bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of the satellite radar altimeter sea ice thickness retrieval uncertainty
Authors: Tonboe R. T. , Pedersen L. T. , Haas C.
Published: April 2010

Abstract. Although it is well known that radar waves penetrate into snow and sea ice, the exact mechanisms for radar-altimeter scattering and its link to the depth of the effective scattering surface from sea ice are still unknown. Previously proposed mechanisms linked the snow ice interface, i.e. the dominating scattering horizon, directly with the depth of the effective scattering surface. However, simulations using a multilayer radar scattering model show that the effective scattering surface is affected by snow-cover and ice properties. With the coming Cryosat-2 (planned launch 2009) satellite radar altimeter it is proposed that sea ice thickness can be derived by measuring its freeboard. In this study we evaluate the radar altimeter sea ice thickness retrieval uncertainty in terms of floe buoyancy, radar penetration and ice type distribution using both a scattering model and ''Archimedes' principle''. The effect of the snow cover on the floe buoyancy and the radar penetration and on the ice cover spatial and temporal variability is assessed from field campaign measurements in the Arctic and Antarctic. In addition to these well known uncertainties we use high resolution RADARSAT SAR data to simulate errors due to the variability of the effective scattering surface as a result of the sub-footprint spatial backscatter and elevation distribution sometimes called preferential sampling. In particular in areas where ridges represent a significant part of the ice volume (e.g. the Lincoln Sea) the simulated altimeter thickness estimate is lower than the real average footprint thickness. This means that the errors are large, yet manageable if the relevant quantities are known a priori. A discussion of the radar altimeter ice thickness retrieval uncertainties concludes the paper.
Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years
Authors: Cook A. J. , Vaughan D. G.
Published: April 2010

Abstract. In recent decades, seven out of twelve ice shelves around the Antarctic Peninsula (AP) have either retreated significantly or have been almost entirely lost. At least some of these retreats have been shown to be unusual within the context of the Holocene and have been widely attributed to recent atmospheric and oceanic changes. To date, measurements of the area of ice shelves on the AP have either been approximated, or calculated for individual shelves over dissimilar time intervals. Here we present a new dataset containing up-to-date and consistent area calculations for each of the twelve ice shelves on the AP over the past five decades. The results reveal an overall reduction in total ice-shelf area by over 28 000 km2 since the beginning of the period. Individual ice shelves show different rates of retreat, ranging from slow but progressive retreat to abrupt collapse. We discuss the pertinent features of each ice shelf and also broad spatial and temporal patterns in the timing and rate of retreat. We believe that an understanding of this diversity and what it implies about the baseline dynamics and control will provide the best foundation for developing a reliable real predictive skill.
Quasi-3-D resistivity imaging – mapping of heterogeneous frozen ground conditions using electrical resistivity tomography
Authors: Kneisel C. , Bast A. , Schwindt D.
Published: April 2010

Abstract. Up to now an efficient 3-D geophysical mapping of the subsurface in mountainous environments with rough terrain has not been possible. A merging approach of several closely spaced 2-D electrical resistivity tomography (ERT) surveys to build up a quasi-3-D model of the electrical resistivity is presented herein as a practical compromise for inferring subsurface characteristics and lithology. The ERT measurements were realised in a small glacier forefield in the Swiss Alps with complex terrain exhibiting a small scale spatial variability of surface substrate. To build up the grid for the quasi-3-D measurements the ERT surveys were arranged as parallel profiles and perpendicular tie lines. The measured 2-D datasets were collated into one quasi-3-D file. A forward modelling approach – based on studies at a permafrost site below timberline – was used to optimize the geophysical survey design for the mapping of the mountain permafrost distribution in the investigated glacier forefield. Quasi-3-D geoelectrical imaging is a useful method for mapping of heterogeneous frozen ground conditions and can be considered as a further milestone in the application of near surface geophysics in mountain permafrost environments.
Spatial and temporal variability of snow depth and SWE in a small mountain catchment
Authors: Grünewald T. , Schirmer M. , Mott R. , Lehning M.
Published: April 2010

Abstract. The spatio-temporal variability of the mountain snow cover determines the avalanche danger, snow water storage, permafrost distribution and the local distribution of fauna and flora. Using a new type of terrestrial laser scanner (TLS), which is particularly suited for measurements of snow covered surfaces, snow depth, snow water equivalent (SWE) and melt rates have been monitored in a high alpine catchment during an ablation period. This allowed for the first time to get a high resolution (2.5 m cell size) picture of spatial variability and its temporal development. A very high variability in which maximum snow depths between 0–9 m at the end of the accumulation season was found. This variability decreased during the ablation phase, although the dominant snow deposition features remained intact. The spatial patterns of calculated SWE were found to be similar to snow depth. Average daily melt rate was between 15 mm/d at the beginning of the ablation period and 30 mm/d at the end. The spatial variation of melt rates increased during the ablation rate and could not be explained in a simple manner by geographical or meteorological parameters, which suggests significant lateral energy fluxes contributing to observed melt. It could be qualitatively shown that the effect of the lateral energy transport must increase as the fraction of snow free surfaces increases during the ablation period.
Modelling snowdrift sublimation on an Antarctic ice shelf
Authors: Lenaerts J. T. M. , van den Broeke M. R. , Déry S. J. , König-Langlo G. , Ettema J. , Kuipers Munneke P.
Published: April 2010

