The Human As a Habitat

The human body serves as a suitable home for a number of microorganisms, and those microbes that become adapted to the body are called resident flora. The first exposure of every individual to microbes occurs during the birth of the individual , at which time microbes from the mother’s vagina can enter the womb. During the birth process, the baby unavoidably comes into intimate contact with the birth canal and within 8 to 12 hours after delivery, the newborn typically has been colonized by bacteria such as streptococci, staphylococci and lactobacilli, acquired primarily from its mother.
The nature of the flora that initially colonize the large intestine depends upon whether the baby is bottle- or breast-fed but bottle-fed infants tend to acquire a mixed population of lactobacilli, enteric streptococci, and staphylococci. In contrast, the intestinal flora of breast-fed infants consists primarily of Bifidobacterium species whose growth is favoured by a growth factor from the milk which enable this bacterium to converts sugars into acids that protect the infant from infection by certain intestinal pathogens.
The skin, the mouth and portions of the respiratory and genitourinary tract all continue to be colonized as contact continues with family members, hospital personnel, the environment and food.
Anthony Kwame Arhin.

How can a weed become a witch?

In worldwide cultures, religious and mythologies, a witch denotes someone who possesses certain kinds of supernatural or magical powers in order to inflict harm or damage upon people. This qualification was applied to a wide spread parasitic weed: Striga hermonthica and the question remains “how a weed can become a witch”? In general a weed is any plant that is considered by the user of the term to be harmful, a nuisance (to crop) and unwanted where it occurs; and a parasitic weed is a weed that requires the presence of the host: (crop) for its development. S. hermonthica germinates only in the presence of the host and establishes as soon as it germinates a connection between the host’s roots and take water and nutrients from the host plant. The fact that S. hermonthica possesses a high proliferation, causes most of its damages in the soil (40-100% of yield losses) before appearing above the soil and, till now no control method has been discovered; thus this makes the weed to be considered as possessing a supernatural or magical power, so called witchweed. For any scientist going to deal with S. hermonthica, the main question he needs to answer is “Can you kill a witch”?

KOLOMBIA Adjiguita Yao

Do you know what are water wheels?

Water wheels are a special kind of wheels which were made from wood as nuts, poplar, berries, and apricot, they were designed by Aramaic engineers in the fifth century to raise the level of water of the Aasei river, for drinking and irrigation. Each wheel has wooden boxes or pockets around the circumference which are filled up with water when the wheel is rotated and pushed by river water power, which was intend used for wheat milling and olive squeezing to extract oil. The water wheels are found only in Hama city because the valley river is lower than the ground city level by more than ten metres. In the past, there were 106 wheels in total, 25 inside the city while the rest were outside, but today, only 40 of them are left, and just 19 present within the city are still working. The people of Hama city named these wheels after family names as Kielania, Tawafra and Moaeadia, and they used them as landmarks and logo. Hama history is linked with the water wheels, and they even made a mosaic portrait of the water wheel, which is found in the Hama museum, as a unique portrait in the world.


Fateh Toumi

Do you know Lucy?

Lucy was a female hominoid that lived in what is now called the Awash Valley in Hadar some 3.2 million years ago, and when her skeletons were discovered in 1974, Ethiopia then claimed that it was the first dwelling of mankind, however, recent findings in Kenya, such as the discovery of Kenyanthropus platyops in 1998, have come to challenge Lucy as to who really is the direct ancestor of humankind. The discovery would change the prevailing theories of how, when and where human ancestors climbed out of trees and began walking up right and using tools. Lucy’s scientific name is Australopithecus afarensis, the first word means “Southern Ape” and the second word signifies she was discovered in the Afar region. When she was discovered, only a little over half of her skeletons were found, and she probably did not live more than 20 years and weighed around 60 pounds and stood three and a half feet.

But how do you know that Lucy is female, when she died, how she was walking, and why she called? Donald Johanson, the anthropologist from Chicago University who discovered her, tells us all and you can get it the following link, http://www.asu.edu/clas/iho/lucy.html.

