"Many of us believe we are masters of own destiny, but new research is revealing the extent to which our behavior is influenced by our genes.
It's now possible to decipher our individual genetic code, the sequence of 3.2 billion DNA "letters" unique to each of us, that forms a blueprint for our brains and bodies.
This sequence reveals how much of our behavior has a hefty biological predisposition, meaning we might be skewed towards developing a particular attribute or characteristic. Research has shown genes may predispose not only our height, eye color or weight, but also our vulnerability to mental ill-health, longevity, intelligence and impulsivity. Such traits are, to varying degrees, written into our genes—sometimes thousands of genes working in concert.
Most of these genes instruct how our brain circuitry is laid down in the womb, and how it functions. We can now view a baby's brain as it is built, even 20 weeks before birth. Circuitry changes exist in their brains that strongly correlate with genes that predispose for autism spectrum disorder and attention deficit-hyperactivity disorder (ADHD). They even predispose for conditions that might not emerge for decades: bipolar disorder, major depressive disorder and schizophrenia."
Michigan State University and Stanford University scientists have invented a nanoparticle that eats away—from the inside out—portions of plaques that cause heart attacks.
Atherosclerosis is a cardiac-based disease where plaque builds up inside the body’s arteries, the blood vessels responsible for carrying oxygen-rich blood to the heart and other organs of the body. Plaque is made up of white immune blood cells, known as macrophages, fat, cholesterol, calcium, and other substances found in the blood. As this plaque hardens it narrows the arteries, limiting the flow of oxygen-rich blood around the body. This, in turn, can lead to serious problems, including heart attack, stroke, or even death.
The team states their nanoparticle reduces and stabilizes plaque, providing a potential treatment for atherosclerosis, a leading cause of death in the United States. The study is published in the journal Nature Nanotechnology.
Macrophages are a type of white blood cell in our immune system, which engulf and digest cellular debris, foreign substances, microbes, cancer cells, and anything else that does not have the type of proteins specific to healthy body cells.
Once inside the macrophages of arterial plaques, the nanoparticle delivers a drug agent that can stimulate the cell to engulf and eat cellular debris, removing the diseased/dead cells. By reinvigorating the macrophages, plaque size is reduced.
Future clinical trials on the nanoparticle are expected to reduce the risk of most types of heart attacks, with minimal side effects due to the unprecedented selectivity of the nanodrug, according to Smith. His research is focused on intercepting the signaling of the receptors in macrophages and sending a message via small molecules using Nano-immunotherapeutic platforms. Previous studies have acted on the surface of the cells, but this new approach works intracellularly and has been effective in stimulating macrophages.
"We found we could stimulate the macrophages to selectively eat dead and dying cells – these inflammatory cells are precursor cells to atherosclerosis – that are part of the cause of heart attacks," Smith said. "We could deliver a small molecule inside the macrophages to tell them to begin eating again."
This approach also has applications beyond atherosclerosis, he added.
"We were able to marry a groundbreaking finding in atherosclerosis by our collaborators with the state-of-the-art selectivity and delivery capabilities of our advanced nanomaterial platform," explained Smith. "We demonstrated the nanomaterials were able to selectively seek out and deliver a message to the very cells needed. It gives a particular energy to our future work, which will include clinical translation of these nanomaterials using large animal models and human tissue tests. We believe it is better than previous methods."
Smith has filed a provisional patent and will begin marketing it later this year.
What happens to the electric waves in our brain when we generate a linguistic expression without emitting any sound?
Language can also be present in the absence of sound, when we read or when we use words while thinking.
"The very fact that the majority of human communication takes place via waves may not be a casual fact; after all, waves constitute the purest system of communication since they transfer information from one entity to the other without changing the structure or the composition of the two entities. They travel through us and leave us intact, but they allow us to interpret the message borne by their momentary vibrations, provided that we have the key to decode it. It is not at all accidental that the term information is derived from the Latin root forma (shape): To inform is to share a shape.
In his “Philosophical Investigations,” Ludwig Wittgenstein asked: “Is it conceivable that people should never speak an audible language, but should nevertheless talk to themselves inwardly, in the imagination?” "
Electrodes on the brain have been used to translate brainwaves into words spoken by a computer – which could be useful in the future to help people who have lost the ability to speak.
When you speak, your brain sends signals from the motor cortex to the muscles in your jaw, lips and larynx to coordinate their movement and produce a sound.
