607 research outputs found
The Effects Of Vibration Exercise On Anaerobic Performance Using The Wingate Test
The aim of this study was to investigate whole-body vibration (WBV) and its effects on anaerobic performance using the Wingate test, specifically the changes in peak and mean power. Thirty five collegiate students completed three days of training in which they performed 3 different weighted exercises under vibratory or non-vibratory conditions. Participants then performed a Wingate. Two 2 x 2 mixed-design ANOVAs were used to examine the influence of the independent variables of sex, protocol, and order on peak and mean power output (SPSS 18.0; p ≤ 0.05). Results indicated a significant main effect of sex in regards to peak power output, as well as a main effect for sex regarding mean power output. These findings suggest that following an acute session of WBV, performance differences between sexes exist while performing lengthier anaerobic activities as assessed by using the Wingate test
The effects of polyphenol rich chocolate on cardiovascular risk and glycaemic control in type 2 diabetes mellitus
Background:Type 2 diabetes mellitus (T2DM) is characterised by increased rates of morbidity and mortality, much of which is related to cardiovascular disease. T2DM is considered to be a non-communicable disease, with its cause and aetiology linked to a number of genetic factors, which are influenced by dietary behaviours and lifestyle. Diet has a significant role to play in the prevention and management of T2DM. Both in vitro and in vivo studies suggest that plant flavanols may have beneficial effects for people with diabetes, including potentially those found in cocoa and chocolate. Cesar Fraga suggested in 2005 that perhaps we should eat more chocolate to prevent and manage diabetes, following a study of just 15 healthy individuals, which demonstrated improvements in insulin sensitivity and blood pressure. Despite this remark seven years ago, almost no work has been published outside of that presented in this thesis has investigated the effect of chocolate containing only its native flavanols (predominantly epicatechins) on glycaemic control and markers of cardiovascular risk in T2DM.Methodology:An exploratory review of the literature suggested that the effect of chocolate might be greater than that seen with cocoa. This thesis considered the published literature to ascertain whether chocolate provides greater efficacy over cocoa supplementation using a meta-analysis. This led into a series of clinical trials aimed at testing chocolate supplementation at levels which provide an adequate dose of flavanols without leading to excess energy or sugar intake. The first of the three studies consisted of a proof of concept study feeding 45g of chocolate over eight weeks in a double-blinded randomised crossover design (n=12). The second, using 13.5g again used a doubleblinded randomised crossover design to assess the acute effects of flavanols rich chocolate over a three-hour period in individuals with T2DM with an induced transient hyperglycaemia caused by a 75g oral glucose load (n=10). The final clinical trial was a three-arm randomised double-blinded parallel study aimed to investigate the effects over a 12-week period of milk chocolate enriched with flavanols in an attempt to maximise palatability.Results:The exploratory review with meta-analysis demonstrated that chocolate supplementation resulted in significantly greater reduction in blood pressure (both systolic and diastolic, sub-group analysis, p0.05). This effect was accompanied by a simultaneous reduction in urinary 15-F2t-isoprostane (a marker of oxidative stress). The final study using a milk chocolate and lower doses of epicatechin did not have an adverse effect on weight or glycaemia after 12 weeks, with participants actually gaining weight in the four weeks immediately after the completion of the study (p=0.002). No clear beneficial effects of any one chocolate were seen.Conclusion:The work in this thesis finally provides evidence to support Fraga’s suggestion, that there are benefits in terms of improved lipid profile and endothelial function with chocolate supplementation for individuals with T2DM. The equivocal results from the final study which used a chocolate containing about a third of the epicatechin dose of the first two studies, suggest that the dose required for benefit may be at least that accepted as being beneficial with respect of endothelial function (EFSA, 2012a) at200mg of flavanols in the general population for individuals with T2DM
Quality requirements for reclaimed/recycled water
