bluuebunny/crossref_metadata_2025 huggingface dataset:
Interface state density of SiO2/p-type 4H-SiC (0001), (112¯), (11¯00) metal-oxide-semiconductor structures characterized by low-temperature subthreshold slopes
Authors: Kobayashi Takuma , Nakazawa Seiya , Okuda Takafumi , Suda Jun , Kimoto Tsunenobu
Published: April 2016

Interface properties of heavily Al-doped 4H-SiC (0001) (Si-face), (112¯0) (a-face), and (11¯00) (m-face) metal-oxide-semiconductor (MOS) structures were characterized from the low-temperature gate characteristics of metal-oxide-semiconductor field-effect transistors (MOSFETs). From low-temperature subthreshold slopes, interface state density (Dit) at very shallow energy levels (ET) near the conduction band edge (Ec) was evaluated. We discovered that the Dit near Ec (Ec− 0.01 eV < ET < Ec) increases in MOS structures with higher Al doping density for every crystal face (Si-, a-, and m-face). Linear correlation is observed between the channel mobility and Dit near Ec, and we concluded that the mobility drop observed in heavily doped MOSFETs is mainly caused by the increase of Dit near Ec.
Magnetodielectric and magnetoelastic coupling in Co4Nb2O9 below Néel temperature
Authors: Xie Y. M. , Lin C. S. , Zhang H. , Cheng W. D.
Published: April 2016

The dielectric constant of Co4Nb2O9 shows an obvious upturn below Néel temperature (TN), and the magnetic field enhances this anomaly. Thus the magnetodielectric effect exists in the entire temperature region below TN, not only near TN as reported previously. At the same time, the strain exhibits a drop below TN, and the magnetic field suppresses this anomaly, demonstrating magnetoelastic coupling in Co4Nb2O9. The origin of dielectric anomaly and magnetodielectric effect below TN may be related to the phonon mode shifts induced by magnetoelastic coupling.
Influence of inserted Mo layer on the thermal stability of perpendicularly magnetized Ta/Mo/Co20Fe60B20/MgO/Ta films
Authors: Li Minghua , Lu Jinhui , Yu Guoqiang , Li Xiang , Han Gang , Chen Xi , Shi Hui , Yu Guanghua , Amiri Pedram Khalili , Wang Kang L.
Published: April 2016

We studied the thermal stability of perpendicular magnetic anisotropy (PMA) in Ta/Mo/CoFeB/MgO/Ta films with and without inserted Mo layers. In the absence of a Mo layer, the films show PMA at annealing temperatures below 300 °C. On the other hand, the insertion of a Mo layer preserves PMA at annealing temperatures of up to 500 °C; however, a higher annealing temperature leads to the collapse of PMA. X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM) were used to study the microstructure of the films to understand the deterioration of PMA. The XPS results show that the segregation of Ta is partly suppressed by inserting a Mo layer. Once inserted, Mo does not remain at the interface of Ta and CoFeB but migrates to the surface of the films. The HRTEM results show that the crystallization of the MgO (001) texture is improved owing to the higher annealing temperature of the Mo inserted sample. A smooth and clear CoFeB/MgO interface is evident. The inserted Mo layer not only helps to obtain sharper and smoother interfaces but also contributes to the crystallization after the higher annealing temperature of films.
Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films
Authors: Saikia Partha , Saikia Bipul Kumar , Bhuyan Heman
Published: April 2016

We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te), electron density (ne), ion density (ni), degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.
Implementation of a driver licensing support program in three Aboriginal communities: a brief report from a pilot program
Authors: Cullen Patricia , Clapham Kathleen , Byrne Jake , Hunter Kate , Rogers Kris , Senserrick Teresa , Keay Lisa , Ivers Rebecca
Published: April 2016

Issue addressed

Aboriginal people face significant barriers to accessing the driver licensing system in New South Wales (NSW). Low rates of licence participation contribute to transport disadvantage and impede access to employment, education and essential health services. The Driving Change program has been piloted in three communities to increase licensing rates for young Aboriginal people. This brief report reviews implementation to determine whether Driving Change is being delivered as intended to the target population.

Methods

Descriptive analysis of routinely collected program data collected between April 2013 and October 2014 to monitor client demographics (n = 194) and program‐specific outcomes.

Results

The target population is being reached with the majority of clients aged 16–24 years (76%) and being unemployed (53%). Licensing outcomes are being achieved at all pilot sites (learner licence 19%; provisional or unrestricted licence 16%). There is variation in program delivery across the three pilot sites demonstrating the intended flexibility of the program.

Conclusions

Driving Change is delivering all aspects of the program as intended at the three pilot sites. The program is reaching the target population and providing a sufficiently flexible program that responds to community and client identified need.

So what?