“The brain translates the thoughts of what you want to say into movements of the vocal tract, and that’s what we’re trying to decode,” says Edward Chang at the University of California San Francisco (UCSF). He and his colleagues created a two-step process to decode those thoughts using an array of electrodes surgically placed onto the part of the brain that controls movement, and a computer simulation of a vocal tract to reproduce the sounds of speech.
The disease emergence model above provides a construct for how pathogens emerge from animals and illustrates the continuum of animal pathogen infectivity in the human population. However, relatively little is known about the factors that mediate transition from one stage to the next as a pathogen of animal origin scales the stages of this paradigm Figure1, ever increasing its ability to reside in the human population and be transmitted throughout it. What is known, however, is that the interface between humans and animals is of paramount importance in the process. As we increase our interactions with animals through hunting, the trading of animal foods, animal husbandry practices, wet markets, and the domestication of animals or exotic pets, the probability of cross-species transmission dramatically increases.
Zoonotic disease emergence model outlining the 5 stages of pathogen emergence from animals to humans.
What is the role played by information theory in biology? Is evolution driven by information? As it happens with physics, information is becoming more central to our understanding ecological complexity. A great review of ideas is here:https://bit.ly/2LjDBMk v/@ricard_sole
Communication is an important feature of the living world that mainstream biology fails to adequately deal with. Applying two main disciplines can be contemplated to fill in this gap: semiotics and information theory. Semiotics is a philosophical discipline mainly concerned with meaning; applying it to life already originated in biosemiotics. Information theory is a mathematical discipline coming from engineering which has literal communication as purpose. Biosemiotics and information theory are thus concerned with distinct and complementary possible meanings of the word ‘communication’. Since literal communication needs to be secured so as to enable semantics being communicated, information theory is a necessary prerequisite to biosemiotics. Moreover, heredity is a purely literal communication process of capital importance fully relevant to literal communication, hence to information theory. A short introduction to discrete information theory is proposed, which is centred on the concept of redundancy and its use in order to make sequences resilient to errors. Information theory has been an extremely active and fruitful domain of researches and the motor of the tremendous progress of communication engineering in the last decades. Its possible connections with semantics and linguistics are briefly considered. Its applications to biology are suggested especially as regards error-correcting codes which are mandatory for securing the conservation of genomes. Biology needs information theory so biologists and communication engineers should closely collaborate.
Both bacteria and viruses are so small that they can only be seen through a microscope, and both have the ability to cause infection, but that’s where the similarities end.
Bacteria
Bacteria are one-celled organisms that can be found naturally throughout our bodies and in our environment. Most are harmless and do not cause infection. Bacteria in our bodies help us to digest food, protect us against other bacteria or microbes, and provide nutrients for our body. Seen under a microscope they look like rods, balls, or spirals, and they can multiply quickly under the right conditions. Less than one per cent of bacteria actually make us sick. Infections caused by bacteria include strep throat, tuberculosis, and urinary tract infections (UTI).
Antibiotics are available to treat most bacterial infections; however, it is often best to let your body’s own immune system fight them if it is able to.
Viruses
Viruses on the other hand, cannot live without a host, or another living creature to help them multiply. Viruses are smaller than bacteria and they attach themselves to another living cell and use that cells' genetic material to reproduce themselves. Most viruses cause disease. Examples of diseases caused by viruses include the common cold, herpes, shingles, measles, chickenpox, COVID-19 and AIDS.
Antibiotics will not treat a viral infection. Viral infections require either vaccinations to prevent them in the first place or antiviral drugs to inhibit their development.
Viruses are tinier than bacteria. In fact, the largest virus is smaller than the smallest bacterium. All viruses have is a protein coat and a core of genetic material, either RNA or DNA. Unlike bacteria, viruses can't survive without a host. They can only reproduce by attaching themselves to cells. In most cases, they reprogram the cells to make new viruses until the cells burst and die. In other cases, they turn normal cells into malignant or cancerous cells.
Also unlike bacteria, most viruses do cause disease, and they're quite specific about the cells they attack. For example, certain viruses attack cells in the liver, respiratory system, or blood. In some cases, viruses target bacteria.
The nasal cavity refers to the interior of the nose or the structure which opens exteriorly at the nostrils. It is the entry point for inspired air and the first of a series of structures which form the respiratory system. The cavity is entirely lined by the nasal mucosa, one of the anatomical structures (others include skin, body encasements like the skull and non-nasal mucosae such as those of the vagina and bowel) which form the physical barriers of the body’s immune system. These barriers provide mechanical protection from the invasion of infectious and allergenic pathogens.
