bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chick production at the largest emperor penguin colony decreases by 50% from 2008–10
Authors: Kooyman G.L. , Ponganis P.J. 
Published: July 2013

AbstractThe emperor penguin colony at Coulman Island is reputedly the largest known. This reputation is based on intermittent ground and aerial surveys performed since 1958. From an aerial survey obtained on 28 October 2010 we discovered that the total number of chicks was 56% of the lowest previous estimate of 2006 and only 41% of the most recent estimate in 2008. All of the counts tallied since 1983 were determined either by ground counts or from aerial film or digital photographs, or estimates from adult counts. We also determined the sea ice conditions in autumn, which is close to the time the adults arrive to breed. We present three hypotheses of what might have happened from 2008–10 to cause the step change in chick production, the small recovery of chick numbers in 2011, and the complete recovery of number of adults from 2010–11. We conclude that local circumstances may have strongly influenced the breeding behaviour of the emperor penguins in 2010 and to a lesser degree in 2011 when many adults elected not to breed.
A clinical manifestation-based prediction of haemodynamic patterns of orthostatic intolerance in children: a multi-centre study
Authors: Chen Li , Li Xueying , Todd Ochs , Wang Cheng , Jin Hongfang , Du Junbao 
Published: July 2013

AbstractObjective: At present, the haemodynamic diagnosis of orthostatic intolerance is based mainly on the head-up tilt table test, which is sometimes risky for patients. Thus, it is important to find objective and safe methods to differentiate haemodynamic patterns of orthostatic intolerance cases. Methods: In all, 629 children with orthostatic intolerance, either vasovagal syncope or postural orthostatic tachycardia syndrome, were included in the multi-centre clinical study. We analysed the association between the clinical manifestation and haemodynamic patterns of the patients. Results: Syncope after motion with a prodrome of chest distress or palpitations and the concomitant symptom(s) after a syncopal attack, with debilitation, dizziness or headache, were the most important variables in predicting the diagnosis of vasovagal syncope. The overall diagnostic accuracy was 71.5%. Conclusion: Complaint of syncope after motion with prodromal chest distress or palpitation and the concomitant symptom after a syncopal attack, with subsequent debilitation, dizziness or headache, were the most important variables in the diagnosis of vasovagal syncope in children with orthostatic intolerance.
Cognition in Early Relapsing-Remitting Multiple Sclerosis: Consequences May Be Relative to Working Memory
Authors: Berrigan Lindsay I. , LeFevre Jo-Anne , Rees Laura M. , Berard Jason , Freedman Mark S. , Walker Lisa A.S. 
Published: July 2013

AbstractThe Relative Consequence Model proposes multiple sclerosis (MS) patients have a fundamental deficit in processing speed that compromises other cognitive functions. The present study examined the mediating role of processing speed, as well as working memory, in the MS-related effects on other cognitive functions for early relapsing-remitting patients. Seventy relapsing-remitting MS patients with disease duration not greater than 10 years and 72 controls completed tasks assessing processing speed, working memory, learning, and executive functioning. The possible mediating roles of speed and working memory in the MS-related effects on other cognitive functions were evaluated using structural equation modeling. Processing speed was not significantly related to group membership and could not have a mediating role. Working memory was related to group membership and functioned as a mediating/intervening factor. The results do not support the Relative Consequence Model in this sample and they challenge the notion that working memory impairment only emerges at later disease stages. The results do support a mediating/intervening role of working memory. These results were obtained for early relapsing-remitting MS patients and should not be generalized to the broader MS population. Instead, future research should examine the relations that exist at other disease stages. (JINS, 2013, 19, 1–12)
Quantifying Cognitive Reserve in Older Adults by Decomposing Episodic Memory Variance: Replication and Extension
Authors: Zahodne Laura B. , Manly Jennifer J. , Brickman Adam M. , Siedlecki Karen L. , DeCarli Charles , Stern Yaakov 
Published: July 2013

