bluuebunny/crossref_metadata_2025 huggingface dataset:
Adiabatic quantum-flux-parametron cell library adopting minimalist design
Authors: Takeuchi Naoki , Yamanashi Yuki , Yoshikawa Nobuyuki
Published: May 2015

We herein build an adiabatic quantum-flux-parametron (AQFP) cell library adopting minimalist design and a symmetric layout. In the proposed minimalist design, every logic cell is designed by arraying four types of building block cells: buffer, NOT, constant, and branch cells. Therefore, minimalist design enables us to effectively build and customize an AQFP cell library. The symmetric layout reduces unwanted parasitic magnetic coupling and ensures a large mutual inductance in an output transformer, which enables very long wiring between logic cells. We design and fabricate several logic circuits using the minimal AQFP cell library so as to test logic cells in the library. Moreover, we experimentally investigate the maximum wiring length between logic cells. Finally, we present an experimental demonstration of an 8-bit carry look-ahead adder designed using the minimal AQFP cell library and demonstrate that the proposed cell library is sufficiently robust to realize large-scale digital circuits.
Individual identification of free hole and electron dynamics in CuIn1−xGaxSe2 thin films by simultaneous monitoring of two optical transitions
Authors: Okano Makoto , Hagiya Hideki , Sakurai Takeaki , Akimoto Katsuhiro , Shibata Hajime , Niki Shigeru , Kanemitsu Yoshihiko
Published: May 2015

The photocarrier dynamics of CuIn1−xGaxSe2 (CIGS) thin films were studied using white-light transient absorption (TA) measurements, as an understanding of this behavior is essential for improving the performance of solar cells composed of CIGS thin films. A characteristic double-peak structure due to the splitting of the valance bands in the CIGS was observed in the TA spectra under near-band-gap resonant excitation. From a comparison of the TA decay dynamics monitored at these two peaks, it was found that the slow-decay components of the electron and hole relaxation are on the nanosecond timescale. This finding is clear evidence of the long lifetimes of free photocarriers in polycrystalline CIGS thin films.
Softening of infrared-active mode of perovskite BaZrO3 proved by terahertz time-domain spectroscopy
Authors: Helal M. A. , Mori T. , Kojima S.
Published: May 2015

The low-frequency infrared-active optical modes were studied in a barium zirconate, BaZrO3, single crystal with the perovskite structure using terahertz (THz) time-domain spectroscopy (TDS). The real and imaginary parts of the dielectric constants were accurately determined in the frequency range between 0.2 and 2.7 THz. Upon cooling from room temperature to 8 K, the lowest-frequency TO1 mode at 2.32 THz showed a pronounced softening to 1.94 THz. The real part of the dielectric constant at 0.5 THz determined by THz-TDS obeys Barrett's relation, and the existence of a plateau confirms that the quantum effects lead to saturation of the soft mode frequencies of the TO1 and TO2 modes below ≈20 K. This is reminiscent of incipient ferroelectrics with the perovskite structure such as CaTiO3.
Plasmon enhanced fluorescence studies from aligned gold nanorod arrays modified with SiO2 spacer layers
Authors: Damm Signe , Fedele Stefano , Murphy Antony , Holsgrove Kristina , Arredondo Miryam , Pollard Robert , Barry James N. , Dowling Denis P. , Rice James H.
Published: May 2015

Here, we demonstrate that quasi self-standing Au nanorod arrays prepared with plasma polymerisation deposited SiO2 dielectric spacers support surface enhanced fluorescence (SEF) while maintaining high signal reproducibility. We show that it is possible to find a balance between enhanced radiative and non-radiative decay rates at which the fluorescent intensity is maximized. The SEF signal optimised with a 30 nm spacer layer thickness showed a 3.5-fold enhancement with a signal variance of <15% thereby keeping the integrity of the nanorod array. We also demonstrate the decreased importance of obtaining resonance conditions when localized surface plasmon resonance is positioned within the spectral region of Au interband transitions. Procedures for further increasing the SEF enhancement factor are also discussed.
On-chip generation of Einstein-Podolsky-Rosen states with arbitrary symmetry
Authors: Gräfe Markus , Heilmann René , Nolte Stefan , Szameit Alexander
Published: May 2015

We experimentally demonstrate a method for integrated-optical generation of two-photon Einstein-Podolsky-Rosen states featuring arbitrary symmetries. In our setting, we employ detuned directional couplers to impose a freely tailorable phase between the two modes of the state. Our results allow to mimic the quantum random walk statistics of bosons, fermions, and anyons, particles with fractional exchange statistics.
A theoretical investigation of Ferromagnetic Resonance Linewidth and damping constants in coupled trilayer and spin valve systems
Authors: Layadi A.
Published: May 2015

The ferromagnetic resonance intrinsic field linewidth ΔH is investigated for a multilayer system such as a coupled trilayer and a spin valve structure. The magnetic coupling between two ferromagnetic layers separated by a nonmagnetic interlayer will be described by the bilinear J1 and biquadratic J2 coupling parameters. The interaction at the interface of the first ferromagnetic layer with the antiferromagnetic one is account for by the exchange anisotropy field, HE. A general formula is derived for the intrinsic linewidth ΔH. The explicit dependence of ΔH with HE, J1 and J2 will be highlighted. Analytical expressions for each mode field linewidth are found in special cases. Equivalent damping constants will be discussed.
Islands of globalisation: Offshore Services and the Changing Spatial Divisions of Labour
Authors: Kleibert Jana Maria
Published: May 2015

