bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk of lymphatic or haematopoietic cancer mortality with occupational exposure to animals or the public
Authors: Svec M A , Ward M H , Dosemeci M , Checkoway H , De Roos A J 
Published: September 2005

Background:Occupational exposure to animals or the public could result in exposure to infectious agents, which may play a role in the aetiology of lymphohaematopoietic (LH) cancers.Aims:To conduct a population based, case-control study of death certificate data from 1984 to 1998 in 24 US states in order to evaluate the risk of mortality from LH neoplasms associated with occupational exposure to animals or the public.Methods:Cases were selected as those with an underlying cause of death of non-Hodgkin’s lymphoma (NHL, n = 72 589), Hodgkin’s disease (HD, n = 5479), multiple myeloma (n = 35 857), or leukaemia (n = 68 598); 912 615 controls were randomly selected from all remaining deaths, frequency matched on age, sex, race, and geographic region.Results:Occupational exposure to animals was associated with modest increased risks of mortality from all four LH cancers; these associations varied by region. Occupational exposure to the public was associated with only negligible increased risk with LH cancer outcomes. Occupations involving animal exposure were predominantly agricultural, and the risks associated with employment in the livestock industry exceeded the corresponding risks associated with the crop industry for all outcomes except HD.Conclusions:Increased risks of NHL, HD, multiple myeloma, and leukaemia were associated with occupations that involved animal exposure. Regional differences in risk imply that the risks may be associated with exposure to specific livestock or farming practices. However, these associations may be confounded by other farming related exposures, such as pesticides. Because the use of death certificates to classify occupation may result in misclassification during aetiologically relevant time periods, these hypotheses should be further explored in studies with detailed information on lifetime occupation.
Analysis of an Idealized, Three-Dimensional Diabatic Rossby Vortex: A Coherent Structure of the Moist Baroclinic Atmosphere
Authors: Moore Richard W. , Montgomery Michael T. 
Published: September 2005

Abstract
The fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) is used to conduct a number of idealized numerical simulations to confirm recent findings of an alternate growth mechanism in a moist baroclinic environment to that of traditional baroclinic instability. In this alternate growth scenario, disturbance growth depends on the presence of sufficient environmental moisture and baroclinicity. The resulting coherent structure, termed a diabatic Rossby vortex (DRV), grows as a result of an approximate phase locking and mutual amplification of two diabatically generated potential vorticity (PV) anomalies: a low-level positive (cyclonic) PV anomaly and a midtropospheric negative (anticyclonic) PV anomaly.
The three-dimensional structure of a DRV is found to be qualitatively very similar to that seen in previous two-dimensional model simulations. The most apparent structural discrepancy from the two-dimensional model is the increased strength of the midtropospheric negative PV anomaly in the three-dimensional simulations.
A sensitivity study is undertaken to better understand the dependence of the DRV dynamics on some of the more pertinent environmental and perturbation vortex parameters, and to quantify the effect of each parameter. The resulting intensity of a DRV is most sensitive to the magnitude of environmental baroclinicity and moisture content, while the vertical profile of moisture is the most dominant factor in determining the characteristic depth of the DRV. It is also found that the “size” and “amplitude” of a precursor perturbation vortex are important factors in determining the track and intensity of the ensuing DRV.
The Dynamics of Phase Locking
Authors: Krishnamurti T. N. , Chakraborty D. R. 
Published: September 2005

AbstractMany low-frequency phenomena such as the Madden–Julian oscillation (MJO) or the El Niño–Southern Oscillation (ENSO) exhibit rapid growth where they appear to be undergoing a phase locking with other time scales such as the annual cycle. The purpose of this paper is to illustrate an example of phase locking of two different time scales. In this instance it is shown that during such epochs of phase locking a large increase in nonlinear energy exchange occurs from one time scale to the other. This paper utilizes the ECMWF Re-Analysis (ERA-40) datasets for the year 2001 to examine this problem. This study is a sequel to a recent modeling study where the maintenance of the MJO time scale was examined from scale interactions, especially with synoptic-scale waves with ∼2–7 day periods. It was shown that a pair of waves on the synoptic time scale can satisfy certain selection rules and undergo triad interactions (kinetic energy to kinetic energy exchanges) and transfer energy. This present study illustrates the fact that during epochs of phase locking such nonlinear interactions can become very large, thus portraying the importance of phase locking. These explosive exchanges are shown from two perspectives: an approach based on kinetic energy exchanges in the frequency domain and another that invokes the boundary layer dynamics in the frequency domain.
Zonal and Vertical Structure of the Madden–Julian Oscillation
Authors: Kiladis George N. , Straub Katherine H. , Haertel Patrick T. 
Published: September 2005

