bluuebunny/crossref_metadata_2025 huggingface dataset:
Suicidal Ideation and Behaviours after Traumatic Brain Injury: A Systematic Review
Authors: Bahraini Nazanin H. , Simpson Grahame K. , Brenner Lisa A. , Hoffberg Adam S. , Schneider Alexandra L.
Published: May 2013

Traumatic brain injury (TBI) is prevalent among many populations and existing data suggest that those with TBI are at increased risk for death by suicide. This systematic review serves as an update to a previous review, with the aim of evaluating the current state of evidence regarding prevalence and risk of suicide deaths, post-TBI suicidal ideation and suicide attempts, and treatments to reduce suicide-related outcomes among TBI survivors. Review procedures followed the PRISMA statement guidelines. In all, 1014 abstracts and 83 full-text articles were reviewed to identify 16 studies meeting inclusion criteria. Risk of bias for individual studies ranged from low to high, and very few studies were designed to examine a priori hypotheses related to suicide outcomes of interest. Overall, findings from this systematic review supported an increased risk of suicide among TBI survivors compared to those with no history of TBI. Evidence pertaining to suicidal thoughts and attempts was less clear, mainly due to heterogeneity of methodological quality across studies. One small randomised controlled trial was identified that targeted suicide prevention in TBI survivors. Further research is needed to identify the prevalence of post-TBI ideation and attempts, and to establish evidence-based suicide prevention practices among TBI survivors.
Posttraumatic Stress Disorder, Depression, and Alcohol and Tobacco Use in Public Health Workers After the 2004 Florida Hurricanes
Authors: Fullerton Carol S. , McKibben Jodi B.A. , Reissman Dori B. , Scharf Ted , Kowalski-Trakofler Kathleen M. , Shultz James M. , Ursano Robert J.
Published: May 2013

Objective

We examined the relationship of probable posttraumatic stress disorder (PTSD), probable depression, and increased alcohol and/or tobacco use to disaster exposure and work demand in Florida Department of Health workers after the 2004 hurricanes.

Methods

Participants (N = 2249) completed electronic questionnaires assessing PTSD, depression, alcohol and tobacco use, hurricane exposure, and work demand.

Results

Total mental and behavioral health burden (probable PTSD, probable depression, increased alcohol and/or tobacco use) was 11%. More than 4% had probable PTSD, and 3.8% had probable depression. Among those with probable PTSD, 29.2% had increased alcohol use, and 50% had increased tobacco use. Among those with probable depression, 34% indicated increased alcohol use and 55.6% increased tobacco use. Workers with greater exposure were more likely to have probable PTSD and probable depression (ORs = 3.3 and 3.06, respectively). After adjusting for demographics and work demand, those with high exposure were more likely to have probable PTSD and probable depression (ORs = 3.21 and 3.13). Those with high exposure had increased alcohol and tobacco use (ORs = 3.01 and 3.40), and those with high work demand indicated increased alcohol and tobacco use (ORs = 1.98 and 2.10). High exposure and work demand predicted increased alcohol and tobacco use, after adjusting for demographics, work demand, and exposure.

Conclusions

Work-related disaster mental and behavioral health burden indicate the need for additional mental health interventions in the public health disaster workforce.(Disaster Med Public Health Preparedness. 2013;7:89-95)
On Additive invariants of actions of additive and multiplicative groups
Authors: Hu Wenchuan
Published: May 2013

Let X be an algebraic variety with an action of either the additive or multiplicative group. We calculate the additive invariants of X in terms of the additive invariants of the fixed point set, using a formula of Białynicki-Birula. The method is also generalized to calculate certain additive invariants for Chow varieties. As applications, we obtain results on the Hodge polynomial of Chow varieties in characteristic zero and the number of points for Chow varieties over finite fields. As applications, we obtain the l-adic Euler-Poincaré characteristic for the Chow varieties of certain projective varieties over a field of arbitrary characteristic. Moreover, we show that the virtual Hodge (p,0) and (0,q)-numbers of the Chow varieties and affine algebraic group varieties are zero for all p,q positive.
The Experience of Transitioning Two Adolescents With Asperger Syndrome in Academically Focused High Schools
Authors: Dixon Roselyn M. , Tanner Kathleen
Published: May 2013

Adolescents with Asperger syndrome (AS) are increasingly being placed in academically focused high schools. These students, although academically able, may not be coping with the wider classroom and social demands of transition to, and within, the high school environment. Schools are keen to enrol these students. However, there appears to be a gap between the rhetoric and the reality relating to the varying perceptions of key stakeholders. In this paper we present the results of a study of the perceptions of key stakeholders in the transition of two students with AS into two academically focused high schools. Eight participants were involved in semistructured, one-on-one interviews. Key stakeholders included executive teachers, classroom teachers, students and their caregivers. The results indicated that there were some differences in the teacher and caregiver perspectives across physical, academic and social areas of transition.
M. T. C. Cronin, 'The world last night', St Lucia: University of Queensland Press, 2012, ISBN 9 7807 0224 9518, 200 pp., A$24.95
Authors: Buckridge Patrick
Published: May 2013

M. T. C. Cronin, The world last night, St Lucia: University of Queensland Press, 2012, ISBN 9 7807 0224 9518, 200 pp., A$24.95
Environmental Politics and Policy in Queensland Under Labor, 1998–2012
Authors: Norton Paul
Published: May 2013

