bluuebunny/crossref_metadata_2025 huggingface dataset:
The chief, the youth and the plantation: communal politics in southern Nigeria
Authors: von Hellermann Pauline
Published: May 2010

In August 2006 the chief of Udo, a small town in Edo State, Nigeria, was deposed and the town taken over by the ‘youth’. This event presents the classic fall of a ‘big man’ who had lost support, but also involved long-standing chieftaincy rivalries, electoral competition in the run up to the 2007 elections, and conflict over a nearby oil palm and rubber plantation. Through an examination of Udo's crisis, this paper engages with three key questions concerning contemporary communal politics in southern Nigeria: the manifestations of patrimonial power and resistance to it; the meaning and role of ‘youth’; and the impact of expatriate capital.
Dust ion-acoustic solitary waves in a magnetized dusty electronegative plasma
Authors: ANOWAR M. G. M. , ASHRAFI K. S. , MAMUN A. A.
Published: May 2010

The basic features of obliquely propagating dust ion-acoustic (DIA) solitary waves in an adiabatic magnetized dusty electronegative plasma (containing Boltzmann electrons, Boltzmann negative ions, adiabatic positive ions, and negatively charged stationary dust) have been investigated. The reductive perturbation method has been employed to derive the Korteweg–de Vries (KdV) equation which admits a solitary wave solution. The combined effects of ion adiabaticity and external magnetic field (obliqueness), which are found to significantly modify the basic features of the small but finite-amplitude DIA solitary waves, are explicitly examined. The implications of our results in space and laboratory dusty plasmas are briefly discussed.
Adolescent development of psychosis as an outcome of hearing impairment: a 10-year longitudinal study
Authors: van der Werf M. , Thewissen V. , Dominguez M. D. , Lieb R. , Wittchen H. , van Os J.
Published: May 2010

Background

It has long been acknowledged that hearing impairment may increase the risk for psychotic experiences. Recent work suggests that young people in particular may be at risk, indicating a possible developmental mechanism.

Method

The hypothesis that individuals exposed to hearing impairment in early adolescence would display the highest risk for psychotic symptoms was examined in a prospective cohort study of a population sample of originally 3021 adolescents and young adults aged 14–24 years at baseline, in Munich, Germany (Early Developmental Stages of Psychopathology Study). The expression of psychosis was assessed at multiple time points over a period of up to 10 years, using a diagnostic interview (Munich Composite International Diagnostic Interview; CIDI) administered by clinical psychologists.

Results

Hearing impairment was associated with CIDI psychotic symptoms [odds ratio (OR) 2.04, 95% confidence interval (CI) 1.10–3.81], particularly more severe psychotic symptoms (OR 5.66, 95% CI 1.64–19.49). The association between hearing impairment and CIDI psychotic symptoms was much stronger in the youngest group aged 14–17 years at baseline (OR 3.28, 95% CI 1.54–7.01) than in the older group aged 18–24 years at baseline (OR 0.82, 95% CI 0.24–2.84).

Conclusions

The finding of an age-specific association between hearing impairment and psychotic experiences suggests that disruption of development at a critical adolescent phase, in interaction with other personal and social vulnerabilities, may increase the risk for psychotic symptoms.
Psychotic-like experiences in the general population: characterizing a high-risk group for psychosis
Authors: Kelleher I. , Cannon M.
Published: May 2010

Recent research shows that psychotic symptoms, or psychotic-like experiences (PLEs), are reported not only by psychosis patients but also by healthy members of the general population. Healthy individuals who report these symptoms are considered to represent a non-clinical psychosis phenotype, and have been demonstrated to be at increased risk of schizophrenia-spectrum disorder. Converging research now shows that this non-clinical psychosis phenotype is familial, heritable and covaries with familial schizophrenia-spectrum disorder. A review of the research also shows that the non-clinical phenotype is associated extensively with schizophrenia-related risk factors, including social, environmental, substance use, obstetric, developmental, anatomical, motor, cognitive, linguistic, intellectual and psychopathological risk factors. The criterion and construct validity of the non-clinical psychosis phenotype with schizophrenia demonstrates that it is a valid population in which to study the aetiology of psychosis. Furthermore, it suggests shared genetic variation between the clinical and non-clinical phenotypes. Much remains to be learned about psychosis by broadening the scope of research to include the non-clinical psychosis phenotype.
Evolution of neuropsychological dysfunction during the course of schizophrenia and bipolar disorder
Authors: Lewandowski K. E. , Cohen B. M. , Öngur D.
Published: May 2010

Background

Neurocognitive dysfunction in schizophrenia (SZ), bipolar (BD) and related disorders represents a core feature of these illnesses, possibly a marker of underlying pathophysiology. Substantial overlap in domains of neuropsychological deficits has been reported among these disorders after illness onset. However, it is unclear whether deficits follow the same longitudinal pre- and post-morbid course across diagnoses. We examine evidence for neurocognitive dysfunction as a core feature of all idiopathic psychotic illnesses, and trace its evolution from pre-morbid and prodromal states through the emergence of overt psychosis and into chronic illness in patients with SZ, BD and related disorders.

