bluuebunny/crossref_metadata_2025 huggingface dataset:
A new perspective and comparative study on demixing and gelation behavior of cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate ternary solutions
Authors: Okhovat Ahmad , Karimi Mohammad , Zokaee Ashtiani Farzin
Published: July 2017

Cellulose acetate (CA), cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB) were fabricated as membrane via nonsolvent induced phase separation process. N,N‐Dimethylformamide (DMF) and N,N‐Dimethylacetamide (DMAc) as solvents and water as nonsolvent were employed. Ternary phase diagrams for all six ternary systems were constructed using Flory‐Huggins theory. In this way, cloud points as well as Berghman's points were determined. Modulus of polymers steepened in various concentration of solvent/nonsolvent mixtures were measured to find the weight fraction of polymer (wp) in which vitrification takes place. WP values for CA, CAP, and CAB were obtained 0.59, 0.67, and 0.74 in presence of DMF while those were 0.69, 0.74, and 0.84 in presence of DMAc; whereas glass transition temperatures (Tg) for three polymers were determined 180°C, 142°C, and 101°C correspondingly. Pure water flux for CA, CAP, and CAB membrane increased from 75.7 to 83.4 and 290.3 and from 109.6 to 116.1 and 400.3 L/m2 h bar when DMF and DMAc were used as solvents, respectively. Results revealed that as Tg of polymer decreases, the membrane structure vitrifies at higher polymer concentration with more porous structure, bigger pores, higher permeate flux followed by decrease in mechanical strength. POLYM. ENG. SCI., 58:1135–1145, 2018. © 2017 Society of Plastics Engineers
Studying the formation mechanism ofin situpoly(butylene terephthalate) microfibrils prepared by one‐step direct extrusion via orthogonal experimental design
Authors: Huang Ying , He Yadong , Wang Yangye , Huang Qiangqiang , Xin Chunling
Published: July 2017

Polypropylene/poly(butylene terephthalate) (PP/PBT) microfibrillar composites (MFCs) were prepared throughin situone‐step direct extrusion using a triangle‐arrayed triple‐screw extruder (TTSE) at a processing temperature between the melting points of two components. The orthogonal experimental method was designed to assess the effects of the PBT content and processing parameters (temperature, screw speed, and feed rate) on the morphology of PBT fibrils. It can be found that the most important influence factor on the fibril formation is the PBT content, followed by temperature, feed rate, and screw speed. Furthermore, the morphological evolution procedures of the dispersed phase started from spherical pellets to ellipsoids or ribbons, forming short fibrils, and consequently high‐aspect‐ratio fibrils appeared under the alternating shear‐extensional flow field. Moreover, the rheological properties of linear PP incorporating fibrillated PBT were thoroughly investigated. The relaxation time of blends with various fibrous PBT was linearly proportional to the aspect ratio of fibrils. Strain‐hardening in extensional flow was observed for blends with long fibrils, and the strain‐hardening factor grew with the fibrillar aspect ratio, indicating the formation of a physical entanglement network between fibrils and matrix. POLYM. ENG. SCI., 58:1166–1173, 2018. © 2017 Society of Plastics Engineers
One‐pot approach synthesizing and characterization of random copolymerization of ethyl acrylate‐co‐methyl methacrylate with broad range of glass transition temperature onto collagen
Authors: Bazrafshan Zahra , Stylios George K.
Published: July 2017

Collagen is a natural polymer that cannot be applied freely to specific end uses due to its inherent drawbacks. Grafting polymerization of methyl methacrylate‐co‐ethyl acrylate was applied to modify the surface of acid soluble collagen (ASC). The main objective of this work is not only reducing the hydrophilic behavior of collagen on which has been concentrated so far but also successfully showed that the introduced co‐monomers onto ASC can alter the thermal behavior of the resulted copolymer. The level of branched copolymer significantly influenced the initial viscosity in studied co‐monomer feed ratios. The graft polymerization of collagen demonstrated the meaningful change in conductivity value of branched copolymer, where the copolymer in side chain with low dielectric constant covalently bonded onto the ASC. The increase in the co‐monomer feed ratio had no significant effect on conductivity value of copolymer, afterwards. The novelty of this work was determined to achieve the new copolymer onto the backbone of collagen to be used in specific thermally stabled end uses that the sufficient chain entanglements improve the flexibility of final product. POLYM. ENG. SCI., 58:1261–1267, 2018. © 2017 Society of Plastics Engineers
Relationships between Medication Adherence and Cardiovascular Disease Risk Factor Control in Elderly Patients with Diabetes
Authors: Raebel Marsha A. , Dyer Wendy , Nichols Gregory A. , Goodrich Glenn K. , Schmittdiel Julie A.
Published: July 2017

Background

The Centers for Medicare and Medicaid Services (CMS) Medicare Star program provides incentives to health plans when their patients with diabetes meet adherence targets to angiotensin‐converting enzyme inhibitors/angiotensin II receptor blockers (ACEIs/ARBs) and statins. While a link between adherence and cardiovascular risk factor control is established, most studies included young patients with few comorbidities. Whether the Star adherence target is associated with reduced blood pressure or low‐density lipoprotein cholesterol (LDL‐C) in complex older patients is not well understood.

Objectives

Determine correlates of adherence and examine the effect of meeting Star adherence targets on blood pressure and LDL‐C in the Medicare‐aged diabetes population.

Design and Subjects

Retrospective cohort study of 129,040 patients with diabetes aged 65 or older.