AbstractA statistical study of the three-dimensional structure of the Madden–Julian oscillation (MJO) is carried out by projecting dynamical fields from reanalysis and radiosonde data onto space–time filtered outgoing longwave radiation (OLR) data. MJO convection is generally preceded by low-level convergence and upward motion in the lower troposphere, while subsidence, cooling, and drying prevail aloft. This leads to moistening of the boundary layer and the development of shallow convection, followed by a gradual and then more rapid lofting of moisture into the middle troposphere at the onset of deep convection. After the passage of the heaviest rainfall, a westerly wind burst region is accompanied by stratiform precipitation, where lower tropospheric subsidence and drying coincide with continuing upper tropospheric upward motion. The evolution of the heating field leads to a temperature structure that favors the growth of the MJO. The analysis also reveals distinct differences in the vertical structure of the MJO as it evolves, presumably reflecting changes in its vertical heating profile, phase speed, or the basic-state circulation that the MJO propagates through.The dynamical structure and the evolution of cloud morphology within the MJO compares favorably in many respects with other propagating convectively coupled equatorial waves. One implication is that the larger convective envelopes within the Tropics tend to be composed of more shallow convection along their leading edges, a combination of deep convection and stratiform rainfall in their centers, and then a preponderance of stratiform rainfall along their trailing edges, regardless of scale or propagation direction. While this may ultimately be the factor that governs the dynamical similarities across the various wave types, it raises questions about how the smaller-scale, higher-frequency disturbances making up the MJO conspire to produce its heating and dynamical structures. This suggests that the observed cloud morphology is dictated by fundamental interactions with the large-scale circulation.
Reply
Authors: Jochum Markus , Malanotte-Rizzoli Paola 
Published: September 2005

Abstract
A previous study on the generation of equatorial subsurface countercurrents is revisited to clarify some details of the assumptions that are needed to derive the momentum budget. The opportunity is also used to put the study into the context of other previous studies that use quasigeostrophic theory to generalize the transformed Eulerian mean equations.
Anomalies of Meridional Overturning: Mechanisms in the North Atlantic
Authors: Köhl Armin 
Published: September 2005

Abstract
Optimal observations are used to investigate the overturning streamfunction in the North Atlantic at 30°N and 900-m depth. Those observations are designed to impact the meridional overturning circulation (MOC) in numerical models maximally when assimilated and therefore establish the most efficient observation network for studying changes in the MOC. They are also ideally suited for studying the related physical mechanisms in a general circulation model. Optimal observations are evaluated here in the framework of a global 1° model over a 10-yr period. Hydrographic observations useful to monitor the MOC are primarily located along the western boundary north of 30°N and along the eastern boundary south of 30°N. Additional locations are in the Labrador, Irminger, and Iberian Seas. On time scales of less than a year, variations in MOC are mainly wind driven and are made up through changes in Ekman transport and coastal up- and downwelling. Only a small fraction is buoyancy driven and constitutes a slow response, acting on time scales of a few years, to primarily wintertime anomalies in the Labrador and Irminger Seas. Those anomalies are communicated southward along the west coast by internal Kelvin waves at the depth level of Labrador Sea Water. They primarily set the conditions at the northern edge of the MOC anomaly. The southern edge is mainly altered through Rossby waves of the advective type, which originate from temperature and salinity anomalies in the Canary Basin. Those anomalies are amplified on their way westward in the baroclinic unstable region of the subtropical gyre. The exact meridional location of the maximum MOC response is therefore set by the ratio of the strength of these two signals.
Euploidy in somatic cells from R6/2 transgenic Huntington's disease mice
Authors: Petersén Åsa , Stewénius Ylva , Björkqvist Maria , Gisselsson David 
Published: September 2005

