bluuebunny/crossref_metadata_2025 huggingface dataset:
An investigation into the possibility of bluetongue virus transmission by transfer of infected ovine embryos
Authors: Venter Estelle H. , Gerdes Truuske , Wright Isabel , Terblanche Johan
Published: May 2011

Bluetongue (BT), a disease that affects mainly sheep, causes economic losses owing to not only its deleterious effects on animals but also its associated impact on the restriction of movement of livestock and livestock germplasm. The causative agent, bluetongue virus (BTV), can occur in the semen of rams and bulls at the time of peak viraemia and be transferred to a developing foetus. The risk of the transmission of BTV by bovine embryos is negligible if the embryos are washed according to the International Embryo Transfer Society (IETS) protocol. Two experiments were undertaken to determine whether this holds for ovine embryos that had been exposed to BTV. Firstly, the oestrus cycles of 12 ewes were synchronised and the 59 embryos that were obtained were exposed in vitro to BTV-2 and BTV-4 at a dilution of 1 x 102.88 and 1 x 103.5 respectively. In the second experiment, embryos were recovered from sheep at the peak of viraemia. A total of 96 embryos were collected from BTV-infected sheep 21 days after infection. In both experiments half the embryos were washed and treated with trypsin according to the IETS protocol while the remaining embryos were neither washed nor treated. All were tested for the presence of BTV using cell culture techniques. The virus was detected after three passages in BHK-21 cells only in one wash bath in the first experiment and two unwashed embryos exposed to BTV-4 at a titre of 1 x 103.5. No embryos or uterine flush fluids obtained from viraemic donors used in the second experiment were positive for BTV after the standard washing procedure had been followed. The washing procedure of the IETS protocol can thus clear sheep embryos infected with BTV either in vitro or in vivo.
The dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the Kruger National Park (1988–2002). Part I. Total ticks, Amblyomma hebraeum and Rhipicephalus decoloratus
Authors: Horak Ivan G. , Gallivan Gordon J. , Spickett Arthur M.
Published: May 2011

Despite a large number of studies on tick biology, there is limited information on long- term changes in tick populations. This study thus aimed to assess the long-term population dynamics of questing ixodid ticks in two landscape zones of the Kruger National Park (KNP). Questing ixodid ticks were collected in the KNP from August 1988 to March 2002 by monthly dragging of the vegetation in three habitats (grassland, woodland and gully) at two sites (Nhlowa Road and Skukuza). Findings pertaining to total tick numbers and Amblyomma hebraeum and Rhipicephalus decoloratus specifically are presented here. Fourteen tick species were collected, as well as four others that could be identified only to generic level. More ticks (211 569 vs 125 810) were collected at Nhlowa Road than at Skukuza. Larvae were the most commonly collected stage of all the major tick species. A. hebraeum was the most commonly collected tick (63.6%) at Nhlowa Road, whereas R. decoloratus accounted for 15.3% of the ticks collected there. At Skukuza, 31.6% and 27.1% of the collected ticks were R. decoloratus and A. hebraeum respectively. Most A. hebraeum larvae were collected in summer and the fewest in winter and early spring, mostly in woodland and least often in grassland habitats. Most R. decoloratus larvae were collected in spring and the fewest in autumn and winter, and were more frequently collected in woodland and grassland than in gullies. The largest collections of most tick species were made during the early 1990s, while numbers were lowest in the mid-1990s after a drought during 1991 and 1992 and then increased towards the late 1990s, followed by a final decrease. The changes in tick numbers over time probably reflect differences in their host communities at the two sites and the effect of climatic conditions on both hosts and free-living ticks. The population dynamics of questing ticks reflect a complex interaction between ticks, their hosts and the environment.
The prevalence of abdominal obesity and hypertension amongst adults in Ogbomoso, Nigeria
Authors: Amole Isaac O. , OlaOlorun Akintayo D. , Odeigah Louis O. , Adesina Stephen A.
Published: May 2011

Background:In many developing countries obesity and obesity-related morbidity are now becoming a problem of increasing importance. Obesity is associated with a number of disease conditions, including hypertension, type 2 diabetes mellitus, cardiovascular diseases, cancer, gallstones, respiratory system problems and sleep apnoea.Objectives: The aim of this study was to determine the prevalence of hypertension and obesity, as classified according to waist circumference (WC), and further to determine whether there was any association between abdominal obesity and hypertension amongst adults attending the Baptist Medical Centre, Ogbomoso, Nigeria.Method: A cross-sectional descriptive study of 400 adults aged 18 years or older was conducted. Blood pressure and WC measurements were taken and participants completed a standardised questionnaire.Results: A group of 400 participants were randomly selected (221 women; 179 men), with a mean age of 48.7 ± 16.6 years. The overall prevalence of obesity as indicated by WC was 33.8%(men = 8.9%; women = 53.8%). Women were significantly more sedentary than men (50.8% for men vs 62.4% for women, p < 0.05). Most of the obese participants’ families also preferred high-energy foods (85.2%, p > 0.05). Overall prevalence of hypertension amongst the study population was 50.5%, but without a significant difference between men and women (52.0% for men vs 49.3% for women, p > 0.05). The prevalence of hypertension amongst the obese subset, however, was 60.0%.Conclusion: Prevalence of abdominal obesity was found to be particularly significant amongst women in this setting and was associated with hypertension, physical inactivity and the consumption of high-energy diets.
Evaluation of directly observed treatment for tuberculosis in the Bojanala health district, North West Province of South Africa
Authors: Tumbo John M. , Ogunbanjo Gboyega A.
Published: May 2011