Abstract. In this paper, we estimate the contribution of snowdrift sublimation (SUds) to the surface mass balance at Neumayer, located on the Ekström ice shelf in Eastern Antarctica. A single column version of the RACMO2-ANT model is used as a physical interpolation tool of high-quality radiosonde and surface measurements for a 15 yr period (1993–2007), and combined with a routine to calculate snowdrift sublimation and horizontal snow transport. The site is characterised by a relatively mild, wet and windy climate, so snowdrift is a common phenomenon. The modelled timing and frequency of snowdrift events compares well with observations. This is further illustrated by an additional simulation for Kohnen base, where the timing of snowdrift is realistic, although the modelled horizontal transport is overestimated. Snowdrift sublimation is mainly dependent on wind speed, but also on relative humidity and temperature. During high wind speeds, SUds saturates and cools the air, limiting its own strength. We estimate that SUds removes around 16%±8% of the accumulated snow from the surface. The total sublimation more than triples when snowdrift is considered, although snowdrift sublimation limits sublimation at the surface. SUds shows a strong seasonal cycle, as well as large inter-annual variability. This variability can be related to the variability of the atmospheric conditions in the surface layer.
The effect of more realistic forcings and boundary conditions on the modelled geometry and sensitivity of the Greenland ice-sheet
Authors: Stone E. J. , Lunt D. J. , Rutt I. C. , Hanna E.
Published: April 2010

Abstract. Ice thickness and bedrock topography are essential boundary conditions for numerical modelling of the evolution of the Greenland ice-sheet (GrIS). The datasets currently in use by the majority of Greenland ice-sheet modelling studies are over two decades old and based on data collected from the 1970s and 80s. We use a newer, high-resolution Digital Elevation Model of the GrIS and new temperature and precipitation forcings to drive the Glimmer ice-sheet model offline under steady state, present day climatic conditions. Comparisons are made in terms of ice-sheet geometry between these new datasets and older ones used in the EISMINT-3 exercise. We find that changing to the newer bedrock and ice thickness makes the greatest difference to Greenland ice volume and ice surface extent. When all boundary conditions and forcings are simultaneously changed to the newer datasets the ice-sheet is 25% larger in volume compared with observation and 11% larger than that modelled by EISMINT-3. We performed a tuning exercise to improve the modelled present day ice-sheet. Several solutions were chosen in order to represent improvement in different aspects of the Greenland ice-sheet geometry: ice thickness, ice volume and ice surface extent. We applied these new setups of Glimmer to several future climate scenarios where atmospheric CO2 concentration was elevated to 400, 560 and 1120 ppmv (compared with 280 ppmv in the control) using a fully coupled General Circulation Model. Collapse of the ice-sheet was found to occur between 400 and 560 ppmv, a threshold substantially lower than previously modelled using the standard EISMINT-3 setup. This work highlights the need to assess carefully boundary conditions and forcings required by ice-sheet models and the implications that these can have on predictions of ice-sheet geometry under past and future climate scenarios.
Determination of length, area, and volume changes at Storglaciären, Sweden, from multi-temporal aerial images (1959–1999)
Authors: Koblet T. , Gärtner-Roer I. , Zemp M. , Jansson P. , Thee P. , Haeberli W. , Homlund P.
Published: April 2010

Abstract. Storglaciären, located in the Kebnekaise massif in northern Sweden, has a long history of glaciological research. Early photo documentations date back to the late 19th century. Measurements of front position variations and distributed mass balance have been carried out since 1910 and 1945/46, respectively. In addition to these in-situ measurements, aerial photographs have been taken at decadal intervals since the beginning of the mass balance monitoring program and were used to produce glaciological maps. Inaccuracies in the maps were a challenge to early attempts to derive glacier volume changes and resulted in major differences when compared to the direct glaciological mass balances. In this study, we reanalyzed dia-positives of the original aerial photographs of 1959, -69, -80, -90 and -99 based on consistent photogrammetric processing. From the resulting digital elevation models and orthophotos, changes in length, area, and volume of Storglaciären are computed between the survey years, including an assessment of related errors. Between 1959 and 1999, Storglaciären lost an ice volume of 19×106 m3, which corresponds to a cumulative ice thickness loss of 5.69 m and a mean annual loss of 0.14 m. This ice loss resulted largely from a strong volume loss during the period 1959–1980 and was partly compensated during the period 1980–1999. As a consequence, the glacier shows a strong retreat in the 1960s, a slowing in the 1970s, and pseudo-stationary conditions in the 1980s and 1990s.
A glacier inventory for the western Nyainqentanglha Range and Nam Co Basin, Tibet, and glacier changes 1976–2009
Authors: Bolch T. , Yao T. , Kang S. , Buchroithner M. F. , Scherer D. , Maussion F. , Huintjes E. , Schneider C.
Published: April 2010

