bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling time to event with observations made at arbitrary times
Authors: Sperrin Matthew , Buchan Iain
Published: July 2012

In many time‐to‐event studies, particularly in epidemiology, the time of the first observation or study entry is arbitrary in the sense that this is not a time of risk modification. We present a formal argument that, in these situations, it is not advisable to take the first observation as the time origin, either in accelerated failure time or proportional hazards models. Instead, we advocate using birth as the time origin. We use a two‐stage process to account for the fact that baseline observations may be made at different ages in different subjects. First, we marginally regress any potentially age‐varying covariates against age, retaining the residuals. These residuals are then used as covariates in fitting an accelerated failure time or proportional hazards model — we call the procedures residual accelerated failure time regression and residual proportional hazards regression, respectively. We compare residual accelerated failure time regression with the standard approach, demonstrating superior predictive ability of the residual method in realistic examples and potentially higher power of the residual method. This highlights flaws in current approaches to communicating risks from epidemiological evidence to support clinical and health policy decisions. Copyright © 2012 John Wiley & Sons, Ltd.
Microarray with Micro‐ and Nano‐topographies Enables Identification of the Optimal Topography for Directing the Differentiation of Primary Murine Neural Progenitor Cells
Authors: Moe Aung Aung Kywe , Suryana Mona , Marcy Guillaume , Lim Sandy Keat , Ankam Soneela , Goh Jerome Zhi Wen , Jin Jing , Teo Benjamin Kim Kiat , Law Jaslyn Bee Khuan , Low Hong Yee , Goh Eyleen L. K. , Sheetz Michael P. , Yim Evelyn K. F.
Published: July 2012

During development and tissue repair, progenitor cells are guided by both biochemical and biophysical cues of their microenvironment, including topographical signals. The topographical cues have been shown to play an important role in controlling the fate of cells. Systematic investigation of topographical structures with different geometries and sizes under the identical experimental conditions on the same chip will enhance the understanding of the role of shape and size in cell–topography interactions. A simple customizable multi‐architecture chip (MARC) array is therefore developed to incorporate, on a single chip, distinct topographies of various architectural complexities, including both isotropic and anisotropic features, in nano‐ to micrometer dimensions, with different aspect ratios and hierarchical structures. Polydimethylsiloxane (PDMS) replicas of MARC are used to investigate the influence of different geometries and sizes in neural differentiation of primary murine neural progenitor cells (mNPCs). Anisotropic gratings (2 μm gratings, 250 nm gratings) and isotropic 1 μm pillars significantly promote differentiation of mNPCs into neurons, as indicated by expression of β‐III‐tubulin (59%, 58%, and 58%, respectively, compared to 30% on the control). In contrast, glial differentiation is enhanced on isotropic 2 μm holes and 1 μm pillars. These results illustrate that anisotropic topographies enhance neuronal differentiation while isotropic topographies enhance glial differentiation on the same chip under the same conditions. MARC enables simultaneous cost‐effective investigation of multiple topographies, allowing efficient optimization of topographical and biochemical cues to modulate cell differentiation.
Effectiveness of WRF wind direction for retrieving coastal sea surface wind from synthetic aperture radar
Authors: Takeyama Yuko , Ohsawa Teruo , Kozai Katsutoshi , Hasager Charlotte Bay , Badger Merete
Published: July 2012

Wind direction is required as input to the geophysical model function (GMF) for the retrieval of sea surface wind speed from a synthetic aperture radar (SAR) images. The present study verifies the effectiveness of using the wind direction obtained from the weather research and forecasting model (WMF) as input to the GMF to retrieve accurate wind fields in coastal waters adjacent to complex onshore terrain. The wind speeds retrieved from 42 ENVISAT ASAR images are validated based on in situ measurements at an offshore platform in Japan. Accuracies are also compared with cases using wind directions: the meso‐analysis of the Japan Meteorological Agency (MANAL), the SeaWinds microwave scatterometer on QuikSCAT and the National Center for Environmental Prediction final operational global analysis data (NCEP FNL).

In comparison with the errors of the SAR‐retrieved wind speeds obtained using the WRF, MANAL, QuikSCAT and NCEP FNL wind directions, the magnitudes of the errors do not appear to be correlated with the errors of the wind directions themselves. In addition to wind direction, terrain factors are considered to be a main source of error other than wind direction. Focusing on onshore winds (blowing from the sea to land), the root mean square errors on wind speed are found to be 0.75 m s  − 1 (in situ), 0.96 m s  − 1 (WRF), 1.75 m s  − 1 (MANAL), 1.58 m s  − 1 (QuikSCAT) and 2.00 m s  − 1 (NCEP FNL), respectively, but the uncertainty is of the same order of magnitude because of the low number of cases. These results indicate that although the effectiveness of using the accurate WRF wind direction for the wind retrieval is partly confirmed, further efforts to remove the error due to factors other than wind direction are necessary for more accurate wind retrieval in coastal waters. Copyright © 2012 John Wiley & Sons, Ltd.
Trading wind energy on the basis of probabilistic forecasts both of wind generation and of market quantities
Authors: Zugno M. , Jónsson T. , Pinson P.
Published: July 2012

