bluuebunny/crossref_metadata_2025 huggingface dataset:
Quarter orbit maneuver using magnetorquer to maintain spacecraft angular momentum
Authors: Utama S , Hakim P R , Mukhayadi M
Published: May 2019

LAPAN-Tubsat, angular momentum is maintained by using magnetorquer in right ascension direction and gravity gradient in declination direction. Declination correction using gravity gradient in LAPAN-Tubsat only produce 1.5 °/day corrections for 5° gravity gradient. Must be noted that gravity gradient achieved by tilting the satellite, or require off-nadir attitude, this condition is not ideal for imaging mission. This paper introduces new method for angular momentum vector correction in declination direction by using magnetorquer. In this method certain coil current in y direction is set to produce magnetic torque. From previous research certain y coil current for one orbit will effectively change angular momentum’s right ascension. In this research y coil current is only set for a quarter orbits, hence torque resultant will only affect angular momentum’s declination. LAPAN-A3 satellite, 7° declination correction can be achieved by setting y coil current 30 mA for a quarter orbits or 23.5 minutes. Furthermore, by varying y coil current direction for each quarter orbit, 28° declination correction can be achieved in one full orbit. From this research can be seen that the new method is more efficient than the gravity gradient and also have advantage where the spacecraft will always in near nadir pointing.
Channel adaptive diversity handover with multiple queueing models for LEO equatorial satellites
Authors: Pratama R , Fadilah N
Published: May 2019

The development of satellite communication constellation in various countries has developed rapidly over the past decade. The satellite constellation in LEO orbit is chosen because of several advantages such as low power consumption, lower delay time, simple ground station, and high spectrum efficiency. Behind all the advantages in Low Earth Orbit, the main problem in LEO constellation is the mobility. Because of that, a handover is applied in LEO Constellation. The variation of satellite handover is Hard Handover, CASD Handover, or DDBHP handover. In this paper, the CASD model is used because it only uses one orbital plane and this model suppresses blocked and dropped calls. The modification is done by varying the queue model in this scheme, and which queuing model gives the best results. The best results of the research are in the FIFO model were carried out using the dual diversity scheme are 0.94% for blocked calls, 5.86% for dropped calls, and 93.2% for successful calls, and a total delay of 2.04 second of total simulation time for 30 seconds, caused incoming calls will be served sequentially so that no calls are served randomly and have more priority than other calls.
Power produced analysis of solar arrays in nadir pointing mode for low-earth equatorial micro-satellite conceptual design
Authors: Ribah A Z , Ramayanti S
Published: May 2019

We analyse the power produced by solar arrays in low-earth equatorial Micro-satellite conceptual design. The micro-satellite will be designed to be operated in nadir pointing mode, 1200 km of altitude, and equatorial orbit with 0 degree of inclination. Based on the profile, the mission of the satellite is operated suitably as LEO type communication satellite. To support the mission, the satellite needs to consider how much power provided from power resource; in this case, the satellite has solar arrays to obtain the power. Furthermore, the micro-satellite also has the body mounted solar array configuration, and these arrays are installed at the Z-, X+, and X- side of the satellite. However, to estimate the power output from the arrays, there are some problems that must be concerned, the first is the nadir pointing mode that makes the satellite must be pointed to nadir, and it causes the sunlight vector do not perpendicularly come into the solar arrays surface. The second problem is the sun position (equinox and solstice) that changes periodically throughout the year. Then, both can produce losses in producing power from the solar arrays. In this paper, the differences in produced power are analysed. Then the power produced in the Z-, X+, and X- sides in the two specific sun position become estimated. After that, we determine and analyse the ratio between average produced power and the maximum power produced.
Uniqueness of embeddings of the affine line into algebraic groups
Authors: Feller Peter , van Santen Immanuel
Published: May 2019

Let

Y
Y

be the underlying variety of a complex connected affine algebraic group. We prove that two embeddings of the affine line

C

\mathbb {C}

into

Y
Y

are the same up to an automorphism of

Y
Y

provided that

Y
Y

is not isomorphic to a product of a torus

(

C

∗

)
k

(\mathbb {C}^\ast )^k

and one of the three varieties

C

3

\mathbb {C}^3

,

SL
2

\operatorname {SL}_2

, and 

PSL
2

\operatorname {PSL}_2

.
Impacts of the MHC class I-like XNC10 and innate-like T cells on tumor tolerance and rejection in the amphibian Xenopus
Authors: Banach Maureen , Edholm Eva-Stina , Gonzalez Xavier , Benraiss Abdellatif , Robert Jacques
Published: May 2019

