bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite time blow-up of complex solutions of the conserved Kuramoto–Sivashinsky equation in ℝdand in the torus 𝕋d,d⩾ 1
Authors: Agélas Léo 
Published: January 2019

AbstractWe consider complex-valued solutions of the conserved Kuramoto–Sivashinsky equation which describes the coarsening of an unstable solid surface that conserves mass and that is parity symmetric. This equation arises in different aspects of surface growth. Up to now, the problem of existence and smoothness of global solutions of such equations remained open in ℝdand in the torus 𝕋d,d⩾ 1. In this paper, we answer partially to this question. We prove the finite time blow-up of complex-valued solutions associated with a class of large initial data. More precisely, we show that there is complex-valued initial data that exists in every Besov space (and hence in every Lebesgue and Sobolev space), such that after a finite time, the complex-valued solution is in no Besov space (and hence in no Lebesgue or Sobolev space).
Negotiating the German Democratic Republic: Angolan student migration during the Cold War, 1976–90
Authors: Schenck Marcia C. 
Published: January 2019

AbstractThis article traces the experiences of Angolan students who attended East German institutions of higher education between Angolan independence and the fall of the Berlin Wall. Based on oral histories collected in Luanda from twenty-one returned Angolan students in 2015, triangulated with archival material from Angola and the GDR, it argues that students negotiated between accommodation and resistance in their everyday life at the university and beyond. Conscious of the importance of academic success and adaptation to the East German learning culture, Angolan students drew a line when regulations infringed on their personal freedom and responded by engaging East German officials in discussion or simply by circumnavigating the rules. The life history of a female student illustrates how she negotiated between responsibility to formal learning and personal needs within a controlling society. When one considers the conditions of Angolan student life in East Germany as a whole, it becomes apparent that the East German notion of the model foreign student did not map onto the complexities of Angolan student lives. This article sheds light on the student migration of a generation of Angolan post-independence technocrats, many of whom studied in the former East during the Cold War. Through the eyes of Angolan educational migrants, we see the limits and possibilities of the lives of foreign students in the GDR.
The Effect of Arctic Sea Ice Loss on the Hadley Circulation
Authors: Chemke R. , Polvani L. M. , Deser C. 
Published: January 2019

AbstractOne of the most robust responses of the climate system to future greenhouse gas emissions is the melting of Arctic sea ice. It is thus essential to elucidate its impacts on other components of the climate system. Here we focus on the response of the annual mean Hadley cell (HC) to Arctic sea ice loss using a hierarchy of model configurations: atmosphere only, atmosphere coupled to a slab ocean, and atmosphere coupled to a full‐physics ocean. In response to Arctic sea ice loss, as projected by the end of the 21st century, the HC shows negligible changes in the absence of ocean‐atmosphere coupling. In contrast, by warming the Northern Hemisphere thermodynamic coupling weakens the HC and expands it northward. However, dynamic coupling acts to cool the Northern Hemisphere which cancels most of this weakening and narrows the HC, thus opposing its projected expansion in response to increasing greenhouse gases.
Forage Species Swarm in Response to Coastal Upwelling
Authors: Benoit‐Bird Kelly. J. , Waluk Chad. M. , Ryan John P. 
Published: January 2019

AbstractWe observed the distribution and identity of forage species to infer behavioral changes in response to intraseasonal variation in the coastal upwelling ecosystem of Monterey Bay, California. While the biomass of forage species remained comparable, the small‐scale distribution of krill and anchovies was strongly affected by upwelling conditions. When regional upwelling influences were strong in the Bay, both species formed numerous discrete swarms and schools. During relaxation, both species were more diffusely distributed. Rather than gross changes in spatial distribution, a process that could take a long time for these relatively small animals, forage species responded to the short time scale dynamics that occur between days in the upwelling season with changes in their aggregative behavior. The behavioral responses observed highlight the need to study within‐season dynamics in upwelling systems in addition to their cumulative influence in order to understand the ecological processes of these productive systems.
Fluid Substitution and Shear Weakening in Clay‐Bearing Sandstone at Seismic Frequencies
Authors: Yin Hanjun , Borgomano Jan V. M. , Wang Shangxu , Tiennot Mathilde , Fortin Jérôme , Guéguen Yves 
Published: January 2019