Humans can smell thousands—perhaps even millions—of different scents. Yet scientists know that in the nose, there are only about 400 different types of odour receptors—proteins that capture scented molecules so that smells can be identified. Thus, there isn’t, obviously, one type of receptor that responds to a rose, while another jumps for jasmine.
So how can we smell so much, with so few types of receptors?
The answer is that cells mix and match. Each nerve cell in the nose can sense more than one odour but picks up the smell to a different degree. An odour's unique signature depends on which cells respond to it, and how intensely.
What happens when you inhale a rose is that a group of cells is stimulated, and that group sends a combination of signals to the olfactory bulb—the site at the very front of the brain where smell perception takes place. This unique combination of signals tells the brain the odour is the smell of a rose.
What are the different types of cells in the nose
The epithelium of the nasal mucosa is of two types – respiratory epithelium, and olfactory epithelium differing according to its functions. In the respiratory region, it is columnar and ciliated. Interspersed among the columnar cells are goblet or mucin cells, while between their bases are found smaller pyramidal cells.
The average number of viral particles needed to establish infection is known as the infectious dose. We don’t know what this is for covid-19 yet, but given how rapidly the disease is spreading, it is likely to be relatively low – in the region of a few hundred or thousand particles, says Willem van Schaik at the University of Birmingham, UK.
Viral load, on the other hand, relates to the number of viral particles being carried by an infected individual and shed into their environment. “The viral load is a measure of how bright the fire is burning in an individual, whereas the infectious dose is the spark that gets that fire going,” says Edward Parker at the London School of Hygiene and Tropical Medicine.
If you have a high viral load, you are more likely to infect other people, because you may be shedding more virus particles. However, in the case of covid-19, it doesn’t necessarily follow that a higher viral load will lead to more severe symptoms.
For instance, health workers investigating the covid-19 outbreak in the Lombardy region of Italy looked at more than 5,000 infected people and found no difference in viral load between those with symptoms and those without. They reached this conclusion after tracing people who had been in contact with someone known to be infected with the coronavirus and testing them to see if they were also infected.
Similarly, when doctors at the Guangzhou Eighth People’s Hospital in China took repeated throat swabs from 94 covid-19 patients, starting on the day they became ill and finishing when they cleared the virus, they found no obvious difference in viral load between milder cases and those who developed more severe symptoms.
Although it is difficult to draw firm conclusions at this stage, such studies “may impact our assumptions about whether a high number of viral particles predisposes to a more serious disease”, says van Schaik.ring the "dose" of coronavirus one can get, and its connection to the severity of COVID-19
Some young healthcare workers with a serious disease -- a result of a big viral dose?
But three questions deserve particular attention because their answers could change the way we isolate, treat, and manage patients.
First, what we can learn from the "dose-response curve" for the initial infection --- that is, can we quantify the increase of the risk of infection as people are exposed to higher doses of the virus?
Second, there is a relationship between the initial "dose" of the virus and the severity of the disease - that is, does more exposure result in graver illness?
And third, are the quantitative measures of how the virus behaves in infected patients (e.g. the peak of your body's viral load, the patterns of its rise and fall) that predict the severity of their illness and how infectious they are to others?
So far, in the early phases of the COVID19 pandemic, we have been measuring the spread of the virus across people. As the pace of the pandemic escalates, we also need to start measuring the virus within people.
Viruses
are small obligate intracellular parasites which by definition
contain either a
RNA a or DNA genome, surrounded by a protective virus –
coded protein coat.Edward
Jenner (1798) introduced the term virus in
microbiology. Virus
Greek means ‘’ poison’’. In
1892 for the first time a
Russian botanist DMITRI IWANOWSKI discover the virus. They are infectious and cause various diseases to host organism. They come in different shapes. Based on the types of host cells or organisms, there are different types of viruses as plant viruses, animal viruses, bacteriophages, fungal viruses, protists viruses, etc. However, this article mainly focuses on the difference between plant virus and animal virus.
SHAPE
Viruses are of different shapes such as spherical or cuboid ( adenovirus),
Variable size
from 20 nm to 300 nm in diameter. They
are smallest than bacteria,
some are slightly larger than protein and nucleic
acid molecules and some are
about of the same size ( smallpox virus) as the
smallest bacterium and some
virus slightly large (300 – 400 nm).