Background: Tuberculosis (TB) remains one of the top public health problems in South Africa. Approximately 150 000 new cases and 10 000 TB-related deaths are reported in South Africa annually. In declaring TB a global emergency in 1993, the World Health Organization developed control strategies that include active case finding, laboratory support, directly observed treatment (DOT), contact tracing, and prevention of multidrug– and extreme drugresistant tuberculosis (MDR-TB and XDR-TB). High DOT rates reported in some countries have been discordant with ‘low cure’ and ‘high MDR’ rates.Objectives: The aim of the study was to evaluate the use of DOT for TB in the Bojanala health district, North West Province, South Africa, by estimating the proportion of DOT use (1) amongst all TB patients and (2) in the initial TB treatment regimen compared to retreatment regimens.Method: A cross-sectional, descriptive study was conducted in 2008. Data regarding implementation of DOT were collected from eight purposefully selected primary health care clinics and one prison clinic in the health district. Upon receiving their informed consent, a questionnaire was administered to patients receiving TB treatment at the selected facilities.Results: A total of 88 (of 90 selected) patients participated in the study, of whom 50(56.8%) were on DOT and had DOT supporters. However, 35 (40%) had never heard of DOT. DOT was used mainly for patients on the retreatment regimen (87.5%), rather than for those on first-line treatment (48.6%).Conclusion: In this South African rural health district, the DOT utilisation rate for TB was 56.8%, mainly for patients on the TB retreatment regimen. Strict implementation of DOT in all patients undergoing TB treatment is a known strategy for improving TB cure rate and preventing recurrence and drug resistance.
Intestinal parasitic infections and malnutrition amongst first-cycle primary schoolchildren in Adama, Ethiopia
Authors: Belay Getachew , Reji Pawlos , Erko Berhanu , Legesse Mengistu , Belay Mulugeta
Published: May 2011

Background: A survey of intestinal parasitic infections and malnutrition in different regions or localities is a very important step in developing appropriate prevention and control strategies.Objectives: The objective of this study was to investigate the magnitude of intestinal parasitic infections and malnutrition amongst first-cycle primary schoolchildren in Adama town,Ethiopia.Method: A total of 358 children from four primary schools in Adama town were included for stool examination, weight for age, height for age, weight for height and socio-economic status of the family.Results: The result of stool examinations showed that 127 (35.5%) of the study subjects were infected by one or more parasite. The most frequent parasites were Entamoeba histolytica/dispar (12.6%) and Hymenolopis nana (8.9%). The rate of intestinal parasitic infection was not significantly associated with sex, age or socio-economic factors and nutrition (P > 0.05). The overall prevalence of malnutrition was 21.2%. Those children whose families had a monthly income of less than 200 ETB (Ethiopian birr) were highly affected by malnutrition (P < 0.05),but family education was not identified as a factor for malnutrition amongst schoolchildren.Conclusion: The prevalence of E. histolytica/dispar and H. nana could be of public health importance and calls for appropriate control strategies, and the high prevalence of malnutrition amongst children from poor families requires intervention.
Contraception as a risk factor for urinary tract infection in Port Harcourt, Nigeria: A case control study
Authors: Dienye Paul O. , Gbeneol Precious K.
Published: May 2011

Background: The concerted effort of government and donor agencies to limit fertility by the use of contraceptives has been reported in some studies to predispose to urinary tract infection (UTI). Similar studies have not been conducted in the General Outpatient Department (GOPD) of the University of Port Harcourt Teaching Hospital (UPTH). Objectives: This study was aimed at assessing the role of contraceptives in the development of UTI amongst adult females attending the GOPD of UPTH.Method: A case control study in which contraceptive users who attended the GOPD of the UPTH in four months, and an equal number of age-matched controls, were screened for UTI. The information obtained from them was entered into a specially designed pre-tested questionnaire for analysis. The results were analysed using SPSS version 14.Results: A total of 150 contraceptive users and controls were evaluated. Their age range was 18–50 years, with a mean of 27.8 ± 5.3 years. Most of the participants belonged to the lower socioeconomic classes. The combined prevalence of UTI amongst the contraceptive users and the controls was 23.7%, with the contraceptive users at 35.3% and the controls at 12.0%. The association of UTI with contraceptive use was statistically significant, with McNemar’s χ2 = 16.28, p = 0.000, odds ratio (OR) = 2.9, 95% confidence interval (CI) = 1.7 – 5.3, attributable risk (AR) = 23.3, population attributable risk (PAR) = 11.7. The users of barrier contraceptives were more predisposed to UTI (OR = 17.30, 95% CI = 7.49 -39.96).Conclusion: Contraceptive use is a significant risk factor for acquiring urinary tract infection, with the barrier methods being more predisposing. Health education for the hygienic and safe use of family planning methods will prevent long-term complications.
Morbidity pattern amongst elderly patients presenting at a primary care clinic in Nigeria
Authors: Adebusoye Lawrence A. , Ladipo Modupe M. , Owoaje Eme T. , Ogunbode Adetola M.
Published: May 2011