Method

Articles reporting on neuropsychological functioning in patients with SZ, BD and related disorders before and after illness onset were reviewed. Given the vast literature on these topics and the present focus on cross-diagnostic comparisons, priority was given to primary data papers that assessed cross-diagnostic samples and recent meta-analyses.

Results

Patients with SZ exhibit dysfunction preceding the onset of illness, which becomes more pronounced in the prodrome and early years following diagnosis, then settles into a stable pattern. Patients with BD generally exhibit typical cognitive development pre-morbidly, but demonstrate deficits by first episode that are amplified with worsening symptoms and exacerbations.

Conclusions

Neuropsychological deficits represent a core feature of SZ and BD; however, their onset and progression differ between diagnostic groups. A lifetime perspective on the evolution of neurocognitive deficits in SZ and BD reveals distinct patterns, and may provide a useful guide to the examination of the pathophysiological processes underpinning these functions across disorders.
Pathways between early visual processing and functional outcome in schizophrenia
Authors: Rassovsky Y. , Horan W. P. , Lee J. , Sergi M. J. , Green M. F.
Published: May 2010

Background

Early visual processing deficits are reliably detected in schizophrenia and show relationships to poor real-world functioning. However, the nature of this relationship is complex. Theoretical models and recent studies using statistical modeling approaches suggest that multiple intervening factors are involved. We previously reported that a direct and significant association between visual processing and functional status was mediated by a measure of social perception. The present study examined the contribution of negative symptoms to this model.

Method

We employed structural equation modeling (sem) to test several models of outcome, using data from 174 schizophrenia out-patients. Specifically, we examined the direct and indirect relative contributions of early visual processing, social perception and negative symptoms to functional outcome.

Results

First, we found that, similar to social perception, a measure of negative symptoms mediated the association between visual information processing and functional status. Second, we found that the inclusion of negative symptoms substantially enhanced the explanatory power of the model. Notably, it was the experiential aspect of negative symptoms (avolition and anhedonia) more than the expressive aspect (affective flattening and alogia) that accounted for significant variance in functional outcome, especially in the social component of the construct of functional outcome.

Conclusions

Social perception and negative symptoms play relevant roles in functional impairment in schizophrenia. Both social perception and negative symptoms statistically mediate the connection between visual processing and functional outcome. However, given the lack of association between social perception and negative symptoms, these constructs appear to have an impact on functioning through separate pathways.
Psychophysiological responses to different levels of cognitive and physical workload in haptic interaction
Authors: Novak Domen , Mihelj Matjaž , Munih Marko
Published: May 2010

Psychophysiological measurements, which serve as objective indicators of psychological state, have recently been introduced into human–robot interaction. However, their usefulness in haptic interaction is uncertain, since they are influenced by physical workload. This study analyses psychophysiological responses to a haptic task with three different difficulty levels and two different levels of physical load. Four physiological responses were recorded: heart rate, skin conductance, respiratory rate and skin temperature. Results show that mean respiratory rate, respiratory rate variability and skin temperature show significant differences between difficulty levels regardless of physical load and can be used to estimate cognitive workload in haptic interaction.
Democratic decentralization in sub-Saharan Africa: its contribution to forest management, livelihoods, and enfranchisement
Authors: RIBOT J. C. , LUND J. F. , TREUE T.
Published: May 2010

Efforts to promote popular participation in forest management in Sub-Saharan Africa have faced many obstacles and disappointments. Although promises of improvements in relation to forest management, rural livelihoods and local enfranchisement have been achieved in some cases, accounts of frustration outnumber those of success. Focusing on participation through democratic decentralization (namely the transfer of meaningful discretionary powers to local representative authorities), this paper reviews recent empirical studies on the outcomes of popular participation in forest management. The implementation of decentralization of forest management, and ecological, livelihood and democracy outcomes are examined, and misconceptions in analyses of decentralized forestry are explored. The expected benefits of democratic decentralization within forestry are rarely realized because democratic decentralization is rarely established. In most cases, local authorities do not represent the local population or their space of discretion is so narrow that they have little effect on management. There is little official local management taking place, even under so-called decentralized or participatory management arrangements. If ever significant space for local discretion under democratic authorities is created, researchers will have the opportunity to study whether democratic decentralization can deliver the theoretically promised positive outcomes. Nevertheless, some cases shed light on effects of local decision making. Three general observations are made on effects of decentralization. First, environmental, livelihood and democracy objectives are not always mutually reinforcing, and under some circumstances they may be at odds. Second, environmental effects of improved forest management often result in benefits accruing to distant or higher-scale aggregate populations, while local communities carry the costs. Third, poor peoples' use of natural resources to maintain their livelihoods often conflicts with profit and revenue interests of local elites, national commercial interests and governments. A negotiated minimum social and environmental standards approach to decentralization of forest management may safeguard essential ecological functions and at the same time protect essential livelihood and economic values of forests at all scales of society. The remainder of decisions, such as how forests are used, by whom and for what, could then be safely placed at the discretion of responsive local representatives.
Avian biology, the human influence on global avian influenza transmission, and performing surveillance in wild birds
Authors: Gibbs Samantha E. J.
Published: May 2010

