bluuebunny/crossref_metadata_2025 huggingface dataset:
Deviations from Hardy–Weinberg proportions for multiple alleles under viability selection
Authors: ALVAREZ GONZALO
Published: May 2008

Departures of genotype frequencies from Hardy–Weinberg proportions (HWP) for a single autosomal locus due to viability selection in a random mating population have been studied only for the two-allele case. In this article, the analysis of deviations from HWP due to constant viability selection is extended to multiple alleles. The deviations for an autosomal locus withkalleles are measured by means ofk fiifixation indices for homozygotes andk(k−1)/2fijfixation indices for heterozygotes, and expressions are obtained for these indices (FISstatistics) under the multiallele viability model. Furthermore, expressions forfiiandfijwhen the multiallele polymorphism is at stable equilibrium are also derived and it is demonstrated that the pattern of multiallele Hardy–Weinberg deviations at equilibrium is characterized by a global heterozygote excess and a deficiency of each of the homozygotes. This pattern may be useful for detecting whether a given multiallelic polymorphism is at stable equilibrium in the population due to viability selection. An analysis of Hardy–Weinberg deviations from published data for the three-allele polymorphism at the β-globin locus in human populations from West Africa is presented for illustration.
Understanding the population genetic structure of coastal species (Cakile maritima): seed dispersal and the role of sea currents in determining population structure
Authors: GANDOUR MHEMMED , HESSINI KAMEL , ABDELLY CHEDLY
Published: May 2008

The nature and extent of long-distance seed dispersal are currently poorly understood, largely due to the inherent difficulty in detecting such a phenomenon. Genetic methods provide one of the few general approaches that offer the potential to accurately address this issue. Phenotypic and allozymic approaches were applied to characterize inter-population seed dispersal of the sea rocket (Cakile maritima, Brassicaceae), a glabrous and succulent annual herb. Genetic variation was assessed on 360 individuals sampled from nine populations. Genetic diversity across populations was high, 37% of which was represented by Qst and 16% by Fst. When genetic distances were used to construct the UPGMA dendrogram, populations were clustered into three groups at the 90% similarity level. The pattern of clustering can be explained by examining the direction of sea currents around Tunisian coasts. We have shown in this study thatC. maritimaseeds can survive up to 4 months immersion in sea water and up to 1 year of floating in sea water; therefore, seed dispersal between populations is possible both in terms of seed survival and current patterns.
Validation of multi-channel auditory steady-state response in adults with sensorineural hearing loss
Authors: Lin Y-H , Chen P-R , Hsu C-J , Wu H-P
Published: May 2008

Objective:

For various medico-legal and financial reasons, some patients may clinically demonstrate an exaggerated hearing loss that varies in degree, nature and laterality. The purpose of this study was to evaluate whether multi-channel auditory steady-state response measurement can be used as an objective test of auditory thresholds in adults with sensorineural hearing loss.

Study design and setting:

This was a prospective, comparative, experimental research design study conducted in an academic medical centre. From January to June 2007, 142 subjects (284 ears) with varying degrees of sensorineural hearing loss were included. Four commonly used frequencies (500, 1000, 2000 and 4000 Hz) were evaluated. Both pure tone thresholds and multi-channel auditory steady-state response thresholds were obtained for each ear in all subjects. The correlation of auditory steady-state response thresholds and pure tone thresholds was assessed. The time taken for multi-channel auditory steady-state response testing was also recorded.

Results:

Results for multi-channel auditory steady-state response thresholds and pure tone thresholds were compared for each test frequency. A difference of less than 15 dB was found in 71 per cent of patients, while a difference of less than 20 dB was found in 83 per cent. Correlation between auditory steady-state response thresholds and pure tone thresholds, expressed as the correlation coefficient (r), was 0.89, 0.95, 0.96 and 0.97 at 500, 1000, 2000 and 4000 Hz, respectively. The strength of the relationship between auditory steady-state response thresholds and pure tone thresholds increased with increasing frequency and increasing degree of hearing loss. The recorded auditory steady-state response thresholds were used to calculate regression lines predicting pure tone threshold results. The mean estimated pure tone thresholds calculated from these regression lines were all within 10 dB of the actual recorded pure tone thresholds. The average multi-channel auditory steady-state response test duration was 42 minutes per patient.

Conclusion:

Measurement of multi-channel auditory steady-state response could be a powerful, convenient electro-physiological examination with which to objectively certify clinical hearing impairment in adults.
Transmastoid repair of superior semicircular canal dehiscence
Authors: Kirtane M V , Sharma A , Satwalekar D
Published: May 2008

Objective:

The aim of this study was to describe the successful operative management of a patient with superior semicircular canal dehiscence syndrome, using the transmastoid approach under local anaesthesia.

Methods:

The transmastoid approach was used to plug the superior semicircular canal.

Results:

Post-operatively, the patient experienced significant improvement in his symptoms of sound- and pressure-induced dysequilibrium, autophony and imbalance.

Conclusion:

Successful operative management of superior semicircular canal dehiscence can be achieved via the transmastoid approach under local anaesthesia.
Autologous ossiculoplasty following temporal bone fracture
Authors: Wu K-C , Shu M-T , Yang C-C
Published: May 2008

Objective:

This study aimed to investigate the outcomes of autologous ossiculoplasty following temporal bone fracture.