Water used during current and previous space missions has been either carried or made aloft. Future human space endeavors will require some form of water reclamation and recycling. There is little experience in the U.S. space program with this technology. Water reclamation and recycling constitute engineering challenges of the broadest nature that will require an intensive research and development effort if this technology is to mature in time for practical use on the proposed U.S. Space Station. In order for this to happen, reclaimed/recycled water specifications will need to be devised to guide engineering development. Present NASA Potable Water Specifications are not applicable to reclaimed or recycled water. Adequate specifications for ensuring the quality of the reclaimed or recycled potable water system is reviewed, limitations of present water specifications are examined, world experience with potable water reclamation/recycling systems and systems analogs is reviewed, and an approach to developing pertinent biomedical water specifications for spacecraft is presented. Space Station water specifications should be designed to ensure the health of all likely spacecraft inhabitants including man, animals, and plants
Tall Oil Precursors in Sweetgum
Sweetgum is the major hardwood species being used by the kraft pulp industry of the southeastern United States. An accurate description of the diethyl ether extract is necessary to determine the quantity and quality of tall oil obtainable from this wood. The tall oil precursors content of fresh sweetgum sapwood was shown to be less than 0.2% on the oven-dried wood basis, about one-tenth the amount in southern pines. The proportion of neutrals was nearly six times larger than that found in pines; the major components were sitosterol and stigmastanol. The major components of the acids fraction were linoleic, linolenic, palmitic, oleic, and stearic acids; this is typical of hardwoods
Rapid Electrochemical Detection and Identification of Microbiological and Chemical Contaminants for Manned Spaceflight Project
Microbial control in the spacecraft environment is a daunting task, especially in the presence of human crew members. Currently, assessing the potential crew health risk associated with a microbial contamination event requires return of representative environmental samples that are analyzed in a ground-based laboratory. It is therefore not currently possible to quickly identify microbes during spaceflight. This project addresses the unmet need for spaceflight-compatible microbial identification technology. The electrochemical detection and identification platform is expected to provide a sensitive, specific, and rapid sample-to-answer capability for in-flight microbial monitoring that can distinguish between related microorganisms (pathogens and non-pathogens) as well as chemical contaminants. This will dramatically enhance our ability to monitor the spacecraft environment and the health risk to the crew. Further, the project is expected to eliminate the need for sample return while significantly reducing crew time required for detection of multiple targets. Initial work will focus on the optimization of bacterial detection and identification. The platform is designed to release nucleic acids (DNA and RNA) from microorganisms without the use of harmful chemicals. Bacterial DNA or RNA is captured by bacteria-specific probe molecules that are bound to a microelectrode, and that capture event can generate a small change in the electrical current (Lam, et al. 2012. Anal. Chem. 84(1): 21-5.). This current is measured, and a determination is made whether a given microbe is present in the sample analyzed. Chemical detection can be accomplished by directly applying a sample to the microelectrode and measuring the resulting current change. This rapid microbial and chemical detection device is designed to be a low-cost, low-power platform anticipated to be operated independently of an external power source, characteristics optimal for manned spaceflight and areas where power and computing resources are scarce
Aspartame in conjunction with carbohydrate reduces insulin levels during endurance exercise
Gold OAAs most sport drinks contain some form of non-nutritive sweetener (e.g. aspartame), and with the variation in blood glucose regulation and insulin secretion reportedly associated with aspartame, a further understanding of the effects on insulin and blood glucose regulation during exercise is warranted. Therefore, the aim of this preliminary study was to profile the insulin and blood glucose responses in healthy individuals after aspartame and carbohydrate ingestion during rest and exercise. Each participant completed four trials under the same conditions (45 min rest + 60 min self-paced intense exercise) differing only in their fluid intake: 1) carbohydrate (2% maltodextrin and 5% sucrose (C)); 2) 0.04% aspartame with 2% maltodextrin and 5% sucrose (CA)); 3) water (W); and 4) aspartame (0.04% aspartame with 2% maltodextrin (A)). Insulin levels dropped significantly for CA versus C alone (43%) between pre-exercise and 30 min, while W and A insulin levels did not differ between these time points. Aspartame with carbohydrate significantly lowered insulin levels during exercise versus carbohydrate alone.Peer Reviewe
