bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo relationship between thalamic nicotinic acetylcholine receptor occupancy rates and antiallodynic effects in a rat model of neuropathic pain: Persistent agonist binding inhibits the expression of antiallodynic effects
Authors: Ueda Masashi , Iida Yasuhiko , Yoneyama Tomoki , Kawai Tomoki , Ogawa Mikako , Magata Yasuhiro , Saji Hideo
Published: May 2010

We have recently clarified that nicotinic acetylcholine receptors (nAChRs) expressed in the thalamus play an important role in antiallodynic effects produced by the nAChR agonist, 5‐iodo‐3‐(2(S)‐azetidinylmethoxy)pyridine (5IA). This study aimed to reveal the in vivo relationship between thalamic nAChR occupancy rates and antiallodynic effects using 5IA and [125I]5IA. We partially ligated the sciatic nerve of a rat to induce neuropathic pain. Antiallodynic effects were evaluated at 15, 30, 60, and 90 min after intracerebroventricular (i.c.v.) administration of multiple doses (1–100 nmol) of 5IA by the von Frey filament test. Receptor occupancy rates were measured by autoradiography at 15 and 90 min after administration. Antiallodynic effects of repetitive treatment of 5IA (5 and 50 nmol) were also examined. A significant and dose‐dependent antiallodynic effect was observed 15 min after administration. It showed a good correlation with receptor occupancy rates (r= 0.97), indicating the binding of 5IA to nAChRs expressed in the thalamus involved in the antiallodynic effect. Five, 50, and 100 nmol of 5IA occupied the thalamic nAChRs until 90 min after administration, while the antiallodynic effect diminished. Five nanomoles of 5IA (which occupied 40% of thalamic nAChRs) showed a significant antiallodynic effect (percentage of the maximal possible effect (%MPE): 35 ± 7) after the second administration, while 50 nmol of 5IA (which occupied 80% of thalamic nAChRs) did not (%MPE: 7 ± 1). These findings suggest that not clearance of 5IA but desensitization of nAChRs caused by persistent binding of 5IA is responsible for the disappearance of antiallodynic effects. Synapse 65:77–83, 2011. © 2010 Wiley‐Liss, Inc.
Enhanced dopamine transporter function in striatum during nicotine withdrawal
Authors: Hadjiconstantinou Maria , Duchemin Anne‐Marie , Zhang Hailing , Neff Norton H.
Published: May 2010

Spontaneous and antagonist‐precipitated withdrawal from nicotine is characterized by marked deficits in extracellular dopamine (DA) in striatum, especially in nucleus accumbens, that have been thought to underlie the affective state associated with drug discontinuation. Uptake via the dopamine transporter (DAT) is a key mechanism for regulating the concentrations of extracellular DA. Accordingly, we questioned whether DAT expression and function are altered in striatum in nicotine withdrawal. Male mice, 30–35 g, were injected with nicotine free base 2 mg/kg, s.c., or saline four times daily for 14 days and euthanized 4–72 h after drug discontinuation. DA uptake into striatal synaptosomes was increased 12–24 h into nicotine withdrawal, and accompanied by elevated DAT mRNA in the substantia nigra pars compacta and ventral tegmental area, evaluated by in situ hybridization. The overflow of endogenous DA, measured under basal conditions in striatal slices ex vivo, was decreased during nicotine withdrawal in a time pattern paralleling to that of uptake. Added to striatal slices, the DAT inhibitor nomifensine reduced the observed difference in DA overflow between saline and nicotine withdrawn mice implying a role for the transporter. The presented data suggest that DAT is transiently upregulated in the striatum early during nicotine withdrawal, and enhanced transporter function contributes to the decreased extracellular DA levels. Synapse, 2011. © 2010 Wiley‐Liss, Inc.
Building Opportunity: Developing City Systems to Expand and Improve After School Programs
Authors: Holleman Martha A. , Jane Sundius M. , Bruns Eric J.
Published: May 2010

A growing body of research is examining the strengths and weaknesses of specific after school programs and their effect on youth outcomes. Few reviews, however, have sought to examine the components of citywide system‐building—to understand intentional efforts to develop, support and sustain high quality after school programming across a community. Beginning in the mid‐1990s and continuing through the present, private funders, public officials and program practitioners in cities across America have joined together to build systems to support the expansion and improvement of after school programs at the city‐level. This paper presents the community context and underlying principles that drove the development of Baltimore’s After‐School Strategy; articulates a set of system components derived from this experience and the available literature; and lays out future work to expand high quality after‐school opportunities for youth in Baltimore and in other distressed urban environments.
Therapeutic liver repopulation for phenylketonuria
Authors: Harding Cary O. , Gibson K. M.
Published: May 2010