The changing international division of labour presents opportunities for developing countries to attract foreign investments and generate employment in the offshore service sector. This paper focuses on developments in the Philippines, which has become a large exporter of business process outsourcing services over the past decade. The sector employs close to 800 000 highly educated young workers, the majority of whom work night shifts in call centres. Where do offshore service firms invest in the Philippines, which spatial transformations occur as a result, and why? This paper maps the location of offshore service investments on a national and regional level and traces the genesis of service-based special economic zones (SEZs), which combine functions of service delivery for global markets with increasingly globalised consumption patterns. These service-based SEZs arise due to location choice factors of foreign investors in services offshoring, who require skilled labour and prefer modern and secure environments, modelled according to their home country. Changing government policies on spatial zoning facilitated the rise of these SEZs in central business districts in Metro Manila and existing powerful real estate developers not only enabled this development, but are also the primary local beneficiaries of this feature of contemporary globalisation.
Who Needs Good Neighbors?
Authors: Howley Peter , Neill Stephen O , Atkinson Rowland
Published: May 2015

Due to the increasing spatial dispersion of social networks, the association between neighbor relationships and quality of life has become more uncertain. Our analysis used instrumental variable modelling to reduce bias associated with residual confounding and reverse causation, in order to provide a more reliable examination of the effect of interaction with neighbors on subjective well-being than previous work. While the frames of reference for individuals' socialising may have shifted outside the neighborhood, our analysis provides robust evidence that interaction with neighbors still matters a great deal for subjective well-being. A further important question to ask is if neighboring does affect well-being, then are there certain groups in society for whom contact with neighbors matters more? Our analysis suggests that there are, namely for those in a relationship, unemployed or retired. This means that while fostering contact with neighbors has the potential to significantly improve individual well-being, such policy efforts are likely to matter a good deal more in neighborhoods with relatively large numbers of geographically constrained social groups, such as the elderly and the unemployed.
Contradictory Connectivity: Spatial Imaginaries and Technomediated Positionalities in Kenya's Outsourcing Sector
Authors: Graham Mark
Published: May 2015

East Africa has traditionally been characterized by stark barriers to nonproximate communication and flows of information. It was the world's last major region without fibre-optic broadband Internet access, and until the summer of 2009 had been forced to rely on slow and costly satellite connectivity. This all changed when the first of four fibre-optic cables was connected in Kenya: bringing with it the promise of fast and affordable Internet access for the masses, and the ability of the country to move towards a knowledge-based economy. Within the context of this moment of change, this paper explores the ways that managers of outsourcing firms envisage ‘connectivity.’ Over the course of forty-one interviews, contradictory spatial imaginaries were discovered. When describing their perceptions of the country's new technomediated positionalities, many interviewees repeated visions that allowed geographic frictions to evaporate. But when managers were asked about their actual mediated positionalities, they presented a very different world: one of barriers, frictions, and the very real role that distance continues to play in the world's economic peripheries. The goal of this paper is to interrogate why we see such stark disconnects between perceptions and practices of connectivity. The contradictions could be seen as an exposition of a scalar schism between internationally operating regimes of truth (ie, powerful discourses that have their origin nonlocally) and local experiences and practices in Kenya. Alternatively, we can think about the contradictory accounts of connectivity as emergent from strategic spatial essentialisms that are practised to achieve particular goals. By focusing on the contradictions embedded into the ways in which people speak about connectivity in the Kenyan outsourcing sector, we can learn much about how arguments about the entanglement of connectivity, growth, and development are operationalized. ‘Connectivity’ is offered as a necessary, and sometimes even sufficient, condition from which growth and economic development can be brought into being: a set of spatial imaginaries that conveniently support a national development strategy of remaking Kenya in the contemporary knowledge economy.
Phosphorus fractions in soils of the mangrove, restinga and Atlantic forest ecosystems from Cardoso Island, Brazil
Authors: Pupin Breno , Nahas Ely
Published: May 2015

The availability of phosphorus (P) for the growth of plants often depends on the solubilisation of inorganic phosphates (P fractions) in the soil. The aim of this study was to investigate soil P fractions in terms of availability and soil characteristics of mangrove soil compared with the Atlantic forest and restinga soils that occur at Cardoso Island, Brazil. Soil samples were collected during summer at depths of 0–2, 2–5 and 5–10 cm. Except for Ca-P, the quantity of P fractions in the soils decreased in the order: Atlantic forest > mangrove > restinga. Principal components analysis showed that treatments were clustered into two groups based on ecosystem proprieties; P in mangrove soil was associated with pH, moisture and salinity, and P in Atlantic forest soil with soil organic matter (SOM). The P in restinga soil was not associated with any variable. Among fractions, iron (Fe)-P was dominant, followed by calcium (Ca)-P and aluminium (Al)-P. The most recalcitrant P fractions, reductant Fe-P, occluded (o) Fe-P and oAl-P were detected in minor amounts. Soluble (sol)-P was detected only in the Atlantic forest soil. Soil P fractions varied little with depth in the mangrove and restinga soils. The P fractions from Atlantic forest soil were found at depths of 0–2 cm (Fe-P, Ca-P) and 2–5 cm (sol-P, Al-P, Fe-P, oAl-P and oFe-P). Positive correlation was obtained for all P fractions with moisture (except sol-P and Fe-P) and SOM (except Ca-P) contents and negative correlation with soil pH (except Ca-P) and salinity (except Fe-P and Al-P). Quantities and qualities of the P fractions varied among the studied ecosystems, influenced by the parent material and physico-chemical characteristics of the soil and vegetation.
Activity-dependent, homeostatic regulation of neurotransmitter release from auditory nerve fibers
Authors: Ngodup Tenzin , Goetz Jack A. , McGuire Brian C. , Sun Wei , Lauer Amanda M. , Xu-Friedman Matthew A.
Published: May 2015

