bluuebunny/crossref_metadata_2025 huggingface dataset:
Varieties of capitalism, increasing income inequality and the sustainability of long-run growth
Authors: Setterfield Mark , Kim Yun K
Published: December 2019

We model US household debt accumulation during the neoliberal boom (1990–2007) as a response to emulation effects and the decline of the social wage, which has ‘privatised’ an increasing share of the costs of providing for services such as health and education. The debt dynamics of the US economy are then studied under alternative assumptions about the configuration of distributional variables, which is shown to differ across varieties of capitalism that have ‘neoliberalised’ to different degrees. A key result is that distributional change alone will not make contemporary US capitalism financially sustainable due, in part, to the paradoxical nature of inequality as a spur to household borrowing, and hence a source of both demand-formation and financial fragility. Achieving sustainability requires, instead, more wide-ranging reform.
Artificial Selection to a Nonlethal Cold Stress in Trogoderma variabile Shows Associations With Chronic Cold Stress and Body Size
Authors: Gerken Alison R , Abts Shelby R , Scully Erin D , Campbell James F
Published: December 2019

Extreme temperature has been used as an alternative to chemical treatments for stored product pests for years. Resistance to heat or cold treatments has not been documented in stored product insects, but repeated use of ineffective treatments could lead to adaptive tolerance. Trogoderma variabile (Dermestidae) is a common pest of stored products, and the larval stage is highly resistant to cold and destructive. We artificially selected populations by inducing chill coma at four different cold temperature treatments: 3 and 5 h at −10°C and 3 and 5 h at 0°C. Recovery time was highly heritable after selection for seven generations for decreased recovery time (cold tolerance) and increased recovery time (cold susceptibility) at all time and temperature combinations. Three replicate populations for each time and temperature combination varied substantially, suggesting different mutations in each population were probably responsible for selected phenotypes. Body size decreased in populations selected for cold susceptibility compared with those selected for cold tolerance and survivorship to long-term cold stress increased in the cold-tolerant populations compared with the susceptible populations. After the cessation of the selection experiment, cold tolerance dissipated within four generations from the populations at −10°C, but was maintained in populations exposed to 0°C. Our results suggest that warehouse beetles can adapt to cold stress quickly, but in the absence of cold stress, the proportion of cold-tolerant/susceptible individuals is quickly reduced, suggesting that some of the mutations responsible for these phenotypes may be associated with fitness costs under normal conditions.
A clinical comparison of the effectiveness of two types of orthodontic aligning archwire materials: a multicentre randomized clinical trial
Authors: Nabbat Sarah A , Yassir Yassir A
Published: December 2019

Objectives

To compare the heat-activated nickel titanium (HANT) with superelastic nickel-titanium (SENT) archwires in terms of their effectiveness of aligning teeth, possibility of inducing root resorption, and perception of pain.

Subjects and methods

Orthodontic patients aged 12 years or over with mandibular anterior crowding of 3–6 mm, who required treatment without extractions were randomly allocated (a simple non-stratified randomization) to the HANT and SENT archwires groups with a 1:1 allocation ratio. The archwire sequence in both groups was 0.014-inch and 0.016-inch, respectively. Each archwire was placed for 4 weeks. The outcome measures included the amount of crowding assessed blindly using Little’s irregularity index (LII), apical root resorption, and pain perception. The effectiveness of alignment was tested using 2 × 2 mixed factorial analysis of variance (ANOVA) model, while root resorption and pain perception were tested by the Mann–Whitney U-test and Wilcoxon signed-rank test (P < 0.05).

Results

Thirty-four patients were randomized and recruited from four centres, of those 31 were analysed (15 participants for the HANT and 16 for the SENT groups) with an overall mean age of 19.13 ± 5.73 years. The total reduction in the LII was 2.69 mm and 2.74 mm for the HANT and SENT groups, respectively. This did not reach the level of statistical (P = 0.809) or clinical significance. Similarly, root resorption and pain perception showed non-significant difference between groups. However, there was a slight increase in root resorption with the SENT group.

Limitations

A long-term evaluation of root resorption is required.

Conclusions

Both HANT and SENT archwires were equally effective in the aligning stage of orthodontic treatment. Root resorption with SENT wires should be monitored throughout treatment.

Registration

The trial was registered with ClinicalTrials.gov on 18 September 2019, registration number: NCT04090931.
Contrast and contact: civilians in French trench newspapers of the Great War*
Authors: Stice Elizabeth
Published: December 2019

This article looks at representations of civilians in French trench newspapers of the Great War to examine soldiers’ discourses about the wartime relationship between soldiers and civilians. Trench newspapers demonstrate that contrasting experiences of the war created tension and soldiers were sometimes frustrated by civilians. However, poilus also longed for contact with civilians and communication with them helped to sustain their resolve. While some earlier scholarship has suggested that Great War soldiers were considerably alienated from civilians, these sources, alongside newer scholarship, suggest that there was more than animosity and alienation between soldiers and civilians, at least in the French case. Trench newspapers also suggest the importance of intended audience in considering war-related narratives and suggest distinctions about the relationship between soldiers and civilians in the French case.
Mechanism of activation of plant monogalactosyldiacylglycerol synthase 1 (MGD1) by phosphatidylglycerol
Authors: Nitenberg Milène , Makshakova Olga , Rocha Joana , Perez Serge , Maréchal Eric , Block Maryse A , Girard-Egrot Agnès , Breton Christelle
Published: December 2019

