The o-quinones, themselves, are colorless, however they react with other phenolic compounds and can self-polymerize to form compounds which produce the brown color associated with apple oxidation (Nicolas et al.). This oxidation process forms a thin brown layer on the exposed surface of the apple.
The rate of browning in different apple types is dependent on both the concentration of polyphenol oxidase and polyphenols within the apple (Nicolas et al.). Decreased levels of either component within the oxidation reaction can slow the browning process. Apples which exhibit slow browning are often specifically chosen by farmers and the food industry, leading to a genetic selection of fruits with lower or less active polyphenol oxidase and polyphenols (Nicolas et al.). The activity of polyphenol oxidase can also be perturbed by thermal denaturation via heating or by coating the exposed apple with ascorbic acid, thus lowering the pH (Nicolas et al.). Ascorbic acid…… [Read More]
al., 1993; Forman & Dickinson, 2003). Though nitric oxide is not involved in as many individual processes as hydrogen peroxide, or at least a lower number of processes have been identified in current research, its presence in too great an abundance can disrupt proper signaling and trigger alternative signaling pathways other than those normally utilized in redox signaling (Forman & Dickinson, 2003). These redox signaling pathways have the potential to promote the continued production of reactive oxygen species rather than contributing to the continued progression of the optimal redox signaling cascade, in which the production of O, H2O2, and other reactive oxygen species would be signaled to cease and normal intercellular environments would resume (Forman & Dickinson, 2003).
Research into the complexities of redox signaling in wound response and its implications for the healing process remains ongoing, and many current findings are still the product of a great deal…… [Read More]
It was used by Michael Faraday in the 1800s in his experiments on electromagnetism. Other inventors improved on the battery's original design and these improvements produced telegraphs and doorbells. Napoleon onaparte was so impressed with the invention that he recommended honors for Volta, including making him a count in 1810 (CIRL, Rubin, Scratch, Corrosion Doctors).
From this first and crude battery evolved electrochemistry, electromagnetism, and modern applications of electricity (CIRL, 2011; Rubin, 2011; Scratch, 2011; Corrosion Doctors, 2011). Even the defeated principles of Galvani on animal electricity served as the initiative to the development of electrophysiology and modern biology. From Volta's name came the unit of electromotive force, called volt, while from Galvani's name was coined the galvanometer, the instrument for detecting and measuring small electric currents (CIRL, Rubin, Scratch, Corrosion Doctors).
Significance and Influence during the Industrial Revolution
It is when power is cut off that ancient means of…… [Read More]
The energy it stores (?180 Wh kg?1) at an average voltage of 3.8 V is only a factor of 5 higher than that stored by the much older lead -- acid batteries. This may seem poor in the light of Moore's law in electronics (according to which memory capacity doubles every 18 months), but it still took a revolution in materials science to achieve it. Billions of lithium-ion cells are produced for portable electronics, but this is not sustainable as cobalt must be obtained from natural resources (it makes up 20 parts per million of Earth's crust). (Armand & Tarascon, 2008, p. 653).
Fu investigated the lithium-ion conductivities of glasses and glass-ceramics in the LI2O-AlO3-TiO2P2O5 system. Fu's samples revealed high conductivity, albeit when Abrahams and Hadzifejzovic similarly investigated the LI2O-AlO3-TiO2P2O5 glass and glass-ceramic systems, their findings revealed "a maximum room temperature conductivity of 3.98 x 10-6 S/cm in their crystallized…… [Read More]
Natural overburden includes silty clay, silty peat, and silty sand (CH2MHILL, p. 3-2). Overburden is generally thin, averaging 3 meters in most areas, but can go up to 9 meters at times (CH2MHILL, p. 3-2). Native soils primarily reside in areas of low topography.
This topography allows for constant movement and shifting of overburden. Rainy seasons create excessive water flows, which travel down slopes to the low-lying areas and into the waterways. These areas of low topography are of particular concern, as they tend to accumulate deposits of contaminants.
Groundwater and surface water in the area are altered by man-made structures placed by the mining company. ater travels through the area by means of the overburden and the bedrock. In the area of the main mine, water flows primarily through bedrock (CH2MHILL, p. 3-2).Groundwater flows in a generally southeasterly direction. ater flows towards the major waterways such as the Moira…… [Read More]
2005). The rules for deep-sea life are different than those for terrestrial species. Stratification plays an important role in species classification in vent environments. As the chimney grows in height the environment changes.