Significance

Synapses with high probability of neurotransmitter release (
P
r
) depress during prolonged activity, which reduces the faithful transfer of information. Auditory nerve synapses onto bushy cells show particularly strong depression at physiologically relevant rates of activity, which raises the question of how bushy cells transmit information when sound levels are high for a prolonged period. After rearing mice in constant, nondamaging noise, auditory nerve synapses changed from high to low
P
r
, with a corresponding increase in the number of release sites, which increased spike fidelity during high activity. Neither quantal size nor average excitatory postsynaptic current changed. After returning to control conditions,
P
r
recovered to high. These changes seem to reflect a homeostatic response to enhance fidelity.
The massive mitochondrial genome of the angiosperm
Silene noctiflora
is evolving by gain or loss of entire chromosomes
Authors: Wu Zhiqiang , Cuthbert Jocelyn M. , Taylor Douglas R. , Sloan Daniel B.
Published: May 2015

Across eukaryotes, mitochondria exhibit staggering diversity in genomic architecture, including the repeated evolution of multichromosomal structures. Unlike in the nucleus, where mitosis and meiosis ensure faithful transmission of chromosomes, the mechanisms of inheritance in fragmented mitochondrial genomes remain mysterious. Multichromosomal mitochondrial genomes have recently been found in multiple species of flowering plants, including
Silene noctiflora
, which harbors an unusually large and complex mitochondrial genome with more than 50 circular-mapping chromosomes totaling ∼7 Mb in size. To determine the extent to which such genomes are stably maintained, we analyzed intraspecific variation in the mitochondrial genome of
S. noctiflora
. Complete genomes from two populations revealed a high degree of similarity in the sequence, structure, and relative abundance of mitochondrial chromosomes. For example, there are no inversions between the genomes, and there are only nine SNPs in 25 kb of protein-coding sequence. Remarkably, however, these genomes differ in the presence or absence of 19 entire chromosomes, all of which lack any identifiable genes or contain only duplicate gene copies. Thus, these mitochondrial genomes retain a full gene complement but carry a highly variable set of chromosomes that are filled with presumably dispensable sequence. In
S. noctiflora
, conventional mechanisms of mitochondrial sequence divergence are being outstripped by an apparently nonadaptive process of whole-chromosome gain/loss, highlighting the inherent challenge in maintaining a fragmented genome. We discuss the implications of these findings in relation to the question of why mitochondria, more so than plastids and bacterial endosymbionts, are prone to the repeated evolution of multichromosomal genomes.
Destructin-1 is a collagen-degrading endopeptidase secreted by
Pseudogymnoascus destructans
, the causative agent of white-nose syndrome
Authors: O’Donoghue Anthony J. , Knudsen Giselle M. , Beekman Chapman , Perry Jenna A. , Johnson Alexander D. , DeRisi Joseph L. , Craik Charles S. , Bennett Richard J.
Published: May 2015

Significance

This work identifies molecular factors produced by the fungus
Pseudogymnoascus destructans
, the causative agent of white-nose syndrome in bats. Our study reveals the repertoire of redox enzymes and hydrolytic enzymes secreted by
P. destructans
. We establish that a secreted serine peptidase, Destructin-1, is a major component of the
P. destructans
secretome. This peptidase was purified and shown to degrade collagen, the major structural protein in mammalian connective tissue. Furthermore, chemical inhibition of Destructin-1 blocked collagen degradation in conditioned media from
P. destructans
. We therefore propose that serine endopeptidases aid in invasive growth and tissue destruction by the fungus, and represent potential targets for therapeutic intervention in white-nose syndrome.
Development of LNA oligonucleotide–PCR clamping technique in investigating the community structures of plant-associated bacteria
Authors: Ikenaga Makoto , Tabuchi Masakazu , Oyama Takuya , Akagi Isao , Sakai Masao
Published: May 2015

Simultaneous extraction of plant organelle (mitochondria and plastid) genes during the DNA extraction step is major limitation in investigating the community structures of plant-associated bacteria. Although locked nucleic acid (LNA) oligonucleotides was designed to selectively amplify the bacterial small subunit rRNA genes by applying the PCR clamping technique, those for plastids were applicable only for particular plants, while those for mitochondria were available throughout most plants. To widen the applicable range, new LNA oligonucleotides specific for plastids were designed, and the efficacy was investigated. PCR without LNA oligonucleotides predominantly amplified the organelle genes, while bacterial genes were predominantly observed in having applied the LNA oligonucleotides. Denaturing gradient gel electrophoresis (DGGE) analysis displayed additional bacterial DGGE bands, the amplicons of which were prepared using the LNA oligonucleotides. Thus, new designed LNA oligonucleotides specific for plastids were effective and have widened the scope in investigating the community structures of plant-associated bacteria.
A quantitative imaging-based screen reveals the exocyst as a network hub connecting endocytosis and exocytosis
Authors: Jose Mini , Tollis Sylvain , Nair Deepak , Mitteau Romain , Velours Christophe , Massoni-Laporte Aurelie , Royou Anne , Sibarita Jean-Baptiste , McCusker Derek
Published: May 2015