Environmental issues have been politically salient in Queensland throughout recent decades of Labor dominance. While in general Labor has benefited politically from being regarded as the ‘greener’ of the major parties, state Labor governments have also sometimes found environmental policy difficult to deal with. This is partly a reflection of the political passions that environmental and resource use conflicts can generate and is partly due to the pressures on environmental assets from population and economic growth in Queensland; primarily, however, it reflects the difficulty of reconciling environmental and sustainability policy goals with the historically dominant model of development in Queensland.
'My Teacher Told me "Toowoomba will Never Flood"'
Authors: McWilliam Kelly
Published: May 2013

Regional Queensland and social media are not standard bedfellows in studies of Australian media use. Yet regional community responses to recent natural disasters on Facebook in particular warrant further investigation. Indeed, while the increasing use of social media by government organisations during disasters and other crises is by now well documented, the comparative surge in community uses — and particularly regional community uses — has received considerably less attention. This article is broadly interested in regional Queensland uses of Facebook during the 2011 Queensland floods, specifically the ‘Toowoomba & Darling Downs Flood Photos & Info Page’ (https://www.facebook.com/TmbaLockyerFloods?fref=ts 10 January 2011). Drawing on an interview with the page's creator, I consider both the speed and apparent efficacy of the page as a tool of grassroots (or unofficial) crisis communication, partly compared with its most obvious official counterpart, the Toowoomba Regional Council's Facebook page. Ultimately, I argue that the ‘Toowoomba & Darling Downs Flood Photos & Info Page’ offers an emphatically more useful model of social media-based crisis communication from which others might draw.
NEGOTIATING OTTOMANISM IN TIMES OF WAR: JERUSALEM DURING WORLD WAR I THROUGH THE EYES OF A LOCAL MUSLIM RESIDENT
Authors: Jacobson Abigail
Published: May 2013

Through a microanalysis of a diary written by Ihsan Tourjman during World War I, this article explores how the Arab–Ottoman elite in Jerusalem experienced and viewed the war and perceived their own position within the Ottoman Empire. It focuses on the ways multilayered levels of identity were negotiated and debated following internal and external changes taking place at the time. The diary serves as a unique and valuable testimony that sheds light on life in Jerusalem at a critical period in the city's (and region's) history. Through close reading of this diary and other sources, this essay investigates how economic and social crises affected city residents and scrutinizes how political changes, as well as Ottoman policies and treatment of the local population, affected how individuals placed themselves within the context of the empire.
Effects of catechin polyphenols and preparations from the plant–parasitic nematode Heterodera glycines on protease activity and behaviour in three nematode species
Authors: Masler E.P.
Published: May 2013

Protease activities in preparations from the plant-parasitic nematodes Heterodera glycines and Meloidogyneincognita and the free-living nematode Panagrellus redivivus were inhibited by exposure to a series of eight catechin polyphenol analogues, (+)-catechin, ( − )-epicatechin (EC), ( − )-gallocatechin (GC), ( − )-epigallocatechin (EGC), ( − )-catechin gallate (CG), ( − )-gallocatechin gallate (GCG), ( − )-epicatechin gallate (ECG) and ( − )-epigallocatechin gallate (EGCG) (1 mm each), and by a preparation from H. glycines cysts. General protease activity detected with the FRET-peptide substrate QXL520-KSAYMRF-K(5-FAM)a and proteasome chymotrypsin-like (CTL) activity detected with succinyl-LLVY-AMC were each inhibited significantly more (P< 0.05) by the gallated form of the polyphenol than by the corresponding non-gallated form. Species differences in response to inhibition across all analogues were revealed with the CTL substrate, but CG was a consistently potent inhibitor across all three species and with each substrate. A heat-stable component (CE) from H. glycines cysts inhibited M. incognita CTL activity by 92.07 ± 0.68%, significantly less (P< 0.05) in H. glycines (52.86 ± 2.77%), and by only 17.24 ± 0.55% (P< 0.05) in P. redivivus preparations. CTL activity was, however, inhibited more than 60% in all preparations by the proteasome-specific inhibitor MG-132. Hatching of M. incognita infective juveniles exposed to 1 mm CG, ECG, GCG or EGCG was reduced by 83.88 ± 4.26%, 69.98 ± 9.14%, 94.93 ± 1.71% and 87.93 ± 2.89%, respectively, while hatching of H. glycines was reduced less than 25% by each analogue. CE had no effect on nematode hatch, but did cause a 60% reduction in mobility of H. glycines infective juveniles exposed overnight to CE in vitro, which was more (P< 0.05) than the reduction of M. incognita infective juvenile mobility (20%).
Ultra-intense attosecond pulses emitted from laser wakefields in non-uniform plasmas
Authors: Liu Y. , Li F.Y. , Zeng M. , Chen M. , Sheng Z.M.
Published: May 2013