Methods:

We analysed 10 patients who underwent autologous ossiculoplasty following temporal bone fracture from 1993 to 2006. Average results for air conduction, bone conduction and air–bone gap were calculated, using both a three- and a four-frequency average, in order to evaluate the effect of the operation.

Results:

The average follow-up time was 24.4 months. Dislocation of the incus was the most common operative finding. The average three- and four-frequency post-operative air–bone gaps were 12.0 dB (standard deviation 8.3) and 13.8 dB (standard deviation 7.7), respectively. The average air–bone gap improvements were 24.5 dB (standard deviation 13.8) and 24.4 dB (standard deviation 12.1), respectively. Eighty per cent (eight of 10) of the patients had socially acceptable hearing in the operated ear. However, only 50 per cent achieved closure of the air–bone gap to within 10 dB.

Conclusion:

Methods of maximising the stability of the reconstructed ossicular chain should be further studied.
Evaluation of irradiated salivary gland function in patients with head and neck tumours treated with radiotherapy
Authors: Baharudin A , Khairuddin A , Nizam A , Samsuddin A R
Published: May 2008

Introduction:

Radiotherapy is an important treatment modality for head and neck tumours. One of its major drawbacks is post-treatment salivary gland hypofunction. This study was performed to objectively evaluate the salivary gland function in post-irradiated head and neck tumour patients.

Methods:

We performed a cross-sectional study of 30 patients with head and neck tumours who had received radiotherapy. Unstimulated and stimulated whole salivary flow rates were assessed in these 30 patients, and compared with those of 30 normal subjects. Unstimulated whole saliva was measured by the draining method, while the spitting method was used to collect stimulated whole saliva.

Results:

Both unstimulated and stimulated whole salivary flow rates were significantly reduced in the irradiated patients, compared with the normal subjects. This difference was statistically significant (p = 0.0001).

Conclusion:

Salivary function in post-irradiated head and neck tumour patients (assessed as salivary flow rates) was significantly reduced compared with normal controls, suggesting marked salivary gland hypofunction.
Otolaryngology Department, University of Rochester Medical Center, Rochester, New York, USA, 2007
Authors: Akinpelu O V
Published: May 2008

This report summarises my visit to the otolaryngology (ORL) department of the University of Rochester Medical Center in Rochester, New York, USA, from 4 September 2007 to 29 November 2007.
Wildlife conservation payments to address habitat fragmentation and disease risks
Authors: HORAN RICHARD D. , SHOGREN JASON F. , GRAMIG BENJAMIN M.
Published: May 2008

We develop a bioeconomic model to gain insight into the challenges of Payments for Environmental Services (PES) as applied to protect endangered species given wildlife-livestock disease risks and habitat fragmentation. We show how greater connectivity of habitat creates an endogenous trade-off. More connectedness both (i) ups the chance that populations of endangered species will grow more rapidly, while (ii) simultaneously increasing the likelihood diseases will spread more quickly. We examine subsidies for habitat connectedness, livestock vaccination, and reduced movement of infected livestock. We find the cost-effective policy is to first subsidize habitat connectivity rather than vaccinations – this serves to increase habitat contiguousness. Once habitat is sufficiently connected, disease risks increase to a level to make disease-related subsidies worthwhile. Highly connected habitat requires nearly all the government budget be devoted to disease prevention and control. The result of the conservation payments is significantly increased wildlife abundance, increased livestock health and abundance, and increased development opportunities.
Can the poor participate in payments for environmental services? Lessons from the Silvopastoral Project in Nicaragua
Authors: PAGIOLA STEFANO , RIOS ANA R. , ARCENAS AGUSTIN
Published: May 2008

This paper uses data from a Payments for Environmental Services (PES) project being implemented in Nicaragua to examine the extent to which poorer households that are eligible to participate are in fact able to do so, an issue over which there has been considerable concern. The study site provides a strong test of the ability of poorer households to participate, as it requires participants to make substantial and complex land use changes. The results show that poorer households are in fact able to participate – indeed, by some measures they participated to a greater extent than better-off households. Moreover, their participation was not limited to the simpler, least expensive options. Extremely poor households had a somewhat greater difficulty in participating, but even in their case the difference is solely a relative one. Transaction costs may be greater obstacles to the participation of poorer households than household-specific constraints.
Payments for environmental services and the poor: concepts and preliminary evidence
Authors: WUNDER SVEN
Published: May 2008

Based on observations from all three tropical continents, there is good reason to believe that poor service providers can broadly gain access to payment for environmental services (PES) schemes, and generally become better off from that participation, in both income and non-income terms. However, poverty effects need to be analysed in a conceptual framework looking not only at poor service providers, but also at poor service users and non-participants. Effects on service users are positive if environmental goals are achieved, while those on non-participants can be positive or negative. The various participation filters of a PES scheme contain both pro-poor and anti-poor selection biases. Quantitative welfare effects are bound to remain small-scale, compared to national poverty-alleviation goals. Some pro-poor interventions are possible, but increasing regulations excessively could curb PES efficiency and implementation scale, which could eventually harm the poor. Prime focus of PES should thus remain on the environment, not on poverty.
Progress in coronal seismology
Authors: Roberts B.
Published: May 2008