Problems with long‐term dietary compliance in phenylketonuria (PKU) necessitate the development of alternative treatment approaches. Therapeutic liver repopulation with phenylalanine hydroxylase (PAH)‐expressing cells following hepatocyte or haematopoietic stem cell transplantation has been investigated as a possible novel treatment approach for PKU. Successful therapeutic liver repopulation requires both a stimulus for liver regeneration at the time of cell transplantation and a selective growth advantage for the PAH+ donor cells. Unfortunately, wild‐type PAH+ hepatocytes do not enjoy any growth advantage over PAH− cells. Successful correction of hyperphenylalaninemia following therapeutic liver repopulation has been accomplished only in an animal model that yields a selective advantage for the donor cells. Haematopoietic stem cell (HSC)‐mediated therapeutic liver repopulation has not been reported in any hyperphenylalaninemic system, and the success of HSC‐mediated liver repopulation for PKU may be limited by the slow kinetics of this approach. If therapeutic liver repopulation is to be employed successfully in humans with PKU, an effective method of providing a selective growth advantage for the donor cells must be developed. If this can be achieved, liver repopulation with 10–20% wild‐type hepatocytes will likely completely normalize Phe clearance in individuals with PKU.
Local coexistence and niche differences between the Lusitanian and Mediterranean pine voles (Microtus lusitanicus and M. duodecimcostatus)
Authors: Santos Sara M. , Mathias Maria da Luz , Mira António P.
Published: May 2010

In the present study, we analyzed the coexistence pattern of the Lusitanian pine vole (Microtus lusitanicus) and the Mediterranean pine vole (Microtus duodecimcostatus) in a potential area of sympatry in a Mediterranean landscape (Portugal). We also determined the relative contribution of local, landscape, and spatial factors explaining the differences in the distribution patterns of the two species in the region. Using a kriging interpolation method, we obtained a map of sympatric and allopatric areas of species occurrence. The estimated sympatry area corresponded to a northwest–southeast belt representing 11.3% of the study area. Habitat niche differences were assessed with binomial GLMs followed by a variance partitioning. At a local scale, higher altitude, higher cover of shrubs, lower clay content in the soil, and lower cover of tree canopy were the most important factors distinguishing M. lusitanicus presence sites from those with M. duodecimcostatus. At a larger scale, the presence of forest landscape units and the low abundance of “montado” units were the most influencing landscape factors in the identification of M. lusitanicus occurrence sites when compared to M. duodecimcostatus. Our results suggested that local coexistence of M. lusitanicus and M. duodecimcostatus in the field is a rare event. The differences in distribution patterns of the two pine vole species were mostly explained by fine‐scale environmental factors and by shared spatial effects.
The Interpretative Chain of Modern Chinese Literature and the Formation of the “New Tradition”
Authors: Rumin WEN
Published: May 2010

The modern Chinese literary tradition that emerged along with the May Fourth Movement has already spilt over into every aspect of contemporary Chinese life. As shaping force in Chinese literary and cultural evolution, this “New Tradition” calls for renewed critical scrutiny. In the face of new contemporary challenges that threaten to subvert the May Fourth literary tradition, the value of this tradition calls for grave reconsideration. This paper, as part of a research on the formation of the New Tradition, views this literary tradition as “a chain of interpretative variations” which has undergone the incessant interpretative selections, siftings, and moldings of historians as well as literary critics of various historical phases, and which nevertheless cannot go beyond the limits of their times. This paper examines how literary historians and critics from the 1920s to the 1940s evaluated the New Literature, how they constructed their perspectives on literary history on the basis of their evaluation, how their theories and ideas have come through the decades to bear upon people’s conceptualization and evaluation of the New Literature. The paper aims to map the trajectory of the cognizance of modern Chinese literature as well as some of the significant stages in the early days of the New Tradition.
Clinical Evaluation of Ultra-Low Dose Contrast-Enhanced CT in Patients Presenting with Acute Ureteric Colic
Authors: Fowler J.C. , Cutress M.L. , Abubacker Z. , Saleemi M.A. , Alam A. , Shekhdar J. , Wagstaff H.
Published: May 2010

Objective:

To determine the diagnostic accuracy of ultra-low dose contrast-enhanced CT (ULDCECT) and its ability to measure differential renal function (DRF) in patients presenting clinically with acute ureteric colic by comparison to IVU (using an equivalent radiation exposure) and DMSA, respectively.

Patients and methods:

Fifty-three patients presenting clinically with acute ureteric colic underwent IVU, ULDCECT and DMSA on the same day of their hospital admission. Diagnostic accuracy of ULDCECT and IVU was compared to interventional findings and clinical outcome. Estimation of DRF by ULDCECT was derived through measurement of enhancing renal volumes and DMSA.

Results:

ULDCECT had superior sensitivity (97%) and specificity (100%) in the identification of renal tract stone disease compared to IVU (84 and 95% respectively), with comparable radiation exposure (1.7 mSv versus 1.4 mSv). Furthermore, ULDCECT revealed non-urological pathology in eight patients (15%), including perforated abdominal viscus and acute appendicitis. There was a very good correlation of ULDCECT and DMSA-derived DRF (regression of near unity, Pearson's correlation coefficient of 0.72 ( p < 0.0001)).