Tarasov and associates believe that deep-sea vents have a longer evolutionary history then shallow vents found closer to the surface. This is an important factor in understanding how hydrothermal vents are connected to early life on planet earth. Deep-sea hydrothermal vent communities represent a different phenomenon than shallow water vents. The chemical processes that take place in the deep-sea vent communities are very different from those in shallow areas. Shallow vent species receive light from the sun and more closely resemble terrestrial life forms. However, this is not so with deep-sea forms. Hydrothermal plumes are a rising column of hot water that can have sharp definitions in microhabitats. Similar species found inside the plume and outside of…… [Read More]
Pharmacokinetics explains the process by which a drug is absorbed, distributed, metabolized, and eliminated from the body. These processes are dependent on the amount of the drug administered, the method of administration (which affects the rate of absorption, biotransformation, and even excretion), and how the drug binds in the tissues. In essence, a drug's ability to transverse the cellular membranes depends on its solubility and molecular size and shape. The passive diffusion of the drug across cellular membranes depends on its lipid solubility as well as concentration gradients outside and inside the cellular membrane and the pH differences across the membrane. Active transport of the drug occurs when the drug is actually moved by components of the membrane. This can allow a drug move against concentration and electrochemical gradients but it requires energy, can be selective, and can be inhibited by similar molecules. The absorption rate is influenced…… [Read More]
Different Fuel Cell Technologies
U.S Department of Energy (2010) provides the description of different fuel cell technologies. The fuel cell technologies are differentiated according to their efficiency, operating temperatures, costs and application. The classifications are based on 6 major groups:
Alkaline fuel cell (AFC),
Phosphoric acid fuel cell (PAFC),
Solid oxide fuel cell (SOFC),
Molten carbonate fuel cell (MCFC),
Proton exchange membrane fuel cell (PEMFC);
Direct methanol fuel cell (DMFC).
Alkaline fuel cell (AFC)
The AFC generates electrical power using alkaline electrolyte KOH (potassium hydroxide) in water-based solution. The presence of hydroxyl ions within the electrolyte allows a circuit to extract electric energy. The illustration in Fig 2 reveals an alkaline fuel cell. As being revealed in Fig 2, two hydrogen gas molecules combines with 4 hydroxyl ions have a negative charge to release 4 electrons and 4 water molecules. The equation 4 reveals the reaction of oxidation that takes…… [Read More]
THE CACAO TREE (THEOBROMA CACAO)
WHAT IS IN THE COCOA BEAN?
MAKING AND EATING CHOCOLATE
State of the At of Cocoa
Is Cocoa good fo you?
Buden of Poof
CHOCOLATE AS A FAT
EFFECTS ON BLOOD LIPIDS
WHAT IS OK
CHOCOLATE AND HEALTH AND DISEASE
H. Immune Function
J. Othe Disodes
N. Dental Caies
K. Heat Health
Pacemakes and vitamin pills ae just among a few of millions of health poducts that ae sold daily aound the wold. But one of the most easily accessible of all is ight beneath ou noses: chocolate. Cocoa, the plant fom which chocolate is deived, has had a positive effect on today's society because of its active ole in daily health. The development and distibution of cocoa has had a positive effect on today's…… [Read More]
Physiological Effects of Endurance Training
Endurance training produces many physiological changes, both during training and after the training period is complete. These changes are biochemical and also involve changes in the cardio-pulmonary system. The correct way to perform endurance training has been a subject of controversy in recent years. There are many differences in training methods. These differences and the effects of endurance training will be the subject of this research. The jury is still out as to what constitutes the perfect duration and intensity of training program.
Studies have shown that a focused training program can increase maximum oxygen intake by 15-30% over a three-month period (7) and that can increase to 50% if the training is sustained for over 2 years. The body makes many metabolic adaptations as well. These adaptations drop rapidly in the first few weeks after training is stopped (1).