Coronal seismology is now a well developed area of solar physics, even though many questions remain for resolution. Here we take stock of the progress made since the first direct imaging of oscillating loops was achieved through TRACE spacecraft observations in 1999.
Multilayered solar interface dynamos: from a Cartesian kinematic dynamo to a spherical dynamic dynamo
Authors: Chan Kit H. , Liao Xinhao , Zhang Keke
Published: May 2008

The existence of the solar tachocline, a thin differentially rotating layer at the base of the convection zone which is inferred from helioseismology, leads to the concept of an interface dynamo. The tachocline is magnetically coupled to the radiative interior and the overlying convection zone. A multilayered interface dynamo is required to describe the dynamo process involved. We first discuss a two-dimensional multilayered interface dynamo model in cartesian geometry consisting of four horizontal layers with different magnetic diffusivities magnetically coupled by the three sets of interface matching conditions for the generated magnetic field. Exact solutions of the coupled dynamo system are obtained in this model. We then discuss a fully three-dimensional and multi-layered spherical dynamic interface dynamo using a finite element method based on the three-dimensional tetrahedralization of the whole spherical system. The spherical dynamic interface dynamo also consists of four magnetically coupled zones. In the convection zone, the fully three-dimensional dynamic feedback of Lorentz forces is taken into account. It is shown that the dynamo is characterized by a strong toroidal magnetic field, selects dipolar symmetry and propagates equatorward.
Small-scale structure and dynamics of the lower solar atmosphere
Authors: Wedemeyer-Böhm Sven , Wöger Friedrich
Published: May 2008

The chromosphere of the quiet Sun is a highly intermittent and dynamic phenomenon. Three-dimensional radiation (magneto-)hydrodynamic simulations exhibit a mesh-like pattern of hot shock fronts and cool expanding post-shock regions in the sub-canopy part of the inter-network. This domain might be called “fluctosphere”. The pattern is produced by propagating shock waves, which are excited at the top of the convection zone and in the photospheric overshoot layer. New high-resolution observations reveal a ubiquitous small-scale pattern of bright structures and dark regions in-between. Although it qualitatively resembles the picture seen in models, more observations – e.g. with the future ALMA – are needed for thorough comparisons with present and future models. Quantitative comparisons demand for synthetic intensity maps and spectra for the three-dimensional (magneto-)hydrodynamic simulations. The necessary radiative transfer calculations, which have to take into account deviations from local thermodynamic equilibrium, are computationally very involved so that no reliable results have been produced so far. Until this task becomes feasible, we have to rely on careful qualitative comparisons of simulations and observations. Here we discuss what effects have to be considered for such a comparison. Nevertheless we are now on the verge of assembling a comprehensive picture of the solar chromosphere in inter-network regions as dynamic interplay of shock waves and structuring and guiding magnetic fields.
Inferring the chromospheric magnetic topology through waves
Authors: Hasan S. S. , Steiner O. , van Ballegooijen A.
Published: May 2008

The aim of this work is to examine the hypothesis that the wave propagation time in the solar atmosphere can be used to infer the magnetic topography in the chromosphere as suggested by Finsterle et al. (2004). We do this by using an extension of our earlier 2-D MHD work on the interaction of acoustic waves with a flux sheet. It is well known that these waves undergo mode transformation due to the presence of a magnetic field which is particularly effective at the surface of equipartition between the magnetic and thermal energy density, the β = 1 surface. This transformation depends sensitively on the angle between the wave vector and the local field direction. At the β = 1 interface, the wave that enters the flux sheet, (essentially the fast mode) has a higher phase speed than the incident acoustic wave. A time correlation between wave motions in the non-magnetic and magnetic regions could therefore provide a powerful diagnostic for mapping the magnetic field in the chromospheric network.
HXR photospheric footprints
Authors: Martínez-Oliveros J. C. , Donea A.-C. , Cally P. S.
Published: May 2008

We have analysed the 6 mHz egression power signatures of some accoustically active X-class solar flares. During the impulsive phase these flares produced conspicuous seismic signatures which have kernel-like structures, mostly aligned with the neutral line of the host active region. The kernel-like structures show the effect of constructive interference of the acoustic waves emanating from the complex sources, suggesting motion of the acoustic sources. The co-aligment between the seismic signatures and the hard X-ray emission observed by RHESSI from the footpoints of the coronal loops suggests a direct link between relativistic particles accelerated during the flare and the hydrodynamic response of the photosphere during flares.
Resonant absorption in multi-stranded coronal loops
Authors: Terradas J. , Arregui I. , Oliver R. , Ballester J. L.
Published: May 2008

We study the excitation and damping of transverse oscillations in a complex multi-stranded model of a coronal loop. By numerically solving the time-dependent magnetohydrodynamic (MHD) equations in two dimensions, we show how the global motion of the whole bundle of tubes, produced by an external disturbance, is converted into localised motions due to the process of resonant absorption. At any location in the structure two dominant frequencies are found, the frequency of the global mode (different from the kink frequency of the individual strands) and the local Alfvén frequency. The mechanism of mode conversion is not affected by the complicated geometry of the system and for certain configurations the energy conversion does not only take place at the external edge of the composite loop but also inside the structure.
Damped oscillations of two interacting coronal loops
Authors: Arregui I. , Terradas J. , Oliver R. , Ballester J. L.
Published: May 2008