Measures

Adherence estimated using proportion of days covered target ≥ 0.8; blood pressure < 140/90 mg Hg; LDL‐C < 100 mg/dl. Modified Poisson regression used to assess relationships.

Results

Adherence differed little across elderly age groups. Compared to no comorbidity, high comorbidity (≥ 4) was associated with lower ACEI/ARB (risk ratio [RR] 0.88 [95% confidence interval (CI) 0.87–0.89]) or statin (RR 0.91 [0.90–0.92]) adherence. ACEI/ARB adherence was not associated with blood pressure < 140/90 mm Hg in patients ≥ 85 years (RR 1.01 [0.96–1.07]) or with multiple comorbidities (e.g., 3: RR 1.04 [0.99–1.08]). Statin adherence and LDL‐C < 100 mg/dl were associated in all elderly age groups (e.g., ≥ 85: RR 1.13 [1.09–1.16]) and comorbidity levels (e.g., ≥ 4: RR 1.13 [1.12–1.15]).

Conclusions

Adherence to ACEI/ARB is not linked with reduced blood pressure in patients with diabetes who are at least 85 years or with multiple comorbidities.
The impact of multifocal perineural invasion on biochemical recurrence and timing of adjuvant androgen‐deprivation therapy in high‐risk prostate cancer following radical prostatectomy
Authors: Sun Guangxi , Huang Rui , Zhang Xingming , Shen Pengfei , Gong Jing , Zhao Jinge , Liu Jiandong , Tang Qidun , Shu Kunpeng , Yin Xiaoxue , Chen Ni , Zeng Hao
Published: July 2017

Background: Perineural invasion (PNI) is a distinct pathologic entity and a recognized source of tumor spread. However, the role of PNI in high‐risk prostate cancer (PCa) has not been explored. The aims of the study were to investigate the impact of PNI on biochemical recurrence (BCR) and optimal timing of adjuvant androgen‐deprivation therapy (ADT) after radical prostatectomy (RP).

Methods: A total of 265 prostatectomies, median follow‐up 45 months, were assessed for the presence and intensity of PNI (unifocal and multifocal) in RP specimens. Kaplan‐Meier curves were used to estimate BCR probabilities. Cox proportional hazard models were used to address predictors of BCR. Harrell's C‐index was conducted to further validate prognostic value of multi‐PNI.

Results: A total of 123 patients (46.4%) were PNI positive, among which, 91 (74%) and 32 (26%) had unifocal PNI (uni‐PNI) and multifocal PNI (multi‐PNI), respectively. The presence of multi‐PNI was strongly associated with increasing incidence of BCR (HR = 3.87, 95%CI: 1.66‐9.01, P = 0.002). Patients with uni‐PNI had a similar BCR rate to those without PNI after adjuvant ADT. For men with multi‐PNI, immediate ADT was superior to delayed ADT in decreasing biochemical failure.

Conclusions: Our findings suggest that detection of multi‐PNI in high‐risk RP specimens could be a prognosticator for early biochemical relapse post‐surgery. Initiation of adjuvant therapy may be appropriate in patients with multi‐PNI as soon as possible after surgery.
An environmental pollutant, 9,10‐phenanthrenequinone, activates human TRPA1 via critical cysteines 621 and 665
Authors: Muraki Katsuhiko , Sekine Takashi , Ando Yuna , Suzuki Hiroka , Hatano Noriyuki , Hirata Tadashi , Muraki Yukiko
Published: July 2017

Transient receptor potential ankyrin 1 (TRPA1) is activated by noxious cold, mechanical stimulation, and irritant chemicals. In our recent study, 9, 10‐phenanthrenequinone (9,10‐PQ) is the most potent irritant for activation of NRF2 among 1395 cigarette smoke components and it may be, therefore, important to find its additional targets. Here, we show that 9,10‐PQ functions as an activator of TRPA1 in human embryonic kidney (HEK) cells expressing human wild‐type TRPA1 (HEK‐wTRPA1) and human alveolar A549 (A549) cells. Application of 9,10‐PQ at 0.1–10 μmol/L induced a concentration‐dependent Ca2+ response as well as inward currents at −50 mV in HEK‐wTRPA1 cells. The current response was blocked by TRPA1 antagonists, HC‐030031 (HC) and A‐967079. To test whether 9,10‐PQ affects the cysteine residues of TRPA1, we expressed mutant TRPA1 channels in HEK cells (HEK‐muTRPA1) in which six different cysteine residues were replaced with serine. Among them, a mutation of cysteine 621 (C621S) abolished the 9,10‐PQ‐induced Ca2+ and current responses. The channel activity induced by 9,10‐PQ was also abolished in excised inside‐out patches isolated from HEK‐muTRPA1 cells with the C621S substitution. Although a mutation of cysteine 665 (C665S) reduced the 9,10‐PQ‐induced response, channel sensitization by pretreatment with Cu2+ plus 1,10‐phenanthroline and by internal dialysis of 3 μmol/L Ca2+ restored the response. However, a double mutant with C621S and C665S substitutions had little response to 9,10‐PQ, even when sensitized by Ca2+ dialysis. In A549 cells, 9,10‐PQ induced an HC‐sensitive Ca2+ response. Our findings demonstrate that 9,10‐PQ activation of human TRA1 is dependent on cysteine residues 621 and 665.
Thin film solar cells of cubic structured SnS‐SnSe
Authors: Barrios‐Salgado Enue , Rodríguez‐Guadarrama Luis Alberto , Ramón García María Luisa , Martínez Laura Guerrero , Nair M. T. S. , Nair P. K.
Published: July 2017

