https://www.youtube.com/watch?v=VPtKOrwf1h0

Biomarker

What is biomarker   

Biomarkers, or biological markers, are biological measures of some biological state or condition. And it can be defined as" a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes or pharmacological responses to a therapeutic intervention."

Biomarkers are generally used to perform a clinical assessment such as cholesterol level or blood pressure and are also used to monitor and predict health states in individuals or across populations.

The function of biomarker

A huge number of biomarkers are being used today. Many biological system such as the cardiovascular system, metabolic system or the immune system all has its own special biomarkers.

In medicine area, traceable substance can be a biomarker that is introduced into an organism as a means to examine organ function and other aspects of health. For instance, rubidium chloride is used as a radioactive isotope to evaluate perfusion of heart muscle. Biomarker can also be a substance of which the detection indicates a particular disease state.  For example, the presence of an antibody may indicate an infection. To be specific, a biomarker indicates a change in expression or state of a protein that correlates with the risk or progression of a disease, or with the susceptibility of the disease to a given treatment.

There are also some biomarkers that even can be based on measures of the electrical activity of the brain or volumetric measures of certain brain regions or saliva testing of natural metabolites, such as saliva nitrite, a surrogate marker for nitric oxide.

Biochemical biomarkers are frequently used in clinical trials where they are derived from bodily fluids that are easily available to the early phase researchers. A special kind of biomarker called an end phenotype has been used as a very useful way to finding genetic causes of diseases such as schizophrenia.

Another example of a commonly used biomarker in medicine is prostate-specific antigen (PSA) which   can be measured as a proxy of prostate size with rapid changes potentially indicating cancer.

In cell biology area, a biomarker can be a molecule that allows the detection and isolation of a particular cell type. For example, the protein Oct-4 is used as a biomarker to identify embryonic stem cells.

In genetics area, a biomarker can be a DNA sequence that causes disease or is associated with susceptibility to disease. And they also can be used to create genetic maps of whatever organism is being studied.

The assessment of biomarker
Biomarker is a very useful way for scientists and doctors to predict and monitor the health and disease. And it can be used alone or in combination to assess the health or disease state of an individual. And in many scientific fields, the biomarkers are playing an indispensable part in the biological process.  

REFERENCES

http://en.wikipedia.org/wiki/Biomarker

http://www.news-medical.net/health/Biomarker-What-is-a-Biomarker.aspx

Bioindicators

A bioindicator is a living organism that has the capability of providing information regarding the health of the ecosystem. These organisms are highly sensitive towards pollution in the environment and can change in its outward appearance, behaviour and its biochemical functions or may also be unable to survive.

Bioindicators vary in species and can be animals, microorganisms or even plants. The purpose of bioindicators are to detect if there is pollution in the area, such as toxins. The presence of toxins can affect the growth of certain plants, causing the depletion in food of animals in that area and it is a tell-tale sign that there is pollution in the area. Eutrophication is also an indication of pollution as it could mean there are large amount of nitrates and phosphorus in the waters.

There are of course, both pros and cons of using bioindicators to detect pollution.

Using bioindicators allow us to detect pollution at a possibly earlier stage so that preventive measures can be taken as soon as possible to prevent further spreading of such pollution. However, we have adversely caused the death of these species that are used as bioindicators and this can potentially endanger them. 

REFERENCES

Bioindicators definition & examples: http://sciencelearn.org.nz/Contexts/Enviro-imprints/Science-Ideas-and-Concepts/Bioindicators

Frog picture: http://www.savethefrogs.com/amphibians/images/Litoria-chloris-calling-2-a.JPG

Starfish picture: http://www.vliz.be/v/images/thumb/0/0d/Starfish.jpg/400px-Starfish.jpg

Biosensor

Biosensor is an analytical device consisting of biological sensor like enzyme, antibody and a signal transducer. It converts the biological response into an electrical signal. The transducer are things like oxygen electrode, thermistor, pH electrodes and many more. 

