bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-dimensional MoS2 under ion irradiation: from controlled defect production to electronic structure engineering
Authors: Ghorbani-Asl Mahdi , Kretschmer Silvan , Spearot Douglas E , Krasheninnikov Arkady V
Published: April 2017

Two-dimensional (2D) transition metal dichalcogenides (TMDs), like MoS2, have unique electronic and optical properties, which can further be tuned using ion bombardment and post-synthesis ion-beam mediated methods combined with exposure of the irradiated sample to precursor gases. The optimization of these techniques requires a complete understanding of the response of 2D TMDs to ion irradiation, which is affected by the reduced dimensionality of the system. By combining analytical potential molecular dynamics with first-principles calculations, we study the production of defects in free-standing MoS2 sheets under noble gas ion irradiation for a wide range of ion energies when nuclear stopping dominates, and assess the probabilities for different defects to appear. We show that depending on the incident angle, ion type and energy, sulfur atoms can be sputtered away predominantly from the top or bottom layers, creating unique opportunities for engineering mixed MoSX compounds where X are chemical elements from group V or VII. We study the electronic structure of such systems, demonstrate that they can be metals, and finally discuss how metal/semiconductor/metal junctions, which exhibit negative differential resistance, can be designed using focused ion beams combined with the exposure of the system to fluorine.
Iterated socles and integral dependence in regular rings
Authors: Corso Alberto , Goto Shiro , Huneke Craig , Polini Claudia , Ulrich Bernd
Published: April 2017

Let

R
R

be a formal power series ring over a field, with maximal ideal

m

\mathfrak {m}

, and let

I
I

be an ideal of

R
R

. We study iterated socles of

I
I

, that is, ideals of the form

I

:
R

m

s

I :_R {\mathfrak m}^s

for positive integers

s
s

. We are interested in iterated socles in connection with the notion of integral dependence of ideals. In this article we show that iterated socles are integral over

I
I

, with reduction number at most one, provided

s
≤
o
(

I
1

(

φ
d

)
)
−
1

s \leq \text {o}(I_1(\varphi _d))-1

, where

o
(

I
1

(

φ
d

)
)

\text {o}(I_1(\varphi _d))

is the order of the ideal of entries of the last map in a minimal free

R
R

-resolution of

R

/

I

R/I

. In characteristic zero, we also provide formulas for the generators of iterated socles whenever

s
≤
o
(

I
1

(

φ
d

)
)

s\leq \text {o}(I_1(\varphi _d))

. This result generalizes previous work of Herzog, who gave formulas for the socle generators of any homogeneous ideal

I
I

in terms of Jacobian determinants of the entries of the matrices in a minimal homogeneous free

R
R

-resolution of

R

/

I

R/I

. Applications are given to iterated socles of determinantal ideals with generic height. In particular, we give surprisingly simple formulas for iterated socles of height two ideals in a power series ring in two variables. The generators of these socles are suitable determinants obtained from the Hilbert-Burch matrix.
Trajectories in interlaced integral pencils of 3-dimensional analytic vector fields are o-minimal
Authors: Le Gal Olivier , Sanz Fernando , Speissegger Patrick
Published: April 2017

Let

ξ
\xi

be an analytic vector field at

(

R

3

,
0
)

(\mathbb {R}^3,0)

and

I

\mathcal {I}

be an analytically non-oscillatory integral pencil of

ξ
\xi

; i.e.,

I

\mathcal {I}

is a maximal family of analytically non-oscillatory trajectories of

ξ
\xi

at 0 all sharing the same iterated tangents. We prove that if

I

\mathcal {I}

is interlaced, then for any trajectory

Γ
∈

I

\Gamma \in \mathcal {I}

, the expansion

R

a
n

,
Γ

\mathbb {R}_{\mathrm {an},\Gamma }

of the structure

R

a
n

\mathbb {R}_{\mathrm {an}}

by

Γ
\Gamma

is model-complete, o-minimal and polynomially bounded.
On the strict monotonicity of the first eigenvalue of the 𝑝-Laplacian on annuli
Authors: Anoop T. V. , Bobkov Vladimir , Sasi Sarath
Published: April 2017

Let

B
1

B_1

be a ball in

R

N

\mathbb {R}^N

centred at the origin and let

B
0

B_0

be a smaller ball compactly contained in

B
1

B_1

. For

p
∈
(
1
,
∞
)

p\in (1, \infty )

, using the shape derivative method, we show that the first eigenvalue of the

p
p

-Laplacian in annulus

B
1

∖

B
0

¯

B_1\setminus \overline {B_0}

strictly decreases as the inner ball moves towards the boundary of the outer ball. The analogous results for the limit cases as

p
→
1

p \to 1

and

p
→
∞

p \to \infty

are also discussed. Using our main result, further we prove the nonradiality of the eigenfunctions associated with the points on the first nontrivial curve of the Fučik spectrum of the

p
p

-Laplacian on bounded radial domains.
PreMosa: extracting 2D surfaces from 3D microscopy mosaics
Authors: Blasse Corinna , Saalfeld Stephan , Etournay Raphaël , Sagner Andreas , Eaton Suzanne , Myers Eugene W
Published: April 2017

Motivation

A significant focus of biological research is to understand the development, organization and function of tissues. A particularly productive area of study is on single layer epithelial tissues in which the adherence junctions of cells form a 2D manifold that is fluorescently labeled. Given the size of the tissue, a microscope must collect a mosaic of overlapping 3D stacks encompassing the stained surface. Downstream interpretation is greatly simplified by preprocessing such a dataset as follows: (i) extracting and mapping the stained manifold in each stack into a single 2D projection plane, (ii) correcting uneven illumination artifacts, (iii) stitching the mosaic planes into a single, large 2D image and (iv) adjusting the contrast.

