bluuebunny/crossref_metadata_2025 huggingface dataset:
Demethylation of Epiregulin Gene by Histone Demethylase FBXL11 and BCL6 Corepressor Inhibits Osteo/dentinogenic Differentiation
Authors: Du Juan , Ma Yushi , Ma Ping , Wang Songlin , Fan Zhipeng
Published: October 2012

Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. Histone methylation, controlled by histone methyltransferases and demethylases, may play a key role in MSC differentiation. Here, we investigated FBXL11, a histone demethylase, lysine (K)-specific demethylase 2A, which is evolutionarily conserved, ubiquitously expressed, and a member of the JmjC-domain-containing histone demethylase family. We tested whether FBXL11 could inhibit the osteo/dentinogenic differentiation potential in MSC cells with gain- and loss-of-function assays. We found that FBXL11 regulated osteo/dentinogenic differentiation in MSC cells. Furthermore, we found that the gene encoding the epidermal growth factor, Epiregulin (EREG), was a downstream target of FBXL11, and that EREG mediated FBXL11 regulation of MSC differentiation. Moreover, we found that the FBXL11 histone demethylase function was activated by associating with BCL6 corepressor, and this complex could repress EREG transcription by increasing histone K4/36 methylation in the EREG promoter. In conclusion, our results elucidated a new function for FBXL11 and EREG, explored the molecular mechanism underlying directed differentiation in MSC cells, and identified potential target genes for improving tissue regeneration techniques.
An algorithmic solution for computing circle intersection areas and its applications to wireless communications
Authors: Librino Federico , Levorato Marco , Zorzi Michele
Published: October 2012

A novel iterative algorithm for the efficient computation of the intersection areas of an arbitrary number of circles is presented. The algorithm, on the basis of a trellis structure, hinges on two geometric results, which allow the existence check and the computation of the area of the intersection regions generated by more than three circles by simple algebraic manipulations of the intersection areas of a smaller number of circles. The presented algorithm is a powerful tool for the performance analysis of wireless networks and finds many applications, ranging from sensor to cellular networks. As an example of practical application, an insightful study of the uplink outage probability in a wireless network with cooperative access points as a function of the transmission power and access point density is presented. Copyright © 2012 John Wiley & Sons, Ltd.
Near wake Reynolds‐averaged Navier–Stokes predictions of the wake behind the MEXICO rotor in axial and yawed flow conditions
Authors: Sørensen Niels N. , Bechmann A. , Réthoré P‐E. , Zahle F.
Published: October 2012

In the present paper, Reynolds‐averaged Navier–Stokes predictions of the flow field around the MEXICO rotor in yawed conditions are compared with measurements. The paper illustrates the high degree of qualitative and quantitative agreement that can be obtained for this highly unsteady flow situation, by comparing measured and computed velocity profiles for all three Cartesian velocity components along four axial transects and several radial transects. Copyright © 2012 John Wiley & Sons, Ltd.
Short‐term extreme response analysis of a jacket supporting an offshore wind turbine
Authors: Saha Nilanjan , Gao Zhen , Moan Torgeir , Naess Arvid
Published: October 2012

Wind turbines must be designed in such a way that they can survive in extreme environmental conditions. Therefore, it is important to accurately estimate the extreme design loads. This paper deals with a recently proposed method for obtaining short‐term extreme values for the dynamic responses of offshore fixed wind turbines. The 5 MW NREL wind turbine is mounted on a jacket structure (92 m high) at a water depth of 70 m at a northern offshore site in the North Sea. The hub height is 67 m above tower base or top of the jacket, i.e. 89 m above mean water level. The turbine response is numerically obtained by using the aerodynamic software HAWC2 and the hydrodynamic softwareUSFOS. Two critical responses are discussed, the base shear force and the bending moment at the bottom of the jacket. The extreme structural responses are considered for wave‐induced and wind‐induced loads for a 100 year return‐period harsh metocean condition with a 14.0 m significant wave height, a 16 s peak spectral period, a 50 m s − 1(10 min average) wind speed (at the hub) and a turbulence intensity of 0.1 for a parked wind turbine. After performing the 10 min nonlinear dynamic simulations, a recently proposed extrapolation method is used for obtaining the extreme values of those responses over a period of 3 h. The sensitivity of the extremes to sample size is also studied. The extreme value statistics are estimated from the empirical mean upcrossing rates. This method together with other frequently used methods (i.e. the Weibull tail method and the global maxima method) is compared with the 3 h extreme values obtained directly from the time‐domain simulations. Copyright © 2012 John Wiley & Sons, Ltd.
A spinner‐integrated wind lidar for enhanced wind turbine control
Authors: Mikkelsen T. , Angelou N. , Hansen K. , Sjöholm M. , Harris M. , Slinger C. , Hadley P. , Scullion R. , Ellis G. , Vives G.
Published: October 2012