Wind power is not easily predictable and non‐dispatchable. Nevertheless, wind power producers are increasingly urged to participate in electricity market auctions in the same manner as conventional power producers. The aim of this paper is to propose an operational strategy for trading wind energy in liberalized electricity markets and to assess its performance. At first, the so‐called optimal quantile strategy is revisited. It is proved that without market power, i.e. under the price‐taker assumption, this strategy maximizes expected market revenues. Forecasts of wind power production, of day‐ahead and real‐time market prices and of the system imbalance are inputs to this strategy. Subsequently, constraining of the bid that maximizes the expected revenues is proposed as a way to overcome the strategy's disregard of practical limitations and, at the same time, of risk. Two constraining techniques are introduced: constraining in the decision space and in the probability space. Finally, the trade of a wind power producer is simulated in a test case for the Eastern Danish (DK‐2) price area of the Nordic Power Exchange (Nord Pool) during a 10 month period in 2008. The results of the test case show the financial benefits of the aforementioned strategy as well as the consequent interaction with the electricity market. This study will support a demonstration in the framework of the EU project ANEMOS.plus. Copyright © 2012 John Wiley & Sons, Ltd.
Multi‐body modelling and analysis of a planet carrier in a wind turbine gearbox
Authors: Xing Y. , Moan T.
Published: July 2012

There have been some recent efforts to numerically model and analyse the wind turbine gearbox. To date, much of the focus has been on increasing model refinement and demonstrating its added value. This paper takes a step back and examines in detail the modelling and analysis of an important wind turbine gearbox component, the planet carrier, in a multi‐body setting. The planet carrier studied in this work comes from the 750 kW wind turbine gearbox used in the National Renewable Energy Laboratory's Gearbox Reliability Collaborative project. The study is performed in two parts. First, the influence of subcomponents mated to the planet carrier in the gearbox assembly is investigated in detail. These components consist of the planet pins, bearings and the main shaft. In the second part of the study, the flexible body modelling of the planet carrier for use in multi‐body simulations is examined through the use of condensed finite element and multi‐body simulation models. Both eigenvalue analyses and time domain simulations are performed. Comparisons are made regarding the eigenfrequencies, categorized mode shapes and the maximum and minimum planet carrier rim deflections from the time domain simulations. The mode shapes are categorized into seven distinct deformation patterns. An actual load case from the dynamometer tests, a 100% rated torque loading, is used in the time domain simulations. The results from this comprehensive study provide an insight into the proper modelling of a wind turbine planet carrier in a multi‐body setting. Copyright © 2012 John Wiley & Sons, Ltd.
Detrital zircon geochronology and sandstone provenance of basement Waipapa Terrane (Triassic–Cretaceous) and Cretaceous cover rocks (Northland Allochthon and Houhora Complex) in northern North Island, New Zealand
Authors: ADAMS C. J. , MORTIMER N. , CAMPBELL H. J. , GRIFFIN W. L.
Published: July 2012

Detrital zircon U–Pb ages are reported for 14 sandstones of mainly Cretaceous age from the Northland Allochthon, Houhora Complex and Waipapa Terrane of northern North Island, New Zealand. Results from the Waipapa Terrane samples, selected from sequences in the Bay of Plenty, Coromandel Peninsula and Great Barrier Island, show that deposition continued into late Early Cretaceous time and, as in the Torlesse Composite Terrane, finally waned at c. 110–114 Ma. Upper Lower Cretaceous and Upper Cretaceous sedimentary successions in the Houhora Complex and Northland Allochthon have dominant sediment sources derived from local, contemporary volcanism, with a minor older contribution from the Murihiku Terrane to the west. As in eastern North Island, upper Upper Cretaceous sandstones lack major Albian magmatic components and their sources are solely in the Murihiku Terrane, and possibly the Western Province. We propose a Cretaceous palaeogeographic model that invokes a recently extinct orogen and a partially submerged continental borderland, dissected by rivers supplying submarine fans.
Enhancing the value of horizon scanning through collaborative review
Authors: Sutherland William J. , Allison Hilary , Aveling Rosalind , Bainbridge Ian P. , Bennun Leon , Bullock David J. , Clements Andy , Crick Humphrey Q. P. , Gibbons David W. , Smith Sarah , Rands Michael R. W. , Rose Paul , Scharlemann Jörn P. W. , Warren Martin S.
Published: July 2012

