bluuebunny/crossref_metadata_2025 huggingface dataset:
Donor–acceptor semiconducting polymers for organic solar cells
Authors: Kularatne Ruvini S. , Magurudeniya Harsha D. , Sista Prakash , Biewer Michael C. , Stefan Mihaela C.
Published: November 2012

This review describes the synthesis and photovoltaic performance of donor–acceptor (D–A) semiconducting polymers that have been reported during the last decade. 9,9‐Dialkyl‐2,7‐ fluorene, 2,7‐carbazole, cyclopenta[2,1‐b:3,4‐b′]dithiophene, dithieno[3,2‐b:2′,3′‐d]silole, dithieno[3,2‐b:2′,3′‐d]pyrrole, benzo[1,2‐b:4,5‐b′]dithiophene, benzo[1,2 b:4,5 b′]difuran building blocks, and their D–A copolymers are described in this review. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Facile synthesis of dendrimers combining aza‐Michael addition with Thiol‐yne click chemistry
Authors: Shen Yong , Ma Yinan , Li Zhibo
Published: November 2012

We report a highly efficient approach to prepare dendrimers by taking advantage of the orthogonal characteristic of aza‐Michael addition and thiol‐yne reactions. A fifth generation dendrimer was synthesized within five steps without protection/activation procedures. The reactions proceed under benign conditions without byproducts, and the target products can be easily purified via extraction or precipitation without chromatography. The structure of each generation dendrimer was characterized using NMR spectroscopy, size exclusion chromatography, and mass spectrometry. The obtained dendrimers can have peripheral amine or alkyne groups. We demonstrated that these groups can be used for selective and specific conjugation with various functional groups. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Legal Perspective on Development Policies for Sustainability of Water in Malaysia
Authors: Khalid Rasyikah Md , Rahman Suhaimi Ab , Mokhtar Mazlin bin
Published: November 2012

Malaysia aims to be a developed state by 2020. Various programs and policies towards this have been promulgated and development is rapidly arising as a result. Nevertheless, there is a vital need to balance development and sustainability of water resources in Malaysia. This is important as water demand is steadily increasing in the country's industrialized and highly populated cities. It is significant that water resources be managed efficiently and water conservation efforts such as rainwater harvesting be promoted across the country. This paper aims to examine development policies that may affect the sustainability of water resources and their implementation from the legal point of view. This doctrinal study involves analyses of related laws and development policies and their impact over the development process. The paper concludes that, although important laws and policies have been introduced, implementation has been hindered by lack of support from stakeholders and lack of integration between water agencies. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
Synthesis and Structural Characterization of Bis(tetrahydro­pyran)calcium Bis[bis(trimethylsilyl)amide]
Authors: Younis Fadi M. , Görls Helmar , Krieck Sven , Westerhausen Matthias
Published: November 2012

Transmetalation of Sn[N(SiMe3)2]2 with calcium granules in tetrahydropyran (thp) yields colorless [(thp)2Ca{N(SiMe3)2}2] (1) which is soluble in common organic solvents. The calcium center is in a distorted tetrahedral environment with Ca–N and Ca–O bond lengths of 231.08(11) and 240.23(9) pm, respectively. The molecular structure is dominated by steric factors leading to a NCaN bond angle of 119.43(6)°.
Comparing caudal and intravenous ketamine for supplementation of analgesia after Salter innominate osteotomy
Authors: Amiri Hamid Reza , Espandar Ramin , Sanatkar Mehdi
Published: November 2012

Purpose

Previous studies claim that caudal administration of ketamine causes effective analgesia. The aim of this study was to assess the clinical effectiveness of ketamine after caudal or intravascular administration in pediatric patients that underwent orthopedic surgery to distinguish between local and systemic analgesia.

Methods

After the induction of general anesthesia, 36 patients, aged 18 months to 10 years, assigned to undergo orthopedic surgery, received a caudal injection of bupivacaine and were randomly blinded into two groups: one group received 1 mg/kg S(+)-ketamine as the caudal group and the other group received 1 mg/kg S(+)-ketamine as the intravascular group. Postsurgical measurements included the effectiveness of postsurgical analgesia, which was assessed by using the observational pain scale (OPS), duration of analgesia, sedation score, and hemodynamic and respiratory monitoring.

Results

The mean time to first analgesia was clearly longer in the caudal ketamine group (13.35 h) than in the intravenous ketamine (9.93 h) group ( P < 0.01). During the 24-h observation time, fewer children asked for additional analgesic drugs in the caudal group (8 of 18, 44.4 %) than in the intravenous group (12 of 18, 66.6 %; P = 0.01). The times to first micturation and spontaneous leg movements and the incidence of nausea and vomiting were similar in the two groups. The OPS and sedation scores after operation showed no obvious differences between the groups at any time.