Results

We have developed PreMosa, an efficient, fully automatic pipeline to perform the four preprocessing tasks above resulting in a single 2D image of the stained manifold across which contrast is optimized and illumination is even. Notable features are as follows. First, the 2D projection step employs a specially developed algorithm that actually finds the manifold in the stack based on maximizing contrast, intensity and smoothness. Second, the projection step comes first, implying all subsequent tasks are more rapidly solved in 2D. And last, the mosaic melding employs an algorithm that globally adjusts contrasts amongst the 2D tiles so as to produce a seamless, high-contrast image. We conclude with an evaluation using ground-truth datasets and present results on datasets from Drosophila melanogaster wings and Schmidtae mediterranea ciliary components.

Availability and Implementation

PreMosa is available under https://cblasse.github.io/premosa

Supplementary information

Supplementary data are available at Bioinformatics online.
Radicalisation, Community and the Politics of Protest in the Spanish Second Republic: Asturias, 1931–34
Authors: Kerry Matthew
Published: April 2017

In October 1934 thousands of leftists took up arms in a two-week revolutionary insurrection in the northern Spanish region of Asturias which shook the Second Republic (1931–1936) and formed part of a critical European juncture of protest in 1934. This article rethinks the process of radicalisation—a key process for understanding both the insurrection and the wider polarisation of Spanish society prior to the Civil War—in the context of the Asturian coalfields. I argue that radicalisation, understood as a more militant, confrontational mode of politics, rather than as having any particular ideological content, needs to be located in the struggles, divisions and anxieties at a local level, shaped by understandings of community, within the wider national and international context. Increased tension and confrontation was due to a combination of factors, including competition amongst different leftist groups to present themselves as the most anticlerical, alienation from the main mining union, anxieties over the perceived emergence of fascism, and a spiral of protest and repression shaped by a more heavy-handed state policing strategy in 1934. The interplay of social and political factors provided the energy behind the revolutionary insurrection. This serves to re-evaluate the process of radicalisation in the Second Republic, and the politics and struggles of the working class in a dark and tumultuous decade for the European left.
Enhanced biological activities of gamma-irradiated persimmon leaf extract
Authors: Cho Byoung-Ok , Nchang Che Denis , Yin Hong-Hua , Jang Seon-Il
Published: April 2017

The aim of this study was to compare the anti-oxidative and anti-inflammatory activities of gamma-irradiated persimmon leaf extract (GPLE) with those of non-irradiated persimmon leaf extract (PLE). Ethanolic extract of persimmon leaf was exposed to gamma irradiation at a dose of 10 kGy. After gamma irradiation, the color of the extract changed from dark brown to light brown. The anti-oxidative and anti-inflammatory activities of GPLE and PLE were assessed from: total polyphenol and total flavonoid contents; 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay; 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay, and levels of pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). The total polyphenol contents of GPLE and PLE were determined to be 224.44 ± 1.54 and 197.33 ± 5.81 mg gallic acid equivalents (GAE)/g, respectively, and the total flavonoid contents of GPLE and PLE were 206.27 ± 1.15 and 167.60 ± 2.00 mg quercetin equivalents (QUE)/g, respectively. The anti-oxidant activities of GPLE and PLE as measured by DPPH assays were 338.33 ± 30.19 μg/ml (IC50) and 388.68 ± 8.45 μg/ml (IC50), respectively, and those measured by ABTS assays were 510.49 ± 15.12 μg/ml (IC50) and 731.30 ± 10.63 μg/ml (IC50), respectively. IC50 is the inhibitor concentration that reduces the response by 50%. GPLE strongly inhibited the production of NO, PGE2 and IL-6 compared with PLE in lipopolysaccharide-stimulated RAW264.7 macrophages. Furthermore, GPLE significantly inhibited the production of TNF-α and IL-6 cytokines compared with PLE in phorbol 12-myristate 13-acetate (PMA) plus A23187-stimulated HMC-1 human mast cells. These results indicate that gamma irradiation of PLE can enhance its anti-oxidative and anti-inflammatory activities through elevation of the phenolic contents. Therefore, gamma-irradiated PLE has potential for use in the food and cosmetic industries.
Characterization of relative biological effectiveness for conventional radiation therapy: a comparison of clinical 6 MV X-rays and 137Cs
Authors: Howard Michelle , Beltran Chris , Sarkaria Jann , Herman Michael G
Published: April 2017