Mono- and digalactosyldiacylglycerol are essential galactolipids for the biogenesis of plastids and functioning of the photosynthetic machinery. In Arabidopsis, the first step of galactolipid synthesis is catalyzed by monogalactosyldiacylglycerol synthase 1 (MGD1), a monotopic protein located in the inner envelope membrane of chloroplasts, which transfers a galactose residue from UDP-galactose to diacylglycerol (DAG). MGD1 needs anionic lipids such as phosphatidylglycerol (PG) to be active, but the mechanism by which PG activates MGD1 is still unknown. Recent studies shed light on the catalytic mechanism of MGD1 and on the possible PG binding site. Particularly, Pro189 was identified as a potential residue implicated in PG binding and His155 as the putative catalytic residue. In the present study, using a multifaceted approach (Langmuir membrane models, atomic force microscopy, molecular dynamics; MD), we investigated the membrane binding properties of native MGD1 and mutants (P189A and H115A). We demonstrated that both residues are involved in PG binding, thus suggesting the existence of a PG-His catalytic dyad that should facilitate deprotonation of the nucleophile hydroxyl group of DAG acceptor. Interestingly, MD simulations showed that MGD1 induces a reorganization of lipids by attracting DAG molecules to create an optimal platform for binding.
Adaptor protein complex 4 deficiency: a paradigm of childhood-onset hereditary spastic paraplegia caused by defective protein trafficking
Authors: Behne Robert , Teinert Julian , Wimmer Miriam , D’Amore Angelica , Davies Alexandra K , Scarrott Joseph M , Eberhardt Kathrin , Brechmann Barbara , Chen Ivy Pin-Fang , Buttermore Elizabeth D , Barrett Lee , Dwyer Sean , Chen Teresa , Hirst Jennifer , Wiesener Antje , Segal Devorah , Martinuzzi Andrea , Duarte Sofia T , Bennett James T , Bourinaris Thomas , Houlden Henry , Roubertie Agathe , Santorelli Filippo M , Robinson Margaret , Azzouz Mimoun , Lipton Jonathan O , Borner Georg H H , Sahin Mustafa , Ebrahimi-Fakhari Darius
Published: December 2019

Deficiency of the adaptor protein complex 4 (AP-4) leads to childhood-onset hereditary spastic paraplegia (AP-4-HSP): SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1) and SPG52 (AP4S1). This study aims to evaluate the impact of loss-of-function variants in AP-4 subunits on intracellular protein trafficking using patient-derived cells. We investigated 15 patient-derived fibroblast lines and generated six lines of induced pluripotent stem cell (iPSC)-derived neurons covering a wide range of AP-4 variants. All patient-derived fibroblasts showed reduced levels of the AP4E1 subunit, a surrogate for levels of the AP-4 complex. The autophagy protein ATG9A accumulated in the trans-Golgi network and was depleted from peripheral compartments. Western blot analysis demonstrated a 3–5-fold increase in ATG9A expression in patient lines. ATG9A was redistributed upon re-expression of AP4B1 arguing that mistrafficking of ATG9A is AP-4-dependent. Examining the downstream effects of ATG9A mislocalization, we found that autophagic flux was intact in patient-derived fibroblasts both under nutrient-rich conditions and when autophagy is stimulated. Mitochondrial metabolism and intracellular iron content remained unchanged. In iPSC-derived cortical neurons from patients with AP4B1-associated SPG47, AP-4 subunit levels were reduced while ATG9A accumulated in the trans-Golgi network. Levels of the autophagy marker LC3-II were reduced, suggesting a neuron-specific alteration in autophagosome turnover. Neurite outgrowth and branching were reduced in AP-4-HSP neurons pointing to a role of AP-4-mediated protein trafficking in neuronal development. Collectively, our results establish ATG9A mislocalization as a key marker of AP-4 deficiency in patient-derived cells, including the first human neuron model of AP-4-HSP, which will aid diagnostic and therapeutic studies.
Reflection on modern methods: cause of death decomposition of cohort survival comparisons
Authors: Canudas-Romo Vladimir , Adair Tim , Mazzuco Stefano
Published: December 2019

Life expectancy is most commonly measured for a period (corresponding to mortality within a given year) or for a specific birth cohort. Although widely used, period and cohort life expectancy have limitations as their time-trends often show disparities and can mask the historical mortality experience of all cohorts present at a given time. The truncated cross-sectional average length of life, or TCAL, is a period measure including all available cohort mortality information, irrespective of whether all cohort members have died. It is particularly useful for comparing cohort mortality between populations. This study extends TCAL by disentangling causes of death contributions. The strength of the approach is that it allows identification of mortality differences in cohorts with members still alive, as well as identification of which ages and causes of death contribute to mortality differentials between populations. Application of the method to Japan shows that over the period 1950–2014 a major contributor to TCAL differences with other high-longevity countries was its lower cardiovascular disease mortality.
Regulation of CRF mRNA in the Rat Extended Amygdala Following Chronic Cocaine: Sex Differences and Effect of Delta Opioid Receptor Agonism
Authors: Connelly Krista L , Unterwald Ellen M
Published: December 2019

Background

Cocaine withdrawal activates stress systems. Females are more vulnerable to relapse to cocaine use and more sensitive to withdrawal-induced negative affect. Delta opioid receptors modulate anxiety-like behavior during cocaine withdrawal in rats. This study measured the time course of gene regulation of one of the main stress peptides, corticotropin-releasing factor (CRF), and its type 1 receptor in male and female rats as well as the ability of the delta opioid receptor agonist SNC80 to normalize cocaine withdrawal-induced changes in CRF mRNA.