Conclusion:

ULDCECT provides diagnostically accurate imaging in patients presenting with acute ureteric colic and significantly outperforms IVU for a comparable radiation burden. Use of ULDCECT instead of conventional CT-KUB may significantly reduce lifetime radiation exposure of ureteric colic patients without loss of diagnostic accuracy.
Direct visualization of the small hydrophobic protein of human respiratory syncytial virus reveals the structural basis for membrane permeability
Authors: Carter Stephen D. , Dent Kyle C. , Atkins Elizabeth , Foster Toshana L. , Verow Mark , Gorny Petra , Harris Mark , Hiscox Julian A. , Ranson Neil A. , Griffin Stephen , Barr John N.
Published: May 2010

MINT‐7890784, MINT‐7890776: SH (uniprotkb:P04852) and SH (uniprotkb:P04852) bind (MI:0407) by electron microscopy (MI:0040)
Insulin‐degrading enzyme antagonizes insulin‐dependent tissue growth and Aβ‐induced neurotoxicity in Drosophila
Authors: Tsuda Manabu , Kobayashi Toshikazu , Matsuo Takashi , Aigaki Toshiro
Published: May 2010

Insulin‐degrading enzyme (IDE) is implicated in the pathogenesis of type 2 diabetes mellitus (DM2) and Alzheimer's disease (AD). Here we provide genetic evidence that Drosophila Ide (dIde) antagonizes the insulin signaling pathway and human Aβ‐induced neurotoxicity in Drosophila. In this study, we also generated a dIde knockout mutant (dIde

KO
) by gene targeting, and found that loss of IDE increases the content of the major insect blood sugar, trehalose, thus suggesting a conserved role of IDE in sugar metabolism. Using dIde

KO
as a model, further investigations into the biological functions of IDE and its role in the pathogenesis of DM2 and AD can be made.
Anti-diabetic effects of lemon balm (Melissa officinalis) essential oil on glucose- and lipid-regulating enzymes in type 2 diabetic mice
Authors: Chung Mi Ja , Cho Sung-Yun , Bhuiyan Muhammad Javidul Haque , Kim Kyoung Heon , Lee Sung-Joon
Published: May 2010

The antioxidant activity of lemon balm (Melissa officinalis) essential oil (LBEO) on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and its hypoglycaemic effect indb/dbmice were investigated. LBEO scavenged 97 % of DPPH radicals at a 270-fold dilution. Mice administered LBEO (0·015 mg/d) for 6 weeks showed significantly reduced blood glucose (65 %;P < 0·05) and TAG concentrations, improved glucose tolerance, as assessed by an oral glucose tolerance test, and significantly higher serum insulin levels, compared with the control group. The hypoglycaemic mechanism of LBEO was further explored via gene and protein expression analyses using RT-PCR and Western blotting, respectively. Among all glucose metabolism-related genes studied, hepatic glucokinase and GLUT4, as well as adipocyte GLUT4, PPAR-γ, PPAR-α and SREBP-1c expression, were significantly up-regulated, whereas glucose-6-phosphatase and phosphoenolpyruvate carboxykinase expression was down-regulated in the livers of the LBEO group. The results further suggest that LBEO administered at low concentrations is an efficient hypoglycaemic agent, probably due to enhanced glucose uptake and metabolism in the liver and adipose tissue and the inhibition of gluconeogenesis in the liver.
The relative importance of socioeconomic indicators in explaining differences in BMI and waist:hip ratio, and the mediating effect of work control, dietary patterns and physical activity
Authors: Kjøllesdal Marte Råberg , Holmboe-Ottesen Gerd , Mosdøl Annhild , Wandel Margareta
Published: May 2010

Socioeconomic differences in overweight are well documented, but most studies have only used one or two indicators of socioeconomic position (SEP). The aim of the present study was to explore the relative importance of indicators of SEP (occupation, education and income) in explaining variation in BMI and waist:hip ratio (WHR), and the mediating effect of work control and lifestyle factors (dietary patterns, smoking and physical activity). The Oslo Health Study, a cross-sectional study, was carried out in 2000–1, Oslo, Norway. Our sample included 9235 adult working Oslo citizens, who attended a health examination and filled in two complementary FFQ with < 20 % missing responses to food items. Four dietary patterns were identified through factor analysis, and were named ‘modern’, ‘Western’, ‘traditional’ and ‘sweet’. In multivariate models, BMI and WHR were inversely associated with education (P < 0·001/P < 0·001) and occupation (P = 0·002/P < 0·001), whereas there were no significant associations with income or the work control. The ‘modern’ (P < 0·001) and the ‘sweet’ (P < 0·001) dietary patterns and physical activity level (P < 0·001) were inversely associated, while the ‘Western’ dietary pattern (P < 0·001) was positively associated with both BMI and WHR. These lifestyle factors could not fully explain the socioeconomic differences in BMI or WHR. However, together with socioeconomic factors, they explained more of the variation in WHR among men (21 %) than among women (7 %).
Prenatal mercury contamination: relationship with maternal seafood consumption during pregnancy and fetal growth in the ‘EDEN mother–child’ cohort
Authors: Drouillet-Pinard Peggy , Huel Guy , Slama R. , Forhan Anne , Sahuquillo J. , Goua Valérie , Thiébaugeorges Olivier , Foliguet Bernard , Magnin Guillaume , Kaminski Monique , Cordier Sylvaine , Charles Marie-Aline
Published: May 2010

