Search results for "sampling"

Maternal serum ghrelin levels in early IVF pregnancies: lack of prognostic value for viable pregnancy and altered post-prandial responses

2008

Background Ghrelin is a pleiotropic hormone, involved in the control of growth and metabolism, whose circulating levels fluctuate in relation to food intake and body mass index. Ghrelin has been detected in the decidualized endometrium, as well as in human and rat placenta. Methods A total of 106 patients undergoing IVF procedures were prospectively recruited. On Days 16 and 23 after oocyte retrieval, the patients were subjected to blood sampling after overnight fasting, for determination of serum ghrelin, hCGbeta and progesterone levels. In addition, ghrelin levels were assayed in these groups, 2 h after ingestion of a fixed-calorie meal. Results The subjects were divided according to whet…

Expression of aquaporins early in human pregnancy

2011

Abstract Background Aquaporins (AQPs) constitute a family of channel proteins implicated in transmembrane water transport. Thirteen different AQPs (AQP0–12) have been described but their precise biologic function still remains unclear. AQPs 1, 3, 4, 8, and 9 expression has been described in human chorion, amnion and placenta; however, AQP4 is the only that has been identified in the first trimester of human pregnancy. Objective To assess multiplicity of AQPs expression from 10th to 14th week gestation. Population and methods Chorionic villi samples (CVS) collected in pregnant women for prenatal diagnosis were analysed by real time-PCR to assess cDNA expression of AQPs 1, 2, 3, 4, 5, 6, 7, 8…

Circulating miR-200–family micro-RNAs have altered plasma levels in patients with endometriosis and vary with blood collection time

2015

Objective To determine whether circulating micro-RNA (miR) 200a, miR-200b, and miR-141 have altered levels in patients with endometriosis compared with control individuals. Design Experimental laboratory study. Setting University. Patient(s) Patients with endometriosis (n = 61), laparoscopically confirmed endometriosis-free women (n = 35), and self-reported healthy women (n = 30) were included in the study. Intervention(s) None. Main Outcome Measure(s) Plasma miRNA levels in endometriosis patients and control subjects. Result(s) We found that the levels of studied miRNAs varied with blood collection time, being lower in the morning than in the evening. When blood collection time was taken i…

Thompson Sampling Guided Stochastic Searching on the Line for Non-stationary Adversarial Learning

2015

This paper reports the first known solution to the N-Door puzzle when the environment is both non-stationary and deceptive (adversarial learning). The Multi-Armed-Bandit (MAB) problem is the iconic representation of the exploration versus exploitation dilemma. In brief, a gambler repeatedly selects and play, one out of N possible slot machines or arms and either receives a reward or a penalty. The objective of the gambler is then to locate the most rewarding arm to play, while in the process maximize his winnings. In this paper we investigate a challenging variant of the MAB problem, namely the non-stationary N-Door puzzle. Here, instead of directly observing the reward, the gambler is only…

Hearing as a Predictor of Falls and Postural Balance in Older Female Twins

2009

BACKGROUND: The purpose of the present study was to examine, first, whether hearing acuity predicts falls and whether the potential association is explained by postural balance and, second, to examine whether shared genetic or environmental effects underlie these associations. METHODS: Hearing was measured using a clinical audiometer as a part of the Finnish Twin Study on Aging in 103 monozygotic and 114 dizygotic female twin pairs aged 63-76 years. Postural balance was indicated as a center of pressure (COP) movement in semitandem stance, and participants filled in a fall-calendar daily for an average of 345 days after the baseline. RESULTS: Mean hearing acuity (better ear hearing threshol…

Sampling and analysis of pesticides in ambient air.

2008

Developments in the sampling and determination of pesticides in ambient air have been discussed and data on the occurrence of pesticides in atmosphere have been presented. Developments in active sampling methods were reviewed and the different materials used for trapping pesticides from gas and particulate phases were discussed. Likewise, the use and developments of passive air samplers were reviewed. This article pays special attention to the analysis of pesticides trapped from ambient air, and recapitulate the procedures for extraction, clean-up and determination of these substances. Improvements in sampling procedures, analytical methods and monitoring activities are necessary to advance…

Environmental applications (air)

2020

Abstract The use of solid sorbent-based devices for the monitoring of contaminants in the air is a widespread trend due to its versatility, physicochemical stability, and high enrichment factor. Active and passive sampling strategies have been developed for air monitoring using different materials, such as carbon-based organic polymers and inorganic sorbents. It has been updated in the literature regarding the most recent applications of the use of solid sorbent-based samplers for the monitoring of air in different sites such as rural, urban, industrialized, and indoor areas, including workplace environments for the evaluation of occupational exposure risks.

Passive Air Sampling

2016

Error estimation and reduction with cross correlations

2010

Besides the well-known effect of autocorrelations in time series of Monte Carlo simulation data resulting from the underlying Markov process, using the same data pool for computing various estimates entails additional cross correlations. This effect, if not properly taken into account, leads to systematically wrong error estimates for combined quantities. Using a straightforward recipe of data analysis employing the jackknife or similar resampling techniques, such problems can be avoided. In addition, a covariance analysis allows for the formulation of optimal estimators with often significantly reduced variance as compared to more conventional averages.

Noninvasive sampling of phenylalanine by reverse iontophoresis.

1999

While iontophoresis is typically associated with drug delivery across the skin, the symmetry of the technique permits its application to the essentially noninvasive withdrawal of biologically important analytes from the subcutaneous space to the body's surface. The identification of other substances which can be monitored by this procedure, and to its optimization and development as a more general clinical chemistry tool, is a long-term objective. In this paper, we describe a preliminary in vitro investigation into the feasibility of extracting and analyzing the amino acid, phenylalanine, with the ultimate aim to develop a diagnostic test for phenylketonuria, a potentially fatal metabolic d…