Thin films of tin sulfide and tin selenide with a large simple cubic (CUB) crystalline structure with lattice constants of 11.5873 Å (SnS‐CUB) and 11.9632 Å (SnSe‐CUB) were prepared via chemical deposition and integrated into solar cell structures. Heating of SnS‐SnSe‐CUB layers permitted control of their optical bandgap in the interval of 1.38 eV (SnSe‐CUB) and 1.7 eV (SnS‐CUB). Such layers have p‐type electrical conductivity 10−3–10−2 Ω−1 cm−1 compared with 10−6 Ω−1 cm−1 of SnS‐CUB. Solar cells were fabricated on fluorine‐doped tin oxide (FTO) glass. Thin films of CdS (80 nm), Sb2S3 (30–60 nm), or Sb2(S‐Se)3 (60 nm) were prepared on FTO by chemical deposition. The best results on solar cells were recorded for FTO/CdS/Sb2S3 (60 nm)/SnS‐Se‐CUB (180 nm)/C‐Ag with open circuit voltage of 496 mV; short circuit current density of 7.5 mA cm−2; and conversion efficiency of 1.15%, measured under solar radiation intensity of 1000 W m−2 in cell area of 0.5 cm2.
High‐temperature fabrication of Ag(In,Ga)Se2 thin films for applications in solar cells
Authors: Zhang Xianfeng , Yamada Akira , Kobayashi Masakazu
Published: July 2017

Molecular beam epitaxy was used to fabricate Ag(In,Ga)Se2 (AIGS) thin films. To improve the diffusion of Ag, high‐temperature deposition and high‐temperature annealing methods were applied to fabricate AIGS films. The as‐grown AIGS thin films were then used to make AIGS solar cells. We found that grain size and crystallinity of AIGS films were considerably improved by increasing the deposition and annealing temperature. For high‐temperature deposition, temperatures over 600 °C led to decomposition of the AIGS film, desorption of In, and deterioration of its crystallinity. The most appropriate deposition temperature was 590 °C and a solar cell with a power conversion efficiency of 4.1% was obtained. High‐temperature annealing of the AIGS thin films showed improved crystallinity as annealing temperature was increased and film decomposition and In desorption were prevented. A solar cell based on this film showed the highest conversion efficiency of 6.4% when annealed at 600 °C. When the annealing temperature was further increased to 610 °C, the performance of the cell deteriorated due to loss of the out‐of‐plane Ga gradient.
Scatterometer estimates of the tropical sea‐breeze circulation near Darwin, with comparison to regional models
Authors: Brown Andrew L. , Vincent Claire L. , Lane Todd P. , Short Ewan , Nguyen Hanh
Published: July 2017

In tropical coastal environments, simulating the diurnal cycle of wind and precipitation in numerical weather and climate models presents unique challenges due to the interaction of intraseasonal and mesoscale dynamics. This can lead not only to incorrect short‐term weather forecasts but also to unphysical energy and momentum transport by convective processes. In particular, the sea/land‐breeze circulation and its role in initiating convection has been identified as a possible source of errors in the timing and offshore extent of coastal precipitation in the Tropics.

In this study, the offshore land/sea breeze around Darwin, Australia, is examined using scatterometer wind observations and two regional atmospheric models. Although the comparison is limited by satellite swath times which cluster around two times of day, useful results are obtained by sub‐sampling the simulated data to match the coverage of the scatterometer data.

We find that offshore surface sea‐breeze characteristics (intensity and horizontal spatial extent) from the models and satellite estimates are generally in good agreement, with intensity differences less than 2 m s−1, and offshore extents not varying by more than approximately 150 km. The variation in offshore extent and amplitude of the land/sea‐breeze wind perturbations with monsoon regime is well simulated. Furthermore, despite the simplifying assumptions of linear sea‐breeze theory, the model and scatterometer results are in broad agreement with theoretical values, particularly in the presence of the weak background winds during the monsoon break period.
Introducing a globally consistent orbital‐based localization system
Authors: Boukas Evangelos , Gasteratos Antonios , Visentin Gianfranco
Published: July 2017

In spite of the good performance of space exploratory missions, open issues still await to be solved. In autonomous or composite semi‐autonomous exploration of planetary land surfaces, rover localization is such an issue. The rovers of these missions (e.g., the MER and MSL) navigate relatively to their landing spot, ignoring their exact position on the coordinate system defined for the celestial body they explore. However, future advanced missions, like the Mars Sample Return, will require the localization of rovers on a global frame rather than the arbitrarily defined landing frame. In this paper we attempt to retrieve the absolute rover's location by identifying matching Regions of Interest (ROIs) between orbital and land images. In particular, we propose a system comprising two parts, an offline and an onboard one, which functions as follows: in advance of the mission a Global ROI Network (GN) is built offline by investigating the satellite images near the predicted touchdown ellipse, while during the mission a Local ROI Network (LN) is constructed counting on the images acquired by the vision system of the rover along its traverse. The last procedure relies on the accurate VO‐based relative rover localization. The LN is then paired with the GN through a modified 2D DARCES algorithm. The system has been assessed on real data collected by the ESA at the Atacama desert. The results demonstrate the system's potential to perform absolute localization, on condition that the area includes discriminative ROIs. The main contribution of this work is the enablement of global localization performed on contemporary rovers without requiring any additional hardware, such as long range LIDARs.
Metal Organic Frameworks: A New Generation Coordination Polymers for Visible Light Photocatalysis
Authors: Kuila Aneek , Surib Nur A. , Mishra Nirmalendu S. , Nawaz Ahmad , Leong Kah H. , Sim Lan C. , Saravanan Pichiah , Ibrahim Shaliza
Published: July 2017