Maternal seafood intake is of great health interest since it constitutes an important source of n-3 fatty acids, but provides also an important pathway for fetal exposure to Hg. The objective of the present study was to determine associations between Hg contamination and both maternal seafood consumption and fetal growth in French pregnant women. Pregnant women included in the ‘EDEN mother–child’ cohort study answered FFQ on their usual diet in the year before and during the last 3 months of pregnancy, from which frequencies of seafood intake were evaluated. Total hair-Hg level was determined for the first 691 included women. Associations between Hg level, seafood intake and several neonatal measurements were studied using linear regressions adjusted for confounding variables. The median Hg level for mothers was 0·52 μg/g. Maternal seafood intake was associated with Hg level (r 0·33; P < 0·0001). There was no association between Hg level and fetal growth in the whole sample of women, except for an early negative relationship with biparietal diameter. A positive association was found between seafood intake and fetal growth in overweight women only which remained unchanged after adjustment for Hg level (birth weight: +101 g for a difference of 1 sd in seafood consumption; P = 0·008). Although seafood intake was associated with Hg contamination in French pregnant women, the contamination level was low. There was no consistent association between Hg level and fetal growth. Taking into account Hg level did not modify associations between seafood intake and fetal growth.
Determination of thein vivoprebiotic potential of a maize-based whole grain breakfast cereal: a human feeding study
Authors: Carvalho-Wells Andrew L. , Helmolz Kathrin , Nodet Cecelia , Molzer Christine , Leonard Clare , McKevith Brigid , Thielecke Frank , Jackson Kim G. , Tuohy Kieran M.
Published: May 2010

Epidemiological studies have shown an inverse relationship between risk of CVD and intake of whole grain (WG)-rich food. Regular consumption of breakfast cereals can provide not only an increase in dietary WG but also improvements to cardiovascular health. Various mechanisms have been proposed, including prebiotic modulation of the colonic microbiota. In the present study, the prebiotic activity of a maize-derived WG cereal (WGM) was evaluated in a double-blind, placebo-controlled human feeding study (n32). For a period of 21 d, healthy men and women, mean age 32 (sd8) years and BMI 23·3 (sd0·58) kg/m2, consumed either 48 g/d WG cereal (WGM) or 48 g placebo cereal (non-whole grain (NWG)) in a crossover fashion. Faecal samples were collected at five points during the study on days 0, 21, 42, 63 and 84 (representing at baseline, after both treatments and both wash-out periods). Faecal bacteriology was assessed using fluorescencein situhybridisation with 16S rRNA oligonucleotide probes specific forBacteroidesspp.,Bifidobacteriumspp.,Clostridium histolyticum/perfringenssubgroup,Lactobacillus–Enterococcussubgroup and total bacteria. After 21 d consumption of WGM, mean group levels of faecal bifidobacteria increased significantly compared with the control cereal (P = 0·001). After a 3-week wash-out period, bifidobacterial levels returned to pre-intervention levels. No statistically significant changes were observed in serum lipids, glucose or measures of faecal output. In conclusion, this WG maize-enriched breakfast cereal mediated a bifidogenic modulation of the gut microbiota, indicating a possible prebiotic mode of action.
BEING IGBO AND MUSLIM: THE IGBO OF SOUTH-EASTERN NIGERIA AND CONVERSIONS TO ISLAM, 1930s TO RECENT TIMES
Authors: UCHENDU EGODI
Published: May 2010

Amid assumptions of a hegemonic Igbo Christian identity, conversions to Islam began in the late 1930s in the Igbo territory of south-east Nigeria – the only region in the country that was not touched by the nineteenth-century Islamic jihad and subsequent efforts to extend the borders of Islam in Nigeria. Four decades after the emergence of Islam in the Igbo homeland, and with the mixed blessings of a civil war, Igboland began to manifest clear evidence of indigenous Muslim presence. A key aspect of this article is how one can be both Igbo and Muslim. It considers the complex interplay of religious and ethnic identities of Igbo Muslims (including the mapping of religious values onto ethnic ones) until the 1990s, when Igbo Muslims began to disentangle ethnicity from religion, a development that owes much to the progress of Islamic education in Igboland and the emergence of Igbo Muslim scholars and clerics. Igbo reactions to conversions to Islam and the perceived threat of these conversions to Igbo Christian identity also receive some attention in this article.
MILITANTS, MOTHERS, AND THE NATIONAL FAMILY:UJAMAA, GENDER, AND RURAL DEVELOPMENT IN POSTCOLONIAL TANZANIA
Authors: LAL PRIYA
Published: May 2010

Between 1964 and 1975, development politics in Tanzania came to be organized around a version ofujamaathat normalized distinct gender roles and celebrated a generic ideal of the nuclear family. Yet asujamaavillagization unfolded on the ground in the south-eastern region of Mtwara, rural people's practices rarely conformed to the ideas about gender and family implicit in official discourse and policy. Just as the institution of the family on the ground proved to be a complicated and fractured one, the Tanzanian state's understanding of familyhood and the larger project ofujamaawere deeply riddled with internal tensions.
Viscous symmetric stability of circular flows
Authors: KLOOSTERZIEL R. C.
Published: May 2010

The linear stability properties of viscous circular flows in a rotating environment are studied with respect to symmetric perturbations. Through the use of an effective energy or Lyapunov functional, we derive sufficient conditions for Lyapunov stability with respect to such perturbations. For circular flows with swirl velocity V(r) we find that Lyapunov stability is determined by the properties of the function ℱ(r) = (2V/r + f)/Q (with f the Coriolis parameter, r the radius and Q the absolute vorticity) instead of the customary Rayleigh discriminant Φ(r) = (2V/r + f)Q. The conditions for stability are valid for flows with non-zero Q everywhere. Further, the flows are presumed stationary, incompressible and velocity perturbations are required to vanish at rigid boundaries. For Lyapunov stable flows an upper bound for the increase of the total perturbation energy due to transient non-modal growth is derived which is valid for any Reynolds number. The theory is applied to Couette flow and the Lamb–Oseen vortex.
Linear and nonlinear spatio-temporal instability in laminar two-layer flows
Authors: VALLURI P. , NÁRAIGH L. Ó , DING H. , SPELT P. D. M.
Published: May 2010