Various types of radiation are utilized in the treatment of cancer. Equal physical doses of different radiation types do not always result in the same amount of biological damage. In order to account for these differences, a scaling factor known as the relative biological effectiveness (RBE) can be used. 137Cesium (137Cs) has been used as a source of radiation in a significant body of radiation therapy research. However, high-energy X-rays, such as 6 MV X-rays, are currently used clinically to treat patients. To date, there is a gap in the literature regarding the RBE comparison of these two types of radiation. Therefore, the purpose of this study was to investigate the RBE of 137Cs relative to that of 6 MV X-rays. To determine the RBE, five cell lines were irradiated [Chinese hamster ovary (CHO); human lung adenocarcinoma (A549); human glioma (U251); human glioma (T98); and human osteosarcoma (U2OS)] by both types of radiation and assessed for cell survival using a clonogenic assay. Three of the five cell lines resulted in RBE values of ~1.00 to within 11% for all survival fractions, showing the physical and biological dose for these two types of radiation were equivalent. The other two cell lines gave RBE values differing from 1.00 by up to 36%. In conclusion, the results show the range in biological effect seen between cell lines, and therefore cell type must be considered when characterizing RBE.
Discovery of a distant molecular cloud in the extreme outer Galaxy with the Nobeyama 45 m telescope
Authors: Matsuo Mitsuhiro , Nakanishi Hiroyuki , Minamidani Tetsuhiro , Torii Kazufumi , Saito Masao , Kuno Nario , Sawada Tsuyoshi , Tosaki Tomoka , Kobayashi Naoto , Yasui Chikako , Mito Hiroyuki , Hasegawa Takashi , Hirota Akihiko
Published: April 2017

We report the discovery of a molecular cloud whose kinematic distance is the largest in the Galaxy at the present moment, named G213.042+0.003, at l = 213${^{\circ}_{.}}$042 and b = 0${^{\circ}_{.}}$003 in the 12CO(J = 1–0) line using the Nobeyama 45 m telescope and the BEARS multi-beam receiver. This molecular cloud is located at a heliocentric distance of $21_{-7}^{+12}\:$kpc and Galactocentric distance of 29$_{-7}^{+12}\:$kpc, which are estimated as the kinematic distances with the Galactic parameters obtained by Reid et al. (2014, ApJ, 783, 130). Its major and minor diameters and line width were measured to be $4.0_{-1.3}^{+2.3}\:$pc, 3.0$_{-1.0}^{+1.7}\:$pc, and 1.5 km s−1, respectively. The cloud mass was estimated to be 2.5$_{-1.4}^{+3.7}$ × 102 M⊙ using the CO-to-H2 conversion factor of 5.6 × 1020 cm−2 (K km s−1)−1 obtained in the far outer Galaxy.
Operating room team member role affects room traffic in orthopaedic surgery: a prospective observational study
Authors: DiBartola Alex C. , Patel Priya G. , Scharschmidt Thomas J. , Mayerson Joel L. , Phieffer Laura S. , Glassman Andrew H. , Moffatt-Bruce Susan D. , Quatman Carmen E.
Published: April 2017

Background:

Operating room (OR) traffic is an increasing topic of concern for potential risks of surgical site infections (SSIs). We evaluated room traffic rates during orthopaedic surgery cases to better understand how OR team member roles contribute to room traffic. Our hypothesis was that OR traffic differs among team member groups.

Methods:

We evaluated 46 orthopaedic surgery cases involving implantation of a device at an academic medical center during the summer of 2015. Room traffic rates were recorded as the number of door openings per minute in each case. OR team member groups were defined as follows: Group (A) charge nurse, nurse, scrub technician, scrub technician student; (B) anesthesiology attending physician, anesthesiology resident, anesthesiology medical student, certified nurse anesthetist; (C) orthopaedic surgery attending, orthopaedic surgery resident, orthopaedic surgery medical student; (D) medical sales representative/vendor; (E) radiology technician.

Results:

The number of door openings ranged from 48 to 259 (mean 127±47). The overall mean room traffic rate per minute per case ranged from 0.2193-1.014 (mean 0.5856±0.1663). Operative length ranged from 90–521 min (mean 226±89.1). There was a statistically significance difference between the median room traffic rate per minute per case by different group (A, B, C, D, and E) types (χ

2

(4)
=127.085, P=0.0001).

Conclusions:

Room traffic rates and number of door openings per case are different among different OR team member groups. Better understanding of room traffic characteristics allows for strategic intervention to decrease room traffic among team members in each group.
Axial spondyloarthritis classification criteria: the debate continues
Authors: Dubreuil Maureen , Deodhar Atul A.
Published: April 2017

Purpose of review

The Assessment of Spondyloarthritis International Society (ASAS) axial spondyloarthritis (axSpA) classification criteria marked a major step forward in SpA research, distinguishing axial from peripheral disease, and allowing earlier identification through MRI. This facilitated all aspects of research including epidemiology, therapeutics and patient outcomes.

Recent findings

The ASAS axSpA classification criteria have been applied broadly in research, and were validated in a recent meta-analysis of international studies. Concerns arose because of clinical differences between the clinical and imaging arms, which imply different risk for radiographic progression, and perform differently in validation studies. Low specificity of the MRI finding of sacroiliac joint bone marrow edema may lead to misclassification in populations with low axSpA prevalence. We suggest methodology to improve upon the criteria, including rigorous assessment of potential candidate criteria sets, discrete choice experiments to allow consideration of feature weights, and validation. Separately, assessment of structural and inflammatory MRI abnormalities should be performed to refine the MRI definition of sacroiliitis.