AbstractUsing the forced oscillation method and the ultrasonic transmission method, we measure the elastic moduli of a clay‐bearing Thüringen sandstone under dry and water‐saturated conditions in a broad frequency band at [0.004–10, 106] Hz for different differential pressures up to 30 MPa. Under water‐saturated condition, clear dispersion and attenuation for Young's modulus, Poisson's ratio, and Bulk modulus are observed at seismic frequencies, except for shear modulus. The measured dispersion and attenuation are mainly attributed to the drained/undrained transition, which considers the experimentally undrained boundary condition. Gassmann's predictions are consistent with the measured undrained bulk moduli but not with the shear moduli. Clear shear weakening is observed, and this water‐softening effect is stronger at seismic frequencies than at ultrasonic frequencies where stiffening effect related to squirt flow may mask real shear weakening. The reduction in surface free energy due to chemical interaction between pore fluid and rock frame, which is not taken into account by Gassmann's theory, is the main reason for the departure from Gassmann's predictions, especially for this rock containing a large number of clay minerals.
Using Information Theory to Evaluate Directional Precipitation Interactions Over the West Sahel Region in Observations and Models
Authors: Liu Bessie Y. , Zhu Qing , Riley William J. , Zhao Lei , Ma Hongxu , Van Gordon Mollie , Larsen Laurel 
Published: January 2019

AbstractWater availability has historically been one of the most significant threats to African regional social and economic well‐being. Over the Sahel region, a megadrought during the 1960s and 1970s induced by an abrupt and substantial rainfall reduction caused widespread famine and death. The postdrought recovery, which is still ongoing, has been characterized by gradual increases in rainfall, but with dramatic fluctuations. The large negative human impacts, slow recovery, and variability raise important questions of why and how rainfall dynamics evolve and interact with other components of the regional climate system. Here we provide an observational assessment of rainfall interactions mechanisms (informed by directional transfer of information entropy) that regulate Sahel rainfall. We quantitatively demonstrate that (1) sea surface temperature over the Gulf of Guinea controls moisture advection and transport to the West Sahel region and (2) strong bidirectional interactions exist between local vegetation dynamics and rainfall patterns. Then we assess the directional interaction patterns from nine state‐of‐the‐art Earth System Models (ESMs). We find that most ESMs are able to represent either the unidirectional control of sea surface temperature on precipitation or the bidirectional interaction between vegetation and precipitation. However, none of the ESMs represents both interactive patterns. The GFDL and IPSL‐CM5A‐LR models successfully reproduced observed patterns over ~50% of the West Sahel region but were not accurate in reproducing observed precipitation regional trends or interannual variation. We propose that the directional information transfer is a powerful mechanistic benchmark to assess model fidelity at the process level.
The impact of early-life sub-therapeutic antibiotic treatment (STAT) on excessive weight is robust despite transfer of intestinal microbes
Authors: Schulfer Anjelique F , Schluter Jonas , Zhang Yilong , Brown Quincy , Pathmasiri Wimal , McRitchie Susan , Sumner Susan , Li Huilin , Xavier Joao B , Blaser Martin J 
Published: January 2019

Abstract
The high-fat, high-calorie diets of westernized cultures contribute to the global obesity epidemic, and early life exposure to antibiotics may potentiate those dietary effects. Previous experiments with mice had shown that sub-therapeutic antibiotic treatment (STAT)—even restricted to early life—affected the gut microbiota, altered host metabolism, and increased adiposity throughout the lifetime of the animals. Here we carried out a large-scale cohousing experiment to investigate whether cohousing STAT and untreated (Control) mice would transfer the STAT-perturbed microbiota and transmit its impact on weight. We exposed pregnant dams and their young offspring to either low-dose penicillin (STAT) or water (Control) until weaning, and then followed the offspring as they grew and endured a switch from normal to high-fat diet at week 17 of life. Cohousing, which started at week 4, rapidly approximated the microbiota within cages, lowering the weight of STAT mice relative to non-cohoused mice. The effect, however, varied between cages, and was restricted to the first 16 weeks when diet consisted of normal chow. Once mice switched to high-fat diet, the microbiota α- and β-diversity expanded and the effect of cohousing faded: STAT mice, again, were heavier than control mice independently of cohousing. Metabolomics revealed serum metabolites associated with STAT exposure, but no significant differences were detected in glucose or insulin tolerance. Our results show that cohousing can partly ameliorate the impact of STAT on the gut microbiota but not prevent increased weight with high-fat diet. These observations have implications for microbiota therapies aimed to resolve the collateral damage of antibiotics and their load on human obesity.
Utility of fluorescent heme analogue ZnPPIX to monitor conformational heterogeneity in vertebrate hexa-coordinated globins
Authors: Tangar Antonija , Derrien Valérie , Lei Ruipeng , Santiago Estevez Maria Jose , Sebban Pierre , Bernad Sophie , Miksovska Jaroslava 
Published: January 2019