Conclusion

Although caudal ketamine provides good postsurgical analgesia due to its potential neurotoxicity and only small clinical differences with intravenous ketamine, the administration of intravenous ketamine might be a reasonable option to potentially extend the postsurgical analgesic effect of the caudal administration of local anesthetics in children undergoing Salter osteotomy.
Shear-strengthening of reinforced & prestressed concrete beams using FRP: Part II — Experimental investigation
Authors: Kang Thomas H. -K. , Ary Moustapha Ibrahim
Published: November 2012

The main objectives of this research were to experimentally evaluate the impact of Carbon Fiber-Reinforced Polymers (CFRP) amount and strip spacing on the shear behavior of prestressed concrete (PC) beams and to evaluate the applicability of existing analytical models of Fiber-Reinforced Polymer (FRP) shear capacity to PC beams shear-strengthened with CFRP. The Ushaped CFRP strips with different spacing were applied externally to the test specimens in order to observe the overall behavio r of the prestressed concrete I-beams and the mode of failure of the applied CFRP strips. Results obtained from the experimental program showed that the application of CFRP strips to prestressed concrete I-beams did in fact enhance the overall behavior of the specimens. The strengthened specimens responded with an increase in ductility and in shear capacity. However, it should be noted that the CFRP strips were not effective at all at spacing greater than half the effective depth of the specimen and that fracture of the strips was the dominant failure mechanism of CFRP. Further research is needed to confirm the conclusion derived from the experimental program.
Calmodulin activates neuronal nitric oxide synthase by enabling transitions between conformational states
Authors: Salerno John C. , Ray Krishanu , Poulos Thomas , Li Huiying , Ghosh Dipak K.
Published: November 2012

We recently showed that inducible nitric oxide synthase conformational intermediates can be resolved via FMN fluorescence lifetimes. Here we show that neuronal NOS activation by calmodulin removes constraints favoring a closed ‘input state’, increasing occupation of other states and facilitating conformational transitions. The 90 ps FMN input state lifetime distinguishes it from ∼4 ns ‘open’ states in which FMN does not interact strongly with other groups, or 0.9 ns output states in which FMN interacts with ferriheme. Enablement of the conformational cycle is an important paradigm for control in nNOS and related enzymes, and may extend to other control modalities.
Crystal structures of dye‐decolorizing peroxidase with ascorbic acid and 2,6‐dimethoxyphenol
Authors: Yoshida Toru , Tsuge Hideaki , Hisabori Toru , Sugano Yasushi
Published: November 2012

The structure of dye‐decolorizing peroxidase (DyP)‐type peroxidase differs from that of other peroxidase families, indicating that DyP‐type peroxidases have a different reaction mechanism. We have determined the crystal structures of DyP with ascorbic acid and 2,6‐dimethoxyphenol at 1.5 and 1.4 Å, respectively. The common binding site for both substrates was located at the entrance of the second cavity leading from the DyP molecular surface to heme. This resulted in a hydrogen bond network connection between each substrate and the heme distal side. This network consisted of water molecules occupying the second cavity, heme 6‐propionate, Arg329, and Asn313. This network is consistent with the proton transfer pathway from substrate to DyP.
Injury and Illness in Mountain Bicycle Stage Racing: Experience from the Trans-Sylvania Mountain Bike Epic Race
Authors: McGrath Todd M. , Yehl Michael A.
Published: November 2012

Objective

The popularity of mountain bicycle (MTB) riding has increased significantly since its inception in the 1970s, as have injuries from MTB riding. As MTB stage racing is a relatively new segment of MTB racing, the purpose of this study was to evaluate the injury and illness patterns associated with MTB stage racing to assist future medical providers in covering events.

Methods

The Trans-Sylvania Mountain Bike Epic Race consisted of 7 stages. An onsite medical team of physicians, nurses, and paramedics provided medical coverage. The providers logged each medical encounter on a medical form. The log included the location where the treatment was provided (on course, at the finish or after the race), a description of the injury/illness, treatment that was rendered, the supplies needed for treatment, and the disposition of the patient (continue, withdraw but continue the next day, withdraw, or transfer to the hospital).

Results

A total of 52 athletes competed in the inaugural edition of the race. There were 30 separate medical encounters, with a total of 34 injuries/illnesses. Of these, 22 (65%) were classified as injury, and 12 (35%) were classified as illness. Four athletes withdrew from the race, 1 from injury and 3 from illness. Skin and soft tissue injuries/illnesses were the most prevalent.

Conclusions

Injury and illness patterns of MTB stage racing are similar to those of other wilderness sporting events and prior data on MTB-related injuries. Minor skin, soft tissue, and orthopedic injuries are the most common. Illness accounts for the majority of withdrawals.
La citoyenneté canadienne dans la presse écrite anglo-canadienne et franco-québécoise : convergence ou divergence?
Authors: Winter Elke , Sauvageau Marie-Michèle
Published: November 2012

Résumé.La publication d'un nouveau guide d'étude destiné aux immigrants qui souhaitent acquérir la citoyenneté canadienne en 2009 constitue la première réforme de cet ouvrage depuis sa parution en 1995. Notre analyse se penche sur les réactions dans la presse écrite anglo-canadienne et franco-québécoise entourant cette nouvelle publication. Contrairement au postulat d'un « choc des identités » au Canada, nos résultats démontrent qu'une alliance implicite s'est forgée entre « les deux solitudes» canadiennes dans leur compréhension de la citoyenneté, alors qu'est reconnue, dans les deux groupes de quotidiens, l'importance de protéger les « acquis » de la société canadienne contre les croyances et les pratiques de l'« Autre » non-civilisé. Toutefois, la prudence est de mise: la convergence des représentations médiatiques de la citoyenneté canadienne, renvoie-t-elle vraiment à une identité collective partagée au Québec et au Canada?

