bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phenotypic Switching in
Candida lusitaniae
on Copper Sulfate Indicator Agar: Association with Amphotericin B Resistance and Filamentation
Authors: Miller Nancy S. , Dick James D. , Merz William G. 
Published: April 2006

ABSTRACT

Candida lusitaniae
is an opportunistic yeast pathogen that has the ability to develop resistance to amphotericin B (AmB). The mechanism(s) for this resistance is not well understood, although there are data supporting mutations in sterol pathways and other data supporting phenotypic switching (PS). The goal of this study was to determine whether
C. lusitaniae
has a PS system and to characterize any phenotypes, including any changes in AmB MICs. When 10
4
CFU of an AmB-resistant (MIC of 16 to 32 μg/ml) clinical strain was plated on yeast-peptone-dextrose (YPD) agar with 1 mM CuSO
4
, three colony colors were observed: light brown (LB) ≫ dark brown (DB) > white (W), similar to the result for
Candida glabrata
. Switching did occur with high AmB resistance (MIC of 256 μg/ml) being associated with W, whereas LB and DB colonies had MICs of 2 to 8 μg/ml and 2 to 16 μg/ml, respectively. Filamentation (pseudohyphae) was associated with DB colonies. All phenotypes occurred spontaneously with greater frequency (∼10
−2
to 10
−4
) than spontaneous mutations, and all phenotypes were reversible, fulfilling the two PS criteria. High AmB MICs were always associated with W colonies but not with all W colonies. Detection of PS on YPD-CuSO
4
is also similar to that in
Candida glabrata
, and we hypothesize that this is due to similarities in metallothionein gene expression. Phenotypic switching represents a key strategy in
C. lusitaniae
that confers a selective advantage during environmental challenges, including the ability to switch to AmB resistance.
Seroprevalence and Molecular Epidemiology of Human T-Cell Leukemia Virus Type 1 (HTLV-1) and HTLV-2 in Blood Donors from Dakar, Senegal
Authors: Diop Saliou , Calattini Sara , Abah-Dakou Julienne , Thiam Doudou , Diakhaté Lamine , Gessain Antoine 
Published: April 2006

ABSTRACT
In 2002, human T-cell leukemia virus type 1 (HTLV-1) and HTLV-2 seroprevalence was 0.16% (8/4,900) in blood donors from Dakar, Senegal. Most of the positive donors originated from the country’s southern region. Seven donors were infected by HTLV-1 (of cosmopolitan subtype), and one was infected by HTLV-2. These data highlight the problem of transfusion safety in this area where HTLV-1-associated lymphoproliferative and neurological diseases are endemic.
Microevolution of the Direct Repeat Locus of
Mycobacterium tuberculosis
in a Strain Prevalent in San Francisco
Authors: Aga Roxanne S. , Fair Elizabeth , Abernethy Neil F. , DeRiemer Kathryn , Paz E. Antonio , Kawamura L. Masae , Small Peter M. , Kato-Maeda Midori 
Published: April 2006

ABSTRACT

We describe a microevolutionary event of a prevalent strain of
Mycobacterium tuberculosis
that caused two outbreaks in San Francisco. During the second outbreak, a direct variable repeat was lost. We discuss the mechanisms of this change and the implications of analyzing multiple genetic loci in this context.
Discovery of the Neutralizing Epitope Common to Influenza B Virus Victoria Group Isolates in Japan
Authors: Nakagawa Naoko , Suzuoki Jun , Kubota Ritsuko , Kobatake Shinzo , Okuno Yoshinobu 
Published: April 2006

ABSTRACT
Monoclonal antibody 9B2 possesses hemagglutination inhibition activity against all the 2002/2003 influenza B virus Victoria group isolates in Kobe, Japan, as well as representative strains isolated between 1987 and 1997. The 9B2 epitope localizes three-dimensionally in the vicinity of antigenic site A of the hemagglutinin molecule, and amino acid substitutions in this region affected the binding of 9B2.
Dismembering the ethical physician
Authors: Genuis S J 
Published: April 2006