There is an increased appreciation of the need for horizon scanning: the identification and assessment of issues that could be serious in the future but have currently attracted little attention. However, a process is lacking to identify appropriate responses by policy makers and practitioners. We thus suggest a process and trial its applicability. Twelve environmental conservation organizations assessed each of 15 previously identified horizon scanning issues for their impact upon their organization and the urgency with which they should consider the issue. They also identified triggers that would result in changes in their scoring of the likely urgency and impact of the issues. This process enables organizations to identify priority issues, identify issues they can ignore until there are further developments, benchmark priorities across organizations and identify cross-organizational priorities that warrant further attention, so providing an agenda for collation of evidence, research and policy development. In this trial the review of responses by other organizations resulted in the upgrading of response by a substantial proportion of organizations for eight of the 15 issues examined. We suggest this approach, with the novel components of collaborative assessment and identification of triggers, could be adopted widely, both within conservation organizations and across a wider range of policy issues.
Trading information for conservation: a novel use of radio broadcasting to reduce sea turtle bycatch
Authors: Alfaro-Shigueto Joanna , Mangel Jeffrey C. , Dutton Peter H. , Seminoff Jeffrey A. , Godley Brendan J.
Published: July 2012

Bycatch of non-target animals in small-scale fisheries poses a major threat to seabirds and marine mammals and turtles. This is also a problem for small-scale fisheries in Peru because of the magnitude of these fisheries and the important marine biodiversity in Peruvian waters. Here we describe how we implemented a novel approach to mitigate bycatch impacts on marine turtles in Peru. We used high-frequency (HF) two-way radio communication to exchange information with fishers. We sought data that would afford insights into fishing patterns and levels of turtle bycatch so that we could identify areas of high-density bycatch in real time and warn other fishers. In return we provided oceanographic and atmospheric information useful for the fishers. Radio communication also served as a platform to promote the use of safe handling and release techniques for incidentally caught animals. During the 24 months of the programme we communicated with over 200 vessels and with 200–1,400 fishers, who used primarily longlines, gillnets, jiggers, purse seiners and trawlers. Our findings suggest that HF radio communication is a useful tool (low cost and widely used by fishers, with extensive spatial coverage), helps build links with fishers that potentially reduces fishery impacts on marine turtles, and can also provide information on poorly documented fisheries and the relevant bycatch data associated with small-scale fishing practices.
Social networks and subjective wellbeing among older Europeans: does age make a difference?
Authors: LITWIN HOWARD , STOECKEL KIMBERLY J.
Published: July 2012

This inquiry examined whether social networks are associated with wellbeing among older-old people in the same way that they are among younger-old persons. The study focused on family respondents, aged 60 and older, from the second wave of the Survey of Health, Ageing and Retirement in Europe (N=14,728). The statistical analysis regressed two wellbeing measures (the CASP quality of life scale and life satisfaction) on a range of social network variables from three domains: family structure and interaction, social exchange and social engagement. In addition, the inquiry viewed these associations through the lens of age-based interaction terms, controlling for background characteristics, health status and region. The analysis revealed that the associations between subjective wellbeing and social network vary according to age. Among younger-old respondents, aged 60–79, more significant associations were found between social network variables and wellbeing outcomes in comparison to older-old respondents, aged 80 or older. Differences between age groups also emerged with the direction of the associations between social network variables and subjective wellbeing. The study results reveal that social networks do matter in very old age, but not in the same way as among younger-old persons. This finding is one indication of the differences that may emerge between third-age adults and those approaching the fourth age.
Quantifying the indirect effects of key child survival interventions for pneumonia, diarrhoea, and measles
Authors: WALKER C. L. FISCHER , MUNOS M. K. , BLACK R. E.
Published: July 2012

To date many studies have measured the effect of key child survival interventions on the main cause of mortality while anecdotally reporting effects on all-cause mortality. We conducted a systematic literature review and abstracted cause-specific and all-cause mortality data from included studies. We then estimated the effect of the intervention on the disease of primary interest and calculated the additional deaths prevented (i.e. the indirect effect). We calculated that insecticide-treated nets have been shown to result in a 12% reduction [95% confidence interval (CI) 0·0–23] among non-malaria deaths. We found pneumonia case management to reduce non-pneumonia mortality by 20% (95% CI 8–22). For measles vaccine, seven of the 10 studies reporting an effect on all-cause mortality demonstrated an additional benefit of vaccine on all-cause mortality. These interventions may have benefits on causes of death beyond the specific cause of death they are targeted to prevent and this should be considered when evaluating the effects of implementation of interventions.
Habitat selection of Marbled Teal and White-headed Duck during the breeding and wintering seasons in south-eastern Spain
Authors: SEBASTIÁN-GONZÁLEZ ESTHER , FUENTES CRISTINA , FERRÁNDEZ MARCOS , ECHEVARRÍAS JOSÉ L. , GREEN ANDY J.
Published: July 2012

Understanding habitat requirements is vital for developing successful management strategies for threatened species. In this study we analyse the habitat selection of two globally threatened waterbirds (Marbled TealMarmaronetta angustirostrisand White-headed DuckOxyura leucocephala)coexisting in an internationally important wetland (El Hondo Natural Park, south-eastern Spain) at three spatial scales. We surveyed adults and broods of these species fortnightly during two consecutive years and we related density and presence of birds to several habitat variables. At a pond-selection scale, the density of both species was related to the surface area of the ponds, with Marbled Teal showing avoidance of medium-sized ponds, and White-headed Ducks strong selection for the largest ponds. Within ponds, Marbled Teal avoided open waters, and was mainly associated withPhragmitesreedbeds, but also selected areas with saltmarsh andScirpusvegetation, especially for brood-rearing. White-headed Duck made more use of deeper areas with open water, especially in winter, andPhragmiteswas the only emergent vegetation with which it associated. When breeding success was very high in 2000, strong creching of broods was observed in White-headed Duck, but not in Marbled Teal. In order to provide suitable habitat for both species, there is a need to maintain spatial diversity with a combination of large wetlands suitable for both species and small, vegetated ones suitable for the Marbled Teal.
Origin of the terms embryo, gamete and zygote
Authors: Herranz Gonzalo
Published: July 2012

