206 research outputs found
Ants diversity and composition between two wildlife corridor of Bukit Belata forest reserve and Bukit Tunggal Forest Reserve
Understanding the diversity and composition of two forest corridors will provide invaluable information on the suitability of the proposed wildlife corridor. Ants were used as bioindicator to determine to health status Bukit Belata and Bukit Tunggal Forest Reserves. Sampling were done using pitfall traps and leaf litter sifting along a 500m line transect. A total of 35 species of ants belonging to 15 genera and 4 subfamilies were collected. Bukit Belata FR yielded higher number of species compared to Bukit Tunggal FR. However, the species composition in Bukit Tunggal comprised mainly forest specialist species instead of generalist species in Bukit Belata
Review of food toxicological issues associated in rubber products
Over the centuries, rubber latex gained its popularity in machinery application due to its unique thermal properties, high elasticity and excellent impact resistance. It is widely accepted in food industry as rubber has good resistance to chemicals, including acids, alkalis and salts. For instance, rubber components comprise of couplings, shields, dust covers, gaskets and seals exist as group or standalone component in food manufacturing equipments or machinery. Even though most of the rubber based products in food industry fulfil the requirements of Food and Drug Administration (FDA), however, the presence of trace amount of chemicals upon the preceding processing of rubber might accidentally contaminate to the food products. The contamination that happened might caused changes in food quality in term of taste, smell or even visual appearance. Therefore, this paper aims to review some of the manufacturing process of natural rubber products and to understand the possibility of extractable and leachable contaminated food products. An overview of potential toxicological problems will be discussed and the finding will be summarized in this paper
QRS duration and cardiovascular mortality in Asian patients with heart failure and preserved and reduced ejection fraction
Restriction fragment mass polymorphism (RFMP) analysis based on MALDI-TOF mass spectrometry for detecting antiretroviral resistance in HIV-1 infected patients
AbstractViral genotype assessment is important for effective clinical management of HIV-1 infected patients, especially when access and/or adherence to antiretroviral treatment is reduced. In this study, we describe development of a matrix-assisted laser desorption/ionization-time of flight mass spectrometry-based viral genotyping assay, termed restriction fragment mass polymorphism (RFMP). This assay is suitable for sensitive, specific and high-throughput detection of multiple drug-resistant HIV-1 variants. One hundred serum samples from 60 HIV-1-infected patients previously exposed to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) were analysed for the presence of drug-resistant viruses using the RFMP and direct sequencing assays. Probit analysis predicted a detection limit of 223.02 copies/mL for the RFMP assay and 1268.11 copies/mL for the direct sequencing assays using HIV-1 RNA Positive Quality Control Series. The concordance rates between the RFMP and direct sequencing assays for the examined codons were 97% (K65R), 97% (T69Ins/D), 97% (L74VI), 97% (K103N), 96% (V106AM), 97% (Q151M), 97% (Y181C), 97% (M184VI) and 94% (T215YF) in the reverse transcriptase coding region, and 100% (D30N), 100% (M46I), 100% (G48V), 100% (I50V), 100% (I54LS), 99% (V82A), 99% (I84V) and 100% (L90M) in the protease coding region. Defined mixtures were consistently and accurately identified by RFMP at 5% relative concentration of mutant to wild-type virus while at 20% or greater by direct sequencing. The RFMP assay based on mass spectrometry proved to be sensitive, accurate and reliable for monitoring the emergence and early detection of HIV-1 genotypic variants that lead to drug resistance
VERITAS: the Very Energetic Radiation Imaging Telescope Array System
The Very Energetic Radiation Imaging Telescope Array System (VERITAS)
represents an important step forward in the study of extreme astrophysical
processes in the universe. It combines the power of the atmospheric Cherenkov
imaging technique using a large optical reflector with the power of
stereoscopic observatories using arrays of separated telescopes looking at the
same shower. The seven identical telescopes in VERITAS, each of aperture 10 m,
will be deployed in a filled hexagonal pattern of side 80 m; each telescope
will have a camera consisting of 499 pixels with a field of view of 3.5 deg
VERITAS will substantially increase the catalog of very high energy (E >