Reviewing implementation of community pilot programs is critical to ensure that the intervention is being delivered as intended to the target population. This brief report indicates that Driving Change is assisting young Aboriginal people to access licensing services in NSW. This review of program implementation will assist the subsequent expansion of the program to a further nine communities in NSW.
The impact of alcohol management practices on sports club membership and revenue
Authors: Wolfenden L. , Kingsland M. , Rowland B. , Dodds P. , Sidey M. , Sherker S. , Wiggers J.
Published: April 2016

Issue addressed

The aim of this study was to assess the impact of an alcohol management intervention on community sporting club revenue (total annual income) and membership (number of club players, teams and spectators).

Methods

The study employed a cluster randomised controlled trial design that allocated clubs either an alcohol accreditation intervention or a control condition. Club representatives completed a scripted telephone survey at baseline and again ~3 years following. Demographic information about clubs was collected along with information about club income.

Results

Number of players and senior teams were not significantly different between treatment groups following the intervention. The intervention group, however, showed a significantly higher mean number of spectators. Estimates of annual club income between groups at follow‐up showed no significant difference in revenue.

Conclusions

This study found no evidence to suggest that efforts to reduce alcohol‐related harm in community sporting clubs will compromise club revenue and membership.

So what?

These findings suggest that implementation of an intervention to improve alcohol management of sporting clubs may not have the unintended consequence of harming club viability.
Biochemical properties of highly mineralised and infertile soil modified by acacia and spinifex plants in northwest Queensland, Australia
Authors: You Fang , Dalal Ram C. , Huang Longbin
Published: April 2016

Root zone soil properties can significantly influence the establishment of revegetated plant communities and alter their development trajectories in mined landscapes, due to closely coupled biogeochemical linkages between soil and plant systems. The present study aimed to characterise physicochemical and biochemical conditions in soil colonised by slow-growing native plant species: Acacia chisholmii (C3, native leguminous shrub) and Triodia pungens (spinifex C4 grass) in Mt Isa, North-west Queensland, Australia. This is to provide the basis for engineering growth media and root zones suitable for supporting target native plant communities to be revegetated in mined landscapes under subtropical and semiarid climatic conditions. Litter chemistry, soil physicochemical properties, and microbial community structure based on phospholipid fatty acids (PLFAs) biomarker method and activities (basal respiration, net mineralisation, dehydrogenase, invertase, urease and neutral phosphatase activities) were characterised in the surface soils beneath the keystone native plant species. Results showed that soils sampled were generally infertile with low levels of total organic carbon (TOC), available nutrients and slow cycling processes with bacteria dominant microbial communities supporting the native plant species. Surface soils underneath acacia and spinifex were modified by in situ litter return, in terms of TOC, and structure and functions of microbial communities. The levels of soil microbial biomass C and N, basal respiration rate and net mineralisation rate in the acacia soil were twice as much as those in the spinifex. Microbial communities in the acacia soil had a greater fungal:bacterial ratio than in the spinifex. On this basis, growth media and root zones for revegetating native acacia-spinifex communities at local mined landscapes may be engineered by using plant organic matter remediation to supply available nutrients and to rehabilitate suitable microbial communities for in situ litter decomposition and nutrient cycling.
Cotranslational association of mRNA encoding subunits of heteromeric ion channels
Authors: Liu Fang , Jones David K. , de Lange Willem J. , Robertson Gail A.
Published: April 2016

Significance

Many ion channels are composed of related but structurally distinct membrane protein subunits, each determining the functional properties of the channel. Although their composition is carefully regulated, the mechanisms underlying their assembly are poorly understood. We show that mRNA transcripts encoding human ether-à-go-go-related gene (hERG) 1a and 1b subunits, which assemble to form channels mediating cardiac repolarization, are physically associated and can be coimmunoprecipitated with an Ab against the nascent hERG 1a protein. Their association allows the subunits to interact during protein translation to form the heteromeric ion channel. These findings are important for understanding hERG channels, which are a target for acquired and congenital long QT syndrome, and may be generalizable to oligomeric proteins serving a wide range of biological functions.
In vitro system using human neurons demonstrates that varicella-zoster vaccine virus is impaired for reactivation, but not latency
Authors: Sadaoka Tomohiko , Depledge Daniel P. , Rajbhandari Labchan , Venkatesan Arun , Breuer Judith , Cohen Jeffrey I.
Published: April 2016

Significance

The varicella vaccine is highly effective in preventing chickenpox. Although the vaccine virus is attenuated, it is unknown whether the virus is impaired for establishment of latency, for reactivation, or both. We developed an in vitro system using human neurons derived from ES cells and showed that axonal infection of neurons results in latent infection and that virus can be reactivated using Ab to NGF. Using this system, we show that the varicella vaccine is impaired for reactivation, but not latency. Although not necessarily equivalent to varicella-zoster virus (VZV) latency and reactivation in vivo, this system may be used to study the ability of other viruses, including viral vaccines, to establish latency and reactivate.
Novel DLK-independent neuronal regeneration in
Caenorhabditis elegans
shares links with activity-dependent ectopic outgrowth
Authors: Chung Samuel H. , Awal Mehraj R. , Shay James , McLoed Melissa M. , Mazur Eric , Gabel Christopher V.
Published: April 2016