The linear and nonlinear spatio-temporal stability of an interface separating two Newtonian fluids in pressure-driven channel flow at moderate Reynolds numbers is analysed both theoretically and numerically. A linear, Orr–Sommerfeld-type analysis shows that most of such systems are unstable. The transition to an absolutely unstable regime is investigated, and is shown to occur in an intermediate range of Reynolds numbers and ratios of the thicknesses of the two layers, for near-density matched fluids with a viscosity contrast. A critical Reynolds number is found for transition from convective to absolute instability of relatively thin films. Results obtained from direct numerical simulations (DNSs) of the Navier–Stokes equations for long channels using a diffuse-interface method elucidate that waves generated by random noise at the inlet show that, near the inlet, waves are formed and amplified strongly, leading to ligament formation. Successive waves coalesce with each other further downstream, resulting in longer larger-amplitude waves further downstream. In the linearly absolute regime, the characteristics of the spatially growing wave near the inlet agree with that of the saddle point as predicted by the linear theory. The transition point from a convective to an absolute regime predicted by linear theory is also in agreement with a sharp change in the value of a healing length obtained from the DNSs.
‘State failure’ in theory and practice: the idea of the state and the contradictions of state formation
Authors: ERIKSEN STEIN SUNDSTØL
Published: May 2010

This article provides a critique of the discourse of ‘failed states’, and outlines an alternative approach. It is argued that by taking the model of the modern state for granted, and by analysing all states in terms of their degree of correspondence with or deviation from this ideal, this discourse does not help us understand the nature of the states in question, or the processes that lead to strong or weak states. Instead, the idea of the state should be treated as a category of practice and not as a category of analysis. Post-colonial state formation could then be analysed by focusing on the inter-relationship between the idea of the state and actual state practices, and on the ways that states have become linked to domestic society on the one hand and their relations with the external world on the other.
Future directions in Antarctic psychology research
Authors: Norris Kimberley , Paton Douglas , Ayton Jeff
Published: May 2010

Although existing research regarding the experience of Antarctic employment has primarily focused on the absence period (i.e. the period of time in which the expeditioner physically works in Antarctica), it has been repeatedly demonstrated that the majority of expeditioners experience positive outcomes associated with their time ‘on the ice’ despite transient (and frequently subclinical) physical, psychological, and social difficulties. Research strategies directed towards the individual experience of the expeditioner have not been able to fully account for the processes underpinning the adjustment processes that have facilitated seemingly resilient and growth outcomes. Similarly, insufficient research attention has been given to the separate phases of Antarctic employment, nor the potential interdependence between them, which may also provide further insight into these processes. To address these issues it has been argued that an approach incorporating individual, interpersonal, and organizational factors throughout the Antarctic employment experience, from pre-departure through absence, reunion, and reintegration, be adopted.
Brothels: outlaws or citizens?
Authors: Crofts Penny
Published: May 2010

Historically, sex services premises in New South Wales, Australia were regarded and regulated as illegal and disorderly entities; they were policed as outlaws. The Disorderly Houses Amendment Act 1995 [NSW] bestowed legal status, providing an opportunity to regulate sex services premises as legal subjects. Despite these reforms, in many areas brothels continue to be regulated more restrictively than other businesses. I argue that this is because, for many, brothels continue to be perceived as outlaws. They are regarded as inherently unlawful, disorderly, and hence warranting and requiring exclusion from the community. I argue that this conception of brothels as outlaws is constructed and reinforced through regulation. In contrast, some local councils and Land and Environment Court decisions have taken up the opportunity to regard and regulate sex services premises as legal subjects or citizens. The conception of sex services premises as citizen imports an existing legal framework, with associated accountabilities, rights and responsibilities. This shift in conception results in people viewing sex services premises differently, experiencing them differently and regulating them differently.
100‐year mass changes in the Swiss Alps linked to the Atlantic Multidecadal Oscillation
Authors: Huss Matthias , Hock Regine , Bauder Andreas , Funk Martin
Published: May 2010

Thirty new 100‐year records of glacier surface mass balance, accumulation and melt in the Swiss Alps are presented. The time series are based on a comprehensive set of field data and distributed modeling and provide insights into the glacier‐climate linkage. Considerable mass loss over the 20th century is evident for all glaciers, but rates differ strongly. Glacier mass loss shows multidecadal variations and was particularly rapid in the 1940s and since the 1980s. Mass balance is significantly anticorrelated to the Atlantic Multidecadal Oscillation (AMO) index assumed to be linked to thermohaline ocean circulation. We show that North Atlantic variability had a recognizable impact on glacier changes in the Swiss Alps for at least 250 years.
α‐Synuclein sequesters arachidonic acid to modulate SNARE‐mediated exocytosis
Authors: Darios Frédéric , Ruipérez Violeta , López Inmaculada , Villanueva Jose , Gutierrez Luis M , Davletov Bazbek
Published: May 2010