100GeV) gamma-ray sources and greatly improve measurements of established
sources.Comment: 44 pages, 16 figure
Density and well width dependences of the effective mass of twodimensional holes in (100) GaAs quantum wells measured by cyclotron resonance at microwave frequencies
Cyclotron resonance at microwave frequencies is used to measure the band mass
(m_b) of the two-dimensional holes (2DH's) in carbon-doped (100)
GaAs/AlxGa1-xAs heterostructures. The measured m_b shows strong dependences on
both the 2DH density(p) and the GaAs quantum well width (W). For a fixed W, in
the density range (0.4x10^11 to 1.1x10^11 cm^-2) studied here, m_b increases
with p, consistent with previous studies of the 2DHs on the (311)A surface. For
a fixed p = 1.1x10^11 cm^-2, mb increases from 0.22 m_e at W = 10 nm to 0.50
m_e at W = 30 nm, and saturates around 0.51 m_e for W > 30 nm.Comment: to appear in Solid State Communication
YAP and TAZ protect against white adipocyte cell death during obesity
The expansion of the white adipose tissue (WAT) in obesity goes along with increased mechanical, metabolic and inflammatory stress. How adipocytes resist this stress is still poorly understood. Both in human and mouse adipocytes, the transcriptional co-activators YAP/TAZ and YAP/TAZ target genes become activated during obesity. When fed a high-fat diet (HFD), mice lacking YAP/TAZ in white adipocytes develop severe lipodystrophy with adipocyte cell death. The pro-apoptotic factor BIM, which is downregulated in adipocytes of obese mice and humans, is strongly upregulated in YAP/TAZ-deficient adipocytes under HFD, and suppression of BIM expression reduces adipocyte apoptosis. In differentiated adipocytes, TNFα and IL-1β promote YAP/TAZ nuclear translocation via activation of RhoA-mediated actomyosin contractility and increase YAP/TAZ-mediated transcriptional regulation by activation of c-Jun N-terminal kinase (JNK) and AP-1. Our data indicate that the YAP/TAZ signaling pathway may be a target to control adipocyte cell death and compensatory adipogenesis during obesity
The First VERITAS Telescope
The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic
Radiation Imaging Telescope Array System) has been in operation since February
2005. We present here a technical description of the instrument and a summary
of its performance. The calibration methods are described, along with the
results of Monte Carlo simulations of the telescope and comparisons between
real and simulated data. The analysis of TeV -ray observations of the
Crab Nebula, including the reconstructed energy spectrum, is shown to give
results consistent with earlier measurements. The telescope is operating as
expected and has met or exceeded all design specifications.Comment: Accepted by Astroparticle Physic
Gamma-ray Observations Under Bright Moonlight with VERITAS
Imaging atmospheric Cherenkov telescopes (IACTs) are equipped with sensitive
photomultiplier tube (PMT) cameras. Exposure to high levels of background
illumination degrades the efficiency of and potentially destroys these
photo-detectors over time, so IACTs cannot be operated in the same
configuration in the presence of bright moonlight as under dark skies. Since
September 2012, observations have been carried out with the VERITAS IACTs under
bright moonlight (defined as about three times the night-sky-background (NSB)
of a dark extragalactic field, typically occurring when Moon illumination >
35%) in two observing modes, firstly by reducing the voltage applied to the
PMTs and, secondly, with the addition of ultra-violet (UV) bandpass filters to
the cameras. This has allowed observations at up to about 30 times previous NSB
levels (around 80% Moon illumination), resulting in 30% more observing time
between the two modes over the course of a year. These additional observations
have already allowed for the detection of a flare from the 1ES 1727+502 and for
an observing program targeting a measurement of the cosmic-ray positron
fraction. We provide details of these new observing modes and their performance
relative to the standard VERITAS observations
Diagnostic Accuracy of the Electrocardiogram for Heart Failure With Reduced or Preserved Ejection Fraction
Current heart failure (HF) guidelines recommend electrocardiography (ECG) as an essential initial investigation in a patient's workup. 1 However, these recommendations were based on studies primarily including patients with HF with reduced ejection fraction (HFrEF). 1 , 2 , 3 Guidelines do not distinguish HFrEF from HF with preserved and mid-range ejection fraction (HFpEF and HFmrEF) in their ECG recommendations. We hypothesized that a normal ECG does not exclude HFpEF and has a considerably lower sensitivity for diagnosing HFpEF than HFrEF
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