Abstract

Background
Huntington's disease (HD) is a hereditary neurodegenerative disorder caused by a CAG repeat expansion in the HD gene. The huntingtin protein expressed from HD has an unknown function but is suggested to interact with proteins involved in the cell division machinery. The R6/2 transgenic mouse is the most widely used model to study HD. In R6/2 fibroblast cultures, a reduced mitotic index and high frequencies of multiple centrosomes and aneuploid cells have recently been reported. Aneuploidy is normally a feature closely connected to neoplastic disease. To further explore this unexpected aspect of HD, we studied cultures derived from 6- and 12-week-old R6/2 fibroblasts, skeletal muscle cells, and liver cells.

Results
Cytogenetic analyses revealed a high frequency of polyploid cells in cultures from both R6/2 and wild-type mice with the greatest proportions of polyploid cells in cultures derived from skeletal muscle cells of both genotypes. The presence of polyploid cells in skeletal muscle in vivo was confirmed by fluorescence in situ hybridisation with centromeric probes. Enlarged and supernumerary centrosomes were found in cultures from both R6/2 and wild-type mice. However, no aneuploid cells could be found in any of the tissues.

Conclusion
We conclude that polyploid cells are found in fibroblast and skeletal muscle cultures derived from both R6/2 and wild-type littermate mice and that aneuploidy is unlikely to be a hallmark of HD.
Exposure to the field of renal transplantation during undergraduate medical education in the UK
Authors: Edwards Anusha G , Newman Alex , Morgan Justin D 
Published: September 2005

Abstract

Background
There is a lack of surgeons in the field of renal transplantation, with a predicted shortage of over 20 consultants by the year 2005. Early positive exposure to the field, commencing at undergraduate level, has been identified as being vital to improving rates of recruitment. This study was performed to assess the exposure of undergraduates to the field of renal transplantation during medical education in the UK.

Methods
In October 2004 a questionnaire was sent to the clinical deans of all UK medical schools regarding undergraduate exposure to renal transplantation.

Results
Twenty-five replies were received, giving a response rate of 96%. All but one school had a centre for renal transplantation in their region. Three schools (12%) gave no formal lecture or tutorial on the subject during the entire course. Of the remainder, between one to four formal sessions were provided, ranging from 15 minutes to 3 hours duration.
Six medical schools (24%) provided no compulsory clinical exposure to renal transplantation, with a further five (20%) saying that students may receive exposure by chance. The average length of attachment was three weeks. Twenty-one medical schools (84%) provided between 1–10% of students a choice to study renal transplantation, as part of electives and special study modules.

Conclusion
This study reveals a variation between, and within, medical schools in the levels of formal teaching. If the trends in recruitment to renal transplantation are to be reversed, we have an obligation to improve upon the medical education that students currently receive.
Stroke volume and cardiac output in juvenile elephant seals during forced dives
Authors: Thornton Sheila J. , Hochachka Peter W. , Crocker Daniel E. , Costa Daniel P. , LeBoeuf Burney J. , Spielman Daniel M. , Pelc Norbert J. 
Published: September 2005

SUMMARYThe aim of this study was to examine the effect of forced diving on cardiac dynamics in a diving mammal by evaluating cardiac output and heart rate. We used MR Imaging and phase contrast flow analysis to obtain accurate flow measurements from the base of the aorta. Heart rate (fh)and cardiac output (Q̇) were measured before, during and after dives in four restrained juvenile northern elephant seals, Mirounga angustirostris, and stroke volume(Vs) was calculated(Vs=Q̇/fh). Mean Q̇ during diving (4011±387 ml min-1) and resting (6530±1018 ml min-1) was not significantly different (paired t-test; P&lt;0.055). Diving was accompanied by a 20% increase in Vs over the pre-dive level. Pre-dive, post-dive or diving fh was not significantly correlated with Vs during any state. Diving Vs correlated negatively with the bradycardic ratio(diving fh to pre-dive fh). In this study, the degree of bradycardia during diving was less than in previous pinniped studies, suggesting that the reduction in vagal input may contribute to the observed increase in Vs.
Prior classical olfactory conditioning improves odour-cued flight orientation of honey bees in a wind tunnel
Authors: Chaffiol Antoine , Laloi David , Pham-Delègue Minh-Hà 
Published: September 2005