The conditions that lead to antitumor or protumor functions of natural killer T (NKT) cells against mammalian tumors are only partially understood. Therefore, insights into the evolutionary conservation of NKT and their analogs—innate-like T (iT) cells—may reveal factors that contribute to tumor eradication. As such, we investigated the amphibian Xenopus laevis iT cells and interacting MHC class I-like (XNC or mhc1b.L) genes against ff-2 thymic lymphoid tumors. Upon ff-2 intraperitoneal transplantation into syngeneic tadpoles, two iT cell subsets iVα6 and iVα22, characterized by an invariant T-cell receptor α chain rearrangement (Vα6-Jα1.43 and Vα22-Jα1.32 respectively), were recruited to the peritoneum, concomitant with a decreased level of these transcripts in the spleen and thymus. To address the hypothesize that different iT cell subsets have distinct, possibly opposing, roles upon ff-2 tumor challenge, we determined whether ff-2 tumor growth could be manipulated by impairing Vα6 iT cells or by deleting their restricting element, the XNC gene, XNC10 (mhc1b10.1.L), on ff-2 tumors. Accordingly, the in vivo depletion of Vα6 iT cells using XNC10-tetramers enhanced tumor growth, indicating Vα6 iT cell-mediated antitumor activities. However, XNC10-deficient transgenic tadpoles that also lack Vα6 iT cells were resistant to ff-2 tumors, uncovering a potential new function of XNC10 besides Vα6 iT cell development. Furthermore, the CRISPR/Cas9-mediated knockout of XNC10 in ff-2 tumors broke the immune tolerance. Together, our findings demonstrate the relevance of XNC10/iT cell axis in controlling Xenopus tumor tolerance or rejection.
Towards a Semantic Framework for Lifelong Integrated Competency Management and Development
Authors: Rezgui Kalthoum , Mhiri Hédia
Published: May 2019

In the domain of technology-enhanced competency-based learning and training, there is an increased interest in the integration of competency-related information for supporting competency-driven decision-making purposes. Indeed, since competency development draws upon several related areas, including teaching subjects, instructional design, learning resource annotation, e-Portfolios and motivated by the need for an integrated and semantic-based approach to competency management and development, a series of ontological structures have been formalized and developed for each of these areas. This paper aims to provide a framework specification for lifelong competency management and development, called LCMDF. The main advantage of this framework lies in its ability to provide a unifying semantic foundation in the form of a set of controlled vocabularies for describing competencies and their related details within the contexts of technology-enhanced competency-based learning and training. Moreover, this framework provides a novel integrated model to support a wide range of use cases. The proposed framework results from reusing widespread international standards for competency modeling which helps designing and implementing interoperability architecture of semantically-enhanced competency-based learning/human resource (HR) systems.
Global positioning system tracking devices can decrease Greater Sage-Grouse survival
Authors: Severson John P , Coates Peter S , Prochazka Brian G , Ricca Mark A , Casazza Michael L , Delehanty David J
Published: May 2019

Reliable demographic estimates hinge on the assumption that marking animals does not alter their behavior, reproduction, or survival. Violations can bias inference and are especially egregious for species of high conservation concern. Global positioning system (GPS) devices represent a recent technological advancement that has contributed greatly to avian ecological studies compared with traditionally used very high frequency (VHF) radio transmitters, but may affect demographic rates differently than VHF transmitters. We compared survival between VHF (necklace attachment) and GPS (rump-mounted attachment) devices from >1,100 Greater Sage-Grouse (Centrocercus urophasianus), a species of high conservation concern, across multiple populations within California and Nevada. We found lower survival for GPS-marked compared to VHF-marked sage-grouse across most sex, age, and seasonal comparisons. Estimates of annual survival for GPS-marked sage-grouse were 0.55–0.86 times that of VHF-marked birds with considerable variation among sex and age classes. Differences in survival could be attributed to features associated with GPS devices, including greater weight, position of attachment (e.g., rump-mount harness), and a semi-reflective solar panel. In a post hoc analysis, we evaluated additive and interactive effects between device type (GPS vs. VHF) and transmitter mass as a proportion of body mass (PBM). While the device type effect alone was the best model, the PBM interaction also had support. For GPS devices, survival decreased with increasing PBM, whereas PBM effects were not found for VHF. We attributed differences in PBM effect to placement of transmitters on sage-grouse, as weight of GPS devices was positioned rearward. This information can help managers and researchers weigh costs and benefits of GPS-based monitoring. Our results indicate demographic data collected from GPS devices should be interpreted with caution, and use of these devices should be tailored to specific ecological questions. Future research aimed at investigating behavioral impacts and GPS designs that reduce adverse impacts on survival would be beneficial.
Deregulation of Long Intergenic Non-coding RNAs in CD4+ T Cells of Lamina Propria in Crohn’s Disease Through Transcriptome Profiling
Authors: Braga-Neto Manuel B , Gaballa Joseph M , Bamidele Adebowale O , Sarmento Olga F , Svingen Phyllis , Gonzalez Michelle , Ramos Guilherme Piovezani , Sagstetter Mary R , Aseem Sayed Obaidullah , Sun Zhifu , Faubion William A
Published: May 2019

Background

The aetiology of Crohn’s disease [CD] involves immune dysregulation in a genetically susceptible individual. Genome-wide association studies [GWAS] have identified 200 loci associated with CD, ulcerative colitis, or both, most of which fall within non-coding DNA regions. Long non-coding RNAs [lncRNAs] regulate gene expression by diverse mechanisms and have been associated with disease activity in inflammatory bowel disease. However, disease-associated lncRNAs have not been characterised in pathogenic immune cell populations.