This paper takes a closer look at three interrelated areas of study: avian host biology, the role of human activities in virus transmission, and the surveillance activities centered on avian influenza in wild birds. There are few ecosystems in which birds are not found. Correspondingly, avian influenza viruses are equally global in distribution, relying on competent avian hosts. The immune systems, annual cycles, feeding behaviors, and migration patterns of these hosts influence the ecology of the disease. Decreased biodiversity has also been linked to heightened disease transmission in several disease systems, and it is evident that active destruction and modification of wetland environments for human use is impacting avian populations drastically. Legal and illegal trade in wild birds present a significant risk for introduction and maintenance of exotic diseases. After the emergence of HPAI H5N1 in Hong Kong in 1996 and the ensuing geographic spread of outbreaks after 2003, both infected countries and those at risk of introduction began intensifying avian influenza surveillance efforts. Several techniques for sampling wild birds for influenza viruses have been applied. Benefits, problems, and biases exist for each method. The wild bird avian influenza surveillance programs taking place across the continents are now scaling back due to the rise of other spending priorities; hopefully the lessons learned from this work will be preserved and will inform future research and disease outbreak response priorities.
Study of putative microfossils in space dust from the stratosphere
Authors: Rauf Kani , Hann Anthony , Wallis Max , Wickramasinghe Chandra
Published: May 2010

Interplanetary dust particles (IDPs) were recovered from the stratosphere by a cryosampler flown below a balloon flying at altitudes of 20–41 km. The present study uses high-resolution scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) spectrophotometry to examine fresh samples collected at 38–41 km. The SEM observations confirm the presence of 7–32 μm sized clusters of coccoidal (0.4–1.3 μm in diameter) and rod-shaped (0.6–2.5 μm in length) objects as components of the IDP complex. Many single globules (1.6–9.0 μm in diameter) are also observed, some of which exhibit a rough surface with filamentous features of variable lengths. The spectrophotometry of the particles in aggregate reveals a prominent peak centred at 216 nm, which is remarkably similar to that of diatoms and close to the UV astronomical feature of 217.5 nm that has been identified as the spectral characteristic of aromatic hydrocarbons. The evidence presented here suggests that the stratospheric particles are IDPs comprising an assortment of materials among which are included microfossil-like features in variable sizes and forms, such as coccoids, rods and filaments.
Virtual SEM (VSEM)—Ongoing Development of Teaching Resources
Authors: Caldwell N.H.M. , Martin G.C. , Mitchell A.L. , Holburn D.M. , Breton B.C.
Published: May 2010

In the last decade, microscopy has been successfully employed by a number of research groups as a means of instilling enthusiasm for science and technology into students of all ages, especially school children . Remote microscopy (or telemicroscopy) and virtual microscopy (in the form of software simulators) continue to play important roles in these efforts and also in the teaching and training of new microscopists . Such work and associated electronic teaching resources have become prominent features of conferences such as Microscopy & Microanalysis.
Pioneers in Optics: Giovanni Battista Amici and Girolamo Cardano
Authors: Davidson Michael W.
Published: May 2010

Giovanni Amici was an Italian microscopist, astronomer, optical instrument designer, and botanist who is best known as the achromatic lens inventor. He also designed reflecting telescopes and introduced a lens for the inspection of an objective's rear focal plane, termed the Amici-Bertrand lens. Aditionally, in 1850 he invented the water immersion lens.
Formation of New Proteins Seen from the Beginning
Authors: Carmichael Stephen W.
Published: May 2010

All cells have the ability to synthesize and secrete proteins. Although many details of this process are well-known, Martin Kampmann and Günter Blobel recently highlighted two “landmark papers” that used cryo-electron microscopy (cryoEM) to obtain information at subnanometer resolution, which provided direct visualization of nascent polypeptide chains in the tunnel with ribosomes . It is known that the signal peptide (the first few amino acids on the amino terminal that do not become part of the final polypeptide) emerges from a ribosome and engages the signal recognition particle (SRP) in the cytoplasm, and this complex is directed to the SRP receptor on the endoplasmic reticulum (ER). The SRP is released, the signal peptide enters the protein-conducting channel (PCC), and the nascent polypeptide chain (that will become the protein) enters the lumen of the ER.
The Preparation of Porous Materials Using Liquid Metal Impregnation for BSE Characterization with a Scanning Electron Microscope
Authors: Steele James H.
Published: May 2010

The infiltration of porous and particulate materials for metallographic examination with low-melting alloys was first described by Rose and DeRoos . The use of Wood's metal to fill porosity in sandstone was reported by Craze , by Dullien , and by Yadev et al. . Changes in pore structure and phase dispersions in iron ore pellets after simulated blast furnace reduction were reported by Shultz et al. , wherein liquid Bi-Sn impregnation was used to prepare cross sections of deformed and reduced pellets for backscatter electron imaging. Steele and Engel also applied the technique to examine the microstructure in commercial boron nitride (BN). In that study porosity formed by leaching the B2O3phase was filled with liquid metal to allow argon-ion etching to expose the BN microstructure. The characterization of cracks and porosity in cement-based materials after filling with Wood's metal has been reported by Nemati et al. . Cracks developed during compression testing of marble were studied byin-situmetal impregnation in Chang et al. .
The (classical) Realist vision of global reform
Authors: Scheuerman William E.
Published: May 2010