The twin associates, pollution and energy are the bottleneck for the sustainable development of present and future. Visible light driven nanomaterials have emerged as sustainable and eco‐friendly outlook to address these burning issues. Metal‐organic frameworks [MOFs] that was widely considered for gas storage and separations, notably for hydrogen have overlooked the conventional light driven nanomaterials owing to their excellence in materials characteristics; enormous surface area, analogous reactive sites and tuneable functionality. They soared slowly and gained interest as visible light photo catalyst, for driving the photocatalysis and can perform versatile reactions like elimination of aquatic organics, general organic synthesis, water split for hydrogen production, CO2 reduction and etc. Owing to their demand, we articulated the present review on MOFs as light driven nanomaterial that comprises of its evolution, synthesis, structure, functionality, application, and its future.
Metal‐Free Catalyst‐Controlled Chemoselective Synthesis of Aryl α‐Ketoesters and Primary α‐Ketoamides from Aryl Acetimidates
Authors: Kumar Yogesh , Jaiswal Yogesh , Shaw Mukta , Kumar Amit
Published: July 2017

A simple and chemoselective method has been developed for the divergent synthesis of aryl α‐ketoesters and primary α‐ketoamides from pre‐functionalized arylacetimidates under metal‐free conditions. The chemoselective outcome is controlled by the subtle catalyst. This methodology features operational simplicity with broad substrate scope, metal‐free catalyst, and usage of easy to handle reagents. Based on a series of control experiments, a plausible reaction mechanism is also proposed.
Genome‐wide map of Apn1 binding sites under oxidative stress in Saccharomyces cerevisiae
Authors: Morris Lydia P. , Conley Andrew B. , Degtyareva Natalya , Jordan I. King , Doetsch Paul W.
Published: July 2017

The DNA is cells is continuously exposed to reactive oxygen species resulting in toxic and mutagenic DNA damage. Although the repair of oxidative DNA damage occurs primarily through the base excision repair (BER) pathway, the nucleotide excision repair (NER) pathway processes some of the same lesions. In addition, damage tolerance mechanisms, such as recombination and translesion synthesis, enable cells to tolerate oxidative DNA damage, especially when BER and NER capacities are exceeded. Thus, disruption of BER alone or disruption of BER and NER in Saccharomyces cerevisiae leads to increased mutations as well as large‐scale genomic rearrangements. Previous studies demonstrated that a particular region of chromosome II is susceptible to chronic oxidative stress‐induced chromosomal rearrangements, suggesting the existence of DNA damage and/or DNA repair hotspots. Here we investigated the relationship between oxidative damage and genomic instability utilizing chromatin immunoprecipitation combined with DNA microarray technology to profile DNA repair sites along yeast chromosomes under different oxidative stress conditions. We targeted the major yeast AP endonuclease Apn1 as a representative BER protein. Our results indicate that Apn1 target sequences are enriched for cytosine and guanine nucleotides. We predict that BER protects these sites in the genome because guanines and cytosines are thought to be especially susceptible to oxidative attack, thereby preventing large‐scale genome destabilization from chronic accumulation of DNA damage. Information from our studies should provide insight into how regional deployment of oxidative DNA damage management systems along chromosomes protects against large‐scale rearrangements. Copyright © 2017 John Wiley & Sons, Ltd.
Two‐way Interaction Effects of Perioperative Complications on 30‐Day Mortality in General Surgery
Authors: Kim Minjae , Li Guohua
Published: July 2017

Background

Multiple perioperative complications increase mortality risk, and certain complications synergistically increase this risk to a greater degree than might be expected if the complications were independent, but these effects are not well established.

Methods

This is a retrospective cohort study of 422,827 intraabdominal general surgery patients (American College of Surgeons National Surgical Quality Improvement Program 2005–2011). Eight complications were evaluated: acute respiratory failure (ARF), acute kidney injury (AKI), sepsis/septic shock, stroke, cardiac arrest (CA), myocardial infarction (MI), deep vein thrombosis/pulmonary embolus, and transfusion. Each combination of two complications (28 total) was modeled using a Cox model for 30‐day mortality, with adjustment for preoperative comorbidities and risk factors. Additive interaction was determined with the relative excess risk due to interaction (RERI). A positive RERI indicates that the mortality risk with both complications is greater than the sum of the individual mortality risks. Bonferroni correction was applied (α= 0.05/28 = 0.0018).

Results

Seven combinations demonstrated positive interaction: sepsis‐CA (RERI 88.1;p< 0.0001), ARF–AKI (RERI 50.5;p< 0.0001), AKI–sepsis (RERI 33.9;p< 0.0001), sepsis–stroke (RERI 33.9;p< 0.0001), ARF–stroke (RERI 32.3;p< 0.0001), AKI–MI (RERI 24.5;p= 0.0013), and ARF–sepsis (RERI 19.2;p< 0.0001). Two combinations demonstrated negative interaction: ARF–CA (RERI −65.1;p= 0.0017) and CA‐transfusion (RERI −52.0,p< 0.0001).

Conclusions

Interaction effects exist between certain complications to increase the risk of short‐term mortality. ARF, AKI, sepsis, and stroke were most likely to be involved in positive interactions. Further research into the mechanisms for these effects will be necessary to develop strategies to minimize the compounding effects of multiple complications in the perioperative period.
An introduction to computational tools for differential binding analysis with ChIP‐seq data
Authors: Tu Shiqi , Shao Zhen
Published: July 2017

Background

Gene transcription in eukaryotic cells is collectively controlled by a large panel of chromatin associated proteins and ChIP‐seq is now widely used to locate their binding sites along the whole genome. Inferring the differential binding sites of these proteins between biological conditions by comparing the corresponding ChIP‐seq samples is of general interest, yet it is still a computationally challenging task.