Methods

Rats were injected with cocaine or saline 3 times daily for 14 days. Brains were collected 30 minutes, 24 hours, 48 hours, 7 days, and 14 days following the last injection. The paraventricular nucleus of the hypothalamus, central amygdala, and bed nucleus of the stria terminalis were processed for quantitative reverse transcriptase PCR measurement of CRF and CRFR1 mRNA. Additional rats received SNC80 during early cocaine withdrawal, and CRF mRNA was measured in the central amygdala.

Results

CRF mRNA was elevated in the central amygdala at 24 hours and the paraventricular nucleus at 48 hours of cocaine withdrawal in males and females. Significant sex differences in cocaine-induced CRF upregulation were found in the bed nucleus of the stria terminalis at 30 minutes and 24 hours. SNC80 administration attenuated the increase in CRF mRNA in the central amygdala of female rats only.

Conclusions

CRF mRNA regulation during cocaine withdrawal is sex, time, and brain region dependent. Administration of a delta opioid receptor agonist during early withdrawal may ameliorate stress-related negative affect in females by abrogating the induction of CRF mRNA.
On the Classification of ALE Kähler Manifolds
Authors: Hein Hans-Joachim , Răsdeaconu Rareş , Şuvaina Ioana
Published: December 2019

The underlying complex structure of an ALE Kähler manifold is exhibited as a resolution of a deformation of an isolated quotient singularity. As a consequence, there exist only finitely many diffeomorphism types of minimal ALE Kähler surfaces with a given group at infinity.
The Orlicz Aleksandrov Problem for Orlicz Integral Curvature
Authors: Feng Yibin , He Binwu
Published: December 2019

In this paper, the Orlicz integral curvature is introduced, and some of its basic properties are discussed. The Orlicz Aleksandrov problem characterizing the Orlicz integral curvature is posed. The problem is solved in two situations when the given measure is even.
Integrin crosstalk allows CD4+ T lymphocytes to continue migrating in the upstream direction after flow
Authors: Kim Sarah Hyun Ji , Hammer Daniel A
Published: December 2019

In order to perform critical immune functions at sites of inflammation, circulatory T lymphocytes must be able to arrest, adhere, migrate and transmigrate on the endothelial surface. This progression of steps is coordinated by cellular adhesion molecules (CAMs), chemokines, and selectins presented on the endothelium. Two important interactions are between Lymphocyte Function-associated Antigen-1 (LFA-1) and Intracellular Adhesion Molecule-1 (ICAM-1) and also between Very Late Antigen-4 (VLA-4) and Vascular Cell Adhesion Molecule-1 (VCAM-1). Recent studies have shown that T lymphocytes and other cell types can migrate upstream (against the direction) of flow through the binding of LFA-1 to ICAM-1. Since upstream migration of T cells depends on a specific adhesive pathway, we hypothesized that mechanotransduction is critical to migration, and that signals might allow T-cells to remember their direction of migration after the flow is terminated. Cells on ICAM-1 surfaces migrate against the shear flow, but the upstream migration reverts to random migration after the flow is stopped. Cells on VCAM-1 migrate with the direction of flow. However, on surfaces that combine ICAM-1 and VCAM-1, cells crawl upstream at a shear rate of 800 s−1 and continue migrating in the upstream direction for at least 30 minutes after the flow is terminated—we call this ‘migrational memory’. Post-flow upstream migration on VCAM-1/ICAM-1 surfaces is reversed upon the inhibition of PI3K, but conserved with cdc42 and Arp2/3 inhibitors. Using an antibody against VLA-4, we can block migrational memory on VCAM-1/ICAM-1 surfaces. Using a soluble ligand for VLA-4 (sVCAM-1), we can promote migrational memory on ICAM-1 surfaces. These results indicate that, while upstream migration under flow requires LFA-1 binding to immobilized ICAM-1, signaling from VLA-4 and PI3K activity is required for the migrational memory of CD4+ T cells. These results indicate that crosstalk between integrins potentiates the signal of upstream migration.
Pharmacokinetics of trimethoprim/sulfametrole in critically ill patients on continuous renal replacement therapy
Authors: Welte René , Beyer Rudolph , Hotter Johannes , Broeker Astrid , Wicha Sebastian G , Gasperetti Tiziana , Ranke Paul , Zaruba Marc-Michael , Lorenz Ingo , Eschertzhuber Stephan , Ströhle Mathias , Bellmann-Weiler Rosa , Joannidis Michael , Bellmann Romuald
Published: December 2019

Objectives

We investigated the effect of continuous renal replacement therapy (CRRT) on the pharmacokinetics of trimethoprim and sulfametrole.