Most Realists today oppose far-reaching global reform on the grounds that it represents unrealistic and potentially irresponsible ‘utopianism’. An earlier generation of mid-century Realists, however, not only supported serious efforts at radical international reform but also developed a theoretically impressive model for how to bring it about. They considered the possibility of post-national political orders and ultimately a world state as desirable long-term goals, but only if reformers could simultaneously generate the thick societal background (or what they called ‘supranational society’) required by any viable order ‘beyond the nation state’. As they fail to engage constructively with proposals for global reform, present-day Realists betray their own intellectual tradition. By reconsidering the subterranean legacy of Realist reformism as advanced by mid-century international thinkers (e.g. E.H. Carr, John Herz, Hans Morgenthau, Reinhold Niebuhr, and Frederick Schuman), the essay provides a revisionist reading of the history of twentieth-century international theory, while also highlighting its significance for ongoing debates about global reform.
Towards evidence-based clinical supervision: the development and evaluation of four CBT guidelines
Authors: Milne Derek , Dunkerley Chris
Published: May 2010

Clinical supervision is central to evidence-based practice (EBP) and continuing professional development (CPD), but the evidence base has made little impact on supervision, a major form of CPD. We unite the two by developing four evidence-based guidelines for cognitive behavioural therapy (CBT) supervision. The guidelines were designed to address the supervision cycle (i.e. collaborative goal-setting; methods of facilitating learning; evaluation and feedback) within the context of the supervision alliance. Guideline development followed the National Institute for Clinical Excellence approach, including a representative stakeholder working group (with local service users and supervisees), a national group of supervisors and supervisor trainers, plus an expert reference group. A total of 106 such participants completed anad-hocguideline evaluation tool, designed to provide a multi-dimensional reaction evaluation of the guidelines. The guidelines were all rated favourably, satisfying the key initial criteria of accuracy and acceptability, and were judged to represent a CBT approach to supervision. It is concluded that the use of the guidelines might help CBT supervisors to better meet demands for CPD (including specialization in supervision) and EBP.
Temporal and spatial variability and controls of soil respiration in a temperate steppe in northern China
Authors: Chen Quansheng , Wang Qibing , Han Xingguo , Wan Shiqiang , Li Linghao
Published: May 2010

In this study, soil respiration and environmental variables were examined to explore the temporal and spatial variability and controls of soil respiration in eight plant communities along an east–west transect in a temperate steppe of Inner Mongolia, China. Our results show that there was substantial temporal (coefficient of variation (CV) = 58.6 ± 1.54%,n= 14) and spatial variability (CV = 32.6 ± 2.65%,n= 8) in soil respiration. Soil temperature and moisture were more important than plant growth in controlling the seasonal patterns of within‐site soil respiration in all the eight steppe communities. Spatial differences in soil respiration rate could be mainly attributed to the differences in soil moisture and net primary productivity (NPP) among the study sites, whereas soil temperature played a minor role in regulating the spatial pattern of soil respiration. Significantly, positive site‐to‐site correlations were found between soil respiration and site soil traits such as soil C, N, and clay contents. In contrast, soil respiration was negatively correlated with soil bulk density and sand content. These findings indicate that the relative importance of abiotic and biotic factors in regulating soil respiration differs temporally from spatially. The conclusions drawn from the present study provide valuable information for developing future models of soil respiration driven by site climatic and soil variables, applicable for large‐scale estimates of soil respiration in grassland ecosystems.
Plasma sheet thickness during a bursty bulk flow reversal
Authors: Panov E. V. , Nakamura R. , Baumjohann W. , Sergeev V. A. , Petrukovich A. A. , Angelopoulos V. , Volwerk M. , Retinò A. , Takada T. , Glassmeier K.‐H. , McFadden J. P. , Larson D.
Published: May 2010

On 17 March 2008 around 0912 UT the five THEMIS spacecraft P1–P5 were in the plasma sheet between 2200 and 2300 h magnetic local time (MLT), covering radial distances between 15 Earth radii (Re) (P1) and 9 Re (P5). All the spacecraft consecutively observed a bursty bulk flow (BBF) that traveled earthward, slowed down from 400 km/s to 50 km/s between P1 and P5, and then turned in the opposite direction. The most tailward‐located spacecraft, P1 and P2, detected thinning and then thickening of the plasma sheet around the time of the flow direction change. Meanwhile, the other three THEMIS spacecraft, which were located in a more dipolar region, observed plasma sheet thickening and then thinning. Observations indicated that the thinning/thickening was stronger around the BBF funnel. Further, during the interaction of the earthward‐flowing BBF plasma with the Earth's dipolar field lines, the BBF was deflected by about 70° at a scale of about 5 Re. The radial pressure gradient was substantially increased when the BBF reached the shortest radial distance to the Earth and substantially decreased after the tailward plasma flow. We conclude that the tailward pressure pulse produced by the enhanced radial pressure gradients after the earthward BBF stopped could be responsible for the observed tailward plasma flows.
Radiation partitioning and its relation to environmental factors above a meadow ecosystem on the Qinghai‐Tibetan Plateau
Authors: Zhang Xiaochun , Gu Song , Zhao Xinquan , Cui Xiaoyong , Zhao Liang , Xu Shixiao , Du Mingyuan , Jiang Sha , Gao Yubao , Ma Chun , Tang Yanhong
Published: May 2010