Abstract. The western Nyainqentanglha Mountain Range is located in the south-eastern centre of the Tibetan Plateau. Its north-western slope drains into Lake Nam Co. The area is of special interest for glacio-climatological research as this region is influenced by both the continental climate of Central Asia and the Indian Monsoon system, and it is situated at the transition zone between temperate and subcontinental glaciers. A glacier inventory for the whole mountain range was generated for the year ~2000 using automated remote sensing and GIS techniques based on Landsat ETM+ and SRTM3 DEM data. The change analysis is based on data from Hexagon KH-9 and Landsat MSS (year 1976), Metric Camera (year 1984), and Landsat TM/ETM+ (1991, 2001, 2005, 2009). Manual adjustment was especially necessary for the panchromatic Hexagon data and for debris-covered glaciers. The whole mountain range contains about 960 glaciers covering an area of 795.6 ± 22.3 km2 while the ice in the drainage basin of Nam Co covers 198.1 ± 5.6 km2. The median elevation of the glaciers is ~5800 m a with the majority terminating around 5600 m. Five glaciers with debris-covered tongues terminate lower than 5200 m. The glacier area decreased between 1976 and 2001 by about 6 ± 3%, which is less than presented in previous studies based on topographic maps from the 1970s and Landsat data from 2000. Glaciers continued to shrink during the period 2001–2009. No advancing glaciers were detected. Detailed length measurements for five glaciers indicate a retreat of the tongues of around 10 m per year (1976–2009) with higher absolute but lower relative values for the larger glaciers.
The role of glaciers in stream flow from the Nepal Himalaya
Authors: Alford D. , Armstrong R.
Published: April 2010

Abstract. Recent concerns related to the potential impacts of the retreat of Himalayan glaciers on the hydrology of rivers originating in the catchment basins of the Himalaya have been accompanied by few analyses describing the role of glaciers in the hydrologic regime of these mountains. This is, at least in part, a result of the relative inaccessibility of the glaciers of the Himalaya, at altitudes generally between 4000–7000 m, and the extreme logistical difficulties of: 1) reaching the glaciers, and 2) conducting meaningful research once they have been reached. It is apparent that an alternative to traditional "Alpine" glaciology is required in the mountains of the Hindu Kush-Himalaya region. The objectives of the study discussed here have been to develop methodologies that will begin to quantify the role of complete glacier systems in the hydrologic regime of the Nepal Himalaya, and to develop estimates of the potential impact of a continued retreat of these glacier, based on the use of disaggregated low-altitude data bases, topography derived from satellite imagery, and simple process models of water and energy exchange in mountain regions. While the extent of mesoscale variability has not been established by studies to date, it is clear that the dominant control on the hydrologic regime of the tributaries to the Ganges Basin from the eastern Himalaya is the interaction between the summer monsoon and the 8000 m of topographic relief represented by the Himalayan wall. All the available evidence indicates that the gradient of specific runoff with altitude resulting from this interaction is moderately to strongly curvilinear, with maximum runoff occurring at mid-altitudes, and minima at the altitudinal extremes. At the upper minimum of this gradient, Himalayan glaciers exist in what has been characterized as an "arctic desert". The methodologies developed for this study involve the relationship between area-altitude distributions of catchment basins and glaciers, based on Shuttle Radar Topography Mission (SRTM3) data and water and energy exchange gradients. Based on these methodologies, it is estimated that the contribution of glacier annual melt water to annual stream flow into the Ganges Basin from the glacierized catchments of the Nepal Himalaya represents approximately 4% of the total annual stream flow volume of the rivers of Nepal, and thus, is a minor component of the annual flow of the Ganges River. The models developed for this study indicate that neither stream flow timing nor volume of the rivers flowing into the Ganges Basin from Nepal will be affected materially by a continued retreat of the glaciers of the Nepal Himalaya.
Climate of the Greenland ice sheet using a high-resolution climate model – Part 2: Near-surface climate and energy balance
Authors: Ettema J. , van den Broeke M. R. , van Meijgaard E. , van de Berg W. J.
Published: April 2010

Abstract. The near-surface climate of the Greenland ice sheet is characterized by persistent katabatic winds and quasi-permanent temperature deficit. Using a high resolution (11 km) regional climate model allows for detailed study of the spatial variability in these phenomena and the underlying atmospheric processes. The near-surface temperature distribution over the ice sheet is clearly affected by elevation, latitude, large scale advection, meso-scale topographic features and the occurrence of summer melt. The lowest annual temperatures of −30.5 °C are found north of the highest elevations of the GrIS, whereas the lowest southern margins are warmest (−3.5 °C). Over the ice sheet, a persistent katabatic wind system develops due to radiative surface cooling and the gently slope of the surface. The strongest wind speeds are seen in the northeast where the strong large scale winds, low cloud cover and concave surface force a continuous supply of cold air, which enhances the katabatic forcing. The radiative cooling of the surface is controlled by the net longwave emission and transport of heat towards the surface by turbulence. In summer this mechanism is much weaker, leading to less horizontal variability in near-surface temperatures and wind speed.
Golimumab reduces sleep disturbance in patients with active ankylosing spondylitis: Results from a randomized, placebo‐controlled trial
Authors: Deodhar Atul , Braun Jürgen , Inman Robert D. , Mack Michael , Parasuraman Shreekant , Buchanan Jacqueline , Hsu Benjamin , Gathany Tim , van der Heijde Désirée
Published: April 2010

Objective

To evaluate the effect of golimumab on sleep disturbance in patients with active ankylosing spondylitis (AS).