A field test with a continuous wave wind lidar (ZephIR) installed in the rotating spinner of a wind turbine for unimpeded preview measurements of the upwind approaching wind conditions is described. The experimental setup with the wind lidar on the tip of the rotating spinner of a large 80 m rotor diameter, 59 m hub height 2.3 MW wind turbine (Vestas NM80), located at Tjæreborg Enge in western Denmark is presented. Preview wind data at two selected upwind measurement distances, acquired during two measurement periods of different wind speed and atmospheric stability conditions, are analyzed. The lidar‐measured speed, shear and direction of the wind field previewed in front of the turbine are compared with reference measurements from an adjacent met mast and also with the speed and direction measurements on top of the nacelle behind the rotor plane used by the wind turbine itself. Yaw alignment of the wind turbine based on the spinner lidar measurements is compared with wind direction measurements from both the nearby reference met mast and the turbine's own yaw alignment wind vane. Furthermore, the ability to detect vertical wind shear and vertical direction veer in the inflow, through the analysis of the spinner lidar data, is investigated. Finally, the potential for enhancing turbine control and performance based on wind lidar preview measurements in combination with feed‐forward enabled turbine controllers is discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Connections between chromatin signatures and splicing
Authors: Gómez Acuña Luciana I. , Fiszbein Ana , Alló Mariano , Schor Ignacio E. , Kornblihtt Alberto R.
Published: October 2012

Splicing and alternative splicing are involved in the expression of most human genes, playing key roles in differentiation, cell cycle progression, and development. Misregulation of splicing is frequently associated to disease, which imposes a better understanding of the mechanisms underlying splicing regulation. Accumulated evidence suggests that multiple trans‐acting factors and cis‐regulatory elements act together to determine tissue‐specific splicing patterns. Besides, as splicing is often cotranscriptional, a complex picture emerges in which splicing regulation not only depends on the balance of splicing factor binding to their pre‐mRNA target sites but also on transcription‐associated features such as protein recruitment to the transcribing machinery and elongation kinetics. Adding more complexity to the splicing regulation network, recent evidence shows that chromatin structure is another layer of regulation that may act through various mechanisms. These span from regulation of RNA polymerase II elongation, which ultimately determines splicing decisions, to splicing factor recruitment by specific histone marks. Chromatin may not only be involved in alternative splicing regulation but in constitutive exon recognition as well. Moreover, splicing was found to be necessary for the proper ‘writing’ of particular chromatin signatures, giving further mechanistic support to functional interconnections between splicing, transcription and chromatin structure. These links between chromatin configuration and splicing raise the intriguing possibility of the existence of a memory for splicing patterns to be inherited through epigenetic modifications. WIREs RNA 2013, 4:77–91. doi: 10.1002/wrna.1142

This article is categorized under:

RNA Processing > Splicing Mechanisms

RNA Processing > Splicing Regulation/Alternative Splicing
Insensitizing controls for the Navier–Stokes equations
Authors: Gueye Mamadou
Published: October 2012

In this paper, we deal with the existence of insensitizing controls for the Navier–Stokes equations in a bounded domain with Dirichlet boundary conditions. We prove that there exist controls insensitizing the

L^{2}

-norm of the observation of the solution in an open subset

\mathcalO}

of the domain, under suitable assumptions on the data. This problem is equivalent to an exact controllability result for a cascade system. First we prove a global Carleman inequality for the linearized Navier–Stokes system with right-hand side, which leads to the null controllability at any time

T > 0

. Then, we deduce a local null controllability result for the cascade system.
Effect of ghrelin on inflammatory response in lung contusion
Authors: Guven Berrak , Gokce Mertol , Saydam Ozkan , Can Murat , Bektas Sibel , Yurtlu Serhan
Published: October 2012

The purpose of this study was to investigate the effects of ghrelin on inflammatory response and tissue damage following trauma‐induced acute lung injury. Thirty male wistar albino rats (300–400 g) were randomly assigned into three groups: control group (n = 6), lung contusion plus saline (saline‐treated, n = 12), and lung contusion plus ghrelin (ghrelin‐treated, n = 12). Saline‐ or ghrelin‐treated traumatic rats were sacrificed at two time points (24 and 72 hours) after lung contusion. Blood was collected for the analysis of serum adenosine deaminase (ADA). Tissue transforming growth factor‐beta 1 (TGF‐β1) and matrix metalloproteinase‐2 (MMP‐2) levels were measured by enzyme‐linked immunosorbent assay and histopathological examination was performed on the lung tissue samples. Our results indicated that ghrelin significantly reduced morphologic damages. Serum ADA activities were significantly decreased after lung contusion and this decline started early with ghrelin treatment. TGF‐β1 and MMP‐2 levels in lung tissue were elevated at 72 hours after lung contusion and treatment with ghrelin significantly increased TGF‐β1 level and reduced MMP‐2 level. In conclusion, our study demonstrates that acute lung injury initiated proinflammatory responses and ghrelin administration showed an anti‐inflammatory effect in lung contusion.
Customer Order Flow, Intermediaries, and Discovery of the Equilibrium Risk-Free Rate
Authors: Menkveld Albert J. , Sarkar Asani , Wel Michel van der
Published: October 2012

Macro announcements change the equilibrium risk-free rate. We find that Treasury prices reflect part of the impact instantaneously, but intermediaries rely on their customer order flow after the announcement to discover the full impact. This customer flow informativeness is strongest when analyst macro forecasts are most dispersed. The result holds for 30-year Treasury futures trading in both electronic and open-outcry markets. We further show that intermediaries benefit from privately recognizing informed customer flow, as their own-account trading profitability correlates with customer order access.
Are CFOs’ Trades More Informative Than CEOs’ Trades?
Authors: Wang Weimin , Shin Yong-Chul , Francis Bill B.
Published: October 2012

