‘Testosterone Boosting’ Supplements Composition and Claims Are not Supported by the Academic Literature

Chase G. Clemesha,Hatim Thaker,Mary K. Samplaski 대한남성과학회 2020 The World Journal of Men's Health Vol.38 No.1

Purpose: Men take testosterone (T) boosting supplements to naturally improve T levels. We evaluated the composition and advertised claims of “T boosting” supplements, and supporting published evidence. Materials and Methods: Fifty “T booster” supplements were evaluated for active ingredients and product claims, discovered via Google search. PubMed was reviewed for any literature supporting the claims, followed by review of Recommended Daily Allowance (RDA) and upper tolerable intake level (UL) for each component. Results: Ninety percent of supplements claimed to “boost T”, 50% “improve libido”, and 48% “feel stronger”. One-hundred nine unique components were found, with a mean number of 8.3 per product. On PubMed, 24.8% of supplements had data showing an increase in T with supplementation, 10.1% had data showing a decrease in T, and 18.3% had data showing no change in T. No data were found on 61.5% of supplements on their effect on T. Supplements contained a median 1,291% of the RDA for vitamin B12, 807.6% for vitamin B6, 272% of zinc, 200% of vitamin B5, and 187.5% of vitamin B3. Thirteen products exceeded the US Food and Drug Administration UL of ingredients (zinc, vitamin B3, and magnesium). Conclusions: Ninety percent of “T booster” supplements claimed to boost T. However, only 24.8% of these had data to support these claims. A total of 10.1% contained components with data suggesting a negative effect on T. Many had supra-therapeutic doses of vitamins and minerals, occasionally over the UL. Patients should be informed that “T booster” supplements may not have ingredients to support their claims.

A semi-active acceleration-based control for seismically excited civil structures including control input impulses

Chase, J. Geoffrey,Barroso, Luciana R.,Hunt, Stephen Techno-Press 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.3

Structural acceleration regulation is a means of managing structural response energy and enhancing the performance of civil structures undergoing large seismic events. A quadratic output regulator that minimizes a measure including the total structural acceleration energy is developed and tested on a realistic non-linear, semi-active structural control case study. Suites of large scaled earthquakes are used to statistically quantify the impact of this type of control in terms of changes in the statistical distribution of controlled structural response. This approach includes the impulses due to control inputs and is shown to be more effective than a typical displacement focused control approach, by providing equivalent or better performance in terms of displacement and hysteretic energy reductions, while also significantly reducing peak story accelerations and the associated damage and occupant injury. For earthquake engineers faced with the dilemma of balancing displacement and acceleration demands this control approach can significantly reduce that concern, reducing structural damage and improving occupant safety.

간장 과학자

CHASE PETERSON-WITHORN 중앙일보에스 2023 Forbes Korea = 포브스 코리아 Vol.2023 No.11

Elucidating the Mechanism of Reversible Oxiranations via Magnetization Transfer Spectroscopy

Chase, Daniel T.,Moerdyk, Jonathan P.,Bielawski, Christopher W. American Chemical Society 2012 ORGANIC LETTERS Vol.14 No.21

<P>The reversible [2 + 1] cycloadditions between an <I>N</I>,<I>N</I>′-diamidocarbene (DAC) and eight aldehydes were examined using NMR spectroscopy. Variable temperature magnetization transfer experiments revealed higher exchange rates and lower activation barriers when electron-deficient aldehydes were employed. Likewise, competitive equilibrium studies indicated a thermodynamic preference for electron-deficient aryl and sterically unhindered alkyl aldehydes compared to more electron-rich or bulkier substrates. Collectively, these and other data collected were consistent with the oxiranation process proceeding in an asynchronous manner.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2012/orlef7.2012.14.issue-21/ol302596r/production/images/medium/ol-2012-02596r_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol302596r'>ACS Electronic Supporting Info</A></P>

PART Ⅰ. CULTURE AND DEVELOPMENT IN A NEW ERA AND IN A TRANSFORMING WORLD ; United States Culture and World Culture

Christopher Chase Dunn 경남대학교 극동문제연구소 1994 CULTURE & DEVELOPMENT Vol.- No.-

The Effect of WTO Membership on Service Sector Trade Liberalization

Englund Chase 인하대학교 정석물류통상연구원 2022 JOURNAL OF INTERNATIONAL LOGISTICS AND TRADE Vol.20 No.1

A large portion of labor and trade in most countries is devoted to the service sector, and thus service sector impacts are crucial to a full understanding of the effects of WTO membership. The effect of WTO membership on trade volume has been subject to debate in the past, but critically, these studies have failed to examine service sector trade specifically. Conventional wisdom would seem to suggest that WTO membership should have boosted services trade, particularly after the implementation of the General Agreement on Trade in Services (GATS) in 1995. However, the relationship has yet to be rigorously tested. Here, I use data comprising 178 countries across a span ranging from 1995 until 2015 to examine the impact that WTO membership, and specifically WTO accession, has had on service sector trade levels relative to goods trade levels after the adoption of GATS. Statistical tests yield weak evidence for any significant relationship between WTO membership and service sector trade, with some possible exceptions for states that underwent many rounds of negotiations. This exception is explored further through a comparison of the WTO accessions of China and Vietnam. However, even in these extreme cases, it is difficult to find clear evidence of service sector liberalization. Overall, the findings imply that, in almost all cases, WTO rules and accessions have underemphasized service sector trade in favor of agricultural and goods trade, generating lopsided impacts to trade efficiency.