Background: The elderly comprise the fastest-expanding age group globally, with the greatest increase occurring in developing countries. Disease and deteriorating health are implicitly assumed to be associated with ageing, as chronic medical illnesses mostly present with increasing age. Objectives: To describe the morbidity pattern of elderly patients presenting at the General Outpatients Clinic of the University College Hospital, Ibadan, Nigeria.Method: This was a cross-sectional descriptive study of 500 elderly respondents who presented at the clinic between September 2004 and April 2005. They were interviewed according to the format of the electronic, second revision of the International Classification of Primary Care (ICPC-2-E) questionnaire. Main outcome measurements were the prevalence of various morbidities, self-reported health status and socio-demographic characteristics. Body mass index (BMI) was used to assess respondents’ nutritional status.Results: Respondents were found to under-report their actual health problems. The mean ± s.d of self-reported health problems was 1.7 ± 0.9 (range 1–6), while the mean ± s.d of diagnosed morbidities was 2.7 ± 1.4 (range 1–8). The most prevalent morbidities were hypertension(40.0%), cataracts (39.4%) and osteoarthritis (26.8%). The prevalence of anaemia was 8.0% (females = 11.2%; males = 2.6%), and it was significantly associated with gender (p = 0.001). Nutritional status indicated a high prevalence of overweight and obesity (51.8%), which was significantly higher amongst the female respondents than the males (p = 0.001).Conclusion: The prevalence of chronic medical illnesses was high amongst the elderly in this setting. In addition, the elderly under-reported their actual health problems. The high prevalence of overweight and obesity amongst the elderly in this setting calls for public health action that advocates lifestyle changes to manage the health of the elderly.
An empirical study on website usability elements and how they affect search engine optimisation
Authors: Visser Eugene B. , Weideman Melius
Published: May 2011

The primary objective of this research project was to identify and investigate the website usability attributes which are in contradiction with search engine optimisation elements. The secondary objective was to determine if these usability attributes affect conversion. Although the literature review identifies the contradictions, experts disagree about their existence.An experiment was conducted, whereby the conversion and/or traffic ratio results of an existing control website were compared to a usability-designed version of the control website,namely the experimental website. All optimisation elements were ignored, thus implementing only usability. The results clearly show that inclusion of the usability attributes positively affect conversion,indicating that usability is a prerequisite for effective website design. Search engine optimisation is also a prerequisite for the very reason that if a website does not rank on the first page of the search engine result page for a given keyword, then that website might as well not exist. According to this empirical work, usability is in contradiction to search engine optimisation best practices. Therefore the two need to be weighed up in terms of importance towards search engines and visitors.
Entrepreneurial networking differences: An ethnic in-group and out-group analysis
Authors: Urban Boris
Published: May 2011

Orientation: Researching entrepreneurship using a network perspective is important, as social networks are assets for small business owners struggling to survive in competitive markets.Research purpose: The research question of this study has focused on what we can learn about entrepreneurial networking, considering that there is an under-explored and unarticulated set of networking principles and practices which have not been previously analysed in terms of a multiethnic country context.Motivation for the study: Often the lack of network use is reported as a feature of entrepreneurs, who have less opportunity to utilise formal social capital features. Social networks provided by extended family, community-based or organisational relationships are often theorised to supplement the effects of education, experience and financial capital.Research design, approach and method: Based on hypothesised differences in networking ties, network assistance and support relationships, a survey was used to collect data on quantitative measures. Descriptive statistics were calculated and differential tests were conducted to test the hypotheses.Main findings: Results indicate that entrepreneurial networking is largely independent on group composition. Generally at least some aspects of networking are generic and as a consequence, a more integrated view of networking can be adopted.Practical/managerial implications: The practical value of the present study points to several areas of interest to entrepreneurs, policy makers and educators, through demonstrating the multifaceted nature of entrepreneurial networks for different groups and their explanatory potential in understanding networking.Contribution/value-add: Despite the importance of entrepreneurial networking, little empirical or theoretical research has examined the dynamics of networking in a developing country context such as South Africa, which has lower than expected total entrepreneurship activity.
Positive organisation: The role of leader behaviour in work engagement and retention
Authors: Mendes Fallen , Stander Marius W.
Published: May 2011

Orientation: The positive organisation creates a framework in which its elements can be investigated in relation to the retention of talent.Research purpose: The aim of this study was to investigate if leader empowering behaviour can positively impact on role clarity, psychological empowerment and work engagement, with the final outcome being the retention of talent.Motivation for the study: In the ever changing work environment organisations place great emphasis on their human capital. The positive organisation utilises specific elements to optimise human capital’s potential. It is therefore important to identify the elements contributing to a positive organisation as well as the elements which lead to the retention of talent.Research design, approach and method: A survey research design was used. A convenience sample (n = 179) was taken from a business unit in a chemical organisation. The Leader Empowering Behaviour Questionnaire, Measures of Role Clarity and Ambiguity Questionnaire, Measuring Empowerment Questionnaire, Utrecht Work Engagement Scale and the Intention to Leave Scale were administered.Main findings: Leader empowering behaviour, role clarity and psychological empowerment predicted work engagement. Role clarity interacted with competence to affect employees’ dedication and interacted with the development of employees to affect absorption. Work engagement predicted employees’ intention to leave.Practical/managerial implications: Organisations should foster the elements of a positive organisation if they want to retain their talent.Contribution/value-add: The results of this research contribute to scientific knowledge about the effects of a positive organisation on retention.
Ecallantide for the Treatment of Hereditary Angiodema in Adults
Authors: Lunn Michael , Banta Erin
Published: May 2011