The scope of this article is to answer two questions: first, when were the terms embryo (E), gamete (G) and zygote (Z) coined, and second, who were the scientists who put them in circulation? In order to clarify and document the origin of these three words, a vast amount of biomedical literature, particularly from the late 19th and early 20th centuries, has been reviewed; an undertaking made possible by the free access to the massive repository of available scientific literature on the Internet. Furthermore, as a result of this analysis, I would like to raise some ethical aspects of scientific publication, in particular the obligation of scientists to personally assess the quality and source of data they take from the literature and use in their publications.
Asylum-Seekers' Experiences of Trauma-Focused Cognitive Behaviour Therapy for Post-Traumatic Stress Disorder: A Qualitative Study
Authors: Vincent Felicity , Jenkins Helen , Larkin Michael , Clohessy Sue
Published: July 2012

Background: Trauma-focused CBT (TFCBT) is an evidence-based treatment for post-traumatic stress disorder (PTSD), but little is known about whether it is an acceptable and effective treatment for asylum-seekers presenting with PTSD. Aims: This study considers the acceptability of TFCBT for asylum-seekers with PTSD by exploring their experiences of this treatment. Method: Seven asylum-seekers who had received CBT involving a TFCBT component were interviewed using a semi-structured schedule. The transcribed interviews were analysed using interpretative phenomenological analysis (IPA). Interpretative themes were developed iteratively to closely reflect participants’ common and distinct experiences. Results: Six super-ordinate interlinking themes are discussed: Staying where you are versus engaging in therapy; Experiences encouraging engagement in therapy; Experiences impeding engagement in therapy; Importance of the therapeutic relationship; “Losing oneself” and “Regaining life”. Conclusions: Participants described their ambivalence about engaging in TFCBT. Such treatment was experienced as very challenging, but most participants also reported finding it helpful. Various experiences that appeared to encourage or impede engagement are outlined. These preliminary findings suggest that fear of repatriation can impede engagement in TFCBT, but that some asylum-seekers with PTSD still report finding TFCBT beneficial. The clinical implications are discussed, including the special importance of the therapeutic relationship.
Humanitarian organizations involved in protection activities: a story of soul-searching and professionalization
Authors: Gentile Pierre
Published: July 2012

In this article, I argue that humanitarian actors are becoming increasingly professional when designing and implementing protection activities in situations of armed conflict and violence. According to my own personal experience, the International Committee of the Red Cross (ICRC) has undergone drastic changes over the last two decades. The institution has diversified the type of protection activities it can implement; it now gives more attention to various population groups and their ability to develop resilience to different types of threat; and, finally, it is increasingly putting more emphasis on the training and career paths of its field delegates working on protection issues. Such changes are not the exclusive trademark of the ICRC. Many humanitarian and human rights actors working on protection issues have undertaken similar adjustments.

The article notes that much clarity on protection concepts, as well as considerable field experience, has been gained since the 1990s. The number of humanitarian and human rights organizations implementing protection activities in the field has steadily increased. Positive as well as negative lessons learned have been documented and have helped to shape institutional guidance and guidelines. Inter-institutional exchanges have strengthened, allowing the development of professional standards for protection work, to ensure that protection work is as safe and efficient as possible. In the end, this professionalization of the field of protection is in the best interests of both the communities affected by violence and disasters, and the humanitarian field workers confronted by complex challenges.
Effect of temperature, pressure and iron content on the electrical conductivity of olivine and its high‐pressure polymorphs
Authors: Yoshino Takashi , Shimojuku Akira , Shan Shuanming , Guo Xinzhuan , Yamazaki Daisuke , Ito Eiji , Higo Yuji , Funakoshi Ken‐ichi
Published: July 2012