Methods

Terminal ileal samples were obtained from 22 CD patients and 13 controls. RNA from lamina propria CD4+ T cells was sequenced and long intergenic non-coding RNAs [lincRNAs] were detected. Overall expression patterns, differential expression [DE], and pathway and gene enrichment analyses were performed. Knockdown of novel lincRNAs XLOC_000261 and XLOC_000014 was performed. Expression of Th1 or Th17-associated transcription factors, T-bet and RORγt, respectively, was assessed by flow cytometry.

Results

A total of 6402 lincRNAs were expressed, 960 of which were novel. Unsupervised clustering and principal component analysis showed that the lincRNA expression discriminated patients from controls. A total of 1792 lincRNAs were DE, and 295 [79 novel; 216 known] mapped to 267 of 5727 DE protein-coding genes. The novel lincRNAs were enriched in inflammatory and Notch signalling pathways [p <0.05]. Furthermore, DE lincRNAs in CD patients were more frequently found in DNA regions with known inflammatory bowel disease [IBD]-associated loci. The novel lincRNA XLOC_000261 negatively regulated RORγt expression in Th17 cells.

Conclusions

We describe a novel set of DE lincRNAs in CD-associated CD4+ cells and demonstrate that novel lincRNA XLOC_000261 appears to negatively regulate RORγt protein expression in Th17 cells.
The CRISP-P study: feasibility of a self-completed colorectal cancer risk prediction tool in primary care
Authors: Harty Elena C , McIntosh Jennifer G , Bickerstaffe Adrian , Hewabandu Nadira , Emery Jon D
Published: May 2019

Objective

Australia and New Zealand have the highest incidence of colorectal cancer (CRC) globally. Our research team has developed a CRC risk prediction tool for use in primary care to increase targeted screening. This study, Colorectal cancer RISk Prediction tool – patient (‘CRISP-P’), aimed to determine the following to inform a future trial design: (i) the feasibility of self-reporting; (ii) the feasibility of recruitment methods; and (iii) the prevalence of CRC risk.

Methods

Participants aged between 40 and 75 years were recruited consecutively from three primary care waiting rooms. Participants input data into CRISP on a tablet without receiving clinical advice. Feasibility was evaluated using recruitment rate, timely completion, a self-reported ‘ease-of-use’, score and field notes. Prevalence of CRC risk was calculated using the CRISP model.

Results

Five hundred sixty-one (90%) patients agreed to use the tool and 424 (84%) rated the tool easy to use. Despite this, 41% of people were unable to complete the questions without assistance. Patients who were older, without tertiary education or with English as their second language were more likely to require assistance (P < 0.001). Thirty-nine percent of patients were low risk, 58% at slightly increased and 2.4% were at moderately increased risk of developing colorectal cancer in the next 5 years.

Conclusions

The tool was perceived as easy to use, although older, less educated people, and patients with English as their second language needed help. The data support the recruitment methods but not the use of a self-completed tool for an efficacy trial.
Characterization of two novel mutations in IL-12R signaling in MSMD patients
Authors: Fayez Elham Alipour , Koohini Zahra , Koohini Zohreh , Zamanzadeh Hossein , de Boer Martin , Roos Dirk , Teimourian Shahram
Published: May 2019

Mendelian Susceptibility to Mycobacterial Disease (MSMD) is a rare syndrome with infections—among other complications—after Bacillus Calmette-Guerin (BCG) vaccination in children. We focused on the IL-12/IFN-γ pathway to identify new mutations in our patients. This study included 20 patients by vulnerability to mycobacteria and clinical manifestations of severe, recurrent infections. Blood samples were activated with BCG, BCG + IL-12 and BCG + IFN-γ. Cytokine levels were analyzed by ELISA. Measurements of IL-12Rβ1 and IL-12Rβ2 on the surface of peripheral blood mononuclear cells were performed by flow cytometry. To detect genetic defects, next-generation sequencing was performed by Thermo Fisher immunodeficiency panel. Flow cytometry analysis of 20 patients indicated reduction in IL-12R (β1/β2) expression in seven patients who showed incomplete production of IFN-γ by ELISA. In the patient with reduced IL-12 production, IFN-γR and IL-12R (β1/β2) expression levels were normal. Mutation analysis showed three previously reported mutations, two novel mutations in IL-12 R (β1/β2), and one previously reported mutation in IL-12.
Socioeconomic Status Moderates Age Differences in Empathic Concern
Authors: Li Tianyuan , Siu Pok-Man
Published: May 2019

Objectives

Older age has been found to relate to a higher level of empathic concern and prosocial tendencies in many studies, but there are also studies that found contradictory results. To fully understand the phenomenon, we propose that socioeconomic status (SES) is an important factor to consider when examining differences in empathic concern and prosocial tendencies.