We investigate whether trades made by chief financial officers (CFOs) reveal more information about future stock returns than those by chief executive officers (CEOs). We find that CFOs earn statistically and economically higher abnormal returns following their purchases of company shares than CEOs. During 1992–2002, CFOs earned an average 12-month excess return that is 5% higher than that by CEOs. The superior performance by CFOs occurs notwithstanding controls for risk factors and persists even after their trades are publicly disclosed. Further analysis shows that CFO purchases are associated with more positive future earnings surprises than CEO purchases, suggesting that CFOs incorporate better information about future earnings.
Gastrointestinal nematodes of the lizardTropidurus hispidus(Squamata: Tropiduridae) from a semi-arid region of north-eastern Brazil
Authors: Anjos L.A. , Ávila R.W. , Ribeiro S.C. , Almeida W.O. , da Silva R.J.
Published: October 2012

The tropidurid lizardTropidurus hispidushas a wide distribution in South America. However, knowledge about its helminth fauna is patchy and has been reported for only a few localities along its range of distribution. This study presents data on helminth fauna composition and parameters of infection for a population ofT. hispidusfrom an area within the Brazilian Caatinga biome (semi-arid physiognomy). We found five nematode species within the gastrointestinal tract of lizards:Parapharyngodonsceleratus(Pharyngodonidae);Physalopteralutzi,PhysalopteraretusaandPhysalopteroidesvenancioi(Physalopteridae); andStrongylurisoscari(Heterakidae). The overall prevalence was 84.2% and the mean intensity of infection was 8.5 ± 1.1. The body size of adult male lizards influenced positively the intensity of infection. The infracommunities of nematodes presented an intermediate aggregated distribution (discrepancy index;D= 0.519) and a depauperate nematode fauna. The presence of generalist parasite species has contributed to an increase in the overall richness of the component community. This sampled host population presented the highest prevalence of parasites compared with other studies onT. hispidus, but their relatively low richness can be related to the disturbed environment of the study area.
Molecular characterization of Portuguese populations of the pinewood nematodeBursaphelenchus xylophilususing cytochromeband cellulase genes
Authors: Valadas V. , Laranjo M. , Mota M. , Oliveira S.
Published: October 2012

Bursaphelenchus xylophilusis the causal agent of pine wilt disease and a worldwide pest with high economic impact. Since its first diagnosis in Portugal in 1999, it has been subjected to quarantine measures with impact on forest health and ecosystem stability, significantly affecting international trade of wood products. The disease was detected in the north and centre of continental Portugal and, since 2008, the whole country has been considered an affected area. Recently, it was detected in Madeira Island. In order to avoid new outbreaks, it has become of major importance to understand the patterns of spread, introduction points and to characterize the new populations from continental Portugal and Madeira Island. Mitochondrial cytochromeb(cytb) and parasitic cellulase gene sequences were used to evaluate the genetic relationships among isolates that could indicate possible origins of the new outbreaks. Portuguese isolates were compared with isolates from USA, China, Japan and South Korea, in order to investigate possible infection pathways and disease spread patterns in Portugal. Phylogenetic trees based on both genes show that Portuguese isolates group with Asian isolates. Isolates from USA are in a separate position in both gene trees. However, the phylogenetic tree based on the cellulase gene sequences shows higher differentiation among Portuguese isolates than that ofcytb.These results agree with those previously obtained using inter-simple sequence repeats (ISSR). This was the first study to usecytband cellulase genes to characterize pinewood nematode (PWN) populations. This study suggests that cellulase is a better marker thancytbto study genetic diversity inB. xylophilus.
Image-guided sinus surgery: practical and financial experiences from a UK centre 2001–2009
Authors: Masterson L , Agalato E , Pearson C
Published: October 2012

Background:

Image guidance surgery is an emerging technology that may allow more efficient treatment of sinus disease. This retrospective study examines National Health Service and military patients who underwent procedures using image guidance surgery during the period 2001–2009.

Methods:

Medical records were reviewed in terms of indications for surgery, incidence of major complications and need for revision following image guidance surgery. An attempt was also made to determine the cost-effectiveness of purchasing this navigational system.

Results:

A total of 132 patients underwent 147 procedures using image guidance surgery over the 8-year period. The indications for surgery ranged from severe nasal polyposis and chronic rhinosinusitis to malignant tumours in the paranasal sinus and skull base region. Average length of follow up was 17.6 months. Four patients had a major complication. Fourteen patients underwent revision surgery. The cost of providing an image guidance surgery service was estimated to be £110,000–120,000 during the study period. The economic model for the subgroup of nineteen military patients (with non-polypoid chronic rhinosinusitis) suggests that use of this technology will reduce overall costs by approximately £70,000 when compared with conventional sinus surgery.