We present results on the oscillatory properties (periods, damping rates, and spatial distribution of perturbations) for resonantly damped oscillations in a system of two inhomogeneous coronal slabs and compare them to the properties found in single slab loop models. A system of two identical coronal loops is modelled, in Cartesian geometry, as being composed by two density enhancements. The linear magnetohydrodynamic (MHD) wave equations for oblique propagation of waves are solved and the damping due to resonant absorption is computed. Due to the interaction between the loops, the normal modes of oscillation present in a single slab split into symmetric and antisymmetric oscillations when a system of two identical slabs is considered. The frequencies of these solutions may differ from the single slab results when the distance between the loops is of the order of a few slab widths. Oblique propagation of waves weakens this interaction, since solutions become more confined to the edges of the slabs. The damping is strong for surface-like oscillations, while sausage body-like solutions are unaffected.
A search for oscillating loops in Solar-B XRT observations
Authors: Savcheva Antonia , DeLuca Edward
Published: May 2008

Between November 2006 and March 2007, on several occasions, XRT has been taking high-cadence one or two filter observations of prominent active regions on the disk. We took these datasets and conducted a quick search for acoustic brightness oscillation in loops. We concentrated our search on flaring active regions. Here we present the preliminary results of this search. We found one active region - NOAA 10953 from 27 April - 02 May 2007 that had indications of acoustic oscillations with periods around 5 min, as well as multiples of this period, and one 40 min period that we associate with periodic heating of the loops. An interesting result is that all the loops in the active region seemed to oscillate with the same set of periods, only the power in the FFT was different and maybe dependent on the magnetic field strength.
Theoretical aspects of prominence oscillations
Authors: Oliver Ramón
Published: May 2008

The theoretical modelling of prominence vibrations has been performed mainly through the analysis of the magnetohydrodynamic normal modes of oscillation of simple equilibrium structures. Research on this topic has concentrated mostly on the oscillatory properties of prominence slabs (i.e. without taking into account the internal thread structure) and prominence fibrils (i.e. introducing some of this inherent internal complexity of prominences, although in a simplified manner). In an attempt to understand the observed strong damping of prominence oscillations, work has also been done on the attenuation of waves in these objects. The achievements in this particular research area are reviewed and some trends for possible future investigations are given.
Nonlinear Alfvén wave model of spicules and coronal heating
Authors: Kudoh Takahiro
Published: May 2008

We review the theoretical studies of the Alfvén wave model of spicules and coronal heating, mainly based on the papers by Kudoh & Shibata (1999), Saito et al. (2001) and Moriyasu et al. (2004) which performed MHD numerical simulations of nonlinear Alfvén waves propagating along a magnetic flux tube in the solar atmosphere. Kudoh & Shibata (1999) and Saito et al. (2001) found that, if the root mean square of the perturbation is greater than ~ 1 km s−1 in the photosphere, (1) the transition region is lifted up to more than ~ 5000 km (i.e., the spicule is produced), (2) the energy flux sufficient for heating the quiet corona (~ 3.0 × 105 ergs s−1 cm−2) is transported into the corona by Alfvén waves. Moriyasu et al. (2004) demonstrated that a hot corona is created in an initially cool loop as a result of the nonlinear Alfvén waves produced near the photosphere. We conclude that the nonlinear Alfvén wave model is the promising model of spicules and coronal heating.
Seismology of kink oscillations in coronal loops: Two decades of resonant damping
Authors: Goossens Marcel
Published: May 2008

The detection of rapidly damped transverse oscillations in coronal loops by Aschwanden et al. (1999) and Nakariakov et al. (1999) gave a strong impetus to the study of MHD waves and their damping. The common interpretation of the observations of these oscillations is based on kink modes. This paper reviews how the observed period and damping time can be reproduced by MHD wave theory when non-uniform equilibrium models are considered that have a transversal variation of the local Alfven velocity. The key point here is that resonant absorption cannot be avoided and occurs as natural damping mechanism for kink waves in non-uniform equilibrium models. The present paper starts with work by Hollweg & Yang (1988) and discusses subsequent developments in theory and their applications to seismology of coronal loops. It addresses the consistent use of observations of periods and damping times as seismological tools within the framework of resonant absorption. It shows that within the framework of resonant absorption infinitely many equilibrium models can reproduce the observed values of periods and damping times.
Coronal global EIT waves as tools for multiple diagnostics
Authors: Ballai I. , Douglas M.
Published: May 2008

Observations in EUV lines of the solar corona revealed large scale propagating waves generated by eruptive events able to travel across the solar disk for large distances. In the low corona, CMEs are known to generate, e.g. EIT waves which can be used to sample the coronal local and global magnetic field. This contribution presents theoretical models for finding values of magnetic field in the quiet Sun and coronal loops based on the interaction of global waves and local coronal loops as well as results on the generation and propagation of EIT waves. The physical connection between local and global solar coronal events (e.g. flares, EIT waves and coronal loop oscillations) will also be explored.
Predicting observational signatures of coronal heating by Alfvén waves and nanoflares
Authors: Antolin Patrick , Shibata Kazunari , Kudoh Takahiro , Shiota Daiko , Brooks David
Published: May 2008