A scheme of generating ultra-intense attosecond pulses in ultra-relativistic laser interaction with under-dense plasmas is proposed. The attosecond pulse emission is caused by an oscillating transverse current sheet formed by an electron density spike composed of trapped electrons in the laser wakefield and the residual transverse momentum of electrons left behind the laser pulse when its front is strongly modulated. As soon as the attosecond pulse emerges, it tends to feed back to further enhance the transverse electron momentum and the transverse current. Consequently, the attosecond pulse is enhanced and developed into a few cycles later until the density spike is depleted out due to the pump laser depletion. To control the formation of the transverse current sheet, a non-uniform plasma slab with an up-ramp density profile in front of a uniform region is adopted, which enables one to obtain attosecond pulses with higher amplitudes than that in a uniform plasma slab.
The Old English Benedictine Rule: writing for women and men
Authors: Jayatilaka Rohini
Published: May 2013

The Regula S. Benedicti was known and used in early Anglo-Saxon England, but
it was not until the mid-tenth-century Benedictine reform that the RSB became
established as the supreme and exclusive rule governing the monasteries of
England. The tenth-century monastic reform movement, undertaken by
Dunstan, Æthelwold and Oswald during the reign of Edgar (959–75), sought
to revitalize monasticism in England which, according to the standards of
these reformers, had ceased to exist during the ninth century. They took as a
basis for restoring monastic life the RSB, which was regarded by them as the
main embodiment of the essential principles of western monasticism, and in
this capacity it was established as the primary document governing English
monastic life. By elevating the status of the RSB as the central text of monastic
practice in England and the basis of a uniform way of life the reformers
raised for themselves the problem of ensuring that the RSB would be understood
in detail by all monks, nuns and novices, whatever their background.
Evidence of various attempts to make the text accessible, both at the linguistic
level and at the level of substance, survives in manuscripts dating from the
mid-tenth and eleventh centuries; the most important of these attempts is a
vernacular translation of the RSB.
An overview of search strategies in distributed environments
Authors: Del Val E. , Rebollo M. , Botti V.
Published: May 2013

Distributed systems are populated by a large number of heterogeneous entities that join and leave the systems dynamically. These entities act as clients and providers and interact with each other in order to get a resource or to achieve a goal. To facilitate the collaboration between entities, the system should provide mechanisms to manage the information about which entities or resources are available in the system at a certain moment, as well as how to locate them in an efficient way. However, this is not an easy task in open and dynamic environments where there are changes in the available resources and global information is not always available. In this paper, we present a comprehensive vision of search in distributed environments. This review not only considers the approaches of the peer-to-peer area, but also the approaches from three more areas: service-oriented environments, multi-agent systems, and complex networks. In these areas, the search for resources, services, or entities plays a key role for the proper performance of the systems built on them. The aim of this analysis is to compare approaches from these areas taking into account the underlying system structure and the algorithms or strategies that participate in the search process.
Selected applications of Rietveld-XRD analysis for raw materials of the aluminum industry
Authors: Feret Frank R.
Published: May 2013

In the last few decades, X-ray diffraction (XRD) systems have been paramount and irreplaceable in controlling bauxite exploration, as well as Bayer and reduction processes. XRD quantitative phase analysis in the aluminum industry witnessed a steady deployment of the Rietveld method, which at present progressively replaces existing methodologies in research and plant laboratories. Rietveld analysis not only helped to surpass traditional XRD calibration methods, it also opened the door for new applications previously not possible. The use of the Rietveld method to characterize selected materials unique to the aluminum industry, such as bauxite, red mud, and alumina is demonstrated and discussed. This paper also presents how synchrotron-based diffractograms obtained for bauxite and red mud samples allowed a much better understanding of mineralogical representation, and made it possible to leverage their Rietveld quantification. Despite clear advantages, the Rietveld method also has limitations that are revealed. For alumina phase quantification, a dedicated Rietveld analytical program was built with structure data for eight alumina mineralogical phases: alpha, beta (β-Al2O3 = Na2O•11Al2O3), delta, gamma (2), kappa, sigma, and theta. The paper gives unique examples of phase quantification in aluminas of various origins and phase composition.
Sisterhood in prosodic branching
Authors: Myrberg Sara
Published: May 2013

This article discusses the syntax–prosody interface, drawing on evidence from Stockholm Swedish. It is shown that a Swedish main clause containing an embedded clause has three prosodic correlates, two of which are non-isomorphic to the syntactic bracketing. However, two coordinated clauses have only one – isomorphic – prosodic correlate. Optimality-theoretic constraints (Prince & Smolensky 1993) are used to derive this variation. A new markedness constraint, EqualSisters, is argued to be responsible for a preference for flat prosodic structures. This constraint requires that sister nodes in prosodic structure belong to the same prosodic category, and therefore sometimes conflicts withmatchconstraints, which call for syntax–prosody correspondence (Selkirk 2009, 2011). When high-ranked, EqualSistersforces syntax–prosody non-isomorphism if the input syntactic structure contains embedding, whereas full isomorphism is predicted in coordinated structures. The previously suggested markedness constraints Non-recursivityand Exhaustivity(Selkirk 1996) cannot replace EqualSisters, and in the present account are rendered redundant.
On the semantics of noun compounds
Authors: SZPAKOWICZ STAN , BOND FRANCIS , NAKOV PRESLAV , KIM SU NAM
Published: May 2013

The noun compound – a sequence of nouns which functions as a single noun – is very common in English texts. No language processing system should ignore expressions like steel soup pot cover if it wants to be serious about such high-end applications of computational linguistics as question answering, information extraction, text summarization, machine translation – the list goes on. Processing noun compounds, however, is far from trouble-free. For one thing, they can be bracketed in various ways: is it steel soup, steel pot, or steel cover? Then there are relations inside a compound, annoyingly not signalled by any words: does potcontainsoup or is it for cookingsoup? These and many other research challenges are the subject of this special issue.
Severe malnutrition among children under the age of 5 years admitted to a rural district hospital in southern Mozambique
Authors: Nhampossa Tacilta , Sigaúque Betuel , Machevo Sónia , Macete Eusebio , Alonso Pedro , Bassat Quique , Menéndez Clara , Fumadó Victoria
Published: May 2013

Objective

To describe the burden, clinical characteristics and prognostic factors of severe malnutrition in children under the age of 5 years.