Method

Two studies with Hong Kong Chinese participants were conducted to test the moderating effect of SES on the relationship between age and empathic concern. Both studies assessed participants’ age, SES, empathic concern, and background information, while Study 2 also examined different indicators of prosocial tendencies.

Results

SES consistently moderated age differences in empathic concern in the two studies. The positive association between age and empathic concern was only significant for individuals with low SES, but not for those with high SES. Study 2 further revealed that the positive indirect effects from age to prosocial tendencies through a higher level of empathic concern were only significant for individuals with low SES as well.

Discussion

The results highlighted the importance to consider contextual factors when studying age-related differences.
Bayesian joint inversion of controlled source electromagnetic and magnetotelluric data to image freshwater aquifer offshore New Jersey
Authors: Blatter Daniel , Key Kerry , Ray Anandaroop , Gustafson Chloe , Evans Rob
Published: May 2019

Joint inversion of multiple electromagnetic data sets, such as controlled source electromagnetic and magnetotelluric data, has the potential to significantly reduce uncertainty in the inverted electrical resistivity when the two data sets contain complementary information about the subsurface. However, evaluating quantitatively the model uncertainty reduction is made difficult by the fact that conventional inversion methods—using gradients and model regularization—typically produce just one model, with no associated estimate of model parameter uncertainty. Bayesian inverse methods can provide quantitative estimates of inverted model parameter uncertainty by generating an ensemble of models, sampled proportional to data fit. The resulting posterior distribution represents a combination of a priori assumptions about the model parameters and information contained in field data. Bayesian inversion is therefore able to quantify the impact of jointly inverting multiple data sets by using the statistical information contained in the posterior distribution. We illustrate, for synthetic data generated from a simple 1-D model, the shape of parameter space compatible with controlled source electromagnetic and magnetotelluric data, separately and jointly. We also demonstrate that when data sets contain complementary information about the model, the region of parameter space compatible with the joint data set is less than or equal to the intersection of the regions compatible with the individual data sets. We adapt a trans-dimensional Markov chain Monte Carlo algorithm for jointly inverting multiple electromagnetic data sets for 1-D earth models and apply it to surface-towed controlled source electromagnetic and magnetotelluric data collected offshore New Jersey, USA, to evaluate the extent of a low salinity aquifer within the continental shelf. Our inversion results identify a region of high resistivity of varying depth and thickness in the upper 500 m of the continental shelf, corroborating results from a previous study that used regularized, gradient-based inversion methods. We evaluate the joint model parameter uncertainty in comparison to the uncertainty obtained from the individual data sets and demonstrate quantitatively that joint inversion offers reduced uncertainty. In addition, we show how the Bayesian model ensemble can subsequently be used to derive uncertainty estimates of pore water salinity within the low salinity aquifer.
Complex-conductivity monitoring to delineate aquifer pore clogging during nanoparticles injection
Authors: Flores Orozco Adrián , Micić Vesna , Bücker Matthias , Gallistl Jakob , Hofmann Thilo , Nguyen Frederic
Published: May 2019

Laboratory and field studies have demonstrated the applicability of nanoparticles (NP) for accelerated contaminant degradation. Beside other limitations (e.g. costs, delivery, longevity, non-target specific reactions), concerns of regulators arose regarding toxicity of injected NP and particles delivered off-target (i.e. renegade particles). Renegade particles also significantly reduce the efficiency of the remediation. The delivery of particles off-target is caused, mainly, by unintended fracking, where the fractures act then as preferential flow paths changing the trajectory of the particles. Hence, the real-time monitoring of particle injection is of major importance to verify correct particle delivery and thus help to optimize the remediation strategy. However, to date NP monitoring techniques rely on the analysis of soil and water samples, which cannot provide information about clogging or the formation of fractures away of the sampling points. To overcome these limitations, in this study we investigate the applicability of complex-conductivity imaging (CCI), a geophysical electrical method, to characterize possible pore clogging and fracking during NP injections. We hypothesize that both processes are related to different electrical footprints, considering the loss of porosity during clogging and the accumulation of NP in areas away of the target after fracking. Here, we present CCI results for data collected before and during the injection of Nano-Goethite particles (NGP) applied to enhance biodegradation of a BTEX (benzene, toluene, ethylbenzene and xylene) contaminant plume. Imaging results for background data revealed consistency with the known lithology, while overall high electrical conductivity values and a negligible induced-polarization magnitude correspond with the expected response of a mature hydrocarbon plume. Monitoring images revealed a general increase (∼15 per cent) in the electrical conductivity due to the injected NGP suspension in agreement with geochemical data. Furthermore, abrupt changes in this trend, shortly before daylighting events, show the sensitivity of the method to pore clogging. Such interpretation is in line with the larger variations in CCI resolved in the unsaturated zone, clearly indicating the accumulation of renegade NGP close to the surface due to fracking. Our results demonstrate the applicability of the CCI method for the assessment of pore clogging accompanying particles injection.
Immediate Transcriptional Response to a Temperature Pulse under a Fluctuating Thermal Regime
Authors: Melicher Dacotah , Torson Alex S , Anderson Tanner J , Yocum George D , Rinehart Joseph P , Bowsher Julia H
Published: May 2019