Patients and methods

We enrolled critically ill adults undergoing CRRT and critically ill adults with normal or slightly impaired renal function (plasma creatinine concentration <1.5 mg/dL, control group). All patients received trimethoprim/sulfametrole at standard doses. Pharmacokinetics were determined after the first dose and at steady-state. In addition, a population pharmacokinetic model using plasma data was built. We also assessed the renal clearance (CLR) and the extracorporeal clearance in patients undergoing CRRT.

Results

Twelve patients were enrolled in the CRRT group and 12 patients in the control group. There was no statistically significant difference in trimethoprim pharmacokinetics between the two groups. In patients on CRRT, total plasma clearance (CLtot) and V of sulfametrole were significantly higher than in the control group. However, sulfametrole exposure was not significantly altered during CRRT. The population pharmacokinetic analysis indicated that neither CRRT intensity nor residual diuresis were significant covariates on trimethoprim or sulfametrole CL. Median CL by continuous venovenous haemofiltration accounted for about one-third of CLtot of trimethoprim and for about one-half of CLtot of sulfametrole. In patients on CRRT, CLR of trimethoprim and sulfametrole were <5% of CLtot.

Conclusions

During CRRT, standard doses of trimethoprim/sulfametrole appear to be adequate.
Baseline Toxicity of the Insecticides Bifenthrin and Thiamethoxam on Halyomorpha halys (Hemiptera: Pentatomidae) Collected From the Eastern United States
Authors: Alford Adam , Kuhar Thomas P , Hamilton George C , Jentsch Peter , Krawczyk Grzgorz , Walgenbach James F , Welty Celeste
Published: December 2019

Brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive species in the United States that attacks a wide variety of agricultural commodities including fruits, vegetables, agronomic crops, and ornamental plants. Populations of H. halys adults were collected from four and six states in 2017 and 2018, respectively, and tested using topical applications to establish baseline levels of susceptibility to two commonly used insecticides, bifenthrin and thiamethoxam. A Probit-estimated (95% fiducial limits) LD50 and LD99 of 2.64 g AI/L (1.2–3.84 g AI/L) and 84.96 g AI/L (35.76–716.16 g AI/L) for bifenthrin, and a LD50 and LD99 of 0.05 g AI/liter (1.14E-5–0.27 g AI/L) and 150.11 g AI/L (27.35–761,867 g AI/L) for thiamethoxam, respectively. These baseline levels can be used for future insecticide resistance monitoring in H. halys.
The benefit and strategy of spring movements in Mongolian gazelles
Authors: Imai Shunsuke , Ito Takehiko Y , Shinoda Masato , Tsunekawa Atsushi , Lhagvasuren Badamjav
Published: December 2019

Animal movement is predicted to be nomadic in areas with low temporal predictability of environmental conditions, but it remains unclear whether the costs of nomadic movement outweigh the benefits received. To examine the spring movement strategy of Mongolian gazelles (Procapra gutturosa) in Mongolia, where predictability of vegetation conditions is relatively low, we identified the type of each movement, evaluated the preferred vegetation conditions for gazelles, and quantified the benefit achieved through each spring movement. The surveyed gazelles continuously preferred areas with intermediate normalized difference vegetation index (NDVI) values from May to July, and spatial and temporal shifts of the distribution of preferred areas explain the long-distance movements of many gazelles in spring. Three movement types, sedentary, linear, and nomadic movement, were identified. The period when benefit varied most greatly among individuals differed between the linear and nomadic movement types. During the spring movement period, the variance of benefit was larger for the nomadic movement type, whereas during the summer it was larger for the linear movement type, suggesting the existence of different movement strategies in the Mongolian gazelle. Linear long-distance movements over a short period in the linear movement type suggest the so-called jumper strategy, whereas other movement patterns might represent the searcher strategy. Benefit loss through movements of individuals in both strategies indicate low interannual predictability of vegetation conditions in the study area, and it would explain the co-existence of multiple movement types or strategies used by Mongolian gazelles in spring.
Constructing India as a Similar Enough Other: The Bush Administration's Strategic Narrative of the US-India Civil Nuclear Cooperation Agreement
Authors: Barthwal-Datta Monika
Published: December 2019

This article investigates how senior Bush administration officials publicly legitimized the administration's proposal for a United States-India Civil Nuclear Cooperation Agreement in 2005–2006, in their efforts to get the proposal approved by Congress. Adopting a critical constructivist approach, I argue that the Bush administration's proposed nuclear deal with India, a nonparty to the Nuclear Non-Proliferation Treaty (NPT), clashed with, and destabilized, official United States self-identity representations as a creator/upholder of the global nuclear nonproliferation regime. The Bush administration's efforts to mediate this conflict took the form of a strategic issue narrative, to create a discursive “moment of possibility” for the proposed policy shift. This narrative drew on existing United States discourses of India's subject positions and naturalized the latter as a Similar Enough Other deserving exception under United States, and global, nonproliferation regimes. The narrative aligned these constructions of India, and of the proposed deal as an “unprecedented opportunity” for the United States to forge closer strategic relations with India, with representations of a global order as shifting toward Asia. In doing so, it reoriented United States-India relations toward a highly desirable future, contingent on congressional approval of the proposed deal. The analysis makes an important conceptual contribution to the literature on strategic narratives, and critical constructivist scholarship more broadly, by illuminating how policy actors use strategic issue narratives, and the construction of specific subject positions therein, to redraw the boundaries of acceptable action vis-à-vis an Other that, at first glance, seems precluded in the prevailing normative-discursive environment.
Gender, Events, and Elite Messages in Mass Opinion on Foreign Relations
Authors: Bae Joonbum , Lee YuJung Julia
Published: December 2019