HELICAL
( CYLINDRICAL) VIRUSES
The
helical viruses are elongated, rod-shaped, rigid or flexible. There the capsid is a hollow cylinder with a helical structure. Capsid
consists of monomers arranged helically in the rotational axis. The
consist may be naked e.g. TMV or envelope e.g. influenza virus.
POLYHEDRAL (ICOSAHEDRAL) VIRUSES
Polyhedral the structure has the three possible symmetries such as
tetrahedral, octahedral and
icosahedral.
The
viruses are more or less spherical, therefore icosahedral symmetry is
the best
one for packaging and bonding of subunits. The
cap Somers of each
face form an equatorial triangle and 12 intercepting point
or corners.
They
consist of naked capsid e.g. adenovirus or envelope e.g. herpes simplex virus.
COMPLEX
VIRUSES
The
viruses which have the unidentifiable capsids or have the capsids with
additional structures are called complex viruses. Capsids
not clearly identified
e.g. vaccinia virus etc. Capsids to which some other the structure is attached
e.g. some bacteriophages etc.
ENVELOPE There are certain plant and animal viruses and bacteriophage both
icosahedral and helical, which are surrounded by a thin membranous envelope.
This envelope is about 10-15 µm thick.
it is made up of protein, lipids and
carbohydrates. Which are combined to form
glycoprotein and lipoprotein? Lipids provide flexibility to the shape, therefore viruses look of variable
size and shape. The protein component of the envelope is of viral origin and
lipid and carbohydrate may be the feature of the host membrane.
The key difference between plant virus and the animal virus is that the plant virus is an intracellular parasite that infects plants while the animal virus is an intracellular parasite that infects animal tissues. Plant Viruses
Plant viruses, like other viruses, contain a core of either
DNA or RNA. You have already learned about one of these,
The tobacco mosaic virus. As plants have a cell wall to protect their cells, these viruses do not use receptor-mediated endocytosis to enter host cells as is seen with animal viruses. For many plant viruses to be transferred from plant to plant, damage to some of the plants’ cells must occur to allow the virus to enter a new host.
This damage is often caused by weather, insects, animals,
fire, or human activities like farming or landscaping. Additionally,
plant offspring may inherit viral diseases from parent plants.
Plant viruses can be transmitted by a variety of vectors,
through contact with an infected plant’s sap, by living organisms such as insects and nematodes, and through pollen.
When plants viruses are transferred between different plants,
this is known as horizontal transmission, and when they are
inherited from a parent, this is called vertical transmission.
Symptoms of viral diseases vary according to the virus and its host (see the table below). One common symptom is hyperplasia, the abnormal proliferation of cells that causes the appearance of plant tumours known as galls.
Other viruses induce hypoplasia, or decreased cell growth,
in the leaves of plants, causing thin, yellow areas to appear.
Still, other viruses affect the plant by directly killing plant cells,
a process is known as cell necrosis. Other symptoms of plant viruses
include malformed leaves, black streaks on the stems of the plants,
altered growth of stems, leaves, or fruits, and ring spots, which are
circular or linear areas of discolouration found in a leaf.
Plant viruses can seriously disrupt crop growth and development, significantly affecting our food supply. They are responsible for poor crop quality and quantity globally and can bring about huge economic losses annually. Others viruses may damage plants used in landscaping. Some viruses that infect agricultural food plants include the name of the plant they infect, such as tomato spotted wilt virus, bean common mosaic virus, and cucumber mosaic virus. In plants used for landscaping, two of the most common viruses are peony ring spot and rose mosaic virus. There are far too many plant viruses to discuss each in detail, but symptoms of bean common mosaic virus result in lowered bean production and stunted, unproductive plants. In the ornamental rose, the rose mosaic disease causes wavy yellow lines and coloured splotches on the leaves of the plant.
Animal Viruses
Animal viruses, unlike the viruses of plants and bacteria, do not
have to penetrate a cell wall to gain access to the host cell.
