407 research outputs found
How financial markets process money information: A re-examination of evidence using band spectrum regression
Cataloged from PDF version of article.This article re-examines the response of financial markets to money supply announcements. It is argued that the previous research in the area may be suffering from an estimation bias. The potential for estimation bias stems from the questionable practice of assuming the same regression model for all frequency bands. A decomposition of the data into low-frequency and high-frequency components raises the possibility that both expected liquidity and expected inflation effects are in operation simultaneously though they affect different expectation horizons. The results also show that the distinct weight of these separate effects depends essentially on the credibility of the Fed in adhering to announced monetary targets and the state of inflationary fears
Spectral analysis of the relationship between energy consumption, employment, and business cycles
Through the use of cross-spectral techniques, we identify the dependence of U.S. industrial energy consumption on the industrial production index and total non-farm employment over business cycles. In particular, total energy consumption, mainly due to its industrial component, responds to changes in the production index. It is found that the industrial demand for energy is fairly sensitive to business cycles, while the household energy consumption and transportationsector energy consumption are not significantly affected by the expansion and contraction phases of the economy. In addition, there is a significant degree of correlation between the total non-farm employment and energy consumption over the business cycle frequencies. The evidence indicates a simultaneous response of employment and energy consumption to business cycle movements of the production index and suggests neutrality between energy and labor employment. © 1990
Podwyższony poziom greliny w stanie przedrzucawkowym: czy grelina jest przyjacielem czy wrogiem?
Objectives: To investigate maternal serum ghrelin levels in pregnancies complicated by preeclampsia and to explore the relationship between ghrelin level and disease severity.
Materials and methods: This case-control study included 40 healthy pregnant women, 42 women with mild preeclampsia, and 40 women with severe preeclampsia. The groups were matched in terms of maternal and gestational age and body mass index. Serum ghrelin levels were measured via enzyme immunoassay.
Results: Serum ghrelin levels were significantly higher in women with mild and severe preeclampsia than in healthy controls (p < 0.001). Although serum ghrelin levels were somewhat higher in the severe compared to the mild preeclampsia group, the difference was not statistically significant (p > 0.05). In the control group, no significant correlation was observed between ghrelin level and any other parameter, but in the preeclampsia group, serum ghrelin levels were negatively correlated with uterine artery Doppler index values and both systolic and diastolic blood pressure (all p-values < 0.05). Multivariate stepwise linear regression analysis revealed that systolic blood pressure (β = 0.493, p = 0.023) was independently associated with serum ghrelin level.
Conclusion: Elevated blood ghrelin levels were correlated with disease severity in pregnancies complicated by preeclampsia.Cel pracy: Ocena poziomu greliny w surowicy kobiet w ciąży powikłanej stanem przedrzucawkowym i określenie związku między poziomem greliny a ciężkością choroby.
Materiał i metoda: Do badania włączono 40 zdrowych kobiet w ciąży, 42 z łagodnym stanem przedrzucawkowym i 40 z ciężkim stanem przedrzucawkowym. Grupy były dobrane pod względem wieku ciążowego, wieku matek i wskaźnika masy ciała. Poziom greliny w surowicy był mierzony metodą immunoenzymatyczną.
Wyniki: Poziom greliny w surowicy był istotnie wyższy u kobiet z łagodnym i ciężkim stanem przedrzucawkowym niż w grupie kontrolnej (p < 0,001). Chociaż poziom greliny w surowicy był wyższy w grupie z ciężkim stanem przedrzucawkowym niż w grupie z łagodnym stanem przedrzucawkowym, to ta różnica nie była istotna statystycznie (p > 0,05). W grupie kontrolnej nie obserwowano żadnych istotnych związków pomiędzy poziomem greliny a jakimkolwiek innym parametrem, ale w grupie ze stanem przedrzucawkowym poziom greliny w surowicy był ujemnie skorelowany z indeksami przepływów Dopplera w tętnicy macicznej oraz ciśnieniem krwi skurczowym i rozkurczowym (all p-values < 0,05). Wieloczynnikowa analiza regresji liniowej wykazała, że skurczowe ciśnienie krwi było niezależnym czynnikiem związanym z poziomem greliny w surowicy (β = 0,493, p = 0,023).
