Article about Forensic Science

Spies could hide messages in gene-modified microbes

spies can now send messages hidden in genetically engineered bacteria. The new method, dubbed steganography by printed arrays of microbes (SPAM), uses a collection of Escherichia colistrains modified with fluorescent proteins that glow in a range of seven colours.
Every character of the message is encoded using two colours, creating 49 possible combinations. That is enough for the alphabet, the figures 0 to 9 and a few other symbols too. 
'Messages' are grown on agar plates then transferred to a thin film that can be sent in the post to the recipient. The film appears blank in everyday conditions, but the message is revealed when the recipient transfers the bacteria to an appropriate growth medium.
I find this really cool and interesting as now people can send secret messages without people finding out. They would not know what the message is saying until they put it in a specific place so the bacteria can grow. This would mean that people can now have messages that only the personal who knows how to 'unlock' can read it.

Reflection on Forensic science course

I have learnt a great deal from this course. Forensic science is mostly used to fight crime. I find this topic very interesting as it shows how people can track down criminals with such little things like fingerprints. This is possible because of the advancement of technology nowadays and because of the fact that every individual has different fingerprints and DNA. The fingerprints and DNA allows forensic scientists to track down the criminal. I have also learnt how easy it is to get caught if you are a criminal. There is always evidence and clues are left behind at the crime scene that are sometimes unnoticeable. An example is the 'Lefty Lewis' exercise. He left behind many clues for the police to track him and he did not even realise it. From this course i have also learnt how to identify different types of fingerprints. Everyone possesses a different set of fingerprints. There are lops, whorls, arches and composite fingerprints. Forensic scientist uses these to match the suspect.

Graded Activity 4: Fingerprints

This is the pie-chart I made with Excel. It is a pie-chart on the different types of fingerprints of the students of 1A1. From the chart, we can see that the number of composite fingerprints is 29 (10%). The number of arches is 34 (12%), the number of whorls is 68 (23%) and the number of loops is 159 (55%). I can see that students in 1A1 have the mot loops, followed by whorls, arches and least number of composites.

Graded Activity 3: Skeleton measurements

Simon's...
Humerus: 29.0cm
Radius: 22.5cm
Femur: 39.5cm
Tibia: 33.5cm


Theoretical height: 154.566cm
Actual height: 160cm




My...

Humerus: 33.5cm
Radius: 31.0cm
Femur: 46.0cm
Tibia: 42.0cm


Theoretical height: 184.867
Actual height: 186cm


The reason why there is discrepancies is because my body and Simon's body might not fulfil the golden ratio. The formulas given to calculate the theoretical height is based on the dimensions of he golden ratio.


My body does not fulfil the golden ratio. The golden ratio is 1.6 while my body proportion is 1.54

Graded Activity 2: Avatar making and description writing

 This is the Avatar of ME!












This is the avatar of Ronaldinho, a famous footballer.

While this is a real image of him.

Graded Activity 1: Lefty Lewis

1. Evidence that may have been left at the scene of the crime:

• Blood stain
• Leaked oil from car
• Torch that fell out from pocket
• Fingerprints
• Car Paint on the gate
• Muddy tyre tracks

2. Evidence that may have been taken away by Lewis:

• Jewellery
• mud on tyres

3. Suggestions for the forensic scientist?

• Test the fingerprints left behind to find out the theif
• Test the DNA of the blood stain on the curtain to find the theif
• Follow the trail of leaked oil to the thief's place
• The suspect's vehicle paint will be the same colour as the paint left on the gates

Separation Techques( examples)

Example of Some separation techniques are:

• Evaporation 
• Crystallization
• Distillation 
• Using a Separating Funnel 
• Fractional Distillation 
• Sublimation 
• Paper Chromatography 

These separation techniques are used separate mixtures. They are usually separated that way based on their different physical properties. An example would be separating a mixture of iron filings and water, Since iron filings are magnetic, we can use a magnet to draw the iron filings out of the mixture and the mixture can be separated.

ed.

Difference between a solution and a suspension

A solution is a mixture in which other substances (solutes) are dissolved.

• The components in a solution may not be separated from the solution by leaving it to stand, or by filtration

If a material dissolves in a liquid the material is said to be soluble. A solution is saturated if no more solute can be dissolved with temperature remaining constant. Examples

• salt in sea water

A suspension is a mixture of liquids with particles of a solid which may not dissolve in the liquid.