Do women respond in different ways to foreign policy events and elite messages compared to men? This article integrates the literature on gender and conflict with that on public opinion to examine how gender matters for the effect of elite messages and national security events on public opinion regarding a foreign adversary. We theorize that women’s opinions of an adversary are more likely than men’s to be influenced by national security events because of the higher value they attach to the costs of conflict. Our empirical analysis takes advantage of the natural setting of inter-Korea relations, which includes unpredictable, thus plausibly exogenous, real-world national security events instigated by North Korea and contrasting messages regarding North Korea by South Korea’s elites during this timeframe. Using annual survey data from a nationally representative sample of South Koreans about attitudes toward North Korea from 2003 to 2016, we find that foreign policy events of high consequence for national security have a greater negative impact on women’s opinions. This is the case even in the face of positive elite messages that contradict those events.
Recurrent convolutional neural networks for poet identification
Authors: Salami Dariush , Momtazi Saeedeh
Published: December 2019

Deep neural networks have been widely used in various language processing tasks. Recurrent neural networks (RNNs) and convolutional neural networks (CNN) are two common types of neural networks that have a successful history in capturing temporal and spatial features of texts. By using RNN, we can encode input text to a lower space of semantic features while considering the sequential behavior of words. By using CNN, we can transfer the representation of input text to a flat structure to be used for classifying text. In this article, we proposed a novel recurrent CNN model to capture not only the temporal but also the spatial features of the input poem/verse to be used for poet identification. Considering the shortcomings of the normal RNNs, we try both long short-term memory and gated recurrent unit units in the proposed architecture and apply them to the poet identification task. There are a large number of poems in the history of literature whose poets are unknown. Considering the importance of the task in the information processing field, a great variety of methods from traditional learning models, such as support vector machine and logistic regression, to deep neural network models, such as CNN, have been proposed to address this problem. Our experiments show that the proposed model significantly outperforms the state-of-the-art models for poet identification by receiving either a poem or a single verse as input. In comparison to the state-of-the-art CNN model, we achieved 9% and 4% improvements in f-measure for poem- and verse-based tasks, respectively.
The role of psychologists in international migration research: Complementing other expertise and an interdisciplinary way forward
Authors: Schwartz Seth J , Walsh Sophie D , Ward Colleen , Tartakovsky Eugene , Weisskirch Robert S , Vedder Paul , Makarova Elena , Bardi Anat , Birman Dina , Oppedal Brit , Benish-Weisman Maya , Lorenzo-Blanco Elma I , Güngör Derya , Stevens Gonneke W J M , Benet-Martínez Veronica , Titzmann Peter F , Silbereisen Rainer K , Geeraert Nicolas ,   the Psychology of Migration Working Group
Published: December 2019

This research note addresses the current and potential future role of psychologists in the study of international migration. We review ways in which psychologists have contributed to the study of migration, as well as ways in which psychological scholarship could be integrated with work from other social science fields. Broadly, we discuss four major contributions that psychology brings to the study of international migration—studying migrants’ internal psychological experiences, incorporating a developmental perspective, conducting experimental studies, and integrating across levels of analysis. Given the position of psychology as a ‘hub science’ connecting more traditional social sciences with health and medical sciences, we argue for a more prominent role for psychologists within the study of international migration. Such a role is intended to complement the roles of other social scientists and to create a more interdisciplinary way forward for the field of migration studies. The research note concludes with an agenda for further scholarship on migration.
The first observed stellar occultations by the irregular satellite Phoebe (Saturn IX) and improved rotational period
Authors: Gomes-Júnior A R , Assafin M , Braga-Ribas F , Benedetti-Rossi G , Morgado B E , Camargo J I B , Vieira-Martins R , Desmars J , Sicardy B , Barry T , Campbell-White J , Fernández-Lajús E , Giles D , Hanna W , Hayamizu T , Hirose T , De Horta A , Horvat R , Hosoi K , Jehin E , Kerr S , Machado D I , Mammana L A , Maybour D , Owada M , Rahvar S , Snodgrass C
Published: December 2019

We report six stellar occultations by Phoebe (Saturn IX), an irregular satellite of Saturn, obtained between mid-2017 and mid-2019. The 2017 July 6 event was the first stellar occultation by an irregular satellite ever observed. The occultation chords were compared to a 3D shape model of the satellite obtained from Cassini observations. The rotation period available in the literature led to a sub-observer point at the moment of the observed occultations where the chords could not fit the 3D model. A procedure was developed to identify the correct sub-observer longitude. It allowed us to obtain the rotation period with improved precision compared to the currently known value from literature. We show that the difference between the observed and the predicted sub-observer longitude suggests two possible solutions for the rotation period. By comparing these values with recently observed rotational light curves and single-chord stellar occultations, we can identify the best solution for Phoebe’s rotational period as 9.27365 ± 0.00002 h. From the stellar occultations, we also obtained six geocentric astrometric positions in the ICRS as realized by the Gaia DR2 with uncertainties at the 1-mas level.
The frequency of very young galaxies in the local Universe – II. The view from SDSS spectra
Authors: Mamon Gary A , Trevisan Marina , Thuan Trinh X , Gallazzi Anna , Davé Romeel
Published: December 2019

