bluuebunny/crossref_metadata_2025 huggingface dataset:
Stürze bei älteren Erwachsenen: Risikofaktoren – Assessment – Prävention
Authors: Schott Nadja , Kurz Ann-Katrin
Published: May 2008

Zusammenfassung. Stürze gehören zu den häufigsten und komplexesten geriatrischen Syndromen. Sie tragen nicht nur zu einem beträchtlichen Anteil zur erhöhten Krankheits- und Sterberate bei, sondern auch zu funktionalen Einbußen, der Angst erneut zu stürzen sowie der frühzeitigen Einweisung in das Pflegeheim. Es lassen sich zahlreiche Ursachen und Risikofaktoren für Stürze benennen, die die Diagnose, Behandlung und Prävention zu einer schwierigen Herausforderung werden lassen. In den letzten Jahren wurde seitens der Forschung als auch der Gesundheitsversorgung das Augenmerk verstärkt auf die Identifikation effektiver Interventionen zur Vermeidung von Stürzen bzw. sturzbedingten Verletzungen bei älteren Erwachsenen gelegt. So gibt es eine ganze Anzahl randomisierter, kontrollierter Studien und systematische Reviews, die der Frage nach der günstigsten Kombination von Interventionen zur Sturzprävention nachgehen. In diesem Beitrag wird ein kurzer Überblick über die Epidemiologie von Stürzen, deren Hauptursachen und Risikofaktoren, Assessmentverfahren sowie verschiedene Interventionstypen gegeben. Abschließend werden Ergebnisse zur Effektivität eben dieser Intervention vorgestellt.
Zum Zusammenhang von berufs-, organisations- und laufbahnbezogenen Einstellungen sowie Transfermotivation und -leistung
Authors: Rowold Jens
Published: May 2008

Zusammenfassung. Die Forschung über die Wirksamkeit betrieblicher Trainings hat eine Reihe von Faktoren identifiziert, die für die Umsetzung des im Training Gelernten bei der Arbeit (Transfer) relevant sind. Aufgrund der eher fragmentarischen empirischen Befundlage sind jedoch gesicherte Einsichten in die Bedingungen des Transferprozesses bisher nur eingeschränkt möglich. Die vorliegende empirische Studie untersuchte daher eine Reihe von Merkmalen der Trainierten im Transferprozess. Auf der Basis bereits vorhandener Modelle und Studien wurde postuliert, dass berufs-, organisations- und laufbahnbezogene Einstellungen positive Zusammenhänge zur späteren Transfermotivation und -leistung aufweisen. Diese Hypothesen wurden anhand einer Call Center Stichprobe überprüft. Eine Pfadanalyse (partial least squares, PLS) belegte signifikante Zusammenhänge zwischen berufs- (z. B. Job Involvement) und karrierebezogenen (Karriereplanung) Einstellungen und Transfermotivation. Darüber hinaus stand das Konstrukt Transfermotivation im Zusammenhang mit Transferleistung. Diese Ergebnisse werden vor dem Hintergrund der veränderten Bedingungen für die Karriere diskutiert.
An event‐based comparison of two types of automated‐recording, weighing bucket rain gauges
Authors: Keefer T. O. , Unkrich C. L. , Smith J. R. , Goodrich D. C. , Moran M. S. , Simanton J. R.
Published: May 2008

A multiyear comparison of two types of automated‐recording, weighing bucket rain gauges was conducted using precipitation data collected at the United States Department of Agriculture, Agricultural Research Service's Walnut Gulch Experimental Watershed in southeastern Arizona. The comparison was part of the conversion of all rain gauges on the watershed from an analog‐recording, mechanical‐weighing rain gauge to a data logger controlled, digital‐recording, electronic‐weighing rain gauge with radiotelemetry. This comparison applied to nine pairs of analog and digital rain gauges that were in coincident operation during a 5‐year period, 1 January 2000 to 31 December 2004. This study found that (1) high errors in event intensities may be produced when analog charts are digitized at short time intervals; (2) dual digital rain gauges recorded precipitation equivalently; (3) for several different measures of precipitation, the analog and digital data were equivalent; and (4) implications for the rainfall‐runoff model, Kinematic and Erosion Runoff model (KINEROS), showed a limited but significant effect in modeled runoff due to differences between analog and digital rain gauge input precipitation intensities. This study provided a useful analysis for long‐term rain gauge networks that have recently converted, or will soon convert, from analog to digital technology. Understanding these differences and similarities will benefit interpretation of the combined long‐term precipitation record and provide insights into the impacts on hydrologic modeling.
Near‐Earth substorm features from multiple satellite observations
Authors: Lui A. T. Y. , Volwerk M. , Dunlop M. W. , Alexeev I. V. , Fazakerley A. N. , Walsh A. P. , Lester M. , Grocott A. , Mouikis C. , Henderson M. G. , Kistler L. M. , Shen C. , Shi J. K. , Zhang T. L. , Rème H.
Published: May 2008

We investigate a substorm on 3 October 2004 during which 11 satellites were located in near‐Earth magnetotail (XGSM > −10 RE). Double Star 1 (TC‐1), Cluster, and LANL‐97 satellites were closely aligned in the dawn‐dusk direction (<1 RE apart) for this conjunction. After substorm expansion onset, TC‐1 observed plasma sheet thinning at X ≈ −5.5 RE and later detected signature of plasma flow shear that may be associated with an auroral arc. Analysis of the dawn‐dusk magnetic perturbations from GOES‐10 and Polar suggests that these could be caused by a substorm current system consisting of not only the azimuthal closure of field‐aligned currents (the substorm current wedge) but also the meridional closure of field‐aligned currents. The temporal sequence of substorm activity (particle injection, current disruption, and dipolarization) revealed by these satellites indicates that the substorm expansion activity was initiated close to the Earth and spread later to further downstream distances. Furthermore, TC‐1 and Cluster data show that there is no close relationship between some dipolarizations and Earthward plasma flows in the near‐Earth region. The overall development of substorm activity is in agreement with the near‐Earth initiation model for substorms. A temporal evolution of the magnetic field reconfiguration and plasma boundary motion during this substorm is constructed from these observations.
Noise in GPS displacement measurements from Southern California and Southern Nevada
Authors: Langbein John
Published: May 2008