Abstract.The release of a new study guide for immigrants aiming to become Canadian citizens in 2009 was the first major reform of this document since its inception in 1995. This paper examines the coverage of the Anglo-Canadian and Franco-Québécois press surrounding the new citizenship guide. Rather than supporting the widely accepted thesis that Canada is marked by a « collision of identities », our study suggests the emergence of an implicit alliance between the two Canadian “solitudes” with respect to their understanding of citizenship. In particular, the two groups of newspapers agree upon the necessity to protect « acquired gains » of Canadian society against the beliefs and practices of an uncivilized « Other ». Nevertheless, we should not jump to conclusions: does the convergence of media representations of Canadian citizenship really reflect the emergence of a shared collective identity in Quebec and Canada?
HISTORY, MEMORY, AND THE ENGLISH REFORMATION
Authors: WALSHAM ALEXANDRA
Published: November 2012

This article is a revised and expanded version of my inaugural lecture as Professor of Modern History at the University of Cambridge, delivered on 20 Oct. 2011. It explores how the religious upheavals of the sixteenth and seventeenth centuries reshaped perceptions of the past, stimulated shifts in historical method, and transformed the culture of memory, before turning to the interrelated question of when and why contemporaries began to remember the English Reformation as a decisive juncture and critical turning point in history. Investigating the interaction between personal recollection and social memory, it traces the manner in which remembrance of the events of the 1530s, 1540s, and 1550s evolved and splintered between 1530 and 1700. A further theme is the role of religious and intellectual developments in the early modern period in forging prevailing models of historical periodization and teleological paradigms of interpretation.
FATHERHOOD, PROVIDING, AND ATTACHMENT IN LATE VICTORIAN AND EDWARDIAN WORKING-CLASS FAMILIES
Authors: STRANGE JULIE-MARIE
Published: November 2012

Histories of the late Victorian working-class family focus overwhelmingly on mothers. When men feature in family dynamics, it is within the context of their obligation to provide. Despite the familiarity of this model of family life, it is problematic, not least because it is partial. Written from a women's history perspective, such analyses have inevitably, and understandably, focused on the ‘dark side’ of breadwinning and privileged women's experiences as wives and mothers. Further, they have tended to make husbands synonymous with fathers. Drawing on working-class autobiography, this article revisits the cliché of the ‘good provider’ to suggest that children could invest the normative paternal obligation to provide with intimate and individual meaning, reimagining breadwinning as an act of devotion that distinguished particular father–child relationships within a context of more general working-class values. It does not suggest that women were not oppressed by the breadwinner ideal, or that attachment to mothers and fathers was the same. Rather, it calls for recognition of the fluidity of a sexual division of affective labour whereby, in memory at least, fathers' obligation to provide could be deeply embedded within an understanding of the emotional dynamics of everyday life.
SOUTH ASIAN HISTORIES OF CITIZENSHIP, 1946–1970
Authors: CHATTERJI JOYA
Published: November 2012

After partition, minorities in South Asia emerged as a distinct legal category of citizens who were not fully protected by the states within which they lived. The power of South Asia's nation-states over their ‘minority-citizens’ far exceeds their sovereignty over ordinary citizens, and the capacity of ‘minority-citizens’ to resist this power was broken, this article will show, by a series of draconian executive actions. But ‘minority citizenship’ was not simply a product of ‘bureaucratic rationality’, as some have suggested, or even of ‘governmentality’. On the contrary, it was produced by complex, often violent, interactions between government and a range of non-state actors, who forced their own ideas of nationality, justice, and entitlement on to the statute books. Citizenship in South Asia thus proves to have a complex parenthood, with ‘civil’ and ‘political’ more entangled, and mutually constituted, than some theorists would have us believe. India and Pakistan continued to be bound together by migrants and migration even as their discursive claims seemed to pull them ever further apart.
ACCESS TO CONTRACEPTIVE METHODS AND PREVALENCE OF USE
Authors: ROSS JOHN , HARDEE KAREN
Published: November 2012

Survey data on contraceptive use for about 80 countries are related to measures of contraceptive access, by method, from 1999 to 2009. Cross-tabulation and correlational methods are employed, with geographic comparisons and time trends. Total prevalence of use for five modern contraceptive methods correlates well to a variety of access measures. Greater access is also accompanied by a better balance among methods for both access and use. Sub-Saharan African countries show similar patterns though at lower levels. Improved access to multiple methods is consistently associated with higher levels of contraceptive use.
The first record of fossil penguins from East Antarctica
Authors: Jadwiszczak Piotr , Krajewski Krzysztof P. , Pushina Zinaida , Tatur Andrzej , Zieliński Grzegorz
Published: November 2012