The debate regarding the validation and modification of the ASAS axSpA classification criteria should lead to international efforts to build upon the gains made by these criteria, to further refine the axSpA population definitions for research and ultimately improve patient outcomes.
The effect of persistent toe walking on the skeletal development of the pediatric foot and ankle
Authors: Sinclair Mark R. , Lind Allison A. , Knowlton Joshua Q.
Published: April 2017

The aim of this study was to determine whether persistent idiopathic toe walking leads to compensatory skeletal changes in the pediatric foot and ankle. Foot radiographs of children diagnosed with idiopathic toe walking and sex-matched and age-matched controls were retrospectively reviewed. Five blinded providers assessed the foot radiographs for skeletal changes to the ankle. The relationship between each measure and toe-walking status was examined. Providers observed radiographic evidence of skeletal changes of the talus in idiopathic toe walkers compared with controls, suggesting that persistent toe walking impacts the skeletal development of the talus. Level of Evidence: prognostic level III
The effect of continuous intrathecal baclofen therapy on ambulatory children with cerebral palsy
Authors: Pruszczynski Blazej , Sees Julieanne , Hulbert Robert , Church Chris , Henley John , Niiler Tim , Miller Freeman
Published: April 2017

The effect of a continuous intrathecal infusion of baclofen (CITB) was retrospectively studied in 19 ambulatory children with cerebral palsy (aged 12.4±4.9 years at CITB initiation). The mean clinical follow-up was 5.1±2.4 years and the mean follow-up gait analysis was 2.8±1.9 years. Spastic cerebral palsy diagnosis [14 (74%)] was most frequent. Most patients [11 (58%)] were Gross Motor Function Classification System level III. CITB significantly improved muscle tone and knee flexion at initial contact (P<0.05), but it did not lead to improved gait speed or gross motor function.
Radiopaque Element to Evaluate Adequacy of Debridement of Bony Lesions
Authors: Pulos Nicholas , Shin Alexander Y.
Published: April 2017

A technique for using an x-ray detectable radiopaque element from a surgical sponge to assess the adequacy of debridement of carpal bone cysts, Kienböck disease (lunate avascular necrosis), enchondroma of the digits, and scaphoid nonunions is described. The technique is simple to perform, inexpensive, and presents minimal additional risk to the patient. The technique has been used over the past 16 years and has enabled adequate debridement of these hand and wrist maladies by radiographically demonstrating the adequacy of the debridement to be bone grafted. It avoids the problems associated with liquid contrast dye and has proven to be very safe, effective, and inexpensive.
The Children's Health Exposure Analysis Resource: enabling research into the environmental influences on children's health outcomes
Authors: Balshaw David M. , Collman Gwen W. , Gray Kimberly A. , Thompson Claudia L.
Published: April 2017

Purpose of review

The Children's Health Exposure Analysis Resource (CHEAR) is a new infrastructure supported by the National Institute of Environmental Health Sciences to expand the ability of children's health researchers to include analysis of environmental exposures in their research and to incorporate the emerging concept of the exposome.

Recent findings

There is extensive discussion of the potential of the exposome to advance understanding of the totality of environmental influences on human health. Children's health is a logical choice to demonstrate the exposome concept due to the extensive existing knowledge of individual environmental exposures affecting normal health and development and the short latency between exposures and observable phenotypes. Achieving this demonstration will require access to extensive analytical capabilities to measure a suite of exposures through traditional biomonitoring approaches and to cross-validate these with emerging exposomic approaches.

CHEAR is a full-service exposure assessment resource, linking up-front consultation with both laboratory and data analysis. Analyses of biological samples are intended to enhance studies by including targeted analysis of specific exposures and untargeted analysis of small molecules associated with phenotypic endpoints. Services provided by CHEAR are made available without cost but require a brief application and adherence to policies detailed on the CHEAR web page at https://chearprogram.org/.
Digestion of Human Milk Oligosaccharides by Bifidobacterium breve in the Premature Infant
Authors: Underwood Mark A. , Davis Jasmine C.C. , Kalanetra Karen M. , Gehlot Sanjay , Patole Sanjay , Tancredi Daniel J. , Mills David A. , Lebrilla Carlito B. , Simmer Karen
Published: April 2017

Objective:

The aim of this study was to measure consumption and absorption of human milk oligosaccharides (HMOs) in a cohort of premature infants treated with probiotic Bifidobacterium breve.

Methods:

Twenty‐nine premature infants (median gestational age 28 weeks, range 23–32 weeks) cared for in the neonatal intensive care unit of the King Edward and Princess Margaret Hospital in Perth, Australia, were treated with B breve at a dose of 1.66 billion organisms per day. Samples of feces, urine, and milk were obtained at initiation of the probiotic and again 3 weeks later. 16S ribosomal RNA from the feces was analyzed by next‐generation sequencing. Quantitation of HMO content of the milk, urine, and feces was performed using nano‐high‐performance liquid chromatography‐chip/time‐of‐flight mass spectrometry.

Results:

There was heterogeneity in colonization with bifidobacteria. “Responders” received milk with higher percentages of fucosylated HMOs and had higher percentages of bifidobacteria and lower percentages of Enterobacteriaceae in their feces than “nonresponders.” Several individual HMOs in the milk were associated with changes in fecal bifidobacteria over time. Changes over time in milk, fecal, and urine HMOs suggested heterogeneity among HMO structures in consumption by microbes in the gut lumen and absorption from the intestine.