Hereditary angioedema (HAE) is a clinical disorder characterized by a deficiency of C1 esterase inhibitor (C1-INH). HAE has traditionally been divided into two subtypes. Unique among the inherited deficiencies of the complement system, HAE Types I and II are inherited as an autosomal dominant disorder. The generation of an HAE attack is caused by the depletion and/or consumption of C1-inhibitor manifested as subcutaneous or submucosal edema of the upper airway, face, extremities, or gastrointestinal tract mediated by bradykinin. Attacks can be severe and potentially life-threatening, particularly with laryngeal involvement and treatment of acute attacks in the United States has been severely limited. In December 2009 the FDA approved ecallantide for the treatment of acute HAE attacks. Ecallantide is a small recombinant protein acting as a potent, specific and reversible inhibitor of plasma kallikrein which binds to plasma kallikrein blocking its binding site, directly inhibiting the conversion of high molecular weight kininogen to bradykinin. Administered subcutaneously, ecallantide was demonstrated in two clinical trials, EDEMA3 and EDEMA4, to decrease the length and severity of acute HAE attacks. Although there is a small risk for anaphylaxis, which limits home administration, ecallantide is a novel, safe, effective and alternative treatment for acute HAE attacks.
The Verdier Hypercovering Theorem
Authors: Jardine J. F.
Published: May 2011

This note gives a simple cocycle-theoretic proof of the Verdier hypercovering theorem. This theorem approximates morphisms [X, Y] in the homotopy category of simplicial sheaves or presheaves by simplicial homotopy classes of maps, in the case where Y is locally fibrant. The statement proved in this paper is a generalization of the standard Verdier hypercovering result in that it is pointed (in a very broad sense) and there is no requirement for the source object X to be locally fibrant.
A Generalised Kummer-Type Transformation for the pFp(x) Hypergeometric Function
Authors: Miller A. R. , Paris R. B.
Published: May 2011

In a recent paper, Miller derived a Kummer-type transformation for the generalised hypergeometric function pFp(x) when pairs of parameters differ by unity, by means of a reduction formula for a certain Kampé de Fériet function. An alternative and simpler derivation of this transformation is obtained here by application of the well-known Kummer transformation for the confluent hypergeometric function corresponding to p = 1.
Smooth Approximation of Lipschitz Projections
Authors: Li Hanfeng
Published: May 2011

We show that any Lipschitz projection-valued function p on a connected closed Riemannian manifold can be approximated uniformly by smooth projection-valued functions q with Lipschitz constant close to that of p. This answers a question of Rieffel.
La publicidad institucional en la arena parlamentaria española
Authors: Feliu-Albaladejo Ángeles
Published: May 2011

El presente  artículo presenta los resultados de un estudio acerca de la presencia de la publicidad institucional en el Congreso de los Diputados, tomado como una de las arenas de la comunicación política. La investigación se centra en el análisis de las iniciativas parlamentarias presentadas y en los debates parlamentarios correspondientes, con especial incidencia en las iniciativas legislativas previas a la Ley de Publicidad y Comunicación Institucional de 2005, y su valor como antecedente de otras normas reguladoras. La primera proposición de ley, aun resultando rechazada,  sería tomada como base documental en posteriores propuestas de diferentes fuerzas políticas. La postura de los distintos grupos, y los argumentos que la justifican, ponen de manifiesto una más que clara falta de coherencia en muchos casos.  La comparación entre diferentes iniciativas en distintas cámaras españolas -y los debates en torno a ellas- supone un primer paso en el establecimiento de la policy memory, que, trascendiendo el caso concreto de la publicidad institucional, se muestra como un instrumento sumamente útil en el ámbito de la investigación en Comunicación Política.
Fast sulfur dioxide measurements correlated with cloud concentration nuclei spectra in the marine boundary layer
Authors: Thornton D. C. , Bandy A. R. , Hudson J. G.
Published: May 2011

Abstract. During the Rain in (shallow) Cumulus over the Ocean (RICO) project simultaneous measurements of high rate sulfur dioxide (SO2) measurements and cloud condensation nuclei (CCN) spectra were made for the first time. During research flight 14 (14 January 2005) the convective boundary layer was impacted by precipitation and ship plumes in midday but not in the late afternoon. Accumulation mode aerosols (0.14 to 0.2 μm diameter) were a factor of two greater in the latter period while CCN were 30 % to 65 % greater for aerosols that activate at supersaturations >0.1 %. Linear correlations of SO2 and CCN were found for SO2 concentrations ranging from 20 to 600 parts-per-trillion (pptv). The greatest sensitivities were for SO2 and CCN that activate at supersaturations >0.1 % for both clean and polluted air. In a region affected by a cold pool event SO2 was only linearly correlated with CCN at >0.2 % S.
Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations
Authors: Qian Y. , Long C. , Wang H. , Comstock J. , McFarlane S. A. , Xie S.
Published: May 2011

