2,115 research outputs found

    Colonic Protein Fermentation and Promotion of Colon Carcinogenesis by Thermolyzed Casein

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    Thermolyzed casein is known to promote the growth of aberrant crypt foci (ACF) and colon cancer when it is fed to rats that have been initiated with azoxymethane. We speculated that the promotion was a consequence of increased colonic protein fermentation (i.e., that the thermolysis of the casein decreases its digestibility, increases the amount of protein reaching the colon, and increases colonic protein fermentation and that the potentially toxic products of this fermentation promote colon carcinogenesis). We found that the thermolysis of casein reduces its digestibility and increases colonic protein fermentation, as assessed by fecal ammonium and urinary phenol, cresol, and indol-3-ol. Thermolysis of two other proteins, soy and egg white protein, also increases colonic protein fermentation with increased fecal ammonia and urinary phenols, and thermolysis of all three proteins increases the levels of ammonia and butyric, valeric, and i-valeric acids in the cecal contents. We found, however, that the increased protein fermentation observed with thermolysis is not associated with pro-motion of colon carcinogenesis. With casein, the kinetics of protein fermentation with increasing thermolysis time are clearly different from the kinetics of promotion of ACF growth. The formation of the fermentation products was highest when the protein was thermolyzed for one hour, whereas promotion was highest for protein that had been thermolyzed for two or more hours. With soy and egg white, thermolysis increased colonic protein fermentation but did not promote colon carcinogenesis. Thus, although thermolysis of dietary casein increases colonic protein fermentation, products of this fermentation do not appear to be responsible for the promotion of colon carcinogenesis. Indeed, the results suggest that protein fermentation products do not play an important role in colon cancer promotion

    (±)-trans-3-Oxo-1,2,3,4,4a,9,10,10a-octa­hydro­phenanthrene-10a-carboxylic acid: catemeric hydrogen bonding in a Ύ-keto acid

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    The title compound, C15H16O3, aggregates as hydrogen-bonded catemers progressing from each carboxyl to the ketone of a screw-related neighbor [O⋯O = 2.6675 (14) Å and O—H⋯O = 170°]. Two parallel centrosymmetrically related single-strand hydrogen-bonding helices proceed through the cell in the b-axis direction. The packing includes three inter­molecular C—H⋯O=C close contacts, involving both the ketone and the carboxyl group. The structure is isomorphous with that of the previously described Δ4 α,ÎČ-unsaturated ketone

    Utah’s Watershed Restoration Initiative: Restoring Watersheds at a Landscape Scale

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    Abstract: The Utah Watershed Restoration Initiative (WRI) is a partnership-based program, administered by the Utah Department of Natural Resources, which seeks to improve the functional capacity of high priority watersheds throughout the state. Since its inception in 2006, the WRI partnership has completed nearly 1,500 projects to restore and rehabilitate over 526,091 ha in Utah watersheds. The WRI program is unique to the west, in that it transcends jurisdictional boundaries, and local, state, and federal management authority to focus finite resources on completing high priority conservation projects. We surveyed selected WRI selected participants in 2015 to determine what factors they believed most contributed to the overall success of the program. Survey respondents attributed the success of the WRI program to: 1) engaged leadership at multiple levels, 2) a bottom-up hierarchy, 3) a history of collaboration, 4) practice partnerships, 5) a science-based approach, 6) operating at a meaningful spatial scale, 7) being solution minded, not problem focused, and 8) unselfish sharing of resources. In this paper we discuss these success factors and provide recommendations to those desiring to implement voluntary incentive-based landscape conservation strategies

    “Is it a slow day or a go day?”: The perceptions and applications of velocity-based training within elite strength and conditioning

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    Velocity-based training (VBT) is a contemporary prescriptive, programming, and testing tool commonly utilised in strength and conditioning (S&C). Over recent years, there has been an influx of peer-reviewed literature investigating several different applications (e.g. load-velocity profiling, velocity loss, load manipulation, and reliability of technology) of VBT. The procedures implemented in research, however, do not always reflect the practices within applied environments. The aim of this study, therefore, was to investigate the perceptions and applications of VBT within elite S&C to enhance contextual understanding and develop appropriate avenues of practitioner-focused research. Fourteen high-performance S&C coaches participated in semi-structured interviews to discuss their experiences of implementing VBT into their practices. Reflexive thematic analysis was adopted, following an inductive and realist approach. Three central organising themes emerged: Technology, applications, and reflections. Within these central themes, higher order themes consisting of drivers for buying technology; programming, testing, monitoring, and feedback; and benefits, drawbacks, and future uses also emerged. Practitioners reported varied drivers and applications of VBT, often being dictated by simplicity, environmental context, and personal preferences. Coaches perceived VBT to be a beneficial tool yet were cognizant of the drawbacks and challenges in certain settings. VBT is a flexible tool that can support and aid several aspects of S&C planning and delivery, with coaches valuing the impact it can have on training environments, objective prescriptions, tracking player readiness, and programme success.publishedVersio

    The Reliability and Validity of Current Technologies for Measuring Barbell Velocity in the Free-Weight Back Squat and Power Clean

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    This study investigated the inter-day and intra-device reliability, and criterion validity of six devices for measuring barbell velocity in the free-weight back squat and power clean. In total, 10 competitive weightlifters completed an initial one repetition maximum (1RM) assessment followed by three load-velocity profiles (40−100% 1RM) in both exercises on four separate occasions. Mean and peak velocity was measured simultaneously on each device and compared to 3D motion capture for all repetitions. Reliability was assessed via coefficient of variation (CV) and typical error (TE). Least products regression (LPR) (R2) and limits of agreement (LOA) assessed the validity of the devices. The Gymaware was the most reliable for both exercises (CV 10%; TE 0.11 m·s−1, except 100% 1RM (mean velocity) and 90‒100% 1RM (peak velocity)), with MyLift and PUSH following a similar trend. Poorer reliability was observed for Beast Sensor and Bar Sensei (CV = 5.1%‒119.9%; TE = 0.08‒0.48 m·s−1). The Gymaware was the most valid device, with small systematic bias and no proportional or fixed bias evident across both exercises (R2 > 0.42−0.99 LOA = −0.03−0.03 m·s−1). Comparable validity data was observed for MyLift in the back squat. Both PUSH devices produced some fixed and proportional bias, with Beast Sensor and Bar Sensei being the least valid devices across both exercises (R2 > 0.00−0.96, LOA = −0.36‒0.46 m·s−1). Linear position transducers and smartphone applications could be used to obtain velocity-based data, with inertial measurement units demonstrating poorer reliability and validity

    Transmission potential of Rift Valley fever virus over the course of the 2010 epidemic in South Africa.

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    A Rift Valley fever (RVF) epidemic affecting animals on domestic livestock farms was reported in South Africa during January-August 2010. The first cases occurred after heavy rainfall, and the virus subsequently spread countrywide. To determine the possible effect of environmental conditions and vaccination on RVF virus transmissibility, we estimated the effective reproduction number (Re) for the virus over the course of the epidemic by extending the Wallinga and Teunis algorithm with spatial information. Re reached its highest value in mid-February and fell below unity around mid-March, when vaccination coverage was 7.5%-45.7% and vector-suitable environmental conditions were maintained. The epidemic fade-out likely resulted first from the immunization of animals following natural infection or vaccination. The decline in vector-suitable environmental conditions from April onwards and further vaccination helped maintain Re below unity. Increased availability of vaccine use data would enable evaluation of the effect of RVF vaccination campaigns
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