Conclusion:

This study provides some evidence that image-guided sinus surgery is cost effective, safe and may decrease surgical revision rates.
Bryoria rigida, a new Asian lichen species from the Himalayan region
Authors: JØRGENSEN Per M. , MYLLYS Leena , VELMALA Saara , WANG Li-Song
Published: October 2012

Molecular studies have revealed the presence of yet another species in the Bryoria bicolor complex in China, which confirms that the mountains of SE Asia to be an evolutionary centre for Bryoria sect. Divaricatae. The new species B. rigida is formally described. It is characterized by a stiff and coarse thallus, which contains fumarprotocetraric acid and often protocetraric acid as the main substances. A key to the divaricate species of Bryoria in the Himalayan region is provided.
Exploring Perceptions of “Wellness” in Black Ethnic Minority Individuals at Risk of Developing Psychosis
Authors: Codjoe Louisa , Byrne Majella , Lister Matthew , McGuire Philip , Valmaggia Lucia
Published: October 2012

Background:The NICE Schizophrenia guidelines (NICE, 2009, Update) recommend that services should address cultural differences in treatment, expectations and adherence, and clients’ explanatory models of illness should be better understood. Service users from Black African and Black Caribbean communities are overrepresented in psychosis services in the UK, yet there is no literature on how wellness is understood by this group.Aims:This study explored perceptions of wellness in Black African and Black Caribbean individuals with an At Risk Mental State (ARMS) for psychosis.Method:A Q set of potential meanings of wellness was identified from a literature search and interviews with people at risk of developing psychosis. From this, 50 potential definitions were identified; twenty Black African and Black Caribbean ARMS clients ranked these definitions.Results:Following factor analysis of completed Q sorts, six factors emerged that offered insight into perceptions of wellness in this population. These factors included: sense of social purpose explanation, the surviving God's test explanation, the internalization of spirituality explanation, understanding and attribution of symptoms to witchcraft explanation, avoidance and adversity explanation, and seeking help to cope explanation.Conclusions:Although preliminary, differences between the factors suggests that there may be perceptions of wellness specific to these groups that are distinct from the medical view of wellness promoted within early detection services. These differences may potentially impact upon engagement, particularly factors that clients feel may facilitate or aide their recovery. It is suggested that these differences need to be considered as part of the assessment and formulation process.
Redefining the deviance objective for generalised linear models
Authors: Lovick A. C. , Lee P. K. W.
Published: October 2012

This paper defines the ‘Case Deleted’ Deviance - a new objective function for evaluating Generalised Linear Models, and applies this to a number of practical examples in the pricing of general insurance. The paper details practical approximations to enable the efficient calculation of the objective, and derives modifications to the standard Generalised Linear Modelling algorithm to allow the derivation of scaled parameters from this measure to reduce potential over fitting to historical data. These scaled parameters improve the predictiveness of the model when applied to previously unseen data points, the most likely being related to future business written. The potential for over fitting has increased due to number of factors now used, particularly in pricing personal lines business and the advent of price comparison sites which has increased the penalties of mis-estimation. New material in this paper has been included in a UK patent application No. 1020091.3.
Can differences in physical activity by socio-economic status in European adolescents be explained by differences in psychosocial correlates? A mediation analysis within the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study
Authors: De Cocker Katrien , Artero Enrique G , De Henauw Stefaan , Dietrich Sabine , Gottrand Frédéric , Béghin Laurent , Hagströmer Maria , Sjöström Michael , Plada Maria , Manios Yannis , Mauro Beatrice , Molnár Dénes , Moreno Luis A , Ottevaere Charlene , Valtueña Jara , Maes Lea , De Bourdeaudhuij Ilse
Published: October 2012

Objective

Socio-economic status (SES) has been positively associated with physical activity (PA) levels in adolescents. In order to tackle these social inequalities, information is needed about the underlying mechanisms of this association. The present study aimed to investigate the potential mediating role of psychosocial correlates of PA on the relationship between SES and PA in European adolescents.

Design

Cross-sectional study testing the mediating role of psychosocial correlates in the SES–PA association using the product-of-coefficients test of MacKinnon.

Setting

Ten European cities in nine different countries, the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.

Subjects

Adolescents (n 2780) aged 12·5–17·49 years self-reported on PA (moderate-to-vigorous intensity PA and total PA), SES indicators (education of the mother and Family Affluence Scale) and psychosocial correlates of PA (stage of change, attitudes, awareness, modelling, social support, self-efficacy, benefits, barriers and environmental correlates).

Results

SES (Family Affluence Scale) was significantly associated with moderate-to-vigorous intensity PA. According to single-mediator models, this association was significantly mediated by stage of change (t = 3·6, P ≤ 0·001), awareness (t = 2·7, 0·001 < P ≤ 0·01), modelling (t = 4·8, P ≤ 0·001), self-efficacy (t = 2·5, 0·01<P ≤ 0·05), barriers (t = 2·7, 0·001 < P ≤ 0·01) and environmental (t = 3·0, 0·001 < P ≤ 0·01) correlates of PA. The multiple-mediators model showed that the mediating role of the combination of these psychosocial correlates was also significant (t = 6·2, P ≤ 0·001).

Conclusions

Adolescents with low family wealth scored lower on stage of change, awareness, modelling, self-efficacy and environmental correlates of PA, and higher on PA barriers, which in turn resulted in lower levels of moderate-to-vigorous PA. Future interventions should target these individual and environmental constructs in order to tackle and intervene on social inequalities in PA among adolescents.
Schopenhauer, Kant and Compassion
Authors: Guyer Paul
Published: October 2012

Schopenhauer presents his moral philosophy as diametrically opposed to that of Kant: for him, pure practical reason is an illusion and morality can arise only from the feeling of compassion, while for Kant it cannot be based on such a feeling and can be based only on pure practical reason. But the difference is not as great as Schopenhauer makes it seem, because for him compassion is supposed to arise from metaphysical insight into the unity of all being, thus from pure if theoretical reason, while for Kant pure practical reason works only by effecting a feeling of respect (in the ‘Critical’ works) or by cultivating, i.e. affecting, natural dispositions to moral feeling (in the ‘post-Critical’ works). I argue that Kant's is the more realistic theory on this point.
Schopenhauer's Transformation of the Kantian Sublime
Authors: Shapshay Sandra
Published: October 2012