Abstract. Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulated in the IPCC AR4 GCMs against ARM ground measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity. Our intercomparisons of three CF or sky-cover related datasets reveal that the relative differences are usually less than 10 % (5 %) for multi-year monthly (annual) mean values, while daily differences are quite significant. The results also show that the model-observation and inter-model deviations have similar magnitudes for the total CF (TCF) and the normalized cloud effect, and these deviations are twice as large as the deviations in surface downward solar radiation and cloud transmissivity. This implies that other cloud properties, such as cloud optical depth and height, have a similar magnitude of disparity to TCF among the GCMs, and suggests that the better agreement among the GCMs in solar radiative fluxes is the result of compensating errors in cloud vertical structure, cloud optical depth and cloud fraction. The internal variability of CF simulated in ensemble runs with the same model is very minimal. Similar deviation patterns between inter-model and model-measurement comparisons suggest that the climate models tend to generate larger biases against observations for those variables with larger inter-model deviation. Differences are found in GCM performance over the three ARM sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). The GCMs perform better at SGP than at the other two sites in simulating the seasonal variation and probability distribution of TCF. However, the models remarkably underpredict the TCF and cloud transmissivity is less susceptible to the change of TCF than observed. Much larger inter-model deviation and model bias are found over NSA than the other sites, suggesting that the Arctic region continues to challenge cloud simulations in climate models. In the tropics, most of the GCMs tend to underpredict CF and fail to capture the seasonal variation of CF at middle and low levels. The high altitude CF is much larger in the GCMs than the observations and the inter-model variability of CF also reaches a maximum at high levels in the tropics, indicating difficulties in the representation of ice cloud associated with convection in the models.
What are the main climate drivers for shrub growth in Northeastern Siberian tundra?
Authors: Blok D. , Sass-Klaassen U. , Schaepman-Strub G. , Heijmans M. M. P. D. , Sauren P. , Berendse F.
Published: May 2011

Abstract. Deciduous shrubs are expected to rapidly expand in the Arctic during the coming decades due to climate warming. A transition towards more shrub-dominated tundra may have large implications for the regional surface energy balance, permafrost stability and carbon storage capacity, with consequences for the global climate system. However, little information is available on the natural long-term shrub growth response to climatic variability. Our aim was to determine the climate factor and time period that are most important to annual shrub growth in our research site in NE-Siberia. Therefore, we determined annual radial growth rates in Salix pulchra and Betula nana shrubs by measuring ring widths. We constructed shrub ring width chronologies and compared growth rates to regional climate and remotely sensed greenness data. Early summer temperature was the most important factor influencing ring width of S. pulchra (Pearson's r = 0.73, p < 0.001) and B. nana (Pearson's r = 0.46, p < 0.001). No effect of winter precipitation on shrub growth was observed. In contrast, summer precipitation of the previous year correlated positively with B. nana ring width (Pearson's r = 0.42, p < 0.01), suggesting that wet summers facilitate shrub growth in the following growing season. S. pulchra ring width correlated positively with peak summer NDVI, despite the small coverage of S. pulchra shrubs (< 5 % surface cover) in our research area. We provide the first climate-growth study on shrubs for Northeast Siberia, the largest tundra region in the world. We show that two deciduous shrub species with markedly different growth forms have a similar growth response to changes in climate. The obtained shrub growth response to climate variability in the past increases our understanding of the mechanisms underlying current shrub expansion, which is required to predict future climate-driven tundra vegetation shifts.
Global fungal spore emissions, review and synthesis of literature data
Authors: Sesartic A. , Dallafior T. N.
Published: May 2011

Abstract. The present paper summarizes fungal spore emission fluxes in different biomes. A literature study has been conducted and emission fluxes have been calculated based on 35 fungal spore concentration datasets. Biome area data has been derived from the World Resource Institute. Several assumptions and simplifications needed to be adopted while aggregating the data: results from different measurement methods have been treated equally, while diurnal and seasonal cycles have been neglected. Moreover flux data were aggregated to very coarse biome areas due to scarcity of data. Results show number fluxes per square meter and second of 194 for tropical and subtropical forests, 203 for all other forests, 1203 for shrub, 2509 for crop, 8 for tundra, and 165 for grassland. No data were found for land ice. The annual mean global fluxes amount to 1.69 × 10–11 kg m−2 s−1 as the best estimates, and 9.01 × 10–12 kg m−2 s−1 and 3.28 × 10–11 kg m−2 s−1 as the low and high estimate, respectively.
Quantifying the contribution of glacier runoff to streamflow in the upper Columbia River basin, Canada
Authors: Jost G. , Moore R. D. , Menounos B. , Wheate R.
Published: May 2011

