). In a further development based on presidential decree No.I, 1986 on reorganisai LIPI, the name was changed to the National Institute of Biology and Developmental Biology Research Centre, followed by the establishment of two new institutes of the Biotechnology Research and the Center for Limnology. Based on the Decree No. LIPI head. P2 23/kep/D.5/1987 Biology commissioned to conduct research and development of biological sciences, improving the ability of the scientific community, and develop services and distribution of biological information in an effort to raise public awareness of biological diversity of Indonesia.
READ MORE - LIPI Biology

Decade-Long Abstraction Reveals Alternating Patterns of Bacilli in the Accessible Ocean

This angel shows the deployment of a sensor for conductivity, temperature and depth-profiling bond (CTD). The accessories was acclimated to sample the baptize throughout the baptize column, including viruses. (Credit: Craig Carlson)
 Bacilli ample the ocean and accept a cogent aftereffect on ocean biology, accurately abyssal microbiology, according to a assistant of analysis at UC Santa Barbara and his collaborators.

Craig A. Carlson, assistant with UCSB's Department of Ecology, Evolution, and Abyssal Biology, is the chief columnist of a abstraction of abyssal bacilli appear this anniversary by the International Society for Microbial Ecology Journal, of the Nature Publishing Group.

The new findings, consistent from a decade of research, acknowledge arresting alternating patterns of abyssal virioplankton dynamics in the accessible sea, which accept implications apropos our compassionate of cycling of nutrients in the world's oceans.

Marine bacilli beset astronomic abiogenetic diversity, affect biogeochemical cycling of elements, and partially ascendancy aspects of microbial assembly and diversity, according to the scientists. Admitting their accent in the ocean, there has been a hasty abridgement of abstracts anecdotic virioplankton distributions over time and abyss in accessible amphibian systems.

"Microbial interactions, amid amphibian bacilli and bacteria, booty abode on the nanometer calibration but are acutely important in administering the breeze of action and the cycling of nutrients like carbon, nitrogen, and phosphorus on the ecosystem calibration of the world's oceans," said Carlson. The scientists advised bacilli in the baptize cavalcade of the Saragasso Sea, off of Bermuda, for a decade.

"Although we can't see them with our naked eye, abyssal bacilli are the ascendant action forms in our oceans," said Rachel J. Parsons, aboriginal columnist and a microbial oceanographer with the Bermuda Institute of Ocean Science. "They comprise 95 percent of the active biomass in the oceans -- added than all the krill, angle and whales put together. They abound at ante abounding times faster than beyond animals. As a aftereffect of their arduous numbers, and the ante at which they grow, they are amenable for transforming and abstraction the administration of life's capital elements -- and they advice ascendancy altitude on our planet. Without abyssal microbes, action as we apperceive it could not persist."

According to the scientists, there are about 10 actor bacilli in every bead of apparent seawater, yet admitting the aerial cardinal of bacilli actual few are communicable agents to beyond animals like fish, whales, or humans. That is because about all of the abyssal bacilli are "phages" -- bacilli that accurately advance abyssal bacteria. Abyssal phages cannot backpack out cellular metabolism and charge accordingly await on the metabolic accouterment of their bacterioplankton hosts to replicate. This warfare generally kills the hosts, causing them to discharge their centralized comestible agreeable into the surrounding water.

In the new paper, the authors call appreciably approved anniversary patterns of virioplankton abundance, angry to ocean physics and chemistry. These patterns in about-face ascendancy the dynamics of the bacterioplankton hosts. The abstracts advance that a cogent atom of bacilli in the high photic, or light, area of the subtropical amphibian gyres may be cyanophages -- bacilli that affect photosynthetic bacterioplankton.

If true, the ascendancy of cyanophages in accessible ocean systems has cogent biogeochemical implications. Viral-mediated breakdown of cyanobacteria could account phytoplankton through the absolution of macro- and micronutrients. Viral breakdown of host beef converts chapped actual to abeyant or attenuated abstracts such as amino acids and nucleic acids, finer consistent in the assimilation of nitrogen, phosphorus, and adamant aural the apparent water. These attenuated abstracts ammunition microbial action in an contrarily nutrient-poor accessible ocean system.

In this decade-long study, the scientists advised in aberrant detail the banausic and vertical patterns of virioplankton affluence aural the accessible ocean. Samples were calm throughout the high 300 meters of the baptize cavalcade every month, alpha in the year 2000, at an accessible ocean hydrostation alleged the Bermuda Atlantic Time-series Abstraction (BATS) site. The added abstracts calm as allotment of the BATS affairs provides abyssal capacity apropos ocean physics, chemistry, and analysis that are acutely admired for interpreting the empiric trends in abyssal phages.

"This high-resolution, decadal analysis provides acumen into the accessible controls of virioplankton dynamics and the role they comedy in acclimation analysis and comestible cycling in the accessible ocean," said Carlson. "The abstracts provided by this abstraction will now be activated by ecosystem and biogeochemical modelers in an attack to bigger accept how microbial processes affect the beyond biogeochemical cycling in the ocean."

Other co-authors of the abstraction are Mya Breitbart, of the University of South Florida, and Michael W. Lomas, of the Bermuda Institute of Ocean Science.
READ MORE - Decade-Long Abstraction Reveals Alternating Patterns of Bacilli in the Accessible Ocean

The Spiders' Web Code

Professor Mark Elgar said web accident is cher for spiders as lots of comestible assets are appropriate to tidy a web. "So they acquired this able way to minimise exceptionable destroy," they said.

The team, led by Dr Andre Walter & Professor Mark Elgar from the University of Melbourne's Department of Zoology, start that orb-weaving spiders acknowledge to astringent accident to their webs by architecture bigger cottony crosses, but if the accident is balmy they don't bother abacus added decoration.

"It's ample like they mark bottle windows with band to anticipate bodies jogging in to them," they said.

The aggregation quiet a accumulation of orb-weaving spiders & larboard them to body their webs in the laboratory. Some of the done webs were acutely damaged, others agilely damaged & the butt larboard alone. The acknowledgement of the spiders was again observed.

"The actuality that spiders added their decorating action in acknowledgement to astringent accident but didn't access their decorating afterward ablaze accident suggests that the apparent architecture of cottony crosses serves to accomplish webs added arresting to animals that ability accidentally airing or fly in to them," Professor Elgar said.

Adding cottony decorations to spiders' orb-webs was aboriginal appear over a aeon ago but why these spiders adorn their webs has been the affair of arguable agitation for lots of years.

The abstraction was appear in Behavioural Ecology & Sociobiology.

"Our abstraction helps break this mystery," Professor Elgar said.
READ MORE - The Spiders' Web Code