Design

Retrospective study of hospital-based data systematically collected from January 2001 to December 2010.

Setting

Rural Mozambican district hospital.

Subjects

All children aged <5 years admitted with severe malnutrition.

Results

During the 10-year long study surveillance, 274 813 children belonging to Manhiça's Demographic Surveillance System were seen at out-patient clinics, almost half of whom (47 %) presented with some indication of malnutrition and 6 % (17 188/274 813) with severe malnutrition. Of these, only 15 % (2522/17 188) were eventually admitted. Case fatality rate of severe malnutrition was 7 % (162/2274). Bacteraemia, hypoglycaemia, oral candidiasis, prostration, oedema, pallor and acute diarrhoea were independently associated with an increased risk of in-hospital mortality, while malaria parasitaemia and breast-feeding were independently associated with a lower risk of a poor outcome. Overall minimum community-based incidence rate was 15 cases per 1000 child-years at risk and children aged 12–23 months had the highest incidence.

Conclusions

Severe malnutrition among admitted children in this Mozambican setting was common but frequently went undetected, despite being associated with a high risk of death. Measures to improve its recognition by clinicians responsible for the first evaluation of patients at the out-patient level are urgently needed so as to improve their likelihood of survival. Together with this, the rapid management of complications such as hypoglycaemia and concomitant co-infections such as bacteraemia, acute diarrhoea, oral candidiasis and HIV/AIDS may contribute to reverse the intolerable toll that malnutrition poses in the health of children in rural African settings.
SYSTEMS OF ISLANDS WITH CONTINUOUS HEIGHT FUNCTIONS
Authors: LENGVÁRSZKY ZSOLT
Published: May 2013

We investigate island systems with continuous height functions and strongly laminar systems which are laminar systems containing sets with disjoint boundaries. In the discrete case, we show that for a maximal rectangular system of islands$ \mathcal{H} $on an$m$by$n$rectangular grid we have$\lceil \min (m, n)/ 4\rceil \leq \vert \mathcal{H} \vert \leq \lceil m/ 2\rceil \lceil n/ 2\rceil $. In the continuous case we show that under some conditions maximal strongly laminar systems$ \mathcal{H} $have cardinality${\aleph }_{0} $or${2}^{{\aleph }_{0} } $and present examples with$\vert \mathcal{H} \vert = {\aleph }_{0} $.
A review of vascular disrupting agents as a concomitant anti-tumour modality with radiation
Authors: Tran William Tyler , El Kaffas Ahmed , Al-Mahrouki Azza , Gillies Carol , Czarnota Gregory Jan
Published: May 2013

Background

Tumour vasculature plays an important role in the development, maintenance and sustainability of a tumour. Endothelial cells which are recruited into the tumour stroma facilitate the formation of essential blood vessels that deliver nutrients and oxygen to tumour cells. A growing body of research is showing that there are synergistic anti-tumour effects when anti-vascular agents are combined with radiation. More recent reports have described favourable radiation response as a function of vascular targeting and blood vessel breakdown, primarily through interactions of radiation with vascular endothelial cells. Vascular disrupting agents are being utilised in several forms that include molecular targeting, biophysical assault and biological interference.

Purpose

In the present review, we examine current advances in anti-vascular agents to enhance tumour response when combined with radiation therapy.

Methods

A comprehensive literature search was conducted on the US National Library of Medicine, National Institutes of Health (PubMed) using the following search keywords: vascular disrupting agents, radiation sensitisation, anti-angiogenic therapy, anti-vascular therapy, radiation therapy.

Conclusion

Current research suggests the applicability of vascular disrupting agents as an effective radiation sensitisation agent. Pre-clinical and clinical trials have been well developed to form the theoretical framework to apply this powerful modality to the treatment of cancer.
White Paper: Landscape on Technical and Conceptual Requirements and Competence Framework in Drug/Disease Modeling and Simulation
Authors: Vlasakakis G , Comets E , Keunecke A , Gueorguieva I , Magni P , Terranova N , Della Pasqua O , de Lange EC , Kloft C
Published: May 2013

Pharmaceutical sciences experts and regulators acknowledge that pharmaceutical development as well as drug usage requires more than scientific advancements to cope with current attrition rates/therapeutic failures. Drug disease modeling and simulation (DDM&S) creates a paradigm to enable an integrated and higher‐level understanding of drugs, (diseased)systems, and their interactions (systems pharmacology) through mathematical/statistical models (pharmacometrics)1—hence facilitating decision making during drug development and therapeutic usage of medicines. To identify gaps and challenges in DDM&S, an inventory of skills and competencies currently available in academia, industry, and clinical practice was obtained through survey. The survey outcomes revealed benefits, weaknesses, and hurdles for the implementation of DDM&S. In addition, the survey indicated that no consensus exists about the knowledge, skills, and attributes required to perform DDM&S activities effectively. Hence, a landscape of technical and conceptual requirements for DDM&S was identified and serves as a basis for developing a framework of competencies to guide future education and training in DDM&S.

CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e40; doi:10.1038/psp.2013.16; advance online publication 1 May 2013
Steady state conductance in a double quantum dot array: The nonequilibrium equation-of-motion Green function approach
Authors: Levy Tal J. , Rabani Eran
Published: May 2013

We study steady state transport through a double quantum dot array using the equation-of-motion approach to the nonequilibrium Green functions formalism. This popular technique relies on uncontrolled approximations to obtain a closure for a hierarchy of equations; however, its accuracy is questioned. We focus on 4 different closures, 2 of which were previously proposed in the context of the single quantum dot system (Anderson impurity model) and were extended to the double quantum dot array, and develop 2 new closures. Results for the differential conductance are compared to those attained by a master equation approach known to be accurate for weak system-leads couplings and high temperatures. While all 4 closures provide an accurate description of the Coulomb blockade and other transport properties in the single quantum dot case, they differ in the case of the double quantum dot array, where only one of the developed closures provides satisfactory results. This is rationalized by comparing the poles of the Green functions to the exact many-particle energy differences for the isolate system. Our analysis provides means to extend the equation-of-motion technique to more elaborate models of large bridge systems with strong electronic interactions.
Coherent neutron scattering and collective dynamics on mesoscale
Authors: Novikov V. N. , Schweizer K. S. , Sokolov A. P.
Published: May 2013

By combining, and modestly extending, a variety of theoretical concepts for the dynamics of liquids in the supercooled regime, we formulate a simple analytic model for the temperature and wavevector dependent collective density fluctuation relaxation time that is measurable using coherent dynamic neutron scattering. Comparison with experiments on the ionic glass-forming liquid Ca–K–NO3 in the lightly supercooled regime suggests the model captures the key physics in both the local cage and mesoscopic regimes, including the unusual wavevector dependence of the collective structural relaxation time. The model is consistent with the idea that the decoupling between diffusion and viscosity is reflected in a different temperature dependence of the collective relaxation time at intermediate wavevectors and near the main (cage) peak of the static structure factor. More generally, our analysis provides support for the ideas that decoupling information and growing dynamic length scales can be at least qualitatively deduced by analyzing the collective relaxation time as a function of temperature and wavevector, and that there is a strong link between dynamic heterogeneity phenomena at the single and many particle level. Though very simple, the model can be applied to other systems, such as molecular liquids.
Probing dual mode emission of Eu3+ in garnet phosphor
Authors: Singh S. K. , Gi Lee Dong , Soo Yi Soung , Jang Kiwan , Shin Dong-Soo , Hyun Jeong Jung
Published: May 2013

Eu3+ doped and Eu3+, Yb3+ co-doped Gd3Ga5O12 phosphors have been developed by facile solid state reaction method which can be easily scaled-up in large quantity. The synthesis has been optimized to get a single phase material at 1300 °C. The phase and crystal parameters have been analyzed by using X-ray diffraction measurement. Photoluminescence excitation (monitored for the 5D0 → 7F1 transition of Eu3+) depicts that the active ion (Eu3+) can be excited through direct excitation into 4f band of Eu3+, through charge transfer band (Eu3+-O2−) excitation and also through the excitation into 8S7/2 → 6IJ intra f–f transition of Gd3+ ion, which significantly all together cover a broad excitation region in 200–420 nm. In addition, in the presence of Yb3+ ions, the emission is also achieved by near infrared excitation (976 nm), through a typical upconversion (UC) process. Thus, the material efficiently behaves as a dual mode emitting phosphor (emission is achieved both through normal fluorescence and through UC process). The conversion efficiency of silicon solar cells is only 15% of terrestrial solar energy for 200–400 nm region and also the sub-band gap energy (in infrared region) is lost as heat; therefore, this kind of dual mode phosphors may be used to overcome the above mentioned incomplete utilization of the solar spectrum and can open realm of new possibilities for energy harvesting.
Reconfigurable resistive switching devices based on individual tungsten trioxide nanowires
Authors: Guo Jie , Zhou Yong , Yuan Huajun , Zhao Ding , Yin Yanling , Hai Kuo , Peng Yuehua , Zhou Weichang , Tang Dongsheng
Published: May 2013

In the two-terminal Au/WO3 nanowire/Au electronic device with two Schottky barriers, drifting of oxygen vacancies under strong electric field induced by the bias voltage applied at short distance will result in the effective width of the reverse biased Schottky barrier decreasing,and then result in the memristive effect or resistive switching phenomenon. By unidirectional bias voltage sweeping, the Au/WO3Schottky contact can be turned gradually and reversibly into Ohmic contact, and then the two-terminal Au/WO3 nanowire/Au resistive switching device can be reconfigured gradually and reversibly from non-rectifying state to either a forward or reverse rectifying state.
Structures, stability, mechanical and electronic properties of α-boron andα*-boron
Authors: He Chaoyu , Zhong J. X.
Published: May 2013