Schopenhauer singles out Kant's theory of the sublime for high praise, calling it ‘by far the most excellent thing in the Critique of Aesthetic Judgement’, yet, in his main discussion of the sublime, he ridicules Kant's explanation as being in the grip of scholastic metaphysics. My first aim in this paper is to sort out Schopenhauer's apparently conflicted appraisal of Kant's theory of the sublime. Next, based on hisNachlaß,close readings of published texts and especially of his account of the experience of tragic drama, I offer a reconstruction of Schopenhauer's theory of the sublime which understands it – against prevailing scholarly views – as atransformation ofrather than as a realdeparture fromthe Kantian explanation. Finally, I suggest that my interpretation of Schopenhauer's theory of the sublime has far-reaching consequences for a proper understanding of his views on freedom.
Direct Observations of Confined Layer Slip in Cu/Nb Multilayers
Authors: Li Nan , Wang Jian , Misra Amit , Huang Jian Yu
Published: October 2012

In situ nanoindentation of a 30 nm Cu/20 nm Nb multilayer film in a transmission electron microscope revealed confined layer slip as the dominant deformation mechanism. Dislocations were observed to nucleate from the Cu-Nb interfaces in both layers. Dislocation glide was confined by interfaces to occur within each layer, without transmission across interfaces. Cu and Nb layers co-deformed to large plastic strains without cracking. These microscopy observations provide insights in the unit mechanisms of deformation, work hardening, and recovery in nanoscale metallic multilayers.
Role of α7- and α4β2-nAChRs in the neuroprotective effect of nicotine in stress-induced impairment of hippocampus-dependent memory
Authors: Alzoubi Karem H. , Srivareerat Marisa , Tran Trinh T. , Alkadhi Karim A.
Published: October 2012

We have previously shown that nicotine prevents stress-induced memory impairment. In this study, we have investigated the role of α7- and α4β2-nicotinic acetylcholine receptors (nAChRs) in the protective effect of nicotine during chronic stress conditions. Chronic psychosocial stress was induced using a form of rat intruder model. During stress, specific antagonist for either α7-nAChRs [methyllycaconitine (MLA)] or α4β2-nAChRs [dihydro-β-erythroidine (DHβE)] was infused into the hippocampus using a 4-wk osmotic pump at a rate of 82 µg/side.d and 41 µg/side.d, respectively. Three weeks after the start of infusion, all rats were subjected to a series of cognitive tests in the radial arm water maze (RAWM) for six consecutive days or until the animal reached days to criterion (DTC) in the fourth acquisition trial and in all memory tests. DTC is defined as the number of days the animal takes to make no more than one error in three consecutive days. In the short-term memory test, MLA-infused stressed/nicotine-treated rats made similar errors to those of stress and significantly more errors compared to those of stress/nicotine, nicotine or control groups. This finding was supported by the DTC values for the short memory tests. Thus, MLA treatment blocked the neuroprotective effect of nicotine during chronic stress. In contrast, DHβE infusion did not affect the RAWM performance of stress/nicotine animals. These results strongly suggest the involvement of α7-nAChRs, but not α4β2-nAChRs, in the neuroprotective effect of chronic nicotine treatment during chronic stress conditions.
Disruption of prefrontal cortical–hippocampal balance in a developmental model of schizophrenia: reversal by sulpiride
Authors: Belujon Pauline , Patton Mary H. , Grace Anthony A.
Published: October 2012

The nucleus accumbens (NAc) receives converging inputs from the medial prefrontal cortex (mPFC) and the hippocampus which have competitive interactions in the NAc to influence motivational drive. We have previously shown altered synaptic plasticity in the hippocampal–NAc pathway in the methylazoxymethanol acetate (MAM) developmental model of schizophrenia in rodents that is dependent on cortical inputs. Thus, because mPFC–hippocampal balance is known to be partially altered in this model, we investigated potential pathological changes in the hippocampal influence over cortex-driven NAc spike activity. Here we show that the reciprocal interaction between the hippocampus and mPFC is absent in MAM animals but is able to be reinstated with administration of the antipsychotic drug, sulpiride. The lack of interaction between these structures in this model could explain the attentional deficits in schizophrenia patients and shed light onto their inability to focus on a single task.
Gender Inequalities and Risk During the ‘Rush Hour’ of Life
Authors: Bowman Dina , Bodsworth Eve , Zinn Jens O.
Published: October 2012

Increasingly, social policies combine to intensify old risks and create new social risks with unequal consequences for men and women. These risks include those created by changing normative expectations and the resulting tensions between social policy, paid employment and family life. Policy reliance on highly aggregated standardised outcome data and generalised models of autonomous rational action result in policies that lack an understanding of the rationales that structure everyday life. Drawing on two Australian studies, we illustrate the importance of attending to the intersections and collisions of social change and normative policy frameworks from the perspective of individual ‘lived lives’.
Amplitude morphology of GPS radio occultation data for sporadic‐E layers
Authors: Yeh Wen‐Hao , Huang Cheng‐Yung , Hsiao Tung‐Yuan , Chiu Tsen‐Chieh , Lin Chien‐Hung , Liou Yuei‐An
Published: October 2012