Abstract
Physicians may experience ethical distress when they are caught in difficult clinical situations that demand ethical decision making, particularly when their preferred action may contravene the expectations of patients and established authorities. When principled and competent doctors succumb to patient wishes or establishment guidelines and participate in actions they perceive to be ethically inappropriate, or agree to refrain from interventions they believe to be in the best interests of patients, individual professional integrity may be diminished, and ethical reliability is potentially compromised. In a climate of ever-proliferating ethical quandaries, it is essential for the medical community, health institutions, and governing bodies to pursue a judicious tension between the indispensable regulation of physicians necessary to maintain professional standards and preserve public safety, and the support for “freedom of conscience” that principled physicians require to practise medicine in keeping with their personal ethical orientation.
Diffusion weighted magnetic resonance imaging for acute stroke: practical and popular
Authors: Tan P L , King D , Durkin C J , Meagher T M , Briley D 
Published: April 2006

Abstract

Aim
To evaluate the feasibility and impact of diffusion weighted magnetic resonance imaging (DW MRI) as the first line neuroimaging of stroke at a district general hospital.

Methods
Prospective audit of all in-patients admitted with clinically suspected acute stroke and referred for imaging over a consecutive 17 week period. The data collected included scan type, time from cerebral event to imaging request, and time from formal radiological request to neuroimaging. Clinicians' (general physicians, neurologists, and radiologists) perceptions were assessed by a questionnaire.

Results
148 patients had neuroimaging for clinically suspected stroke during this period. Eighty one per cent of patients (120 of 148) had DW MRI as first line. Ninety two per cent of these patients had DW MRI within 24 hours of the formal radiological request. Twenty eight patients did not undergo DW MRI because lack of MRI safety, clinical state, unavailability because of maintenance service or lack of trained staff. Clinicians found the introduction of the DW MRI based service a significant improvement on computed tomography, especially for equivocal cases.

Conclusion
DW based MRI service is both feasible and sustainable in the setting of a district general hospital and most clinicians feel that this is a significant improvement to stroke services.
Effects of ageing on smell and taste
Authors: Boyce J M , Shone G R 
Published: April 2006

Abstract
Disorders of taste and smell commonly present diagnostic dilemmas to the medical profession. This may be secondary to the lack of knowledge and understanding of these conditions. There seems to be a low level of interest in the disorders, when compared with disruption of the other senses such as sight and hearing. Nevertheless, impairment of these senses are common and may be life threatening, especially when they involve the elderly patient. The aetiology of the conditions is widespread, and extend beyond the content of this article. This article will relate only to how the ageing process may contribute to sensory dysfunction. It will focus on how the ageing process changes the normal anatomy and physiology of the senses, how this effects the person's quality of life, and the current management of these conditions.
Aetiology, diagnosis, and management of hypopituitarism in adult life
Authors: Prabhakar V K B , Shalet S M 
Published: April 2006

Abstract
Hypopituitarism is a complex medical condition associated with increased morbidity and mortality, requires complicated treatment regimens, and necessitates lifelong follow up by the endocrinologist. The causes, clinical features, and the management of hypopituitarism including endocrine replacement therapy are considered in this review article.
Practical experience of using directly observed procedures, mini clinical evaluation examinations, and peer observation in pre-registration house officer (FY1) trainees
Authors: Morris A , Hewitt J , Roberts C M 
Published: April 2006

Abstract
This paper describes an eight month experience with three of the four main assessment tools that will be used to validate the successful completion of the FY1 placement. The practical issues around the implementation of these new tools is of great concern to all involved in the management of postgraduate training and it is hoped that this paper will contribute some of the practical elements so far unavailable from Department of Health sources.
Assessment of internet use and effects among healthcare professionals: a cross sectional survey
Authors: Podichetty V K , Booher J , Whitfield M , Biscup R S 
Published: April 2006

Abstract

Purpose
Several studies have explored the scientific platforms on patient use of the internet for health information. In contrast physicians' perspective on evolving internet environment is lacking. The purpose of this study is to assess and correlate the extent of internet use among healthcare professionals and examine its effects on clinical practice.