Methods

Golimumab was studied in a multicenter, randomized, placebo‐controlled study (GO‐RAISE). At baseline, 356 patients were randomly assigned in a 1.8:1.8:1 ratio to subcutaneous golimumab 50 mg, 100 mg, or placebo every 4 weeks. Sleep disturbance was assessed using the Jenkins Sleep Evaluation Questionnaire (JSEQ), which was administered at baseline, week 14, and week 24. Treatment effect was evaluated using analysis of variance on the van der Waerden normal scores.

Results

Median JSEQ scores at baseline were 9.0 in the placebo group, 10.0 in the 50‐mg group, and 11.0 in the 100‐mg group, indicating moderate to severe sleep disturbance. Patients who received golimumab showed significantly greater median improvement from baseline in JSEQ scores compared with placebo at week 14 (−3.0 versus 0.0; P < 0.001) and week 24 (−3.0 versus −1.0; P < 0.001). Changes from baseline in JSEQ scores significantly correlated with changes from baseline in Short Form 36 summary scores, Bath AS Functional Index scores, total back pain, night back pain, and Bath AS Disease Activity Index scores. Multiple regression analyses indicated that improvement in the night back pain score was the most consistent predictor of change in JSEQ score or reduction in sleep disturbance.

Conclusion

Patients with active AS showed significant sleep disturbance at baseline due to underlying pain associated with AS. Treatment with subcutaneous golimumab every 4 weeks significantly reduced sleep disturbance and improved health‐related quality of life.
Influences of the Process Chain on the Fatigue Behavior of Samples with Tension Screw Geometry
Authors: Klein Marcus , Eifler Dietmar
Published: April 2010

To analyze the influence of the material batch, the structure of the manufacturing process chain, and the process parameters, four different material batches of the quenched and tempered steel SAE 4140 were used to manufacture samples with tension screw geometry. Five different, manufacturing process chains, consisting of the process steps heat treatment, turning, and grinding, were applied. After selected process steps, light and SEM micrographs as well as fatigue experiments were performed. The process itself as well as the process parameters influences the properties of the surface layers and the fatigue behavior in a characteristic manner. For example the variation of the feed rate and cutting speed in the hard‐turning process leads to significantly different mechanical properties of the surface layers and residual stress states, which could be correlated with the fatigue behavior. The cyclic deformation behavior of the investigated components can be benchmarked equivalently with stress–strain hysteresis as well as high precision temperature and electrical resistance measurements. The temperature and electrical resistance measurements are suitable for component applications and provide an enormous advantage of information about the fatigue behavior. The temperature changes of the failed areas of the samples with tension screw geometry were significantly higher, a reliable identification of endangered areas is thereby possible. A new test procedure, developed at the Institute of Materials Science and Engineering of the University of Kaiserslautern, with inserted load‐free‐states during constant amplitude loading, provides the opportunity to detect proceeding fatigue damage in components during inspections.
Control of Solid‐State Dye‐Sensitized Solar Cell Performance by Block‐Copolymer‐Directed TiO2 Synthesis
Authors: Docampo Pablo , Guldin Stefan , Stefik Morgan , Tiwana Priti , Orilall M. Christopher , Hüttner Sven , Sai Hiroaki , Wiesner Ulrich , Steiner Ulrich , Snaith Henry J.
Published: April 2010

Hybrid dye‐sensitized solar cells are typically composed of mesoporous titania (TiO2), light‐harvesting dyes, and organic molecular hole‐transporters. Correctly matching the electronic properties of the materials is critical to ensure efficient device operation. In this study, TiO2 is synthesized in a well‐defined morphological confinement that arises from the self‐assembly of a diblock copolymer—poly(isoprene‐b‐ethylene oxide) (PI‐b‐PEO). The crystallization environment, tuned by the inorganic (TiO2 mass) to organic (polymer) ratio, is shown to be a decisive factor in determining the distribution of sub‐bandgap electronic states and the associated electronic function in solid‐state dye‐sensitized solar cells. Interestingly, the tuning of the sub‐bandgap states does not appear to strongly influence the charge transport and recombination in the devices. However, increasing the depth and breadth of the density of sub‐bandgap states correlates well with an increase in photocurrent generation, suggesting that a high density of these sub‐bandgap states is critical for efficient photo‐induced electron transfer and charge separation.
Fabrication, Optical Modeling, and Color Characterization of Semitransparent Bulk‐Heterojunction Organic Solar Cells in an Inverted Structure
Authors: Ameri Tayebeh , Dennler Gilles , Waldauf Christoph , Azimi Hamed , Seemann Andrea , Forberich Karen , Hauch Jens , Scharber Markus , Hingerl Kurt , Brabec Christoph J.
Published: April 2010

