3,311 research outputs found

    Premature Ovarian Insufficiency: Procreative Management and Preventive Strategies

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    Premature ovarian insufficiency (POI) is the loss of normal hormonal and reproductive function of ovaries in women before age 40 as the result of premature depletion of oocytes. The incidence of POI increases with age in reproductive-aged women, and it is highest in women by the age of 40 years. Reproductive function and the ability to have children is a defining factor in quality of life for many women. There are several methods of fertility preservation available to women with POI. Procreative management and preventive strategies for women with or at risk for POI are reviewed

    Variation in the flowering time orthologs BrFLC and BrSOC1 in a natural population of Brassica rapa.

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    Understanding the genetic basis of natural phenotypic variation is of great importance, particularly since selection can act on this variation to cause evolution. We examined expression and allelic variation in candidate flowering time loci in Brassica rapa plants derived from a natural population and showing a broad range in the timing of first flowering. The loci of interest were orthologs of the Arabidopsis genes FLC and SOC1 (BrFLC and BrSOC1, respectively), which in Arabidopsis play a central role in the flowering time regulatory network, with FLC repressing and SOC1 promoting flowering. In B. rapa, there are four copies of FLC and three of SOC1. Plants were grown in controlled conditions in the lab. Comparisons were made between plants that flowered the earliest and latest, with the difference in average flowering time between these groups ∼30 days. As expected, we found that total expression of BrSOC1 paralogs was significantly greater in early than in late flowering plants. Paralog-specific primers showed that expression was greater in early flowering plants in the BrSOC1 paralogs Br004928, Br00393 and Br009324, although the difference was not significant in Br009324. Thus expression of at least 2 of the 3 BrSOC1 orthologs is consistent with their predicted role in flowering time in this natural population. Sequences of the promoter regions of the BrSOC1 orthologs were variable, but there was no association between allelic variation at these loci and flowering time variation. For the BrFLC orthologs, expression varied over time, but did not differ between the early and late flowering plants. The coding regions, promoter regions and introns of these genes were generally invariant. Thus the BrFLC orthologs do not appear to influence flowering time in this population. Overall, the results suggest that even for a trait like flowering time that is controlled by a very well described genetic regulatory network, understanding the underlying genetic basis of natural variation in such a quantitative trait is challenging

    Caffeine and Sprint Performance in Habitual and Caffeine Naive Participants

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    Caffeine is thought to provide ergogenic benefits during endurance performance. However, there is limited research on the effects of caffeine on anaerobic sports performance. The purpose of this study was to examine the effects of 6 mg·kg-1 of caffeine on repeated sprint performance. The sample included active college students (N = 18), classified as habitual caffeine or caffeine naïve users. Participants completed a 12 x 30-m sprint test with 35 s rest intervals between sprints. Ratings of Perceived Exertion were collected every 3rd sprint. Height and body mass were measured and participants accommodated to the sprint test on Day 1. Participants were randomly assigned to the placebo or caffeine condition on Day 2 and the treatment was reversed on Day 3. Caffeine was ingested in a sports drink 1 h prior to performing the sprints. Caffeine produced a significantly faster best sprint time compared to the placebo trial, F (1, 17) = 7.38, MSE = .02, H-F p = .02. However, no significant difference was found between caffeine supplementation and placebo on time to complete the total sprint test. Additionally, no significant difference was found in sprint times with caffeine supplementation by sex or between caffeine-naïve and habitual caffeine users. Finally, a significantly higher average RPE was found with caffeine supplementation as compared to the placebo, t (1, 17) = 2.92, d = .38, p = .01. Caffeine has the potential to enhance sprint performance however, further research with women and habitual caffeine consumers is needed

    Analysis and Design of Wastewater Treatment

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    The work proposes the reuse of wastewater from the Faculty of Agronomic Engineering of the Technical University of Manabí, located in the Lodana parish in the city of Portoviejo, to irrigate the diversity of plantations that exist in the institution as a banana, cocoa and lemon. In the work, the results of the physical-chemical and bacteriological analysis carried out on the residual water generated in the institution are offered, being able to verify that it does not meet the parameters required to be used in the irrigation of crops. The technical scheme of the proposed treatment system is shown, specifying the structure of the zeolite filter. The calculations made for the technical and structural design of each of the devices that make up the proposed treatment system are provided. The analysis of the performance of the system that is illustrated with a series of data reflected in tables is exposed and where an efficiency between 84% and 88% can be verified. A review of compliance with environmental regulations is carried out and an economic analysis is provided on the cost of the investment for the introduction of the system in the Faculty of Agricultural Engineering of the Technical University of Manabí

    Acute Effects of Static and Proprioceptive Neuromuscular Facilitation Stretching on Agility Performance in Elite Youth Soccer Players

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    Int J Exerc Sci 5(2) : 97-105, 2012. A warm-up is an important part of preparation for a soccer match. Stretching is typically part of the warm-up however, debate exists as to the most appropriate type of stretching to perform. The purpose of this study was to examine the effects of static and proprioceptive neuromuscular facilitation (PNF) stretching on soccer-specific agility performance in 14 male elite, premier league youth soccer players. Participants completed 4 trials of the Balsom agility test while dribbling a soccer ball. Height, age, and body mass were collected in trial 1 and participants were accommodated to the agility test during trials 1 and 2. Trials 3 and 4 were the static and PNF treatment trials that were administered after a standardized warm-up (control) in a randomized and counterbalanced manner. There were no significant differences between the difference scores of the static and PNF stretching conditions, P = .66. Furthermore, no significant differences were found between the control and stretching trials for static stretching, P = .15 or between the control and stretching trials for PNF stretching, P = .58. Neither mode of stretching significantly affected agility performance. More research is needed to determine the chronic effects of PNF stretching on agility performance