Alfvén waves can dissipate their energy by means of nonlinear mechanisms, and constitute good candidates to heat and maintain the solar corona to the observed few million degrees. Another appealing candidate is the nanoflare-reconnection heating, in which energy is released through many small magnetic reconnection events. Distinguishing the observational features of each mechanism is an extremely difficult task. On the other hand, observations have shown that energy release processes in the corona follow a power law distribution in frequency whose index may tell us whether small heating events contribute substantially to the heating or not. In this work we show a link between the power law index and the operating heating mechanism in a loop. We set up two coronal loop models: in the first model Alfvén waves created by footpoint shuffling nonlinearly convert to longitudinal modes which dissipate their energy through shocks; in the second model numerous heating events with nanoflare-like energies are input randomly along the loop, either distributed uniformly or concentrated at the footpoints. Both models are based on a 1.5-D MHD code. The obtained coronae differ in many aspects, for instance, in the simulated intensity profile that Hinode/XRT would observe. The intensity histograms display power law distributions whose indexes differ considerably. This number is found to be related to the distribution of the shocks along the loop. We thus test the observational signatures of the power law index as a diagnostic tool for the above heating mechanisms and the influence of the location of nanoflares.
MHD mode conversion in a stratified atmosphere
Authors: Dee McDougall A. M. , Hood Alan W.
Published: May 2008

Mode conversion in the region where the sound and Alfvén speeds are equal is a complex process, which has been studied both analytically and numerically, and has been seen in observations. In order to further the understanding of this process we set up a simple, one-dimensional model, and examine wave propagation through this system using a combination of analytical and numerical techniques. Simulations are carried out in a gravitationally stratified atmosphere with a uniform, vertical magnetic field for both isothermal and non-isothermal cases. For the non-isothermal case a temperature profile is chosen to mimic the steep temperature gradient encountered at the transition region. In all simulations, a slow wave is driven on the upper boundary, thus propagating down from low-β to high-β plasma across the mode-conversion region. In addition, a detailed analytical study is carried out where we predict the amplitude and phase of the transmitted and converted components of the incident wave as it passes through the mode-conversion region. A comparison of these analytical predictions with the numerical results shows good agreement, giving us confidence in both techniques. This knowledge may be used to help determine wave types observed and give insight into which modes may be involved in coronal heating.
Damping of standing slow waves in hot coronal loops
Authors: Sigalotti Leonardo Di G. , Mendoza-Briceño César A. , Luna-Cardozo Marialejandra
Published: May 2008

The damping of standing slow mode oscillations in hot (T > 6 MK) coronal loops is described in the linear limit. The effects of energy dissipation by thermal conduction, viscosity, and radiative losses and gains are examined for both stratified and nonstratified loops. We find that thermal conduction acts on the way of increasing the period of the oscillations over the sound crossing time, whereas the decay times are mostly determined by viscous dissipation. Thermal conduction alone results in slower damping of the density and velocity waves compared to the observations. Only when viscosity is added do these waves damp out at the same rate of the observed SUMER loop oscillations. In the linear limit, the periods and decay times are barely affected by gravity.
High frequency oscillations in the solar chromosphere and their connection with heating
Authors: Andic Aleksandra , Mathioudakis M. , Keenan F. P. , Jess D. B. , Bloomfield D. S.
Published: May 2008

High frequency acoustic waves have been suggested as a source of mechanical heating in the quiet solar chromosphere. To investigate this, we have observed intensity oscillations of several lines in the frequency interval 1.64-70mHz using data from the VTT Tenerife and the Dunn Solar Telescope at the National Solar Observatory. Our analysis of Fe i 543.45 nm, Fe i 543.29 nm and the G-band, indicate that the majority of oscillations are connected with the magnetic fields and do not provide sufficient mechanical flux for the heating of the chromosphere. This correlation is also observed in quiet Sun areas.
Non-axisymmetric oscillations of thin twisted magnetic tubes
Authors: Ruderman Michael S.
Published: May 2008

In this paper we study non-axisymmetric oscillations of thin twisted magnetic tubes taking the density variation along the tube into account. We use the approximation of the zero-beta plasma. The magnetic field outside the tube is straight and homogeneous, however it is twisted inside the tube. We assume that the azimuthal component of the magnetic field is proportional to the distance from the tube axis, and that the tube is only weakly twisted, i.e. the ratio of the azimuthal and axial components of the magnetic field is small. Using the asymptotic analysis we show that the eigenmodes and eigenfrequencies of the kink and fluting oscillations are described by a classical Sturm-Liouville problem for a second order ordinary differential equation. The main result is that the twist does not affect the kink mode.
Identification of linear slow sausage waves in magnetic pores
Authors: Dorotovič I. , Erdélyi R. , Karlovský V.
Published: May 2008