Duration and Intensity of Different…… [Read More]
Contaminants in Drinking Water and Wastewater and Effects on Environment
Drinking water and wastewater contamination pose a significant threat to the public health sector. The contaminants affect the society in various ways, including causing diseases, developmental and growth problems. The causes of the problem are identifiable and can be managed by using the most applicable strategies. As such, necessities for the adoption of strategies that will help identify the contributing factors, results and adopt effective strategies that will prevent and reduce waterway pollution. Therefore, the research provides analysis on the effects, studies, and recommendations appropriate in reducing drinking water and wastewater contamination.
A number of chemicals play a significant role in influencing human activities of the daily living. They enable the development of new technologies and improve the standards and quality of life. Because of the widespread use of technology, chemicals enter the environment. Although, it is unintentional in…… [Read More]
The primary organ that is accountable for regulating metabolism is the hypothalamus. The hypothalamus is situated on the brain stem and forms the floor and part of the lateral walls of the third ventricle of the cerebrum. The main functions of the hypothalamus is to control and integrate activities of the autonomic nervous system (ANS), production and regulation of feelings of rage and aggression, regulation of body temperature and regulation of food intake (Graham, 2005).
BM goes down with age and with the loss of lean body mass. Increased muscle mass and cardiovascular exercise can help to increase BM, even when the body is at rest. Measured in calories, metabolic rates vary with exertion, recent food ingestion, muscle exertion, environmental temperature, emotional state, body temperature, pregnancy, menstruation, level of thyroid hormones stress hormones (epinephrine and norepinephrine), fear and illness. The human body requires energy in order to stay alive…… [Read More]
This means that their operation is totally opposite in direction, in fact a rechargeable battery can act as both a voltaic cell and an electrolytic cell depending on whether it is discharging or being charged. It is also practical to use the same type of metal as electrodes in an electrolytic cell while in voltaic cells the electrodes must be of different metals.
Since sodium is too reactive to freely occur naturally it exists in the earth's crust in a number of varied compounds such as halite. It can also be found in the form of sodium chloride and brine which are plentiful sea water. These compounds can be obtained by trapping the sea water or brine, or by mining rock salt. In order to obtain pure sodium metal, electrolysis of molten sodium chloride is done. This is achieved by using the molten sodium chloride as the electrolyte in an…… [Read More]
This teatment, albeit, does not poduce 100% chitosan, but basically poduces a mixtue of 10-15% chitin plus 85-90% pue chitosan, called "pue CC." In the U.S., chitosan constitutes a mixtue of appoximately7% chitin plus appoximately 93% chitosan. Outside of cost-effectiveness, the biological effects of chitin poduced fom each souce appeas identical. "Chitosan oligosacchaides (CO) takes chitosan a big step futhe," Matsunaga (2007 explains. "When CC is ingested, a small amount of it is boken down into vey small molecula paticles by the enzymes of the body, thus poducing CO. CO can also be manufactued by using an enzymatic pocess" (Matsunaga, as cited in Levine, p. 1). The body moe eadily absobs CO, although CO contains less fibe than egula CC.
In Case Histoy 1: Low Pulmonay (Lung) Function, Matsunaga (Levine, 2007) teats his fist patient, also his fathe, with the administation of CC. Pevious teatments had yielded no esults…… [Read More]
Tea as an Antioxidant
Tea is an aromatic drink that is usually prepared by soaking or pouring water over plant products, typically the tea plant, but also may be infused with other dried herbs, roots, or extracts. After plain water, tea is consumed more than any other drink globally, including soft drinks. It has a slightly bitter, astringent flavor, sometimes floral, sometimes metallic, that people find enjoyable and often relaxing or, in some cases, medicinal (Martin, 2007). The consumption of tea is said to have a number of beneficial health effects based on the properties it has including antioxidants, flavinols, flavonoids, polyphenols, and catechins. The catechins, particularly, are known for anti-inflammatory and cellular detoxicity. In addition, these catechins have proven neuroprotective activities that can bond with cannabinoid receptors and suppress pain and nausea and provide a relaxing effect (Korte, G., et.al., 2010). Medical studies have also shown that green tea…… [Read More]
(1989). These researchers investigated skeletal muscle adaptations in response to acclimatization at high altitude. Samples of muscle extracted before reaching high altitude and after returning to sea-level showed that maximal activities of enzymes, such as those representative of beta-oxidation, were unchanged. However, after exposure to extremely high altitude hypoxic conditions, reductions were observed in succinic dehydrogenase, citrate synthetase and hexokinase. The findings of this study did not support the researchers' hypothesis that extremely hypoxic conditions elicit changes that are adaptive toward maximizing oxidative function at the intracellular level (Green et al., 1989).