Northern Great Plains Beef Production: Production and Marketing Practices of Cow-Calf Producers
Ruminant livestock production in North Dakota, South Dakota, Montana, and Wyoming is critical to the region's economy. Because of the economic significance of ruminant livestock production, producers in the four-state area are continually looking for opportunities to increase income and improve the viability of their farm and ranch operation. Accordingly, the Four-state Ruminant Consortium, an integrated research and extension program, was created to specifically address issues related to ruminant livestock production. One of the more widely applicable possibilities for adding value through the regions's ruminant livestock sector appears to be backgrounding feeder calves. However, while economic analysis has indicated that stockgrowers in the study area could typically increase their net returns by backgrounding feeder calves, anecdotal evidence suggests relatively few producers are presently backgrounding feeder calves. To identify the socioeconomic impediments inhibiting producers from backgrounding feeder cattle, this study sought to identify managerial, social, and institutional factors that influence and perhaps constrain producers' ability or willingness to background feeder cattle. Study objectives were to identify and document producers' current production and marketing practices as well as identify stock growers' perception of opportunities for and impediments to expansion of the ruminant livestock industry in the study area. A mail questionnaire was delivered to 5,270 livestock producers in 37 counties in the 4-state study area of southwestern North Dakota, northwestern South Dakota, southwestern Montana and northwestern Wyoming. The questionnaire was designed to solicit a wide variety of information about operators' current production practices, including marketing, backgrounding, retained ownership, herd management, and feed and forage practices. The questionnaire also solicited operators attitudes on a wide variety of issues related to opportunities for and impediments to the expansion of the ruminant livestock industry in the study area as well asking respondents to identify what types of information would be of most interest to them and in what form they would prefer that information be delivered. The questionnaire also collected basic demographic data. Findings from the mail questionnaire are detailed in this report.Backgrounding, Feeder calves, Beef cattle producer characteristics, Feeder cattle production practices, Beef cattle marketing, Livestock Production/Industries, Marketing,
Towards Fast Computation of Certified Robustness for ReLU Networks
Verifying the robustness property of a general Rectified Linear Unit (ReLU)
network is an NP-complete problem [Katz, Barrett, Dill, Julian and Kochenderfer
CAV17]. Although finding the exact minimum adversarial distortion is hard,
giving a certified lower bound of the minimum distortion is possible. Current
available methods of computing such a bound are either time-consuming or
delivering low quality bounds that are too loose to be useful. In this paper,
we exploit the special structure of ReLU networks and provide two
computationally efficient algorithms Fast-Lin and Fast-Lip that are able to
certify non-trivial lower bounds of minimum distortions, by bounding the ReLU
units with appropriate linear functions Fast-Lin, or by bounding the local
Lipschitz constant Fast-Lip. Experiments show that (1) our proposed methods
deliver bounds close to (the gap is 2-3X) exact minimum distortion found by
Reluplex in small MNIST networks while our algorithms are more than 10,000
times faster; (2) our methods deliver similar quality of bounds (the gap is
within 35% and usually around 10%; sometimes our bounds are even better) for
larger networks compared to the methods based on solving linear programming
problems but our algorithms are 33-14,000 times faster; (3) our method is
capable of solving large MNIST and CIFAR networks up to 7 layers with more than
10,000 neurons within tens of seconds on a single CPU core.
In addition, we show that, in fact, there is no polynomial time algorithm
that can approximately find the minimum adversarial distortion of a
ReLU network with a approximation ratio unless
=, where is the number of neurons in the network.Comment: Tsui-Wei Weng and Huan Zhang contributed equall
- …