Time series of position changes estimated from data from 236 continuously recording GPS receivers operating in Southern California and Southern Nevada are evaluated for noise models that characterize their temporal correlations. The lengths of the time series range between 3.5 and 10 years. After adjusting these data for postseismic deformation, offsets, and annual periodicities, I find that about one‐half of the time series have temporal correlations that are categorized as either flicker or random‐walk noise. The remaining time series can be best categorized as either a combination of flicker and random‐walk; power law noise; first‐order Gauss‐Markov plus random‐walk noise; or power law plus broadband, seasonal noise. A variety of geodetic monuments are used in Southern California and Nevada, including deeply braced designs, cement piers, pins drilled in outcrop, and buildings. When I evaluate the noise for each time series in terms of an estimate of the standard error in velocity, I find that the sites with the smallest errors are those located in Nevada using deeply braced monuments. Sites that are installed within regions of active pumping, both for groundwater and oil, had the largest standard errors in velocity. Comparison of monument stability, as measured by standard error in rate, with average, annual rainfall nearby indicates a marginally significant correlation. In addition, even though regional filtering removed much of the common‐mode signals in these time series, there still remains a common‐mode seasonal signal which can and should be removed.
Isolating the role of mesoscale eddies in mixing of a passive tracer in an eddy resolving model
Authors: Booth James , Kamenkovich Igor
Published: May 2008

This study examines the role of mesoscale eddies in distribution of chlorofluorocarbon (CFC) in a numerical model of the North Atlantic. Our main conclusions are based on a comparison of two eddy‐resolving experiments, one with and one without eddy advection of CFC. The CFC distributions in these two experiments exhibit substantial differences within the subpolar gyre. In particular, in the presence of eddies the horizontal distribution of CFC in the upper 1000 m is more uniform and the CFC concentration is lower in the lower 1500 m. Our analysis demonstrates that these basin‐wide differences are caused by the interactions of eddy advection with convection and mean advection in several isolated locations. The corresponding eddy flux divergence terms are spatially non‐uniform in magnitude; their effects are often nonlocal and sometimes work against the spreading of CFC being carried out by the mean advection. These conclusions are further confirmed by a third experiment, in which the eddy advection was replaced by a down‐gradient diffusive parameterization. Our results demonstrate that advection by mesoscale eddies is crucial to the mixing of atmospheric gasses into the ocean, and outline difficulties in representing eddies by the down‐gradient diffusion.
Validation of Aura Microwave Limb Sounder HCl measurements
Authors: Froidevaux L. , Jiang Y. B. , Lambert A. , Livesey N. J. , Read W. G. , Waters J. W. , Fuller R. A. , Marcy T. P. , Popp P. J. , Gao R. S. , Fahey D. W. , Jucks K. W. , Stachnik R. A. , Toon G. C. , Christensen L. E. , Webster C. R. , Bernath P. F. , Boone C. D. , Walker K. A. , Pumphrey H. C. , Harwood R. S. , Manney G. L. , Schwartz M. J. , Daffer W. H. , Drouin B. J. , Cofield R. E. , Cuddy D. T. , Jarnot R. F. , Knosp B. W. , Perun V. S. , Snyder W. V. , Stek P. C. , Thurstans R. P. , Wagner P. A.
Published: May 2008

The Earth Observing System (EOS) Microwave Limb Sounder (MLS) aboard the Aura satellite has provided daily global HCl profiles since August 2004. We provide a characterization of the resolution, random and systematic uncertainties, and known issues for the version 2.2 MLS HCl data. The MLS sampling allows for comparisons with many (∼1500 to more than 3000) closely matched profiles from the Halogen Occultation Experiment (HALOE) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE‐FTS). These data sets provide HCl latitudinal distributions that are, overall, very similar to those from (coincident) MLS profiles, although there are some discrepancies in the upper stratosphere between the MLS and HALOE gradients. As found in previous work, MLS and ACE HCl profiles agree very well (within ∼5%, on average), but the MLS HCl abundances are generally larger (by 10–20%) than HALOE HCl. The bias versus HALOE is unlikely to arise mostly from MLS, as a similar systematic bias (of order 15%) is not observed between average MLS and balloon‐borne measurements of HCl, obtained over Fort Sumner, New Mexico, in 2004 and 2005. At the largest pressure (147 hPa) for MLS HCl, a high bias (∼0.2 ppbv) is apparent in analyses of low to midlatitude data versus in situ aircraft chemical ionization mass spectrometry (CIMS) HCl measurements from the Aura Validation Experiment (AVE) campaigns in 2004, 2005, and 2006; this bias is also observed in comparisons of MLS and aircraft HCl/O3 correlations. Good agreement between MLS and CIMS HCl is obtained at 100 to 68 hPa. The recommended pressure range for MLS HCl is from 100 to 0.15 hPa.
Synoptic assessment of water resource variability in reservoirs by remote sensing: General approach and application to the runoff harvesting systems of south India
Authors: Mialhe François , Gunnell Yanni , Mering Catherine
Published: May 2008