Significance

By laser surgery, genetics, and pharmacology, we demonstrate that neurons of the nematode
Caenorhabditis elegans
undergo a novel form of regeneration that is largely independent of defined regeneration pathways, including DLK, which underlies axon regeneration from
C. elegans
to mammals. Our results indicate genetic and molecular connections between DLK-independent regeneration and a previously studied activity-dependent ectopic axon outgrowth in
C. elegans
. We also note numerous similarities with lesion-conditioned regeneration, in which reduction of sensory activity triggers robust axon regeneration in the mammalian CNS. Our study unites disparate forms of neurite outgrowth to uncover the molecular mechanisms that modulate regeneration in the adult CNS and suggests that ectopic outgrowth might represent a powerful gene discovery platform for regeneration.
Syntheses and Biological Activities of Analogs of Abscisic Acid
Authors: Oritani Takayuki , Yamashita Kyohei
Published: April 2016

Selenium dioxide oxidation of methyl α-ionylideneacetate (IIb) in ethanol afforded methyl 1′-and 4′-hydroxy-α-ionylideneacetate (IIIb and IV), methyl 3′-hydroxy-β-ionylideneacetate (V) and crude dihydroxy-ionylideneacetate (VI). The latter was oxidized with active manganese dioxide to give methyl abscisate (Ib). The growth and germination-inhibitory activity of compounds related to abscisic acid on Azuki bean seedlings and some species of seeds were examined.
Physical and Chemical Properties of Crystalline Acetylesterase from Sclerotinia Fungus
Authors: Oi Susumu
Published: April 2016

The molecular weight of crystalline acetylesterase (AcE) from Sclerotinia libertiana was determined to be 78,500 by both Archibald and gel filtration methods. The sedimentation coefficient, , was determined to be 5.05 S. The amino acids and carbohydrate composition of AcE was determined as follows: Lys12 His14 Argi18 Asp76 Thr52 Ser62 Glu60 Pro48 Gly90 Ala57 Cysteine4 Val36 Met8 Ile37 Leu42 Tyr38 Phe35 Trp19 (carbohydrate as glucose)16. The amino and carboxyl terminals of AcE were found to be threonine and serine, respectively. Iso-electric focusing electrophoresis with carrier ampholite revealed that AcE has an isoelectric point at around 3.95. Optical rotatory dispersion measurements showed that [α]d, a0, b0 and λc were −22, −110, −75 and 234.5 nm, respectively, suggesting that the enzyme contains 11% of the α-helix structure.
Influence of Early and Prolonged Protein Depletion in the Diet on in vitro Protein Synthesis in Muscle and Liver of Rats
Authors: Goto Akihiko , Kametaka Masao
Published: April 2016

Male rats weighing about 200 g were killed after 1, 2, 4, 10, and 20 days on a protein-free diet, and in vitro synthesis of protein was measured by the incorporation of 14C-glycine into protein of liver slices and isolated soleus muscle. The incorporation value was corrected for the differences in specific radioactivity of intracellular free glycine, and protein and RNA contents of tissue were determined.

Muscle protein synthesis began to decrease from the 1st day of depletion, fell rapidly until the 4th day, and then was reduced gradually to about 30 % of the initial control by the 20th day. This reduction was due in a major part to a fall in the rate of protein synthesis per unit of RNA and in a minor part to a decline in RNA content. In the liver, protein synthesis increased in the early period of protein depletion, but declined with prolonged depletion, and was reduced greatly by severe depletion. These alterations were caused mainly by the changes in incorporative activity per unit of RNA.

From these results, it was suggested that different patterns of adaptive response to protein depletion occurred in both cases of early and prolonged depletion in connection with protein metabolism in rats.
Enzymatic Formation of d-Pantothemc Acid-β-Glucoside by Various β-Glucosidases
Authors: Kawai Fusako , Yamada Hideaki , Ogata Koichi
Published: April 2016

A β-gIucoside of d-pantothenic acid was formed from d-pantothenic acid and β-glucosyl donors such as cellobiose, phenyl-β-d-glucoside, salicin, and 4-methylumbelliferyl-β-d-glucoside and naphthol AS-BI-β-d-glucoside by various β-glucosidases, i.e., almond β-glucosidase, cellulase type II and III, naringinase, and hesperiginase. The compound was isolated from a reaction mixture of almond β-glucosidase by treatment with active charcoal, Amberlite CG–50, and DEAH-cellulose column chromatography, paper chromatography, and Sephadex G-IO gel filtration. Then, the compound was characterized as 4′-O-(β-d-glucopyranosyl)-d-pantothenic acid by various analytical methods including bioassay, paper chromatography, NMR and specific optical rotation. The microbiological activities of the compound were also determined.
Characterization of new early-season commercial apricot cultivars in Israel and comparison to a local cultivar
Authors: Guillén Fabian , Weksler Asya , Lurie Susan , Friedman Haya
Published: April 2016