Only a handful of galaxies in the local Universe appear to be very young. We estimate the fraction of very young galaxies (VYGs), defined as those with more than half their stellar masses formed within the last Gyr. We fit non-parametric star formation histories (SFHs) to ∼280 000 galaxy spectra from a flux- and volume-limited subsample of the Main Galaxy Sample (MGS) of the SDSS, which is also complete in mass-to-light ratio, thus properly accounting for passive galaxies of a given mass. The VYG fractions decrease with increasing galaxy stellar mass, from ∼50 per cent at $m = 10^8\, {\rm M}_{\odot }$ to ∼0.1 per cent at $m = 10^{11.5}\, {\rm M}_{\odot }$, with differences of up to 1 dex between the different spectral models used to estimate the SFH and on how we treat aperture effects. But old stellar populations may hide in our VYGs despite our conservative VYG sample built with galaxies that are globally bluer than within the region viewed by the SDSS fibre. The VYG fractions versus mass decrease more gradually compared to the Tweed et al. predictions using analytical and semi-analytical models of galaxy formation, but agree better with the SIMBA hydrodynamical simulation. These discrepancies highlight the usefulness of VYGs in constraining the strong uncertainties in both galaxy formation models and spectral modelling of galaxy SFHs. Given the lognormal cosmic SFH, these mean VYG fractions suggest that galaxies above $10^8\, \rm M_\odot$ undergo at most four major starbursts on average.
SILCC-Zoom: H2 and CO-dark gas in molecular clouds – the impact of feedback and magnetic fields
Authors: Seifried D , Haid S , Walch S , Borchert E M A , Bisbas T G
Published: December 2019

We analyse the CO-dark molecular gas content of simulated molecular clouds from the SILCC-Zoom project. The simulations reach a resolution of 0.1 pc and include H2 and CO formation, radiative stellar feedback and magnetic fields. CO-dark gas is found in regions with local visual extinctions $A_\rm {V, 3D} \sim$ 0.2–1.5, number densities of 10–103 cm−3 and gas temperatures of few 10–100 K. CO-bright gas is found at number densities above 300 cm−3 and temperatures below 50 K. The CO-dark gas fractions range from 40 per cent to 95 per cent and scale inversely with the amount of well-shielded gas ($A_\rm {V, 3D}$ ≳ 1.5), which is smaller in magnetized molecular clouds. We show that the density, chemical abundances and $A_\rm {V, 3D}$ along a given line-of-sight cannot be properly determined from projected quantities. As an example, pixels with a projected visual extinction of $A_\rm {V, 2D} \simeq$ 2.5–5 can be both, CO-bright or CO-dark, which can be attributed to the presence or absence of strong density enhancements along the line-of-sight. By producing synthetic CO(1-0) emission maps of the simulations with RADMC-3D, we show that about 15–65 per cent of the H2 is in regions with intensities below the detection limit. Our clouds have $X_\rm {CO}$-factors around 1.5 × 1020 cm−2 (K km s−1)−1 with a spread of up to a factor ∼ 4, implying a similar uncertainty in the derived total H2 masses and even worse for individual pixels. Based on our results, we suggest a new approach to determine the H2 mass, which relies on the availability of CO(1-0) emission and $A_\rm {V, 2D}$ maps. It reduces the uncertainty of the clouds’ overall H2 mass to a factor of ≲ 1.8 and for individual pixels, i.e. on sub-pc scales, to a factor of ≲ 3.
Parallel Seed Color Adaptation during Multiple Domestication Attempts of an Ancient New World Grain
Authors: Stetter Markus G , Vidal-Villarejo Mireia , Schmid Karl J
Published: December 2019

Thousands of plants have been selected as crops; yet, only a few are fully domesticated. The lack of adaptation to agroecological environments of many crop plants with few characteristic domestication traits potentially has genetic causes. Here, we investigate the incomplete domestication of an ancient grain from the Americas, amaranth. Although three grain amaranth species have been cultivated as crop for millennia, all three lack key domestication traits. We sequenced 121 crop and wild individuals to investigate the genomic signature of repeated incomplete adaptation. Our analysis shows that grain amaranth has been domesticated three times from a single wild ancestor. One trait that has been selected during domestication in all three grain species is the seed color, which changed from dark seeds to white seeds. We were able to map the genetic control of the seed color adaptation to two genomic regions on chromosomes 3 and 9, employing three independent mapping populations. Within the locus on chromosome 9, we identify an MYB-like transcription factor gene, a known regulator for seed color variation in other plant species. We identify a soft selective sweep in this genomic region in one of the crop species but not in the other two species. The demographic analysis of wild and domesticated amaranths revealed a population bottleneck predating the domestication of grain amaranth. Our results indicate that a reduced level of ancestral genetic variation did not prevent the selection of traits with a simple genetic architecture but may have limited the adaptation of complex domestication traits.
Polygenic Patterns of Adaptive Introgression in Modern Humans Are Mainly Shaped by Response to Pathogens
Authors: Gouy Alexandre , Excoffier Laurent
Published: December 2019