This paper presents a methodological procedure based on remote sensing and image analysis techniques designed to map and quantify water stocks in small irrigation reservoirs over vast, user‐defined regions. Because the method is based on unsupervised pixel classification schemes, it is analytically transparent and entirely replicable and can therefore be used in most settings as a tool for integrated water resource management, planning, or policy making, with benefits to irrigation, land use, agriculture, and water‐related social issues. Satellite images of semiarid south India are used here to quantify fluctuating water volumes in ∼2500 reservoirs. In this pilot study, the detection of temporal trends and spatial discontinuities in land use at successive dates within reservoir beds is a proxy for assessing the performance of reservoirs and for formulating hypotheses on the environmental, socioeconomic, or anthropological reasons behind the inferred levels of infrastructural maintenance or disuse. The synoptic approach paves the way for future efforts as better ground truth data become available.
Feedback between bed load transport and flow resistance in gravel and cobble bed rivers
Authors: Recking A. , Frey P. , Paquier A. , Belleudy P. , Champagne J. Y.
Published: May 2008

To calculate bed load, engineers often use flow resistance equations that provide estimates of bed shear stress. In these equations, on the basis of the estimate of the appropriate hydraulic radius associated with the bed only, the bed roughness ks is commonly set as a constant, whatever the bed load intensity. However, several studies have confirmed the existence of feedback mechanisms between flow resistance and bed load, suggesting that a flow‐dependent bed roughness should be used. Therefore, using a data set composed of 2282 flume and field experimental values, this study investigated the importance of these feedback effects. New flow resistance equations were proposed for three flow domains: domain 1 corresponds to no bed load and a constant bed roughness ks = D (where D is a representative grain diameter), whereas domain 3 corresponds to a high bed load transport rate over a flat bed with a constant bed roughness ks = 2.6D. Between these two domains, a transitional domain 2 was identified, for which the bed roughness evolved from D to 2.6D with increasing flow conditions. In this domain, the Darcy‐Weisbach resistance coefficient f can be approximated using a constant for a given slope. The results using this new flow resistance equation proved to be more accurate than those using equations obtained from simple fittings of logarithmic laws to mean values. The data set indicates that distinguishing domains 2 and 3 is still relevant for bed load. In particular, the data indicate a slope dependence in domain 2 but not in domain 3. A bed load model, based on the tractive force concept, is proposed. Finally, flow resistance and bed load equations were used together to calculate both shear stress and bed load from the flow discharge, the slope, and the grain diameter for each run of the data set. Efficiency tests indicate that new equations (implicitly taking a feedback mechanism into account) can reduce the error by a factor of 2 when compared to other equations currently in use, showing that feedback between flow resistance and bed load can improve field bed load modeling.
Temperature thresholds for bacterial symbiosis with a sponge
Authors: Webster Nicole S , Cobb Rose E , Negri Andrew P
Published: May 2008

The impact of elevated seawater temperature on bacterial communities within the marine sponge Rhopaloeides odorabile was assessed. Sponges were exposed to temperatures ranging between 27 and 33 °C. No differences in bacterial community composition or sponge health were detected in treatments between 27 and 31 °C. In contrast, sponges exposed to 33 °C exhibited a complete loss of the primary cultivated symbiont within 24 h and cellular necrosis after 3 days. Furthermore, denaturing gradient gel electrophoresis (DGGE) and clone sequence analysis detected a dramatic shift in bacterial community composition between 31 and 33 °C. Within the first 24 h most of the DGGE bands detected in samples from 27 to 31 °C were absent from the 33 °C sponges whereas eight bands were detected exclusively in the 33 °C sponges. The 16S rRNA sequencing revealed that most of the microbes from sponges exposed to 27–31 °C had highest homology to known sponge-associated bacteria. In contrast, many of the microbes from sponges exposed to 33 °C were similar to sequences previously retrieved from diseased and bleached corals. The 16S rRNA clone library analysis also detected a significant shift in bacterial community structure. The 27 °C library was composed of Proteobacteria, Actinobacteria, Nitrospira, Acidobacteria and Chloroflexi whereas the 33 °C library contained sequences from the Proteobacteria, Bacteroidetes and Firmicutes. The clear shifts in community composition at elevated temperatures can be attributed to the loss of symbionts and to the establishment of alien microbial populations including potential pathogens. Breakdown of symbioses and stress in the sponge occurred at temperatures identical to those reported for coral bleaching, indicating that sponges may be similarly threatened by climate change.
Familial Transmission of Eating Behaviors in Preschool‐aged Children
Authors: Jahnke Dörte L. , Warschburger Petra A.
Published: May 2008

To examine weight‐related differences in eating behaviors and nutrition of preschool‐aged children, the influence of maternal eating behavior on the child's eating behavior, and sex‐related differences in the transmission of eating behaviors. A total of 142 mothers of children aged 3–6 years participated. Maternal and child's eating behaviors as well as child's food consumption were assessed using questionnaires completed by mothers. Maternal BMI and child's standardized BMI (BMI‐SDS) were also calculated. More than half of the mothers were obese. Multiple regression analysis was used to predict eating behavior of the children by mothers' variables. Overweight children scored higher in external eating, food responsiveness, and speed of eating than normal‐weight children, whereas children of overweight mothers showed higher amounts of emotional eating than children of normal‐weight mothers. Maternal emotional eating (R2 = 0.19, P < 0.001) and mother's BMI (R2 = 0.07, P < 0.05) positively predicted emotional eating of sons. Maternal emotional eating (R2 = 0.19, P < 0.01) completely mediated the relation between mother's BMI and emotional eating of sons. For mother‐daughter dyads, no such relation was found. The tested model shows sex‐related differences in the transmission of maternal eating behavior which is discussed as being related to the development and maintenance of obesity.
Amyloid Precursor Protein Expression Is Upregulated in Adipocytes in Obesity
Authors: Lee Yong‐Ho , Tharp William G. , Maple Rhonda L. , Nair Saraswathy , Permana Paska A. , Pratley Richard E.
Published: May 2008