Conclusions:

Colonization of the premature infant intestinal tract with probiotic B breve is influenced by prebiotic HMOs. B breve is a selective consumer of HMOs in the premature infant.
Potential of global croplands and bioenergy crops for climate change mitigation through deployment for enhanced weathering
Authors: Kantola Ilsa B. , Masters Michael D. , Beerling David J. , Long Stephen P. , DeLucia Evan H.
Published: April 2017

Conventional row crop agriculture for both food and fuel is a source of carbon dioxide (CO
2
) and nitrous oxide (N
2
O) to the atmosphere, and intensifying production on agricultural land increases the potential for soil C loss and soil acidification due to fertilizer use. Enhanced weathering (EW) in agricultural soils—applying crushed silicate rock as a soil amendment—is a method for combating global climate change while increasing nutrient availability to plants. EW uses land that is already producing food and fuel to sequester carbon (C), and reduces N
2
O loss through pH buffering. As biofuel use increases, EW in bioenergy crops offers the opportunity to sequester CO
2
while reducing fossil fuel combustion. Uncertainties remain in the long-term effects and global implications of large-scale efforts to directly manipulate Earth's atmospheric CO
2
composition, but EW in agricultural lands is an opportunity to employ these soils to sequester atmospheric C while benefitting crop production and the global climate.
Negative CO
2
emissions via enhanced silicate weathering in coastal environments
Authors: Meysman Filip J. R. , Montserrat Francesc
Published: April 2017

Negative emission technologies (NETs) target the removal of carbon dioxide (CO
2
) from the atmosphere, and are being actively investigated as a strategy to limit global warming to within the 1.5–2°C targets of the 2015 UN climate agreement. Enhanced silicate weathering (ESW) proposes to exploit the natural process of mineral weathering for the removal of CO
2
from the atmosphere. Here, we discuss the potential of applying ESW in coastal environments as a climate change mitigation option. By deliberately introducing fast-weathering silicate minerals onto coastal sediments, alkalinity is released into the overlying waters, thus creating a coastal CO
2
sink. Compared with other NETs, coastal ESW has the advantage that it counteracts ocean acidification, does not interfere with terrestrial land use and can be directly integrated into existing coastal management programmes with existing (dredging) technology. Yet presently, the concept is still at an early stage, and so two major research challenges relate to the efficiency and environmental impact of ESW. Dedicated experiments are needed (i) to more precisely determine the weathering rate under
in situ
conditions within the seabed and (ii) to evaluate the ecosystem impacts—both positive and negative—from the released weathering products.
Exploring the high-resolution mapping of gender-disaggregated development indicators
Authors: Bosco C. , Alegana V. , Bird T. , Pezzulo C. , Bengtsson L. , Sorichetta A. , Steele J. , Hornby G. , Ruktanonchai C. , Ruktanonchai N. , Wetter E. , Tatem A. J.
Published: April 2017

Improved understanding of geographical variation and inequity in health status, wealth and access to resources within countries is increasingly being recognized as central to meeting development goals. Development and health indicators assessed at national or subnational scale can often conceal important inequities, with the rural poor often least well represented. The ability to target limited resources is fundamental, especially in an international context where funding for health and development comes under pressure. This has recently prompted the exploration of the potential of spatial interpolation methods based on geolocated clusters from national household survey data for the high-resolution mapping of features such as population age structures, vaccination coverage and access to sanitation. It remains unclear, however, how predictable these different factors are across different settings, variables and between demographic groups. Here we test the accuracy of spatial interpolation methods in producing gender-disaggregated high-resolution maps of the rates of literacy, stunting and the use of modern contraceptive methods from a combination of geolocated demographic and health surveys cluster data and geospatial covariates. Bayesian geostatistical and machine learning modelling methods were tested across four low-income countries and varying gridded environmental and socio-economic covariate datasets to build 1×1 km spatial resolution maps with uncertainty estimates. Results show the potential of the approach in producing high-resolution maps of key gender-disaggregated socio-economic indicators, with explained variance through cross-validation being as high as 74–75% for female literacy in Nigeria and Kenya, and in the 50–70% range for many other variables. However, substantial variations by both country and variable were seen, with many variables showing poor mapping accuracies in the range of 2–30% explained variance using both geostatistical and machine learning approaches. The analyses offer a robust basis for the construction of timely maps with levels of detail that support geographically stratified decision-making and the monitoring of progress towards development goals. However, the great variability in results between countries and variables highlights the challenges in applying these interpolation methods universally across multiple countries, and the importance of validation and quantifying uncertainty if this is undertaken.
Voltage-dependent K+channels improve the energy efficiency of signalling in blowfly photoreceptors
Authors: Heras Francisco J. H. , Anderson John , Laughlin Simon B. , Niven Jeremy E.
Published: April 2017