Using the Global Positioning System radio occultation (GPSRO) technique, the observation of the global ionosphere becomes possible. The irregularity in the ionospheric sporadic‐E (Es) layer, which is probably caused by wind shear, can be investigated by analyzing the signal‐to‐noise ratio (SNR) of RO signal. In this study, the relation between the amplitude of RO signals and the electron density profiles of the ionosphere is simulated, and RO data recorded in the time period from mid‐2008 to mid‐2011 are used for the analysis. Based on the simulation results, the multiple‐layer‐type (MLT) and the single‐layer‐type (SLT)Es layers which are defined by the shape of SNR, are used to analyze the global distribution of Es layer. The seasonal MLT Es layer is compared with the seasonal wind shear, which is obtained from the Horizontal Wind Model (HWM07). Furthermore, the seasonal MLT Es layer is compared with the SLT Es layer, and the global altitude distributions of MLT and SLT Es layers are similar while the magnitude distributions are different. Unlike the MLT Es layer, the global distribution of the SLT Es layer is similar to the distribution of E region peak electron density (NmE), which is related to the solar zenith angle.
Post‐breakup tectonics in southeast Brazil from thermochronological data and combined inverse‐forward thermal history modeling
Authors: Cogné Nathan , Gallagher Kerry , Cobbold Peter R. , Riccomini Claudio , Gautheron Cecile
Published: October 2012

The continental margin of southeast Brazil is elevated. Onshore Tertiary basins and Late Cretaceous/Paleogene intrusions are good evidence for post breakup tectono‐magmatic activity. To constrain the impact of post‐rift reactivation on the geological history of the area, we carried out a new thermochronological study. Apatite fission track ages range from 60.7 ± 1.9 Ma to 129.3 ± 4.3 Ma, mean track lengths from 11.41 ± 0.23 μm to 14.31 ± 0.24 μm and a subset of the (U‐Th)/He ages range from 45.1 ± 1.5 to 122.4 ± 2.5 Ma. Results of inverse thermal history modeling generally support the conclusions from an earlier study for a Late Cretaceous phase of cooling. Around the onshore Taubaté Basin, for a limited number of samples, the first detectable period of cooling occurred during the Early Tertiary. The inferred thermal histories for many samples also imply subsequent reheating followed by Neogene cooling. Given the uncertainty of the inversion results, we did deterministic forward modeling to assess the range of possibilities of this Tertiary part of the thermal history. The evidence for reheating seems to be robust around the Taubaté Basin, but elsewhere the data cannot discriminate between this and a less complex thermal history. However, forward modeling results and geological information support the conclusion that the whole area underwent cooling during the Neogene. The synchronicity of the cooling phases with Andean tectonics and those in NE Brazil leads us to assume a plate‐wide compressional stress that reactivated inherited structures. The present‐day topographic relief of the margin reflects a contribution from post‐breakup reactivation and uplift.
High‐resolution seismic velocity structure beneath the Hokkaido corner, northern Japan: Arc‐arc collision and origins of the 1970 M 6.7 Hidaka and 1982 M 7.1 Urakawa‐oki earthquakes
Authors: Kita Saeko , Hasegawa Akira , Nakajima Junichi , Okada Tomomi , Matsuzawa Toru , Katsumata Kei
Published: October 2012

Using travel time data from both a nationwide dense seismic network and a dense temporary seismic network, we obtain a high‐resolution three‐dimensional seismic velocity structure beneath the Hokkaido corner. Considerable inhomogeneity in the seismic velocity structure is clearly imaged above the subducting Pacific slab. Our results indicate that a broad low‐velocity zone of P and S waves, with velocities consistent for crustal rocks, is observed west of the Hidaka main thrust at depths of 35–90 km. The images also indicate that several smaller‐scale high‐velocity zones are located at depths of 0–35 km, striking approximately north‐south and inclined to the east‐northeastward at 40°–60°. All of these anomalous high‐velocity zones are located at the deeper extension of Neogene thrust faults. The clearest high‐velocity zone is located beneath the Hidaka metamorphic belt and is in contact with the eastern edge of the broad low‐velocity zone. Moreover, the boundary between the clearest high‐velocity and the broad low‐velocity zones corresponds to the fault plane of the 1970 Mj (magnitude determined by the Japan Meteorological Agency) 6.7 Hidaka earthquake. The western boundary of another small high‐velocity zone, at depths of 20 to 30 km within the broad low‐velocity zone, corresponds to the fault plane of the 1982 Mj 7.1 Urakawa‐oki earthquake. These observations suggest that these two large and anomalously deep inland earthquakes occurred at sharp material boundaries under a northeast‐southwest compressional stress field caused by ongoing arc‐arc collision process.
Effects of interfacial energy on compaction creep by intergranular pressure solution: Theory versus experiments on a rock analog (NaNO3)
Authors: Visser H. J. M. , Spiers C. J. , Hangx S. J. T.
Published: October 2012