The aim of this study was to determine whether amyloid precursor protein (APP) is expressed in human adipose tissue, dysregulated in obesity, and related to insulin resistance and inflammation. APP expression was examined by microarray expression profiling of subcutaneous abdominal adipocytes (SAC) and cultured preadipocytes from obese and nonobese subjects. Quantitative real‐time PCR (QPCR) was performed to confirm differences in APP expression in SAC and to compare APP expression levels in adipose tissue, adipocytes, and stromal vascular cells (SVCs) from subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) specimens. Adipose tissue samples were also examined by western blot and immunofluorescence confocal microscopy. Microarray studies demonstrated that APP mRNA expression levels were higher in SAC (∼2.5‐fold) and preadipocytes (∼1.4) from obese subjects. Real‐time PCR confirmed increased APP expression in SAC in a separate group of obese compared with nonobese subjects (P = 0.02). APP expression correlated to in vivo indices of insulin resistance independently of BMI and with the expression of proinflammatory genes, such as monocyte chemoattractant protein‐1 (MCP‐1) (R = 0.62, P = 0.004), macrophage inflammatory protein‐1α (MIP‐1α) (R = 0.60, P = 0.005), and interleukin‐6 (IL‐6) (R = 0.71, P = 0.0005). Full‐length APP protein was detected in adipocytes by western blotting and APP and its cleavage peptides, Aβ40 and Aβ42, were observed in SAT and VAT by immunofluorescence confocal microscopy. In summary, APP is highly expressed in adipose tissue, upregulated in obesity, and expression levels correlate with insulin resistance and adipocyte cytokine expression levels. These data suggest a possible role for APP and/or Aβ in the development of obesity‐related insulin resistance and adipose tissue inflammation.
Dietary Fructose During the Suckling Period Increases Body Weight and Fatty Acid Uptake Into Skeletal Muscle in Adult Rats
Authors: Huynh Minh , Luiken Joost J.J.P. , Coumans Will , Bell Rhonda C.
Published: May 2008

Objective: The suckling period is one potentially “critical” period during which nutritional intake may permanently “program” metabolism to promote increased adult body weight and insulin resistance in later life. This study determined whether fructose introduced during the suckling period altered body weight and induced changes in fatty acid transport leading to insulin resistance in adulthood in rats.

Methods and Procedures: Pups were randomly assigned to one of four diets: suckle controls (SCs), rat milk substitute formula (Rat Milk Substitute), fructose‐containing formula (Fructose), or galactose‐containing formula (Galactose). Starting at weaning, all pups received the same diet; at 8 weeks of age, half of the SC rats began ingesting a diet containing 65% kcal fructose (SC‐Fructose). This continued until animals were 12 weeks old and the study ended.

Results: At weeks 8, 10, and 11, the Fructose group weighed more than SC and SC‐Fructose groups (P < 0.05). At weeks 8 and 10 of age, the Fructose group had significantly higher insulin concentrations vs. rats in the SC‐Fructose group. 3H‐Palmitate transport into vesicles from hind limb skeletal muscle was higher in Fructose vs. SC rats (P < 0.05). CD36 expression was increased in the sarcolemma but not in whole tissue homogenates from skeletal muscle from Fructose rats (P < 0.05) suggesting a redistribution of this protein associated with fatty acid uptake across the plasma membrane. This change in subcellular localization of CD36 is associated with insulin resistance in muscle.

Discussion: Consuming fructose during suckling may result in lifelong changes in body weight, insulin secretion, and fatty acid transport involving CD36 in muscle and ultimately promote insulin resistance.
Exercise Intensity Prescription in Obese Individuals
Authors: Pinet Bernard M. , Prud'homme Denis , Gallant Chantal A. , Boulay Pierre
Published: May 2008

The main purpose of this study was to evaluate the relationship between different methods proposed by the American College of Sports Medicine (ACSM) to prescribe exercise intensity using heart rate (HR) and oxygen uptake (VO2) in obese individuals. Sixty‐eight overweight to severely obese adults were divided into three groups (tertile) based on their BMI. The groups were T1 group (BMI = 30.5 ± 1.5, n = 23), T2 group (BMI = 34.3 ± 1.0, n = 23), and T3 group (BMI = 40.2 ± 3.7, n = 22). All subjects performed a graded exercise test using a ramp protocol on a treadmill. Individual linear regressions between %HR reserve (%HRR) and %VO2 reserve (%VO2R), %HRR and %VO2 peak (%VO2peak), %maximal HR (%HRmax) and %VO2R, and %HRmax and %VO2peak were calculated. When all the subjects were grouped together, the %HRR–%VO2R mean regression was partially related to the line of identity, while the %HRR–%VO2peak, %HRmax–%VO2R, and %HRmax–%VO2peak mean regressions were all significantly different than the line of identity (P < 0.001). The degree of obesity accounted for ∼15% of the variation for both %HRR–%VO2R and %HRR–%VO2peak mean regressions. The %HRmax–%VO2R and %HRmax–%VO2peak mean regressions were not affected by the degree of obesity but resting HR accounted for 28–37% of the variation. The relationship between the exercise intensity determined by the %HRR–%VO2R and the %HRR–%VO2peak mean regression seems to be influenced by the degree of obesity. The degree of obesity does not affect the relationship between exercise intensity generated by the %HRmax–%VO2R or %HRmax–%VO2peak equations but the resting HR does.
Depth Stratification in Illusory-Contour Figures on Heterogeneous Backgrounds is Independent of Contour Clarity and Brightness Enhancement
Authors: Guardini Pietro , Gamberini Luciano
Published: May 2008