Ripening parameters of newly released apricot cultivars (“Nitzan” and “Daniel”) are characterized and compared to an old local cultivar (“Mustakaui”), which is a white fleshed, sweeter, and smaller fruit, with a shorter shelf life. In 2 consecutive years, at harvest, we examined total soluble solids (TSS) and total acidity (TA) and, during postharvest, chlorophyll and firmness loss, and ethylene and carbon dioxide production rates. Our results show that “Mustakaui” is indeed sweeter and has a lower total acidity content than the other cultivars. However, “Mustakaui” has a similar rate of chlorophyll and firmness loss as the new cultivars. Despite similar rates of chlorophyll and firmness loss, “Mustakaui” produces the highest levels of carbon dioxide and “Daniel” produces the highest ethylene levels. “Nitzan”, on the other hand, did not produce any ethylene in 2 consecutive years, which suggests that another ripening control mechanism exists in this cultivar. Hence, the new cultivars might harbor different ripening programs in comparison to the old “Mustakaui” cultivar. Comparing the levels of volatiles in “Mustakaui” and “Nitzan” indicates that they share the capacity to produce similar volatiles, but these are produced differently in tree-ripened or postharvest-ripened fruits. Variability in volatiles might be useful for any future breeding programs for aroma.
Quality evaluation in small-scale resistance spot welding by electrode voltage recognition
Authors: Wan X. , Wang Y. , Zhao D.
Published: April 2016

This study focuses on weld quality evaluation by electrode voltage in small-scale resistance spot welding of titanium alloy. Voltage curve could be divided into four stages based on the variation characteristic. The single voltage peak was detected as combined effects of increasing bulk material resistivity and nugget size. Variations of voltage curve shape, voltage peak and failure load were more sensitive to welding current than electrode force. A generalised regression neural network was proposed to evaluate weld quality using features extracted from voltage signal. A discrete Hopfield neural network was also applied for electrode voltage recognition. The recognised voltage patterns were found effective in identifying different quality levels. A real-time and on-line quality monitoring system could be developed.
Dissimilar Al/steel friction stir spot welding: To penetrate into the lower steel sheet or not?
Authors: Fereiduni E. , Movahedi M. , Kokabi A. H.
Published: April 2016

There has always been a question about which condition results in superior mechanical properties in friction stir spot welds: (i) when the tool tip penetrates into the lower sheet or (ii) when the tool tip does not touch it. Given the question, the effects of the tool penetration depth were investigated on the microstructure and mechanical behaviour of dissimilar Al-5083/St-12 joints produced by friction stir spot welding (FSSW). Two different processes named as non- penetrating and penetrating FSSW were used. Optical and scanning electron microscopes as well as microhardness and tensile–shear tests were utilised to examine the obtained joints. The results showed that the penetrating process led to the stronger joints with lower fracture energy. The differences were studied in the light of the joining mechanisms and the formation of Al/Fe intermetallic compounds.
Fixed allocation patterns, rather than plasticity, benefit recruitment and recovery from drought in seedlings of a desert shrub
Authors: Zhang Yao , Li Yan , Xie Jiang-Bo
Published: April 2016

The response of plants to drought is controlled by the interaction between physiological regulation and morphological adjustment. Although recent studies have highlighted the long-term morphological acclimatization of plants to drought, there is still debate on how plant biomass allocation patterns respond to drought. In this study, we performed a greenhouse experiment with first-year seedlings of a desert shrub in control, drought and re-water treatments, to examine their physiological and morphological traits during drought and subsequent recovery. We found that (i) biomass was preferentially allocated to roots along a fixed allometric trajectory throughout the first year of development, irrespective of the variation in water availability; and (ii) this fixed biomass allocation pattern benefited the post-drought recovery. These results suggest that, in a stressful environment, natural selection has favoured a fixed biomass allocation pattern rather than plastic responses to environmental variation. The fixed ‘preferential allocation to root’ biomass suggests that roots may play a critical role in determining the fate of this desert shrub during prolonged drought. As the major organ for resource acquisition and storage, how the root system functions during drought requires further investigation.
Multidisciplinary perspectives on the history of human interactions with life in the ocean
Authors: MacDiarmid Alison , MacKenzie Brian , Ojaveer Henn
Published: April 2016