AbstractThe theory of cognitive reserve attempts to explain why some individuals are more resilient to age-related brain pathology. Efforts to explore reserve have been hindered by measurement difficulties. Reed et al. (2010) proposed quantifying reserve as residual variance in episodic memory performance that remains after accounting for demographic factors and brain pathology (whole brain, hippocampal, and white matter hyperintensity volumes). This residual variance represents the discrepancy between an individual's predicted and actual memory performance. The goals of the present study were to extend these methods to a larger, community-based sample and to investigate whether the residual reserve variable is explained by age, predicts longitudinal changes in language, and predicts dementia conversion independent of age. Results support this operational measure of reserve. The residual reserve variable was associated with higher reading ability, lower likelihood of meeting criteria for mild cognitive impairment, lower odds of dementia conversion independent of age, and less decline in language abilities over 3 years. Finally, the residual reserve variable moderated the negative impact of memory variance explained by brain pathology on language decline. This method has the potential to facilitate research on the mechanisms of cognitive reserve and the efficacy of interventions designed to impart reserve. (JINS, 2013, 19, 1–9)
Serum ferritin contributes to racial or geographic disparities in metabolic syndrome in Taiwan
Authors: Chang Jung-Su , Lin Shiue-Ming , Chao Jane C-J , Chen Yi-Chun , Wang Chi-Mei , Chou Ni-Hsin , Pan Wen-Harn , Bai Chyi-Huey 
Published: July 2013

AbstractObjectivesAsians and Pacific Islanders have higher circulating serum ferritin (SF) compared with Caucasians but the clinical significance of this is unclear. There is a higher prevalence of metabolic syndrome (MetS) in Taiwanese Indigenous than Han Chinese. Genetically, Indigenous are related to Austronesians and account for 2 % of Taiwan's population. We tested the hypothesis that accumulation of Fe in the body contributes to the ethnic/racial disparities in MetS in Taiwan.DesignA population-based, cross-sectional study.SettingNational Nutrition and Health Survey in Taiwan and Penghu Island.SubjectsA total of 2638 healthy adults aged ≥19 years. Three ethnic groups were included.ResultsHan Chinese and Indigenous people had comparable levels of SF. Austronesia origin was independently associated with MetS (OR = 2·61, 95 % CI 2·02, 3·36). After multiple adjustments, the odds for MetS (OR = 2·49, 95 % CI 1·15, 5·28) was significantly higher among Indigenous people in the highest SF tertile compared with those in the lowest tertile. Hakka and Penghu Islanders yielded the lowest risks (OR = 1·08, 95 % CI 0·44, 2·65 and OR = 1·21, 95 % CI 0·52, 2·78, respectively). Indigenous people in the highest SF tertile had increased risk for abnormal levels of fasting glucose (OR = 2·34, 95 % CI 1·27, 4·29), TAG (OR = 1·94, 95 % CI 1·11, 3·39) and HDL-cholesterol (OR = 2·10, 95 % CI 1·18, 3·73) than those in the lowest SF tertile.ConclusionsOur results raise the possibility that ethnic/racial differences in body Fe store susceptibility may contribute to racial and geographic disparities in MetS.
Macronutrient intake and type 2 diabetes risk in middle-aged Australian women. Results from the Australian Longitudinal Study on Women's Health
Authors: Alhazmi Amani , Stojanovski Elizabeth , McEvoy Mark , Garg Manohar L 
Published: July 2013

AbstractObjectiveTo investigate the association between macronutrient intake and type 2 diabetes risk in middle-aged Australian women.DesignA prospective cohort study, with 6 years (2002–2007) of follow up. Dietary intake was assessed with a validated FFQ. Relative risks with 95 % confidence intervals were used to examine risk associations.SettingAustralian Longitudinal Study on Women's Health, Australia.SubjectsAustralian women (n 8370) from the Australian Longitudinal Study on Women's Health aged 45–50 years and free of type 2 diabetes at baseline.ResultsAfter 6 years of follow-up, 311 women developed type 2 diabetes. After adjusting for sociodemographic, lifestyle and other dietary risk factors, MUFA, total n-3 PUFA, α-linolenic acid and total n-6 PUFA intakes were positively associated with the incidence of type 2 diabetes. The relative risks for type 2 diabetes for the highest compared with the lowest quintiles were 1·64 (95 % CI 1·06, 2·54), P = 0·04 for MUFA; 1·55 (95 % CI 1·03, 2·32), P = 0·01 for n-3 PUFA; 1·84 (95 % CI 1·25, 2·71), P < 0·01 for α-linolenic acid; and 1·60 (95 % CI 1·03, 2·48), P = 0·04 for n-6 PUFA. Other dietary macronutrients were not significantly associated with diabetes risk.ConclusionsThe data indicate that consumption of MUFA, n-3 PUFA and n-6 PUFA may influence the risk of developing type 2 diabetes in women.
BALANCE FOR TATE COHOMOLOGY WITH RESPECT TO SEMIDUALIZING MODULES
Authors: LIANG LI , YANG GANG 
Published: July 2013