Entomopathogenic Nematodes as Biological Control of Insects

Of all nematodes studied for biological control of insects, those in the families Steinematidae and Heterorhabditidae have aroused the most interest, and information about them is growing exponentially. These two families mutually associated with gram negative facultative anaerobic bacteria, and the bacterium carried by Steinematidae is usually a species of the genus Xenorhabdus, and that carried by Heterorhabditidae is a species of Photorhabdus. The free living, non-feeding infective juveniles of these nematodes possess attributes of both insect parasitoids or predators and microbial pathogens, like parasitoids/predators, they have chemoreceptor and are motile; like pathogens, they are highly virulent, killing their hosts quickly, and can be cultured easily in vitro, have a high reproductive potential, and have a numerical but no functional response. They have a broad host range, are safe to vertebrates, plants, and other non target organisms, have been exempt from registration in the United States, are easily applied using standard spray equipment, and are compatible with many chemical pesticides. These nematodes, because serve as vectors of Xenorhabdus and Photorhabdus bacteria, termed Entomopathogenic, reinforcing the link between insect nematology and insect pathology. Therefore, these fascinating animals may contribute more to science than their use solely as biological control agents, as they may be useful tools in understanding the evolution of parasitism and symbiosis and the mechanism of insect resistance to infection.

Tewodros Tamiru

The most horrific and dangerous creatures

Parasitic worms are the most horrific and dangerous creatures in the animal kingdom because they can literally eat our body from the inside!
The blood fluke (Trematode) for instance, can be found in tropical forests, this fluke can burrow through the skin of a mammal, enter the bloodstream and after some time it will migrate to the bladder where it can live for up to 30 years!
Other types of widespread parasitic worms are roundworms, which may be present in one out of every four people.
These worms are found attached to the stomach wall and feast on the same food as their host.
Humans may also be infected by a filarial worm, which is as thin as a hair, as long as a forefinger, and found convoluted in the lymph glands feeding on body fluids.
To define the symptoms of a parasitic infection is an extremely difficult task, so this may therefore be a reason why most of the time we might never even know if we are infected with these parasitic worms, which use our bodies as their home.


Natalia Grushko

Amazing nematodes

Did you know that nematodes (phylum Nematoda), also called roundworms, are one of the most diverse animals, both in number of species, estimated for over 500 000, and number of individuals as well?
Did you know that nematodes can live almost everywhere, in oceans, seas, rivers, lakes, plants, animals and humans, from poles to the equator, from the deepest ocean sites to the highest mountains?
Did you know that the smallest nematode, Hapalomus minutus, is just 82 µm long, and the largest one, Placentonema gigantisima, has a body length of 8.4 m? 
Did you know that the only survivor on the Space Shuttle Columbia Disaster was a nematode?
Did you know that 7 Nobel prizes were obtained for researches on just one nematode species, Caenorhabdithis elegans, in less than 10 years?
Did you know that some nematodes can undergo cryptobiosis, and stay in that "sleeping-almost-dead condition" for more than 40 years, and, did you know the fact that, they are truly amazing?

Nikola Grujic

Technology, our best friend

What would you do when technology lets you down? I recently had a chance to find out first hand when the machine I used for contact angle measurements went out of order.

Fortunately there was a plan B, which meant I had to conduct those experiments the old-school way using a device that consisted of a fluorescent screen to enlarge the image of a manually created droplet. The droplet was made using a syringe and had to be as perfectly round as possible to minimize errors (try it yourself, it isn’t as easy as it sounds), afterwards its height and length were measured on the screen using a caliper. Getting the needed results from the measured data wasn’t a walk in the park either, as this was done using a rather archaic program which was not able to make the necessary calculations for multiple experiments in a row, nor was it able to save this data in a digital output file.

I guess this story shows how big of a help technology is to scientists these days; not only does it allow us to measure and see things that weren’t detectable before, it also saves us precious time…

David Weinberger

STONY VINEYARDS

Stony vineyards are unique for the fact that a stone desert was turned in to the field with the most quality agricultural products. These vineyards were founded in the early 1980’s in southern part of Bosnia and Herzegovina, area where the sun ruthlessly heats six months a year, and where common landscape is karst. Instead of tractors, powerful machines, rippers and bulldozers were used to prepare substrate with negligible amount of soil for planting grapes. The complete area of 100 ha was planted with the most famous autochthon variety of white wine, Zilavka. Only variety that was born in such hot climate and soil of so specific characteristics could get such a good result in those hard conditions. The grapes from this location, characterized by high degree of sugar, are elaborated with controlled fermentation and as a result it gives us unique high quality dry wine, named Stone wine.