Results

Here, we briefly review the computational tools developed in recent years for differential binding analysis with ChIP‐seq data. The methods are extensively classified by their strategy of statistical modeling and scope of application. Finally, a decision tree is presented for choosing proper tools based on the specific dataset.

Conclusions

Computational tools for differential binding analysis with ChIP‐seq data vary significantly with respect to their applicability and performance. This review can serve as a practical guide for readers to select appropriate tools for their own datasets.
Multifaceted roles of complementary sequences on circRNA formation
Authors: Yang Qin , Wang Ying , Yang Li
Published: July 2017

Background

Circular RNAs (circRNAs) from back‐spliced exon(s) are characterized by the covalently closed loop feature with neither 5′ to 3′ polarity nor polyadenylated tail. By using specific computational approaches that identify reads mapped to back‐splice junctions with a reversed genomic orientation, ten thousands of circRNAs have been recently re‐identified in various cell lines/tissues and across different species. Increasing lines of evidence suggest that back‐splicing is catalyzed by the canonical spliceosomal machinery and modulated by cis‐elements and trans‐factors.

Results

In this mini‐review, we discuss our current understanding of circRNA biogenesis regulation, mainly focusing on the complex regulation of complementary sequences, especially Alus in human, on circRNA formation.

Conclusions

Back‐splicing can be significantly facilitated by RNA pair formed by orientation‐opposite complementary sequences that juxtapose flanking introns of circularized exon(s). RNA pair formed within individual introns competes with RNA pair formed across flanking introns in the same gene locus, leading to distinct choices for either canonical splicing or back‐splicing. Multiple RNA pairs that bracket different circle‐forming exons compete for alternative back‐splicing selection, resulting in multiple circRNAs generated in a single gene locus.
A Historical Review of Gender-Affirming Medicine: Focus on Genital Reconstruction Surgery
Authors: Frey Jordan D. , Poudrier Grace , Thomson Jennifer E. , Hazen Alexes
Published: July 2017

Gender dysphoria (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) is characterized by a marked discrepancy between one’s birth-assigned sex and one’s gender identity and is sometimes addressed by gender-affirming surgery. As public visibility and institutional support for the transgender and gender non-conforming population continue to increase, the demand for competent multidisciplinary teams of medical professionals equipped to care for this population is expected to rise—including plastic surgeons, urologists, gynecologists, endocrinologists, and breast surgeons, among others. Genital reconstruction procedures for the male-to-female and female-to-male transgender patient present unique surgical challenges that continue to evolve from their respective origins in the 19th and 20th centuries. A historical review of surgical techniques and standards of care attendant to gender-affirming medicine is presented, with foremost emphasis placed on how techniques for genital reconstruction in particular continue to evolve and advance. In addition, the current status of transition-related health care in the United States, including research gaps and contemporary clinical challenges, is reviewed.
Magnitude rather than number: More evidence needed
Authors: Hyde Daniel C. , Mou Yi
Published: July 2017

Leibovich et al. do not present enough empirical support to overturn decades of work supporting a number sense nor to convince the reader that a magnitude sense provides a better explanation of the literature. Here we highlight what we feel are the main points of weakness and the types of evidence that could be provided to be more convincing.
Magnitude, numerosity, and development of number: Implications for mathematics disabilities
Authors: Jordan Nancy C. , Rinne Luke , Resnick Ilyse M.
Published: July 2017

Leibovich et al. challenge the prevailing view that non-symbolic number sense (e.g., sensing number the same way one might sense color) is innate, that detection of numerosity is distinct from detection of continuous magnitude. In the present commentary, the authors' viewpoint is discussed in light of the integrative theory of numerical development along with implications for understanding mathematics disabilities.
What is the precise role of cognitive control in the development of a sense of number?
Authors: Merkley Rebecca , Scerif Gaia , Ansari Daniel
Published: July 2017

The theory put forward by Leibovich et al. of how children acquire a sense of number does not specify the mechanisms through which cognitive control plays a role in this process. We argue that visual attention and number word knowledge influence each other over development and contribute to the development of the concept of number.
The contributions of non-numeric dimensions to number encoding, representations, and decision-making factors
Authors: Odic Darko
Published: July 2017

Leibovich et al. suggest that congruency effects in number perception (biases towards smaller, denser, etc., dots) are evidence for the number's dependence on these dimensions. I argue that they fail to differentiate between effects at three distinct levels of number perception – encoding, representations, and decision making – and that differentiating between these allows the number to be independent from, but correlated with, non-numeric dimensions.
Population genetic structure and gene flow of Adélie penguins (Pygoscelis adeliae) breeding throughout the western Antarctic Peninsula
Authors: Gorman Kristen B. , Talbot Sandra L. , Sonsthagen Sarah A. , Sage George K. , Gravely Meg C. , Fraser William R. , Williams Tony D.
Published: July 2017