Semitransparent inverted organic photodiodes are fabricated with a Baytron PH500 ethylene‐glycol layer/silver grid as the top electrode. Reasonable performances are obtained under both rear‐ and front‐side illumination and efficiencies up to 2% are achieved. Some light is shed on visual prospects through optical simulations for a semitransparent device of poly(3‐hexylthiophene) (P3HT) and the C60 derivative 1‐(3‐methoxycarbonyl)propyl‐1‐phenyl[6,6]C71 (PC70BM) in the inverted structure. These calculations allow the maximum efficiency achievable to be predicted for semitransparent cells based on P3HT:PC70BM versus the transparency perception for a human eye. The simulations suggest that low‐bandgap materials such as poly[2,6‐(4,4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7‐(2,1,3‐benzothiadiazole)] (PCPDTBT) have a better potential for semitransparent devices. In addition, the color range recognized by the human eye is predicted by the optical simulation for some semitransparent devices including different active layers.
Analysis of von Willebrand factor structure by multimer analysis
Authors: Ledford‐Kraemer Marlies R.
Published: April 2010

Analysis of von Willebrand factor (VWF) structure is achieved by performing a highly specialized procedure, VWF multimer analysis. The test is reserved for the reference or specialized laboratory environment. The assay is qualitative (though under some circumstances multimers may be quantified) in that it assesses the overall size distribution of VWF multimers as well as their individual internal structure. The test is used predominantly to type or subtype von Willebrand disease. The analysis of VWF multimers generally consists of four steps: (1) electrophoresis of plasma in an agarose gel, (2) either gel fixation or transfer of the electrophoretic protein product to a membrane, (3) immunodetection of the protein, and (4) evaluation of the protein in the gel or membrane. The assay is complex, time consuming, requires specialized equipment and technical expertise, and is not standardized. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
Factors associated with safe patient handling behaviors among critical care nurses
Authors: Lee Soo‐Jeong , Faucett Julia , Gillen Marion , Krause Niklas , Landry Lynette
Published: April 2010

Background

Patient handling is a major risk factor for musculoskeletal (MS) injury among nurses. The aims of the study were to describe nurses' work behaviors related to safe patient handling and identify factors influencing their safe work behaviors, including the use of lifting equipment.

Methods

A cross‐sectional study using a mailed questionnaire with a nationwide random sample of 361 critical care nurses. Nurses reported on the physical, psychosocial, and organizational characteristics of their jobs and on their MS symptoms, risk perception, work behaviors, and demographics. Hierarchical multiple linear regression analyses were used to identify significant factors.

Results

More than half of participants had no lifting equipment on their unit, and 74% reported that they performed all patient lift or transfer tasks manually. Significant factors for safer work behavior included better safety climate, higher effort–reward imbalance, less overcommitment, greater social support, and day shift work. Physical workload, personal risk perception, or MS symptom experiences were not associated with safe work behavior.

Conclusions

Safe work behaviors are best understood as socio‐cultural phenomena influenced by organizational, psychosocial, and job factors but, counter to extant theories of health behaviors, do not appear to be related to personal risk perception. Management efforts to improve working conditions and enhance safety culture in hospitals could prove to be crucial in promoting nurses' safe work behavior and reducing risk of MS injury. Am. J. Ind. Med. 53:886–897, 2010. © 2010 Wiley‐Liss, Inc.
Use of O*NET as a job exposure matrix: A literature review
Authors: Cifuentes Manuel , Boyer Jon , Lombardi David A. , Punnett Laura
Published: April 2010

Background

O*NET is a publicly available online database that describes occupational features across US job titles and that has been used to estimate workplace physical and psychosocial exposures and organizational characteristics. The aim of this review is to describe and evaluate the use of O*NET as a job exposure matrix.

Methods

A review of the peer‐reviewed published and gray literature was conducted. Twenty‐eight studies were found that used O*NET to estimate work exposures related to health or safety outcomes. Each was systematically evaluated across eight main features.

Results

Many health outcomes have been studied with O*NET estimates of job exposures. Some studies did not use conceptual definitions of exposure; few studies estimated convergent validity, most used predictive validity. Multilevel analysis was underutilized.

Conclusion

O*NET is worthy of exploration by the occupational health community, although its scientific value is still undetermined. More studies could eventually provide evidence of convergent validity. O*NET has the potential to allow examination of occupational risks that might have otherwise been ignored due to missing data or resource constraints on field data collection of job exposure information. Am. J. Ind. Med. 53:898–914, 2010. © 2010 Wiley‐Liss, Inc.
Work‐related fatalities among youth ages 11–17 in North Carolina, 1990–2008
Authors: Rauscher Kimberly J. , Runyan Carol W. , Radisch Deborah
Published: April 2010

Background

Local and national surveillance systems are in place that identify occupational deaths. However, due to certain restrictions, they are limited in their ability to accurately count these deaths among adolescent workers.

Methods

In this population‐based study, we relied on primary data from the North Carolina medical examiner system to identify and describe all work‐related fatalities among North Carolina youth under age 18 between 1990 and 2008.

Results

We identified 31 work‐related deaths among youth ages 11–17. The majority occurred between 1990 and 1999. Most occurred in construction and agriculture. Vehicles and guns were responsible for the majority of deaths.