http://www.ied.edu.hk/biotech/eng/classrm/class_gene5.html

Different types of biosensor include:

-       -Thermal Biosensor

-       -Optical biosensor

-       -Ion-sensitive biosensor

-       -Electrochemical biosensor

Application of biosensor: (Glucose monitoring biosensor)

Glucometer consist of glucose oxidase, this enzyme reacts with glucose in the blood droplet when pricked. This reaction between glucose oxidase and our blood creates a flux that generates an electrical signal. The glucometer is calibrated so that the strength of the electrical signal equals to the readings in the digital readout.

Pros and Cons of Biosensor:                                 

Pros:

-       -Rapid and continuous measurement.

-       -Very specific

-       -Less reagent used for calibration

-       -Quick response time

Cons:

-       -Cannot be steamed-sterilised

-       -Not feasible in sterile bioreactor operation

-       -Can be poisoned by compounds or metals

REFERENCES
http://www.ied.edu.hk/biotech/eng/classrm/class_gene5.html 
http://engineering.mit.edu/ask/how-do-glucometers-work 
http://www.azosensors.com/Article.aspx?ArticleID=402 

http://galleryhip.com/glucometer-clipart.html 

 What are the different types of pollution?

There are a few types of pollutions known to man and they are, air pollution, land pollution, water pollution, thermal pollution, noise pollution, personal pollution, light pollution, visual pollution and radioactive pollution but mainly air pollution, land pollution, water pollution, thermal pollution, noise pollution and radioactive pollution results in a large impact on animal and human life.

Air pollution is caused when harmful gases or small particles are released into the environment, causing detrimental health effects. When such gases or particles are inhaled by human, their health will be affected, showing signs of medical damage. Gases such as sulfur dioxide and nitrogen oxides not only pollutes the air but also causes acid rain which harms the environment even further. While gases such as carbon monoxide and methane causes global warming by excess greenhouse effect.

Land pollution refers to the pollution of soil which renders it useless for sustaining natural growth, be it for animals or plants. Land pollution is either caused deliberately or by accident for example landfills which is deliberate and sewage and toxic spill which are by accident.

Water pollution occurs when foreign harmful substances enter a clean source of water, reducing its purity and quality. An example of such would be fecal pollution where the water source is contaminated with disease carrying organisms which causes many diseases to the human who drinks the water, and as different water sources flow together, pollution can spread very quickly.

Thermal pollution is excess heat which generates negative effects for a long period of time. Power plants and factories produce heat in a large amount which is released to the environment, this causes the surrounding temperature to increase by a bit which accumulates to a large amount of heat in due time. This large amount of heat accumulated also contributes to global warming which is deadly to the whole of humanity.

Noise pollution is the high level of noise produced by a source which is not needed and not wanted. Noise sources are usually caused by human activity such as traffic, constructions and railroads. This may in time cause induced hearing loss and wildlife disturbance, causing a general impact on our lifestyle.

Radioactive pollution rarely occurs, but it is very deadly and difficult to remedy. It is usually caused from nuclear power plant accidental leakage or improper nuclear waste disposal. Radioactive pollution can cause birth defects, cancer and other health problems for human and wildlife populations. It can also pollute the soil and contribute to water and air pollution.

Pollutants?

Pollutants are mainly inorganic compounds, organic compounds, microorganisms and gaseous compounds. For example metals such as copper and lead, petrochemicals, Escherichia Coli and sulfur dioxide and methane. 

What is pollution?

Pollution is the entering of contaminants into the natural environment that results in unfavorable or undesired effects to living beings and the environment. Pollution comes in different forms such as chemical substances or energies like sound, light and heat. The pollutants which causes the pollution is either introduced to the source from the outside or it occurs naturally. https://www.youtube.com/watch?v=vP3pbh_-pu8 (pollution, land, air and water)

http://ocean.nationalgeographic.com/ocean/critical-issues-marine-pollution