Understanding the energy balance on the Qinghai‐Tibetan Plateau is essential for better prediction of global climate change. To characterize the energy balance on the plateau, we examined the radiation partitioning over a Kobresia meadow, the most widely distributed vegetation on the plateau, for the period from 2002 to 2005. The incident solar radiation (Rs) and net radiation (Rn) averaged 6298 and 2779 MJ m−2 yr−1, respectively. The albedo averaged 0.220 annually, with a slightly low value of 0.202 in the growing season from May to September. An increase in soil water or leaf area index was correlated with a decrease of albedo over the meadow. The annual solar radiation lost 34% as longwave radiation, which was higher than values reported for lowland grasslands. The annual radiation efficiency (Rn/Rs) over the meadow, at an average of 0.44, was, however, much lower than that for lowland grasslands. The net longwave radiation (Ln) and the normalized effective radiation (Ln/Rs) over the meadow were much higher than that for the global surface or for lowland grasslands, indicating that the longwave exchange between alpine meadow and atmosphere is the most important component of energy losses. A path analysis suggests that the water vapor pressure, air temperature, and cloud cover are the major factors governing the variations of both the net radiation and the net longwave radiation in the alpine meadow ecosystem.
Understanding predictive uncertainty in hydrologic modeling: The challenge of identifying input and structural errors
Authors: Renard Benjamin , Kavetski Dmitri , Kuczera George , Thyer Mark , Franks Stewart W.
Published: May 2010

Meaningful quantification of data and structural uncertainties in conceptual rainfall‐runoff modeling is a major scientific and engineering challenge. This paper focuses on the total predictive uncertainty and its decomposition into input and structural components under different inference scenarios. Several Bayesian inference schemes are investigated, differing in the treatment of rainfall and structural uncertainties, and in the precision of the priors describing rainfall uncertainty. Compared with traditional lumped additive error approaches, the quantification of the total predictive uncertainty in the runoff is improved when rainfall and/or structural errors are characterized explicitly. However, the decomposition of the total uncertainty into individual sources is more challenging. In particular, poor identifiability may arise when the inference scheme represents rainfall and structural errors using separate probabilistic models. The inference becomes ill‐posed unless sufficiently precise prior knowledge of data uncertainty is supplied; this ill‐posedness can often be detected from the behavior of the Monte Carlo sampling algorithm. Moreover, the priors on the data quality must also be sufficiently accurate if the inference is to be reliable and support meaningful uncertainty decomposition. Our findings highlight the inherent limitations of inferring inaccurate hydrologic models using rainfall‐runoff data with large unknown errors. Bayesian total error analysis can overcome these problems using independent prior information. The need for deriving independent descriptions of the uncertainties in the input and output data is clearly demonstrated.
Uranium on the Moon: Global distribution and U/Th ratio
Authors: Yamashita N. , Hasebe N. , Reedy R. C. , Kobayashi S. , Karouji Y. , Hareyama M. , Shibamura E. , Kobayashi M.‐N. , Okudaira O. , d'Uston C. , Gasnault O. , Forni O. , Kim K. J.
Published: May 2010

The Kaguya Gamma‐Ray Spectrometer uniquely identified uranium gamma‐ray lines from the Moon with a superior energy resolution of ∼1%. A global lunar map of uranium distribution is derived for the first time. It was found that uranium abundances vary up to 2 ppm with an average of ∼0.3 ppm, while the average thorium abundance was ∼1.2 ppm. From these analyses, significant variation in U/Th ratio was found in the farside of the Moon that had not been reported by previous observations or in lunar materials. Our observations suggest that the lunar highland is not as uniform as has been long considered.
Magnetic Resonance Imaging of Regional Hemodynamic and Cerebrovascular Recovery after Lateral Fluid-Percussion Brain Injury in Rats
Authors: Hayward Nick Mark Edward Alexander , Tuunanen Pasi I , Immonen Riikka , Ndode-Ekane Xavier Ekolle , Pitkänen Asla , Gröhn Olli
Published: May 2010