Adélie penguins (Pygoscelis adeliae) are responding to ocean–climate variability throughout the marine ecosystem of the western Antarctic Peninsula (WAP) where some breeding colonies have declined by 80%. Nuclear and mitochondrial DNA (mtDNA) markers were used to understand historical population genetic structure and gene flow given relatively recent and continuing reductions in sea ice habitats and changes in numbers of breeding adults at colonies throughout the WAP. Genetic diversity, spatial genetic structure, genetic signatures of fluctuations in population demography and gene flow were assessed in four regional Adélie penguin colonies. The analyses indicated little genetic structure overall based on bi-parentally inherited microsatellite markers (FST=-0.006–0.004). No significant variance was observed in overall haplotype frequency (mtDNAΦST=0.017;P=0.112). Some comparisons with Charcot Island were significant, suggestive of female-biased philopatry. Estimates of gene flow based on a two-population coalescent model were asymmetrical from the species’ regional core to its northern range. Breeding Adélie penguins of the WAP are a panmictic population and hold adequate genetic diversity and dispersal capacity to be resilient to environmental change.
Destruction of Be star disk by large scale magnetic fields
Authors: ud-Doula Asif , Owocki Stanley , Kee Nathaniel (Dylan) , Vanyo Michael
Published: July 2017

Classical Be stars are rapidly rotating stars with circumstellar disks that come and go on time scale of years. Recent observational data strongly suggests that these stars lack the 10% incidence of global magnetic fields observed in other main-sequence B stars. Such an apparent lack of magnetic fields may indicate that Be disks are fundamentally incompatible with a significant large scale magnetic field. In this work, using numerical magnetohydrodynamics (MHD) simulations, we show that a dipole field of only 100G can lead to the quick disruption of a Be disk. Such a limit is in line with the observational upper limits for these objects.
Wind-embedded shocks in FASTWIND: X-ray emission and K-shell absorption
Authors: Carneiro L. P. , Puls J. , Sundqvist J. O. , Hoffmann T. L.
Published: July 2017

EUV and X-ray radiation emitted from wind-embedded shocks can affect the ionization balance in the outer atmospheres of massive stars, and can also be the mechanism responsible for producing highly ionized atoms detected in the wind UV spectra. To investigate these processes, we implemented the emission from wind-embedded shocks and related physics into our atmosphere/spectrum synthesis code FASTWIND. We also account for the high energy absorption of the cool wind, by adding important K-shell opacities. Various tests justfying our approach have been described by Carneiro+(2016, A&A 590, A88).

In particular, we studied the impact of X-ray emission on the ionization balance of important elements. In almost all the cases, the lower ionization stages (O iv, N iv, P v) are depleted and the higher stages (N v, O v, O vi) become enhanced. Moreover, also He lines (in particular He ii 1640 and He ii 4686) can be affected as well.

Finally, we carried out an extensive discussion of the high-energy mass absorption coefficient, κν, regarding its spatial variation and dependence on Teff. We found that (i) the approximation of a radially constant κν can be justified for r ⩾ 1.2R* and λ ⩽ 18 Å, and also for many models at longer wavelengths. (ii) In order to estimate the actual value of this quantity, however, the He ii background needs to be considered from detailed modeling.
Mass of dust in core-collapse supernovae as viewed from energy balance in the ejecta
Authors: Nozawa Takaya
Published: July 2017

Recent far-infrared (FIR) observations have revealed the presence of freshly formed dust with the masses exceeding 0.1 M⊙ in young remnants of core-collapse supernovae (CCSNe) such as SN 1987A and Cassiopeia A. Meanwhile, dust masses derived from near- to mid-infrared (N/MIR) observations of CCSNe a few years after explosions are on the order of 10−5–10−3M⊙. Here, we demonstrate that such small dust masses as seen from N/MIR observations would not necessarily reflect the formation history of dust but could be just limited by the luminosity of the SN that can heat up dust formed in the ejecta.
Searching for self-enrichment in Cygnus OB2
Authors: Berlanas Sara R. , Herrero Artemio , Comerón Fernando , Pasquali Anna , Simón-Díaz Sergio
Published: July 2017

Cygnus OB2 is a rich and relatively close (d~1.4 kpc) OB association in our Galaxy. It represents an ideal testbed for our theories about self-enrichment processes produced by pollution of the interstellar medium by successive generations of massive stars. Comerón & Pasquali (2012, A&A, 543, A101) found a correlation between the age of young stellar groups in Cygnus OB2 and their Galactic longitude. If is associated with a chemical composition gradient, it could support these self-enrichment processes.
A new sample of red supergiants in the Inner Galaxy
Authors: Messineo M. , Zhu Q. , Figer D. F. , Menten K. M. , Ivanov V. D. , Kudritzki R.-P. , Chen C.-H. Rosie
Published: July 2017

We carried out a pivot experiment to select distant luminous late-type stars on the basis on their 2MASS and GLIMPSE photometry. Low-resolution infrared spectra enabled us to measure the equivalent widths (EWs) of their CO band-heads at 2.293 μm, and to confirm an extraordinarily high detection rate of red supergiants (RSGs), i.e. 61% (Messineo et al. (2016)).
Taking the Measure of Massive Stars and their Environments with the CHARA Array Long-baseline Interferometer
Authors: Gies Douglas R.
Published: July 2017

Most massive stars are so distant that their angular diameters are too small for direct resolution. However, the observational situation is now much more favorable, thanks to new opportunities available with optical/IR long-baseline interferometry. The Georgia State University Center for High Angular Resolution Astronomy Array at Mount Wilson Observatory is a six-telescope instrument with a maximum baseline of 330 meters, which is capable of resolving stellar disks with diameters as small as 0.2 milliarcsec. The distant stars are no longer out of range, and many kinds of investigations are possible. Here we summarize a number of studies involving angular diameter measurements and effective temperature estimates for OB stars, binary and multiple stars (including the σ Orionis system), and outflows in Luminous Blue Variables. An enlarged visitors program will begin in 2017 that will open many opportunities for new programs in high angular resolution astronomy.
There Are (super)Giants in the Sky: Searching for Misidentified Massive Stars in Algorithmically-Selected Quasar Catalogs
Authors: Dorn-Wallenstein Trevor Z. , Levesque Emily
Published: July 2017