AbstractIn this paper, we further study Tate cohomology of modules over a commutative ring with respect to semidualizing modules using the ideals of Sather-Wagstaff et al. [‘Tate cohomology with respect to semidualizing modules’, J. Algebra 324 (2010), 2336–2368]. In particular, we prove a balance result for the Tate cohomology ${\widehat{\mathrm{Ext} }}^{n} $ for any $n\in \mathbb{Z} $. This result complements the work of Sather-Wagstaff et al., who proved that the result holds for any $n\geq 1$. We also discuss some vanishing properties of Tate cohomology.
Microlocal Euler classes and Hochschild homology
Authors: Kashiwara Masaki , Schapira Pierre 
Published: July 2013

AbstractWe define the notion of a trace kernel on a manifold $M$. Roughly speaking, it is a sheaf on $M\times M$ for which the formalism of Hochschild homology applies. We
associate a microlocal Euler class with such a kernel, a cohomology class with values
in the relative dualizing complex of the cotangent bundle ${T}^{\ast } M$ over $M$, and we prove that this class is functorial with respect to the
composition of kernels.This generalizes, unifies and simplifies various results from (relative) index
theorems for constructible sheaves, $\mathscr{D}$-modules and elliptic pairs.
Unipotent differential algebraic groups as parameterized differential Galois groups
Authors: Minchenko Andrey , Ovchinnikov Alexey , Singer Michael F. 
Published: July 2013

AbstractWe deal with aspects of direct and inverse problems in parameterized Picard–Vessiot (PPV) theory. It is known that, for certain fields, a linear differential algebraic group (LDAG)$G$is a PPV Galois group over these fields if and only if$G$contains a Kolchin-dense finitely generated group. We show that, for a class of LDAGs$G$, including unipotent groups,$G$is such a group if and only if it has differential type$0$. We give a procedure to determine if a parameterized linear differential equation has a PPV Galois group in this class and show how one can calculate the PPV Galois group of a parameterized linear differential equation if its Galois group has differential type$0$.
Flux-transport and mean-field dynamo theories of solar cycles
Authors: Choudhuri Arnab Rai 
Published: July 2013

AbstractWe point out the difficulties in carrying out direct numerical simulation of the solar dynamo problem and argue that kinematic mean-field models are our best theoretical tools at present for explaining various aspects of the solar cycle in detail. The most promising kinematic mean-field model is the flux transport dynamo model, in which the toroidal field is produced by differential rotation in the tachocline, the poloidal field is produced by the Babcock–Leighton mechanism at the solar surface and the meridional circulation plays a crucial role. Depending on whether the diffusivity is high or low, either the diffusivity or the meridional circulation provides the main transport mechanism for the poloidal field to reach the bottom of the convection zone from the top. We point out that the high-diffusivity flux transport dynamo model is consistent with various aspects of observational data. The irregularities of the solar cycle are primarily produced by fluctuations in the Babcock–Leighton mechanism and in the meridional circulation. We summarize recent work on the fluctuations of meridional circulation in the flux transport dynamo, leading to explanations of such things as the Waldmeier effect.
Solar-cycle precursors and predictions
Authors: Jiang Jie 
Published: July 2013

AbstractThe sunspot number data during the past 400 years indicates that both the profile and the amplitude of the solar cycle have large variations. Some precursors of the solar cycle were identified aiming to predict the solar cycle. The polar field and the geomagnetic index are two precursors which are received the most attention. The geomagnetic variations during the solar minima are potentially caused by the solar polar field by the connection of the solar open flux. The robust prediction skill of the polar field indicates that the memory of the dynamo process is less than 11 yrs based on the frame of the Babcock-Leighton flux transport dynamo. One possible reason to get the short magnetic memory is the high magnetic diffusivity in the convective zone. Our recent studies show that the radial downward pumping is another possible reason. Based upon the mechanism, we well simulate the cycle irregularities during RGO time period. This opens the possibility to set up a standard dynamo based model to predict the solar cycle. In the end, the no correlation between the polar field and the preceding cycle strength due to two nonlinearities involved in the sunspot emergence will be stressed.
Digitization of Spörer's sunspot drawings
Authors: Diercke Andrea , Arlt Rainer , Denker Carsten 
Published: July 2013