There is an essentially circular interaction between the human social system and the marine ecosystem. The Oceans Past V Conference “Multidisciplinary perspectives on the history of human interactions with life in the ocean” held in Tallinn, Estonia, in May 2015 was an opportunity for the presentation and discussion of papers on a diverse array of topics that examined this socio-ecological system from a historical perspective. Here we provide background to the disciplines participating in the conference and to the conference itself. We summarize the conference papers that appear in this special volume of the ICES JMS and highlight issues which arose during general discussion. We make two conclusions. First, to have greater impact and ensure more efficient use of knowledge gained from marine historical ecology (MHE) and marine environmental history (MEH) in ecosystem-based management and related policy development, practitioners need to work more routinely with population and ecological modellers and statisticians. This will allow greater processing of the available historical data to derive ecologically meaningful properties that can then be used to assess the ecological impact of long-term changes of affected species and define appropriate and realistic management targets. Second, increased multi- and trans-disciplinary effort is required to better understand the relative importance of different human demographic, technological, economic, and cultural drivers on the patterns, intensities and trajectories of human activities affecting marine ecosystems.
T-Cell Activation Independently Associates With Immune Senescence in HIV-Infected Recipients of Long-term Antiretroviral Treatment
Authors:   AGEhIV Study Group, Jiménez Viviana Cobos , Wit Ferdinand W. N. M. , Joerink Maaike , Maurer Irma , Harskamp Agnes M. , Schouten Judith , Prins Maria , van Leeuwen Ester M. M. , Booiman Thijs , Deeks Steven G. , Reiss Peter , Kootstra Neeltje A.
Published: April 2016

Background.  Aging-associated noncommunicable comorbidities are more prevalent among human immunodeficiency virus type 1 (HIV)–infected individuals than among HIV-uninfected individuals. Residual HIV-related chronic immune activation and senescence may increase the risk of developing comorbidities.

Methods.  Immune phenotyping, thymic output, and telomere length were assessed in 94 HIV-infected individuals who were aged >45 years and receiving antiretroviral therapy (ART; cases) and 95 age-matched uninfected controls.

Results.  Cases had lower CD4+ T-cell counts, higher CD8+ T-cell counts, and increased levels of immune activation (ie, increased soluble CD14 [sCD14] level and increased percentages of CD38+HLA-DR+ cells among both CD4+ and CD8+ T cells), regulatory T cells, and percentage of programmed cell death 1 (PD-1)–expressing cells among CD4+ T cells. Immune senescence levels (ie, percentages of CD27−CD28− cells or CD57+ cells) were comparable between cases and controls. Peripheral blood mononuclear cells from cases had shorter telomeres but increased single-joint T-cell receptor excision circle content and CD31+ naive CD4+ T cells. Although cytomegalovirus (CMV) antibody titers were higher in cases, CMV-specific T-cell responses were comparable between cases and controls. T-cell senescence in cases was independently associated with T-cell activation but not with CMV-specific immune responses.

Conclusions.  Despite long-term receipt of ART, HIV-infected adults had higher levels of immune activation, regulatory T cells, and PD-1–expressing CD4+ cells and shorter telomeres. The increased soluble CD14 levels and percentage of CD38+HLA-DR+ cells among CD4+ T cells correlated with shorter telomeres and increased regulatory T-cell levels. This suggests that HIV influences immune function irreversibly, with several pathways that are persistently abnormal during effective ART. Therapies aimed at improving immune health during ART are needed.
Clarifying misconceptions of extinction risk assessment with the IUCN Red List
Authors: Collen Ben , Dulvy Nicholas K. , Gaston Kevin J. , Gärdenfors Ulf , Keith David A. , Punt André E. , Regan Helen M. , Böhm Monika , Hedges Simon , Seddon Mary , Butchart Stuart H. M. , Hilton-Taylor Craig , Hoffmann Michael , Bachman Steven P. , Akçakaya H. Reşit
Published: April 2016

The identification of species at risk of extinction is a central goal of conservation. As the use of data compiled for IUCN Red List assessments expands, a number of misconceptions regarding the purpose, application and use of the IUCN Red List categories and criteria have arisen. We outline five such classes of misconception; the most consequential drive proposals for adapted versions of the criteria, rendering assessments among species incomparable. A key challenge for the future will be to recognize the point where understanding has developed so markedly that it is time for the next generation of the Red List criteria. We do not believe we are there yet but, recognizing the need for scrutiny and continued development of Red Listing, conclude by suggesting areas where additional research could be valuable in improving the understanding of extinction risk among species.
Urbanization shapes the demographic history of a native rodent (the white-footed mouse,
Peromyscus leucopus
) in New York City
Authors: Harris Stephen E. , Xue Alexander T. , Alvarado-Serrano Diego , Boehm Joel T. , Joseph Tyler , Hickerson Michael J. , Munshi-South Jason
Published: April 2016

How urbanization shapes population genomic diversity and evolution of urban wildlife is largely unexplored. We investigated the impact of urbanization on white-footed mice,
Peromyscus leucopus,
in the New York City (NYC) metropolitan area using coalescent-based simulations to infer demographic history from the site-frequency spectrum. We assigned individuals to evolutionary clusters and then inferred recent divergence times, population size changes and migration using genome-wide single nucleotide polymorphisms genotyped in 23 populations sampled along an urban-to-rural gradient. Both prehistoric climatic events and recent urbanization impacted these populations. Our modelling indicates that post-glacial sea-level rise led to isolation of mainland and Long Island populations. These models also indicate that several urban parks represent recently isolated
P. leucopus
populations, and the estimated divergence times for these populations are consistent with the history of urbanization in NYC.
Alternate non-stop migration strategies of pied flycatchers to cross the Sahara desert
Authors: Ouwehand Janne , Both Christiaan
Published: April 2016