Abstract. Glacier melt provides important contributions to streamflow in many mountainous regions. Hydrologic model calibration in glacier-fed catchments is difficult because errors in modelling snow accumulation can be offset by compensating errors in glacier melt. This problem is particularly severe in catchments with modest glacier cover, where goodness-of-fit statistics such as the Nash-Sutcliffe model efficiency may not be highly sensitive to the streamflow variance associated with glacier melt. While glacier mass balance measurements can be used to aid model calibration, they are absent for most catchments. We introduce the use of glacier volume change determined from repeated glacier mapping in a guided GLUE (generalized likelihood uncertainty estimation) procedure to calibrate a hydrologic model. We also explicitly account for changes in glacier area through the calibration and test periods. The approach is applied to the Mica basin in the Canadian portion of the Columbia River basin using the HBV-EC hydrologic model. Use of glacier volume change in the calibration procedure effectively reduced parameter uncertainty and helped to ensure that the model was accurately predicting glacier mass balance as well as streamflow. The seasonal and interannual variations in glacier melt contributions were assessed by running the calibrated model with historic glacier cover and also after converting all glacierized areas to alpine land cover in the model setup. Although glaciers in the Mica basin only cover 5 % of the watershed, glacier ice melt contributes up to 25 % and 35 % of streamflow in August and September, respectively, and is particularly important during periods of warm, dry weather following winters with low accumulation and early snowpack depletion. The approach introduced in this study provides an effective and widely applicable approach for calibrating hydrologic models in glacier fed catchments, as well as for quantifying the magnitude and timing of glacier melt contributions to streamflow.
Technical Note: Development of an automated lysimeter for the calculation of peat soil actual evapotranspiration
Authors: Proulx-McInnis S. , St-Hilaire A. , Rousseau A. N. , Jutras S. , Carrer G. , Levrel G.
Published: May 2011

Abstract. A limited number of publications in the literature deal with the measurement of actual evapotranspiration (AET) from a peat soil. AET is an important parameter in the description of water pathways of an ecosystem. In peatlands, where the water table is near the surface and the vegetation is composed of nonvascular plants without stomatal resistance, the AET measurement represents a challenge. This paper discusses the development of an automated lysimeter installed between 12 and 27 July 2010, at a 11-ha bog site, Pont-Rouge (42 km west of Quebec City, Canada). This system was made of an isolated block of peat, maintained at the same water level as the surrounding water table by a system of submersible pressure transmitters and pumps. The change in water level in millimetres in the isolated block of peat was used to calculate the water lost through evapotranspiration (ET) while accounting the precipitation. The rates of AET were calculated for each day of the study period. Temperature fluctuated between 17.2 and 23.3 °C and total rainfall was 43.76 mm. AET rates from 0.6 to 6.9 mm day−1 were recorded, with a ΣAET/ΣP ratio of 1.38. The estimated potential ET (PET) resulting from Thornthwaite's semi-empirical formula suggested values between 2.8 and 3.9 mm day−1. The average AET/PET ratio was 1.13. According to the literature, the results obtained are plausible. This system, relatively inexpensive and simple to install, may eventually be used to calculate AET on peaty soils in the years to come.
A Revision of Oriental Species of Psilocera Walker (Hymenoptera: Chalcidoidea: Pteromalidae) with Descriptions of Two New Species from Namdapha National Park, Arunachal Pradesh, India
Authors: Sureshan P. M.
Published: May 2011

The Oriental species of Psilocera Walker (Hymenoptera: Chalcidoidea: Pteromalidae) is revised, and two new species, namely, P. namdaphaensis sp.nov. and P. intermedia sp.nov. are described from Arunachal Pradesh, India. The affinities of the new species with the other known species are discussed. Systematic account of the Oriental species of Psilocera and a key to separate them are also provided.
Ultrasmooth Gold Films via Pulsed Laser Deposition
Authors: Ng Doris K. T. , Bhola Bipin S. , Bakker Reuben M. , Ho Seng‐Tiong
Published: May 2011

A simple, one step technique for depositing ultrasmooth gold films using pulsed laser deposition is demonstrated by optimizing process para­meters. The smoothest film having a root‐mean‐square roughness of 0.17 nm (including the substrate roughness of 0.11 nm) for a 35 nm thick film on a silicon substrate are obtained by introducing a nitrogen flow in the chamber during deposition. We postulate that the reduction in surface roughness caused by nitrogen gas pressure in the chamber is due to the force of the gas flow acting against the flow of the plasma plume containing Au atoms. The gas acts as a filter that reduces the kinetic energy of the gold adatoms. This is the best result reported so far for a single step deposition of gold. It is a step towards low‐loss planar gold films for surface plasmon applications.
Tunable Crystallinity in Regioregular Poly(3‐Hexylthiophene) Thin Films and Its Impact on Field Effect Mobility
Authors: Aiyar Avishek R. , Hong Jung‐Il , Nambiar Rakesh , Collard David M. , Reichmanis Elsa
Published: May 2011

The properties of poly(alkylthiophenes) in solution are found to have a profound impact on the self assembly process and thus the microstructural and electrical properties of the resultant thin films. Ordered supramolecular precursors can be formed in regioregular poly(3‐hexylthiophene) (P3HT) solutions through the application of low intensity ultrasound. These precursors survive the casting process, resulting in a dramatic increase in the degree of crystallinity of the thin films obtained by spin coating. The crystallinity of the films is tunable, with a continuous evolution of mesoscale structures observed as a function of ultrasonic irradiation time. The photophysical properties of P3HT in solution as well in the solid state suggest that the application of ultrasound leads to a π stacking induced molecular aggregation resulting in field effect mobilities as high as 0.03 cm2 V−1 s−1. A multiphase morphology, comprising short quasi‐ordered and larger, ordered nanofibrils embedded in a disordered amorphous phase is formed as a result of irradiation for at least 1 min. Two distinct regions of charge transport are identified, characterized by an initial sharp increase in the field effect mobility by two orders of magnitude due to an increase in crystallinity up to the percolation limit, followed by a gradual saturation where the mobility becomes independent of the thin film microstructure.
Copper‐Catalyzed Aromatic Trifluoromethylation via Group Transfer from Fluoral Derivatives
Authors: Kondo Hideaki , Oishi Masahiro , Fujikawa Kenichi , Amii Hideki
Published: May 2011