AbstractMuch of our knowledge about the solar dynamo is based on sunspot observations. It is thus desirable to extend the set of positional and morphological data of sunspots into the past. Gustav Spörer observed in Germany from Anklam (1861–1873) and Potsdam (1874–1894). He left detailed prints of sunspot groups, which we digitized and processed to mitigate artifacts left in the print by the passage of time. After careful geometrical correction, the sunspot data are now available as synoptic charts for almost 450 solar rotation periods. Individual sunspot positions can thus be precisely determined and spot areas can be accurately measured using morphological image processing techniques. These methods also allow us to determine tilt angles of active regions (Joy's law) and to assess the complexity of an active region.
Dependence of solar cycles duration on the magnitude of the annual module of the sunspots magnetic field
Authors: Krivodubskij Valery N. , Lozitska Natalia I. 
Published: July 2013

AbstractThe dependence of the solar cycle duration, T, on the 3 years averaged module of the large-scale sunspots magnetic fields (30-60 arcsec), Bsp index, was investigated on the base of about 10,000 visual observations conducted during last eight (16-23) cycles. It was found that the duration T of the investigated cycles linearly depends on the index Bsp of the magnetic fields observed during 3 years on decline phase of the solar cycle (second, third and fourth years after solar maximum Tmax). Namely, the duration of the cycles T was varied between 9,5 and 12,5 years, when the magnetic index Bsp was ranged from 2450 to 2600 G. An explanation for this dependence is proposed within the framework of non-linear αΩ- dynamo model. We found the following equation for the dependence of solar dynamo-period on magnetic index: T ≈ Bsp3/2. Therefore, the large observed index Bsp, the longer calculated period T.
Solar cycle and quasi-biennial variations in helioseismic frequencies
Authors: Tripathy Sushanta C. , Jain Kiran , Simoniello Rosaria , Hill Frank , Turck-Chièze Sylvaine 
Published: July 2013

AbstractThe prolonged period of solar minimum between cycles 23 and 24 has invoked a great deal of interest to understand the origin of the unusually low solar activity. Even though the origin of solar activity is believed to lie in the shear layer at the base of the convection zone, the analysis of helioseismic data seem to orientate us toward the near surface. In this context, we analyze the signature of the quasi-biennial periodicity seen in the oscillation frequencies which may provide additional constraints on the solar dynamo models.
Interplanetary scintillation signatures in the inner heliosphere of the deepest solar minimum in the past 100 years
Authors: Bisoi Susanta Kumar , Janardhan P. 
Published: July 2013

AbstractWe have used interplanetary scintillation (IPS) observations at 327 MHz spanning years 1983-2009 to study microturbulence levels in the inner heliosphere. We find that the microturbulence levels show a steady and significant drop in the entire inner heliosphere starting from around 1995. The fact that the solar polar fields have also shown a similar declining trend provides a consistent result showing the buildup to the solar minimum between the solar cycles 23 and 24, the deepest in the past 100 years, actually began more than a decade earlier.
Asymmetry in the periodicities of solar photospheric fields: A probe to the unusual solar minimum prior to cycle 24
Authors: Bisoi Susanta Kumar , Janardhan P. 
Published: July 2013

AbstractEmploying wavelet and Fourier methods, we investigate temporal variations of periodicities in the photospheric fields obtained from synoptic magnetograms of the National Solar Observatory at Kitt Peak (NSO/KP) spanning the years 1975-2009. A north-south asymmetry is noticed in the periodicities of photospheric fields in the latitude range, 45°-78°, when the data is grouped into fields prior to and after 1996. This asymmetry when coupled with the fact that both solar fields in the latitude range, 45°-78°, and the micro-turbulence levels in the inner heliosphere began declining ~ 1995-1996 suggests that active changes occurred in the underlying basic solar processes which eventually initiated, at the end of solar cycle 23, the build-up of the deepest solar minimum, in the past 100 years.
Solar magneto-convection
Authors: Schüssler Manfred 
Published: July 2013