Each year more than two billion songbirds cross the Sahara, but how they perform this formidable task is largely unknown. Using geolocation tracks from 27 pied flycatchers, a nocturnally migrating passerine, we show that most birds made diurnal flights in both autumn and spring. These diurnal flights were estimated to be part of non-stop flights of mostly 40–60 h. In spring, birds flew across the Sahara, while autumn migration probably circumpassed part of the desert, through a long oversea flight. Our data contradict claims that passerines cross the Sahara by intermittent flight and daytime resting. The frequent occurrence of long non-stop flights to cross the desert shows migrants' physiological abilities and poses the question why this would not be the general migration strategy to cross the Sahara.
A novel video-tracking system to quantify the behaviour of nocturnal mosquitoes attacking human hosts in the field
Authors: Angarita-Jaimes N. C. , Parker J. E. A. , Abe M. , Mashauri F. , Martine J. , Towers C. E. , McCall P. J. , Towers D. P.
Published: April 2016

Many vectors of malaria and other infections spend most of their adult life within human homes, the environment where they bloodfeed and rest, and where control has been most successful. Yet, knowledge of peri-domestic mosquito behaviour is limited, particularly how mosquitoes find and attack human hosts or how insecticides impact on behaviour. This is partly because technology for tracking mosquitoes in their natural habitats, traditional dwellings in disease-endemic countries, has never been available. We describe a sensing device that enables observation and recording of nocturnal mosquitoes attacking humans with or without a bed net, in the laboratory and in rural Africa. The device addresses requirements for sub-millimetre resolution over a 2.0 × 1.2 × 2.0 m volume while using minimum irradiance. Data processing strategies to extract individual mosquito trajectories and algorithms to describe behaviour during host/net interactions are introduced. Results from UK laboratory and Tanzanian field tests showed that
Culex quinquefasciatus
activity was higher and focused on the bed net roof when a human host was present, in colonized and wild populations. Both
C. quinquefasciatus
and
Anopheles gambiae
exhibited similar behavioural modes, with average flight velocities varying by less than 10%. The system offers considerable potential for investigations in vector biology and many other fields.
Estimating biologically relevant parameters under uncertainty for experimental within-host murine West Nile virus infection
Authors: Banerjee Soumya , Guedj Jeremie , Ribeiro Ruy M. , Moses Melanie , Perelson Alan S.
Published: April 2016

West Nile virus (WNV) is an emerging pathogen that has decimated bird populations and caused severe outbreaks of viral encephalitis in humans. Currently, little is known about the within-host viral kinetics of WNV during infection. We developed mathematical models to describe viral replication, spread and host immune response in wild-type and immunocompromised mice. Our approach fits a target cell-limited model to viremia data from immunocompromised knockout mice and an adaptive immune response model to data from wild-type mice. Using this approach, we first estimate parameters governing viral production and viral spread in the host using simple models without immune responses. We then use these parameters in a more complex immune response model to characterize the dynamics of the humoral immune response. Despite substantial uncertainty in input parameters, our analysis generates relatively precise estimates of important viral characteristics that are composed of nonlinear combinations of model parameters: we estimate the mean within-host basic reproductive number,R0, to be 2.3 (95% of values in the range 1.7–2.9); the mean infectious virion burst size to be 2.9 plaque-forming units (95% of values in the range 1.7–4.7); and the average number of cells infected per infectious virion to be between 0.3 and 0.99. Our analysis gives mechanistic insights into the dynamics of WNV infection and produces estimates of viral characteristics that are difficult to measure experimentally. These models are a first step towards a quantitative understanding of the timing and effectiveness of the humoral immune response in reducing host viremia and consequently the epidemic spread of WNV.
A combined within-host and between-hosts modelling framework for the evolution of resistance to antimalarial drugs
Authors: Legros Mathieu , Bonhoeffer Sebastian
Published: April 2016

The spread of drug resistance represents a significant challenge to many disease control efforts. The evolution of resistance is a complex process influenced by transmission dynamics between hosts as well as infection dynamics within these hosts. This study aims to investigate how these two processes combine to impact the evolution of resistance in malaria parasites. We introduce a stochastic modelling framework combining an epidemiological model ofPlasmodiumtransmission and an explicit within-human infection model for two competing strains. Immunity, treatment and resistance costs are included in the within-host model. We show that the spread of resistance is generally less likely in areas of intense transmission, and therefore of increased competition between strains, an effect exacerbated when costs of resistance are higher. We also illustrate how treatment influences the spread of resistance, with a trade-off between slowing resistance and curbing disease incidence. We show that treatment coverage has a stronger impact on disease prevalence, whereas treatment efficacy primarily affects resistance spread, suggesting that coverage should constitute the primary focus of control efforts. Finally, we illustrate the importance of feedbacks between modelling scales. Overall, our results underline the importance of concomitantly modelling the evolution of resistance within and between hosts.
Direct interaction of avermectin with epidermal growth factor receptor mediates the penetration resistance inDrosophilalarvae
Authors: Chen Li-Ping , Wang Pan , Sun Ying-Jian , Wu Yi-Jun
Published: April 2016