Starting from a readily available fluoral derivative, catalytic aromatic trifluoromethylation has been successfully achieved. A small amount of copper(I) iodide‐phenanthroline complex catalyzed the cross‐coupling reactions of aryl/heteroaryl iodides with the O‐silylated hemiaminal of fluoral (trifluoroacetaldehyde) to provide trifluoromethylated arenes in moderate to high yields.
A New Class of Heterogeneous Platinum Catalysts for the Chemoselective Hydrogenation of Nitroarenes
Authors: Pandarus Valerica , Ciriminna Rosaria , Béland François , Pagliaro Mario
Published: May 2011

A new series of nanostructured platinum catalysts able to catalyze the selective reduction of nitroarenes has been developed. The materials, made of organosilica physically doped with nanostructured platinum(0), are stable and efficient. Reactions in general proceed with high yield and often go to completion, while the catalysts can be reused in further reaction runs. This establishes a new class of relevant solid catalysts for synthetic organic chemistry named SiliaCat Platinum‐Hydrogel.
Regioselective Addition of Organometallic Reagents to 2‐(1‐Alkynyl)‐2‐alken‐1‐ones for an Efficient Synthesis of Substituted 1,2‐Allenyl Ketones
Authors: Yu Xiuzhao , Zhang Junliang
Published: May 2011

Highly substituted 1,2‐allenyl ketones can be easily and efficiently prepared from organometallic reagents and readily available 2‐(1‐alkynyl)‐2‐alken‐1‐ones. The synthetic application of 1,2‐allenyl ketone products was also showcased by palladium‐catalyzed further transformation.
Syndio‐ and Isoselective Coordinative Chain Transfer Polymerization of Styrene Promoted by ansa‐Lanthanidocene/ Dialkylmagnesium Systems
Authors: Sarazin Yann , de Frémont Pierre , Annunziata Liana , Duc Michel , Carpentier Jean‐François
Published: May 2011

Combinations of the discrete neutral allyl ansa‐lanthanidocenes {Me2C(Cp)(Flu)}Nd[1,3‐ (SiMe3)2C3H3] and rac‐{Me2C(Ind)2}Y[1,3‐ (SiMe3)2C3H3] with di(n‐butyl)magnesium constitute efficient binary catalytic systems for the stereocontrolled coordinative chain transfer polymerization of styrene, yielding near‐perfect syndio‐ and isospecific polystyrenes, respectively, with high activities and productivities. By adjusting the amount of di(n‐butyl)magnesium, up to 200 polymer chains can be generated per lanthabide center, and good control of the molecular weight features enables the tailoring of low to medium molecular weight polymers.
A Novel Mode of Reactivity for Gold(I): The Decarboxylative Activation of (Hetero)Aromatic Carboxylic Acids
Authors: Cornella Josep , Rosillo‐Lopez Martin , Larrosa Igor
Published: May 2011

Gold(I) salts are found to mediate the decarboxylation of a variety of aromatic and heteroaromatic carboxylic acids at significatively lower temperatures (as low as 60 °C) than the currently used copper(I) (180–190 °C) and silver(I) (80–140 °C) systems. In contrast to silver(I)‐ and copper(I)‐mediated decarboxylations, the resulting aryl‐gold(I) complexes are stable towards protodemetallation and can be readily isolated.
Integrated High‐Efficiency Pt/Carbon Nanotube Arrays for PEM Fuel Cells
Authors: Zhang Weimin , Minett Andrew I. , Gao Mei , Zhao Jie , Razal Joselito M. , Wallace Gordon G. , Romeo Tony , Chen Jun
Published: May 2011

A facile strategy to deposit Pt nanoparticles with various metal‐loading densities on vertically aligned carbon nanotube (ACNT) arrays as electrocatalysts for proton exchange membrane (PEM) fuel cells is described. The deposition is achieved by electrostatic adsorption of the Pt precursor on the positively charged polyelectrolyte functionalized ACNT arrays and subsequent reduction by L‐ascorbic acid. The application of the aligned electrocatalysts in fuel cells is realized by transferring from a quartz substrate to nafion membrane using a hot‐press procedure to fabricate the membrane electrode assembly (MEA). It is shown that the MEA with vertically aligned structured electrocatalysts provides better Pt utilization than that with Pt on conventional carbon nanotubes or carbon black, resulting in higher fuel cell performance.
Functional and Evolutionary significance of the recruitment and firing patterns of the jaw adductors during chewing in verreaux's sifaka (Propithecus verreauxi)
Authors: Hylander William L. , Vinyard Christopher J. , Wall Christine E. , Williams Susan H. , Johnson Kirk R.
Published: May 2011