Branimir Njezic

An ill wind

On December the 3rd 1943, the German army bombarded the harbour of Bari in Italy, which was full of boats containing supplies for the Allied armies, who were fighting against the Italians. One of the bombs struck the USS Liberty ship, which carried an extremely high amount of explosives and 100 tons of mustard gas. Many civilians and soldiers were caught by the gas, which affected and killed the white blood cells. Rhoads, a doctor who worked for the US army and lived in Bari at that time, was so curious about the effect of mustard gas on the human body that he began to examine patients. He discovered that infections were extraordinarily, even in patients who were seriously affected by the mustard gas. Rhoads found out that the gas only damages the white blood cells, so it could be used in curing leukemia (a disease which causes an excess of white blood cells in the human body) and it was the beginning of the development of chemotherapy.

stijn steuperaert

Beta Decay

When a nuclide is unstable, because it has too many neutrons or protons, it will always try to regain its stability through radioactive decay or in other words loss of the excess nucleons. Beta decay is one form of radioactive decay which can be divided into two types, what type a nuclide undergoes depends on what nucleon is in excess.

The first type is β- or β-particle production, this means that the nuclide produces a β-particle, which is an electron, by transforming a neutron into an electron and a proton.
The second type is β+ or positron production and is very similar to the first type, differing only in the fact that the nuclide produces a positron instead of an electron and transforms a proton instead of a neutron. The positron is considerd to be the antiparticle of an electron since it has the same mass but an opposite charge.

This is just one of the possible transformations unstable nuclides can undergo and many nuclides need more than one transformations to reach a stable form.

Gertjan Vancoillie

Our world once a slime world?

You might consider yourself lucky, not having been born from around 3.5 billion to roughly 2.2 billion years ago....



And if that is not the case then maybe you should, because in that particular time-span -which actually envelops three-quarters of the history of our planet- the earth was ruled by nothing but microbial life. Which is a fancy way of saying that our world then, with its unfavourable environmental conditions (very acid or basic environments, not a lot of oxygen, ...) and its vast amount of tiny organisms, was once a slime-world.
We know this because geologists -witty people who often study rocks- found evidence of this early and simple life in several rock formations located at outcrops of ancient rock material and because they studied the genesis of these rocks that hold a link to the distant history of this earth.
An indicator of this early life that is well-known to these scientists lies in certain laminated rocks called 'stromatolites' that are formed due to the trapping and cementing of sediment by bacterial mats and of which the eldest date from 3.5 billion years BP (before present). Therefore stromatolites are the only fossils recording such an early (and also vast) part of the history of life on an earth covered by microbial mats because, well, the conditions were right and also because there weren't any multicellular organisms to graze them yet.

(Samuël Delefortrie)

From Claviceps purpurea to LSD

Claviceps purpurea is the prominent member of the Ergot-group that grows on rye, wheat and other related grains. It produces toxic alkaloids, like ergotamine, which have many effects on the blood circulation system and can create hallucinations.

In the Middle Ages, human poisoning in Europe was common due to the consumption of bread made from these infected grains. Back then, man also believed that the hallucinations were created by witches which has lead to the many witch-hunts.

Nowadays it is known that is was actually the ergot alkaloids that created these hallucinations and this inspired the Swiss chemist Albert Hofmann to synthesize LSD or lysergic acid diethylamide: a derivative of lysergic acid, which is a chemical subpart of the ergotamine.

LSD is known as a psychedelic drug: the experience after intake is characterized by an increase of imaginary power and a change in perception of the world.

Bo Van de Moortel

Central Dogma of Molecular Biology

The ‘Central Dogma of Molecular Biology’ enunciated by Francis Crick in 1958 answeres the question about the complex structure and the mode of function of the body of animals. A cell, the smallest unit of the body, is composed of ‘proteins’ like a precise machine to form the functional basis of life. The ‘Central Dogma’ describes the series of steps involved in producing ‘function specific’ protein from DNA (a nucleic acid occurs in the cell chromosome) where all the informations about life remain coded. In the first step, the replicating DNA is copied or transcribed as mRNA (messenger RNA) in the cell nucleus with the help of an enzyme called RNA polymerase.The transcribed and processed mRNA then moves from nucleus to the ribosome of cytoplasm where it is decoded or translated into amino acids with the help of tRNA (transfer RNA).The newly formed amino acids are linked together by the aid of various enzymes to form protein for performing specific function exactly in a way it was blueprinted in the source DNA.

Sukalpa Das, Masters of Nematology

Do You Know Pitcher Plants?

Imagine a beautiful plant that attracts insects to their death by a charming scent and inviting pigmentation. Pitcher Plants have a “pitcher-like” shape that features a deep cavity filled with liquid. Insects are attracted visually and or by smell to it. Once there, the insect such as a fly falls into the pitcher like body and cannot escape because the sides are slippery and ridged.
The liquid does three things to the insect: trap, cover and dissolves it. As the insect is dissolved it becomes a soup of amino acids, nitrogen, phosphorus, peptides, and other minerals from which the pitcher plant absorbs for its food and nutrition. Therefore, Insects be cautious… everything that smells great and is beautiful is not always good for you; however, it is good for the wellbeing and nourishment of the Pitcher Plants.