The coupling of endocytosis and exocytosis underlies fundamental biological processes ranging from fertilization to neuronal activity and cellular polarity. However, the mechanisms governing the spatial organization of endocytosis and exocytosis require clarification. Using a quantitative imaging-based screen in budding yeast, we identified 89 mutants displaying defects in the localization of either one or both pathways. High-resolution single-vesicle tracking revealed that the endocytic and exocytic mutants she4∆ and bud6∆ alter post-Golgi vesicle dynamics in opposite ways. The endocytic and exocytic pathways display strong interdependence during polarity establishment while being more independent during polarity maintenance. Systems analysis identified the exocyst complex as a key network hub, rich in genetic interactions with endocytic and exocytic components. Exocyst mutants displayed altered endocytic and post-Golgi vesicle dynamics and interspersed endocytic and exocytic domains compared with control cells. These data are consistent with an important role for the exocyst in coordinating endocytosis and exocytosis.
Aortic Pulse Wave Velocity in Healthy Children and Adolescents: Reference Values for the Vicorder Device and Modifying Factors
Authors: Thurn Daniela , Doyon Anke , Sözeri Betul , Bayazit Aysun K. , Canpolat Nur , Duzova Ali , Querfeld Uwe , Schmidt Bernhard M.W. , Schaefer Franz , Wühl Elke , Melk Anette ,   for the 4C Study Consortium
Published: May 2015

BACKGROUND

Aortic pulse wave velocity (PWV), an indicator of arterial stiffness, independently predicts cardiovascular mortality risk in adults. Arterial stiffening advances with age and seems accelerated in children with certain disease conditions such as chronic kidney disease or diabetes. The Vicorder, an oscillometric device to measure PWV, has been validated in children, but reference values in a large pediatric cohort, association to carotid stiffness and influence of individual and family risk factors have not been determined.

METHODS

Pulse waves were captured in 1,003 healthy children (aged 6–18 years) in 6 centers and gender-specific reference data normalized to age/height were constructed. In 589 children carotid distensibility and intima media thickness were measured. Gestational and family history was reported.

RESULTS

PWV correlated with age (r = 0.57, P < 0.0001) with significant gender-related differences starting at age 9. Further significant correlations were seen for height, weight, body mass index, blood pressure, pulse pressure, and heart rate. Independent predictors for PWV in a multivariate regression analysis were gender, age, height, weight, mean arterial pressure, and heart rate. Risk factors for higher PWV included small for gestational age at birth, secondhand smoking, parental hypertension, and obesity. PWV showed weak correlations with 2 of the carotid distensibility measures, but not with intima media thickness.

CONCLUSION

This study defines reference values for PWV captured by the Vicorder device in children and adolescents and reveals associations with potential cardiovascular risk factors in a healthy population. Gender-specific percentiles for age/height will allow for the assessment of pediatric cohorts using this oscillometric method.
Safety and Immunogenicity of Modified Vaccinia Ankara-Bavarian Nordic Smallpox Vaccine in Vaccinia-Naive and Experienced Human Immunodeficiency Virus-Infected Individuals: An Open-Label, Controlled Clinical Phase II Trial
Authors: Overton Edgar Turner , Stapleton Jack , Frank Ian , Hassler Shawn , Goepfert Paul A , Barker David , Wagner Eva , von Krempelhuber Alfred , Virgin Garth , Weigl Josef , Meyer Thomas Peter , Müller Jutta , Bädeker Nicole , Grünert Robert , Young Philip , Rösch Siegfried , Maclennan Jane , Arndtz-Wiedemann Nathaly , Chaplin Paul
Published: May 2015

Background

First- and second-generation smallpox vaccines are contraindicated in individuals infected with human immunodeficiency virus (HIV). A new smallpox vaccine is needed to protect this population in the context of biodefense preparedness. The focus of this study was to compare the safety and immunogenicity of a replication-deficient, highly attenuated smallpox vaccine modified vaccinia Ankara (MVA) in HIV-infected and healthy subjects.

Methods

An open-label, controlled Phase II trial was conducted at 36 centers in the United States and Puerto Rico for HIV-infected and healthy subjects. Subjects received 2 doses of MVA administered 4 weeks apart. Safety was evaluated by assessment of adverse events, focused physical exams, electrocardiogram recordings, and safety laboratories. Immune responses were assessed using enzyme-linked immunosorbent assay (ELISA) and a plaque reduction neutralization test (PRNT).

Results

Five hundred seventy-nine subjects were vaccinated at least once and had data available for analysis. Rates of ELISA seropositivity were comparably high in vaccinia-naive healthy and HIV-infected subjects, whereas PRNT seropositivity rates were higher in healthy compared with HIV-infected subjects. Modified vaccinia Ankara was safe and well tolerated with no adverse impact on viral load or CD4 counts. There were no cases of myo-/pericarditis reported.