Pressure solution plays an important role in compaction and lithification of sediments and fault gouges, but the effects of interfacial energy on this process are generally neglected. Here, microphysical models for densification of solid/liquid systems by pressure solution are derived, accounting for interfacial energy besides stress‐related driving forces. They predict that densification by pressure solution creep will slow down at very fine grain sizes, where opposing interfacial energy driving forces become important compared to applied stress, and will come to a halt below a certain “yield” stress. To test the models, uniaxial compaction creep experiments were performed at ambient conditions on granular NaNO3 aggregates (d = 8–250 μm, σeff = 0.0062–4.9 MPa). Though no significant creep occurred in dry or oil‐flooded material, rapid, grain‐size sensitive creep occurred in the presence of saturated NaNO3 solution. At high effective stresses (σeff > 0.025 MPa), wet‐compacted, coarser‐grained (d > 20 μm) samples showed compaction behavior roughly consistent with diffusion‐controlled pressure solution involving negligible interfacial energy effects. Creep rates in this regime imply an effective grain boundary diffusivity product of 5.7 × 10−19 m3/s. At low effective stress (σeff < 0.025 MPa), finer‐grained samples (d < 20 μm) showed a decrease in strain rate with decreasing grain size, reflecting a growing influence of interfacial energy‐related driving forces. This demonstrates a yield stress effect, broadly consistent with the predictions of the models incorporating interfacial energy and imply that compaction by pressure solution can be strongly inhibited in very fine‐grained materials, such as nanogouge in seismogenic faults.
Oxygen decreases and variability in the eastern equatorial Pacific
Authors: Czeschel Rena , Stramma Lothar , Johnson Gregory C.
Published: October 2012

Observations indicate increasingly large and strong oxygen minimum zones (OMZs) in the tropical Pacific over recent decades. Here we report on oxygen decreases and variability within the eastern equatorial Pacific OMZ. We construct time series from historical and profiling float oxygen data and analyze data from repeat hydrographic sections at 110°W and 85°50′W. Historical data are quite sparse for constructing oxygen time series, but floats with oxygen sensors prove to be good tools to fill measurement gaps in later parts of these time series. In the region just south of the equator a time series over the last 34 years reveals that oxygen decreases from 200 to 700 m at a rate between 0.50 and 0.83 μmol kg−1 yr−1. This strong decrease seems to be related to changes in the Pacific Decadal Oscillation (PDO). Oscillations on shorter time scales (e.g., an El Niño signal in the upper 350 m) are superimposed upon this trend. In the section data, a general trend of decreasing oxygen is present below the surface layer. While velocity differences appear related to oxygen differences in the equatorial channel, there is less correlation elsewhere. Contrasting with long‐term trend computations, the trends derived from two repeat sections are obscured by the influence of seasonal and longer‐term variability. Multidecadal variability (e.g., PDO) has the strongest influence on long‐term trends, while El Niño, isopycnal heave, current variability, seasonal cycles, and temperature changes are less important.
The impact of Eastern‐Pacific versus Central‐Pacific El Niños on the North Equatorial Countercurrent in the Pacific Ocean
Authors: Hsin Yi‐Chia , Qiu Bo
Published: October 2012

Using a three‐dimensional ocean reanalysis data product, the influence of two types of the El Niños on the North Equatorial Countercurrent (NECC) across the Pacific basin is examined in this study. Eastern‐Pacific El Niños (EP‐El Niños) exert a significant impact on the interannual changes of the NECC, whereas Central‐Pacific El Niños (CP‐El Niños) have little influence. From the developing to mature phase of the EP‐El Niños that occursfrequently in the latter half of a calendar year, the NECC tends to intensify and shift southward. While the EP‐El Niño‐related position changes of the NECC is out of phase with its seasonal position changes, the EP‐El Niño‐related intensity variability of the NECC is in phase with its seasonal modulation. During both types of El Niños, the El Niño‐modulated wind stress curl forcing changes the upper ocean thickness, modifying the NECC intensity and central position. The weaker and shorter fluctuations of wind stress curl forcing during the CP‐El Niño events induce irregular and insignificant changes of the NECC.
Application of lightning to passive microwave convective and stratiform partitioning in passive microwave rainfall retrieval algorithm over land from TRMM
Authors: Wang Nai‐Yu , Gopalan Kaushik , Albrecht Rachel I.
Published: October 2012