Entertainment Content Across Cultures and with Multicultural Communities

Mackie Chase 한국엔터테인먼트산업학회 2009 한국엔터테인먼트산업학회 학술대회 논문집 Vol.3 No.1

Streamflow, stomata, and soil pits: Sources of inference for complex models with fast, robust uncertainty quantification

Dwelle, M. Chase,Kim, Jongho,Sargsyan, Khachik,Ivanov, Valeriy Y. C.M.L. Publications 2019 ADVANCES IN WATER RESOURCES Vol. No.

<P><B>Abstract</B></P> <P>The scale and complexity of environmental and earth systems introduce an array of uncertainties that need to be systematically addressed. In numerical modeling, the ever-increasing complexity of representation of these systems confounds our ability to resolve relevant uncertainties. Specifically, the numerical representation of the governing processes involve many inputs and parameters that have been traditionally treated as deterministic. Considering them as uncertain introduces a large computational burden, stemming from the requirement of a prohibitive number of model simulations. Furthermore, within hydrology, most catchments are sparsely monitored, and there are limited, heterogeneous types of data available to confirm the model’s behavior. Here we present a blueprint of a general approach to uncertainty quantification for complex hydrologic models, taking advantage of recent methodological developments. We rely on polynomial chaos machinery to construct accurate surrogates that can be efficiently sampled for the ecohydrologic model tRIBS-VEGGIE to mimic its behavior with respect to a selected set of quantities of interest. The use of the Bayesian compressive sensing technique allows for fewer evaluations of the computationally expensive tRIBS-VEGGIE. The approach enables inference of model parameters using a set of observed hydrologic quantities including stream discharge, water table depth, evapotranspiration, and soil moisture from the Asu experimental catchment near Manaus, Brazil. The results demonstrate the flexibility of the framework for hydrologic inference in watersheds with sparse, irregular observations of varying accuracy. Significant computational savings imply that problems of greater computational complexity and dimension can be addressed using accurate, computationally cheap surrogates for complex hydrologic models. This will ultimately yield probabilistic representation of model behavior, robust parameter inference, and sensitivity analysis without the need for greater investment in computational resources.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A general approach to uncertainty quantification with a complex, process-rich model. </LI> <LI> Construction of efficient surrogate models with Bayesian compressive sensing. </LI> <LI> Robust parametric inference using heterogeneous sources of process-scale data. </LI> <LI> Simultaneous characterization of sensitivity of hydrologic outputs to uncertain variables. </LI> </UL> </P>

A semi-active acceleration-based control for seismically excited civil structures including control input impulses

J. Geoffrey Chase,L. R. Barroso,Stephen Hung 국제구조공학회 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.18 No.3

Accuracy and robustness of hysteresis loop analysis in the identification and monitoring of plastic stiffness for highly nonlinear pinching structures

J. Geoffrey Chase,Hamish Tomlinson,Geoffrey W. Rodgers,Chao Xu,Virginie Avot,Cong Zhou 국제구조공학회 2023 Smart Structures and Systems, An International Jou Vol.31 No.2

Structural health monitoring (SHM) covers a range of damage detection strategies for buildings. In real-time, SHM provides a basis for rapid decision making to optimise the speed and economic efficiency of post-event response. Previous work introduced an SHM method based on identifying structural nonlinear hysteretic parameters and their evolution from structural force-deformation hysteresis loops in real-time. This research extends and generalises this method to investigate the impact of a wide range of flag-shaped or pinching shape nonlinear hysteretic response and its impact on the SHM accuracy. A particular focus is plastic stiffness (<i>k<sub>p</sup></>), where accurate identification of this parameter enables accurate identification of net and total plastic deformation and plastic energy dissipated, all of which are directly related to damage and infrequently assessed in SHM. A sensitivity study using a realistic seismic case study with known ground truth values investigates the impact of hysteresis loop shape, as well as added noise, on SHM accuracy using a suite of 20 ground motions from the PEER database. Monte Carlo analysis over 22,000 simulations with different hysteresis loops and added noise resulted in absolute percentage identification error (median, (IQR)) in <i>k<sub>p</sup></> of 1.88% (0.79, 4.94)%. Errors were larger where five events (Earthquakes #1, 6, 9, 14) have very large errors over 100% for resulted <i>k<sub>p</sup></> as an almost entirely linear response yielded only negligible plastic response, increasing identification error. The sensitivity analysis shows accuracy is reduces to within 3% when plastic drift is induced. This method shows clear potential to provide accurate, real-time metrics of non-linear stiffness and deformation to assist rapid damage assessment and decision making, utilising algorithms significantly simpler than previous non-linear structural model-based parameter identification SHM methods.