This paper presents the first fossil penguin from East Antarctica, and the only one known south of the Antarctic Circle. It is represented by two well-preserved elements of the wing skeleton, humerus and radius, obviously assignable to the extant genus Spheniscus. They were found in the glaciomarine succession of the Fisher Bench Formation (Fisher Massif, Prince Charles Mountains, Mac. Robertson Land), which was dated using Strontium Isotope Stratigraphy to be Late Miocene in age (10.2 Ma). They are only slightly younger than the oldest remains undoubtedly attributable to this taxon. The X-ray diffraction and Fourier Transform Infrared Spectroscopy indicate diagenetic alteration of the original bone bioapatite under dominantly marine conditions. The Late Miocene was a period of ice margin retreat and marine incursion into the Lambert embayment that followed Middle Miocene cooling of the Antarctic climate. The fossils strongly suggest that variable climatic and environmental conditions in East Antarctica may have been an important factor in the evolution of penguins there during the Neogene.
Reliability and validity of the Attitudes to Ageing Questionnaire (AAQ) in older people in Spain
Authors: Lucas-Carrasco Ramona , Laidlaw Ken , Gómez-Benito Juana , Power Michael J.
Published: November 2012

Background: As ageing is a personal experience, an attitude to ageing questionnaire is essential for capturing the most realistic appraisal of this important stage of life. Our aim was to study the psychometric properties of the Attitudes to Ageing Questionnaire (AAQ) in a sample of Spanish older people.

Methods: A total of 242 participants aged 60 years and older were recruited from community centers, primary care centers, and family associations for the mentally ill and dementia. In addition to the AAQ, participants provided information on demographics, self-perception of health, comorbidity, health status (SF-12), depressive symptoms (GDS-30), and quality of life (WHOQOL-BREF and WHOQOL-OLD). Analysis was performed using standard psychometric techniques with SPSS v15.0.

Results: No floor and ceiling effects were found, and missing data were low. The internal consistency measured by Cronbach's alpha for AAQ subscales were 0.59, 0.70, and 0.73. Exploratory Factor Analysis produced a three-factors solution accounting for 34% of the variance. A priori expected associations were found between some AAQ subscales with WHOQOL-BREF domains, with WHOQOL-OLD, SF-12, and the GDS-30 indicating good construct validity. In general, AAQ subscales differentiated between participants with lower and higher levels of education, and between a priori defined groups of older people (non-depressed vs. depressed; those with higher vs. lower physical comorbidities, and non-carers vs. carers).

Conclusions: The Spanish version of the AAQ questionnaire showed acceptable psychometric properties in a convenience sample of Spanish older people. It is a useful measure of attitude for use with older people in social and clinical services.
Evidence for potential and inductive convection during intense geomagnetic events using normalized superposed epoch analysis
Authors: Katus Roxanne M. , Liemohn Michael W. , Gallagher Dennis L. , Ridley Aaron , Zou Shasha
Published: November 2012

The relative contribution of storm‐time ring current development by convection driven by either potential or inductive electric fields has remained an unresolved question in geospace research. Studies have been published supporting each side of this debate, including views that ring current buildup is entirely one or the other. This study presents new insights into the relative roles of these storm main phase processes. We perform a superposed epoch study of 97 intense (DstMin < –100 nT) and 91 moderate (–50 nT > DstMin > –100 nT) storms using OMNI solar wind and ground‐based data. Instead of using a single reference time for the superpositioning of the events, we choose four reference times and expand or contract each phase of every event to the average length of this phase, creating a normalized timeline for the superposed epoch analysis. Using the bootstrap method, we statistically demonstrate that timeline normalization results in better reproduction of average storm dynamics than conventional methods. Examination of the Dst reveals an inflection point in the intense storm group consistent with two‐step main phase development, which is supported by results for the southward interplanetary magnetic field and various ground‐based magnetic indices. This two‐step main‐phase process is not seen in the moderate storm timeline and data sets. It is determined that the first step of Dst development is due to potential convective drift, during which an initial ring current is formed. The negative feedback of this hot ion population begins to limit further ring current growth. The second step of the main phase, however, is found to be a more even mix of potential and inductive convection. It is hypothesized that this is necessary to achieve intense storm Dst levels because the substorm dipolarizations are effective at breaking through the negative feedback barrier of the existing inner magnetospheric hot ion pressure peak.
Ion gyroharmonic structures in stimulated radiation during second electron gyroharmonic heating: 1. Theory
Authors: Samimi A. , Scales W. A. , Fu H. , Bernhardt P. A. , Briczinski S. J. , McCarrick M. J.
Published: November 2012