The response of ectotherms to temperature stress is complex, non-linear, and is influenced by life stage and previous thermal exposure. Mortality is higher under constant low temperatures than under a fluctuating thermal regime (FTR) that maintains the same low temperature but adds a brief, daily pulse of increased temperature. Long term exposure to FTR has been shown to increase transcription of genes involved in oxidative stress, immune function, and metabolic pathways, which may aid in recovery from chill injury and oxidative damage. Previous research suggests the transcriptional response that protects against sub-lethal damage occurs rapidly under exposure to fluctuating temperatures. However, existing studies have only examined gene expression after a week or over many months. Here we characterize gene expression during a single temperature cycle under FTR. Development of pupating alfalfa leafcutting bees (Megachile rotundata) was interrupted at the red-eye stage and were transferred to 6°C with a 1-h pulse to 20°C and returned to 6°C. RNA was collected before, during, and after the temperature pulse and compared to pupae maintained at a static 6°C. The warm pulse is sufficient to cause expression of transcripts that repair cell membrane damage, modify membrane composition, produce antifreeze proteins, restore ion homeostasis, and respond to oxidative stress. This pattern of expression indicates that even brief exposure to warm temperatures has significant protective effects on insects exposed to stressful cold temperatures that persist beyond the warm pulse. Megachile rotundata’s sensitivity to temperature fluctuations indicates that short exposures to temperature changes affect development and physiology. Genes associated with developmental patterning are expressed after the warm pulse, suggesting that 1 h at 20°C was enough to resume development in the pupae. The greatest difference in gene expression occurred between pupae collected after the warm pulse and at constant low temperatures. Although both were collected at the same time and temperature, the transcriptional response to one FTR cycle included multiple transcripts previously identified under long-term FTR exposure associated with recovery from chill injury, indicating that the effects of FTR occur rapidly and are persistent.
Accelerators and intra-ecosystem variety: how entrepreneurial agency influences venture development in a time-compressed support program
Authors: Qin Fei , Wright Mike , Gao Jian
Published: May 2019

Accelerator programs constitute an important new element in entrepreneurial ecosystems, comprising focused support to advance the development of entrepreneurial ventures. Yet, we lack understanding of the processes through which accelerators contribute to enhancing entrepreneurial activity and especially the role of entrepreneurship agency in this process. By systematically tracking a cohort of ventures in a leading accelerator, our study draws out intra ecosystem heterogeneity and reveals that the accelerator program elements can impose a distinctive direct effect on participating ventures but the effect varies as entrepreneurs adopt different approaches to engage other players in the ecosystem. We find that in order to fit in the temporal structure of the accelerator program, entrepreneurs adopt two different strategies to achieve accelerated venture development—acceleration with focus and acceleration with foresight. The effectiveness of these two acceleration strategies are moderated by the approaches to engaging the accelerator offerings for resource acquisition. By developing a theoretical framework of entrepreneurial acceleration in the accelerator setting, we contribute to the specific literatures on entrepreneurial process and accelerators and more generally to the emerging literature on the functioning of entrepreneurial ecosystems.
Oxytocin Facilitates Self-Serving Rather Than Altruistic Tendencies in Competitive Social Interactions Via Orbitofrontal Cortex
Authors: Xu Xiaolei , Liu Congcong , Zhou Xinqi , Chen Yuanshu , Gao Zhao , Zhou Feng , Kou Juan , Becker Benjamin , Kendrick Keith M
Published: May 2019

Background

While the neuropeptide oxytocin can facilitate empathy and altruistic behavior, it may also promote self-serving tendencies in some contexts, and it remains unclear if it would increase altruistic or self-interest behaviors when they compete within a social situation.

Methods

The current between-subject, double-blind, placebo-controlled fMRI study investigated the effect of intranasal oxytocin on empathy for social exclusion using a modified online ball-tossing game that incorporated monetary rewards and the potential to display both altruistic and self-interest behaviors.

Results

Results showed that when subjects in both oxytocin and placebo groups were observing a player being excluded (victim) by other players in the game, there was activation in the mentalizing network. When subjects then played both with the victim and the players who had excluded them, they threw more balls to the victim player, indicative of an altruistic response. However, subjects in the oxytocin group threw more balls to the excluder players indicative of greater self-interest, since the latter would be perceived as more likely to reciprocate to maximize financial gain. This behavioral effect of oxytocin was associated with greater medial orbitofrontal cortex activation when playing with the excluders and negatively correlated with trait-altruism scores.

