1,283 research outputs found
Diagnosis of invasive fungal infections in immunocompromised children
AbstractEarly recognition and rapid initiation of effective treatment is a prerequisite for successful management of children with invasive fungal infections. The increasing diversity of fungal pathogens in high-risk patients, the differences in the antifungal spectra of available agents and the increasing rates of resistance call for identification of the infecting isolate at the species level and for information on drug resistance, in order to provide state-of-the-art patient care. Microscopy and culture of appropriate specimens remain the reference standard for mycological diagnosis, despite difficulties in obtaining appropriate and/or sufficient specimens, long durations of culture and false-negative results. Modern imaging studies and detection of circulating fungal cell wall components and DNA in blood and other body fluids or in affected tissues may improve the laboratory diagnosis of invasive mycoses
Reduction of vehicle power assisted steering noise
Introduction: To achieve low levels of noise and vibration in the interior of a vehicle, the noise levels from
major sources such as the engine and transmission have been greatly reduced in recent years.
Unfortunately, this has meant that the noise from ancillary components has become relatively
more prominent. One such component is the power assisted steering (PAS) system, the noise
from which is a problem on nearly all vehicles. This paper reports an investigation into the
moaning noise produced when the steering wheel is turned at idle, commonly known as PAS
moan. The major factors involved in PAS moan are: the transmission of structure-borne and
air-borne noise through the vehicle; the transmission of pressure ripples in the hydraulic
circuit of the PAS system; and the generation of flow ripples at the PAS pump. In section 3
the results of a study into the reduction of PAS moan is reported. Section 3.1 outlines the
experimental set-up and measurement technique. Section 3.2 reports on the effect on vehicle
interior noise of the installation of the of the PAS system. Section 3.3 reports on the influence
of tuning hoses in the PAS hydraulic circuit and section 3.4 gives an assessment of the
reduction in interior noise due to a modification of the power steering pump. The findings
outlined in this paper are part of more detailed study into power steering noise reported in
reference [1]
The effect of monensin on milk production, milk urea nitrogen and body condition score of grazing dairy cows
Twenty Holstein-Friesian cows, two to four months postpartum, were randomly assigned to two groups. The control group received no monensin, whereas the treatment group received 300 mg monensin per cow per day. Cows grazed kikuyu pasture and received maize-based concentrates (2% of body weight) in two equal feeds after the morning and afternoon milkings. Monensin was supplemented with the concentrates for six weeks. Monensin supplementation reduced the numbers (x 105/cm3 ) of small protozoa (9.1 vs. 13.0) and large protozoa (0.37 vs. 1.09) in the rumen. No significant difference was recorded between control and treatment groups for average milk yield (21.6 ± 0.7 vs. 22.1 ± 0.7 kg/day), milk protein (2.91 ± 0.05 vs. 2.84 ± 0.04 %) or milk fat (2.75 ± 0.13 vs. 2.69 ± 0.12 %). The combined morning and afternoon milk urea nitrogen concentrations of the monensin supplemented cows (19.9 ± 1.37 mg/dl) were lower than those of the control group (24.1 ± 1.43 mg/dl). The average daily gain of the treatment group (471.4 ± 87.5 g/day) was higher than that of the control group (193.9 ± 52.8 g/day). No significant difference was observed between the average condition score of the control (1.4 ± 0.1) and treatment (1.7 ± 0.1) groups after six weeks. Although monensin supplementation reduced milk urea nitrogen concentrations, these were still in the critical zone (> 18 mg/dl) which could negatively affect fertility. Monensin can play an important part in ensuring that cows are in a stable or improving condition (i.e. gaining weight) at service time, this being an important prerequisite for improved reproductive efficiency.