Abstract
Here, we report the preparation and photo-physical characterization of hexa-coordinated vertebrate globins, human neuroglobin (hNgb) and cytoglobin (hCygb), with the native iron protoporphyrin IX (FePPIX) cofactor replaced by a fluorescent isostructural analogue, zinc protoporphyrin IX (ZnPPIX). To facilitate insertion of ZnPPIX into hexa-coordinated globins, apoproteins prepared via butanone extraction were unfolded by the addition of GuHCl and subsequently slowly refolded in the presence of ZnPPIX. The absorption/emission spectra of ZnPPIX reconstituted hCygb are similar to those observed for ZnPPIX reconstituted myoglobin whereas the absorption and emission spectra of ZnPPIX reconstituted hNgb are blue shifted by ∼2 nm. Different steady state absorption and emission properties of ZnPPIX incorporated in hCygb and hNgb are consistent with distinct hydrogen bonding interactions between ZnPPIX and the globin matrix. The fluorescence lifetime of ZnPPIX in hexa-coordinated globins is bimodal pointing towards increased heterogeneity of the heme binding cavity in hCygb and hNgb. ZnPPIX reconstituted Ngb binds to cytochrome c with the same affinity as reported for the native protein, suggesting that fluorescent analogues of Cygb and Ngb can be readily employed to monitor interactions between vertebrate hexa-coordinated globins and other proteins.
Shorter Sentence Length Maximizes Intelligibility and Speech Motor Performance in Persons With Dysarthria Due to Amyotrophic Lateral Sclerosis
Authors: Allison Kristen M. , Yunusova Yana , Green Jordan R. 
Published: January 2019

Purpose
The purpose of this study was to investigate the effect of sentence length on intelligibility and measures of speech motor performance in persons with amyotrophic lateral sclerosis (ALS) and to determine how these effects were influenced by dysarthria severity levels.

Method
One hundred thirty-one persons with ALS were included in this study, stratified into 4 dysarthria severity groups. All participants produced sentences from 5 to 15 words in length. Intelligibility, speaking rate, and measures of speech pausing behavior (i.e., total speech duration, total pause duration, and mean speech event duration) were measured for each sentence. Linear mixed-effects models were used to determine the effect of sentence length on speech measures for speakers at different dysarthria severity levels.

Results
Results showed that speech intelligibility significantly declined at longer sentence lengths only for the speakers with ALS who had more advanced dysarthria symptoms; however, speakers with mild-to-severe dysarthria showed significant declines in speaking rate and speech pausing behavior at longer sentence lengths.

Conclusions
Findings suggest that producing shorter sentences may help maximize intelligibility for speakers with moderate-to-severe dysarthria secondary to ALS and may be a beneficial compensatory strategy for preserving motor effort for all speakers with dysarthria secondary to ALS.
Magnetic and rotational quenching of the Λ effect
Authors: Käpylä P. J. 
Published: January 2019