    A High Frequency (HF) Inductive Power Transfer Circuit for High Temperature Applications Using SiC Schottky Diodes

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    Wireless sensors placed in high temperature environments, such as aircraft engines, are desirable to reduce the mass and complexity of routing wires. While communication with the sensors is straight forward, providing power wirelessly is still a challenge. This paper introduces an inductive wireless power transfer circuit incorporating SiC Schottky diodes and its operation from room temperature (25 C) to 500 C

    Quantitative Analysis of NF-κB Transactivation Specificity Using a Yeast-Based Functional Assay

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    The NF-κB transcription factor family plays a central role in innate immunity and inflammation processes and is frequently dysregulated in cancer. We developed an NF-κB functional assay in yeast to investigate the following issues: transactivation specificity of NF-κB proteins acting as homodimers or heterodimers; correlation between transactivation capacity and in vitro DNA binding measurements; impact of co-expressed interacting proteins or of small molecule inhibitors on NF-κB-dependent transactivation. Full-length p65 and p50 cDNAs were cloned into centromeric expression vectors under inducible GAL1 promoter in order to vary their expression levels. Since p50 lacks a transactivation domain (TAD), a chimeric construct containing the TAD derived from p65 was also generated (p50TAD) to address its binding and transactivation potential. The p50TAD and p65 had distinct transactivation specificities towards seventeen different κB response elements (κB-REs) where single nucleotide changes could greatly impact transactivation. For four κB-REs, results in yeast were predictive of transactivation potential measured in the human MCF7 cell lines treated with the NF-κB activator TNFα. Transactivation results in yeast correlated only partially with in vitro measured DNA binding affinities, suggesting that features other than strength of interaction with naked DNA affect transactivation, although factors such as chromatin context are kept constant in our isogenic yeast assay. The small molecules BAY11-7082 and ethyl-pyruvate as well as expressed IkBα protein acted as NF-κB inhibitors in yeast, more strongly towards p65. Thus, the yeast-based system can recapitulate NF-κB features found in human cells, thereby providing opportunities to address various NF-κB functions, interactions and chemical modulators

    Why do young adults in the United States have such low rates of organ donation registration?

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    The demand for transplantable organs has outpaced the supply. Thus, 20 Americans die every day while waiting for an organ. Although most adults support organ donation, 42% are not registered. The rate is even lower among young adults who are not enrolled in/never graduated from college. The aim of this study was to use the Integrated Behavior Model (IBM) to identify factors that predicted organ donation registration among a racially diverse sample of non-student young adults. The study was observational and cross-sectional. Proportional allocation was used to identify a racially diverse sample of 550 non-student, young adults from ten states in the U.S. with the lowest registration rates. A valid and reliable survey was designed, pilot-tested, and administered. A total of 407 young adults completed the survey (74%). Only 19% were registered donors. Caucasians were more likely to be registered donors than racial minorities, χ 2 (3, N = 407) = 15.19, p = 0.002. Those with more positive direct attitudes toward registration were 1.5 times more likely to be registered than those who had negative direct attitudes. Among non-registrants, indirect descriptive norm and direct attitude were statistically significant predictors of behavioral intention. Moreover, those who knew someone who donated an organ and knew someone who needed a transplant were nearly three times more likely to intend to register in the next year. The IBM proved useful in elucidating factors that predicted intention to register among non-student young adults. The IBM should be used by those who desire to increase registration rates

    Effect of Acute Antioxidant Consumption on Cardiac Baroreflex Sensitivity in Young Healthy Adults

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    There is an emerging body of evidence in animals indicating that elevated oxidative stress impairs baroreflex sensitivity (BRS) function, however studies in healthy humans have yielded equivocal results. One potential reason for this discrepancy is that previous studies have used individual antioxidant treatments (e.g., Vitamin C only) to investigate the effect of oxidative stress on BRS. Recent studies in healthy humans have demonstrated significant reductions in reactive oxygen species using an antioxidant cocktail (AOC; Vitamin C, Vitamin E, and Co-enzyme Q10) suggesting the effectiveness of this treatment. Whether this AOC induced reduction in oxidative species affects BRS in young, healthy adults remains unknown. PURPOSE: We tested the hypothesis that AOC will improve cardiac BRS in young healthy adults. METHODS: Five young men were studied on two separate days: placebo (sugar pills) and AOC (2000 mg Vitamin C, 150 IU Vitamin E and 100 mg Co-enzyme Q10) performed in random order. Resting heart rate (ECG) and arterial blood pressure (automated sphygmomanometer and finger photoplethysmography) were measured 90 minutes after AOC or placebo (a time period this AOC has been shown to have peak effects on oxidative stress). Spontaneous cardiac BRS was determined for all sequences combined (overall BRS), and also separately for up (increase systolic blood pressure: increase R-R interval) and down (decrease systolic blood pressure: decrease R-R interval) sequences. RESULTS: Systolic blood pressure on AOC day tended to be lower relative to the placebo day (127 ± 4 vs. 131 ± 5; p=0.098). However, no differences in overall cardiac BRS were found between placebo and AOC (18.0 ± 2.7 vs.17.3 ± 2.6 ms/mmHg; p=0.59). Likewise, up sequences (17.02 ± 2.9 vs 14.04 ± 4.0 ms/mmHg; p=0.51) and down sequences (18.0 ± 2.7 placebo vs. 18.0 ± 2.6 ms/mmHg AOC; p=0.98) were not different between conditions. Equal number of sequences were found between the placebo and AOC days. CONCLUSION: These preliminary data suggest that antioxidant treatment does not affect resting cardiac BRS in young, healthy men
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