α‐Synuclein is a synaptic modulatory protein implicated in the pathogenesis of Parkinson disease. The precise functions of this small cytosolic protein are still under investigation. α‐Synuclein has been proposed to regulate soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (SNARE) proteins involved in vesicle fusion. Interestingly, α‐synuclein fails to interact with SNARE proteins in conventional protein‐binding assays, thus suggesting an indirect mode of action. As the structural and functional properties of both α‐synuclein and the SNARE proteins can be modified by arachidonic acid, a common lipid regulator, we analysed this possible tripartite link in detail. Here, we show that the ability of arachidonic acid to stimulate SNARE complex formation and exocytosis can be controlled by α‐synuclein, both in vitro and in vivo. α‐Synuclein sequesters arachidonic acid and thereby blocks the activation of SNAREs. Our data provide mechanistic insights into the action of α‐synuclein in the modulation of neurotransmission.
Does human imitate successful behaviors immediately?
Authors: Xu Zhao-Jin , Zhang Lian-Zhong
Published: May 2010

The emergence and abundance of cooperation in animal and human societies is a challenging puzzle to evolutionary biology. Over the past decades, various mechanisms have been suggested which are capable of supporting cooperation. Imitation dynamics, however, are the most representative microscopic rules of human behaviors on studying these mechanisms. Their standard procedure is to choose the agent to imitate at random from the population. In the spatial version this means a random agent from the neighborhood. Hence, imitation rules do not include the possibility to explore the available strategies, and then they have the possibility to reach a homogeneous state rapidly when the population size is small. To prevent evolution stopping, theorists allow for random mutations in addition to the imitation dynamics. Consequently, if the microscopic rules involve both imitation and mutation, the frequency of agents switching to the more successful strategy must be higher than that of them transiting to the same target strategy via mutation dynamics. Here we show experimentally that the frequency of switching to successful strategy approximates to that of mutating to the same strategy. This suggests that imitation might play an insignificant role on the behaviors of human decision making. In addition, our experiments show that the probabilities of agents mutating to different target strategies are significantly distinct. The actual mutation theories cannot give us an appropriate explanation to the experimental results. Hence, we argue that the mutation dynamics might have evolved for other reasons.
Convective dominated flows in open capillary channels
Authors: Rosendahl Uwe , Grah Aleksander , Dreyer Michael E.
Published: May 2010

This paper is concerned with convective dominated liquid flows in open capillary channels. The channels consist of two parallel plates bounded by free liquid surfaces along the open sides. In the case of steady flow the capillary pressure of the free surface balances the differential pressure between the liquid and the surrounding constant pressure gas phase. A maximum flow rate is achieved when the adjusted volumetric flow rate exceeds a certain limit leading to a collapse of the free surfaces. The convective dominated flow regime is a special case of open capillary flow, since the viscous forces are negligibly small compared with the convective forces. Flows of this type are of peculiar interest since the free surfaces possess a quasisymmetry in the flow direction. This quasisymmetry enables the application of a new effective method for evaluation of the flow limit. The flow limit is caused by a choking effect. This effect is indicated by the speed index, S, which is defined by the ratio of the flow velocity and the longitudinal capillary wave speed. The speed index is defined analogously to Mach number and tends toward unity in the case of flow limitation, i.e., when the maximum flow rate is reached. Utilizing the quasisymmetry, a new approach for a very precise determination of the speed index is presented. This approach uses a new approximation for the curvature of the surfaces by means of the empirical surface profiles. On the basis of empirical and theoretical data, the paper discusses the typical features of the stable flow. The experiments were performed under microgravity aboard the sounding rockets TEXUS 41 and TEXUS 42. The experiment setup enables the approach to the flow limit through either increase in flow rate or channel length. The theoretical data have been gained from numerical solutions of a one-dimensional flow model. The empirical and theoretical results are in good agreement and both confirm the choking effect as cause of the flow limitation. A general relation for the speed index as function of the flow rate and the channel length has been found which clarifies the fundamental behavior of the choking effect.
Dielectric, magnetic, and lattice dynamics properties of Y-type hexaferrite Ba0.5Sr1.5Zn2Fe12O22: Comparison of ceramics and single crystals
Authors: Kamba S. , Goian V. , Savinov M. , Buixaderas E. , Nuzhnyy D. , Maryško M. , Kempa M. , Bovtun V. , Hlinka J. , Knížek K. , Vaněk P. , Novák P. , Buršík J. , Hiraoka Y. , Kimura T. , Kouřil K. , Štěpánková H.
Published: May 2010