Depth stratification in illusory-contour figures was studied by superimposing Kanizsa figures on heterogeneous backgrounds. Gaussian-noise textures were employed in two rating-scale experiments to explore observers' judgments of (i) illusory-contour clarity, (ii) brightness enhancement, and (iii) depth stratification. In experiment 1, depth stratification was found to be stronger in heterogeneous conditions. In experiment 2, texture coarseness was manipulated to determine how depth stratification is affected by linear elements of different sizes in the background, and to relate the variation to contour clarity and brightness enhancement. Results suggest that depth stratification is independent of contour clarity and brightness enhancement. Preliminary novel observations on illusory-contour formation are reported.
Expanding and Contracting Optic-Flow Patterns and Vection
Authors: Bubka Andrea , Bonato Frederick , Palmisano Stephen
Published: May 2008

When stationary observers view an optic-flow pattern, visually induced self-motion perception (vection) and a form of motion sickness known as simulator sickness (SS), can result. Previous results suggest that an expanding flow pattern leads to more SS than a contracting pattern. Sensory conflict, a possible cause of SS, may be more salient when an expanding optic-flow pattern is viewed. An experiment was conducted to test if a more salient sensory conflict accompanying expanding flow patterns might inhibit vection. Participants ( n = 15) viewed a pattern of blue squares, either steadily expanded or contracted, on a large rear-projection screen. Vection onset and magnitude were measured for 30 s with a computer-interfaced slide device. Vection onset was significantly faster, and vection magnitude stronger, when a contracting pattern was viewed. We propose that our extensive experience with forward self-motion may form a neural expectancy (exposure-history) about the sensory inputs which typically accompany expanding flow. However, since backward self-motion is less common, there may be a weaker exposure-history for contracting flow, and as a result these patterns generate less salient sensory conflict and subsequently less vection.
Age-Related Changes in Attentional Tracking of Multiple Moving Objects
Authors: Sekuler Robert , McLaughlin Chris , Yotsumoto Yuko
Published: May 2008

In a multiple-object tracking (MOT) task, young and older adults attentively tracked a subset of 10 identical, randomly moving disks for several seconds, and then tried to identify those disks that had comprised the subset. Young adults who habitually played video games performed significantly better than those who did not. Compared to young subjects (mean age = 20.6 years) with whom they were matched for video game experience, older subjects (mean age = 75.3 years) showed much reduced ability to track multiple moving objects, particularly with faster movement or longer tracking times. Control measurements with stationary disks show that the age-related decline in MOT was not caused by a general change in memory per se. To generate an item-wise performance measure, we examined older subjects' proportion correct according to the serial order in which individual disks were identified. Correct identification of target disks declined with the order in which targets were reported, suggesting that attentional tracking produced graded, rather than all-or-none, outcomes.
The α9β1 integrin enhances cell migration by polyamine-mediated modulation of an inward-rectifier potassium channel
Authors: deHart Gregory W. , Jin Taihao , McCloskey Diane E. , Pegg Anthony E. , Sheppard Dean
Published: May 2008

The α9β1 integrin accelerates cell migration through binding of spermidine/spermine acetyltransferase (SSAT) to the α9 cytoplasmic domain. We now show that SSAT enhances α9-mediated migration specifically through catabolism of spermidine and/or spermine. Because spermine and spermidine are effective blockers of K+ion efflux through inward-rectifier K+(Kir) channels, we examined the involvement of Kir channels in this pathway. The Kir channel inhibitor, barium, or knockdown of a single subunit, Kir4.2, specifically inhibited α9-dependent cell migration. α9β1 and Kir4.2 colocalized in focal adhesions at the leading edge of migrating cells and inhibition or knockdown of Kir4.2 caused reduced persistence and an increased number of lamellipodial extensions in cells migrating on an α9β1 ligand. These results identify a pathway through which the α9 integrin subunit stimulates cell migration by localized polyamine catabolism and modulation of Kir channel function.
High-pressure synthesis of the cubic perovskite BaRuO
3
and evolution of ferromagnetism in ARuO
3
(A = Ca, Sr, Ba) ruthenates
Authors: Jin C.-Q. , Zhou J.-S. , Goodenough J. B. , Liu Q. Q. , Zhao J. G. , Yang L. X. , Yu Y. , Yu R. C. , Katsura T. , Shatskiy A. , Ito E.
Published: May 2008

The cubic perovskite BaRuO
3
has been synthesized under 18 GPa at 1,000°C. Rietveld refinement indicates that the new compound has a stretched Ru–O bond. The cubic perovskite BaRuO
3
remains metallic to 4 K and exhibits a ferromagnetic transition at

T
c

= 60 K, which is significantly lower than the

T
c

≈ 160 K for SrRuO
3
. The availability of cubic perovskite BaRuO
3
not only makes it possible to map out the evolution of magnetism in the whole series of ARuO
3
(A = Ca, Sr, Ba) as a function of the ionic size of the A-site
r
A,
but also completes the polytypes of BaRuO
3
. Extension of the plot of

T
c

versus
r
A
in perovskites ARuO
3
(A = Ca, Sr, Ba) shows that

T
c

does not increase as the cubic structure is approached, but has a maximum for orthorhombic SrRuO
3
. Suppressing

T
c

by Ca and Ba doping in SrRuO
3
is distinguished by sharply different magnetic susceptibilities χ(
T
) of the paramagnetic phase. This distinction has been interpreted in the context of a Griffiths' phase on the (Ca Sr)RuO
3
side and bandwidth broadening on the (Sr,Ba)RuO
3
side.
Growth/differentiation factor 3 signals through ALK7 and regulates accumulation of adipose tissue and diet-induced obesity
Authors: Andersson Olov , Korach-Andre Marion , Reissmann Eva , Ibáñez Carlos F. , Bertolino Philippe
Published: May 2008