Stimulated electromagnetic emissions (SEEs) may provide important diagnostic information about space plasma composition, energetics, and dynamics during active experiments in which ground‐based high‐powered radio waves are transmitted into the ionosphere. The nonlinear plasma processes producing this secondary radiation are not well understood particularly for some recent observations where the transmitter (pump) frequency is near the second harmonic of the electron gyrofrequency. New, more comprehensive, experimental observations of spectral features within 1 kHz of the pump wave frequency are reported here to begin more careful comparisons of the experimental observations and a possible theoretical underpinning, which is also provided. The experimental observations typically show two distinct types of secondary radiation spectra, which are (a) discrete narrowband harmonic spectral structures ordered by the ion gyrofrequency and (b) broadband spectral structure with center frequency near 500 Hz and similar spectral bandwidth. A theoretical model is provided that interprets these spectral features as resulting from parametric decay instabilities in which the pump field ultimately decays into high‐frequency upper hybrid/electron Bernstein and low‐frequency neutralized ion Bernstein and/or obliquely propagating ion acoustic waves at the upper hybrid interaction altitude. Detailed calculations of the threshold level, growth rate, unstable wave number, and frequency bandwidth of the instabilities are provided for comparisons with experimental observations. An assessment of the effect of the critical instability parameters are provided including pump electric field strength, proximity of the pump frequency to the electron gyrofrequency and pump electric field geometry. The model shows quite reasonable agreement with the experimental observations. Further discussions are provided of connections with past observed SEE spectral features and potential new diagnostic information provided by these newly categorized spectra.
The effect of the dynamic surface bareness on dust source function, emission, and distribution
Authors: Kim Dongchul , Chin Mian , Bian Huisheng , Tan Qian , Brown Molly E. , Zheng Tai , You Renjie , Diehl Tomas , Ginoux Paul , Kucsera Tom
Published: November 2012

In this study we report the development of a time dependency of global dust source and its impact on dust simulation in the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model. We determine the surface bareness using the 8 km normalized difference vegetation index (NDVI) observed from the advanced very high resolution radiometer satellite. The results are used to analyze the temporal variations of surface bareness in 22 global dust source regions. One half of these regions can be considered permanent dust source regions where NDVI is always less than 0.15, while the other half shows substantial seasonality of NDVI. This NDVI‐based surface bareness map is then used, along with the soil and topographic characteristics, to construct a dynamic dust source function for simulating dust emissions with the GOCART model. We divide the 22 dust source regions into three groups of (I) permanent desert, (II) seasonally changing bareness that regulates dust emissions, and (III) seasonally changing bareness that has little effect on dust emission. Compared with the GOCART results with the previously employed static dust source function, the simulation with the new dynamic source function shows significant improvements in category II regions. Even though the global improvement of the aerosol optical depth (AOD) is rather small when compared with satellite and ground‐based remote sensing observations, we found a clear and significant effect of the new dust source on seasonal variation of dust emission and dust optical depth near the source regions. Globally, we have found that the permanent bare land contributes to 88% of the total dust emission, whereas the grassland and cultivated crops land contribute to about 12%. Our results suggest the potential of using NDVI over a vegetated area to link the dust emission with land cover and land use change for air quality and climate change studies.
A robust, two‐parameter method for the extraction of drainage networks from high‐resolution digital elevation models (DEMs): Evaluation using synthetic and real‐world DEMs
Authors: Pelletier Jon D.
Published: November 2012

Key Points

Drainage network extraction methods should not rely on contributing area

Drainage networks can be extracted from digital data using just two parameters

The method works well on different landscapes using the same parameter values
Battle of extreme value distributions: A global survey on extreme daily rainfall
Authors: Papalexiou Simon Michael , Koutsoyiannis Demetris
Published: November 2012

Key Points

We analyze the annual maximum daily rainfall in 15137 sites all over the world

We find that Frechet extreme value distribution prevails over the Gumbel one

We construct a global map of the shape parameter of the distribution
Pre-exposure to drought increases the resistance of tropical forest soil bacterial communities to extended drought
Authors: Bouskill Nicholas J , Lim Hsiao Chien , Borglin Sharon , Salve Rohit , Wood Tana E , Silver Whendee L , Brodie Eoin L
Published: November 2012

Global climate models project a decrease in the magnitude of precipitation in tropical regions. Changes in rainfall patterns have important implications for the moisture content and redox status of tropical soils, yet little is known about how these changes may affect microbial community structure. Specifically, does exposure to prior stress confer increased resistance to subsequent perturbation? Here we reduced the quantity of precipitation throughfall to tropical forest soils in the Luquillo Mountains, Puerto Rico. Treatments included newly established throughfall exclusion plots (de novo excluded), plots undergoing reduction for a second time (pre-excluded) and ambient control plots. Ten months of throughfall exclusion led to a small but statistically significant decline in soil water potential and bacterial populations clearly adapted to increased osmotic stress. Although the water potential decline was small and microbial biomass did not change, phylogenetic diversity in the de novo-excluded plots decreased by ∼40% compared with the control plots, yet pre-excluded plots showed no significant change. On the other hand, the relative abundances of bacterial taxa in both the de novo-excluded and pre-excluded plots changed significantly with throughfall exclusion compared with control plots. Changes in bacterial community structure could be explained by changes in soil pore water chemistry and suggested changes in soil redox. Soluble iron declined in treatment plots and was correlated with decreased soluble phosphorus concentrations, which may have significant implications for microbial productivity in these P-limited systems.
Current recommended levels of dietary lysine in finisher pig diets are sufficient to maximise the response to ractopamine over 28 days but are insufficient in the first 7 days
Authors: Rikard-Bell C. V. , Pluske J. R. , van Barneveld R. J. , Mullan B. P. , Edwards A. C. , Gannon N. J. , Henman D. J. , Dunshea F. R.
Published: November 2012