The electrical conductivity of olivine and its high‐pressure polymorphs with various iron contents [XFe = Fe/(Fe + Mg) = 0.1, 0.2, 0.3, 0.5, 0.7 and 1.0] was measured over a wide range of pressure (P) and temperature (T) conditions covering the stability field of olivine, wadsleyite and ringwoodite in a Kawai‐type multianvil apparatus. The pressure was determined using in situ X‐ray diffraction of MgO as a pressure marker in SPring 8. Molybdenum electrodes were used so that oxygen fugacity is similar to that for the iron‐wüstite buffer. The transition from low‐pressure phase to high‐pressure phase led to an increase of conductivity. In the stability field of each phase, the electrical conductivity slightly increased with increasing pressure at a constant temperature, suggesting a negative activation volume. The conductivity increased with increasing total iron content for each phase. All electrical conductivity data fit the formula for electrical conductivityσ = σ0 XFeexp{−[ΔE0 − αXFe1/3 + P(ΔV0 − βXFe)]/kT}, where σ0is the pre‐exponential term, ΔE0 and ΔV0 are the activation energy and the activation volume at very low total iron concentration, respectively, and k is the Boltzmann constant. The activation energy decreased with increasing total Fe content in olivine and ringwoodite. Dependence of the activation energy on the total Fe content suggests that the dominant mechanism of charge transport is Fe2+‐Fe3+hopping (small polaron). The activation volume for small polaron conduction in olivine and its high‐pressure polymorphs tends to decrease with total Fe content. For olivine with low Fe content, the activation volume for small polaron conduction still is negative and very small. Assuming constant Fe content (XFe = 0.1) and oxygen buffer condition, the conductivity will increase with depth mainly due to the increase of the temperature along the mantle adiabat.
Low temperature optical constants of some hydrated sulfates relevant to planetary surfaces
Authors: Dalton J. B. , Pitman K. M.
Published: July 2012

We derive optical constants (n(λ) and k(λ)) from laboratory reflectance spectra acquired at visible to near‐infrared wavelengths for epsomite (MgSO4⋅7H2O), bloedite (Na2Mg(SO4)2⋅4H2O), and hexahydrite (MgSO4⋅6H2O) at both room temperature and 120 K. These hydrated sulfates are candidate surface compounds for outer solar system icy satellites such as Europa, Ganymede, and Callisto, as well as Mars. Our results permit quantitative abundance modeling of Galileo, Cassini‐Huygens, New Horizons, Mars Reconnaissance Orbiter, Mars Express, and future mission spacecraft observations leading to better interpretation of these objects' surface and interior geological processes and histories.
Satellite observations of Antarctic sea ice thickness and volume
Authors: Kurtz N. T. , Markus T.
Published: July 2012

We utilize satellite laser altimetry data from NASA's Ice, Cloud, and land Elevation Satellite (ICESat) combined with passive microwave measurements to analyze basin‐wide changes in Antarctic sea ice thickness and volume over a 5 year period from 2003–2008. Sea ice thickness exhibits a small negative trend while area increases in the summer and fall balanced losses in thickness leading to small overall volume changes. Using a 5 year time series, we show that only small ice thickness changes of less than −0.03 m/yr and volume changes of −266 km3/yr and 160 km3/yr occurred for the spring and summer periods, respectively. These results are in stark contrast to the much greater observed losses in Arctic sea ice volume and illustrate the different hemispheric changes of the polar sea ice covers in recent years. The uncertainties in the calculated thickness and volume trends are large compared to the observed basin‐scale trends. This masks the determination of a long‐term trend or cyclical variability in the sea ice cover. It is found that lengthening of the observation time series along with better determination of the interannual variability of sea ice and snow densities will allow for a more statistically significant determination of long‐term sea ice thickness and volume trends in the Southern Ocean.
The summer North Atlantic Oscillation in CMIP3 models and related uncertainties in projected summer drying in Europe
Authors: Bladé Ileana , Fortuny Didac , van Oldenborgh Geert Jan , Liebmann Brant
Published: July 2012

This paper discusses uncertainties in model projections of summer drying in the Euro‐Mediterranean region related to errors and uncertainties in the simulation of the summer NAO (SNAO). The SNAO is the leading mode of summer SLP variability in the North Atlantic/European sector and modulates precipitation not only in the vicinity of the SLP dipole (northwest Europe) but also in the Mediterranean region. An analysis of CMIP3 models is conducted to determine the extent to which models reproduce the signature of the SNAO and its impact on precipitation and to assess the role of the SNAO in the projected precipitation reductions. Most models correctly simulate the spatial pattern of the SNAO and the dry anomalies in northwest Europe that accompany the positive phase. The models also capture the concurrent wet conditions in the Mediterranean, but the amplitude of this signal is too weak, especially in the east. This error is related to the poor simulation of the upper‐level circulation response to a positive SNAO, namely the observed trough over the Balkans that creates potential instability and favors precipitation. The SNAO is generally projected to trend upwards in CMIP3 models, leading to a consistent signal of precipitation reduction in NW Europe, but the intensity of the trend varies greatly across models, resulting in large uncertainties in the magnitude of the projected drying. In the Mediterranean, because the simulated influence of the SNAO is too weak, no precipitation increase occurs even in the presence of a strong SNAO trend, reducing confidence in these projections.
Seeding atomic layer deposition of high-k dielectric on graphene with ultrathin poly(4-vinylphenol) layer for enhanced device performance and reliability
Authors: Cheol Shin Woo , Yong Kim Taek , Sul Onejae , Jin Cho Byung
Published: July 2012