The structures, stability, mechanical and electronic properties of α-boron and a promising metastable boron phase (α*-boron) have been studied by first-principles calculations. α-boron and α*-boron consist of equivalent icosahedra B12clusters in different connecting configurations of “3S-6D-3S” and “2S-6D-4S”, respectively. The total energy calculations show that α*-boron is less stable than α-boron but more favorable than the well-known β-boron and γ-boron at zero pressure. Both α-boron and α*-boron are confirmed dynamically and mechanically stable. The mechanical and electronic properties of α-boron and α*-boron indicate that they are potential superhard semiconducting phases of element boron.
Temporal and spatial mating-system variation in fragmented populations of Banksia cuneata, a rare bird-pollinated long-lived plant
Authors: Coates David J. , Williams Matthew R. , Madden Sally
Published: May 2013

Plant mating systems can vary significantly in both space and time, influencing a range of demographic and genetic processes critical for the persistence of plant populations. Spatial and temporal mating-system variations were investigated in Banksia cuneata (A. S. George), a rare bird-pollinated shrub occurring in a highly fragmented landscape. Substantial variation in the mating system was observed, with the magnitude of temporal variation within a population often as high as the level of spatial variation among populations within a season. A significant reduction in outcrossing rates and increased temporal variation in both outcrossing rates and correlated paternity were observed in disturbed populations. Doubling of the paternal neighbourhood and a trend to increased outcrossing rate was found after augmentation of a disturbed population where population size was increased from 57 to 214 adult plants. A large increase in the fixation index for seeds compared with adults was observed in all populations, with the magnitude of the difference showing temporal and spatial uniformity. We suggest that temporal mating-system variation warrants increased consideration, not only in assessing the effects of habitat fragmentation on plant populations, but also in the design and establishment of successful translocation, augmentation and restoration programs.
Global view of the evolution and diversity of metazoan neuropeptide signaling
Authors: Jékely Gáspár
Published: May 2013

Neuropeptides are signaling molecules that commonly act via G protein-coupled receptors (GPCRs) and are generated in neurons by proneuropeptide (pNP) cleavage. Present in both cnidarians and bilaterians, neuropeptides represent an ancient and widespread mode of neuronal communication. Due to the inherent difficulties of analyzing highly diverse and repetitive pNPs, the relationships among different families are often elusive. Using similarity-based clustering and sensitive similarity searches, I obtained a global view of metazoan pNP diversity and evolution. Clustering revealed a large and diffuse network of sequences connected by significant sequence similarity encompassing one-quarter of all families. pNPs belonging to this cluster were also identified in the early-branching neuronless animal
Trichoplax adhaerens
. Clustering of neuropeptide GPCRs identified several orthology groups and allowed the reconstruction of the phyletic distribution of receptor families. GPCR phyletic distribution closely paralleled that of pNPs, indicating extensive conservation and long-term coevolution of receptor–ligand pairs. Receptor orthology and intermediate sequences also revealed the homology of pNPs so far considered unrelated, including allatotropin and orexin. These findings, together with the identification of deuterostome achatin and luqin and protostome opioid pNPs, extended the neuropeptide complement of the urbilaterian. Several pNPs were also identified from the hemichordate
Saccoglossus kowalevskii
and the cephalochordate
Branchiostoma floridae,
elucidating pNP evolution in deuterostomes. Receptor–ligand conservation also allowed ligand predictions for many uncharacterized GPCRs from nonmodel species. The reconstruction of the neuropeptide-signaling repertoire at deep nodes of the animal phylogeny allowed the formulation of a testable scenario of the evolution of animal neuroendocrine systems.
Dual-color superresolution microscopy reveals nanoscale organization of mechanosensory podosomes
Authors: van den Dries K. , Schwartz S. L. , Byars J. , Meddens M.B.M. , Bolomini-Vittori M. , Lidke D. S. , Figdor C. G. , Lidke K. A. , Cambi A.
Published: May 2013

Podosomes are multimolecular mechanosensory assemblies that coordinate mesenchymal migration of tissue-resident dendritic cells. They have a protrusive actin core and an adhesive ring of integrins and adaptor proteins, such as talin and vinculin. We recently demonstrated that core actin oscillations correlate with intensity fluctuations of vinculin but not talin, suggesting different molecular rearrangements for these components. Detailed information on the mutual localization of core and ring components at the nanoscale is lacking. By dual-color direct stochastic optical reconstruction microscopy, we for the first time determined the nanoscale organization of individual podosomes and their spatial arrangement within large clusters formed at the cell–substrate interface. Superresolution imaging of three ring components with respect to actin revealed that the cores are interconnected and linked to the ventral membrane by radiating actin filaments. In core-free areas, αMβ2 integrin and talin islets are homogeneously distributed, whereas vinculin preferentially localizes proximal to the core and along the radiating actin filaments. Podosome clusters appear as self-organized contact areas, where mechanical cues might be efficiently transduced and redistributed. Our findings call for a reevaluation of the current “core–ring” model and provide a novel structural framework for further understanding the collective behavior of podosome clusters.
High prevalence of VIM-4 and NDM-1 metallo-β-lactamase among carbapenem-resistant Enterobacteriaceae
Authors: Jamal Wafaa , Rotimi Vincent O. , Albert M. John , Khodakhast Fatima , Nordmann Patrice , Poirel Laurent
Published: May 2013

