8,034 research outputs found

    The cholesterol-raising diterpenes from coffee beans increase serum lipid transfer protein activity levels in humans

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    Cafestol and kahweol–diterpenes present in unfiltered coffee— strongly raise serum VLDL and LDL cholesterol and slightly reduce HDL cholesterol in humans. The mechanism of action is unknown. We determined whether the coffee diterpenes may affect lipoprotein metabolism via effects on lipid transfer proteins and lecithin:cholesterol acyltransferase in a randomized, double-blind cross-over study with 10 healthy male volunteers. Either cafestol (61–64 mg/day) or a mixture of cafestol (60 mg/day) and kahweol (48–54 mg/day) was given for 28 days. Serum activity levels of cholesterylester transfer protein, phospholipid transfer protein and lecithin:cholesterol acyltransferase were measured using exogenous substrate assays. Relative to baseline values, cafestol raised the mean (±S.D.) activity of cholesterylester transfer protein by 18±12% and of phospholipid transfer protein by 21±14% (both P<0.001). Relative to cafestol alone, kahweol had no significant additional effects. Lecithin:cholesterol acyltransferase activity was reduced by 11±12% by cafestol plus kahweol (P=0.02). It is concluded that the effects of coffee diterpenes on plasma lipoproteins may be connected with changes in serum activity levels of lipid transfer proteins

    Realization of a space reversal operator

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    In this paper we propose the realization of a bosonic-fermionic interaction in the context of trapped ions whose effect upon the ion center of mass degrees of freedom is properly speaking a spatial inversion. The physical system and its features are accurately described and some applications are briefly discussed.Comment: 9 pages; to appear in Rep. Math. Phys., in summer 200

    Mechanistic studies on the lipid-raising coffee diterpenes cafestol and kahweol in monkeys, mice and man

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    Cafestol and kahweol are lipid-raising diterpenes present in unfiltered coffee. The objective of this thesis was to study their lipid-raising action in man. Unravelling this action might lead to new insights into the regulation of serum cholesterol levels.We first studied the absorption and urinary excretion of cafestol and kahweol in eight ileostomy volunteers. About 70% of the consumed cafestol and kahweol was absorbed and thus available for raising serum lipids in humans. Only 1.2% of the diterpenes was subsequently excreted as a conjugate of glucuronic acid or sulphate in urine, suggestive for an extensive metabolism of coffee diterpenes.We then searched for an animal model to study the mechanism of action of cafestol and kahweol. In African green monkeys, both diterpenes raised total cholesterol less pronounced than in man. Unlike humans, the rise in cholesterol was predominantly due to a rise in HDL cholesterol rather than LDL cholesterol. In apolipoprotein E*3-Leiden mice, cafestol and kahweol increased total cholesterol with 61% after eight weeks of treatment. The increase in total cholesterol was mainly due to a rise in VLDL and IDL cholesterol. After three weeks of treatment, total cholesterol was increased due to suppression of bile acid synthesis, which caused a decreased expression of the LDL receptor. In addition, VLDL became enriched in cholesteryl esters.Two mechanistic studies were performed in healthy human subjects. Consumption of cafetiere (French-press) coffee increased CETP activity by 15% after 12 weeks of intervention. The increase in CETP activity clearly preceded the increase in LDL cholesterol. Cafestol increased serum triglycerides by an 80% increase in the production rate of VLDL 1 apolipoprotein B after two weeks of intervention. This resulted in an increased amount of VLDL 1 particles in the circulation. Cafestol did not change the composition of VLDL 1 . VLDL 2 became enriched with cholesteryl esters.In conclusion, cafestol first increases plasma triglycerides by increasing the production rate of VLDL 1 apolipoprotein B. The subsequent rise in LDL cholesterol might be due to suppression of bile acid synthesis, which probably leads to down-regulation of the LDL receptor and/or to an enrichment of VLDL 2 with cholesteryl esters. The mechanisms of action that raise plasma cholesterol and plasma triglycerides in humans might be regulated independently in the liver.</p

    Cannibalism as a life boat mechanism

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    Under certain conditions a cannibalistic population can survive when food for the adults is too scarce to support a non-cannibalistic population. Cannibalism can have this lifeboat effect if (i) the juveniles feed on a resource inaccessible to the adults; and (ii) the adults are cannibalistic and thus incorporate indirectly the inaccessible resource. Using a simple model we conclude that the mechanism works when, at low population densities, the average yield, in terms of new offspring, due to the energy provided by one cannibalized juvenile is larger than one