The analysis of an 11-hour series of high resolution white light observations of a large pore in the sunspot group NOAA 7519, observed on 5 June 1993 with the Swedish Vacuum Solar Telescope at La Palma on Canary Islands, has been recently described by Dorotovičet al. (2002). Special attention was paid to the evolution of a filamentary region attached to the pore, to horizontal motions around the pore, and to small-scale morphological changes. One of the results, relevant to out work here, was the determination of temporal area evolution of the studied pore where the area itself showed a linear trend of decrease with time at an average rate of −0.23 Mm2h−1during the entire observing period. Analysing the time series of the are of the pore, there is strong evidence that coupling between the solar interior and magnetic atmosphere can occur at various scales and that the referred decrease of the area may be connected with a decrease of the magnetic field strength according to the magnetic field-to-size relation. Periods of global acoustic, e.g.p-mode, driven waves are usually in the range of 5–10 minutes, and are favourite candidates for the coupling of interior oscillations with atmospheric dynamics. However, by assuming that magneto-acoustic gravity waves may be there too, and may act as drivers, the observed periodicities (frequencies) are expected to be much longer (smaller), falling well within the mMHz domain. In this work we determine typical periods of such range in the area evolution of the pore using wavelet analysis. The resulted periods are in the range of 20–70 minutes, suggesting that periodic elements of the temporal evolution of the area of this studied pore could be linked to, and considered as, observational evidence of linear low-frequency slow sausage (magneto-acoustic gravity) waves in magnetic pores. This would give us further evidence on the coupling of global solar oscillations to the overlaying magnetic atmosphere.
Cognitive-Behavioral Therapy for Deliberate Self-Harm
Authors: Slee Nadja , Arensman Ella , Garnefski Nadia , Spinhoven Philip
Published: May 2008

Patients who engage in deliberate self-harm (DSH) form a heterogeneous population. There is a need for psychotherapeutic interventions that give therapists the flexibility to tailor the treatment plan to the needs of an individual patient. To detect essential ingredients for treatment, three different cognitive-behavioral theories of DSH will be reviewed: (1) the cognitive-behavioral theory of Linehan (1993a) , (2) the cognitive theory of Berk, Henriques, Warman, Brown, and Beck (2004) , and (3) the cognitive-behavioral theory of Rudd, Joiner, and Rajab (2001) . A review of these theories makes it possible to compare the different approaches to the essential aspects in the treatment of DSH: a trusting patient-therapist relationship, building emotion regulation skills, cognitive restructuring, and behavioral pattern breaking. An overview will be given of therapeutic techniques that can be used to address the cognitive, emotional, behavioral, and interpersonal problems associated with DSH.
Lay Theories of Suicide Among Austrian Psychology Undergraduates
Authors: Voracek Martin , Loibl Lisa Mariella , Lester David
Published: May 2008

Lester and Bean's (1992) Attribution of Causes to Suicide Scale gauges lay theories of suicide including intrapsychic problems, interpersonal conflicts, and societal forces as causes. Results obtained with its German form (n = 165 Austrian psychology undergraduates) showed no sex differences and no social-desirability effects. Intriguingly, all three subscales were moderately intercorrelated, thereby indicating respondents' general agreement (or disagreement) with all three theories. Thus, the critical dimension of lay theories of suicide appears to be the belief that suicide has definite causes (regardless of type) versus that it is without causes (unpredictable). In addition, religiosity was positively associated (and overall knowledge about suicide negatively associated) with belief in intrapsychic causes, whereas liberal political views were negatively associated with belief in interpersonal causes.
PeptideAtlas: a resource for target selection for emerging targeted proteomics workflows
Authors: Deutsch Eric W , Lam Henry , Aebersold Ruedi
Published: May 2008

A crucial part of a successful systems biology experiment is an assay that provides reliable, quantitative measurements for each of the components in the system being studied. For proteomics to be a key part of such studies, it must deliver accurate quantification of all the components in the system for each tested perturbation without any gaps in the data. This will require a new approach to proteomics that is based on emerging targeted quantitative mass spectrometry techniques. The PeptideAtlas Project comprises a growing, publicly accessible database of peptides identified in many tandem mass spectrometry proteomics studies and software tools that allow the building of PeptideAtlas, as well as its use by the research community. Here, we describe the PeptideAtlas Project, its contents and components, and show how together they provide a unique platform to select and validate mass spectrometry targets, thereby allowing the next revolution in proteomics.
No single way to understand singlet oxygen signalling in plants
Authors: Kim Chanhong , Meskauskiene Rasa , Apel Klaus , Laloi Christophe
Published: May 2008

When plant cells are under environmental stress, several chemically distinct reactive oxygen species (ROS) are generated simultaneously in various intracellular compartments and these can cause oxidative damage or act as signals. The conditional flu mutant of Arabidopsis, which generates singlet oxygen in plastids during a dark‐to‐light transition, has allowed the biological activity of singlet oxygen to be determined, and the criteria to distinguish between cytotoxicity and signalling of this particular ROS to be defined. The genetic basis of singlet‐oxygen‐mediated signalling has been revealed by the mutation of two nuclear genes encoding the plastid proteins EXECUTER (EX)1 and EX2, which are sufficient to abrogate singlet‐oxygen‐dependent stress responses. Conversely, responses due to higher cytotoxic levels of singlet oxygen are not suppressed in the ex1/ex2 background. Whether singlet oxygen levels lower than those that trigger genetically controlled cell death activate acclimation is now under investigation.
Circulating IL‐6 Concentrations and Abdominal Adipocyte Isoproterenol‐stimulated Lipolysis in Women
Authors: Morisset Anne‐Sophie , Huot Céline , Légaré Denis , Tchernof André
Published: May 2008

Objective: To examine the association of plasma interleukin‐6 (IL‐6) concentrations with adiposity and fat cell metabolism in women.