Growth/differentiation factor 3 (GDF3) is highly expressed in adipose tissue, and previous overexpression experiments in mice have suggested that it may act as an adipogenic factor under conditions of high lipid load. GDF3 has been shown to signal via the activin receptor ALK4 during embryogenesis, but functional receptors in adipose tissue are unknown. In this study, we show that
Gdf3
−/−
mutant mice accumulate less adipose tissue than WT animals and show partial resistance to high-fat diet-induced obesity despite similar food intake. We also demonstrate that GDF3 can signal via the ALK4-homolog ALK7 and the coreceptor Cripto, both of which are expressed in adipose tissue. In agreement with a role for ALK7 in GDF3 signaling
in vivo
, mutant mice lacking ALK7 also showed reduced fat accumulation and partial resistance to diet-induced obesity. We propose that GDF3 regulates adipose-tissue homeostasis and energy balance under nutrient overload in part by signaling through the ALK7 receptor.
Activin B receptor ALK7 is a negative regulator of pancreatic β-cell function
Authors: Bertolino Philippe , Holmberg Rebecka , Reissmann Eva , Andersson Olov , Berggren Per-Olof , Ibáñez Carlos F.
Published: May 2008

All major cell types in pancreatic islets express the transforming growth factor (TGF)-β superfamily receptor ALK7, but the physiological function of this receptor has been unknown. Mutant mice lacking ALK7 showed normal pancreas organogenesis but developed an age-dependent syndrome involving progressive hyperinsulinemia, reduced insulin sensitivity, liver steatosis, impaired glucose tolerance, and islet enlargement. Hyperinsulinemia preceded the development of any other defect, indicating that this may be one primary consequence of the lack of ALK7. In agreement with this, mutant islets showed enhanced insulin secretion under sustained glucose stimulation, indicating that ALK7 negatively regulates glucose-stimulated insulin release in β-cells. Glucose increased expression of ALK7 and its ligand activin B in islets, but decreased that of activin A, which does not signal through ALK7. The two activins had opposite effects on Ca
2+
signaling in islet cells, with activin A increasing, but activin B decreasing, glucose-stimulated Ca
2+
influx. On its own, activin B had no effect on WT cells, but stimulated Ca
2+
influx in cells lacking ALK7. In accordance with this, mutant mice lacking activin B showed hyperinsulinemia comparable with that of
Alk7
−/−
mice, but double mutants showed no additive effects, suggesting that ALK7 and activin B function in a common pathway to regulate insulin secretion. These findings uncover an unexpected antagonism between activins A and B in the control of Ca
2+
signaling in β-cells. We propose that ALK7 plays an important role in regulating the functional plasticity of pancreatic islets, negatively affecting β-cell function by mediating the effects of activin B on Ca
2+
signaling.
Alternative translation of osteopontin generates intracellular and secreted isoforms that mediate distinct biological activities in dendritic cells
Authors: Shinohara Mari L. , Kim Hye-Jung , Kim June-Ho , Garcia Virgilio A. , Cantor Harvey
Published: May 2008

Osteopontin (Opn) contributes to diverse biological processes that include immune responses, vascularization, and bone formation. Until recently, studies describing the activities of Opn have focused on the cytokine-like properties of the secreted protein. Here, we show that alternative translation of a single
Opn
mRNA species generates a secreted and intracellular isoform. Utilization of a 5′ canonical translation start site generates a protein that includes an N-terminal signal sequence allowing targeting to secretory vesicles and cytokine secretion, whereas usage of a downstream start site generates a shortened protein that lacks the N-terminal signal sequence and localizes mainly to cytoplasm. The coordinated action of these
Opn
gene products regulates the functional phenotype of subsets of dendritic cells.
Lack of aldose 1-epimerase in
Hypocrea jecorina
(anamorph
Trichoderma reesei
): A key to cellulase gene expression on lactose
Authors: Fekete Erzsébet , Seiboth Bernhard , Kubicek Christian P. , Szentirmai Attila , Karaffa Levente
Published: May 2008

The heterodisaccharide lactose (1,4-O-β-
d
-galactopyranosyl-
d
-glucose) induces cellulase formation in the ascomycete
Hypocrea jecorina
(=
Trichoderma reesei
). Lactose assimilation is slow, and the assimilation of its β-
d
-galactose moiety depends mainly on the operation of a recently described reductive pathway and depends less on the Leloir pathway, which accepts only α-
d
-galactose. We therefore reasoned whether galactomutarotase [aldose 1-epimerase (AEP)] activity might limit lactose assimilation and thus influence cellulase formation. We identified three putative AEP-encoding genes (
aep1
,
aep2
,
aep3
) in
H. jecorina
, of which two encoded intracellular protein (AEP1 and AEP2) and one encoded an extracellular protein (AEP3). Although all three were transcribed, only the
aep3
transcript was detected on lactose. However, no mutarotase activity was detected in the mycelia, their cell walls, or the extracellular medium during growth on lactose. Therefore, the effect of galactomutarotase activity on lactose assimilation was studied with
H. jecorina
strains expressing the C-terminal galactose mutarotase part of the
Saccharomyces cerevisiae
Gal10. These strains showed increased growth on lactose in a gene copy number-dependent manner, although their formation of extracellular β-galactosidase activity and transcription of the genes encoding the first steps in the Leloir and the reductive pathway was similar to the parental strain QM9414. Cellulase gene transcription on lactose dramatically decreased in these strains, but remained unaffected during growth on cellulose. Our data show that cellulase induction in
H. jecorina
by lactose requires the β-anomer of
d
-galactose and reveal the lack of mutarotase activity during growth on lactose as an important key for cellulase formation on this sugar.
Modelling heat production and energy balance in group-housed growing pigs exposed to low or high ambient temperatures
Authors: Quiniou N. , Noblet J. , van Milgen J. , Dubois S.
Published: May 2008