SUMMARYOdours are key cues used by the honey bee in various situations. They play an important role in sexual attraction, social behaviour and location of profitable food sources. Here, we were interested in the role of odours in orientation at short distance, for instance the approach flight to a floral patch or in close proximity to the hive entrance. Using a newly designed wind tunnel, we investigated the orientation behaviour of the bee towards two different odours: a social odour and a floral component, linalool. We then tested the effect of prior olfactory conditioning (conditioning of the proboscis extension reflex) on subsequent flight orientation. We showed that both stimuli induced orientated behaviour (orientated flights, circling around the odour source) in up to 70% of the worker bees, social odour being slightly more attractive than the linalool. We found thereafter that orientation performance towards the floral compound can be significantly enhanced by prior classical olfactory learning. This type of information transfer, from a Pavlovian associative context to an orientation task, might allow future foragers to acquire, within the hive, relevant information about the odours and food they will encounter during their later foraging bouts.
Feeding kinematics ofKogiaandTursiops(Odontoceti:Cetacea): characterization of suction and ram feeding
Authors: Bloodworth Brian , Marshall Christopher D. 
Published: September 2005

SUMMARYThe feeding kinematics of dwarf and pygmy sperm whales (Kogia simaand K. breviceps) and bottlenose dolphins Tursiops truncatuswere characterized and compared incorporating the Ram-Suction Index (RSI). Mean RSI data support a suction feeding strategy for Kogia(-0.67±0.29; mean ± s.d.) and a ram feeding strategy for Tursiops (0.94±0.11; mean ± s.d.). Tursiops displayed two ram-based feeding behaviours: open gape approach, where gape was at least 50% of maximum in the first video field, and closed gape approach, where gape increased near food items. Four feeding phases were identified in both odontocetes: preparatory, jaw opening, gular depression and jaw closing. The mean Kogia feeding cycle duration(470±139 ms) was significantly shorter (P&lt;0.003) than all Tursiops groups (pooled: 863±337 ms; open gape approach:1211±207 ms; closed gape approach: 662±207 ms). Kogiamean maximum gape angle (39.8±18.9°), mean maximum opening and closing gape angle velocities (293±261 deg. s-1 and 223±121 deg. s-1, respectively) were significantly greater(P&lt;0.005) than pooled Tursiops mean maximum gape angle(24.8±6.6°), mean maximum opening and closing gape angle velocities(84±56 deg. s-1 and 120±54 deg. s-1,respectively). Negative Kogia RSI values were correlated with increasing maximum gular depression and retraction, wide gape angle, and rapid opening gape angle velocity. Kinematic data support functional hypotheses that odontocetes generate suction by rapid depression of the hyoid and tongue.
Integration of hydrodynamic and odorant inputs by local interneurons of the crayfish deutocerebrum
Authors: Mellon DeForest 
Published: September 2005

SUMMARYIntracellular electrodes were used to record from local interneurons in the olfactory lobes of the midbrain in the crayfish Procambarus clarkii.Cells that resembled previously studied central targets of olfactory receptor neurons on the lateral antennular flagellum were specifically examined for their responses to hydrodynamic stimuli. Initiation of water movement past the antennular flagellum, confined within an olfactometer, evoked a triphasic excitatory-inhibitory-excitatory postsynaptic potential lasting up to 2 s that generated spikes on depolarizing phases of the response sequence. Odorant pulses seamlessly imbedded in the water pulse past the antennule evoked purely excitatory, dose-dependent postsynaptic responses and associated spike trains. The latency of the initial phase of the response to water was approximately half as long as the latency of the response to odorant, suggesting that different afferent pathways are involved in responses to hydrodynamic and odorant stimuli, respectively. In some olfactory lobe interneurons that resembled previously described cells classified as Type I, conjoint stimulation of fluid onset and odorant evoked responses that were twice the amplitude of the summed response to either hydrodynamic or odorant stimulation alone, suggesting that the olfactory responses were potentiated by hydrodynamic input. Individuals of at least one other class of first-order interneuron that responded to both hydrodynamic and odorant stimulation were occasionally recorded from. These results indicate that multimodal integration of chemical and mechanical information occurs at the level of first-order sensory interneurons in the crayfish brain.
Enhancement of Excitatory Synaptic Integration by GABAergic Inhibition in the Subthalamic Nucleus
Authors: Baufreton Jérôme , Atherton Jeremy F. , Surmeier D. James , Bevan Mark D. 
Published: September 2005