Donoghue, S., Fatemian, M., Balanos, G.M., Crosby, A., Liu, C., O'Connor, D., Talbot, N.P., obbins, P.A. "Ventilatory Acclimatization in esponse to Very Small Changes in PO2 in Humans." Journal of Applied Physiology 98 (2005): 1587-91.
Green, H.J., Sutton, J.., Cymerman, A., Young, P.M., Houston, C.S. "Operation Everest II: Adaptations in Human Skeletal Muscle." Journal of Applied Physiology…… [Read More]
Iso-Electric Point and Iron Content in Iron Hydroxide Impregnated Aluminosilicate-Based Geopolymers
Rahil Abou Saleh
Dr. Kiril Hristovski
Iron hydroxide impregnated aluminosilicate-based geopolymers (Fe-ASG) is a novel water treatment media currently under development for simultaneous removal of arsenic and inorganic contaminants. The goal of this study was to determine whether varied iron contents impregnated aluminosilicate impacts the surface charge in different pH conditions. The study tests for media types of virgin and iron impregnated ASG diluted in potassium nitrate (KNO3) for charge dispersion. pH of the sample was gradually adjusted using potassium hydroxide (KOH) and nitric acid (HNO3). Results demonstrated no significant relationship between iron content impregnated ASG and iso electric point, which suggests that surface area properties impacts the relationship.
I am especially appreciative of the guidance, encouragement, and patience exuded by Dr. Hristovski throughout the duration of this research project. Also I would like to give special thanks to…… [Read More]
The word "ergogenic" means having a tendency to increase work. In the perspective or setting of sports, this term encompasses processes employed to enhance the production as well as the performance of physiological energy. Nutritional ergogenic aids can be defined as dietary and nutritive supplements that purportedly increase the level of performance beyond the expected levels under normal circumstances and conditions (Coleman). A supplement can be defined to be a substance that is added to the everyday diet of an individual in order to redress the balance of a nutritional deficiency. More often than not athletes anticipate that ergogenic aids will offer them an added or competitive advantage in their events as they uniformly do not aspire to lose. Taking into the consideration the fact that sporting races and competing events are won by small differences and disparity of as little as one hundredth of a second, it…… [Read More]
Drugs thought to enhance serotonin-mediated neurotransmission have been shown to diminish appetite for carbohydrates. In a study done by Heraief, Burckhardt, Wurtman and Wurtman, (1985), they examined the ability of tryptophan (TP), serotonin's amino acid precursor, or a placebo to influence weight loss among 62 obese Swiss outpatients who were on a reducing diet known as the Protein-Sparing Modified Fast (PSMF) Diet which is often associated with severe carbohydrate craving. This diet provided relatively large amounts of protein but little carbohydrates, thus stimulating ketone body production. Its consumption also reduced the ratio of plasma TP to the summed concentrations of the other large neutral amino acids, thereby probably diminishing brain TP and serotonin levels. It was found that among moderately obese patients the TP significantly enhanced weight loss, especially during the first treatment month but also during the total. The TP didn't modify the reported adherence to the PSMF diet.…… [Read More]
3). Selenide ions are being increasingly being used in photoelectrochemical cell applications (Lewis, 1995). Selenium compounds are also found in internal combustion exhaust, and have been positively associated with increased mortality rates in five of six American cities surveyed by (Topeka, Kansas was the exception; the other cities surveyed were Boston, St. Louis, Knoxville, Madison, and Steubenville) (Dockery, Laden and Schwartz, 2000). The combustion of coal combustion is responsible for between 62% (Medical and Biological Effects of Environmental Pollutants- Selenium, 1976) and 85% (Eimutis, Quill & inaldi, 1978) of harmful selenium emissions in the United States.
Furthermore, in combination with oxygen, selenium forms selenium dioxide, SeO2; the reaction of this oxide with water results in selenious acid, H2SeO3. Selenium also forms a variety of compounds in which the selenium atom bonds to both an oxygen and a halogen atom resulting in compounds such as selenium (VI) oxychloride, SeO2Cl2, which is…… [Read More]