Methods
Cross sectional survey conducted in the USA using questionnaires distributed randomly to healthcare professionals attending distinct continuing medical education programmes between 2003 and 2004. Multiple choice and yes/no questions related to the trends of internet use and its effects on clinical practice were extracted and responses analysed. The main outcome measures are self reported rates of internet use, perceived effects, and the role of medical web sites in clinical practice.

Results
The overall response rate was 60%. A total of 277 survey respondents (97%) had internet access. Some 7% in private practice and 1% of group practice physicians did not have internet access. Most (71%) used the internet regularly for medical or professional updating and 62% (n = 178) felt the need for sharing web sites designed for healthcare professionals with patients. Some 27% of the physicians currently own established personal practice web sites. Sixty three per cent have recommended a web site to a patient for more information, matching the positive trust (&gt;70%) on the general quality of selected medical web sites.

Conclusion
This cross sectional survey shows that internet use and web based medical information is widely popular among physicians and patients. About 23%–31% of the healthcare professionals report &gt;80% interaction with web informed patients in their daily practice.
Prevalence of obesity in type 2 diabetes in secondary care: association with cardiovascular risk factors
Authors: Daousi C , Casson I F , Gill G V , MacFarlane I A , Wilding J P H , Pinkney J H 
Published: April 2006

Abstract

Aims
To determine the prevalence of overweight and obesity among patients with type 1 and type 2 diabetes mellitus attending a secondary care diabetes clinic in the United Kingdom, and to assess the impact of overweight and obesity on glycaemic control and cardiovascular risk factors in patients with type 2 diabetes.

Methods
3637 patients with diabetes were identified from the hospital electronic diabetes register, 916 with type 1 diabetes (mean (SD) age 40.4 (15.1) years, 496 male) and 2721 with type 2 diabetes (mean (SD) age 62.5 (11.8) years, 1436 male). Data on body mass index (BMI), glycaemic control, lipid profiles, and blood pressure were extracted.

Results
Of patients with type 1 diabetes, 55.3% were overweight (BMI ⩾25 kg/m2), 16.6% were obese (BMI ⩾30 kg/m2), and 0.4% had morbid obesity (BMI ⩾40 kg/m2). In contrast, 86% of patients with type 2 diabetes were overweight or obese, 52% were obese, and 8.1% had morbid obesity. Obese patients with type 2 diabetes were younger, had poorer glycaemic control, higher blood pressures, worse lipid profiles, and were more likely to be receiving antihypertensive and lipid lowering drugs compared with patients with BMI &lt;30 kg/m2.

Conclusions
Obesity is the rule among patients attending this hospital diabetes clinic, with 86% of those with type 2 diabetes overweight or obese. Obesity is associated with significantly worse cardiovascular risk factors in this patient group, suggesting that more active interventions to control weight gain would be appropriate.
Microphysical and Geometrical Controls on the Pattern of Orographic Precipitation
Authors: Roe Gerard H. , Baker Marcia B. 
Published: April 2006

Abstract
Patterns of orographic precipitation can vary significantly both in time and space, and such variations must ultimately be related to mountain geometry, cloud microphysics, and synoptic conditions. Here an extension of the classic upslope model is presented, which incorporates an explicit representation in the vertical dimension, represents the finite growth time of hydrometeors, their downwind advection by the prevailing wind, and also allows for evaporation. For a simple mountain geometry the authors derive an analytical solution for the precipitation rate, which can be understood in terms of four nondimensional parameters. The finite growth time and slanting hydrometeor trajectories give rise to some interesting possibilities: a precipitation rate that maximizes at intermediate values of the horizontal wind speed, localized precipitation efficiencies in excess of 100%, and a reverse rain shadow with more precipitation falling on the leeward flank than on the windward flank.
The Role of the North American Topography on the Maintenance of the Great Plains Summer Low-Level Jet*
Authors: Ting Mingfang , Wang Hailan 
Published: April 2006