Conclusions

Although the prevalence of adolescent work‐related fatalities has seen a decline in North Carolina, the 31 deaths we detected signal a failure of the systems in place to prevent young worker fatalities. More remains to be done to protect the lives of adolescent workers. Am. J. Ind. Med. 54:136–142, 2011. © 2010 Wiley‐Liss, Inc.
Technical note: Terahertz imaging of ancient mummies and bone
Authors: Öhrström Lena , Bitzer Andreas , Walther Markus , Rühli Frank Jakobus
Published: April 2010

Ancient mummified soft‐tissues are a unique source to study the evolution of disease. Diagnostic imaging of such historic tissues is of foremost interest in paleoanthropology or paleopathology, with conventional x‐ray and computed tomography (CT) being the gold‐standard. Longer wavelength radiation in the far‐infrared or Terahertz region allows diagnostic close‐to‐surface tissue differentiation of bone morphology while being harmless to human cells. The aim of this study is to show the feasibility and the morpho‐diagnostic impact of THz imaging of historic remains. Images of an artificially embalmed ancient Egyptian human mummy hand, an artificially embalmed ancient Egyptian mummified fish and a macerated human lumbar vertebra were obtained by THz‐pulse imaging and compared with conventional X‐ray and CT images. Although conventional x‐ray imaging provides higher spatial resolution, we found that THz‐imaging is well‐suited for the investigation of ancient mummified soft tissue and embalming‐related substances / wrappings. In particular, bone and cartilaginous structures can be well differentiated from surrounding soft‐tissues and bandage‐wrappings by THz imaging. Furthermore, THz‐pulse imaging also measures the time‐delay of the pulsed signal when passing through the sample, which provides supplementary information on the optical density of the sample that is not obtained by X‐ray and CT. Terahertz radiation provides a completely non‐invasive diagnostic imaging modality for historic dry specimens. We anticipate this modality also to be used for detection of hidden objects in historic samples such as funerary amulets still in situ in wrapped mummies, as well as potentially for the identification of spectral signatures from chemical substances, e.g., in embalming essences.. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
Worldwide allele frequencies of the human apolipoprotein E gene: Climate, local adaptations, and evolutionary history
Authors: Eisenberg Dan T.A. , Kuzawa Christopher W. , Hayes M. Geoffrey
Published: April 2010

The ϵ4 allele of the apolipoprotein E (APOE) gene is associated with increased cholesterol levels and heart disease. Population allele frequencies of APOE have previously been shown to vary, with ϵ4 frequencies generally increasing with latitude. We hypothesize that this trend resulted from natural selection protecting against low‐cholesterol levels. In high‐latitude cold environments and low‐latitude hot environments, metabolic rate is elevated, which could require higher cholesterol levels. To explore this hypothesis, we compiled APOE allele frequencies, latitude, temperature, and elevation from populations around the world. ϵ4 allele frequencies show a curvilinear relationship with absolute latitude, with lowest frequencies found in the mid‐latitudes where temperatures generally require less expenditure on cooling/thermogenesis. Controlling for population structure in a subset of populations did not appreciably change this pattern of association, consistent with selection pressures that vary by latitude shaping ϵ4 allele frequencies. Temperature records also predict APOE frequency in a curvilinear fashion, with lowest ϵ4 frequencies at moderate temperatures. The model fit between historical temperatures and ϵ4 is less than between latitude and ϵ4, but strengthened after correcting for estimated temperature differences during the Paleolithic. Contrary to our hypothesis, we find that elevation did not improve predictive power, and an integrated measure of the cholesterol effect of multiple APOE alleles was less related to latitude than was ϵ4 alone. Our results lend mixed support for a link between past temperature and human APOE allele distribution and point to the need to develop better models of past climate in future analyses. Am J Phys Anthropol 143:13–20, 2010. © 2010 Wiley‐Liss, Inc.
Monkeys and apes: Are their cognitive skills really so different?
Authors: Amici Federica , Aureli Filippo , Call Josep
Published: April 2010

Differences in cognitive skills across taxa, and between monkeys and apes in particular, have been explained by different hypotheses, although these often are not supported by systematic interspecific comparisons. Here, we directly compared the cognitive performance of the four great apes and three monkey species (spider monkeys, capuchin monkeys, and long‐tailed macaques), differing in their phylogenetic‐relatedness and socioecology. We tested subjects on their ability to remember object locations (memory task), track object displacements (transposition task), and obtain out‐of‐reach rewards (support task). Our results showed no support for an overall clear‐cut distinction in cognitive skills between monkeys and apes as species performance varied substantially across tasks. Although we found differences in performance at tracking object displacements between monkeys and apes, interspecific differences in the other two tasks were better explained in terms of differential socioecology, especially differential levels of fission–fusion dynamics. A cluster analysis using mean scores of each condition of the three tasks for each species suggested that the only dichotomy might be between members of the genusPanand the rest of the tested species. These findings evidence the importance of using multiple tasks across multiple species in a comparative perspective to test different explanations for the enhancement of specific cognitive skills. Am J Phys Anthropol 143:188–197, 2010. © 2010 Wiley‐Liss, Inc.
Articular to diaphyseal proportions of human and great ape metatarsals
Authors: Marchi Damiano
Published: April 2010