This study analyzes relationships between lightning flash rate, radar reflectivity factor (reflectivity), and passive microwave brightness temperature (Tb) for convective and stratiform precipitation over land using multiyear data from the Tropical Rainfall Measuring Mission (TRMM) satellite. A new convective and stratiform index (CSI (an estimate of convective areal fraction)) for the TRMM Microwave Imager (TMI) is developed from the analysis. Four years of TRMM TMI, Lightning Imaging Sensor (LIS), and Precipitation Radar (PR) data (2002–2005) are colocated and remapped to 0.1 and 0.05 degree grids for analysis. The scientific objective of this study is to understand the relationship between lightning and active and passive microwave precipitation observations and explore ways of using lightning information to enhance the discrimination between convective and stratiform precipitation in TMI rain rate retrieval algorithm. PR provides the reference convective and stratiform classification and is coincident with LIS which reports lightning parameters such as the occurrence (yes or no) and flash rates. Analysis of ∼14 million coincident precipitating TRMM measurements over land (i.e., excluding oceans and coasts) reveals that 6% of rain data have lightning flash rates greater than zero. For all lightning data, 60% have 0–1 fl min−1, 28% have 1–2 fl min−1, and 12% have flash rates greater than 2 fl min−1. Overall, 86.5% (13.5%) of lightning occurred in convective (stratiform) precipitation. In other words, stratiform rainfall is predominant when LIS detects no lightning, and the convective rain probability increases with increasing lightning frequency. For example, 34% of rainfall is convective for low flash rates (0–1 fl/min), whereas the convective probability increases to 99.7% for high flash rates (>=2 fl/min). This study develops a simple method that incorporates lightning into the CSI to test if lightning can help passive microwave (PM) delineate convective and stratiform precipitation. LIS lightning occurrence and flash rates (i.e., no flash, 0–1 fl/min, 1–2 fl/min, and >2 fl/min) are used to preclassify TMI Tbs into four groups of increasing convective probability. Multivariable linear regression is then applied to each group to derive the CSI. Results reveal that lightning information primarily improves the identification of highly convective rainfall by correctly shifting microwave observations previously identified as moderate to highly convective. Alternatively, the absence of lightning also helps PM to identify likely stratiform. Overall, including lightning information results in a decrease of bias error of 6% and a small increase in RMS error of 4.5% on the entire range of rainfall rates.
Spatiotemporal variation of rainfall over the central Himalayan region revealed by TRMM Precipitation Radar
Authors: Shrestha Dibas , Singh Prasamsa , Nakamura Kenji
Published: October 2012

The rainfall‐elevation relationship in the central Himalayan region (CHR) for pre‐monsoon and monsoon seasons is analyzed utilizing the 11‐year (1998–2008) high‐spatial‐resolution TRMM PR 2A25 near‐surface rainfall data. The results indicate a strong relationship between rainfall and elevation during both seasons. The investigation reveals a relatively large amount of rainfall over higher elevations during pre‐monsoon season. Interestingly, two significant rainfall peaks appear over the southern slope of the Himalayas during summer monsoon season. The first primary peak appears along the Sub‐Himalayas (∼500–700 m above MSL), while the second appears along the Lesser Himalayas (∼2,000–2,200 m above MSL). The former rainfall peak is attributed to fewer heavy rainfall events, and the latter to frequent, weak, but persistent rainfall. It is suggested that the atmosphere is insufficiently moist to trigger convections during the pre‐monsoon season, and sufficiently moist during summer monsoon season. The convections over the Sub‐Himalayas may moisten the middle layer, and the water vapor in the atmosphere condenses because of the forced lifting along the slope, forming the second rainfall band. The total rain amount is primarily determined by the frequency of rain. The rain‐conditioned rain rate along the slope monotonically decreases with elevation. This shows that the precipitation occurs because of forced lifting. In addition, our results show that seasonal variation of rainfall is rather similar to the variation of rainfall characteristics observed during active and break periods.
Charge rearrangement by sprites over a north Texas mesoscale convective system
Authors: Hager William W. , Sonnenfeld Richard G. , Feng Wei , Kanmae Takeshi , Stenbaek‐Nielsen H. C. , McHarg Matthew G. , Haaland Ryan K. , Cummer Steven A. , Lu Gaopeng , Lapierre Jeff L.
Published: October 2012

Charge rearrangement by sprites is analyzed for a mesoscale convective system (MCS) situated in north Texas and east New Mexico on 15 July 2010. During the thunderstorm, electric field data were recorded by the Langmuir Electric Field Array (LEFA), while magnetic field data were recorded by the charge‐moment network near Duke University. A high speed (12500 fps) video system operated at Langmuir Laboratory recorded telescopic images of the sprites. Data from the National Lightning Detection Network (NLDN) show that each sprite was preceded by a series of cloud discharges and cloud‐to‐ground discharges. The triggering event preceding the sprite was typically a positive cloud‐to‐ground (+CG) stroke. For one out of the 10 sprites that were recorded, there was a positive hump in the electric field a few milliseconds after the +CG return stroke. The size and shape of the hump roughly matched the light intensity emitted from the sprite. The electric field hump is fit by a sprite current that originates in the ionosphere and propagates downward, producing the same effect as a downward moving positive current. The integral under the current hump was 23.9 C when the velocity of the current pulse was between 0.25 c and 0.55 c. The large sprite current was followed by impulsive electromagnetic radiation which has not been previously reported and could be a recoil effect similar to what is called a “K‐change” when it is observed in a lightning flash.
Regulation of mammalian cell differentiation by long non‐coding RNAs
Authors: Hu Wenqian , Alvarez‐Dominguez Juan R , Lodish Harvey F
Published: October 2012

Differentiation of specialized cell types from stem and progenitor cells is tightly regulated at several levels, both during development and during somatic tissue homeostasis. Many long non‐coding RNAs have been recognized as an additional layer of regulation in the specification of cellular identities; these non‐coding species can modulate gene‐expression programmes in various biological contexts through diverse mechanisms at the transcriptional, translational or messenger RNA stability levels. Here, we summarize findings that implicate long non‐coding RNAs in the control of mammalian cell differentiation. We focus on several representative differentiation systems and discuss how specific long non‐coding RNAs contribute to the regulation of mammalian development.
The HIV epidemic among men who have sex with men—behaviour beats science
Authors: Mor Zohar , Dan Michael
Published: October 2012

More than three decades after the emergence of HIV/AIDS, more than 30 million people worldwide still live with the disease. In the West, those most at risk are men who have sex with men owing to a combination of social factors and, ironically, improved healthcare.