• The solid may be separated from the liquid by leaving it to stand, or by filtration

Examples

• sand in water

The blistering heat experienced by the US during August, as well as the June through August months, marks the second warmest summer on record, according to scientists at NOAA's National Climatic Data Center in Asheville, N.C. The average U.S. temperature in August was 75.7 degrees F, which is 3.0 degrees above the long-term (1901-2000) average, while the summertime temperature was 74.5 degrees F, which is 2.4 degrees above average. The warmest August on record for the contiguous United States was 75.8 degrees F in 1983, while its warmest summer on record at 74.6 degrees F occurred in 1936. Precipitation across the nation during August averaged 2.31 inches, 0.29 inches below the long-term average. The nationwide summer precipitation was 1.0 inch below average.


Many places in the world are getting warmer and warmer right now, not only the US. This is caused by all the pollution made by man and it is destroying the earth. temperatures are rising all over the globe. We should try to prevent this by excercising the three 'R's. Reduce, Reuse and Recycle. This will help to make earth a greener place. Using renewable energy also helps. Instead of emitting carbon monoxide, green energy is not only a resource that will not run out, but also, it can reduce the harmful gases emitted from cars. Practicing these will help stop global warming. 

Diffusion refers to the process by which molecules intermingle as a result of their kinetic energy of random motion. It describes the spread of particles through random motion from regions of higher concentration to regions of lower concentration. In diffusion, particles are propelled by thermal energy.


There is a special type of diffusion called osmosis. If two solutions of different concentration are separated by a semi-permeable membrane which is permeable to to the smaller solvent molecules but not to the larger solute molecules, then the solvent will tend to diffuse across the membrane from the less concentrated to the more concentrated solution. This process is called osmosis. Osmosis is of great importance in biological processes where the solvent is water. The transport of water and other molecules across biologicalmembranes is essential to many processes in living organisms. 

Save our Coral Reefs!

I have read a few articles on coral reefs and learnt that they are not faring well in recent decades. They faced multiple threats from pollution, disease, elevated water temperatures, and overfishing. Often referred to as the "rainforests of the Sea," coral reefs support a wide variety of marine life, help protect shorelines, and contribute significantly to tourism and the fishing industry.


There is a new study which looks at a rare but catastrophic impact on reefs: the damage caused by natural disasters such as an earthquakes.
In May of 2009, magnitude-7.3 earthquake shook the western Caribbean, causing lagoonal reefs in Belize to avalanche and slide into deeper water. This powerful earth destroyed half the number of coral reefs there. 


Another cause of the disappearance of coral reefs is pollution. Humans pollute the beach when they throw rubbish inti the sea and also when factories dump their waste products into the ocean.


I feel that we should help prevent the destruction of coral reefs by not polluting the ocean and shores. We should all do our best to save the "rainforests of the Sea".

Three states of matter

Matter is anything that has mass and takes up space. Anything around us and in the entire universe can be classified as either matter on energy.Matter is made up of tiny particles (Atoms & Molecules). 

Facts about matter:

• Particles of Matter are in constant motion.
• Particles of Matter are held together by very strong electric forces
• There are empty spaces between the particles of matter that are very large compared to the particles themselves.
• Each substance has unique particles that are different from the particles of other substances
• Temperature affects the speed of the particles.  The higher the temperature, the faster the speed of the particles.

Three different states of matter are:

1. Solid State Examples: rubber, iron, ice, chalk
2. Liquid State: Examples: alcohol, gasoline, oil, water
3. Gaseous State: Examples: air, natural gas, carbon dioxide, steam

Solids are closely packed together and are held in place by strong electrostatic forces. Particles of solids vibrate constantly due to their internal energy but they cannot move from one place to another.  Particles of solids possess only vibrational energy.

Liquids are kept together by forces of attraction that are weaker than those of solid particles.  The particles move around and slide over each other randomly. This type of energy is called translational    energy.  This energy gives a liquid  the ability to flow and be poured and to spread when a liquid is spilled.  Liquid particles also have vibrational energy.

The forces of attraction that hold Gases together are very weak and that the spaces between them are much larger than the spaces between solid and liquid particles. The particles of a gas move around more quickly than liquids and vibrate at the same time. This explains why they can escape from a container very easily and they can put pressure on the side of the container (example a balloon or a tire).