Conclusions

Modified vaccinia Ankara was safe and immunogenic in subjects infected with HIV and represents a promising smallpox vaccine candidate for use in immunocompromised populations.
Physoderma Brown Spot and Stalk Rot of Corn Caused by Physoderma maydis in Iowa
Authors: Robertson Alison E. , Jesse Laura , Munkvold Gary , Rojas Erika Salaau , Mueller Daren S.
Published: May 2015

Physoderma brown spot (PBS) and stalk rot (PSR) of corn is caused by Physoderma maydis. The prevalence of PBS in the U.S. Corn Belt has increased within the past decade. In Iowa, in 2013 and 2014, PSR with associated stalk breakage was reported from numerous fields in western and northern Iowa. In some fields, up to 80% of plants in a field were affected. The reasons for the outbreak of PSR are unknown, although abundant rain during early growth of the corn likely played a role.

Accepted for publication 2 April 2015. Published 4 May 2015.
School Attendance in Children With Functional Abdominal Pain and Inflammatory Bowel Diseases
Authors: Assa Amit , Ish‐Tov Alona , Rinawi Firas , Shamir Raanan
Published: May 2015

Objective:

Inflammatory bowel disease (IBD) and functional abdominal pain (FAP) are associated with debilitating symptoms and frequent medical visits that may disrupt school functioning. The aim of this study was to assess school‐related quality of life and school absenteeism in children with IBD, compared with FAP and healthy controls.

Methods:

School absenteeism and participation in school and after‐school activities data were obtained for 43 children with Crohn disease (CD), 31 children with ulcerative colitis (UC), 42 children with FAP, and 30 age‐matched healthy controls for the 2013–2014 school year. We used a semistructured questionnaire for both children and parents. For diminishing recall bias, absenteeism data were cross‐matched with the patient's school annual report cards.

Results:

Children with FAP, CD, and UC missed significantly more school days than age‐matched healthy controls (17.6 [8.75–30], 24 [14–30], and 21 [12–25] vs 5.1 [3.75–6.25], respectively, P < 0.001). Compared with children with FAP, absenteeism because of medical appointments and hospitalization was significantly greater in children with CD and UC (8.8 [4–14] and 7.1 [3–10] vs 4.4 [2–6.25], P = 0.001). Participation of children with FAP and IBD in various school and after‐school activities was significantly reduced compared with healthy controls. There was no difference in school attendance and functioning between children with IBD and FAP.

Conclusions:

FAP has a significant impact on school attendance and functioning similar to IBD. These findings show that significant psychosocial and academic difficulties are faced not only by children with chronic diseases like IBD but also by children with FAP.
Functional coupling constrains craniofacial diversification in Lake Tanganyika cichlids
Authors: Tsuboi Masahito , Gonzalez-Voyer Alejandro , Kolm Niclas
Published: May 2015

Functional coupling, where a single morphological trait performs multiple functions, is a universal feature of organismal design. Theory suggests that functional coupling may constrain the rate of phenotypic evolution, yet empirical tests of this hypothesis are rare. In fish, the evolutionary transition from guarding the eggs on a sandy/rocky substrate (i.e. substrate guarding) to mouthbrooding introduces a novel function to the craniofacial system and offers an ideal opportunity to test the functional coupling hypothesis. Using a combination of geometric morphometrics and a recently developed phylogenetic comparative method, we found that head morphology evolution was 43% faster in substrate guarding species than in mouthbrooding species. Furthermore, for species in which females were solely responsible for mouthbrooding the males had a higher rate of head morphology evolution than in those with bi-parental mouthbrooding. Our results support the hypothesis that adaptations resulting in functional coupling constrain phenotypic evolution.
Double trouble: combined action of meiotic drive and
Wolbachia
feminization in
Eurema
butterflies
Authors: Kern Peter , Cook James M. , Kageyama Daisuke , Riegler Markus
Published: May 2015

Arthropod sex ratios can be manipulated by a diverse range of selfish genetic elements, including maternally inherited
Wolbachia
bacteria. Feminization by
Wolbachia
is rare but has been described for
Eurema mandarina
butterflies
.
In this species, some phenotypic and functional females, thought to be ZZ genetic males, are infected with a feminizing
Wolbachia
strain,
w
Fem. Meanwhile, heterogametic WZ females are not infected with
w
Fem. Here, we establish a quantitative PCR assay allowing reliable sexing in three
Eurema
species. Against expectation, all
E. mandarina
females, including
w
Fem females, had only one Z chromosome that was paternally inherited. Observation of somatic interphase nuclei confirmed that W chromatin was absent in
w
Fem females, but present in females without
w
Fem. We conclude that the sex bias in
w
Fem lines is due to meiotic drive (MD) that excludes the maternal Z and thus prevents formation of ZZ males. Furthermore,
w
Fem lines may have lost the W chromosome or harbour a dysfunctional version, yet rely on
w
Fem for female development; removal of
w
Fem results in all-male offspring. This is the first study that demonstrates an interaction between MD and
Wolbachia
feminization, and it highlights endosymbionts as potentially confounding factors in MD of sex chromosomes.
Molecular evolution of the hyaluronan synthase 2 gene in mammals: implications for adaptations to the subterranean niche and cancer resistance
Authors: Faulkes Christopher G. , Davies Kalina T. J. , Rossiter Stephen J. , Bennett Nigel C.
Published: May 2015