Methods and Procedures: Omental (OM) and subcutaneous (SC) adipose tissue samples were obtained from 48 healthy women (age: 47 ± 5 years, BMI: 26.9 ± 5.3 kg/m2) undergoing gynecological surgeries. Total and visceral adiposity were assessed by dual‐energy X‐ray absorptiometry and computed tomography, respectively. Measures of adipocyte lipolysis (basal, isoproterenol‐, forskolin‐, and cyclic dibutyryl‐adenosine monophosphate (AMP)‐stimulated) and adipose tissue lipoprotein lipase (LPL) activity were obtained. Plasma IL‐6 was measured by radioimmunoassay.

Results: Plasma IL‐6 was positively correlated with total body fat mass (r = 0.32, P < 0.05), SC adipose tissue area (r = 0.35, P < 0.05), SC adipocyte diameter (r = 0.30, P < 0.05), and a trend was observed with visceral adipose tissue area (r = 0.20, P < 0.07). Plasma IL‐6 was positively correlated with glycerol released in response to isoproterenol (10−5 to 10−8 mol/l) by isolated SC (0.31 ≤ r ≤ 0.65, P < 0.05) and OM (0.36 ≤ r ≤ 0.40, P < 0.02) adipocytes, independent of menopausal status. No correlation was found with LPL activity. A subsample of women with high plasma IL‐6 (n = 10) was matched with women with low plasma IL‐6 (n = 10) for total body fat mass. OM adipocyte glycerol release in response to isoproterenol (10−5 to 10−8 mol/l) was higher in the subsample of women with elevated plasma IL‐6 (P ≤ 0.07).

Discussion: We observed that OM lipolysis was significantly higher in women with elevated plasma IL‐6 for a similar body fat mass and menopausal status. These results suggest that higher circulating IL‐6 concentrations are associated with increased isoproterenol‐stimulated lipolysis especially in OM abdominal adipocytes in women.
Evaluation of Urinary Oxalate Levels in Patients Receiving Gastrointestinal Lipase Inhibitor
Authors: Sarica Kemal , Akarsu Ersin , Erturhan Sakip , Yagci Faruk , Aktaran Sebnem , Altay Bulent
Published: May 2008

Objective: The purpose of this study was to examine the possible effects of a gastrointestinal lipase inhibitor “Orlistat (Xenical)” on the intestinal absorption of oxalate and thereby on the urinary levels of oxalate excretion in overweight patients.

Methods and Procedures: Long‐term follow‐up data of 95 cases (57 men, 38 women; M/W= 1.5) were documented. Patients were randomly assigned into two groups. While the patients in group I (n = 55) were treated with orlistat (Xenical) for 6 months, patients in group II (n = 40) received no specific medication. Calcium, oxalate, and citrate levels were determined in a 24‐h urine collection from each patient. To evaluate the significance in the groups as well as the differences between the two groups, ANOVA test was performed and the results were given as mean ± s.d.

Results: Comparative evaluation of urinary oxalate levels during 3‐month follow‐up clearly showed that urinary oxalate excretion significantly increased in 34/55 patients (61.8%) in the first group (P < 0.05). Of these 34 patients, 30 (88.2%) continued to have increased urinary oxalate excretion during 6‐month follow‐up (P = 0.001). However, our data did not show any significant effect of this medication on urinary citrate and calcium levels during 3‐ and 6‐month follow‐up evaluation (P = 0.05).

Discussion: Our results suggest that increased intestinal absorption of dietary oxalate due to this type of medication in obese patients could make a substantial contribution to urinary oxalate excretion and may increase the risk of stone formation.
Obesity and Vital Exhaustion: Analysis of the Atherosclerosis Risk in the Communities Study
Authors: Bryant Maria J. , Stevens June , Truesdale Kimberly P. , Mosley Thomas , Chambless Lloyd
Published: May 2008

This study aimed to determine whether vital exhaustion (VE) was associated with BMI cross‐sectionally and after 3 and 6 years of follow‐up. Extant data from the Atherosclerosis Risk in Communities (ARIC) study were used to examine the relationship between VE and BMI among 13,727 white and African‐American adults cross‐sectionally (baseline) and longitudinally (3 and 6 years later). We used adjusted and nonadjusted general linear regression models. Associations with excess weight gain (≥5.0%) were also examined using logistic regression. Results showed that BMI was significantly higher among both white and African‐American men and women in the highest VE quartile compared to those with no VE. Similarly, high VE at baseline was associated with higher BMI 3 and 6 years later, although VE was not able to predict future BMI after adjusting for baseline BMI. Baseline VE predicted future excess weight gain in white men and women, but not in African Americans. These results suggest that reducing VE levels may play an important role in reducing the prevalence of obesity. High VE was associated with higher current BMI (all races) and excess weight gain (whites only). Although high VE predicted future weight gain without baseline BMI adjustment, the magnitude of change in BMI over time was similar among those with low and high VE; suggesting that any relationship between VE and BMI was already established at baseline. Assessment of VE and BMI over time would help to elucidate uncertainties between the temporal nature of the relationship between them.
Study of Genetic Variation in the STAT3 on Obesity and Insulin Resistance in Male Adults
Authors: Gianotti Tomas F. , Sookoian Silvia , Gemma Carolina , Burgueño Adriana L. , González Claudio D. , Pirola Carlos J.
Published: May 2008