Dietary ractopamine increases lean tissue deposition and responses increase as dose is increased provided sufficient dietary lysine is supplied. In Australia, diets supplemented with ractopamine (RAC) are formulated with 0.56 g available lysine per MJ digestible energy. The present study was conducted to investigate the interactions between dietary RAC and lysine on growth and carcass characteristics in ad libitum fed (13.8 MJ/kg) boars and gilts. The study involved 108 individually penned pigs at 17 weeks of age (64.1 ± 0.57 kg) in a 2 by 2 by 3 factorial design, with the respective factors being sex (gilt or boar), dietary lysine (low and high, i.e. 0.56 or 0.65 g available lysine/MJ digestible energy, respectively) and dietary RAC (0, 5 or 20 mg/kg) for 28 days. Over the 28-day study duration, both lysine diets containing dietary RAC were sufficient to elicit a response in average daily gain (ADG) (+5.8%, P = 0.026) and carcass weight (3%, P = 0.045), but not in feed efficiency (FE) (P = 0.555). However, over the period of the first 7 days, there were interactions between the effects of RAC and lysine for FE (P = 0.025) and ADG (P = 0.023), with both traits being responsive only to dietary RAC containing the high lysine, which increased FE (+9.1%, P = 0.002) and ADG (+7.2%, P = 0.068). Dietary RAC improved FE in the latter stages of the study, namely Days 15–21 (+5.7%, P = 0.031) and Days 22–28 (+4.9%, P = 0.040). The high RAC diet reduced carcass P2 backfat (–16.5%, P < 0.001) and fat tissue deposition (–6.2%, P = 0.074) and high lysine tended to reduce fat tissue deposition (–13.3%, P = 0.072). A sex by lysine interaction (P = 0.043) was observed for lean tissue deposition at 28 days, such that only the high-lysine diet increased lean deposition in boars (+11%, P < 0.05) but not in gilts. Dietary RAC tended to increase lean deposition (+14.0%, P = 0.067) in the first 14 days; however, only the high RAC diet increased lean deposition (+9.6%, P < 0.05) over 28 days. In conclusion, the current recommended supplementation levels of lysine for commercial gilts and boars fed RAC may limit the response to dietary RAC if the feeding regime is for short durations and boars will not maximise their lean tissue deposition rates.
Merck Ad5/HIV induces broad innate immune activation that predicts CD8
+
T-cell responses but is attenuated by preexisting Ad5 immunity
Authors: Zak Daniel E. , Andersen-Nissen Erica , Peterson Eric R. , Sato Alicia , Hamilton M. Kristina , Borgerding Joleen , Krishnamurty Akshay T. , Chang Joanne T. , Adams Devin J. , Hensley Tiffany R. , Salter Alexander I. , Morgan Cecilia A. , Duerr Ann C. , De Rosa Stephen C. , Aderem Alan , McElrath M. Juliana
Published: November 2012

To better understand how innate immune responses to vaccination can lead to lasting protective immunity, we used a systems approach to define immune signatures in humans over 1 wk following MRKAd5/HIV vaccination that predicted subsequent HIV-specific T-cell responses. Within 24 h, striking increases in peripheral blood mononuclear cell gene expression associated with inflammation, IFN response, and myeloid cell trafficking occurred, and lymphocyte-specific transcripts decreased. These alterations were corroborated by marked serum inflammatory cytokine elevations and egress of circulating lymphocytes. Responses of vaccinees with preexisting adenovirus serotype 5 (Ad5) neutralizing antibodies were strongly attenuated, suggesting that enhanced HIV acquisition in Ad5-seropositive subgroups in the Step Study may relate to the lack of appropriate innate activation rather than to increased systemic immune activation. Importantly, patterns of chemoattractant cytokine responses at 24 h and alterations in 209 peripheral blood mononuclear cell transcripts at 72 h were predictive of subsequent induction and magnitude of HIV-specific CD8
+
T-cell responses. This systems approach provides a framework to compare innate responses induced by vectors, as shown here by contrasting the more rapid, robust response to MRKAd5/HIV with that to yellow fever vaccine. When applied iteratively, the findings may permit selection of HIV vaccine candidates eliciting innate immune response profiles more likely to drive HIV protective immunity.
Frequency modulation entrains slow neural oscillations and optimizes human listening behavior
Authors: Henry Molly J. , Obleser Jonas
Published: November 2012

The human ability to continuously track dynamic environmental stimuli, in particular speech, is proposed to profit from “entrainment” of endogenous neural oscillations, which involves phase reorganization such that “optimal” phase comes into line with temporally expected critical events, resulting in improved processing. The current experiment goes beyond previous work in this domain by addressing two thus far unanswered questions. First, how general is neural entrainment to environmental rhythms: Can neural oscillations be entrained by temporal dynamics of ongoing rhythmic stimuli without abrupt onsets? Second, does neural entrainment optimize performance of the perceptual system: Does human auditory perception benefit from neural phase reorganization? In a human electroencephalography study, listeners detected short gaps distributed uniformly with respect to the phase angle of a 3-Hz frequency-modulated stimulus. Listeners’ ability to detect gaps in the frequency-modulated sound was not uniformly distributed in time, but clustered in certain preferred phases of the modulation. Moreover, the optimal stimulus phase was individually determined by the neural delta oscillation entrained by the stimulus. Finally, delta phase predicted behavior better than stimulus phase or the event-related potential after the gap. This study demonstrates behavioral benefits of phase realignment in response to frequency-modulated auditory stimuli, overall suggesting that frequency fluctuations in natural environmental input provide a pacing signal for endogenous neural oscillations, thereby influencing perceptual processing.
Highly efficient full-length hepatitis C virus genotype 1 (strain TN) infectious culture system
Authors: Li Yi-Ping , Ramirez Santseharay , Jensen Sanne B. , Purcell Robert H. , Gottwein Judith M. , Bukh Jens
Published: November 2012