Hemodynamic and cerebrovascular factors are crucially involved in secondary damage after traumatic brain injury (TBI). With magnetic resonance imaging, this study aimed to quantify regional cerebral blood flow (CBF) by arterial spin labeling and cerebral blood volume by using an intravascular contrast agent, during 14 days after lateral fluid-percussion injury (LFPI) in rats. Immunohistochemical analysis of vessel density was used to evaluate the contribution of vascular damage. Results show widespread ipsilateral and contralateral hypoperfusion, including both the cortex and the hippocampus bilaterally, as well as the ipsilateral thalamus. Hemodynamic unrest may partly be explained by an increase in blood vessel density over a period of 2 weeks in the ipsilateral hippocampus and perilesional cortex. Furthermore, three phases of perilesional alterations in CBF, progressing from hypoperfusion to normal and back to hypoperfusion within 2 weeks were shown for the first time in a rat TBI model. These three phases were similar to hemodynamic fluctuations reported in TBI patients. This makes it feasible to use LFPI in rats to study mechanisms behind hemodynamic changes and to explore novel therapeutic approaches for secondary brain damage after TBI.
Open Source Kinesin-1 Stochastic Simulation and Gliding Assay Tracking Software
Authors: Herskowitz Lawrence , Salvagno Anthony , Josey Brian , Maloney Andy , Koch Steven
Published: May 2010

Kinesin-1 (conventional kinesin) is a homodimeric motor protein important for axonal transport. It has been well studied through ensemble and single-molecule assays. However, the enzymatic stepping cycle is complex, with many rate constants that are modulated by interaction of the two motor domains. This makes it difficult to predict how changes in a given rate constant may affect observable properties such as processivity, velocity, or stall force. We have written a simulation of kinesin walking using a Stochastic Simulation Algorithm. The model allows for interactions between the heads, and includes states that are not considered part of the normal cycle. This adds to the complexity of the model but also allows for probing rare events, such as those that lead to a finite processivity. Also included are rate constant dependencies on force and concentrations of ATP, ADP, and Pi, which may provide insight into other processes under investigation, such as kinesin backstepping. We intend to use the simulation to aid in interpreting our own gliding motility assay results and to place upper and lower limits on values for rate constants. Our source and executable codes will be freely available.

Acknowledgements:

This work was supported by the DTRA CB Basic Research Program under Grant No. HDTRA1-09-1-008.
Design and development of a Europe-wide case specific monitoring method
Authors: Ziegler Angelika , Mönkemeyer Wenke , Wilhelm Ralf , Schmidt Kerstin
Published: May 2010

Directive 2001/18 EC demands the cultivation of genetically modified organisms (GMO) to be accompanied by post-market environmental monitoring (PMEM). It is composed of a general surveillance for unanticipated adverse effects and case specific monitoring (CSM), which is set up to reduce substantial uncertainties in relevant risk scenarios identified in the environmental risk assessment. PMEM should also allow early identification of potential long-term effects of cultivating GMOs. It should facilitate decisions in risk management.In this project, a method for a Europe-wide CSM was to be developed. Starting with critical questions from ERA, exposure scenarios (first for non target organisms, later for all other partitions of the ERA) were to be designed and potential monitoring characters ought to be identified. This was meant to facilitate the identification of potential CSM approach. Consideration was focussed on potatoes and wheat. Relevant pathways of plant-organism interactions through nutrients, toxins or mechanisms of attraction and defence were reviewed. The employment of CSM was reconsidered, taking into account variability among existing potato and wheat varieties, respectively, and environmental conditions.Multiple factors drive variations and fluctuations in metabolites as well as in populations of potentially affected organisms. Moreover, management goals for breeding are missing. These counteract the concept and usability of CSM approaches related to such scenarios for causes and effects as well as reasonable thresholds for decision making cannot be deduced.
Versatility in the acquisition of energy and carbon sources by the Apicomplexa
Authors: Polonais Valerie , Soldati‐Favre Dominique
Published: May 2010

Members of the phylum Apicomplexa are motile and rapidly dividing intracellular parasites, able to occupy a large spectrum of niches by infecting diverse hosts and invading various cell types. As obligate intracellular parasites, most apicomplexans only survive for a short period extracellularly, and, during this time, have a high energy demand to power gliding motility and invasion into new host cells. Similarly, these fast‐replicating intracellular parasites are critically dependent on host‐cell nutrients as energy and carbon sources, noticeably for the extensive membrane biogenesis imposed during growth and division. To access host‐cell metabolites, the apicomplexans Toxoplasma gondii and Plasmodium falciparum have evolved strategies that exquisitely reflect adaptation to their respective niches. In the present review, we summarize and compare some recent findings regarding the energetic metabolism and carbon sources used by these two genetically tractable apicomplexans during host‐cell invasion and intracellular growth and replication.
Direct Wolf summation of a polarizable force field for silica
Authors: Brommer Peter , Beck Philipp , Chatzopoulos Andreas , Gähler Franz , Roth Johannes , Trebin Hans-Rainer
Published: May 2010

We extend the Wolf direct, pairwise r−1 summation method with spherical truncation to dipolar interactions in silica. The Tangney–Scandolo interatomic force field for silica takes regard of polarizable oxygen atoms whose dipole moments are determined by iteration to a self-consistent solution. With Wolf summation, the computational effort scales linearly in the system size and can easily be distributed among many processors, thus making large-scale simulations of dipoles possible. The details of the implementation are explained. The approach is validated by estimations of the error term and simulations of microstructural and thermodynamic properties of silica.
Insights into mechanistic photochemistry of urea
Authors: Cui Ganglong , Ding Lina , Feng Feng , Liu Yajun , Fang Weihai
Published: May 2010