The activity patterns of subthalamic nucleus (STN) neurons, which are intimately related to normal movement and abnormal movement in Parkinson's disease (PD), are sculpted by feedback GABAergic inhibition from the reciprocally connected globus pallidus (GP). To understand the principles underlying the integration of GABAergic inputs, we used gramicidin-based patch-clamp recording of STN neurons in rat brain slices. Voltage-dependent Na+(Nav) channels actively truncated synthetic IPSPs and were required for autonomous activity. In contrast, hyperpolarization-activated cyclic nucleotide-gated and class 3 voltage-dependent Ca2+channels contributed minimally to the integration of single or low-frequency trains of IPSPs and autonomous activity. Interestingly, IPSPs modified action potentials (APs) in a manner that suggested IPSPs enhanced postsynaptic Navchannel availability. This possibility was confirmed in acutely isolated STN neurons using current-clamp recordings containing IPSPs as voltage-clamp waveforms. Tetrodotoxin-sensitive subthreshold and spike-associated Na+currents declined during autonomous spiking but were indeed transiently boosted after IPSPs. A functional consequence of inhibition-dependent augmentation of postsynaptic excitability was that EPSP–AP coupling was dramatically improved when IPSPs preceded EPSPs.Because STN neuronal activity exhibits coherence with cortical β-oscillations in PD, we tested how rhythmic sequences of cortical EPSPs were integrated in the absence and presence of feedback inhibition. STN neuronal activity was consistently entrained by EPSPs only in the presence of feedback inhibition. These observations suggest that feedback inhibition from the GP is critical for the emergence of coherent β-oscillations between the cortex and STN in PD.
20-Oxo-5β-Pregnan-3α-yl Sulfate Is a Use-Dependent NMDA Receptor Inhibitor
Authors: Petrovic Milos , Sedlacek Miloslav , Horak Martin , Chodounska Hana , Vyklický Ladislav 
Published: September 2005

NMDA receptors are ligand-gated ion channels permeable to calcium and play a critical role in excitatory synaptic transmission, synaptic plasticity, and excitotoxicity. They are heteromeric complexes of NR1 combined with NR2A-D and/or NR3A-B subunits that are activated by glutamate and glycine and whose activity is modulated by allosteric modulators. In this study, patch-clamp recordings from human embryonic kidney 293 cells expressing NR1/NR2 receptors were used to study the molecular mechanism of the endogenous neurosteroid 20-oxo-5β-pregnan-3α-yl sulfate (3α5βS) action at NMDA receptors. 3α5βS was a twofold more potent inhibitor of responses mediated by NR1/NR2C-D receptors than those mediated by NR1/NR2A-B receptors. The structure of the extracellular loop between the third and fourth transmembrane domains of the NR2 subunit was found to be critical for the neurosteroid inhibitory effect. The degree of 3α5βS-induced inhibition of responses to glutamate was voltage independent, with recovery lasting several seconds. In contrast, application of 3α5βS in the absence of agonist had no effect on the subsequent response to glutamate made in the absence of the neurosteroid. A kinetic model was developed to explain the use-dependent action of 3α5βS at NMDA receptors. In accordance with the model, 3α5βS was a less potent inhibitor of NMDA receptor-mediated EPSCs and responses induced by a short application of 1 mmglutamate than of those induced by a long application of glutamate.These results suggest that 3α5βS is a use-dependent but voltage-independent inhibitor of NMDA receptors, with more potent action at tonically than at phasically activated receptors. This may be important in the treatment of excitotoxicity-induced neurodegeneration.