We prepared multiferroic Y-type hexaferrite Ba0.5Sr1.5Zn2Fe12O22 ceramics and compared their magnetic and dielectric properties with single crystal. Magnetic susceptibility and microwave resonance measurement revealed magnetic phase transition at TC=312 K, similar as in single crystal. Ferroelectric (FE) phase can be induced by external magnetic field in all investigated samples and the phase diagram in ceramics qualitatively resembles that of the single crystal. The range of magnetic fields, where the FE phase is induced, broadens after annealing of single crystal. Ceramics quenched after sintering exhibit several orders of magnitude lower conductivity than the single crystal. Heavily damped magnetic resonance was discovered in terahertz spectra at 10 K and its frequency softens below 5 GHz near TC. Number and symmetry of observed infrared (IR) and Raman active phonons correspond to paraelectric phase with D3d5 hexagonal structure. No evidence for a structural phase transition was found in the IR and Raman spectra on cooling (in zero magnetic field) or in the room-temperature IR spectra with external static magnetic field up to 0.3 T.
Ab initio calculation of band edges modified by (001) biaxial strain in group IIIA–VA and group IIB–VIA semiconductors: Application to quasiparticle energy levels of strained InAs/InP quantum dot
Authors: Kadantsev Eugene S. , Zielinski Michal , Korkusinski Marek , Hawrylak Pawel
Published: May 2010

Results of first-principles full potential calculations of absolute position of valence and conduction energy bands as a function of (001) biaxial strain are reported for group IIIA–VA (InAs, GaAs, InP) and group IIB–VIA (CdTe, ZnTe) semiconductors. Our computational procedure is based on the Kohn–Sham form of density functional theory (KS DFT), local spin density approximation (LSDA), variational treatment of spin-orbital coupling, and augmented plane wave plus local orbitals method (APW+lo). The band energies are evaluated at lattice constants obtained from KS DFT total energy as well as from elastic free energy. The conduction band energies are corrected with a rigid shift to account for the LSDA band gap error. The dependence of band energies on strain is fitted to polynomial of third degree and results are available for parameterization of biaxial strain coupling in empirical tight-binding models of IIIA–VA and IIB–VIA self-assembled quantum dots (SAQDs). The strain effects on the quasiparticle energy levels of InAs/InP SAQD are illustrated with empirical atomistic tight-binding calculations.
Babinet’s principle and the band structure of surface waves on patterned metal arrays
Authors: Edmunds J. D. , Taylor M. C. , Hibbins A. P. , Sambles J. R. , Youngs I. J.
Published: May 2010

The microwave response of an array of square metal patches and its complementary structure, an array of square holes, has been experimentally studied. The resonant phenomena, which yield either enhanced transmission or reflection, are attributed to the excitation of diffractively coupled surface waves. The band structure of these surface modes has been quantified for both p-(transverse magnetic) and s-(transverse electric) polarized radiation and is found to be dependent on the periodicity of the electric and magnetic fields on resonance. The results are in excellent accord with predictions from finite element method modeling and the electromagnetic form of Babinet’s principle [Babinet, C. R. Acad. Sci. 4, 638 (1837)].
Visualizing water molecule distribution by atomic force microscopy
Authors: Kimura Kenjiro , Ido Shinichiro , Oyabu Noriaki , Kobayashi Kei , Hirata Yoshiki , Imai Takashi , Yamada Hirofumi
Published: May 2010

Hydration structures at biomolecular surfaces are essential for understanding the mechanisms of the various biofunctions and stability of biomolecules. Here, we demonstrate the measurement of local hydration structures using an atomic force microscopy system equipped with a low-noise deflection sensor. We applied this method to the analysis of the muscovite mica/water interface and succeeded in visualizing a hydration structure that is site-specific on a crystal. Furthermore, at the biomolecule/buffer solution interface, we found surface hydration layers that are more packed than those at the muscovite mica/water interface.
Current-interchange tearing modes: Conversion of interchange-type modes to tearing modes
Authors: Zheng L. J. , Furukawa M.
Published: May 2010

It is shown that, in addition to usual neoclassical tearing modes, another type of nonclassical tearing mode exists in tokamaks: viz., current-interchange tearing modes (CITMs). CITMs are directly driven by unstable pressure-driven electromagnetic or electrostatic modes of the interchange type (e.g., interchange/ballooning modes, drift waves, etc.) due to the current gradient in tokamaks. Interchange-type modes exchange not only thermal and magnetic energies between flux tubes but also current. In a plasma with a current (or resistivity) gradient, such an interchange can create a current sheet at a mode resonance surface and result in the excitation of CITMs. Note that the interchange mode (i.e., Rayleigh–Taylor instability) is fundamental to tokamak physics. This new theory has an effect on both resistive magnetohydrodynamic stability and transport theories. Instabilities of the interchange type could be directly converted into CITMs, alternative to forming turbulent eddies through nonlinear coupling as in conventional transport theories. In particular, our CITM theory fills in the component in the transport theory of Rechester and Rosenbluth [Phys. Rev. Lett. 40, 38 (1978)] for the origin of magnetic island structure in axisymmetric tokamaks.
Theoretical predictions of trends in spectroscopic properties of homonuclear dimers and volatility of the 7p elements
Authors: Pershina V. , Borschevsky A. , Anton J. , Jacob T.
Published: May 2010