Conclusions

Overall, our findings suggest that in the context of competing motivations for exhibiting altruistic or self-interest behavior, oxytocin enhanced self-interest and this was associated with greater activation in frontal reward areas.
The inf-sup stability of the lowest order Taylor–Hood pair on affine anisotropic meshes
Authors: Barrenechea Gabriel R , Wachtel Andreas
Published: May 2019

Uniform inf-sup conditions are of fundamental importance for the finite element solution of problems in incompressible fluid mechanics, such as the Stokes and Navier–Stokes equations. In this work we prove a uniform inf-sup condition for the lowest-order Taylor–Hood pairs $\mathbb{Q}_2\times \mathbb{Q}_1$ and $\mathbb{P}_2\times \mathbb{P}_1$ on a family of affine anisotropic meshes. These meshes may contain refined edge and corner patches. We identify necessary hypotheses for edge patches to allow uniform stability and sufficient conditions for corner patches. For the proof, we generalize Verfürth’s trick and recent results by some of the authors. Numerical evidence confirms the theoretical results.
Periods and Reciprocity I
Authors: Zacharias Raphaël
Published: May 2019

Given $\boldsymbol{F}$ a number field with ring of integers ${\mathcal{O}}_{\boldsymbol{F}}$ and ${\mathfrak{p}},{\mathfrak{q}}$ two coprime and squarefree ideals of ${\mathcal{O}}_{\boldsymbol{F}}$, we prove a reciprocity relation for the 1st moment of the triple product $L$-functions $L(\pi \otimes \pi _1\otimes \pi _2,\frac{1}{2})$ twisted by $\lambda _{\pi }({\mathfrak{p}})$, where $\pi _1$ and $\pi _2$ are fixed unitary automorphic representations of $\textrm{PGL}_2({\mathbb{A}}_{\boldsymbol{F}})$ with $\pi _1$ cuspidal and $\pi$ runs through unitary automorphic representations of conductor dividing ${\mathfrak{q}}$. The method uses adelic integral representations of $L$-functions and the symmetric identity is established for a particular period. Finally, the integral period is connected to the moment via Parseval formula.
Dynamic Changes in Ex Vivo T-Cell Function After Viral Clearance in Chronic HCV Infection
Authors: Han Ji Won , Sung Pil Soo , Kim Kyung Hwan , Hong Seon-Hui , Shin Eui-Cheol , Jun Song Myeong , Park Su-Hyung
Published: May 2019

Background

Direct-acting antiviral (DAA) agents can successfully treat chronic hepatitis C virus (HCV) infection. However, the ex vivo HCV-specific T-cell function following viral clearance remains unknown.

Methods

We investigated functional alterations and phenotypic changes in ex vivo HCV-specific CD8+ T cells with a longitudinal analysis of 41 patients with chronic HCV infection who were undergoing DAA treatment.

Results

A patient subset exhibited a significantly increased T-cell response (mainly CD8+ T cells) at week 4 of treatment. However, this increased T-cell response diminished in later weeks. Relative to pretreatment levels, the ex vivo HCV-specific CD8+ T-cell frequency decreased at 12 weeks after the end of treatment, along with a decreased antigen-experienced CD8+ T-cell population. DAA treatment increased the proliferative capacity of HCV-specific CD8+ T cells, but this change was not correlated with ex vivo function. Patients experiencing viral breakthrough or relapse exhibited defective restoration of T-cell function.

Conclusion

Our present results indicated that DAA-mediated viral clearance only transiently restored ex vivo T-cell function, suggesting a need to enhance T-cell function in DAA-treated patients.
Evaluation of genotype quality parameters for SowPro90, a new genotyping array for swine1
Authors: Wijesena Hiruni R , Rohrer Gary A , Nonneman Dan J , Keel Brittney N , Petersen Jessica L , Kachman Stephen D , Ciobanu Daniel C
Published: May 2019

Understanding early predictors of sow fertility has the potential to improve genomic predictions. A custom SNP array (SowPro90 produced by Affymetrix) was developed to include genetic variants overlapping quantitative trait loci for age at puberty, one of the earliest indicators of sow fertility, as well as variants related to innate and adaptive immunity. The polymorphisms included in the custom genotyping array were identified using multiple genomic approaches including deep genomic and transcriptomic sequencing and genome-wide associations. Animals from research and commercial populations (n = 2,586) were genotyped for 103,476 SNPs included in SowPro90. To assess the quality of data generated, genotype concordance was evaluated between the SowPro90 and Porcine SNP60 BeadArray using a subset of common SNP (n = 44,708) and animals (n = 277). The mean genotype concordance rate per SNP was 98.4%. Differences in distribution of data quality were observed between the platforms indicating the need for platform specific thresholds for quality parameters. The optimal thresholds for SowPro90 (≥97% SNP and ≥93% sample call rate) were obtained by analyzing the data quality distribution and genotype concordance per SNP across platforms. At ≥97% SNP call rate, there were 42,151 SNPs (94.3%) retained with a mean genotype concordance of 98.6% across platforms. Similarly, ≥94% SNPs and ≥85% sample call rates were established as thresholds for Porcine SNP60 BeadArray. At ≥94% SNPs call rate, there were 41,043 SNPs (91.8%) retained with a mean genotype concordance of 98.6% across platforms. Final evaluation of SowPro90 array content (n = 103,476) at ≥97% SNPs and ≥93% sample call rates allowed retention of 89,040 SNPs (86%) for downstream analysis. The findings and strategy for quality control could be helpful in identifying consistent, high-quality genotypes for genomic evaluations, especially when integrating genotype data from different platforms.
Delegation with a Reciprocal Agent
Authors: De Chiara Alessandro , Manna Ester
Published: May 2019