Anatomically modern humans carry many introgressed variants from other hominins in their genomes. Some of them affect their phenotype and can thus be negatively or positively selected. Several individual genes have been proposed to be the subject of adaptive introgression, but the possibility of polygenic adaptive introgression has not been extensively investigated yet. In this study, we analyze archaic introgression maps with refined functional enrichment methods to find signals of polygenic adaptation of introgressed variants. We first apply a method to detect sets of connected genes (subnetworks) within biological pathways that present higher-than-expected levels of archaic introgression. We then introduce and apply a new statistical test to distinguish between epistatic and independent selection in gene sets of present-day humans. We identify several known targets of adaptive introgression, and we show that they belong to larger networks of introgressed genes. After correction for genetic linkage, we find that signals of polygenic adaptation are mostly explained by independent and potentially sequential selection episodes. However, we also find some gene sets where introgressed variants present significant signals of epistatic selection. Our results confirm that archaic introgression has facilitated local adaptation, especially in immunity related and metabolic functions and highlight its involvement in a coordinated response to pathogens out of Africa.
Dynamics of DNA nicking and unwinding by the RepC–PcrA complex
Authors: Carrasco Carolina , Pastrana Cesar L , Aicart-Ramos Clara , Leuba Sanford H , Khan Saleem A , Moreno-Herrero Fernando
Published: December 2019

The rolling-circle replication is the most common mechanism for the replication of small plasmids carrying antibiotic resistance genes in Gram-positive bacteria. It is initiated by the binding and nicking of double-stranded origin of replication by a replication initiator protein (Rep). Duplex unwinding is then performed by the PcrA helicase, whose processivity is critically promoted by its interaction with Rep. How Rep and PcrA proteins interact to nick and unwind the duplex is not fully understood. Here, we have used magnetic tweezers to monitor PcrA helicase unwinding and its relationship with the nicking activity of Staphylococcus aureus plasmid pT181 initiator RepC. Our results indicate that PcrA is a highly processive helicase prone to stochastic pausing, resulting in average translocation rates of 30 bp s−1, while a typical velocity of 50 bp s−1 is found in the absence of pausing. Single-strand DNA binding protein did not affect PcrA translocation velocity but slightly increased its processivity. Analysis of the degree of DNA supercoiling required for RepC nicking, and the time between RepC nicking and DNA unwinding, suggests that RepC and PcrA form a protein complex on the DNA binding site before nicking. A comprehensive model that rationalizes these findings is presented.
Is Youth Football Safe? An Analysis of Youth Football Head Impact Data
Authors: Heary Robert F , Majmundar Neil , Nagurka Roxanne
Published: December 2019

BACKGROUND

The issue of whether sports-related head trauma at the youth level can result in long-term sequelae that may negatively impact the participant has been widely debated.

OBJECTIVE

To investigate head impacts in the Summit Youth Football League equipped with helmets using the Riddell InSite impact monitoring system. The monitoring system allowed for analysis of the number of impacts and severity of impacts by player.

METHODS

Data were obtained for all 20 members of the youth football team. Impacts were recorded as “low,” “medium,” and “high” intensity.

RESULTS

All 20 players participated in all practices and games throughout the season. No player suffered a concussion throughout the entire season. There were 817 recorded impacts throughout the season. This was an average of 41 impacts per player over the course of the season and fewer than 4 impacts per player per week. Only one impact registered as “high.”

CONCLUSION

We demonstrate that there are few head impacts over the course of an entire season at the middle school level. Guardian Caps, safe tackling techniques, and the age of participants may have contributed to the very low number of impacts recorded and the complete lack of injuries. This study only provides data demonstrating that youth football, when Guardian Caps and safe tackling techniques are enforced, does not appear to result in significant head impacts causing immediate head injuries. This study cannot comment on the safety of playing football at the collegiate or professional level.
Convergent genomic signatures of high-altitude adaptation among domestic mammals
Authors: Wu Dong-Dong , Yang Cui-Ping , Wang Ming-Shan , Dong Kun-Zhe , Yan Da-Wei , Hao Zi-Qian , Fan Song-Qing , Chu Shu-Zhou , Shen Qiu-Shuo , Jiang Li-Ping , Li Yan , Zeng Lin , Liu He-Qun , Xie Hai-Bing , Ma Yun-Fei , Kong Xiao-Yan , Yang Shu-Li , Dong Xin-Xing , Esmailizadeh Ali , Irwin David M , Xiao Xiao , Li Ming , Dong Yang , Wang Wen , Shi Peng , Li Hai-Peng , Ma Yue-Hui , Gou Xiao , Chen Yong-Bin , Zhang Ya-Ping
Published: December 2019

Abundant and diverse domestic mammals living on the Tibetan Plateau provide useful materials for investigating adaptive evolution and genetic convergence. Here, we used 327 genomes from horses, sheep, goats, cattle, pigs and dogs living at both high and low altitudes, including 73 genomes generated for this study, to disentangle the genetic mechanisms underlying local adaptation of domestic mammals. Although molecular convergence is comparatively rare at the DNA sequence level, we found convergent signature of positive selection at the gene level, particularly the EPAS1 gene in these Tibetan domestic mammals. We also reported a potential function in response to hypoxia for the gene C10orf67, which underwent positive selection in three of the domestic mammals. Our data provide an insight into adaptive evolution of high-altitude domestic mammals, and should facilitate the search for additional novel genes involved in the hypoxia response pathway.
White matter tract-specific alterations in male patients with untreated obstructive sleep apnea are associated with worse cognitive function
Authors: Koo Dae Lim , Kim Hye Ryun , Kim Hosung , Seong Joon-Kyung , Joo Eun Yeon
Published: December 2019

Study Objectives

Neurocognitive impairment is one of the daytime symptoms of obstructive sleep apnea (OSA). We proposed to use tract-specific statistical analysis (TSSA) to investigate whether there are fiber tract abnormalities in OSA, which may be undiscovered using voxel-based approaches, and whether such tract-specific disruptions in brain connectivity are associated with neuropsychological deficits in patients with untreated OSA.