This study proposes a new way to use metatarsals to identify locomotor behavior of fossil hominins. Metatarsal head articular dimensions and diaphyseal strength in a sample of chimpanzees, gorillas, orangutans, and humans (n= 76) are used to explore the relationships of these parameters with different locomotor modes. Results show that ratios between metatarsal head articular proportions and diaphyseal strength of the hallucal and fifth metatarsal discriminate among extant great apes and humans based on their different locomotor modes. In particular, the hallucal and fifth metatarsal characteristics of humans are functionally related to the different ranges of motion and load patterns during stance phase in the forefoot of humans in bipedal locomotion. This method may be applicable to isolated fossil hominin metatarsals to provide new information relevant to debates regarding the evolution of human bipedal locomotion. The second to fourth metatarsals are not useful in distinguishing among hominoids. Further studies should concentrate on measuring other important qualitative and quantitative differences in the shape of the metatarsal head of hominoids that are not reflected in simple geometric reconstructions of the articulation, and gathering more forefoot kinematic data on great apes to better understand differences in range of motion and loading patterns of the metatarsals. Am J Phys Anthropol 143:198–207, 2010. © 2010 Wiley‐Liss, Inc.
The locust foraging gene
Authors: Lucas C. , Kornfein R. , Chakaborty‐Chatterjee M. , Schonfeld J. , Geva N. , Sokolowski M. B. , Ayali A.
Published: April 2010

Our knowledge of how genes act on the nervous system in response to the environment to generate behavioral plasticity is limited. A number of recent advancements in this area concern food‐related behaviors and a specific gene family called foraging (for), which encodes a cGMP‐dependent protein kinase (PKG). The desert locust (Schistocerca gregaria) is notorious for its destructive feeding and long‐term migratory behavior. Locust phase polyphenism is an extreme example of environmentally induced behavioral plasticity. In response to changes in population density, locusts dramatically alter their behavior, from solitary and relatively sedentary behavior to active aggregation and swarming. Very little is known about the molecular and genetic basis of this striking behavioral phenomenon. Here we initiated studies into the locust for gene by identifying, cloning, and studying expression of the gene in the locust brain. We determined the phylogenetic relationships between the locust PKG and other known PKG proteins in insects. FOR expression was found to be confined to neurons of the anterior midline of the brain, the pars intercerebralis. Our results suggest that differences in PKG enzyme activity are correlated to well‐established phase‐related behavioral differences. These results lay the groundwork for functional studies of the locust for gene and its possible relations to locust phase polyphenism. © 2010 Wiley Periodicals, Inc.
Genetic variation in the SMAD3 gene is associated with hip and knee osteoarthritis
Authors: Valdes Ana M. , Spector Tim D. , Tamm Agu , Kisand Kalle , Doherty Sally A. , Dennison Elaine M. , Mangino Massimo , Tamm Ann , Kerna Irina , Hart Deborah J. , Wheeler Margaret , Cooper Cyrus , Lories Rik J. , Arden Nigel K. , Doherty Michael
Published: April 2010

Objective

Smad3 (or, MADH3) is a key intracellular messenger in the transforming growth factor β signaling pathway. In mice, Smad3 deficiency accelerates growth plate chondrocyte maturation and leads to an osteoarthritis (OA)–like disease. We undertook this study to investigate the role of genetic variation in SMAD3 in the risk of large‐joint OA in humans.

Methods

Ten tag single‐nucleotide polymorphisms (SNPs) in the SMAD3 gene region were tested in a discovery set: 313 patients who had undergone total knee replacement, 214 patients who had undergone total hip replacement, and 520 controls from the UK. The SNP associated with both hip and knee OA was subsequently genotyped in 1,221 controls and 1,074 cases from 2 cohorts of patients with hip OA and 2,537 controls and 1,575 cases from 4 cohorts of patients with knee OA.

Results

A SNP (rs12901499) mapping to intron 1 of SMAD3 was associated with both knee and hip OA (P < 0.0022 and P < 0.021, respectively) in the discovery set. In all study cohorts, the major allele (G) was increased among OA patients relative to controls. A meta‐analysis for knee OA yielded an odds ratio (OR) of 1.22 (95% confidence interval [95% CI] 1.12–1.34), P < 7.5 × 10−6. For hip OA, the OR was 1.22 (95% CI 1.09–1.36), P < 4.0 × 10–4. No evidence for heterogeneity was found (I2 = 0%).

Conclusion

Our data indicate that genetic variation in the SMAD3 gene is involved in the risk of both hip OA and knee OA in European populations, confirming the results from animal models on the potential importance of this molecule in the pathogenesis of OA.
Über die gleichzeitige Abscheidung von Eisen und Nickel aus den gemischten Lösungen der Sulfate
Authors: W. Küster F.
Published: April 2010

No Abstracts.
Stimulation of the HIV‐1 integrase enzymatic activity and cDNA integration by a peptide derived from the integrase protein
Authors: Levin Aviad , Hayouka Zvi , Helfer Markus , Brack‐Werner Ruth , Friedler Assaf , Loyter Abraham
Published: April 2010