What are enzymes in the digestive system?

I have learnt about the digestive system in school but I was still unsure about the part on enzymes so i went online and read a little on it. I found out that digestive enzymes are enzymes that break down food into their simpler substances, in order to facilitate their absorption by the body. Digestive enzymes are diverse and are found in the saliva secreted by the salivary glands, hydrul in the stomach secreted by cells lining the stomach, in the pancreatic juice secreted by pancreatic exocrine cells, and in the intestinal (small and large) secretions, or as part of the lining of the gastrointestinal tract. 

Digestive enzymes are classified based on their target substrates:

• proteases and peptidases split proteins into amino acids.
• lipases split fat in three fatty acids and a glycerol molecule.
• carbohydrases split carbohydrates such as starch and sugars into simple sugars such as glucose, the simplest sugar on earth.
• nucleases split nucleic acids into nucleotides.

Planet blasted by stars

I have read that new data from NASA's Chandra X-ray Observatory and the European Southern Observatory's Very Large Telescope suggest that high-energy radiation is evaporating about 5 million tons of matter from the planet every second! I feel that this is very interesting because that is a lot of matter evaporated from that planet! The planet, known as CoRoT-2b, has a mass about 3 times that of Jupiter (1000 times that of Earth) and orbits its parent star, CoRoT-2a at a distance roughly ten times the distance between Earth and the Moon. If it wasn't for the planet, this star might have left behind the volatility of its youth millions of years ago. This is really cool. Imagine if a planet in our solar system is being fried like what is happening to CoRoT-2b. the heat would be excruciating and neighboring planets will also be affected one way or another. I am fascinated by this article. 

About 10 percent of the population  suffer from tinnitus. It is a constant, often high-pitched ringing or buzzing in the ears that can be annoying and even maddening, and has no cure. However Neuroscientists at the University of California, Berkeley are studying several new strategies for alleviating the problem. In experiments on rats, researchers have shown that tinnitus results from decreased inhibition in the auditory cortex. Thus, training that boosts inhibition or drugs that increase the levels of inhibitory neurotransmitter may alleviate the symptoms.
I think their study of this is very beneficial to us. Those suffering from tinnitus can be cured so they do not have to bear with the ringing and buzzing inside their ear anymore. This study by the neuroscientists will definetly benefit us.

Interesting news article from Science Daily

Some creatures, such as sea urchins, can react to light even though they do not have eyes. Previous studies of sea urchins have shown that they have a large number of genes linked to the development of the retina, which is the light-sensitive tissue in the human eye. The research group behind the study showed that the sensory light structures seem to be located on the tip and base of the tube feet that are found all over the sea urchin's body and are used to move. 


I find this topic very interesting because I never knew that sea urchins could react to light. They even have genes that are linked to the development of the human retina. This allows us humans and the sea urchins to sense light around us. Having sensory light structures all over the body sounds amazing. It is like a 360 degree view of the things around you. 


A lot of interesting facts about animals have been discovered, however, there are many more interesting species to be found. I hope that researchers which discover more amazing facts about nature. 

Research on digestitive system( What's the use of pancreas in the body?)

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland, as well as an exocrine gland, secreting pancreatic juice containing digestive enzymes that pass to the small intestine. These enzymes help the further breakdown of the carbohydrates, protein, and fat in the chyme.

Reflections on Science lesson(Digestive system)

Today I learnt about the Human digestive system in class. The system is made up of several organs working together to form a specific function. These organs include, mouth, salivary gland, oesophagus, stomach, liver, gall bladder, pancreas, small intestine, large intestine, rectum and anus.


In the mouth, both physical and chemical digestion take place.  The teeth help break large food pieces while food is mixed with saliva produced by salivary glands which breaks down starch into maltose.


No digestion takes place in the oesophagus. Muscles in its wall contract and relax to produce a wave-like movement that pushes the food into the stomach. This is called peristalsis.


Both physical and chemical digestion take place in the stomach. The stomach can expand to take in various amounts of food and also contract to churn the food to mix it with gastric juice. Gastric juice is a type of digestive juice produced by the stomach lining and it contains hydrochloric acid and proteases.


The small intestine is where most chemical digestion and absorbtion of food takes place. Nutrients are absorbed from the food and then passed on to th large intestine.


The large intestine absorbs water from the food. Then the waste products will be stored in the rectum and then passed out through the anus.