Chronic infection with hepatitis C virus (HCV) is an important cause of end stage liver disease worldwide. In the United States, most HCV-related disease is associated with genotype 1 infection, which remains difficult to treat. Drug and vaccine development was hampered by inability to culture patient isolates representing HCV genotypes 1–7 and subtypes; only a recombinant 2a genome (strain JFH1) spontaneously replicated in vitro. Recently, we identified three mutations F1464L/A1672S/D2979G (LSG) in the nonstructural (NS) proteins, essential for development of full-length HCV 2a (J6) and 2b (J8) culture systems in Huh7.5 cells. Here, we developed a highly efficient genotype 1a (strain TN) full-length culture system. We initially found that the LSG substitutions conferred viability to an intergenotypic recombinant composed of TN 5′ untranslated region (5′UTR)-NS5A and JFH1 NS5B-3′UTR; recovered viruses acquired two adaptive mutations located in NS3 and NS4B. Introduction of these changes into a replication-deficient TN full-length genome, harboring LSG, permitted efficient HCV production. Additional identified NS4B and NS5B mutations fully adapted the TN full-length virus. Thus, a TN genome with 8 changes (designated TN cell-culture derived, TNcc) replicated efficiently and released infectious particles of ∼5 log
10
focus-forming units per mL; passaged TNcc did not require additional changes. IFN-α and directly acting antivirals targeting the HCV protease, NS5A, and NS5B, each inhibited full-length TN infection dose-dependently. Given the unique importance of genotype 1 for pathogenesis, this infectious 1a culture system represents an important advance in HCV research. The approach used and the mutations identified might permit culture development for other HCV isolates, thus facilitating vaccine development and personalized treatment.
Small heat shock proteins target mutant cystic fibrosis transmembrane conductance regulator for degradation via a small ubiquitin-like modifier–dependent pathway
Authors: Ahner Annette , Gong Xiaoyan , Schmidt Bela Z. , Peters Kathryn W. , Rabeh Wael M. , Thibodeau Patrick H. , Lukacs Gergely L. , Frizzell Raymond A.
Published: November 2012

Small heat shock proteins (sHsps) bind destabilized proteins during cell stress and disease, but their physiological functions are less clear. We evaluated the impact of Hsp27, an sHsp expressed in airway epithelial cells, on the common protein misfolding mutant that is responsible for most cystic fibrosis. F508del cystic fibrosis transmembrane conductance regulator (CFTR), a well-studied protein that is subject to cytosolic quality control, selectively associated with Hsp27, whose overexpression preferentially targeted mutant CFTR to proteasomal degradation. Hsp27 interacted physically with Ubc9, the small ubiquitin-like modifier (SUMO) E2 conjugating enzyme, implying that F508del SUMOylation leads to its sHsp-mediated degradation. Enhancing or disabling the SUMO pathway increased or blocked Hsp27’s ability to degrade mutant CFTR. Hsp27 promoted selective SUMOylation of F508del NBD1 in vitro and of full-length F508del CFTR in vivo, which preferred endogenous SUMO-2/3 paralogues that form poly-chains. The SUMO-targeted ubiquitin ligase (STUbL) RNF4 recognizes poly-SUMO chains to facilitate nuclear protein degradation. RNF4 overexpression elicited F508del degradation, whereas Hsp27 knockdown blocked RNF4’s impact on mutant CFTR. Similarly, the ability of Hsp27 to degrade F508del CFTR was lost during overexpression of dominant-negative RNF4. These findings link sHsp-mediated F508del CFTR degradation to its SUMOylation and to STUbL-mediated targeting to the ubiquitin–proteasome system and thereby implicate this pathway in the disposal of an integral membrane protein.
Scatology, Chopped Liver, and the Last Supper: Daniel Zimmermann's Holocaust Novel
L'Anus du monde
Authors: Mole Gary D.
Published: November 2012

Intellectual trends in the study of scatology have all tended to agree on the subversive character of scatological rhetoric and representation for social, political, institutional, religious, literary, and artistic discourses. This article offers a brief overview of these trends in order to situate an aspect of Holocaust narrative that has attracted far less attention than other polemical subjects such as the relationship between fiction, history, and memory, or sexuality and violence. The study takes as its focal point the critically neglected novel
L'Anus du monde
(1996) by the French writer Daniel Zimmermann, in which the scatological, though constituting an excremental assault on the reader's literary and moral sensibilities, functions against its usually subversive intent. By tracing the novel's anti-hero on his journey from Drancy to Auschwitz and Treblinka, Zimmermann links the scatological to the themes of gastronomy and anthropophagy, leading ineluctably to the novel's deeply unsettling conclusion, which in fact has less to do with the scatological than with the Christological overtones of sacrifice and redemption.
Initial boundary value problem for the focusing nonlinear Schrödinger equation with Robin boundary condition: half-line approach
Authors: Its Alexander , Shepelsky Dmitry
Published: November 2012

