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Synthesis of Cyclohexene via Dehydration of Cyclohexanol Procedure

Submitted by malberigi on Wed, 03/21/2018 - 15:02

Cyclohexanol (1.99 g, 19.8 mmol) was measured into a 5mL round-bottomed (rb) flask.  85% phosphoric acid (0.5 mL) was added to the rb flask.  The system was heated and the product was collected through fractional distillation.  The temperature plateau occurred at 64 °C and the product was obtained in a collection vial.  The product was transferred to a reaction tube.  The reaction tube was washed with water (1 mL).  The procedure was repeated with sodium hydroxide (1 mL) followed by saturated sodium chloride (1 mL).  The product was then dried with calcium chloride pellets (5 min).  The remaining product yielded (0.77 g, 47%).  The product was tested for the compounds it contained with infrared spectroscopy and gas chromatography (one peak) with a retention time (RT) of 0.435.  A bromine solution was added drop-wise to (0.5 mL) of the product and the prescence of cyclohexene was indicated by a color change of the bromine from reddish-orange to colorless.  A potassium permanganate reagent was added drop-wise to (0.3 mL) of the product and the presence of cyclohexene was indicated by a color change from purple to clear with a dark brown precipitate.  These tests were then compared to cyclohexane, which did not react with the reagents.

Highways Block Gene flow and Cause a Rapid Decline in Genetic Diversity of Desert Bighorn Sheep

Submitted by tedarling on Wed, 03/21/2018 - 14:49

What were the authors trying to test, and what predictions did they make?

The authors were trying to test the effects of road networks on genetic diversity and connectivity of populations. They predicted that roads and highways would reduce connectivity among populations of flora and fauna. The large number of roads is expected to hinder gene flow, and facilitate genetic drift. Under these conditions, species isolated by roads would likely lose genetic diversity. Population extinction rates are also expected to increase due to inbreeding and reduced evolutionary potential.

What, exactly, did the authors do?

    The authors studied 27 populations of desert bighorn sheep. Over three years genetic samples of the sheep were collected across the study area, primarily by means of fecal pellets. Fourteen different microsatellite loci were genotyped. Female dispersal rates were also studied by examining mitochondrial DNA. Female bighorn sheep are less likely to disperse, so maternally transmitted mitochondrial DNA was used to study dispersal rates.

What did the authors find (i.e, what were their data)?

    The authors found that “the amount of gene flow among populations was strongly and negatively correlated with barriers at interpopulation distances of less than 15 km.” Furthermore, gene flow was weakly and negatively correlated with barriers at distances between 15 and 30 km. The two variables were not correlated after distances of 30km. There was a low correlation of mitochondrial DNA diversity with both barriers and distance. Genetic simulations were also used, and showed that the genetic distance between populations could be influenced by barriers constructed only 40 years ago.

How did the authors interpret their findings?

The authors concluded that genetic diversity for bighorn sheep was negatively correlated with barriers, such as roads and highways. From the results, the authors estimate that genetic diversity had decreased by 15%, for populations completely isolated by barriers. The low correlation of mitochondrial DNA diversity with both barriers and distance may be due to low dispersal rates of the female sheep. Finally, the authors highlight the significance of their finding in a world with a rapidly increasing number of man made barriers “These results suggest that anthropogenic barriers constitute a severe threat to the persistence of naturally fragmented populations.” Underpasses and overpasses have been used successfully to aid in gene flow and help mitigate this issue.

 

Reaction

Submitted by lgiron on Wed, 03/21/2018 - 14:49

As many know, reaction time is the time that your brain can react to a stimulus. Three main stimulouses are visual, auditory, and tactile. The quickest reaction time of the three usually being tactile. A tactile stimulus this is the fastest is because we have many sensors on our body which enable us to react faster when we receive a stimulus compared to auditory and visual which both require more processing done by the brain. An examply of this is when we place our hand on a hot stove and almost immediately rectract our hand before serious damage can be done. Visual and auditory stimulous has a larger processing time than tactile because for each, you first need to recieve the stimulus and then the information has to be processed by the brain and differentiate between a danger stimulus or a regular stimulus. Reaction time is also influenced by many factors. Sleep could impact the reaction time of an individual. If an individual is not getting enough, their reaction time will decrease because their body is lacking awareness and energy needed for the reaction time. Stimulants such as caffeine or drugs that increase your alertness or heart rate will have the opposite of lack of sleep. These will increase your reaction time because it increases your alertness which makes you more susceptible to processing stimulus faster.

Synapse Paper Para 2

Submitted by nchenda on Wed, 03/21/2018 - 14:46

The system the authors use to answer the question is optogenetics. Optogenetics is when

one controls cells that have been injected with ion channels that respond to light. These ion channels are called light-sensitive ion channels. This system allows for gene disruption within the targeted cells in order to provide stimulus to the synaptic terminals to have dopamine released into them. While this is taking place scientists can then record the postsynaptic currents within the synapses that have dopamine in them. This can be specifically used to target the dopamine neurons in the dorsal striatum and nucleus accumbens. This can also target the cells in mice that do not have VGLUT2 in their neurons that still produce dopamine. VGLUT2 stands for vesicular glutamate transporters. They allow glutamate to be put into synaptic vesicles along with secretory vesicles. This is so that glutamate can be released into the synaptic terminals.