Fully relativistic density functional theory electronic structure calculations were performed for homonuclear dimers of the 7p elements, 113–118 and their 6p homologs, Tl through Rn. All the dimers of the heaviest elements, with the exception of (118)2, were found to be weaker bound than their lighter homologs. The difference in the dissociation energy (De) between the 6p and 7p homologs was shown to decrease from group 15 to group 17, with a reversal of the trend in group 18. A remarkable feature is a shift of the maximum in De(M2) from group 15 in the third through sixth rows to group 16 in the seventh row. Strong relativistic effects on the 7p atomic orbitals, particularly, their large spin-orbit splitting, were shown to be responsible for these trends. Using the calculated De(M2), the sublimation enthalpies, ΔHsub, of macroamounts, or formation enthalpies of gaseous atoms, ΔHf(g), of the heaviest elements were estimated using a linear correlation between these quantities in the chemical groups. The newly estimated values are in good agreement with those obtained via a linear extrapolation from the lighter homologs in the groups.
Quantum solvent states and rovibrational spectra of small doped H3e clusters through the full-configuration-interaction nuclear orbital approach: The (H3e)N–Cl2(X) case (N≤4)
Authors: de Lara-Castells María Pilar , Aguirre Néstor F. , Villarreal Pablo , Barrio Gerardo Delgado , Mitrushchenkov Alexander O.
Published: May 2010

A full-configuration-interaction nuclear orbital treatment has been recently developed as a benchmark quantum-chemistry-like method to study small doped H3e clusters [M. P. de Lara-Castells et al., J. Chem. Phys. 125, 221101 (2006)]. Our objective in this paper is to extend our previous study on (H3e)N–Cl2(B) clusters, using an enhanced implementation that allows employing very large one-particle basis sets [M. P. de Lara-Castells et al., J. Chem. Phys. 131, 194101 (2009)], and apply the method to the (H3e)N–Cl2(X) case, using both a semiempirical T-shaped and an ab initio He-dopant potential with minima at both T-shaped and linear conformations. Calculations of the ground and low-lying excited solvent states stress the key role played by the anisotropy of the He-dopant interaction in determining the global energies and the structuring of the H3e atoms around the dopant. Whereas H3e atoms are localized in a broad belt around the molecular axis in ground-state N-sized complexes with N=1–3, irrespective of using the T-shaped or the ab initio He-dopant potential function, the dopant species becomes fully coated by just four H3e atoms when the He-dopant potential also has a minimum at linear configurations. However, excited solvent states with a central ring-type clustering of the host molecule are found to be very close in energy with the ground state by using the ab initio potential function. A microscopic analysis of this behavior is provided. Additional simulations of the molecular rovibrational Raman spectra, also including excited solvent states, provide further insights into the importance of proper modeling the anisotropy of the He-dopant interaction in these weakly bound systems and of taking into account the low-lying excitations.
The electronic states of SeF: A reinterpretation of the chemiluminescent emission of the reaction of selenium with fluorine
Authors: Hermoso Willian , Ornellas Fernando R.
Published: May 2010

The low-lying doublet and quartet electronic states of the species SeF correlating with the first dissociation channel are investigated theoretically at a high-level of electronic correlation treatment, namely, the complete active space self-consistent field/multireference single and double excitations configuration interaction (CASSCF/MRSDCI) using a quintuple-zeta quality basis set including a relativistic effective core potential for the selenium atom. Potential energy curves for (Λ+S) states and the corresponding spectroscopic properties are derived that allows for an unambiguous assignment of the only spectrum known experimentally as due to a spin-forbidden X Π2−a ∑4− transition, and not a A Π2−X Π2 transition as assumed so far. For the bound excited doublets, yet unknown experimentally, this study is the first theoretical characterization of their spectroscopic properties. Also the spin-orbit coupling constant function for the X Π2 state is derived as well as the spin-orbit coupling matrix element between the X Π2 and a ∑4− states. Dipole moment functions and vibrationally averaged dipole moments show SeF to be a very polar species. An overview of the lowest-lying spin-orbit (Ω) states completes this description.
Graphene morphology regulated by nanowires patterned in parallel on a substrate surface
Authors: Zhang Zhao , Li Teng
Published: May 2010

The graphene morphology regulated by nanowires patterned in parallel on a substrate surface is quantitatively determined using energy minimization. The regulated graphene morphology is shown to be governed by the nanowire diameter, the nanowire spacing, and the interfacial bonding energies between the graphene and the underlying nanowires and substrate. We demonstrate two representative regulated graphene morphologies and determine critical values of the nanowire spacing, nanowire diameter, and interfacial bonding energies at which graphene switches between the two representative morphologies. Interestingly, we identify a rule-of-thumb formula that correlates the critical nanowire spacing, the critical interfacial bonding energies and the nanowire diameter in quite well agreement with the full-scale simulation results. Results from the present study offer guidelines in nanostructural design to achieve desired graphene morphology via regulation with a resolution approaching the atomic feature size of graphene.
Mapping of magnetic anisotropy in strained ferromagnetic semiconductor GaMnAs films
Authors: Kim Shinhee , Lee Hakjoon , Yoo Taehee , Lee Sangyeop , Lee Sanghoon , Liu X. , Furdyna J. K.
Published: May 2010

The effect of strain on the magnetic anisotropy of GaMnAs films has been systematically investigated using Hall effect measurements. The magnitude of the strain, which was caused by differences in the lattice constant between the GaMnAs film and buffer layer, was controlled by adjustment of the alloy composition in the GaInAs buffer layer. The in-plane and out-of-plane components of the magnetic anisotropy were obtained from the angular dependence of the planar Hall resistance and the anomalous Hall resistance, respectively. The anisotropy constants obtained allow us to construct a three-dimensional magnetic free energy surface, which provides a clear understanding of the transition behavior of the magnetization between the in-plane and out-of-plane direction in the GaMnAs films.