Voltage-dependent conductances in many spiking neurons are tuned to reduce action potential energy consumption, so improving the energy efficiency of spike coding. However, the contribution of voltage-dependent conductances to the energy efficiency of analogue coding, by graded potentials in dendrites and non-spiking neurons, remains unclear. We investigate the contribution of voltage-dependent conductances to the energy efficiency of analogue coding by modelling blowfly R1-6 photoreceptor membrane. Two voltage-dependent delayed rectifier K+conductances (DRs) shape the membrane's voltage response and contribute to light adaptation. They make two types of energy saving. By reducing membrane resistance upon depolarization they convert the cheap, low bandwidth membrane needed in dim light to the expensive high bandwidth membrane needed in bright light. This investment of energy in bandwidth according to functional requirements can halve daily energy consumption. Second, DRs produce negative feedback that reduces membrane impedance and increases bandwidth. This negative feedback allows an active membrane with DRs to consume at least 30% less energy than a passive membrane with the same capacitance and bandwidth. Voltage-dependent conductances in other non-spiking neurons, and in dendrites, might be organized to make similar savings.
Characterization of RBP9 and RBP10, two developmentally regulated RNA-binding proteins in
Trypanosoma brucei
Authors: De Pablos Luis Miguel , Kelly Steve , de Freitas Nascimento Janaina , Sunter Jack , Carrington Mark
Published: April 2017

The fate of an mRNA is determined by its interaction with proteins and small RNAs within dynamic complexes called ribonucleoprotein complexes (mRNPs). In
Trypanosoma brucei
and related kinetoplastids, responses to internal and external signals are mainly mediated by post-transcriptional processes. Here, we used proximity-dependent biotin identification (BioID) combined with RNA-seq to investigate the changes resulting from ectopic expression of RBP10 and RBP9, two developmentally regulated RNA-binding proteins (RBPs). Both RBPs have reduced expression in insect procyclic forms (PCFs) compared with bloodstream forms (BSFs). Upon overexpression in PCFs, both proteins were recruited to cytoplasmic foci, co-localizing with the processing body marker SCD6. Further, both RBPs altered the transcriptome from a PCF- to a BSF-like pattern. Notably, upon expression of BirA*-RBP9 and BirA*-RBP10, BioID yielded more than 200 high confidence protein interactors (more than 10-fold enriched); 45 (RBP9) and 31 (RBP10) were directly related to mRNA metabolism. This study validates the use of BioID for investigating mRNP components but also illustrates the complexity of mRNP function.
Helicity conservation and twisted Seifert surfaces for superfluid vortices
Authors: Salman Hayder
Published: April 2017

Starting from the continuum definition of helicity, we derive from first principles its different contributions for superfluid vortices. Our analysis shows that an internal twist contribution emerges naturally from the mathematical derivation. This reveals that the spanwise vector that is used to characterize the twist contribution must point in the direction of a surface of constant velocity potential. An immediate consequence of the Seifert framing is that the continuum definition of helicity for a superfluid is trivially zero at all times. It follows that the Gauss-linking number is a more appropriate definition of helicity for superfluids. Despite this, we explain how a quasi-classical limit can arise in a superfluid in which the continuum definition for helicity can be used. This provides a clear connection between a microscopic and a macroscopic description of a superfluid as provided by the Hall–Vinen–Bekarevich–Khalatnikov equations. This leads to consistency with the definition of helicity used for classical vortices.
How (much) do flowers vary? Unbalanced disparity among flower functional modules and a mosaic pattern of morphospace occupation in the order Ericales
Authors: Chartier Marion , Löfstrand Stefan , von Balthazar Maria , Gerber Sylvain , Jabbour Florian , Sauquet Hervé , Schönenberger Jürg
Published: April 2017

The staggering diversity of angiosperms and their flowers has fascinated scientists for centuries. However, the quantitative distribution of floral morphological diversity (disparity) among lineages and the relative contribution of functional modules (perianth, androecium and gynoecium) to total floral disparity have rarely been addressed. Focusing on a major angiosperm order (Ericales), we compiled a dataset of 37 floral traits scored for 381 extant species and nine fossils. We conducted morphospace analyses to explore phylogenetic, temporal and functional patterns of disparity. We found that the floral morphospace is organized as a continuous cloud in which most clades occupy distinct regions in a mosaic pattern, that disparity increases with clade size rather than age, and that fossils fall in a narrow portion of the space. Surprisingly, our study also revealed that among functional modules, it is the androecium that contributes most to total floral disparity in Ericales. We discuss our findings in the light of clade history, selective regimes as well as developmental and functional constraints acting on the evolution of the flower and thereby demonstrate that quantitative analyses such as the ones used here are a powerful tool to gain novel insights into the evolution and diversity of flowers.
Dissolved organic carbon and unimodal variation in sexual signal coloration in mosquitofish: a role for light limitation?
Authors: Giery Sean T. , Layman Craig A.
Published: April 2017

Natural selection plays an important role in the evolution of sexual communication systems. Here, we assess the effect of two well-known selection agents, transmission environment and predation, on interpopulation variation in sexual signals. Our model system is a series of 21 populations of Bahamian mosquitofish subjected to independent variation in optical conditions and predation risk. We show that optically diverse environments, caused by locally variable dissolved organic carbon concentrations, rather than spatial variation in predation, drove divergence in fin coloration (fin redness). We found a unimodal pattern of phenotypic variation along the optical gradient indicating a threshold-type response of visual signals to broad variation in optical conditions. We discuss evolutionary and ecological mechanisms that may drive such a pattern as well as the implications of non-monotonic clines for evolutionary differentiation.
Olson's Extinction and the latitudinal biodiversity gradient of tetrapods in the Permian
Authors: Brocklehurst Neil , Day Michael O. , Rubidge Bruce S. , Fröbisch Jörg
Published: April 2017