We demonstrate that ultrathin poly(4-vinylphenol) (PVP) acts as an effective organic seeding layer for atomic layer deposition (ALD) of high-k dielectric on large-scale graphene fabricated by chemical vapor deposition (CVD). While identical ALD conditions result in incomplete and rough dielectric deposition on CVD graphene, the reactive groups provided by the PVP seeding layer yield conformal and pinhole-free dielectric films throughout the large-scale graphene. Top-gate graphene field effect transistors fabricated with the high quality, PVP-seeded Al2O3 gate dielectric show superior carrier mobility and enhanced reliability performance, which are desirable for graphene nanoelectronics.
Long-term effect of nutrition on the metabolic status and reproductive potential of Merino rams under grazing conditions
Authors: Viñoles C. , De Barbieri I. , Gil J. , Olivera J. , Fierro S. , Bialade F. , Montossi F.
Published: July 2012

To evaluate the impact of feeding rams for 14 weeks with legumes and supplement on their clinical, behavioural and endocrine responses, 32 Merino rams, 17 months old, were allocated to four groups (n = 8). The 2 × 2 factorial arrangement evaluated the pasture type (IP, improved pasture; NP, native pasture) and the effect of feeding (+S) or not (–S) feeding a supplement. Every 2 weeks liveweight, scrotal circumference and serving capacity were evaluated and blood samples taken to measure the concentrations of metabolites and metabolic hormones. Grazing behaviour was evaluated every 4 weeks. Rams grazing IP (61.8 ± 0.7 kg) were heavier than those grazing NP (59.6 ± 0.7 kg; P < 0.05), and +S rams (61.8 ± 0.7 kg) heavier than –S rams (59.3 ± 0.6 kg; P < 0.05). Compared with rams from the IP+S, IP–S and NP+S, rams grazing NP–S lost weight (P < 0.001) during the experiment. The scrotal circumference was larger in IP+S (30 ± 0.4 cm), IP–S (30 ± 0.4 cm) and NP+S (31 ± 04 cm) than in NP–S (29 ± 0.4 cm; P < 0.001). Only in rams from the group NP+S was a significant increase in scrotal circumference observed during the trial (P < 0.05). The supplement tended to maintain the mating potential elevated towards the end of the experiment (+S: 74.3 ± 5.4 and –S: 61.7 ± 6.3 ewes/ram; P = 0.07). Supplemented rams were less frequently seen grazing (47 ± 3%) than non-supplemented rams (57 ± 4%; P = 0.09). Rams grazing IP ruminated more frequently (13 ± 2%) than those grazing NP (9 ± 2%; P < 0.001). Events such as lying down, playing, self-grooming and drinking water were more frequent in supplemented (36 ± 2%) than non-supplemented rams (30 ± 2%; P = 0.09). The supplement increased the concentrations of insulin and glucose and decreased the concentrations of non-esterified fatty acids, albumin and urea (P < 0.05). IP increased the concentrations of insulin-like growth factor-I, protein, albumin and urea and tended to increase the concentrations of insulin. We conclude that feeding Merino rams a high plane of nutrition reduced the frequency of grazing events and stimulated a long-term improvement of the metabolic status, evidenced by an increase in liveweight and scrotal circumference, with relevant implications for their mating potential.
Effect of age on semen quality in naked neck and dwarf chicken under tropical climatic conditions
Authors: Shanmugam M. , Rajkumar U. , Reddy M. R. , Rao S. V. Rama
Published: July 2012

The present study was undertaken to elucidate the effect of age on semen quality of naked neck and dwarf chicken lines under tropical climatic conditions. Semen collected by abdominal massage at 4-week intervals from 24 to 48 weeks of age was evaluated for different semen quality parameters. Except sperm concentration and appearance, all other parameters were significantly (P < 0.05) affected by the age of the birds. The semen volume, motility, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye reduction test and percentage of live sperm were significantly (P < 0.05) lower at 24 weeks of age compared with 40 weeks of age. At 24 weeks of age the dead sperm percentage was significantly (P < 0.05) high and with advancing age it decreased. There was a significant difference (P < 0.05) between the gene lines for volume, appearance, motility, sperm concentration, and percentage of live and dead sperm. Except for sperm concentration, significant (P < 0.05) interaction between gene lines and age was observed in other parameters. In conclusion, semen quality was different between naked neck and dwarf line males and age affected semen quality of the gene lines studied in different manners.
Enhanced Spin-capturing Polymerization and Radical Coupling Mediated by Cyclic Nitrones
Authors: Ranieri Kayte , Conradi Matthias , Chavant Pierre-Yves , Blandin Veronique , Barner-Kowollik Christopher , Junkers Thomas
Published: July 2012

A series of cyclic nitrones have been tested for their spin-trapping activity in the enhanced spin-capturing polymerization of styrene and in nitrone-mediated radical coupling reactions. rac-2-Isopropyl-2,3-dimethyl-1-oxy-2,3-dihydro-imidazol-4-one was found to be the most efficient nitrone. The specific polystyrene macroradical addition rate to this nitrone was determined to be 8.0 × 103 L mol–1 s–1, which is by a factor of 10 higher than for previously studied compounds. Via enhanced spin-capturing polymerization, polymers in the range of oligomers to 30000 g mol–1 were obtained. A strong dependence of molecular weight on monomer conversion was observed, which can be explained by the high trapping rate. In nitrone-mediated radical coupling, almost ideal coupling of bromine-functional polymers was obtained and the successful introduction of the residual alkoxyamine functionality confirmed.
Photosynthesis of barley awns does not play a significant role in grain yield under terminal drought
Authors: Hosseini Shahab Maddah , Poustini Kazem , Siddique Kadambot H. M. , Palta Jairo A.
Published: July 2012