The purpose of this study was to identify the mechanisms leading to carbapenem resistance among multidrug-resistant Enterobacteriaceae isolates recovered from hospitalized patients with nosocomial infections in Mubarak Al Kabeer Hospital, Kuwait. Fourteen carbapenem-resistant Enterobacteriaceae isolates were obtained from inpatients in different wards and intensive care units between April 2009 and February 2011. Antibiotic susceptibilities were determined using the E-test method. Genes encoding β-lactamases were characterized by specific PCR amplification, sequencing and conjugation assays. All isolates were identified as metallo-β-lactamase (MBL) producers using phenotypic and molecular methods. Eleven of the 14 isolates produced VIM-4 (six Klebsiella pneumoniae, three Escherichia coli, one Enterobacter cloacae and one Klebsiella oxytoca). Three K. pneumoniae isolates produced the MBL NDM-1 and co-produced the plasmid-encoded AmpC CMY-4. The VIM-4-producing isolates co-produced extended-spectrum β-lactamases including CTX-M-15 and some SHV derivatives. The VIM-4 gene was not transferable by conjugation studies of six selected strains. We demonstrated here the emergence of VIM-4- and NDM-1-producing isolates in the largest teaching hospital in Kuwait.
Non-structural protein P6 encoded by rice black-streaked dwarf virus is recruited to viral inclusion bodies by binding to the viroplasm matrix protein P9-1
Authors: Sun Liying , Xie Li , Andika Ida Bagus , Tan Zilong , Chen Jianping
Published: May 2013

Like other members of the family Reoviridae, rice black-streaked dwarf virus (RBSDV, genus Fijivirus) is thought to replicate and assemble within cytoplasmic viral inclusion bodies, commonly called viroplasms. RBSDV P9-1 is the key protein for the formation of viroplasms, but little is known about the other proteins of the viroplasm or the molecular interactions amongst its components. RBSDV non-structural proteins were screened for their association with P9-1 using a co-immunoprecipitation assay. Only P6 was found to directly interact with P9-1, an interaction that was confirmed by bimolecular fluorescence complementation assay in Spodoptera frugiperda (Sf9) cells. Immunoelectron microscopy showed that P6 and P9-1 co-localized in electron-dense inclusion bodies, indicating that P6 is a constituent of the viroplasm. In addition, non-structural protein P5 also localized to viroplasms and interacted with P6. In Sf9 cells, P6 was diffusely distributed throughout the cytoplasm when expressed alone, but localized to inclusions when co-expressed with P9-1, suggesting that P6 is recruited to viral inclusion bodies by binding to P9-1. P5 localized to the inclusions formed by P9-1 when co-expressed with P6 but did not when P6 was absent, suggesting that P5 is recruited to viroplasms by binding to P6. This study provides a model by which viral non-structural proteins are recruited to RBSDV viroplasms.
A broadly applicable high-throughput screening strategy identifies new regulators of Dlg4 (Psd-95) alternative splicing
Authors: Zheng Sika , Damoiseaux Robert , Chen Liang , Black Douglas L.
Published: May 2013

Most mammalian genes produce multiple mRNA isoforms derived from alternative pre-mRNA splicing, with each alternative exon controlled by a complex network of regulatory factors. The identification of these regulators can be laborious and is usually carried out one factor at a time. We have developed a broadly applicable high-throughput screening method that simultaneously identifies multiple positive and negative regulators of a particular exon. Two minigene reporters were constructed: One produces green fluorescent protein (GFP) from the mRNA including an exon, and red fluorescent protein (RFP) from the mRNA lacking the exon; the other switches these fluorescent products of exon inclusion and exclusion. Combining results from these two reporters eliminates many false positives and greatly enriches for true splicing regulators. After extensive optimization of this method, we performed a gain-of-function screen of 15,779 cDNA clones and identified 40 genes affecting exon 18 of Discs large homolog 4 (Dlg4; also known as post-synaptic density protein 95 [Psd-95]). We confirmed that 28 of the 34 recoverable clones alter reporter splicing in RT-PCR assays. Remarkably, 18 of the identified genes encode splicing factors or RNA binding proteins, including PTBP1, a previously identified regulator of this exon. Loss-of-function experiments examining endogenous Dlg4 transcripts validated the effects of five of eight genes tested in independent cell lines, and two genes were further confirmed to regulate Dlg4 splicing in primary neurons. These results identify multiple new regulators of Dlg4 splicing, and validate an approach to isolating splicing regulators for almost any cassette exon from libraries of cDNAs, shRNAs, or small molecules.
Quantitative proteomic analysis reveals concurrent RNA–protein interactions and identifies new RNA-binding proteins in Saccharomyces cerevisiae
Authors: Klass Daniel M. , Scheibe Marion , Butter Falk , Hogan Gregory J. , Mann Matthias , Brown Patrick O.
Published: May 2013