The terrestrial vertebrate fauna underwent a substantial change in composition between the lower and middle Permian. The lower Permian fauna was characterized by diverse and abundant amphibians and pelycosaurian-grade synapsids. During the middle Permian, a therapsid-dominated fauna, containing a diverse array of parareptiles and a considerably reduced richness of amphibians, replaced this. However, it is debated whether the transition is a genuine event, accompanied by a mass extinction, or whether it is merely an artefact of the shift in sampling from the palaeoequatorial latitudes to the palaeotemperate latitudes. Here we use an up-to-date biostratigraphy and incorporate recent discoveries to thoroughly review the Permian tetrapod fossil record. We suggest that the faunal transition represents a genuine event; the lower Permian temperate faunas are more similar to lower Permian equatorial faunas than middle Permian temperate faunas. The transition was not consistent across latitudes; the turnover occurred more rapidly in Russia, but was delayed in North America. The argument that the mass extinction is an artefact of a latitudinal biodiversity gradient and a shift in sampling localities is rejected: sampling correction demonstrates an inverse latitudinal biodiversity gradient was prevalent during the Permian, with peak diversity in the temperate latitudes.
Dehydration bouts prompt increased activity and blood feeding by mosquitoes
Authors: Hagan Richard W. , Szuter Elise M. , Rosselot Andrew E. , Holmes Christopher J. , Siler Samantha C. , Rosendale Andrew J. , Hendershot Jacob M. , Elliott Kiaira S. B. , Jennings Emily C. , Rizlallah Alexandre E. , Xiao Yanyu , Watanabe Miki , Romick-Rosendale Lindsey E. , Rasgon Jason L. , Benoit Joshua B.
Published: April 2017

Mosquitoes are prone to dehydration and respond to this stress through multiple mechanisms, but previous studies have examined very specific responses and fail to provide an encompassing view of the role that dehydration has on mosquito biology. This study examined underlying changes in biology of the northern house mosquito,Culex pipiens, associated with short bouts of dehydration. We show that dehydration increased blood feeding propensity of mosquitoes, which was the result of both enhanced activity and a higher tendency to land on a host. Mosquitoes exposed to dehydrating conditions with access to water or rehydrated individuals experience no water loss and failed to display behavioral changes. RNA-seq and metabolome analyses following dehydration indicated that factors associated with energy metabolism are altered, specifically the breakdown of trehalose to yield glucose, which likely underlies changes in mosquito activity. Suppression of trehalose breakdown by RNA interference reduced phenotypes associated with dehydration. Comparable results were noted for two other mosquito species, suggesting this is a general response among mosquitoes. Lastly, field-based mesocosm studies usingC.pipiensrevealed that dehydrated mosquitoes were more likely to host feed, and disease modeling indicates dehydration bouts may increase transmission of West Nile virus. These results suggest that periods of dehydration prompt mosquitoes to utilize blood feeding as a mechanism to obtain water. This dehydration-induced increase in blood feeding is likely to intensify disease transmission during periods of low water availability.

Significance

Dehydration stress has substantial impacts on the biology of terrestrial invertebrates. To date, no studies have elucidated the difference between dehydration exposure and realized water loss in relation to mosquito behavior and physiology. Our experiments show that direct dehydration stress increases mosquito activity and subsequent blood feeding, likely as a mechanism to locate and utilize a bloodmeal for rehydration. These dehydration-induced phenotypes were linked to altered carbohydrate metabolism that acts as a source of energy. This study provides important insight into the impact of mosquito-dehydration dynamics on disease transmission that is likely general among mosquitoes.
Differential Effects of LIS1 On Processive Dynein-Dynactin Motility
Authors: Gutierrez Pedro A. , McKenney Richard J.
Published: April 2017

Cytoplasmic dynein is the primary minus-end directed microtubule motor protein in cells. LIS1 is a highly conserved dynein regulatory factor that binds directly to the dynein motor domain, uncoupling the enzymatic and mechanical cycles of the motor, and stalling dynein on the microtubule track. Dynactin, another ubiquitous dynein regulatory factor, acts to release dynein from an autoinhibited state, leading to a dramatic increase in fast, processive dynein motility. How these opposing activities are integrated to control dynein motility is unknown. Here we used fluorescence single-molecule microscopy to study the interaction of LIS1 with the processive dynein-dynactin-BicD2N (DDB) complex. Surprisingly, in contrast to the prevailing model for LIS1 function established in the context of dynein alone, we find that binding of LIS1 to DDB does not strongly disrupt processive motility. Motile DDB complexes bind up to two LIS1 dimers, and mutational analysis suggests LIS1 binds directly to the dynein motor domains during DDB movement. Interestingly, LIS1 enhances DDB velocity in a concentration dependent manner, in contrast to observations of LIS1’s effects on the motility of isolated dynein. Thus, LIS1 exerts concentration dependent effects on dynein motility, and can synergize with dynactin to enhance processive movement in the absence of load.
SPG20 mutation in three siblings with familial hereditary spastic paraplegia
Authors: Dardour Leila , Roelens Filip , Race Valerie , Souche Erika , Holvoet Maureen , Devriendt Koen
Published: April 2017