Jaw‐muscle electromyographic (EMG) patterns indicate that compared with thick‐tailed galagos and ring‐tailed lemurs, anthropoids recruit more relative EMG from their balancing‐side deep masseter, and that this muscle peaks late in the power stroke. These recruitment and firing patterns in anthropoids are thought to cause the mandibular symphysis to wishbone (lateral transverse bending), resulting in relatively high symphyseal stresses. We test the hypothesis that living strepsirrhines with robust, partially fused symphyses have muscle recruitment and firing patterns more similar to anthropoids, unlike those strepsirrhines with highly mobile unfused symphyses. Electromyographic (EMG) activity of the superficial and deep masseter, anterior and posterior temporalis, and medial pterygoid muscles were recorded in four dentally adult Verreaux's sifakas (Propithecus verreauxi). As predicted, we find that sifaka motor patterns are more similar to anthropoids. For example, among sifakas, recruitment levels of the balancing‐side (b‐s) deep masseter are high, and the b‐s deep masseter fires late during the power stroke. As adult sifakas often exhibit nearly complete symphyseal fusion, these data support the hypothesis that the evolution of symphyseal fusion in primates is functionally linked to wishboning. Furthermore, these data provide compelling evidence for the convergent evolution of the wishboning motor patterns in anthropoids and sifakas. Am J Phys Anthropol 2011. © 2011 Wiley‐Liss, Inc.
Forward dynamic simulation of bipedal walking in the Japanese macaque: Investigation of causal relationships among limb kinematics, speed, and energetics of bipedal locomotion in a nonhuman primate
Authors: Ogihara Naomichi , Aoi Shinya , Sugimoto Yasuhiro , Tsuchiya Kazuo , Nakatsukasa Masato
Published: May 2011

Japanese macaques that have been trained for monkey performances exhibit a remarkable ability to walk bipedally. In this study, we dynamically reconstructed bipedal walking of the Japanese macaque to investigate causal relationships among limb kinematics, speed, and energetics, with a view to understanding the mechanisms underlying the evolution of human bipedalism. We constructed a two‐dimensional macaque musculoskeletal model consisting of nine rigid links and eight principal muscles. To generate locomotion, we used a trajectory‐tracking control law, the reference trajectories of which were obtained experimentally. Using this framework, we evaluated the effects of changes in cycle duration and gait kinematics on locomotor efficiency. The energetic cost of locomotion was estimated based on the calculation of mechanical energy generated by muscles. Our results demonstrated that the mass‐specific metabolic cost of transport decreased as speed increased in bipedal walking of the Japanese macaque. Furthermore, the cost of transport in bipedal walking was reduced when vertical displacement of the hip joint was virtually modified in the simulation to be more humanlike. Human vertical fluctuations in the body's center of mass actually contributed to energy savings via an inverted pendulum mechanism. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Lichtmikroskopie mit Doughnut‐Moden: ein Konzept zur Detektion, Charakterisierung und Manipulation einzelner Nanoobjekte
Authors: Züchner Tina , Failla Antonio Virgilio , Meixner Alfred J.
Published: May 2011

Lasermoden mit ringförmigem Strahlprofil, die zumeist als Doughnut‐Moden (DMs) bezeichnet werden, finden Anwendung in unterschiedlichen Forschungsbereichen wie den Bio‐ und Materialwissenschaften oder der Einzelmolekülmikroskopie und ‐spektroskopie. Der Hauptgrund für die wachsende Bedeutung der DMs liegt darin, dass in letzter Zeit die Techniken zur Herstellung dieser Moden mit hoher Präzision verfeinert oder wiederentdeckt wurden. Obwohl ihr Potential bisher noch nicht vollkommen ausgeschöpft wird, ermöglichen die speziellen Polarisationseigenschaften der DMs eine Vielzahl von Anwendungen. So tragen sie dazu bei, unser grundlegendes Verständnis der optischen Eigenschaften einzelner emittierender Spezies wie Moleküle, Nanopartikel oder Quantenpunkte zu vervollständigen und erlauben Einblick in die dreidimensionale Dipol‐ oder Partikelorientierung im Raum. Durch ihre vollständig verschwindende Intensität im Zentrum des Fokus eignen sich einige DMs auch für die stimulierte Emissionslöschung in der Fluoreszenzmikroskopie. Aus demselben Grund hat man sie auch für die Verwendung in optischen Fallen und Pinzetten vorgeschlagen.
SUMO meets meiosis: An encounter at the synaptonemal complex
Authors: Watts Felicity Z. , Hoffmann Eva
Published: May 2011

Recent discoveries have identified the small ubiquitin‐like modifier (SUMO) as the potential ‘missing link’ that could explain how the synaptonemal complex (SC) is formed during meiosis. The SC is important for a variety of chromosome interactions during meiosis and appears ladder‐like. It is formed when ‘axes’ of the two homologous chromosomes become connected by the deposition of transverse filaments, forming the steps of the ladder. Although several components of axial and transverse elements have been identified, how the two are connected to form the SC has remained an enigma. Recent discoveries suggest that SUMO modification underlies protein‐protein interactions within the SC of budding yeast. The versatility of SUMO in regulating protein‐protein interactions adds an exciting new dimension to our understanding of the SC and suggests that SCs are not homogenous structures throughout the nucleus. We propose that this heterogeneity may allow differential regulation of chromosome structure and function.