In this work, we have studied the mechanistic photochemistry of urea (NH2CONH2) by means of ab initio calculations on the stationary and intersection structures in the lowest three electronic states (S1, T1, and S0). Two dominant decay channels were found for NH2CONH2 to decay from the S1 state, internal conversion to the S0 state via the S1/S0 minimum-energy conical intersection, and intersystem crossing to the T1 state in the vicinity of the S1/T1 minimum-energy crossing point. Once in the S0 state, the isomerization and deamination reactions prevail due to their low barrier heights. This is different from the mechanism proposed experimentally, in which the deamination and dehydration reactions proceed in the S1 and T1 states. The CN bond cleavage was determined to occur mainly along the T1 pathway as a result of the S1/T1 intersystem crossing.
Self-similar motion of three point vortices
Authors: Aref Hassan
Published: May 2010

One of the counter-intuitive results in the three-vortex problem is that the vortices can converge on and meet at a point in a finite time for certain sets of vortex circulations and for certain initial conditions. This result was already included in Gröbli’s thesis of 1877 and has since been elaborated by several authors. It arises from an investigation of motions where the vortex triangle retains its shape for all time, but not its size. We revisit these self-similar motions, develop a new derivation of the initial conditions that lead to them, and derive a number of formulae pertaining to the rate of expansion or collapse and the angular frequency of rotation, some of which appear to be new. We also pursue the problem of linear stability of these motions in detail and, again, provide a number of formulae, some of which are new. In particular, we determine all eigenmodes analytically.
Greatly enhanced adsorption and catalytic activity of Au and Pt clusters on defective graphene
Authors: Zhou Miao , Zhang Aihua , Dai Zhenxiang , Zhang Chun , Feng Yuan Ping
Published: May 2010

We report an investigation on CO oxidation catalyzed by Au8 or Pt4 clusters on defective graphene using first-principles approach based on density functional theory. The simplest single-carbon-vacancy defect on graphene was found to play an essential role in the catalyzed chemical reaction of CO oxidation. When supported on a defect-free graphene sheet, the reaction barrier of CO oxidation catalyzed by Au8 (Pt4) clusters was estimated to be around 3.0 eV (0.5 eV), and when adsorbed on defective graphene, the reaction barrier was greatly reduced to around 0.2 eV (0.13 eV).
Load-driven morphological evolution in covalently bridged multiwalled carbon nanotubes
Authors: Huang Xu , Zhang Sulin
Published: May 2010

Under pure bending or compression multiwalled carbon nanotubes (MWCNTs) with interwall covalent bridges exhibit evolving morphologies, ranging from uniform deformation, wavelike rippling, to Yoshimura (diamond-shaped) pattern. Using large-scale coarse-grained simulations, we map out the morphological phase diagram in the space of applied strain and interwall bridging density and find that the three deformation phases are separated by two linear transition boundaries. Our energetics analyses reveal that the relative significance of the in-plane deformation energy and the interwall bridging energy determines the shape space of MWCNTs. The multiple morphological transformations open pathways for mechanically tuning the electronic and magnetic properties of MWCNTs.
Convergence of the multipole expansion for 1,2 Coulomb interactions: The modified multipole shifting algorithm
Authors: Solano C. J. F. , Pendás A. Martín , Francisco E. , Blanco M. A. , Popelier P. L. A.
Published: May 2010

A force field that accounts for the quantum chemical reality of interacting atoms must include Coulomb interactions between bonded atoms. The short-range nature of such 1,2 interactions necessitates atomic multipole moments in addition to point charges. However, the close proximity of bonded atoms would normally lead to a divergent multipolar expansion. A special algorithm presented here, within the scope of the previously presented multipole shifting method [M. Rafat and P. L. A. Popelier, J. Chem. Phys. 124, 144102 (2006)], shows that convergence can nevertheless be achieved by a suitable selection of multipole displacements. The algorithm is applied to improve the convergence of the multipolar expansion within the quantum theory of atoms in molecules approach.
Locating a small change in a multiple scattering environment
Authors: Larose Eric , Planes Thomas , Rossetto Vincent , Margerin Ludovic
Published: May 2010

This article presents an imaging technique to locate a weak perturbation in a multiple scattering environment. We derive a formula to predict the spatiotemporal decorrelation of diffuse coda waves induced by an extra scatterer. Locating this new defect is formulated as an inverse problem which is solved by a maximum likelihood approach. Using elastic waves in the 50–400 kHz frequency band, we recover the position of a millimetric hole drilled in a concrete sample with a precision of a few centimeter. Note that the size of the defect is comparable to the size of the myriads of heterogeneities constituting the sample.
Band gap tuning in GaN through equibiaxial in-plane strains
Authors: Dong L. , Yadav S. K. , Ramprasad R. , Alpay S. P.
Published: May 2010