Troyer syndrome (MIM#275900) is an autosomal recessive form of complicated hereditary spastic paraplegia. It is characterized by progressive lower extremity spasticity and weakness, dysarthria, distal amyotrophy, developmental delay, short stature, and subtle skeletal abnormalities. It is caused by deleterious mutations in the SPG20 gene, encoding spartin, on Chromosome 13q13. Until now, six unrelated families with a genetically confirmed diagnosis have been reported. Here we report the clinical findings in three brothers of a consanguineous Moroccan family, aged 24, 17, and 7 yr old, with spastic paraplegia, short stature, motor and cognitive delay, and severe intellectual disability. Targeted exon capture and sequencing showed a homozygous nonsense mutation in the SPG20 gene, c.1369C>T (p.Arg457*), in the three affected boys.
Does foreign direct investment promote exports in China?
Authors: Li Xin , Chang Hsu Ling , Su Chi Wei , Dai Yin
Published: April 2017

Purpose

The purpose of this paper is to investigate the causal link between foreign direct investment (FDI) and exports in China based on the knowledge capital model (KK model, Markusen, 2002).

Design/methodology/approach

The bootstrap Granger full-sample and sub-sample rolling window causality test is used to determine whether FDI can promote exports.

Findings

The full-sample causality test indicates no causal relationship from FDI to exports. However, considering structural changes of exports and FDI, the authors’ find that the full-sample test is not reliable. Instead, the authors use the rolling window causality test to revisit the dynamic causal relationship, and the results present significant effects from FDI on exports, mostly around periods in which the proportion of FDI from Hong Kong, Macao and Taiwan is increasing. Specifically, positive impacts of FDI on exports are stronger than the negative impacts in China.

Research limitations/implications

The findings in this study suggest a significant time-varying nature of the correlation between FDI and exports. The promotion effect of FDI to exports is proved by the rolling window approach; it thus supports the KK model that divides FDI into lateral FDI and vertical FDI and proves that the constitution of FDI is critical to the relationship between FDI and exports.

Practical implications

China has been facing adjustment of its economic structure in recent years, and in this situation, increasing the proportion of FDI that can bring advanced production function is critical for the industrial structural adjustment.

Originality/value

This paper uses the bootstrap rolling window causality test to investigate the time-varying nature of the causality between FDI and exports, considering structural changes for the first time. The authors further deepen the previous research and draw a more realistic conclusion.
The spillover effect between CSI 500 index futures market and the spot market
Authors: Fan Xuejun , Du De
Published: April 2017

Purpose

Focusing on the spillover effects between the CSI 500 stock index futures market and its underlying spot market during April to September 2015, the purpose of this paper is to explore whether Chinese stock index futures should be responsible for the 2015 stock market crash.

Design/methodology/approach

Using both linear and non-linear econometric models, this paper empirically examines the mean spillover and the volatility spillover between the CSI 500 stock index futures market and the underlying spot market.

Findings

The results showed the following: the CSI 500 stock index futures market has significant one-way mean spillover effect on its spot market. The volatility in CSI 500 stock index futures market also has a significant positive spillover effect on its spot stock market, and the mean value of dynamic correlation coefficient between the two market volatility is 0.4848. The spillover effect of the CSI 500 stock index futures market on the underlying spot market is significantly asymmetric, characterized by relatively moderate and slow during the period of the markets rising, yet violent and rapid during the period of the markets falling. The findings suggest that although the stock index futures itself was not the “culprit” of Chinese stock market crash in 2015, its existence indeed accelerated and exacerbated the stock market’s decline under the imperfect trading system.

Originality/value

Different from the existing literature mainly focusing on CSI 300 stock index futures, this paper empirically examines the impact of the introduction of CSI 500 stock index futures on 2015 Chinese stock market crash for the first time.
Does the interactive quality of premium asset management service promote customers’ referral intentions? The moderating effect of customer’s asset size
Authors: Park Kyoo Bae , Park Min Jae
Published: April 2017

Purpose

The purpose of this paper is to investigate the asset size regarding how the level of a bank’s premium asset management service interaction quality influences the referral intention using performance expectation and customer satisfaction as mediators.

Design/methodology/approach

The study employs data collected from an anonymous survey on 185 customers who visited the PB centers. The study employs confirmatory factor analysis methods following a path analysis and structural equation modeling for testing research hypotheses with stepwise moderating effect test.

Findings

The results indicate that superiority in interaction quality of premium asset management services has a positive influence on customer satisfaction and performance expectations, and these quality factors also show a positive influence on the intent to maintain relationships and even referral intentions. The results also show that customers with larger asset sizes only have mediocre intentions to refer bank services to people around them.

Practical implications

Marketing positions, which remain faithful to the asset management obligation to fulfill a stable profit rate through constant interactive processes based on a trusting relationship between the customer and dedicated staff member that forms over time, can be a basis for service quality that can secure mid-to-long-term competition superiority in financial firms that offer asset management services.

Originality/value

This study focuses on whether interaction factors that form the quality of services for customized premium asset management through the bank’s dedicated staff member have a positive influence on customer satisfaction and referral intentions. Based on this analysis, the authors presented strategic implications on conditions that financial firms must focus on in order to secure competitiveness.