We consider a model in which a principal may delegate the choice of a project to a better informed agent. The preferences of the agent and the principal about which project should be undertaken may be discordant. Moreover, the agent benefits from being granted more discretion in the project choice and may be motivated by reciprocity. We find that the relationship between the agent’s reciprocity and discretion crucially depends on the conflict of interest with the principal. When preferences are more congruent (discordant), discretion is broader (more limited) if the agent is more reciprocal. Hence, reciprocity mitigates (exacerbates) a mild (severe) conflict of interest. We also present supportive evidence for the predictions of our model using the German Socio-Economic Panel dataset. (JEL D03, D82, D86)
Vegetation structure shapes small mammal communities in African savannas
Authors: Loggins Anne A , Monadjem Ara , Kruger Laurence M , Reichert Brian E , McCleery Robert A
Published: May 2019

Disturbance by large herbivores, fires, and humans shapes the structure of savannas, altering the amount of woody vegetation and grass. Due to change in the intensity and frequency of these disturbances, savannas are shifting toward grass-dominated or shrub-dominated systems, likely altering animal communities. Small mammals are critical components of savannas, and their distributions likely are affected by these ecosystem-wide changes in vegetative cover. We assessed the responses of small mammals to a gradient of woody cover in low-lying savannas of southeastern Africa. In Kruger National Park (South Africa) and in three nearby reserves (Eswatini), we livetrapped for over 2 years to build multispecies occupancy models that assessed the responses of the small mammal community to grass and woody cover. Overall, whole-community occupancy increased with grass biomass. More species responded positively to woody cover than to grass biomass, but woody cover was associated with reduced occurrence of one species (Mastomys natalensis). Our results suggest that an increase in grass biomass enhances whole-community occupancy of small mammals, but regional diversity is likely to be higher in areas that contain patches of high grass biomass as well as patches of woody cover.
Auto-regulatory feedback by RNA-binding proteins
Authors: Müller-McNicoll Michaela , Rossbach Oliver , Hui Jingyi , Medenbach Jan
Published: May 2019

RNA-binding proteins (RBPs) are key regulators in post-transcriptional control of gene expression. Mutations that alter their activity or abundance have been implicated in numerous diseases such as neurodegenerative disorders and various types of cancer. This highlights the importance of RBP proteostasis and the necessity to tightly control the expression levels and activities of RBPs. In many cases, RBPs engage in an auto-regulatory feedback by directly binding to and influencing the fate of their own mRNAs, exerting control over their own expression. For this feedback control, RBPs employ a variety of mechanisms operating at all levels of post-transcriptional regulation of gene expression. Here we review RBP-mediated autogenous feedback regulation that either serves to maintain protein abundance within a physiological range (by negative feedback) or generates binary, genetic on/off switches important for e.g. cell fate decisions (by positive feedback).
Physical Activity and the Risk of Liver Cancer: A Systematic Review and Meta-Analysis of Prospective Studies and a Bias Analysis
Authors: Baumeister Sebastian E , Leitzmann Michael F , Linseisen Jakob , Schlesinger Sabrina
Published: May 2019

Background

Physical inactivity is an established risk factor for several cancers of the digestive system and female reproductive organs, but the evidence for liver cancers is less conclusive.

Methods

The aim of this study was to synthesize prospective observational studies on the association of physical activity and liver cancer risk by means of a systematic review and meta-analysis. We searched Medline, Embase, and Scopus from inception to January 2019 for prospective studies investigating the association of physical activity and liver cancer risk. We calculated mean hazard ratios (HRs) and 95% confidence intervals (CIs) using a random-effects model. We quantified the extent to which an unmeasured confounder or an unaccounted selection variable could shift the mean hazard ratio to the null.

Results

Fourteen prospective studies, including 6,440 liver cancers, were included in the systematic review and meta-analysis. The mean hazard ratio for high compared with low physical activity was 0.75 (95% CI = 0.63 to 0.89; 95% prediction interval = 0.52 to 1.07; I² = 64.2%). We estimated that 67.6% (95% CI = 56.6% to 78.5%) of all true effect estimates would have a hazard ratio less than 0.8. Bias analysis suggested than an unobserved confounder would have to be associated with a 1.99-fold increase in the risk of physical activity or liver cancer to explain away the observed mean hazard ratio. An unaccounted for selection variable would have to be related to exposure and endpoint with a relative risk of 1.58 to explain away the mean hazard ratio.

Conclusions

Physical activity is inversely related to the risk of liver cancer. Further studies with objectively measured physical activity and quasi-experimental designs addressing confounding are needed.
The Relationship Between Insomnia and Cognitive Impairment in Breast Cancer Survivors
Authors: Liou Kevin T , Ahles Tim A , Garland Sheila N , Li Q Susan , Bao Ting , Li Yuelin , Root James C , Mao Jun J
Published: May 2019

Background

Cancer-related cognitive impairment is an emerging public health burden. Growing research suggests that sleep disturbances contribute to poor cognition. Our study aimed to evaluate the association between insomnia and cognitive impairment in breast cancer survivors.