What I have learnt about Paper chromatography

Paper chromatography is a technique for separating and identifying mixtures that are or can be colored, especially pigments. Paper chromatography is one method for testing the purity of compounds and identifying substances. Paper chromatography is a useful technique because it is relatively quick and requires small quantities of material. When a colored chemical sample is placed on a filter paper, the colors separate from the sample by placing one end of the paper in a solvent. The solvent diffuses up the paper, dissolving the various molecules in the sample according to the polarities of the molecules and the solvent. If the sample contains more than one color, that means it must have more than one kind of molecule. Because of the different chemical structures of each kind of molecule, the chances are very high that each molecule will have at least a slightly different polarity, giving each molecule a different solubility in the solvent. The unequal solubilities cause the various color molecules to leave solution at different places as the solvent continues to move up the paper. The more soluble a molecule is, the higher it will migrate up the paper.

Energy transformation

Transforming energy is when the energy changes into another form Energy in a system may be transformed so that it resides in a different state. Energy in many states may be used to do many varieties of physical work. Energy may be used in natural processes or machines, or else to provide some service to society (such as heat,light, or motion). For example, an internal combustion engine converts the potential chemical energy in gasoline and oxygen into heat, which is then transformed into the propulsive energy (kinetic energy that moves a vehicle). A solar cell converts solar radiation into electrical energy that can then be used to light a bulb or power a computer.

Elements

A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Some examples of elements include gold, iron, copper,carbon, silicon, mercury, sodium, calcium, hydrogen,nitrogen, chlorine, and neon. 
As of now, 118 elements have been identified. Of the 118 known elements, only the first 94 are believed to occur naturally on Earth. Of these naturally occurring elements, 80 are stable or essentially so, while the others are radioactive. Additional elements, of higher atomic numbers than those naturally occurring, have been produced technologically in recent decades as the products of nuclear reactions. The properties of the chemical elements are often summarized using the periodic table that organizes the elements by increasing atomic number into rows ("periods") in which the columns ("groups") share recurring ("periodic") physical and chemical properties. Its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869.

Cellular respiration

Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert energy from nutrients intoadenosine triphosphate (ATP), and then release waste products.  That energy is used for the essential processes of life.  
All living cells must carry out cellular respiration. It can be aerobic respiration in the presence of oxygen or anaerobic respiration. Aerobic respiration requires oxygen in order to generate energy (ATP). Although carbohydrates,fats, and proteins can all be processed and consumed as reactant, it is the preferred method.

The first step in cellular respiration in all living cells is glycolysis, which can take place without the presence of molecular oxygen. If oxygen is present in the cell, then the cell can subsequently take advantage of aerobic respiration via the TCA cycle to produce much more usable energy in the form of ATP than any anaerobic pathway. Nevertheless, the anaerobic pathways are important and are the sole source of ATP for many anaerobic bacteria. Eukaryotic cells also resort to anaerobic pathways if their oxygen supply is low. For example, when muscle cells are working very hard and exhaust their oxygen supply, they utilize the anaerobic pathway to lactic acid to continue to provide ATP for cell function.

Cells

The cell is the functional basic unit of life. It was discovered by Robert Hooke and is the functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. 
There are millions of different types of cells. In the body, there are brain cells, skin cells, liver cells, stomach cells, and the list goes on.  All of these cells have unique functions and features.  And all have some recognizable similarities.  All cells have a 'skin', called the cell membrane, protecting it from the outside environment.  The cell membrane regulates the movement of water, nutrients and wastes into and out of the cell.  Inside of the cell membrane are the working parts of the cell.  At the center of the cell is the cell nucleus.  The cell nucleus contains the cell's DNA, the genetic code that coordinates protein synthesis.  In addition to the nucleus, there are many organelles inside of the cell - small structures that help carry out the day-to-day operations of the cell. 

Difference between Plant and Animal cells

Both plant and animal cells are eukaryotic cells, i.e., they have complex structures but the structures of both types of cells have major differences.

• A Plant Cell has a cell wall while an Animal Cell does not.
• A Plant Cell has chloroplast while an Animal Cell does not.
• A Plant Cell has vacuole while a Animal Cell does not.

There is another major difference between plant and animal cells. While the plant cells turn carbon dioxide into sugar, it is the animal cells that break the sugar back down to carbon dioxide to make energy. This also reflects the cyclic functions of Nature and the interdependence of organisms through which Life on earth flourishes.