The effects of ambient temperature (T; 12–29°C), body weight (BW; 30–90 kg) and metabolisable energy intake (ME) on components of energy balance were studied in seven groups of Piétrain × Large White barrows kept in a respiratory chamber. In Expt 1 (groups 1, 2 and 3), T varied in a cyclic way from 22°C to 12°C and then from 12°C to 22°C with three or four consecutive days at each of 22, 19, 16, 14 and 12°C. Similarly, in Expt 2 (groups 4, 5 and 6), T varied from 19 to 29°C and then from 29 to 19°C with three or four consecutive days at each of 19, 22, 25, 27 and 29°C. In both experiments, pigs were offered feedad libitum. In Expt 3, pigs (group 7) were exposed to the thermic conditions of Expt 1 but their feed allowance was adjusted on a BW basis to thead libitumintake recorded at 19 and 22°C in Expt 1. Groups 1, 2, 4, 5 and 7 were used over two successive cycles with initial average BW of 37 kg at cycle 1 (four pigs per group) and 63 kg at cycle 2 (three pigs per group). Groups 3 and 6 were studied at an intermediary stage of growth; their initial BW was 45 kg. The O2and CO2concentrations, physical activity and feed intake were continuously and simultaneously measured and used to calculate total heat production (HP; HPtot), HP due to physical activity (HPact), activity-free HP (HP0), and thermic effect of feed. HP was modelled as a non-linear function with T, BW and ME as predictors. Results indicate that all components of HP were proportional to BW0·60. Physical activity was minimal between 19 and 27°C (8 % ME). The estimated lower critical temperature was 24°C. Between 24 and 12°C, total thermic effect of feed decreased from 31 to 16 % ME, but the short-term thermic effect of feed (5·1 % ME) remained constant. Equations for prediction of HPtot, HPactand HP0according to BW, T and ME are proposed and evaluated according to literature values; values for the feed cost of thermoregulation in pigs are proposed.
Characteristics of some wheat-based foods of the Italian diet in relation to their influence on postprandial glucose metabolism in patients with type 2 diabetes
Authors: Giacco R. , Brighenti F. , Parillo M. , Capuano M. , Ciardullo A. V. , Rivieccio A. , Rivellese A. A. , Riccardi G.
Published: May 2008

The present study was aimed at evaluating in patients with type 2 diabetes: (1) the glycaemic response to four starchy foods based on wheat, typical of the Italian diet; (2) the importance of some food characteristics in relation to their effects on postprandial glucose response. Seventeen patients with type 2 diabetes (eleven men and six women) participated in the study. All patients consumed, in random order and on alternate days, 50 g available carbohydrate provided by 90 g white bread and, according to a randomised procedure, an equivalent amount of carbohydrate provided by one (n 8) or two (n 9) of three other different test foods (g): pizza 85, potato dumplings 165, hard toasted bread 60. Foods had a similar nutrient composition. Plasma glucose response, measured for 180 min, was significantly lower after the potato dumplings than after white bread at 90 (P<0·05), 120 (P<0·01) and 150 (P<0·05) min. No difference was observed in postprandial plasma insulin response after the various test foods. The percentage of starch hydrolysed after 5 h in vitro hydrolysis with α-amylase was about 30 % lower for potato dumplings than for the other foods. However, no differences in the resistant starch content, the rate of diffusion of simple sugars added to a dialysis tube containing the food, and the viscosity of digesta were observed among the test foods. Scanning electron microscopy of potato dumplings showed a compact structure compatible with impaired accessibility of starch to digestive enzymes. In conclusion, carbohydrate-rich foods typical of the Italian diet which are often consumed as an alternative to pasta dishes are not equivalent in terms of metabolic impact in diabetic patients. Due to their low blood glucose response, potato dumplings represent a valid alternative to other starchy foods in the diabetic diet. Food structure plays an important role in determining starch accessibility to digestion, thus influencing the postprandial blood glucose response.
Susceptibility of LDL to oxidative modification in healthy volunteers supplemented with low doses ofn-3 polyunsaturated fatty acids
Authors: Higgins Siobhán , Carroll Yvonne L. , McCarthy Sinéad N. , Corridan Bernice M. , Roche Helen M. , Wallace Julie M. W. , O'Brien Nora M. , Morrissey Patrick A.
Published: May 2008

The objective of the present study was to evaluate the oxidative susceptibility of LDL in human volunteers following supplementation with various low doses (<1 g/d) ofn–3 polyunsaturated fatty acids (PUFA). Sixty-two healthy volunteers (thirty-seven males and twenty-five females, aged 19–63 years) were recruited to take part in a randomised placebo-controlled trial. Volunteers were required to take 0.9, 0.6 or 0.3 gn–3 PUFA as fish oil or placebo capsules daily for 16 weeks. Susceptibility of LDL to oxidative modification was assessed by measuring the production of conjugated dienes and thiobarbituric acid-reactive substances in LDL oxidised by Cu2+(15 μM) OR 2,2″-AZOBIS(2-AMIDINOPROPANE) DIHYDROCHLORIDE (1 Mm) for 5 h. Plasma fatty acid and LDL-fatty acid composition, cholesterol levels and antioxidant concentrations were also measured. While post-treatmentn–3 PUFA compositions of plasma and LDL reflected the capsule contents, no meaningful differences in antioxidant concentrations or cholesterol levels were observed between the groups. Supplementation with low doses ofn–3 PUFA as fish oil did not influence the oxidative susceptibility of LDL. The results of the present study suggest that moderate dietary intakes ofn–3 PUFA do not significantly influence the susceptibility of LDL to oxidative modificationin vitro.
Eicosanoid production, thrombogenic ratio, and serum and LDL peroxides in normo- and hypercholesterolaemic post-menopausal women consuming two oleic acid-rich diets with different content of minor components
Authors: Oubiña Pilar , Sánchez-Muniz Francisco J. , Ródenas Sofía , Cuesta Carmen
Published: May 2008