Awol Seid Ebrahim

Gelada - "Bleeding heart baboon"

Gelada (Theropithecus gelada) sometimes called Gelada baboon, is a species of old world monkey is found only in Ethiopian high lands, Semien Mountains, with large populations. The males being about 30inches tall without tail and twice the size of the females. They do have bare red skin areas on the chest, which are actually two triangles, and another crescent-shaped on the throat, unlike the females the patches in males are always red and do not change color. Their handsome appearance and the beauty of their habitat is one thing, but perhaps the most fascinating aspect of these creatures is their social structure which is the most complex in the animal kingdom after that of man. You can see them grouped into herds of up to 400 or so individuals, each of which is made up in turn of “harems”, which are groups of from two to eight females and young ones with one dominant male and often one hanger-on called a “follower”, who ingratiates himself with the juvenile females with a view to enticing them away in due course and forming his own harem. Harem owning males do not attempt to steal each others’ wives.

Eba Alemayehu Simma

Gene Silencing

Gene Silencing

Gene silencing or RNA interference (RNAi) is a biological occurring mechanism in higher eukaryotes by which gene expression is regulated by short double-stranded RNA sequences. The mechanism occurs after the gene has been transcribed , and it was initially considered a phenomenon limited to petunias and a few other plant species, recently it has become clear that post transcription gene silencing occurs in both plants and animals and has roles in viral defence and transposon silencing mechanisms. Perhaps most exciting phenomenon and one of the hottest topics in molecular biology today is the use of RNA interference (RNAi) by introducing double-stranded RNA (dsRNA) as a tool to knock down expression of specific genes in a variety of organisms. In 1998, Andrew Fire and Craig Mello published a break-through study in the mechanism of RNA interference and they established that, only injection of double-stranded RNA (dsRNA) into C.elegan led to an efficient loss of the target mRNA. Following this break-through, researchers are no longer restricted to classical forward genetic screening where the gene can only be studied by inducing mutation then sorting of the phenotype of interest instead, gene silencing provide an alternative approach known as “Reverse genetics” where the functional study of a gene starts with the gene sequencing rather than mutant phenotype. Using reverse genetics one can investigate the function of all genes in a gene family, one can study the function of a gene found to be involved in a process of interest in another organism, something not easily done with forward genetics.

Katemani Mdili

PINC 2008/09

A strange animal

Do you know the Mount ''Nimba''? , the highest mountain chain located at the intersection of the borders of Ivory Coast, Guinea and Liberia. On this mountain chain, specifically in the Guinean part is a strange amphibian, Nectphrinoides occidentalis, which has disturbed the rules of the taxonomy. Unlike all other known amphibians which have an oviparous reproduction, this little frog has a viviparous reproduction, it reproduces as a mammal. What makes this animal very strange is its adaption to its living environment, outside of which it can not survive and all the attempts to adapt it to an environment other than the Guinean part of Mount ''Nimba'' have failed until now. According to the inhabitants of this region, the animal would be the protector of the enormous natural wealth hidden under the mountain. The place attracts each year thousands of people desirous to see this curious animal.

DIAKITE Mohamed.
Master Nematology

Plant-parasitic Root Knot Nematode, Meloidogyne

The root knot nematode Meloidogyne incognita is a plant parasitic nematode that lives in roots of tomato plant (and other plants). It sucks water and nutrients out of the roots before the tomatoes can use them. They live in the soil, enter the root tip and set up camp. The females become very small round balls with a tiny head. They cannot escape once they are in this form in the root. They lay eggs in the soil, which hatch into juveniles that find roots to make their home.

Ngala Bruno M.

God in bread?

During the Middle-Ages, poor people got ill by eating brown bread. Most of them suffered from hallucinations, gangrene or even died. The reason for this disease was the mould Ergot (Claviceps purpurea) that infected cereals which where used in brown bread. In those times, ill people went to a monastery where they hoped to find God’s mercy. In the monastery the priests only ate white bread and due to the absence of the mould people got better which strengthened their believe in God.
Through history, eating brown bread wasn’t always healthier than eating white bread.