Signal transducer and activator of transcription 3 (STAT3) plays an important role in hepatic glucose homeostasis and carbohydrate metabolism and has been implicated in the leptin‐mediated energy homeostasis. We explored whether STAT3 gene variants are associated with obesity and insulin resistance in a well‐characterized sample of 984 adult men (aged 34.4 ± 8.6 years) of self‐reported European ancestry from a population‐based study. We analyzed three tagging single‐nucleotide polymorphisms (tagSNPs), two intronic (rs2293152 and rs6503695) and one located in a noncoding region near the gene promoter (rs9891119). These variants were not associated with either obesity (in which 488 lean individuals were compared to 496 overweight/obese subjects) (P values: 0.68, 0.49, and 0.9 for rs2293152, rs6503695, and rs9891119, respectively) or BMI as a continuous trait (P values: 0.85, 0.73, and 0.58 for rs2293152, rs6503695, and rs9891119, respectively). We found no significant association between the three tagSNPs and fasting plasma glucose and insulin. Likewise, no association was observed between the homeostasis model assessment (HOMA) index and any of the tagSNPs. A significant association was observed with total cholesterol and rs6503695 (nominal P value 0.019), but after correcting for multiple testing by Bonferroni correction, the significance becomes marginal (P = 0.057). In conclusion, although STAT3 is an excellent candidate gene for assessing obesity and insulin resistance susceptibility alleles, our results do not support a major role for STAT3 variants in BMI and insulin resistance in our male population.
Substantial Changes in Epicardial Fat Thickness After Weight Loss in Severely Obese Subjects
Authors: Iacobellis Gianluca , Singh Navneet , Wharton Sean , Sharma Arya M.
Published: May 2008

We sought to evaluate the effect of weight loss on echocardiographic epicardial fat thickness, as index of visceral adiposity, and whether epicardial fat change after the weight loss can be proportionally different from overall body weight changes and related to cardiac parameters changes in severely obese subjects. This was an interventional study in 20 severely obese subjects (12 women, 8 men, BMI 45 ± 5 kg/m2, 35 ± 10 years) who underwent 6‐month very low calorie diet weight loss program. Baseline and after 6‐month weight loss anthropometrics, echocardiographic epicardial fat thickness, left ventricular mass (LVM), and diastolic function parameters were assessed. Subjects lost 20% of original body weight, BMI reduced by 19% of original BMI, waist circumference decreased by 23% of initial waist circumference. Epicardial fat thickness decreased from 12.3 ± 1.8 to 8.3 ± 1 mm P < 0.001 after the 6‐month very low calorie diet, as −32% of baseline epicardial fat thickness. LVM and diastolic function changes were better correlated with epicardial fat changes. We showed that significant weight loss can be associated with significant reduction in the epicardial fat thickness, marker of visceral adiposity in severely obese subjects. Epicardial fat decrease, therefore visceral fat decrease, can be proportionally higher than overall adiposity decrease. Epicardial fat changes are significantly associated with obesity‐related cardiac morphological and functional changes during weight loss. Measurement of echocardiographic epicardial fat thickness may provide an additional tool in understanding the metabolic risk associated with variation in fat distribution.
Reductions in Entrée Energy Density Increase Children's Vegetable Intake and Reduce Energy Intake
Authors: Leahy Kathleen E. , Birch Leann L. , Fisher Jennifer O. , Rolls Barbara J.
Published: May 2008

The energy density (ED; kcal/g) of an entrée influences children's energy intake (EI), but the effect of simultaneously changing both ED and portion size of an entrée on preschool children's EI is unknown. In this within‐subject crossover study, 3‐ to 5‐year‐old children (30 boys, 31 girls) in a daycare facility were served a test lunch once/week for 4 weeks. The amount and type of vegetables and cheeses incorporated into the sauce of a pasta entrée were manipulated to create two versions that varied in ED by 25% (1.6 or 1.2 kcal/g). Across the weeks, each version of the entrée was served to the children in each of two portion sizes (400 or 300 g). Lunch, consumed ad libitum, also included carrots, applesauce, and milk. Decreasing ED of the entrée by 25% significantly (P < 0.0001) reduced children's EI of the entrée by 25% (63.1 ± 8.3 kcal) and EI at lunch by 17% (60.7 ± 8.9 kcal). Increasing the proportion of vegetables in the pasta entrée increased children's vegetable intake at lunch by half of a serving of vegetables (P < 0.01). Decreasing portion size of the entrée by 25% did not significantly affect children's total food intake or EI at lunch. Therefore, reducing the ED of a lunch entrée resulted in a reduction in children's EI from the entrée and from the meal in both portion size conditions. Decreasing ED by incorporating more vegetables into recipes is an effective way of reducing children's EI while increasing their vegetable intake.