Methods

We enrolled 38 patients with OSA diagnosed by overnight polysomnography, and 41 healthy sleepers. Fractional anisotropy (FA) and mean diffusivity (MD) maps were obtained from whole-brain diffusion tensor imaging, and TSSA were used to assess regional deficits of white matter tracts. All participants underwent a battery of neuropsychological tests. To evaluate the association between FA values and clinical, polysomnographic, and neuropsychological parameters in the OSA group, permutation-based tests for correlation were performed preceding cluster-based statistics.

Results

Compared to healthy controls, patients with OSA showed decreased values of FA in the left and right anterior thalamic radiations, and right uncinate fasciculus (UNC) (p < 0.001, p = 0.005, and p = 0.008, respectively). A lower score of digit span backward was associated with lower FA values of right UNC in the OSA group (p = 0.023). The Rey Complex Figure Test copy score revealed a positive correlation with FA values in the right UNC (p = 0.010).

Conclusions

The TSSA method indeed identified previously unrevealed tract-specific disruptions in OSA. Furthermore, reduced FA values in the frontal lobe portion of the right UNC which has been known to be involved in working memory function were significantly associated with lower cognitive performance in patients with untreated OSA.
Characteristics and Outcomes of Autoimmune Hepatitis from a Tertiary Paediatric Centre, Cape Town, South Africa
Authors: Yassin Sawsan , De Lacy Ronalda , Pillay Komala , Goddard Elizabeth
Published: December 2019

Objectives

To describe the clinical characteristics, biochemical and histological features, outcomes and predictors of prognosis of children with autoimmune hepatitis (AIH) from a paediatric centre in South Africa.

Methods

Thirty-nine children diagnosed with AIH at Red Cross War Memorial Children’s Hospital between 2005 and 2015 were included. Relevant patient’s data were retrieved from the hospital’s medical records and database. Liver biopsy slides were reviewed. Ethical approval was obtained. Data were analysed using SPSS.

Results

Females were 29 (74%). Mean age at presentation was 7.27 ± 3.35 years and the mean follow-up was 4.5 ± 2.4 years. Jaundice was present in 97% of patients at presentation. An acute presentation was observed in 26 (67%) even though cirrhosis was detected in 22 (56%). Autoantibody screening was completed in 35 patients, 20 (57%) were AIH-1, 1 (3%) was AIH-2 and 14 (40%) were seronegative AIH. Of the 25 patients who underwent magnetic resonance cholangiography 17 (68%) had associated autoimmune sclerosing cholangitis. The remission rate was 79%. However, 11 children relapsed later. One child required liver transplantation and one demised. Seronegative and seropositive patients have comparable characteristics and outcomes. While a higher alanine transaminase (ALT) level at presentation is a significant predictor of remission, a lower ALT level and cirrhosis are significant risk factors for unfavourable outcome. Overall survival rate was 97%.

Conclusion

AIH responds well to therapy with excellent survival. Hence, it should be considered in any child presenting with viral screen negative hepatitis and start therapy timeously to prevent disease progression.
Virulence of Leaf Rust Physiological Races in Iran From 2010 to 2017
Authors: Nemati Zahra , Mostowfizadeh-Ghalamfarsa Reza , Dadkhodaie Ali , Mehrabi Rahim , Steffenson Brian J.
Published: December 2019

The wheat leaf rust fungus, Puccinia triticina, has widespread geographical distribution in Iran within the Fertile Crescent region of the Middle East where wheat was domesticated and P. triticina originated. Therefore, it is of great importance to identify the prevalence and distribution of P. triticina pathotypes in this area. From 2010 to 2017, 241 single-uredinium isolates of P. triticina were purified from 175 collections of P. triticina made from various hosts in 14 provinces of Iran, and they were tested on 20 Thatcher near-isogenic lines carrying single-leaf rust resistance genes. In total, 86 pathotypes were identified, of which the pathotypes FDTTQ, FDKPQ, FDKTQ, and FDTNQ were most prevalent. No virulence for Lr2a was detected, whereas virulence for Lr1 was found only on bread wheat in a few provinces in 2016. Only isolates from durum wheat and wild barley were virulent to Lr28. Although virulence for Lr9, Lr20, and Lr26 was observed in some years, the virulence frequency for these genes was lower than that of the other Lr genes. P. triticina collections from host plants with different ploidy levels or genetically dissimilar backgrounds were grouped individually according to genetic distance. Based on these results, collections from barley, durum wheat, oat, triticale, and wild barley were different from those of bread wheat.