Wnioski: Podwyższony poziom greliny we krwi był związany z ciężkością choroby w ciążach powikłanych stanem przedrzucawkowym
Evaluation of rate law approximations in bottom-up kinetic models of metabolism.
BackgroundThe mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws with reduced numbers of parameters. Whether such simplified models can reproduce dynamic characteristics of the full system is an important question.ResultsIn this work, we compared the local transient response properties of dynamic models constructed using rate laws with varying levels of approximation. These approximate rate laws were: 1) a Michaelis-Menten rate law with measured enzyme parameters, 2) a Michaelis-Menten rate law with approximated parameters, using the convenience kinetics convention, 3) a thermodynamic rate law resulting from a metabolite saturation assumption, and 4) a pure chemical reaction mass action rate law that removes the role of the enzyme from the reaction kinetics. We utilized in vivo data for the human red blood cell to compare the effect of rate law choices against the backdrop of physiological flux and concentration differences. We found that the Michaelis-Menten rate law with measured enzyme parameters yields an excellent approximation of the full system dynamics, while other assumptions cause greater discrepancies in system dynamic behavior. However, iteratively replacing mechanistic rate laws with approximations resulted in a model that retains a high correlation with the true model behavior. Investigating this consistency, we determined that the order of magnitude differences among fluxes and concentrations in the network were greatly influential on the network dynamics. We further identified reaction features such as thermodynamic reversibility, high substrate concentration, and lack of allosteric regulation, which make certain reactions more suitable for rate law approximations.ConclusionsOverall, our work generally supports the use of approximate rate laws when building large scale kinetic models, due to the key role that physiologically meaningful flux and concentration ranges play in determining network dynamics. However, we also showed that detailed mechanistic models show a clear benefit in prediction accuracy when data is available. The work here should help to provide guidance to future kinetic modeling efforts on the choice of rate law and parameterization approaches
Molecular Interactions that Enable Movement of the Lyme Disease Agent from the Tick Gut into the Hemolymph
Borrelia burgdorferi, the causative agent of Lyme disease, is transmitted to humans by bite of Ixodes scapularis ticks. The mechanisms by which the bacterium is transmitted from vector to host are poorly understood. In this study, we show that the F(ab)2 fragments of BBE31, a B.burgdorferi outer-surface lipoprotein, interfere with the migration of the spirochete from tick gut into the hemolymph during tick feeding. The decreased hemolymph infection results in lower salivary glands infection, and consequently attenuates mouse infection by tick-transmitted B. burgdorferi. Using a yeast surface display approach, a tick gut protein named TRE31 was identified to interact with BBE31. Silencing tre31 also decreased the B. burgdorferi burden in the tick hemolymph. Delineating the specific spirochete and arthropod ligands required for B. burgdorferi movement in the tick may lead to new strategies to interrupt the life cycle of the Lyme disease agent
Monocular Expressive Body Regression through Body-Driven Attention
To understand how people look, interact, or perform tasks, we need to quickly
and accurately capture their 3D body, face, and hands together from an RGB
image. Most existing methods focus only on parts of the body. A few recent
approaches reconstruct full expressive 3D humans from images using 3D body
models that include the face and hands. These methods are optimization-based
and thus slow, prone to local optima, and require 2D keypoints as input. We
address these limitations by introducing ExPose (EXpressive POse and Shape
rEgression), which directly regresses the body, face, and hands, in SMPL-X
format, from an RGB image. This is a hard problem due to the high
dimensionality of the body and the lack of expressive training data.