The naked mole-rat (NMR)
Heterocephalus glaber
is a unique and fascinating mammal exhibiting many unusual adaptations to a subterranean lifestyle. The recent discovery of their resistance to cancer and exceptional longevity has opened up new and important avenues of research. Part of this resistance to cancer has been attributed to the fact that NMRs produce a modified form of hyaluronan—a key constituent of the extracellular matrix—that is thought to confer increased elasticity of the skin as an adaptation for living in narrow tunnels. This so-called high molecular mass hyaluronan (HMM-HA) stems from two apparently unique substitutions in the hyaluronan synthase 2 enzyme (HAS2). To test whether other subterranean mammals with similar selection pressures also show molecular adaptation in their
HAS2
gene, we sequenced the
HAS2
gene for 11 subterranean mammals and closely related species, and combined these with data from 57 other mammals. Comparative screening revealed that one of the two putatively important HAS2 substitutions in the NMR predicted to have a significant effect on hyaluronan synthase function was uniquely shared by all African mole-rats. Interestingly, we also identified multiple other amino acid substitutions in key domains of the HAS2 molecule, although the biological consequences of these for hyaluronan synthesis remain to be determined. Despite these results, we found evidence of strong purifying selection acting on the
HAS2
gene across all mammals, and the NMR remains unique in its particular HAS2 sequence. Our results indicate that more work is needed to determine whether the apparent cancer resistance seen in NMR is shared by other members of the African mole-rat clade.
Antioxidants safeguard telomeres in bold chicks
Authors: Kim Sin-Yeon , Velando Alberto
Published: May 2015

Telomeres are sensitive to damage induced by oxidative stress, and thus it is expected that dietary antioxidants may support the maintenance of telomere length in animals, particularly those with a fast rate of life (e.g. fast metabolism, activity and growth). We tested experimentally the effect of antioxidant supplements on telomere length during early development in wild gull chicks with natural individual variations in behaviour pattern and growth rate. Proactive chicks had shorter telomeres than reactive chicks, but the penalty for the bold behaviour pattern was reduced by antioxidant supplementation. Chicks growing faster had longer telomeres during early growth, suggesting that inherited quality supports a fast life history.
Bacillus crescens sp. nov., isolated from soil
Authors: Shivani Y. , Subhash Y. , Dave. Bharti P. , Sasikala Ch. , Ramana Ch. V.
Published: May 2015

Two bacterial strains (JC247T and JC248) were isolated from soil samples collected from Rann of Kutch, Gujarat, India. Colonies of both strains were creamy white. Cells were Gram-stain-positive, rods-to-curved rods (crescent-shaped), and produced centrally located oval-shaped endospores. Major (>5 %) fatty acids of both strains were iso-C16 
: 
0, iso-C14 
: 
0, iso-C15 
: 
0, C16 
: 
1ω11c and C16 
: 
0, with minor ( < 5 but >1 %) amounts of anteiso-C15 
: 
0, anteiso-C17 
: 
0, iso-C16 
: 
1 H, iso-C17 
: 
0, iso-C18 
: 
0, C14 
: 
0, C17 
: 
0, C18 
: 
0, C18 
: 
1ω9c, iso-C17 
: 
1ω10c and anteiso-C17 
: 
0B/isoI. Diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were the major polar lipids of both strains. Cell-wall amino acids were l-alanine, d-alanine, d-glutamic acid and meso-diaminopimelic acid. The genomic DNA G+C content of strains JC247T and JC248 was 48.2 and 48.1 mol%, respectively. Both strains were closely related with mean DNA–DNA hybridization >90 %. 16S rRNA gene sequence analysis of both strains indicated that they are members of the genus Bacillus within the family Bacillaceae of the phylum Firmicutes. Both strains had a 16S rRNA gene sequence similarity of 96.93 % with Bacillus firmus NCIMB 9366T and < 96.92 % with other members of the genus Bacillus. Sequence similarity between strain JC247T and JC248 was 100 %. Distinct morphological, physiological and genotypic differences from previously described taxa support the classification of strains JC247T and JC248 as representatives of a novel species of the genus Bacillus, for which the name Bacillus
crescens sp. nov. is proposed. The type strain is JC247T ( = KCTC 33627T = LMG 28608T).
Palleronia soli sp. nov., isolated from a soil sample on reclaimed tidal land, and emended description of the genus Palleronia
Authors: Kim Yena , Kim Jong-Hwa , Lee Keun Chul , Lee Jung-Sook , Kim Wonyong
Published: May 2015

A Gram-stain-negative, strictly aerobic, non-motile, non-spore-forming, short rod-shaped and moderately halophilic bacterial strain, CAU 1105T, was isolated from soil on reclaimed tidal land in Modo, Republic of Korea, and its taxonomic position was investigated using a polyphasic approach. Strain CAU 1105T grows optimally at a temperature of 37 °C at pH 7 in the presence of 3 % (w/v) sea salt. Based on 16S rRNA gene sequence similarity analyses, the novel isolate was assigned to the genus Palleronia within the class Alphaproteobacteria and showed the highest 16S rRNA gene sequence similarity with Palleronia marisminoris B33T (95.4 %). Strain CAU 1105T contained ubiquinone-10 as the only respiratory quinone and C18 : 1ω7c as the major cellular fatty acid. The DNA G+C content of strain CAU 1105T was 64.3 mol%. On the basis of phenotypic differentiation, phylogenetic and chemotaxonomic data, strain CAU 1105T represents a novel species of the genus Palleronia, for which the name Palleronia
soli sp. nov. is proposed. The type strain is CAU 1105T ( = KCTC 42298T = NBRC 110740T). An emended description of the genus Palleronia is also provided.
A Chronological Atlas of Natural Selection in the Human Genome during the Past Half-million Years
Authors: Zhou Hang , Hu Sile , Matveev Rostislav , Yu Qianhui , Li Jing , Khaitovich Philipp , Jin Li , Lachmann Michael , Stoneking Mark , Fu Qiaomei , Tang Kun
Published: May 2015