Thanks to incredible advances in instrumentation, surveys like the Sloan Digital Sky Survey have been able to find and catalog billions of objects, ranging from local M dwarfs to distant quasars. Machine learning algorithms have greatly aided in the effort to classify these objects; however, there are regimes where these algorithms fail, where interesting oddities may be found. We present here an X-ray bright quasar misidentified as a red supergiant/X-ray binary, and a subsequent search of the SDSS quasar catalog for X-ray bright stars misidentified as quasars.
Stellar Winds in Massive X-ray Binaries
Authors: Kretschmar Peter , Martínez-Núñez Silvia , Bozzo Enrico , Oskinova Lidia M. , Puls Joachim , Sidoli Lara , Sundqvist Jon Olof , Blay Pere , Falanga Maurizio , Fürst Felix , Gímenez-García Angel , Kreykenbohm Ingo , Kühnel Matthias , Sander Andreas , Torrejón José Miguel , Wilms Jörn , Podsiadlowski Philipp , Manousakis Antonios
Published: July 2017

Strong winds from massive stars are a topic of interest to a wide range of astrophysical fields. In High-Mass X-ray Binaries the presence of an accreting compact object on the one side allows to infer wind parameters from studies of the varying properties of the emitted X-rays; but on the other side the accretor’s gravity and ionizing radiation can strongly influence the wind flow. Based on a collaborative effort of astronomers both from the stellar wind and the X-ray community, this presentation attempts to review our current state of knowledge and indicate avenues for future progress.
Observational signatures of hot-star magnetospheres
Authors: Oksala Mary E.
Published: July 2017

Magnetic fields play an important role in shaping the circumstellar environment of hot, massive stars. Observational diagnostics give clues to the presence of magnetism across the entire electromagnetic spectrum. Infrared features can show more complex structure, indicating they may probe deeper opacities than optical features. Optical and infrared features mimic each other, with identical blue and red peak variations and identical peak velocity of material. These comparisons indicate the location of the infrared and optical emitting material is similar. Longer wavelength diagnostics are currently being developed and tested. IR spectroscopy is a viable tool to detect magnetic candidates in the Galactic center and star forming regions.
The Tarantula Nebula as a template for extragalactic star forming regions from VLT/MUSE and HST/STIS
Authors: Crowther Paul A. , Caballero-Nieves Saida M. , Castro Norberto , Evans Christopher J.
Published: July 2017

We present VLT/MUSE observations of NGC 2070, the dominant ionizing nebula of 30 Doradus in the LMC, plus HST/STIS spectroscopy of its central star cluster R136. Integral Field Spectroscopy (MUSE) and pseudo IFS (STIS) together provides a complete census of all massive stars within the central 30×30 parsec2 of the Tarantula. We discuss the integrated far-UV spectrum of R136, of particular interest for UV studies of young extragalactic star clusters. Strong He iiλ1640 emission at very early ages (1–2 Myr) from very massive stars cannot be reproduced by current population synthesis models, even those incorporating binary evolution and very massive stars. A nebular analysis of the integrated MUSE dataset implies an age of ~4.5 Myr for NGC 2070. Wolf-Rayet features provide alternative age diagnostics, with the primary contribution to the integrated Wolf-Rayet bumps arising from R140 rather than the more numerous H-rich WN stars in R136. Caution should be used when interpreting spatially extended observations of extragalactic star-forming regions.
Massive stars in advanced evolutionary stages, and the progenitor of GW150914
Authors: Hamann Wolf-Rainer , Oskinova Lidia , Todt Helge , Sander Andreas , Hainich Rainer , Shenar Tomer , Ramachandran Varsha
Published: July 2017

The recent discovery of a gravitational wave from the merging of two black holes of about 30 solar masses each challenges our incomplete understanding of massive stars and their evolution. Critical ingredients comprise mass-loss, rotation, magnetic fields, internal mixing, and mass transfer in close binary systems. The imperfect knowledge of these factors implies large uncertainties for models of stellar populations and their feedback. In this contribution we summarize our empirical studies of Wolf-Rayet populations at different metallicities by means of modern non-LTE stellar atmosphere models, and confront these results with the predictions of stellar evolution models. At the metallicity of our Galaxy, stellar winds are probably too strong to leave remnant masses as high as ~30 M⊙, but given the still poor agreement between evolutionary tracks and observation even this conclusion is debatable. At the low metallicity of the Small Magellanic Cloud, all WN stars which are (at least now) single are consistent with evolving quasi-homogeneously. O and B-type stars, in contrast, seem to comply with standard evolutionary models without strong internal mixing. Close binaries which avoided early merging could evolve quasi-homogeneously and lead to close compact remnants of relatively high masses that merge within a Hubble time.
The circumstellar environments of B[e] Supergiants
Authors: Maravelias G. , Kraus M. , Cidale L. , Arias M. L. , Aret A. , Fernandes M. Borges
Published: July 2017