With the widespread use of avermectins (AVMs) for managing parasitic and agricultural pests, the resistance of worms and insects to AVMs has emerged as a serious threat to human health and agriculture worldwide. The reduced penetration of AVMs is one of the main reasons for the development of the resistance to the chemicals. However, the detailed molecular mechanisms remain elusive. Here, we use the larvae ofDrosophila melanogasteras the model organism to explore the molecular mechanisms underlying the development of penetration resistance to AVMs. We clearly show that the chitin layer is thickened and the efflux transporter P-glycoprotein (P-gp) is overexpressed in the AVM-resistant larvae epidermis. We reveal that the activation of the transcription factor Relish by the over-activated epidermal growth factor receptor (EGFR)/AKT/ERK pathway induces the overexpression of the chitin synthasesDmeCHS1/2and P-gp in the resistant larvae. Interestingly, we discover for the first time, to the best of our knowledge, that AVM directly interacts with EGFR and leads to the activation of the EGFR/AKT/ERK pathway, which activates the transcription factor Relish and induces the overexpression ofDmeCHS1/2and P-gp. These findings provide new insights into the molecular mechanisms underlying the development of penetration resistance to drugs.
A closed conformation of the
Caenorhabditis elegans
separase–securin complex
Authors: Bachmann Gudrun , Richards Mark W. , Winter Anja , Beuron Fabienne , Morris Edward , Bayliss Richard
Published: April 2016

The protease separase plays a key role in sister chromatid disjunction and centriole disengagement. To maintain genomic stability, separase activity is strictly regulated by binding of an inhibitory protein, securin. Despite its central role in cell division, the separase and securin complex is poorly understood at the structural level. This is partly owing to the difficulty of generating a sufficient quantity of homogeneous, stable protein. Here, we report the production of
Caenorhabditis elegans
separase–securin complex, and its characterization using biochemical methods and by negative staining electron microscopy. Single particle analysis generated a density map at a resolution of 21–24 Å that reveals a close, globular structure of complex connectivity harbouring two lobes. One lobe matches closely a homology model of the N-terminal HEAT repeat domain of separase, whereas the second lobe readily accommodates homology models of the separase C-terminal death and caspase-like domains. The globular structure of the
C. elegans
separase–securin complex contrasts with the more elongated structure previously described for the
Homo sapiens
complex, which could represent a different functional state of the complex, suggesting a mechanism for the regulation of separase activity through conformational change.
Assessing recognition memory using confidence ratings and response times
Authors: Weidemann Christoph T. , Kahana Michael J.
Published: April 2016

Classification of stimuli into categories (such as ‘old’ and ‘new’ in tests of recognition memory or ‘present’ versus ‘absent’ in signal detection tasks) requires the mapping of internal signals to discrete responses. Introspective judgements about a given choice response are regularly employed in research, legal and clinical settings in an effort to measure the signal that is thought to be the basis of the classification decision. Correlations between introspective judgements and task performance suggest that such ratings often do convey information about internal states that are relevant for a given task, but well-known limitations of introspection call the fidelity of this information into question. We investigated to what extent response times can reveal information usually assessed with explicit confidence ratings. We quantitatively compared response times to confidence ratings in their ability to qualify recognition memory decisions and found convergent results suggesting that much of the information from confidence ratings can be obtained from response times.
Dynamic calibration of agent-based models using data assimilation
Authors: Ward Jonathan A. , Evans Andrew J. , Malleson Nicolas S.
Published: April 2016

A widespread approach to investigating the dynamical behaviour of complex social systems is via agent-based models (ABMs). In this paper, we describe how such models can be dynamically calibrated using the ensemble Kalman filter (EnKF), a standard method of data assimilation. Our goal is twofold. First, we want to present the EnKF in a simple setting for the benefit of ABM practitioners who are unfamiliar with it. Second, we want to illustrate to data assimilation experts the value of using such methods in the context of ABMs of complex social systems and the new challenges these types of model present. We work towards these goals within the context of a simple question of practical value: how many people are there in Leeds (or any other major city) right now? We build a hierarchy of exemplar models that we use to demonstrate how to apply the EnKF and calibrate these using open data of footfall counts in Leeds.
Medical subject heading (MeSH) annotations illuminate maize genetics and evolution
Authors: Beissinger Timothy M. , Morota Gota
Published: April 2016