The spatiotemporal distribution of recent human adaptation is a long standing question. We developed a new coalescent-based method that collectively assigned human genome regions to modes of neutrality or to positive, negative, or balancing selection. Most importantly, the selection times were estimated for all positive selection signals, which ranged over the last half million years, penetrating the emergence of anatomically modern human (AMH). These selection time estimates were further supported by analyses of the genome sequences from three ancient AMHs and the Neanderthals. A series of brain function-related genes were found to carry signals of ancient selective sweeps, which may have defined the evolution of cognitive abilities either before Neanderthal divergence or during the emergence of AMH. Particularly, signals of brain evolution in AMH are strongly related to Alzheimer’s disease pathways. In conclusion, this study reports a chronological atlas of natural selection in Human.
Surface-driven registration method for the structure-informed segmentation of diffusion MR images
Authors: Esteban Oscar , Zosso Dominique , Daducci Alessandro , Bach-Cuadra Meritxell , Ledesma-Carbayo María J. , Thiran Jean-Philippe , Santos Andres
Published: May 2015

Current methods for processing diffusion MRI (dMRI) to map the connectivity of the human brain require precise delineations of anatomical structures. This requirement has been approached by either segmenting the data in native dMRI space or mapping the structural information from T1-weighted (T1w) images. The characteristic features of diffusion data in terms of signal-to-noise ratio, resolution, as well as the geometrical distortions caused by the inhomogeneity of magnetic susceptibility across tissues hinder both solutions. Unifying the two approaches, we proposeregseg, a surface-to-volume nonlinear registration method that segments homogeneous regions within multivariate images by mapping a set of nested reference-surfaces. Accurate surfaces are extracted from a T1w image of the subject, using as target image the bivariate volume comprehending the fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) maps derived from the dMRI dataset. We first verify the accuracy ofregsegon a general context using digital phantoms distorted with synthetic and random deformations. Then we establish an evaluation framework using undistorted dMRI data from the Human Connectome Project (HCP) and realistic deformations derived from the inhomogeneity fieldmap corresponding to each subject. We analyze the performance ofregsegcomputing the misregistration error of the surfaces estimated after being mapped withregsegonto 16 datasets from the HCP. The distribution of errors shows a 95% CI of 0.56–0.66 mm, that is below the dMRI resolution (1.25 mm, isotropic). Finally, we cross-compare the proposed tool against a nonlinearb0-to-T2w registration method, thereby obtaining a significantly lower misregistration error withregseg. The accurate mapping of structural information in dMRI space is fundamental to increase the reliability of network building in connectivity analyses, and to improve the performance of the emerging structure-informed techniques for dMRI data processing.
Theoretical consequences of the Mutagenic Chain Reaction for manipulating natural populations
Authors: Unckless Robert , Messer Philipp , Clark Andrew
Published: May 2015

The use of recombinant genetic technologies for population manipulation has mostly remained an abstract idea due to the lack of a suitable means to drive novel gene constructs to high frequency in populations. Recently Gantz and Bier showed that the use of CRISPR/Cas9 technology could provide an artificial drive mechanism, the so-called Mutagenic Chain Reaction (MCR), which could lead to rapid fixation of even a deleterious introduced allele. We establish the equivalence of this system to models of meiotic drive and review the results of simple models showing that, when there is a fitness cost to the MCR allele, an internal equilibrium exists that is usually unstable. Introductions must be at a frequency above this critical point for the successful invasion of the MCR allele. These modeling results have important implications for application of MCR in natural populations.
The crystal structure, luminescence and nitrobenzene-sensing properties of a two-dimensional MnIIcoordination polymer based on 2,6-bis(imidazol-1-yl)pyridine
Authors: Wang Yin-Lin , Long Ling-Liang , Zhang Jin-Fang
Published: May 2015

A two-dimensional MnIIcoordination polymer (CP), poly[bis[μ2-2,6-bis(imidazol-1-yl)pyridine-κ2N3:N3′]bis(thiocyanato-κN)manganese] [Mn(NCS)2(C11H9N5)2]n, (I), has been obtained by the self-assembly reaction of Mn(ClO4)2·6H2O, NH4SCN and bent 2,6-bis(imidazol-1-yl)pyridine (2,6-bip). CP (I) was characterized by FT–IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The crystal structure features a unique two-dimensional (4,4) network with one-dimensional channels. The luminescence and nitrobenzene-sensing properties were explored in a DMF suspension, revealing that CP (I) shows a strong luminescence emission and is highly sensitive for nitrobenzene detection.
Crystal structure of 5-(4-methylphenyl)-3-[(E)-2-(4-methylphenyl)ethenyl]cyclohex-2-en-1-one
Authors: Mague Joel T. , Mohamed Shaaban K. , Akkurt Mehmet , Abdelhamid Antar A. , Albayati Mustafa R.
Published: May 2015