The evolution of massive stars encompasses short-lived transition phases in which mass-loss is more enhanced and usually eruptive. A complex environment, combining atomic, molecular and dust regions, is formed around these stars. In particular, the circumstellar environment of B[e] Supergiants is not well understood. To address that, we have initiated a campaign to investigate their environments for a sample of Galactic and Magellanic Cloud sources. Using high-resolution optical and near-infrared spectra (MPG-ESO/FEROS, GEMINI/Phoenix and VLT/CRIRES, respectively), we examine a set of emission features ([OI], [CaII], CO bandheads) to trace the physical conditions and kinematics in their formation regions. We find that the B[e] Supergiants are surrounded by a series of rings of different temperatures and densities, a probable result of previous mass-loss events. In many cases the CO forms very close to the star, while we notice also an alternate mixing of densities and temperatures (which give rise to the different emission features) along the equatorial plane.
The wind-wind collision hole in eta Car
Authors: Damineli A. , Teodoro M. , Richardson N. D. , Gull T. R. , Corcoran M. F. , Hamaguchi K. , Groh J. H. , Weigelt G. , Hillier D. J. , Russell C. , Moffat A. , Pollard K. R. , Madura T. I.
Published: July 2017

Eta Carinae is one of the most massive observable binaries. Yet determination of its orbital and physical parameters is hampered by obscuring winds. However the effects of the strong, colliding winds changes with phase due to the high orbital eccentricity. We wanted to improve measures of the orbital parameters and to determine the mechanisms that produce the relatively brief, phase-locked minimum as detected throughout the electromagnetic spectrum. We conducted intense monitoring of the He ii λ4686 line in η Carinae for 10 months in the year 2014, gathering ~300 high S/N spectra with ground- and space-based telescopes. We also used published spectra at the FOS4 SE polar region of the Homunculus, which views the minimum from a different direction. We used a model in which the He ii λ4686 emission is produced by two mechanisms: a) one linked to the intensity of the wind-wind collision which occurs along the whole orbit and is proportional to the inverse square of the separation between the companion stars; and b) the other produced by the ‘bore hole’ effect which occurs at phases across the periastron passage. The opacity (computed from 3D SPH simulations) as convolved with the emission reproduces the behavior of equivalent widths both for direct and reflected light. Our main results are: a) a demonstration that the He ii λ4686 light curve is exquisitely repeatable from cycle to cycle, contrary to previous claims for large changes; b) an accurate determination of the longitude of periastron, indicating that the secondary star is ‘behind’ the primary at periastron, a dispute extended over the past decade; c) a determination of the time of periastron passage, at ~4 days after the onset of the deep light curve minimum; and d) show that the minimum is simultaneous for observers at different lines of sight, indicating that it is not caused by an eclipse of the secondary star, but rather by the immersion of the wind-wind collision interior to the inner wind of the primary.
The Red Supergiant Content of the Local Group
Authors: Massey Philip , Levesque Emily , Neugent Kathryn , Evans Kate , Drout Maria , Beck Madeleine
Published: July 2017

We summarize here recent work in identifying and characterizing red supergiants (RSGs) in the galaxies of the Local Group.
The evolution of magnetic hot massive stars: Implementation of the quantitative influence of surface magnetic fields in modern models of stellar evolution
Authors: Keszthelyi Zsolt , Wade Gregg A. , Petit Véronique
Published: July 2017

Large-scale dipolar surface magnetic fields have been detected in a fraction of OB stars, however only few stellar evolution models of massive stars have considered the impact of these fossil fields. We are performing 1D hydrodynamical model calculations taking into account evolutionary consequences of the magnetospheric-wind interactions in a simplified parametric way. Two effects are considered: i) the global mass-loss rates are reduced due to mass-loss quenching, and ii) the surface angular momentum loss is enhanced due to magnetic braking. As a result of the magnetic mass-loss quenching, the mass of magnetic massive stars remains close to their initial masses. Thus magnetic massive stars - even at Galactic metallicity - have the potential to be progenitors of ‘heavy’ stellar mass black holes. Similarly, at Galactic metallicity, the formation of pair instability supernovae is plausible with a magnetic progenitor.
Dynamo Scaling Relationships
Authors: Augustson Kyle , Mathis Stéphane , Brun Sacha , Toomre Juri
Published: July 2017

This paper provides a brief look at dynamo scaling relationships for the degree of equipartition between magnetic and kinetic energies. Two simple models are examined, where one that assumes magnetostrophy and another that includes the effects of inertia. These models are then compared to a suite of convective dynamo simulations of the convective core of a main-sequence B-type star and applied to its later evolutionary stages.
What can magnetic early B-type stars tell us about early B-type stars in general?
Authors: Shultz Matthew , Wade Gregg , Rivinius Thomas , Neiner Coralie , Alecian Evelyne , Petit Véronique , Grunhut Jason ,   the MiMeS & BinaMIcS Collaborations
Published: July 2017

Some magnetic early B-type stars display Hα emission originating in their Centrifugal Magnetospheres (CMs). To determine the rotational and magnetic properties necessary for the onset of emission, we analyzed a large spectropolarimetric dataset for a sample of 51 B5-B0 magnetic stars. New rotational periods were found for 15 stars. We determined physical parameters, dipolar magnetic field strengths, magnetospheric parameters, and magnetic braking timescales. Hα-bright stars are more rapidly rotating, more strongly magnetized, and younger than the overall population. We use the high sensitivity of magnetic braking to the mass-loss rate to test the predictions of Vink et al. (2001) and Krtička (2014) by comparing agestto maximum spindown agestS, max. For stars withM*< 10M⊙this comparison favours the Krtička recipe. For the most massive stars, both prescriptions yieldt≪tS, max, a discrepancy which is difficult to explain via incorrect mass-loss rates alone.