High-density marker panels and/or whole-genome sequencing,coupled with advanced phenotyping pipelines and sophisticated statistical methods, have dramatically increased our ability to generate lists of candidate genes or regions that are putatively associated with phenotypes or processes of interest. However, the speed with which we can validate genes, or even make reasonable biological interpretations about the principles underlying them, has not kept pace. A promising approach that runs parallel to explicitly validating individual genes is analyzing a set of genes together and assessing the biological similarities among them. This is often achieved via gene ontology (GO) analysis, a powerful tool that involves evaluating publicly available gene annotations. However, additional tools such as Medical Subject Headings (MeSH terms) can also be used to evaluate sets of genes to make biological interpretations. In this manuscript, wedescribe utilizing MeSH terms to make biological interpretations in maize. MeSH terms are assigned to PubMed-indexed manuscripts by the National Library of Medicine, and can be directly mapped to genes to develop gene annotations. Once mapped, these terms can be evaluated for enrichment in sets of genes or similarity between gene sets to provide biological insights. Here, we implement MeSH analyses in five maize datasets to demonstrate how MeSH can be leveraged by the maize and broader crop-genomics community.
Analysis of the halo background in femtosecond slicing experiments
Authors: Schick Daniel , Le Guyader Loïc , Pontius Niko , Radu Ilie , Kachel Torsten , Mitzner Rolf , Zeschke Thomas , Schüßler-Langeheine Christian , Föhlisch Alexander , Holldack Karsten
Published: April 2016

The slicing facility FemtoSpeX at BESSY II offers unique opportunities to study photo-induced dynamics on femtosecond time scales by means of X-ray magnetic circular dichroism, resonant and non-resonant X-ray diffraction, and X-ray absorption spectroscopy experiments in the soft X-ray regime. Besides femtosecond X-ray pulses, slicing sources inherently also produce a so-called `halo' background with a different time structure, polarization and pointing. Here a detailed experimental characterization of the halo radiation is presented, and a method is demonstrated for its correct and unambiguous removal from femtosecond time-resolved data using a special laser triggering scheme as well as analytical models. Examples are given for time-resolved measurements with corresponding halo correction, and errors of the relevant physical quantities caused by either neglecting or by applying a simplified model to describe this background are estimated.
Transferred multipolar atom model for 10β,17β-dihydroxy-17α-methylestr-4-en-3-one dihydrate obtained from the biotransformation of methyloestrenolone
Authors: Faroque Muhammad Umer , Yousuf Sammer , Zafar Salman , Choudhary M. Iqbal , Ahmed Maqsood
Published: April 2016

Biotransformation is the structural modification of compounds using enzymes as the catalysts and it plays a key role in the synthesis of pharmaceutically important compounds. 10β,17β-Dihydroxy-17α-methylestr-4-en-3-one dihydrate, C19H28O3·2H2O, was obtained from the fungal biotransformation of methyloestrenolone. The structure was refined using the classical independent atom model (IAM) and a transferred multipolar atom model using the ELMAM2 database. The results from the two refinements have been compared. The ELMAM2 refinement has been found to be superior in terms of the refinement statistics. It has been shown that certain electron-density-derived properties can be calculated on the basis of the transferred parameters for crystals which diffract to ordinary resolution.
The family variable in the French and Italian wine sector
Authors: Bresciani Stefano , Giacosa Elisa , Broccardo Laura , Culasso Francesca
Published: April 2016

Purpose

– The purpose of this paper is to highlight the differences in terms of economic and financial performance, between family firms (FFs) and non-family firms (NFFs) in the wine sector in Italy and France, where this sector is one of the most representative national economic activities.

Design/methodology/approach

– This study is based on a sample of Italian and France companies operating in the wine sector. The sample, including medium and large firms, includes 288 FFs and 302 NFFs, for a total of 590 firms. Amadeus database represents the data source. According to Astrachan and Kolenko (1994), a firm is classified as a FF if family had to own over 50 per cent of the business in a private company or more than 10 per cent of a public company.

Findings

– This study confirms that the family variable is relevant to achieve good economic and financial performance, and endow firms with different features. In terms of economic performance, FFs both in Italy and France outperform in. terms of return on equity and return on assets, though only Italian NFFs outperform in earnings before interest and taxes. In terms of financial performance, both in Italy and France NFFs outperform FFs in current ratio and liquidity ratio, while FFs outperform in solvency ratio.

Research limitations/implications

– Limitations of the study concern the method adopted, as it could be integrated with some econometrical models. The implications of the paper are relevant for families and regulatory bodies because it helps them to better understand the effects of governance on economic and financial performance. Moreover, the findings of the study can influence the decision-making process of investors in order to identify the long-term outperformers listed on a stock exchange.

Originality/value

– This study contributes to the literature on family businesses phenomenon on wine sector, which represents one of the most representative of the economy of several countries and in which family businesses are widespread.