In the title compound, C22H22O, the dihedral angle between the planes of the benzene rings is 53.55 (7)°. Weak C—H...O interactions help to direct the packing, forming sheets lying parallel to (020).
Crystal structure of (E)-2-hydroxy-4′-methoxyazastilbene
Authors: Chantrapromma Suchada , Kaewmanee Narissara , Boonnak Nawong , Chantrapromma Kan , Ghabbour Hazem A. , Fun Hoong-Kun
Published: May 2015

The title azastilbene derivative, C14H13NO2{systematic name: (E)-2-[(4-methoxybenzylidene)amino]phenol}, is a product of the condensation reaction between 4-methoxybenzaldehyde and 2-aminophenol. The molecule adopts anEconformation with respect to the azomethine C=N bond and is almost planar, the dihedral angle between the two substituted benzene rings being 3.29 (4)°. The methoxy group is coplanar with the benzene ring to which it is attached, the Cmethyl—O—C—C torsion angle being −1.14 (12)°. There is an intramolecular O—H...N hydrogen bond generating anS(5) ring motif. In the crystal, molecules are linkedviaC—H...O hydrogen bonds, forming zigzag chains along [10-1]. The chains are linkedviaC—H...π interactions, forming a three-dimensional structure.
Crystal structure of hexaaquadichloridoytterbium(III) chloride
Authors: Knopf Kevin M. , Crundwell Guy , Westcott Barry L.
Published: May 2015

The crystal structure of the title compound, [YbCl2(H2O)6]Cl, was determined at 110 K. Samples were obtained from evaporated acetonitrile solutions containing the title compound, which consists of a [YbCl2(H2O)6]+cation and a Cl−anion. The cations in the title compound sit on a twofold axis and form O—H...Cl hydrogen bonds with the nearby Cl−anion. The coordination geometry around the metal centre forms a distorted square antiprism. The ytterbium complex is isotypic with the europium complex [Tambrorninoet al.(2014).Acta Cryst.E70, i27].
Designing catastrophic bonds for catastrophic risks in agriculture
Authors: Sun Lin , Turvey Calum G. , Jarrow Robert A.
Published: May 2015

Purpose

– The purpose of this paper is to outline a pricing formula for the valuation of catastrophic (CAT) bonds as applied to multiple trigger drought risks in Kenya.

Design/methodology/approach

– The valuation model is designed around the multiple triggers of the Mexican Catastrophe bonds, but the valuation model is based on Jarrow’s (2010) closed form CAT Bond Pricing model. The authors outline the model structure, the multiple tranches with rainfall triggers, and simulate the model using Monte Carlo methods. Data input was synthesized from historical rainfall data in Kenya’s Moyale region as well as prevailing LIBOR and rates and conventional coupons.

Findings

– The authors compute the valuation model using Monte Carlo techniques. The authors found the pricing method to be robust and consistent under various parameter settings including trigger levels, time after launch, recovery rates, coupon spreads, and zero coupon curves. For example the higher the trigger rates, the lower will be the bond price at issue. With 50 percent recovery the CAT bond at issue would be around $702 with a high triggers and 976 with low triggers, but the valuation changes with parameters.

Practical implications

– As far as the authors know the use of multiple trigger CAT bonds has been very limited in practice. The valuation formula and methods outlined in this paper show how CAT bonds can be effectively designed to address CAT covariate risks in developing agricultural economies.

Originality/value

– This paper examines CAT bonds to investigate multi-trigger rainfall risks in Kenya. The paper shows how CAT bonds can be designed to meet specific and CAT risks. Using Jarrow’s (2010) closed form solution this paper is one of the first to apply it to the macro-management of agricultural risks.
Behavioral economic insights on index insurance design
Authors: Carter Michael , Elabed Ghada , Serfilippi Elena
Published: May 2015

Purpose

– While behavioral economic experiments have uncovered a wealth of insights concerning how people decide in the face of risk and uncertainty, the implications of these insights for the demand for agricultural insurance are under-explored. The purpose of this paper is to report on results from two recent field experiments that measure the extent to which farmer behavior departs from the predictions of expected utility theory and derives the implications of these departures for insurance demand.

Design/methodology/approach

– Framed behavioral field experiments were played with random samples of West African Cotton farmers who lived in areas that were being incorporated into a cotton insurance pilot program.

Findings

– Substantial numbers of farmers depart from expected utility behavior in ways that predict excess sensitivity to uncovered basis risk in insurance contracts; and, the fact that insurance premiums are typically framed as certain and unavoidable, while benefits are unknown and stochastic.

Originality/value

– Using novel field experimental methods, the work summarized here indicates that more careful design of index insurance contracts in conformity with the findings of behavioral economics could result in larger contract uptake and, ultimately, larger development impacts.
Challenges in the design of crop revenue insurance
Authors: Goodwin Barry K.
Published: May 2015

Purpose

– The federal crop insurance program has become the cornerstone of US agricultural policy. Since its introduction in the mid-1990s, crop revenue insurance has grown in prominence and now represents nearly 90 percent of liability for major crops. The pricing and design of revenue insurance raises a number of important challenges. The 2014 Farm Bill brought about several important changes in the program, resulting in a moving target for analysts and researchers. The paper aims to discuss these issues.

Design/methodology/approach

– The risks are of a multivariate nature and are likely to be highly dependent on one another. The crop insurance setting is also constantly changing, with technological changes in production practices and highly volatile commodity prices. Compounding these challenges is the fact that US policymakers continually change the program.

Findings

– The program has indeed undergone many changes and a number of important research questions need to be addressed.

Originality/value

– Original research based upon recent policy.