Context. Differential rotation in stars is driven by the turbulent transport of angular momentum.Aims. Our aim is to measure and parameterize the non-diffusive contribution to the total (Reynolds plus Maxwell) turbulent stress, known as the Λ effect, and its quenching as a function of rotation and magnetic field.Methods. Simulations of homogeneous, anisotropically forced turbulence in fully periodic cubes are used to extract their associated turbulent Reynolds and Maxwell stresses. The forcing is set up such that the vertical velocity component dominates over the horizontal ones, as in turbulent stellar convection. This choice of the forcing defines the vertical direction. Additional preferred directions are introduced by the imposed rotation and magnetic field vectors. The angle between the rotation vector and the vertical direction is varied such that the latitude range from the north pole to the equator is covered. Magnetic fields are introduced by imposing a uniform large-scale field on the system. Turbulent transport coefficients pertaining to the Λ effect are obtained by fitting. The results are compared with analytic studies.Results. The numerical and analytic results agree qualitatively at slow rotation and low Reynolds numbers. This means that vertical (horizontal) transport is downward (equatorward). At rapid rotation the latitude dependence of the stress is more complex than predicted by theory. The existence of a significant meridional Λ effect is confirmed. Large-scale vorticity generation is found at rapid rotation when the Reynolds number exceeds a threshold value. The Λ effect is severely quenched by large-scale magnetic fields due to the tendency of the Reynolds and Maxwell stresses to cancel each other. Rotational (magnetic) quenching of Λ occurs at more rapid rotation (at lower field strength) in the simulations than in the analytic studies.Conclusions. The current results largely confirm the earlier theoretical results, and also offer new insights: the non-negligible meridional Λ effect possibly plays a role in the maintenance of meridional circulation in stars, and the appearance of large-scale vortices raises the question of their effect on the angular momentum transport in rapidly rotating stellar convective envelopes. The results regarding magnetic quenching are consistent with the strong decrease in differential rotation in recent semi-global simulations and highlight the importance of including magnetic effects in differential rotation models.
High-strength medium Mn quenching and partitioning steel with low yield ratio
Authors: He B. B. , Wang M. , Liu L. , Huang M. X. 
Published: January 2019

A new microstructural design is proposed to develop a strong and ductile quenching and partitioning (Q&P) steel with low yield ratio. This steel has a heterogeneous dual phase microstructure which is developed by varying austenite thermal stability through Mn segregation. The heterogeneous microstructure contains large austenite grains which contribute to the low yield strength. The ultra-high tensile strength and good ductility are ascribed to the enhanced strain hardening behaviour resulted from the continuous transformation-induced plasticity (TRIP) effect. The present microstructural design enables a conventional medium Mn steel with high tensile strength, good ductility and low yield ratio, which promises easy forming and potential applications in automotive industries. This paper is part of a Thematic Issue on Medium Manganese Steels.
A near-chromosome-scale genome assembly of the gemsbok (Oryx gazella): an iconic antelope of the Kalahari desert
Authors: Farré Marta , Li Qiye , Zhou Yang , Damas Joana , Chemnick Leona G , Kim Jaebum , Ryder Oliver A , Ma Jian , Zhang Guojie , Larkin Denis M , Lewin Harris A 
Published: January 2019

Abstract

Background
The gemsbok (Oryx gazella) is one of the largest antelopes in Africa. Gemsbok are heterothermic and thus highly adapted to live in the desert, changing their feeding behavior when faced with extreme drought and heat. A high-quality genome sequence of this species will assist efforts to elucidate these and other important traits of gemsbok and facilitate research on conservation efforts.

Findings
Using 180 Gbp of Illumina paired-end and mate-pair reads, a 2.9 Gbp assembly with scaffold N50 of 1.48 Mbp was generated using SOAPdenovo. Scaffolds were extended using Chicago library sequencing, which yielded an additional 114.7 Gbp of DNA sequence. The HiRise assembly using SOAPdenovo + Chicago library sequencing produced a scaffold N50 of 47 Mbp and a final genome size of 2.9 Gbp, representing 90.6% of the estimated genome size and including 93.2% of expected genes according to Benchmarking Universal Single-Copy Orthologs analysis. The Reference-Assisted Chromosome Assembly tool was used to generate a final set of 47 predicted chromosome fragments with N50 of 86.25 Mbp and containing 93.8% of expected genes. A total of 23,125 protein-coding genes and 1.14 Gbp of repetitive sequences were annotated using de novo and homology-based predictions.