Structural transformations and the relative variation in the band gap energy (ΔEg) of (0001) gallium nitride (GaN) films as a function of equibiaxial in-plane strains are studied by density functional theory. For relatively small compressive misfits (−6%–0%), the band gap is estimated to be around its strain-free value, while for small tensile strains (0%–6%), it decreases by approximately 45%. In addition, at large tensile strains (>14.5%), our calculations indicate that GaN may undergo a structural phase transition from wurtzite to a graphitelike semimetallic phase.
Patient and general practitioner attitudes to healthy lifestyle behaviours and medication following coronary heart disease: an exploratory study
Authors: Speechly Catherine , Bridges-Webb Charles , McKenzie Suzanne , Zurynski Yvonne , Lucas Alison
Published: May 2010

Patients with coronary heart disease often engage in unhealthy lifestyle behaviours. We explored patients’ and general practitioners’ (GPs’) perceptions about the effectiveness of healthy behaviours and medications for the prevention of further cardiovascular disease. This exploratory study used semi-structured interviews with eight Sydney GPs and 13 of their patients with coronary heart disease. Patients perceived medications to be more effective than healthy behaviours in improving specific aspects of cardiovascular health, such as angina symptoms, cholesterol and blood pressure, whilst GPs perceived that medications were more effective in patients they considered at highest cardiovascular risk, patients with uncontrolled risk factors, or where adherence to healthy behaviours was poor. Among patients we found a negative perception of the effort required to adhere to healthy behaviours and possible underestimation of their future cardiovascular risk. Patients valued support from peers and family. This study opens up avenues for investigation in further research, including whether patient adherence to healthy behaviours may be enhanced by the exploration of their perceptions about behaviour effectiveness, barriers and cardiovascular risk and by GP facilitation of practical supports.
General practitioners' decision to refer patients to dietitians: insight into the clinical reasoning process
Authors: Pomeroy Sylvia E. M. , Cant Robyn P.
Published: May 2010

The aim of this project was to describe general practitioners’ (GPs’) decision-making process for reducing nutrition risk in cardiac patients through referring a patient to a dietitian. The setting was primary care practices in Victoria. The method we employed was mixed methods research: in Study 1, 30 GPs were interviewed. Recorded interviews were transcribed and narratives analysed thematically. Study 2 involved a survey of statewide random sample of GPs. Frequencies and analyses of variance were used to explore the impact of demographic variables on decisions to refer. We found that the referral decision involved four elements: (i) synthesising management information; (ii) forecasting outcomes; (iii) planning management; and (iv) actioning referrals. GPs applied cognitive and collaborative strategies to develop a treatment plan. In Study 2, doctors (248 GPs, 30%) concurred with identified barriers/enabling factors for patients’ referral. There was no association between GPs’ sex, age or hours worked per week and referral factors. We conclude that a GP’s judgment to offer a dietetic referral to an adult patient is a four element reasoning process. Attention to how these elements interact may assist clinical decision making. Apart from the sole use of prescribed medications/surgical procedures for cardiac care, patients offered a dietetic referral were those who were considered able to commit to dietary change and who were willing to attend a dietetic consultation. Improvements in provision of patients’ nutrition intervention information to GPs are needed. Further investigation is justified to determine how to resolve this practice gap.
Ambiguous and arbitrary: the role of telephone interactions in rural health service delivery
Authors: Knight Kaye , Endacott Ruth , Kenny Amanda
Published: May 2010

Anecdotal evidence and a limited body of research suggests that telephone interactions between health care consumers and health professionals form an important part of unscheduled health care provision. However, very little is known about these interactions, particularly in the rural context. In rural Australia, there is a need to explore a range of models of service delivery. Telephone-based unscheduled care is one area that demands consideration. By defining unscheduled health care and delineating telephone-based unscheduled health care from other telehealth services, the concepts of formal and informal telephone-based unscheduled health care provision are explored. This article raises previously unasked questions about the role of telephone-based unscheduled health care in the rural context. As a dimension of health care that is poorly understood, the need for further conceptualisation, research and policy development in this area is highlighted.
The identity of Porphyra columbina (Bangiales, Rhodophyta) originally described from the New Zealand subantarctic islands
Authors: Nelson W. A. , Broom J. E. S.
Published: May 2010

Porphyra columbina Mont. (Bangiales, Rhodophyta) was collected in 1840 from the Auckland Islands in the New Zealand subantarctic region. This name has been applied to bladed Bangiales exhibiting a wide range of morphological forms, and found throughout the New Zealand region and in much of the southern hemisphere, particularly in Australia and Chile. By using morphological and anatomical characters as well as nSSU and rbcL sequence data, Montagne’s description of P. columbina is re-examined in the light of recent collections from the New Zealand region and the Southern Ocean. We conclude that P. columbina is primarily distributed in cold temperate conditions, including the Auckland, Campbell, Antipodes, Chatham and Falkland Islands, and is only rarely present on mainland New Zealand. Specimens from the type locality and other subantarctic locations have a rosette to ovate growth form and are typically less than 5 cm in height/width, with specimens from more northern locations including some ribbon-like growth forms. Thalli are purple to grey, bleaching golden green. Mature specimens have a distinctly spotted appearance, with conspicuous large, purple–red clusters of phyllospores and golden marginal areas of spermatangia. Five unique rbcL haplotypes, differing by 1–6 substitutions, were obtained from 26 specimens, with the most common haplotype found in specimens from the Auckland, Campbell and the Falkland Islands.