Matthias Moens

Quantum Comb

Quantum physics is probably one of the most notorious subjects in science due to its hard mathematical nature and the absence of practical examples clearly governed by its laws.
One of the main ideas in quantum physics is the concept of quanta, these are small packages of energy which cannot be further divided and can therefore be seen as building blocks by which matter can be described.
At the university of Boston, a “multi molecular-comb” (see figure) has been developed which starts to rollover, back and forth, from its left side to its right when exposed to extreme temperature (-110°C) and a high energy electrical field (1,5 GHz).
Remarkably, the comb rolls over without actually rolling! So the comb basically goes from point A to point B without occupying the space in between.
Can you envision yourself moving from one place to another without really moving?
Beam me up scotty!

Pieter Janssens

Inevitable suicide.

During his studies on Caernorhabditis elegans, Sulston observed that some cells die during the larval development, from 1090 somatic cells in the larval stage to 959 in the adult hermaphrodite. This phenomenon is called Apoptosis in which the cell nucleus becomes condensed, the cell itself shrivels and the shrunken corps is rapidly engulfed and digested by neighboring cells. Apoptosis, or programmed cell death, is a highly regulated process that allows a cell to self-degrade in order for the body to eliminate unwanted or dysfunctional cells. Normal cell deaths are thought to be “suicides” in which the cell activates a death programme and kills itself, which is very essential in generating an individual with the right cell types in the right numbers and places as evidenced by loss of tail by the tadpoles during frog metamorphosis and shaping of human limbs where cells in the hands die creating the gaps between the fingers and toes. Unlike necrosis, where the cell dies by swelling and bursting its content in the area, which causes an inflammatory response, apoptosis is a very clean and controlled process where the content of the cell is kept strictly within the cell membrane as it is degraded. Programmed cell death is a regular feature of normal animal development and is probably the fate of a substantial fraction of cells produced in most animals including me and you.

How to catch a criminal?

Glass fragments, often found at crime scenes, can be used as physical evidence to prove contact between the suspect and the victim.
Although glass cannot be distinguished by the observation of appearance, discrimination is possible by knowledge of elemental composition.
Amounts of trace elements are not controlled during the manufacturing process, so each type of glass has a unique elemental composition.
The work of a chemist consists of finding a technique which can determine the exact amount of the different trace elements present in the fragments.
Most of the techniques used cannot analyse solid materials, so the challenge is to find a good way to dissolve all types of glass.
Unfortunately, until today no universal technique has been found to do so for all types of glass.

Goudesone Frauke

TECHNOLOGY IN SPORTS

During the last years, the world of sports has been changing with the use of new technology applied to help the referees to take right decisions and minimize the mistakes in the development of different disciplines.
The use of cameras around the court of basketball in a country like the United States and the availability of instant video-replays help the referee to take a good decision knowing if a player are shooting within the time or not. The new technology is not being only used in basketball, it has been developed in others sports like cricket and tennis where the use of the Hawk-Eye technology helps to the referee to know if the ball goes out or it is in. But What is the Hawk-Eye? And How does it work? Are questions unknown for some people. It is a computer and television camera system linked (six or more cameras) which are around the court and traces the ball´s trajectory and sends it to a virtual-reality machine, so the referee and players can watch in a big screen of television if the decision is right or not.
Another sport loved for a big amount of people around the world in which are using new technology is the soccer in which the use of the Hawk-Eye technology in the United Kingdom by the introduction of goal-line sensors give a definitive decision when the ball crossed the line and there is a goal; however a new aim in soccer is the developing of a “Smart ball” which has a computer chip and with the help of a network of receivers around the field designed the precise position of the ball allowing to know exactly when it has passed the goal line.

The Aurorae

Scientific books say that an Aurora is produced when an ejection of solar mass collides with the North and South poles of the Earth’s magnetosphere, producing a diffuse but predominantly light projected in the Earth’s ionosphere.

In easy language we can say that the Sun spits particles continuously (some of them charged: protons and electrons) that are denomined Solar Wind, but sometimes there are significant eruptions that complement the wind. These eruptions have the main function of annoy: charged particles travelling at high speed (300-1000 km/s) bathing our expensive satellites… it can not be good for them. Actually it is the main problem they have; fortunatelly we and our beloved computers are under the comfortable atmosphere.

Back to the Aurorae, these particles traveling into the space feel a strong attraction towards the Earth, from the poles. When these particles come into the atmosphere some of them crash with some atoms and molecules (mainly oxigen and nitrogen), exciting them so fast that they emit a faint light before to came back their original state.

By Rodrigo Calvo Sein-Echaluce.