Additionally, hands and faces are much smaller than the body, occupying very
few image pixels. This makes hand and face estimation hard when body images are
downscaled for neural networks. We make three main contributions. First, we
account for the lack of training data by curating a dataset of SMPL-X fits on
in-the-wild images. Second, we observe that body estimation localizes the face
and hands reasonably well. We introduce body-driven attention for face and hand
regions in the original image to extract higher-resolution crops that are fed
to dedicated refinement modules. Third, these modules exploit part-specific
knowledge from existing face- and hand-only datasets. ExPose estimates
expressive 3D humans more accurately than existing optimization methods at a
small fraction of the computational cost. Our data, model and code are
available for research at https://expose.is.tue.mpg.de .Comment: Accepted in ECCV'20. Project page: http://expose.is.tue.mpg.d
The antibacterial properties of Malaysian tualang honey against wound and enteric microorganisms in comparison to manuka honey
<p>Abstract</p> <p>Background</p> <p>Antibiotic resistance of bacteria is on the rise, thus the discovery of alternative therapeutic agents is urgently needed. Honey possesses therapeutic potential, including wound healing properties and antimicrobial activity. Although the antimicrobial activity of honey has been effectively established against an extensive spectrum of microorganisms, it differs depending on the type of honey. To date, no extensive studies of the antibacterial properties of tualang (<it>Koompassia excelsa</it>) honey on wound and enteric microorganisms have been conducted. The objectives of this study were to conduct such studies and to compare the antibacterial activity of tualang honey with that of manuka honey.</p> <p>Methods</p> <p>Using a broth dilution method, the antibacterial activity of tualang honey against 13 wound and enteric microorganisms was determined; manuka honey was used as the control. Different concentrations of honey [6.25-25% (w/v)] were tested against each type of microorganism. Briefly, two-fold dilutions of honey solutions were tested to determine the minimum inhibitory concentration (MIC) against each type of microorganism, followed by more assays within a narrower dilution range to obtain more precise MIC values. MICs were determined by both visual inspection and spectrophotometric assay at 620 nm. Minimum bactericidal concentration (MBC) also was determined by culturing on blood agar plates.</p> <p>Results</p> <p>By visual inspection, the MICs of tualang honey ranged from 8.75% to 25% compared to manuka honey (8.75-20%). Spectrophotometric readings of at least 95% inhibition yielded MIC values ranging between 10% and 25% for both types of honey. The lowest MBC for tualang honey was 20%, whereas that for manuka honey was 11.25% for the microorganisms tested. The lowest MIC value (8.75%) for both types of honey was against <it>Stenotrophomonas maltophilia</it>. Tualang honey had a lower MIC (11.25%) against <it>Acinetobacter baumannii </it>compared to manuka honey (12.5%).</p> <p>Conclusion</p> <p>Tualang honey exhibited variable activities against different microorganisms, but they were within the same range as those for manuka honey. This result suggests that tualang honey could potentially be used as an alternative therapeutic agent against certain microorganisms, particularly <it>A. baumannii </it>and <it>S. maltophilia</it>.</p
Impact of antimicrobial drug restrictions on doctors' behaviors
Background/aim: Broad-spectrum antibiotics have become available for use only with the approval of infectious disease specialists (IDSs) since 2003 in Turkey. This study aimed to analyze the tendencies of doctors who are not disease specialists (non-IDSs) towards the restriction of antibiotics.Materials and methods: A questionnaire form was prepared, which included a total of 22 questions about the impact of antibiotic restriction (AR) policy, the role of IDSs in the restriction, and the perception of this change in antibiotic consumption. The questionnaire was completed by each participating physician.Results: A total of 1906 specialists from 20 cities in Turkey participated in the study. Of those who participated, 1271 (67.5%) had 5 years of occupational experience in their branch expressed that they followed the antibiotic guidelines more strictly than the JSs (P < 0.05) and 755 of physicians (88%) and 720 of surgeons (84.6%) thought that the AR policy was necessary and useful (P < 0.05).Conclusion: This study indicated that the AR policy was supported by most of the specialists. Physicians supported this restriction policy more so than surgeons did
Clinical significance of serum and urinary HER2/neu protein levels in primary non-muscle invasive bladder cancer
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