AbstractAn overview is given about recent developments and results of comprehensive simulations of magneto-convective processes in the near-surface layers and photosphere of the Sun. Simulations now cover a wide range of phenomena, from whole active regions, over individual sunspots and pores, magnetic flux concentrations and vortices in intergranular lanes, down to the intricate mixed-polarity structure of the magnetic field generated by small-scale dynamo action. The simulations in concert with high-resolution observations have provided breakthroughs in our understanding of the structure and dynamics of the magnetic fields in the solar photosphere.
Solar cycle variation of helicity characteristics indicated by SP/Hinode
Authors: Hao Juan , Zhang Mei 
Published: July 2013

AbstractHelicity characteristics in active regions (ARs) are studied, using so far the most accurate vector magnetic field measurements obtained with SP/Hinode. Our sample includes all ARs observed by SP/Hinode, up to June 2012. The sample is divided into three sub-samples: Cycle 23 (from 2006.11 to 2008.06), Cycle 24a (from 2008.10 to 2010.09) and Cycle 24b (from 2010.10 to 2012.06). We confirm our previous findings that the usual hemispheric helicity sign rule is not obeyed in the descending phase of solar cycle 23 and is obeyed in the ascending phase of solar cycle 24. And we find that the second phase of the solar cycle 24 (Cycle 24b) shows an even stronger evidence of the usual hemispheric helicity sign rule than its first phase (Cycle 24a). It is also found that our previous finding that the strong and weak fields possess the opposite helicity signs is not followed in Cycle 24b, whereas it is weakly followed in Cycle 24a and strongly followed in the descending phase of Cycle 23. This means that this rule also has a solar cycle variation, in addition to the solar cycle variation of the usual hemispheric helicity sign rule, and there is a roughly 2-years time delay between the two.
Role of longitudinal activity complexes for solar and stellar dynamos
Authors: Mantere Maarit J. , Käpylä Petri J. , Pelt Jaan 
Published: July 2013

AbstractIn this paper we first discuss observational evidence of longitudinal concentrations of magnetic activity in the Sun and rapidly rotating late-type stars with outer convective envelopes. Scenarios arising from the idea of rotationally influenced anisotropic convective turbulence being the key physical process generating these structures are then presented and discussed - such effects include the turbulent dynamo mechanism, negative effective magnetic pressure instability (NEMPI) and hydrodynamical vortex instability. Finally, we discuss non-axisymmetric stellar mean-field dynamo models, the results obtained with them, and compare those with the observational information gathered up so far. We also present results from a pure α2 mean-field dynamo model, which show that time-dependent behavior of the dynamo solutions can occur both in the form of an azimuthal dynamo wave and/or oscillatory behavior related to the alternating energy levels of the active longitudes.
The gap of differential rotation in early F-type stars
Authors: Eiff Matthias Ammler-von , Reiners Ansgar 
Published: July 2013

AbstractWe present new measurements of the rotational profile of 56 nearby stars of spectral types A-F obtained by line profile analysis. Together with earlier work, we now know of 33 stars in which Sun-like differential rotation was identified by line profile analysis. We find evidence of two populations of differential rotators, one group of rapidly rotating A stars at the granulation boundary with strong horizontal shear, and another group of mid- to late-F type stars with moderate rates of rotation and less shear. There is a gap between A and F stars, in which the stars appear to exhibit very little shear. Apparently, the physical conditions of differential rotation change at early-F spectral types.
CoRot observation of a young Sun-like star
Authors: Gondoin P. , Gandolfi D. , Fridlund M. , Guenther E. W. , Hatzes A. 
Published: July 2013

AbstractThe present study reports measurements of the rotation period of a young solar analogue, estimates of its surface coverage by photospheric starspots and of its chromospheric activity level, and derivations of its evolutionary status. It compares the chromospheric activity level of this young star with a model of chromospheric activity evolution established by combining relationships between the R′HK index and the Rossby number with a recent model of stellar rotation evolution on the main-sequence.
Magnetic activity and solar-like pulsations of X-ray sources in the Kepler field of view
Authors: Molenda-Żakowicz Joanna , Frasca Antonio , Fröhlich Hans-Erich 
Published: July 2013

AbstractWe report on cross-matching the ROSAT All-Sky Survey and the XMM-Newton catalogs with the Kepler Input Catalog (KIC). For several stars associated with X-ray sources, we provide also an access to our high-resolution spectroscopic observations.