(South African Journal of Animal Science, 2001, 31(1): 49-55
An application of multimedia in teaching mechanical vibrations
An application of multimedia in teaching mechanical vibration
Development of a Master of Science programme in Automotive Systems Engineering
Development of a Master of Science programme in Automotive Systems Engineerin
Chaos Synchronization and Spontaneous Symmetry Breaking in Symmetrically Delay Coupled Semiconductor Lasers
PACS: 05.45.Xt, 42.55.Px, 42.65.SfWe present experimental and numerical investigations of the dynamics of two device-identical, optically coupled semiconductor lasers exhibiting a delay in the coupling. Our results give evidence for subnanosecond coupling-induced synchronized chaotic dynamics in conjunction with a spontaneous symmetry-breaking: we find a well-defined time lag between the dynamics of the two lasers, and an asymmetric physical role of the subsystems. We demonstrate that the leading laser synchronizes its lagging counterpart, whereas the synchronized lagging laser drives the coupling-induced instabilities.Peer reviewe
Clinical Pharmacokinetics, Pharmacodynamics, Safety and Efficacy of Liposomal Amphotericin B
Item does not contain fulltextSince its introduction in the 1990s, liposomal amphotericin B (LAmB) continues to be an important agent for the treatment of invasive fungal diseases caused by a wide variety of yeasts and molds. This liposomal formulation was developed to improve the tolerability of intravenous amphotericin B, while optimizing its clinical efficacy. Since then, numerous clinical studies have been conducted, collecting a comprehensive body of evidence on its efficacy, safety, and tolerability in the preclinical and clinical setting. Nevertheless, insights into the pharmacokinetics and pharmacodynamics of LAmB continue to evolve and can be utilized to develop strategies that optimize efficacy while maintaining the compound's safety. In this article, we review the clinical pharmacokinetics, pharmacodynamics, safety, and efficacy of LAmB in a wide variety of patient populations and in different indications, and provide an assessment of areas with a need for further clinical research
Remotely Keyed Cryptographics: Secure Remote Display Access Using (Mostly) Untrusted Hardware
Software that covertly monitors user actions, also known as spyware, has become a first-level security threat due to its ubiquity and the difficulty of detecting and removing it. Such software may be inadvertently installed by a user that is casually browsing the web, or may be purposely installed by an attacker or even the owner of a system. This is particularly problematic in the case of utility computing, early manifestations of which are Internet cafes and thin-client computing. Traditional trusted computing approaches offer a partial solution to this by significantly increasing the size of the trusted computing base (TCB) to include the operating system and other software. We examine the problem of protecting a user accessing specific services in such an environment. We focus on secure video broadcasts and remote desktop access when using any convenient, and often untrusted, terminal as two example applications. We posit that, at least for such applications, the TCB can be confined to a suitably modified graphics processing unit (GPU). Specifically, to prevent spyware on untrusted clients from accessing the user's data, we restrict the boundary of trust to the client's GPU by moving image decryption into GPUs. This allows us to leverage existing capabilities as opposed to designing a new component from scratch. We discuss the applicability of GPU-based decryption in the two scenarios. We identify limitations due to current GPU capabilities and propose straightforward modifications to GPUs that will allow the realization of our approach
Chemical telemetry of OH observed to measure interstellar magnetic fields
We present models for the chemistry in gas moving towards the ionization
front of an HII region. When it is far from the ionization front, the gas is
highly depleted of elements more massive than helium. However, as it approaches
the ionization front, ices are destroyed and species formed on the grain
surfaces are injected into the gas phase. Photodissociation removes gas phase
molecular species as the gas flows towards the ionization front. We identify
models for which the OH column densities are comparable to those measured in
observations undertaken to study the magnetic fields in star forming regions
and give results for the column densities of other species that should be
abundant if the observed OH arises through a combination of the liberation of
H2O from surfaces and photodissociation. They include CH3OH, H2CO, and H2S.
Observations of these other species may help establish the nature of the OH
spatial distribution in the clouds, which is important for the interpretation
of the magnetic field results.Comment: 11 pages, 2 figures, accepted by Astrophysics and Space Scienc
Hormonal modulation of breast cancer gene expression: implications for intrinsic subtyping in premenopausal women
Clinics are increasingly adopting gene-expression profiling to diagnose breast cancer subtype, providing an intrinsic, molecular portrait of the tumor. For example, the PAM50- based Prosigna test quantifies expression of 50 key genes to classify breast cancer subtype, and this method of classification has been demonstrated to be superior over traditional immunohistochemical methods that detect proteins, to predict risk of disease recurrence. However, these tests were largely developed and validated using breast cancer samples from postmenopausal women. Thus, the accuracy of such tests has not been explored in the context of the hormonal fluctuations in estrogen and progesterone that occur during the menstrual cycle in premenopausal women. Concordance between traditional methods of subtyping and the new tests in premenopausal women is likely to depend on the stage of the menstrual cycle at which the tissue sample is taken and the relative effect of hormones on expression of genes versus proteins. The lack of knowledge around the effect of fluctuating estrogen and progesterone on gene expression in breast cancer patients raises serious concerns for intrinsic subtyping in premenopausal women, which comprise about 25% of breast cancer diagnoses. Further research on the impact of the menstrual cycle on intrinsic breast cancer profiling is required if premenopausal women are to benefit from the new technology of intrinsic subtyping.Sarah M. Bernhardt, Pallave Dasari, David Walsh, Amanda R. Townsend, Timothy J. Price, and Wendy V. Ingma
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