In order to determine the importance of awn photosynthesis on grain yield under terminal drought, six two-rowed cultivars of barley representing high yielding commercial releases from 1961 to 2006 were studied in a glasshouse experiment at CSIRO, Western Australia. The cultivars were grown with and without watering from anthesis. Detailed measurements of plant water status, awn, flag and penultimate leaf photosynthetic rate were made from anthesis. At final harvest, biomass, yield and yield components were measured. Awn net photosynthesis rate (Pn) was lower than penultimate and flag leaf and decreased gradually after anthesis. The rate of decreasing Pn was rapid under terminal drought. There was no difference in awn Pn among cultivars under well-watered conditions, but under terminal drought the awn Pn of barley cultivars Baudin and Clipper decreased faster than Vlaming, Gairdner and Stirling. Surface area of awns in each cultivar was higher than the flag and penultimate leaf. Thus, total awn photosynthesis under both well-watered and terminal drought conditions was higher than flag leaf photosynthesis. In Vlaming, total awn photosynthesis was higher than penultimate leaf photosynthesis. Grain yield of the cultivars Baudin, Covette and Gairdner was affected by terminal drought, but grain yield did not correlate with awn total photosynthesis. Under well-watered conditions awn Pn had a significant negative correlation with ear weight. We suggest that under terminal drought, higher awn area does not lead to higher grain yield because sink size may be the factor limiting grain yield in barley.
Comparative thermoregulatory physiology of two dunnarts, Sminthopsis macroura and Sminthopsis ooldea (Marsupialia : Dasyuridae)
Authors: Tomlinson Sean , Withers Philip C. , Maloney Shane K.
Published: July 2012

Metabolic rate and evaporative water loss (EWL) were measured to quantify the thermoregulatory patterns of two dasyurids, the stripe-faced dunnart (Sminthopsis macroura) and the Ooldea dunnart (S. ooldea) during acute exposure to Ta between 10 and 35°C. S. macroura maintained consistent Tb across the Ta range, whereas S. ooldea was more thermolabile. The metabolic rate of both species decreased from Ta = 10°C to BMR at Ta = 30°C. Mass-adjusted BMR at Ta = 30°C was the same for the two species, but there was no common regression of metabolic rate below the thermoneutral zone (TNZ). There was no significant difference between the species in allometrically corrected EWL at Ta = 30°C. Total EWL increased significantly at Ta = 10 and 35°C compared with the TNZ for S. macroura, but was consistent across the Ta range for S. ooldea. At any Ta below the TNZ, S. macroura required more energy per gram of body mass than S. ooldea, and had a higher EWL at the lower critical Ta. By being thermolabile S. ooldea reduced its energetic requirements and water loss at low Ta. The more constant thermoregulatory strategy of S. macroura may allow it to exploit a broad climatic envelope, albeit at the cost of higher energetic and water requirements. Since S. ooldea does not expend as much energy and water on thermoregulation this may be a response to the very low productivity, ‘hyperarid’ conditions of its central Australian distribution.
Validation of Oligohaline Elemental Otolith Signatures of Striped Bass by Use of In Situ Caging Experiments and Water Chemistry
Authors: Mohan John A. , Rulifson Roger A. , Corbett D. Reide , Halden Norman M.
Published: July 2012

The spatiotemporal variability in strontium (Sr), barium (Ba), magnesium (Mg), and manganese (Mn) elemental signatures of water and fish otoliths was assessed from July to October 2008 across river habitats of Albemarle Sound, North Carolina. We examined whether relationships in these signatures exist and the potential of otoliths to serve as innate chemical tags. Hatchery-reared age-0 striped bass Morone saxatilis were placed in cages at four different locations to test development of habitat-specific otolith signatures. Dissolved elemental water and otolith signatures exhibited spatial variability but did not vary temporally. Chemical water signatures classified habitats with 76–81% accuracy, and otolith signatures of caged fish displayed 59–63% total classification accuracy depending on the classification method used. The elements Sr, Ba, and Mn were the main habitat discriminators, as their concentrations in otoliths were significantly correlated with concentrations in the water. Otolith Mg was not related to water chemistry and did not vary among habitats. Natural physiochemical gradients, geochemical processes, and possibly anthropogenic inputs influenced the trace elemental signatures of Albemarle Sound habitats. The unique chemical signals of the sound's river habitats validate the use of otolith signatures for determining striped bass habitat utilization in this system. Use of otolith elemental signatures as natural tags provides a quantitative method to determine the proportion of juvenile striped bass recruiting to the adult spawning stock from specific habitats, thus aiding resource managers in identifying habitats that should receive priority in restoration and conservation decisions.