    Accurate ab initio density fitting for multiconfigurational self-consistent field methods

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    Using Cholesky decomposition and density fitting to approximate the electron repulsion integrals, an implementation of the complete active space self-consistent field (CASSCF) method suitable for large-scale applications is presented. Sample calculations on benzene, diaquo-tetra-μ-acetato-dicopper(II), and diuraniumendofullerene demonstrate that the Cholesky and density fitting approximations allow larger basis sets and larger systems to be treated at the CASSCF level of theory with controllable accuracy. While strict error control is an inherent property of the Cholesky approximation, errors arising from the density fitting approach are managed by using a recently proposed class of auxiliary basis sets constructed from Cholesky decomposition of the atomic electron repulsion [email protected]

    An Analysis of Confidence Levels in Athletic Training Students during the Coronavirus Pandemic

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    International Journal of Exercise Science 16(3): 1284-1292, 2023. Background: The COVID-19 pandemic created a challenge to athletic training students, with many classes converted to online education, and many clinical experiences interrupted. These changes may have negatively affected the confidence level of athletic training students in their athletic training skills. Purpose: To determine if athletic training students’ educational experiences during the COVID-19 pandemic have impacted their confidence levels in completing athletic training skills. Procedures: A cross-sectional design using an online survey of 56 athletic training students from 33 CAATE accredited athletic training programs was used. The survey consisted of questions about the percentage of online learning, didactically and clinically, during the pandemic and confidence levels for skills within the five athletic training domains. Descriptive statistics were calculated, and factorial ANOVAs were used to analyze the level of confidence by semester of clinical experience. Main Findings: Factorial ANOVA demonstrated lower perceived confidence levels for students who had more online clinical experience for the following domains: injury and illness prevention and wellness promotion, therapeutic intervention, and healthcare administration and professional responsibility. Confidence was also lower in correctly performing the clinical skills for evaluating spine and torso, developing and implementing a rehabilitation program for the lower extremity, and developing and implementing a rehabilitation program for the back. Principal Conclusion: Athletic training students who had large portion of their clinical and classroom experience online had perceived lower levels of confidence in performing clinical and administrative skills. Online learning may influence athletic training students’ confidence level in performing athletic training skills

    Implementation conditions for diet and physical activity interventions and policies : an umbrella review

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    BACKGROUND: This umbrella review aimed at identifying evidence-based conditions important for successful implementation of interventions and policies promoting a healthy diet, physical activity (PA), and a reduction in sedentary behaviors (SB). In particular, we examined if the implementation conditions identified were intervention-specific or policy-specific. This study was undertaken as part of the DEterminants of DIet and Physical Activity (DEDIPAC) Knowledge Hub, a joint action as part of the European Joint Programming Initiative a Healthy Diet for a Healthy Life. METHODS: A systematic review of reviews and stakeholder documents was conducted. Data from nine scientific literature databases were analyzed (95 documents met the inclusion criteria). Additionally, published documentation of eight major stakeholders (e.g., World Health Organization) were systematically searched (17 documents met the inclusion criteria). The RE-AIM framework was used to categorize elicited conditions. Across the implementation conditions 25 % were identified in at least four documents and were subsequently classified as having obtained sufficient support. RESULTS: We identified 312 potential conditions relevant for successful implementation; 83 of these received sufficient support. Using the RE-AIM framework eight implementation conditions that obtained support referred to the reach in the target population; five addressed efficacy of implementation processes; 24 concerned adoption by the target staff, setting, or institutions; 43 referred to consistency, costs, and adaptations made in the implementation process; three addressed maintenance of effects over time. The vast majority of implementation conditions (87.9 %; 73 of 83) were supported by documents referring to both interventions and policies. There were seven policy-specific implementation conditions, which focused on increasing complexities of coexisting policies/legal instruments and their consequences for implementation, as well as politicians' collaboration in implementation. CONCLUSIONS: The use of the proposed list of 83 conditions for successful implementation may enhance the implementation of interventions and policies which pursue identification of the most successful actions aimed at improving diet, PA and reducing SB
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