Mixtures and Compounds

What are Mixtures and Compounds?

• Mixtures are heterogeneous forms of matter. Mixtures are composed of variable proportions of molecules and atoms.
• Compounds are homogeneous forms of matter. Their constituent elements (atoms and/or ions) are always present in fixed proportions (1:1).

Examples of mixtures:

• • soil
  • ocean water and other solutions
  • air
  • the cytosol of a cell

  Examples of compounds:

  • water (H₂O)
  • table salt (NaCl)
  • sucrose (table sugar, C₁₂H₂₂O₁₁)

Properties of Mixtures

• The composition of a mixture is variable.
• Each of its components retains its characteristic properties.
• Its components are easily separated.

Properties of Compounds

• The relative proportions of the elements in a compound are fixed.
• The components of a compound do not retain their individual properties. Both sodium and chlorine are poisonous; their compound, table salt (NaCl) is absolutely essential to life.
• It takes large inputs of energy to separate the components of a compound.

Photosynthsis

    Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria. In plants, algae, and cyanobacteria, photosynthesis uses carbon dioxide and water, releasing oxygen as a waste product. Photosynthesis is vital for all aerobic life on Earth. In addition to maintaining normal levels of oxygen in the atmosphere, photosynthesis is the source of energy for nearly all life on earth, either directly, through primary production, or indirectly, as the ultimate source of the energy in their food.
    Photosynthetic organisms are photoautotrophs, which means that they are repositories of energy, they are able to synthesize food directly from carbon dioxide using energy from light. They accrue it as part of their potential energy.
    Humans cannot carry out photosynthesis as they do not have chloroplast in their cells. Chloroplast contains Chlorophyll which help photosynthetic organisms carry out photosynthesis.

Lab Safety Rules

1: No eating or drinking in the lab. This means no gum, cough drops, applying chapstick, chewing hair ends, holding a pencil in your mouth, nail-biting, etc.


2: Keep flame and flammable solutions far apart. Set up your classroom so that if a flame IS to be used, it is located far from the exit, so most students are closer to the exit. Have any open alcohol beakers far from the flame --- for instance on another workbench --- so some of the alcohol evaporates while the tool is brought to the flame.


3: Keep electrical equipment far from water. Keep areas around electrical equipment dry (aquaria excluded, of course!)


4:Clean spills from the outside IN. Apply paper towels over the spill, then, carefully starting from the outside, wipe in.


5: Use proper safety protection --- fume hood, goggles, gloves. NOTE that latex allergies can develop!


6: Always clean glassware before you use it to be sure that residues are cleaned away. Add at least some water first, before adding any liquid or solid solutes.
Be careful weighing out chemicals and reagents. Do NOT return excess materials to the stock container.


7: Check all waterbaths with a thermometer before putting your hand into the water.


 8: All sharps (needles, razors, pins, toothpicks) should be discarded in a sturdy container.


 9: Science and writing go hand-in-hand ; have students keep a proper laboratory notebook


10: Be Prepared

How to use a Bunsen Burner safely

The Bunsen burner is used in laboratories to heat things.  It is named after Robert Bunsen. In order to use it safely and appropriately, it is important to know the correct steps on how to set it up and operate it.  A Bunsen burner can produce 2 different types of flames:

• The "coolest" flame is a yellow / orange color.  It is never used to heat anything, only to show that the Bunsen burner is on.  It is called the luminous flame.
• The non-luminous flame is difficult to see in a well-lit room.  It is the most commonly used flame.

This is how to light a Bunsen Burner:

1. Check for safety - lab coat on, long hair tied back, safety glasses on, books and papers away from the flame, apparatus set up not too close to the edge of the table...
   
2. Look at the holes.  Check that the holes are closed.  The holes can be adjusted to let in more or less air by turning the collar
3. Light the Bunsen burner. Turn on the gas tap and press the igniter.  To turn the gas tap on, you must first push down, then turn the tap. This is a safety feature so the taps are not accidentally pushed open. The Bunsen burner should light after pressing the igniter a few times.
4. Adjust the flame by turning the collar so that you have the appropriate flame for the experiment ( the non-luminous flame). 
5. During the experiment, stay vigilant so that if a problem occurs, you are ready to turn off the flame quickly.  This means that you should not leave your table unattended.