Abstract
Summer precipitation over the central United States depends strongly on the strength of the Great Plains low-level jet (LLJ). The Geophysical Fluid Dynamics Laboratory’s new generation of the atmospheric general circulation model (GCM) and the linear and nonlinear stationary wave models are used in this study to examine the role of North American topography in maintaining the Great Plains summer mean LLJ and precipitation. Atmospheric GCM experiments were first performed with and without the North American topography and with prescribed climatological sea surface temperatures. Results show that the Great Plains LLJ disappears completely in the experiment when the North American topography is removed, while the summer seasonal mean LLJ is well simulated in the experiment with full earth topography. In the absence of the North American topography, the summer precipitation is significantly reduced over the central United States and increased along the Gulf States and northeast Mexico.
Linear and nonlinear stationary wave models are used to determine the physical mechanisms through which the North American topography maintains the Great Plains time mean LLJ. Possible mechanisms include the physical blocking of the topography and the induced flow over and around the mountains, the thermal effect due to the elevation of the topography, and the transient thermal and vorticity forcing due to the modification of transient eddy activities in the presence of the topography. The linear and nonlinear model results indicate that the dominant mechanism for maintaining the time mean Great Plains LLJ is through the nonlinear effect of the trade wind along the southern flank of the North Atlantic subtropical high encountering the east slope of the Sierra Oriental and causing the flow to turn northward. As the flow turns north along the east slope of the North American topography, it obtains anticyclonic shear vorticity and thus the LLJ. The effect of the thermal forcing is negligible, while the effect of transient forcing is only important in extending the jet farther northward and eastward. The results suggest that variations in the strength of the North Atlantic subtropical anticyclone and the associated trade wind over the Caribbean Sea and the Gulf of Mexico may be important for understanding the interannual variation of the Great Plains LLJ and U.S. precipitation.
Aerosol and Cloud Microphysical Characteristics of Rifts and Gradients in Maritime Stratocumulus Clouds
Authors: Sharon Tarah M. , Albrecht Bruce A. , Jonsson Haflidi H. , Minnis Patrick , Khaiyer Mandana M. , van Reken Timothy M. , Seinfeld John , Flagan Rick 
Published: April 2006

Abstract
A cloud rift is characterized as a large-scale, persistent area of broken, low-reflectivity stratocumulus clouds usually surrounded by a solid deck of stratocumulus. A rift observed off the coast of California was investigated using an instrumented aircraft to compare the aerosol, cloud microphysical, and thermodynamic properties in the rift with those of the surrounding solid stratocumulus deck. The microphysical characteristics in the solid stratocumulus deck differ substantially from those of a broken, cellular rift where cloud droplet concentrations are a factor of 2 lower than those in the solid cloud. Furthermore, cloud condensation nuclei (CCN) concentrations were found to be about 3 times greater in the solid-cloud area compared with those in the rift. Although drizzle was observed near cloud top in parts of the solid stratocumulus cloud, the largest drizzle rates were associated with the broken clouds within the rift area and with extremely large effective droplet sizes retrieved from satellite data. Minimal thermodynamic differences between the rift and solid cloud deck were observed. In addition to marked differences in particle concentrations, evidence of a mesoscale circulation near the solid cloud–rift boundary is presented. This mesoscale circulation may provide a mechanism for maintaining a rift, but further study is required to understand the initiation of a rift and the conditions that may cause it to fill. A review of results from previous studies indicates similar microphysical characteristics in rift features sampled serendipitously. These observations indicate that cloud rifts are depleted of aerosols through the cleansing associated with drizzle and are a manifestation of natural processes occurring in marine stratocumulus.
Diagnosing Monthly Mean Boundary Layer Properties from Reanalysis Data Using a Bulk Boundary Layer Model
Authors: Ahlgrimm Maike , Randall David A. 
Published: April 2006