 

Embryonic Stem Cell Research Intro Pt. 2

Submitted by mkomtangi on Wed, 03/21/2018 - 14:39

Over thirty years ago the idea of stem-cell research was introduced to the scientific world, now thirty years later the research and the technology for stem cells has advanced tremendously. Stem cells have the amazing potential ability to develop into many different stem cells in the body, and due to its regenerative abilities stem cell research offers promises of disease treatment for diseases such as diabetes, spinal cord injury, Parkinson’s disease, and heart disease. However the true potential for stem cell research has not been fully reached, as obstacles regarding ethical permissibility, moral rights, and political justice have introduced controversy to the topic.

Anemia

Submitted by sworkman on Wed, 03/21/2018 - 14:23

Intrinsic hemolytic anemia develops when the red blood cells produced by your body are defective. This condition is often inherited, such as in people with sickle cell anemia or thalassemia. Some types of hemolytic anemia are hereditary-- specifically spherocytosis. This supports our diagnosis because the patient’s father also had occasional anemia. The hereditary spherocytosis is also more probable because the direct Coombs test was negative. Hemolytic anemias can have positive direct Coombs tests but hereditary spherocytosis would present a negative Coombs test. This negative test means that meaning fetus is not in danger and the mother has not developed antibiodies against fetus’s blood.

 

Discussion / final result of cyclohexanol lab

Submitted by michaelkim on Wed, 03/21/2018 - 11:21

By using phosphoric acid, dehydration of cyclohexanol was possible. Also, to determine if it was whether alkene or alkane, bromine was used to yield a trans- 1,2-dibrominated product. Oxidizing cyclic alkene to a dicarboxylic acid. Having used all the procedures done before this experiment such as finding melting points, densities, molecular weights, and more combination of extraction, distillation, recrystallization, chromatography was done. Chromatography displays how polluted it is with different liquids. It was about 85% cyclohexanol and 15% something else. In its cyclohexene at about 2900 and 1440, there was a scan done. Higher the temperature of the liquid was, the longer the compounds need which results in better separation. Exactly 2.02 grams of cyclohexanol was used and having to find % yield, different combinations of methods were used to recover. Boiling points were at 63 to 69 degrees as first drop occurred at 66 degrees. At the end, 0.313 grams were recovered which is about 15.5% recovered from the total 2.02 grams used. The second part of the experiment was with cyclohexene and cyclohexane. Depending on which liquid was used, the colors were changed. Bromine in dichloromethane and 1% potassium permanganate and 10% sulfuric acid were used. The only unaffected color was cyclohexene with bromine in dichloromethane. All the other three tested were affected. Using cyclohexene with potassium permanganate with sulfuric acid turned it dark purple. Cyclohexane made the two given liquids either reddish-orange (with bromine in dichloromethane) and dark purple (with 1% potassium permanganate and 10% sulfuric acid).

Week 9 Draft 4 Organic Extraction

Submitted by jngomez on Tue, 03/20/2018 - 23:26

Most basic of all procedures and involves purification of DNA. An important step within organic extraction is the removal of proteins. Can be done by extracting aqeous solutions of nucleic acids with phenol or chloroform. There are pros and cons when dealing with organic extraction. The pros are it yields relatively pure, high molecular weight DNA. In addition, DNA is double stranded. This means it is good for RFLP and PCR. The cons are it is time consuming and there is the increase risk of contamination. It also involves use of hazardous chemicals. 

 

Seed and feeder color preference in native New England bird species

Submitted by malberigi on Tue, 03/20/2018 - 22:22

Our research question involves seed color and feeder color discrimination in native New England bird species. We would like to test whether the color of the seed influences the rate at which it is consumed.  The same variety of seed would be used and colored via food dye, the different colors would then be placed in the same color feeder. These colors would include unnatural colors such as blue, pink, and purple and natural colors such as green, black, and red.  We would also include a control with no addition of color. We would also like to investigate as to whether the color of the feeder influences the frequency of visits. The same seed would be used in different color feeders and feeders would be observed for a set amount of time.  The feeder colors could be the same list of colors included previously and in place of the control would be clear/silver.  The preferences observed with both experiments in a natural environment can then be compared to that of an urban setting. This comparison may pose a developmental question as to how behavior is dictated by development of an individual in different environments.

Draft Results Part 2 Fruit Fly

Submitted by oringham on Tue, 03/20/2018 - 19:59

Figures 2-5 depict the amount of organisms in each vial by percent, separated by developmental stage. It is apparent that the control group yielded the highest percentage of pupae, at about 55%. Groups treated with precocene experienced a much lower percent yield of pupae, with 0.1 μM precocene yielding the lowest at 13.7%. The control yielded the lowest percentage of adults, at 30.6%, while 1 μM precocene yielded the highest percentage of adults at 55%. Most of the larval d. melanogaster were found in the 0.1 μM precocene group, with 45% of that group containing larvae. The control contained the least amount of larvae percentage, with only 14.3% making up that group.

 

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