Here we describe the features of a peptide that was selected from the human immunodeficiency virus Type 1 (HIV‐1) Integrase (IN) peptide library which interacts with both, the viral Rev and IN proteins. Because of its ability to stimulate the IN enzymatic activity this peptide was designated INS (IN stimulatory). Modification of its amino acid sequence revealed that replacement of its C‐terminal lysine by glutamic acid (INS K188E) converts it from a stimulatory peptide to an inhibitory one. Both peptides promoted the dissociation of a previously described complex formed between Rev and IN whose formation results in IN inactivation. INS and INS K188E penetrated HIV‐1‐infected cells and caused stimulation and inhibition of viral genome integration, respectively. Using cultured cells infected with a ΔRev HIV revealed that INS can directly activate the viral IN. These results suggest that the stimulatory effect of INS in wild‐type virus‐infected cells is due to a dual effect: it dissociates the inactive Rev‐IN complex and directly activates the free IN. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 740–751, 2010.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Behavioral genetics in antisocial spectrum disorders and psychopathy: A review of the recent literature
Authors: Gunter Tracy D. , Vaughn Michael G. , Philibert Robert A.
Published: April 2010

Behavioral geneticists are increasingly using the tools of molecular genetics to extend upon discoveries from twin, family, and adoption studies concerning the heritability of antisocial spectrum disorders and psychopathy. While there is a substantial body of research concerning antisocial spectrum disorders in the behavioral genetics literature, only a few studies could be located using the phenotype of psychopathy. In this report we summarize some of the recent molecular genetics work concerning antisocial spectrum disorders and psychopathy, with a focus on genes involved in the serotonergic and dopaminergic pathways, while also mentioning some of the novel genetic factors being considered. Monoamine oxidase (MAOA) and the serotonin transporter (5HTT) are reviewed at length, as these genes have received significant scientific attention in recent years and are sites of high biological plausibility in antisocial spectrum disorders and psychopathy. Copyright © 2010 John Wiley & Sons, Ltd.
Treatment of psychopathy: A review and brief introduction to the mental model mpproach for psychopathy
Authors: Salekin Randall T. , Worley Courtney , Grimes Ross D.
Published: April 2010

Psychopathy is thought by many to be an untreatable disorder. This article puts the treatment of psychopathy into historical context and reviews research on the treatment of the disorder with adults (K = 8) and youth (K = 5). Findings indicate that treatment for adults shows low to moderate success with three of eight studies demonstrating treatment gains. Treatment of youth appears to be more promising with six of eight studies showing treatment benefits. Although less than optimal success rates with adults, we suggest that bright line distinctions regarding the treatability of those with psychopathic characteristics from non‐psychopathic individuals are inappropriate at this time. We conclude with directions for future research and briefly introduce the mental models approach for the treatment of psychopathy in youths. Copyright © 2010 John Wiley & Sons, Ltd.
Use of XFOIL in design of camber‐controlled morphing UAVs
Authors: Lafountain Cody , Cohen Kelly , Abdallah Shaaban
Published: April 2010

The standard curriculum for Aerospace Engineering students at the University of Cincinnati includes AEEM361 Integrated Aircraft Engineering. The goal of this course is to instruct students in the tools and methodology of aircraft design. The integrated aspects of aircraft design are underscored by introducing pre‐junior (between sophomore and junior) students to the state‐of‐the‐art morphing technology, inspired by bat and bird flight, which can enable an aircraft to adapt its shape to best suit the flight condition thereby enhancing mission performance. In this article, we present the development of unique software tools, which provide undergraduates an opportunity to design airfoils for morphing aircraft. Morphing is introduced in the form of “on demand” camber as well as sweep change with the aim of improving aerodynamic efficiency for a multi‐objective (several design points) mission profile. The Global Hawk UAV mission in general and its LRN1015 airfoil in particular is in focus due to the relative long mission times spent at the two different flight conditions, namely high‐speed dash and low‐speed loiter. We are using several tools to virtually simulate a morphing wing including XFOIL to perform fast and relatively accurate two‐dimensional steady‐flow simulations of different morphed configurations using a camber‐controlled morphed wing to maneuver. In this article we detail AeroMorph, the educational MATLAB‐based tool developed for design of a camber‐controlled morphing of airfoils with the aim of improving aerodynamic efficiency and exploration of the basic relationships between flap deflection and airfoil morphing based on a camber change. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 673–680, 2012
Development of a New Generation of Gold Catalysts for Amine Oxidation
Authors: Aschwanden Linda , Mallat Tamas , Maciejewski Marek , Krumeich Frank , Baiker Alfons
Published: April 2010

A new type of outstandingly active gold catalysts has been developed for the aerobic oxidation of amines to imines. The gold nanoparticles are generated in situ in an organic medium prior to the oxidation reaction. Various gold salts, preferably AuCl3 and HAuCl4⋅3 H2O, can be applied in the presence of nanoceria and the amine substrate acts as the reducing agent. The synergism between gold and ceria evacuated at 200 °C has a remarkable positive effect on the oxidation activity. The catalysts have been tested in the oxidation of dibenzylamine, N‐tert‐butylbenzylamine, and indoline. Apparently, the presence of organic and inorganic residue after the in situ catalyst preparation does not diminish the oxidation activity of gold. An alternative, less efficient route is the quantitative adsorption of [Au(PPh3)Cl] precursor onto ceria in an organic medium and the subsequent ex situ evolution of gold nanoparticles (ca. 5 nm) via calcination at 250–400 °C. This catalyst is still tenfold more active than conventional supported gold nanoparticles. In addition, it is free from impurities evolving during the in situ preparation and thus may find application in reactions other than amine oxidation.