Received June 11, 2010; accepted September 12, 2011
Evaluation of Otolith Microchemistry for Identifying Natal Origin of Anadromous River Herring in Connecticut
Authors: Gahagan Benjamin I. , Vokoun Jason C. , Whitledge Gregory W. , Schultz Eric T.
Published: July 2012

Over the past two decades, declines in the populations of river herring (alewife Alosa pseudoharengus and blueback herring Alosa aestivalis) have been documented across both species’ ranges. Information concerning the natal origins of spawning adult fish could aid in their restoration but has been unattainable. We investigated the efficacy of otolith microchemistry for identifying the natal environment of alewife and blueback herring in Connecticut. In both 2008 and 2009, water and juvenile and adult fish were sampled from 10 sites across the state. The relationships between water and otolith Sr:Ca ratios differed for alewives and blueback herring, necessitating the development of separate classification models for assigning individuals to capture locations. Reclassification of age-0 alewives to their site of origin was variable (50–100%) but demonstrated that age-0 fish could be accurately reclassified to their natal environment at some sites. Discriminant function reclassification rates to site of capture for adult alewives varied greatly (10–85%); the similarity of water chemical signatures among many sites likely contributed to the relatively low rates of assignment to the majority of collection locations. Adult blueback herring reclassification rates were low (15–33%) for three of four collection sites, probably due to overlapping elemental signatures. Blueback herring collected at the fourth site had a distinct signature and a reclassification rate (81%) comparable to that of the highest alewife rate. Changes in Sr:Ca and Ba:Ca ratios across sectioned otoliths suggested a higher degree of movement across salinity boundaries during the first year of life than previously documented for anadromous alewives and blueback herring. Otolith microchemistry may be a useful tool with which to investigate alewife and blueback herring natal homing and life history, but its utility appears to be confined to particular sites with unique signatures or to broader regional assignments of natal origin.

Received March 18, 2011; accepted August 23, 2011
Evaluating the Current Status of American Shad Stocks in Three Virginia Rivers
Authors: Latour Robert J. , Hilton Eric J. , Lynch Patrick D. , Tuckey Troy D. , Watkins Brian E. , Olney John E.
Published: July 2012

Directed commercial fisheries for American shad Alosa sapidissima in the primary Virginia tributaries of the Chesapeake Bay have been under moratorium since 1994. Monitoring of adult American shad within these rivers has been ongoing since 1998 through a cooperative program involving commercial fishers. The monitoring program is designed to mimic traditional commercial fishing practices so that stock status can be inferred by comparing contemporary catch-per-unit-effort levels with those derived from historic logbooks. In this paper, we present analyses of the available monitoring and historic catch rate data along with updated stock status information for American shad in the James, York, and Rappahannock rivers. Two analytical methods were used to derive annual indices of relative abundance; both methods yielded very similar patterns for each river system. Comparisons of contemporary and historic indices of relative abundance suggest that American shad in the James and York rivers continue to persist at low levels of abundance. Measures of stock abundance in the Rappahannock River have been higher than the logbook reference value for much of the monitoring period. However, current moratoria and restoration strategies, which include hatchery releases of fry, the removal of obstructions blocking spawning and nursery habitat, and reductions in bycatch from other fisheries, should continue into the foreseeable future.

Received March 30, 2011; accepted August 21, 2011
Surface geometry, miniaturization and metrology
Authors: Whitehouse David J.
Published: July 2012

Ultra-precision engineering has at its core the size, shape and texture of the components used. This study examines how the relationship between them and their role is changing with respect to manufacture, function and characterization, with particular emphasis on aspects of miniaturization and ultra-precision engineering. Surface geometry has traditionally been linked to the generation of part size. This is changing: the study shows that it is now possible to separate shape and texture from the size generation and to design them independently for function. In addition, with miniaturization, the roles and properties of shape and texture that affect performance change considerably, especially those tribological functions involving contact and flow. This study reveals these changes and shows how the characterization of the surfaces making up a surface system can take these into account.
The National Ignition Facility: the path to a carbon-free energy future
Authors: Stolz Christopher J.
Published: July 2012

The National Ignition Facility (NIF), the world's largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory. The NIF will enable exploration of scientific problems in national strategic security, basic science and fusion energy. One of the early NIF goals centres on achieving laboratory-scale thermonuclear ignition and energy gain, demonstrating the feasibility of laser fusion as a viable source of clean, carbon-free energy. This talk will discuss the precision technology and engineering challenges of building the NIF and those we must overcome to make fusion energy a commercial reality.
Mathematics for modern precision engineering
Authors: Scott Paul J. , Forbes Alistair B.
Published: July 2012

The aim of precision engineering is the accurate control of geometry. For this reason, mathematics has a long association with precision engineering: from the calculation and correction of angular scales used in surveying and astronomical instrumentation to statistical averaging techniques used to increase precision. This study illustrates the enabling role the mathematical sciences are playing in precision engineering: modelling physical processes, instruments and complex geometries, statistical characterization of metrology systems and error compensation.