Non-enveloped or “naked” animal viruses may enter cells in two different ways. As a protein in the viral capsid binds to its receptor
on the host cell, the virus may be taken inside the cell via a
vesicle during the normal cell process of receptor-mediated
endocytosis. An alternative method of cell penetration used by non-enveloped viruses is for capsid proteins to undergo shape changes after binding to the receptor, creating channels in the host cell membrane. The viral genome is then “injected” into the host cell through these channels in a manner analogous to that used by many bacteriophages. Enveloped viruses also
have two ways of entering cells after binding to their receptors:
receptor-mediated endocytosis, or fusion. Many enveloped viruses enter the cell by receptor-mediated endocytosis in a
fashion similar to some non-enveloped viruses. On the other hand,
fusion only occurs with enveloped virions. These viruses, which include HIV among others, use special fusion proteins in their envelopes to cause the envelope to fuse with the plasma membrane of the cell, thus releasing the genome and capsid of the virus into the cell cytoplasm.
After
making their proteins and copying their genomes, animal viruses complete the
assembly of new viruses and exit the cell. As we have already discussed using
the example of HIV, enveloped animal viruses may bud from the cell the membrane
as they assemble themselves, taking a piece of
the
cell’s plasma membrane in the process. On the other hand, non-enveloped viral
progeny, such as rhinoviruses, accumulate in infected cells until there is a
signal for lysis or apoptosis and all viruses are released together. Animal
viruses are associated with a variety of human diseases.
Some of them follow the classic pattern of
acute disease, where symptoms get increasingly worse for a short period followed
by the elimination of the virus from the body by the immune system and eventual recovery from the infection.
Examples of acute viral
diseases
are the common cold and influenza. Other viruses cause long-term chronic
infections, such as the virus causing hepatitis C, whereas others, like herpes
simplex virus, only cause intermittent
symptoms. Still other viruses, such as human
herpesviruses 6 and 7, which in some cases can cause minor childhood disease
roseola, often successfully cause productive infections without causing any
symptoms
at all in the host, and thus we say these patients have an asymptomatic
infection.
In
hepatitis C infections, the virus grows and reproduces in liver cells, causing
low levels of liver damage.
The
damage is so low that infected individuals are often unaware that they are
infected, and many infections are detected only
by
routine blood work on patients with risk factors such as intravenous drug use. On the other hand, since
many of the symptoms
of viral diseases are caused by immune responses,
a lack of symptoms is an indication of a weak
immune response to the
virus. This allows the virus to escape elimination by the immune system and persist in individuals
for years, all the while producing low levels of progeny virions
in what is known
as a
chronic viral disease. Chronic infection of the liver by this
the
virus leads to a much greater chance of developing liver cancer,
sometimes
as much as 30 years after the initial infection.
As
already discussed, the herpes simplex virus can remain in a state of latency in
nervous tissue for months, even years.
As the
virus “hides” in the tissue and makes few if any viral proteins, there is
nothing for the immune response to act against, and immunity to the virus
slowly declines.
Under
certain conditions, including various types of physical and psychological
stress, the latent herpes simplex virus may be reactivated and undergo a lytic
replication cycle in the skin, causing the lesions associated with the disease.
Once
virions are produced in the skin and viral proteins are synthesized, the immune
response is again stimulated and resolves the skin lesions in a few days by
destroying viruses in the skin. As a result of this type of replicative cycle,
appearances of cold sores and genital herpes outbreaks only occur
intermittently,
even
though the viruses remain in the nervous tissue for life. Latent infections are
common with other herpesviruses as well, including the varicella-zoster virus
that causes chickenpox. Some animal-infecting viruses, including the hepatitis C
virus discussed above, are known as oncogenic viruses: They have the ability to
cause cancer. These viruses interfere with the normal regulation of the host
cell cycle either by
either
introducing genes that stimulate unregulated cell growth (oncogenes) or by
interfering with the expression of genes that inhibit cell growth. Oncogenic
viruses can be either DNA or RNA viruses.
Cancers
known to be associated with viral infections include cervical cancer caused by
human papillomavirus (HPV), liver cancer caused by hepatitis B virus, T-cell leukemia,
and several types of lymphoma. HPV, or human papillomavirus, has a naked
icosahedral capsid
visible
in this transmission electron micrograph and a double-stranded DNA genome that is
incorporated into the host DNA. The virus, which is sexually transmitted, is
oncogenic and can lead to cervical cancer.
What
are the Similarities Between Plant Virus and Animal Virus? Both plant virus and
animal virus are intracellular obligate parasites. They live within a host
cell. Moreover, they have either DNA or RNA genomes.Both types of viruses cause
various diseases.
Furthermore,
their genomes can either be single-stranded or double-stranded.
Also,
both can either be naked or enveloped.
What
is the Difference Between Plant Virus and Animal Virus?