A growing body of evidence supports the existence of an extensive network of RNA-binding proteins (RBPs) whose combinatorial binding affects the post-transcriptional fate of every mRNA in the cell—yet we still do not have a complete understanding of which proteins bind to mRNA, which of these bind concurrently, and when and where in the cell they bind. We describe here a method to identify the proteins that bind to RNA concurrently with an RBP of interest, using quantitative mass spectrometry combined with RNase treatment of affinity-purified RNA–protein complexes. We applied this method to the known RBPs Pab1, Nab2, and Puf3. Our method significantly enriched for known RBPs and is a clear improvement upon previous approaches in yeast. Our data reveal that some reported protein–protein interactions may instead reflect simultaneous binding to shared RNA targets. We also discovered more than 100 candidate RBPs, and we independently confirmed that 77% (23/30) bind directly to RNA. The previously recognized functions of the confirmed novel RBPs were remarkably diverse, and we mapped the RNA-binding region of one of these proteins, the transcriptional coactivator Mbf1, to a region distinct from its DNA-binding domain. Our results also provided new insights into the roles of Nab2 and Puf3 in post-transcriptional regulation by identifying other RBPs that bind simultaneously to the same mRNAs. While existing methods can identify sets of RBPs that interact with common RNA targets, our approach can determine which of those interactions are concurrent—a crucial distinction for understanding post-transcriptional regulation.
Social insect genomes exhibit dramatic evolution in gene composition and regulation while preserving regulatory features linked to sociality
Authors: Simola Daniel F. , Wissler Lothar , Donahue Greg , Waterhouse Robert M. , Helmkampf Martin , Roux Julien , Nygaard Sanne , Glastad Karl M. , Hagen Darren E. , Viljakainen Lumi , Reese Justin T. , Hunt Brendan G. , Graur Dan , Elhaik Eran , Kriventseva Evgenia V. , Wen Jiayu , Parker Brian J. , Cash Elizabeth , Privman Eyal , Childers Christopher P. , Muñoz-Torres Monica C. , Boomsma Jacobus J. , Bornberg-Bauer Erich , Currie Cameron R. , Elsik Christine G. , Suen Garret , Goodisman Michael A.D. , Keller Laurent , Liebig Jürgen , Rawls Alan , Reinberg Danny , Smith Chris D. , Smith Chris R. , Tsutsui Neil , Wurm Yannick , Zdobnov Evgeny M. , Berger Shelley L. , Gadau Jürgen
Published: May 2013

Genomes of eusocial insects code for dramatic examples of phenotypic plasticity and social organization. We compared the genomes of seven ants, the honeybee, and various solitary insects to examine whether eusocial lineages share distinct features of genomic organization. Each ant lineage contains ∼4000 novel genes, but only 64 of these genes are conserved among all seven ants. Many gene families have been expanded in ants, notably those involved in chemical communication (e.g., desaturases and odorant receptors). Alignment of the ant genomes revealed reduced purifying selection compared withDrosophilawithout significantly reduced synteny. Correspondingly, ant genomes exhibit dramatic divergence of noncoding regulatory elements; however, extant conserved regions are enriched for novel noncoding RNAs and transcription factor–binding sites. Comparison of orthologous gene promoters between eusocial and solitary species revealed significant regulatory evolution in bothcis(e.g.,Creb) andtrans(e.g.,fork head) for nearly 2000 genes, many of which exhibit phenotypic plasticity. Our results emphasize that genomic changes can occur remarkably fast in ants, because two recently diverged leaf-cutter ant species exhibit faster accumulation of species-specific genes and greater divergence in regulatory elements compared with other ants orDrosophila. Thus, while the “socio-genomes” of ants and the honeybee are broadly characterized by a pervasive pattern of divergence in gene composition and regulation, they preserve lineage-specific regulatory features linked to eusociality. We propose that changes in gene regulation played a key role in the origins of insect eusociality, whereas changes in gene composition were more relevant for lineage-specific eusocial adaptations.
Responses of Nannochloropsis oceanica IMET1 to Long-Term Nitrogen Starvation and Recovery
Authors: Dong Hong-Po , Williams Ernest , Wang Da-zhi , Xie Zhang-Xian , Hsia Ru-ching , Jenck Alizée , Halden Rolf , Li Jing , Chen Feng , Place Allen R.
Published: May 2013

The Nannochloropsis genus contains oleaginous microalgae that have served as model systems for developing renewable biodiesel. Recent genomic and transcriptomic studies on Nannochloropsis species have provided insights into the regulation of lipid production in response to nitrogen stress. Previous studies have focused on the responses of Nannochloropsis species to short-term nitrogen stress, but the effect of long-term nitrogen deprivation remains largely unknown. In this study, physiological and proteomic approaches were combined to understand the mechanisms by which Nannochloropsis oceanica IMET1 is able to endure long-term nitrate deprivation and its ability to recover homeostasis when nitrogen is amended. Changes of the proteome during chronic nitrogen starvation espoused the physiological changes observed, and there was a general trend toward recycling nitrogen and storage of lipids. This was evidenced by a global down-regulation of protein expression, a retained expression of proteins involved in glycolysis and the synthesis of fatty acids, as well as an up-regulation of enzymes used in nitrogen scavenging and protein turnover. Also, lipid accumulation and autophagy of plastids may play a key role in maintaining cell vitality. Following the addition of nitrogen, there were proteomic changes and metabolic changes observed within 24 h, which resulted in a return of the culture to steady state within 4 d. These results demonstrate the ability of N. oceanica IMET1 to recover from long periods of nitrate deprivation without apparent detriment to the culture and provide proteomic markers for genetic modification.