Conclusions
Our results provide the first high-quality, chromosome-scale genome sequence assembly for gemsbok, which will be a valuable resource for studying adaptive evolution of this species and other ruminants.
Factors That Explain Differences in Abstinence Between Black and White Smokers: A Prospective Intervention Study
Authors: Nollen Nicole L , Mayo Matthew S , Sanderson Cox Lisa , Benowitz Neal L , Tyndale Rachel F , Ellerbeck Edward F , Scheuermann Taneisha S , Ahluwalia Jasjit S 
Published: January 2019

Abstract

Background
Black-white differences in smoking abstinence are not well understood. This trial sought to confirm previously reported differences in quitting between blacks and whites and to identify factors underlying this difference.

Methods
During enrollment, 224 black and 225 white low-income smokers were stratified on race and within race on age and sex to ensure balance on these factors known to impact abstinence. The intervention included varenicline for 12 weeks and six guideline-based smoking cessation counseling sessions. The primary endpoint was cotinine-verified 7-day point prevalence smoking abstinence at week 26. A priori socioeconomic, smoking, treatment process (eg, treatment utilization, side effects, withdrawal relief), psychosocial, and biological factors were assessed to investigate race differences in abstinence. Unadjusted odds ratios (OR) were used to compare abstinence between blacks and whites. Adjusted odds ratios from logistic regression models were used to examine predictors of abstinence. All statistical tests were two-sided.

Results
Blacks were less likely to achieve abstinence at week 26 (14.3% vs 24.4%, OR = 0.51, 95% confidence interval [CI] = 0.32 to 0.83, P = .007). Utilizing best subsets logistic regression, five factors associated with race jointly predicted abstinence: home ownership (yes/no, OR = 3.03, 95% CI = 1.72 to 5.35, P < .001), study visits completed (range = 0–6, OR = 2.81, 95% CI = 1.88 to 4.20, P < .001), income (household member/$1000, OR = 1.03, 95% CI = 1.01 to 1.06, P = .02), plasma cotinine (per 1 ng/mL, OR = 0.997, 95% CI = 0.994 to 0.999, P = .002), and neighborhood problems (range = 10–30, OR = 0.88, 95% CI = 0.81 to 0.96, P = .003).

Conclusions
The race difference in abstinence was fully explained by lack of home ownership, lower income, greater neighborhood problems, higher baseline cotinine, and higher visit completion, which were disproportionately represented among blacks. Findings illuminate factors that make it harder for blacks in the United States to quit smoking relative to whites and provide important areas for future studies to reduce tobacco-related health disparities.
Trends in BRCA Test Utilization in an Integrated Health System, 2005–2015
Authors: Knerr Sarah , Bowles Erin J A , Leppig Kathleen A , Buist Diana S M , Gao Hongyuan , Wernli Karen J 
Published: January 2019

Abstract

Background
Genetic testing to determine BRCA status has been available for over two decades, but there are few population-based studies of test diffusion. We report 10-year trends in BRCAtesting in an integrated health-care system with long-standing access to genetic services.

Methods
A cohort of women aged 18 years and older was created to ascertain BRCA testing (n = 295 087). Annual testing rates between 2005 and 2015 were calculated in all women with and without incident (ie, newly diagnosed) breast and ovarian cancers and in clinically eligible subgroups by family cancer history, personal cancer history, and age at diagnosis. Secular trends were assessed using Poisson regression. Women tested early (2005–2008), midway (2009–2012), and late (2013–2015) in the study period were compared in cross-sectional analyses.

Results
Between 2005 and 2015, annual testing rates increased from 0.6/1000 person-years (pys) (95% confidence interval [CI] = 0.4 to 0.7/1000 pys) to 0.8/1000 pys (95% CI = 0.6 to 1.0/1000 pys) in women without incident breast or ovarian cancers. Rates decreased from 71.5/1000 pys (95% CI = 42.4 to 120.8/1000 pys) to 44.4/1000 pys (95% CI = 35.5 to 55.6/1000 pys) in women with incident diagnoses, despite improvements in provision of timely BRCA testing during this time frame. We found no evidence of secular trends in clinically eligible subgroups including women with family history indicating increased hereditary cancer risk, but no personal cancer history. At the end of the study period, 97.0% (95% CI = 96.6% to 97.3%) of these women remained untested.

Conclusion
Many eligible women did not receive BRCA testing despite having insurance coverage and access to specialty genetic services, underscoring challenges to primary and secondary hereditary cancer prevention.