We consider the initial boundary value problem for the focusing nonlinear Schrödinger equation in the quarter plane
x
>0,
t
>0 in the case of decaying initial data (for
t
=0, as

) and the Robin boundary condition at
x
=0. We revisit the approach based on the simultaneous spectral analysis of the Lax pair equations and show that the method can be implemented without any a priori assumptions on the long-time behaviour of the boundary values.
Finite auxetic deformations of plane tessellations
Authors: Mitschke Holger , Robins Vanessa , Mecke Klaus , Schröder-Turk Gerd E.
Published: November 2012

We systematically analyse the mechanical deformation behaviour, in particular Poisson's ratio, of floppy bar-and-joint frameworks based on periodic tessellations of the plane. For frameworks with more than one deformation mode, crystallographic symmetry constraints or minimization of an angular vertex energy functional are used to lift this ambiguity. Our analysis allows for systematic searches for auxetic mechanisms in archives of tessellations; applied to the class of one- or two-uniform tessellations by regular or star polygons, we find two auxetic structures of hexagonal symmetry and demonstrate that several other tessellations become auxetic when retaining symmetries during the deformation, in some cases with large negative Poisson ratios
ν
<−1 for a specific lattice direction. We often find a transition to negative Poisson ratios at finite deformations for several tessellations, even if the undeformed tessellation is infinitesimally non-auxetic. Our numerical scheme is based on a solution of the quadratic equations enforcing constant edge lengths by a Newton method, with periodicity enforced by boundary conditions.
Green's function for the Laplace–Beltrami operator on a toroidal surface
Authors: Green Christopher C. , Marshall Jonathan S.
Published: November 2012

Green's function for the Laplace–Beltrami operator on the surface of a three-dimensional ring torus is constructed. An integral ingredient of our approach is the stereographic projection of the torus surface onto a planar annulus. Our representation for Green's function is written in terms of the Schottky–Klein prime function associated with the annulus and the dilogarithm function. We also consider an application of our results to vortex dynamics on the surface of a torus.
CLOCK deubiquitylation by USP8 inhibits CLK/CYC transcription in Drosophila
Authors: Luo Weifei , Li Yue , Tang Chih-Hang Anthony , Abruzzi Katharine C. , Rodriguez Joseph , Pescatore Stefan , Rosbash Michael
Published: November 2012

A conserved transcriptional feedback loop underlies animal circadian rhythms. In Drosophila, the transcription factors CLOCK (CLK) and CYCLE (CYC) activate the transcription of direct target genes like period (per) and timeless (tim). They encode the proteins PER and TIM, respectively, which repress CLK/CYC activity. Previous work indicates that repression is due to a direct PER–CLK/CYC interaction as well as CLK/CYC phosphorylation. We describe here the role of ubiquitin-specific protease 8 (USP8) in circadian transcriptional repression as well as the importance of CLK ubiquitylation in CLK/CYC transcription activity. usp8 loss of function (RNAi) or expression of a dominant-negative form of the protein (USP8-DN) enhances CLK/CYC transcriptional activity and alters fly locomotor activity rhythms. Clock protein and mRNA molecular oscillations are virtually absent within circadian neurons of USP8-DN flies. Furthermore, CLK ubiquitylation cycles robustly in wild-type flies and peaks coincident with maximal CLK/CYC transcription. As USP8 interacts with CLK and expression of USP8-DN increases CLK ubiquitylation, the data indicate that USP8 deubiquitylates CLK, which down-regulates CLK/CYC transcriptional activity. Taken together with the facts that usp8 mRNA cycles and that its transcription is activated directly by CLK/CYC, USP8, like PER and TIM, contributes to the transcriptional feedback loop cycle that underlies circadian rhythms.
Cell cycle gene-specific control of transcription has a critical role in proliferation of primordial germ cells
Authors: Okamura Daiji , Maeda Ikuma , Taniguchi Hirofumi , Tokitake Yuko , Ikeda Makiko , Ozato Keiko , Mise Nathan , Abe Kuniya , Noce Toshiaki , Izpisua Belmonte Juan Carlos , Matsui Yasuhisa
Published: November 2012

Transcription elongation is stimulated by positive transcription elongation factor b (P-TEFb), for which activity is repressed in the 7SK small nuclear ribonucleoprotein (7SK snRNP) complex. We show here a critical role of 7SK snRNP in growth control of primordial germ cells (PGCs). The expression of p15INK4b, a cyclin-dependent kinase inhibitor (CDKI) gene, in PGCs is selectively activated by P-TEFb and its recruiting molecule, Brd4, when the amount of active P-TEFb is increased due to reduction of the 7SK snRNP, and PGCs consequently undergo growth arrest. These results indicate that CDKI gene-specific control of transcription by 7SK snRNP plays a pivotal role in the maintenance of PGC proliferation.