Abstract
The mixed-layer approach to modeling the planetary boundary layer (PBL) is particularly well suited to inversion-topped PBLs, such as the stratocumulus-topped boundary layer found off the west coast of America in the subtropical Pacific Ocean at northern and southern latitudes. However, a strong temperature inversion near 850 hPa (the trade wind inversion) is not confined to the stratocumulus regimes, but has been observed over most parts of the subtropical–tropical Pacific Ocean. In this paper, the authors test the ability of a simple bulk boundary layer model (BBLM) to diagnose entrainment velocity, cumulus mass flux, and surface latent heat flux from monthly mean reanalysis data. The PBL depth is estimated from Geoscience Laser Altimeter System data. The model is based on the conservation equations for mass, total water mixing ratio, and moist static energy.
The BBLM diagnoses entrainment velocities between 1 and 8 mm s−1 in the stratocumulus and trade wind regions, with increasing rates toward the west. Large cumulus mass fluxes (1.3–2 cm s−1) mark the ITCZ and South Pacific convergence zone. Unreasonably large surface latent heat fluxes are diagnosed in regions where the vertical resolution of both model and input data are insufficient to represent the sharp gradients of moist conservable variables and winds across the PBL top. The results demonstrate that the potential exists to extract useful information about the large-scale structure of PBL physical processes by combining available observations with simple models.
Interaction of an Asymmetric Double Vortex and Trochoidal Motion of a Tropical Cyclone with the Concentric Eyewall Structure
Authors: Oda Masahito , Nakanishi Mikio , Naito Gen’ichi 
Published: April 2006

Abstract
Radar echo images demonstrate that mature tropical cyclones frequently have a concentric eyewall structure, which consists of the inner eyewall, echo-free moat, and outer eyewall regions. Near the inner and outer eyewalls, well-defined wind maxima are generally observed. This indicates that two large vertical vorticity regions exist just inside radii of the two wind maxima near the inner and outer eyewalls. Therefore, the concentric eyewall structure can be considered to be a double vortex composed of the inner vortex and the outer vortex ring. In this study, the contour dynamics model is used on the f plane to analyze the characteristics of flows with either a symmetric double vortex or an asymmetric one, and examined the relationship between the movement of the inner vortex in an asymmetric double vortex and a trochoidal motion of a tropical cyclone with an asymmetric concentric eyewall structure.
Results show that, depending on the degree of an interaction of a double vortex, the evolution of the inner vortex is classified into three patterns: the first is that the center of the inner vortex is stationary, which is seen only for the symmetric double vortex; the second is that the track of the center of the inner vortex draws a circle; and the third is that it draws a spiral. A numerical experiment based on an observed flow around Typhoon Herb was also performed. The time evolution of the double vortex is very similar to that of radar echo intensity of Typhoon Herb. Also the rotation period and amplitude of the inner vortex in the numerical experiment were comparable with those of the trochoidal motion in the observation. These suggest that, in tropical cyclones with the concentric eyewall structure, the interaction of an asymmetric double vortex can become a cause of trochoidal motion.
Multiple Regimes and Low-Frequency Oscillations in the Northern Hemisphere’s Zonal-Mean Flow
Authors: Kravtsov S. , Robertson A. W. , Ghil M. 
Published: April 2006

Abstract
This paper studies multiple regimes and low-frequency oscillations in the Northern Hemisphere zonal-mean zonal flow in winter, using 55 yr of daily observational data. The probability density function estimated in the phase space spanned by the two leading empirical orthogonal functions exhibits two distinct, statistically significant maxima. The two regimes associated with these maxima describe persistent zonal-flow states that are characterized by meridional displacements of the midlatitude jet, poleward and equatorward of its time-mean position. The geopotential height anomalies of either regime have a pronounced zonally symmetric component, but largest-amplitude anomalies are located over the Atlantic and Pacific Oceans. High-frequency synoptic transients participate in the maintenance of and transitions between these regimes.
Significant oscillatory components with periods of 147 and 72 days are identified by spectral analysis of the zonal-flow time series. These oscillations are described by singular spectrum analysis and the multitaper method. The 147-day oscillation involves zonal-flow anomalies that propagate poleward, while the 72-day oscillation only manifests northward propagation in the Atlantic sector. Both modes mainly describe changes in the midlatitude jet position and intensity. In the horizontal plane though, the two modes exhibit synchronous centers of action located over the Atlantic and Pacific Oceans. The two persistent flow regimes are associated with slow phases of either oscillation.