The present paper compares the effects of two monounsaturated oils, extra virgin olive oil (EVOO) and high-oleic acid sunflower oil (HOSO), on serum and LDL peroxides, eicosanoid production and the thrombogenic ratio (thromboxane (TX) B2:6-keto-prostaglandin F1α) in fourteen non-obese post-menopausal women. The subjects, mean age 63 (SD 11) years, were assigned to two consecutive oleic acid-rich 28 d dietary periods. EVOO and HOSO represented 62 % of the total lipid intake and were used as the only culinary fat during the first and second dietary periods respectively. Serum peroxides, plasma α-tocopherol and TXB2levels in stimulated platelet-rich plasma (PRP-TXB2) were significantly higher (P<0.01, P<0.001, and P<0.05 respectively) after the HOSO diet than after the EVOO diet. The relationship between the serum cholesterol level (<6.21 mmol/l or ≥6.21 mmol/l) and the type of dietary oil on eicosanoids, peroxides and α-tocopherol were evaluated by two-way ANOVA. Dietary oil significantly affected (P<0.05) the PRP-TXB2level, whereas serum and LDL peroxides were significantly affected (P<0.001 and P<0.01 respectively) by the serum cholesterol level. The plasma α-tocopherol level was significantly affected by the serum cholesterol level and the type of dietary oil (both P<0.001). No significant relationships were found between serum cholesterol levels, serum peroxide or LDL peroxide levels, plasma α-tocopherol concentrations or α-tocopherol intakes with eicosanoid production or the thrombogenic ratio due to dietary changes. However, in spite of their higher α-tocopherol levels, hypercholesterolaemic subjects showed increased peroxidation in serum and LDL in comparison with normocholesterolaemic subjects on the HOSO diet in comparison with the EVOO diet. These findings suggest that differences in the type of minor compounds, as well as in the concentration of linoleic acid, in both these monounsaturated oils may play an important role in modulating eicosanoid production and lipoprotein peroxidation when they constitute a large proportion of the diet of post-menopausal women.
Iron absorption from experimental infant formulas based on pea (Pisum sativum)-protein isolate: the effect of phytic acid and ascorbic acid
Authors: Davidsson Lena , Dimitriou Triantafillia , Walczyk Thomas , Hurrell Richard F.
Published: May 2008

Infant formula based on pea (Pisum sativum)-protein isolate has been suggested as an alternative to soyabean formula in countries where soyabean is not a native crop, or when soyabean protein cannot be used due to allergic reactions or intolerances. In the present study, Fe absorption from experimental infant formulas based on pea-protein isolate was measured in healthy non-anaemic young women. The influence of phytic acid and ascorbic acid on Fe absorption was evaluated, using a stable-isotope technique based on incorporation of Fe stable-isotope labels into erythrocytes 14 d after administration. Geometric mean Fe absorption increased from 20·7 (+1SD 41·6, -1sd 10·3) % to 33·1 (+1sd 58·6, -1sd 18·7) %; (P<0·0001; n 10) after enzymic degradation of virtually all phytic acid. Doubling the molar ratio Fe : ascorbic acid from 1 : 2·1 to 1 : 4·2 in the infant formula with native phytic acid content also increased Fe absorption significantly (P<0·0001; n 10); geometric mean Fe absorption increased from 14·8 (+1sd 32·1, -1sd 6·8) % to 22·1 (+1sd 47·2, -1sd 10·4) %. These results confirm the inhibitory and enhancing effects of phytic acid and ascorbic acid respectively on Fe absorption, but also indicate relatively high fractional Fe absorption from the pea-protein-based formulas. After adjusting for differences in Fe status, our data indicate that Fe absorption from dephytinised pea protein might be less inhibitory than dephytinised soyabean protein as measured in a previous study ().
Divergent changes in serum sterols during a strict uncooked vegan diet in patients with rheumatoid arthritis
Authors: Ågren J. J. , Tvrzicka E. , Nenonen M. T. , Helve T. , Hänninen O.
Published: May 2008

The effects of a strict uncooked vegan diet on serum lipid and sterol concentrations were studied in patients with rheumatoid arthritis. The subjects were randomized into a vegan diet group (n16), who consumed a vegan diet for 2–3 months, or into a control group (n13), who continued their usual omnivorous diets. Serum total and LDL-cholesterol and -phospholipid concentrations were significantly decreased by the vegan diet. The levels of serum cholestanol and lathosterol also decreased, but serum cholestanol:total cholesterol and lathosterol:total cholesterol did not change. The effect of a vegan diet on serum plant sterols was divergent as the concentration of campesterol decreased while that of sitosterol increased. This effect resulted in a significantly greater sitosterol:campesterol value in the vegan diet group than in the control group (1.48 (SD 0.39)V.0.72 (sd 0.14); P<0.001). A higher concentration of campesterol compared with sitosterol is normal in omnivorous subjects and can be explained by lower absorption and esterification rates of sitosterol. Our results suggest that a strict uncooked vegan diet changes the relative absorption rates of these sterols and/or their biliary clearance.