Methods

We analyzed cross-sectional data from a cohort study of postmenopausal women with stage 0–III hormone receptor-positive breast cancer on aromatase inhibitor therapy. The study was conducted between November 2011 and April 2015 at an academic cancer center (Philadelphia, PA). Insomnia was assessed with the Insomnia Severity Index. Perceived cognitive impairment was assessed with the cognitive subscale of the Breast Cancer Prevention Trial Symptom Checklist. We used linear regression to evaluate the association between insomnia and perceived cognitive impairment.

Results

Among 1072 patients, 556 (51.9%) reported insomnia and 847 (79.0%) were bothered by cognitive symptoms (forgetfulness, difficulty concentrating, distractibility). Greater perceived cognitive impairment was reported by patients with mild insomnia (regression coefficient [β] = 0.35, 95% confidence interval [CI] = 0.23 to 0.46, P < .001), moderate insomnia (β = 0.51, 95% CI = 0.36 to 0.65, P < .001), and severe insomnia (β = 0.94, 95% CI = 0.67 to 1.21, P < .001), compared with those without insomnia. Greater perceived cognitive impairment was also associated with patients younger than 55 years (β = 0.30, 95% CI = 0.15 to 0.45, P < .001), taxane-based chemotherapy (β = 0.11, 95% CI = 0.004 to 0.22, P = .04), anxiety (β = 0.47, 95% CI = 0.30 to 0.64, P < .001), and depression (β = 0.65, 95% CI = 0.35 to 0.94, P < .001).

Conclusions

Among postmenopausal breast cancer survivors receiving aromatase inhibitor therapy, insomnia and cognitive impairment are prevalent and characterized by a graded association, in which severity of perceived cognitive impairment increases as insomnia severity increases. Our findings warrant further research to determine whether addressing sleep is a strategy to improve management of cancer-related cognitive impairment.
Robust velocity dispersion and binary population modelling of the ultrafaint dwarf galaxy Reticulum II
Authors: Minor Quinn E , Pace Andrew B , Marshall Jennifer L , Strigari Louis E
Published: May 2019

We apply a Bayesian method to model multi-epoch radial velocity measurements in the ultrafaint dwarf galaxy Reticulum II, fully accounting for the effects of binary orbital motion and systematic offsets between different spectroscopic data sets. We find that the binary fraction of Ret II is higher than 0.5 at the 90 per cent confidence level, if the mean orbital period is assumed to be 30 yr or longer. Despite this high-binary fraction, we infer a best-fitting intrinsic dispersion of 2.8$_{-1.2}^{+0.7}$ km s−1, which is smaller than the previous estimates but still indicates Ret II is a dark matter dominated galaxy. We likewise infer a ≲ 1 per cent probability that Ret II’s dispersion is due to binaries rather than dark matter (which would correspond to the regime $M/L \lesssim 2\, \mathrm{M}_\odot /\mathrm{L}_\odot$). Our inference of a high-close binary fraction in Ret II echoes previous results for the Segue 1 ultrafaint dwarf and is consistent with studies of Milky Way halo stars that indicate a high-close binary fraction tends to exist in metal-poor environments.
Evolution of the AGN UV luminosity function from redshift 7.5
Authors: Kulkarni Girish , Worseck Gábor , Hennawi Joseph F
Published: May 2019

Determinations of the ultraviolet (UV) luminosity function of active galactic nuclei (AGN) at high redshifts are important for constraining the AGN contribution to reionization and understanding the growth of supermassive black holes. Recent inferences of the luminosity function suffer from inconsistencies arising from inhomogeneous selection and analysis of data. We address this problem by constructing a sample of more than 80 000 colour-selected AGN from redshift $z$ = 0 to 7.5 using multiple data sets homogenized to identical cosmologies, intrinsic AGN spectra, and magnitude systems. Using this sample, we derive the AGN UV luminosity function from redshift $z$ = 0 to 7.5. The luminosity function has a double power-law form at all redshifts. The break magnitude M* shows a steep brightening from M* ∼ −24 at $z$ = 0.7 to M* ∼ −29 at $z$ = 6. The faint-end slope β significantly steepens from −1.9 at $z$ < 2.2 to −2.4 at $z$ ≃ 6. In spite of this steepening, the contribution of AGN to the hydrogen photoionization rate at $z$ ∼ 6 is subdominant (<3 per cent), although it can be non-negligible (∼10 per cent) if these luminosity functions hold down to M1450 = −18. Under reasonable assumptions, AGN can reionize He ii by redshift $z$ = 2.9. At low redshifts ($z$ < 0.5), AGN can produce about half of the hydrogen photoionization rate inferred from the statistics of H i absorption lines in the intergalactic medium. Our analysis also reveals important systematic errors in the data, which need to be addressed and incorporated in the AGN selection function in future in order to improve our results. We make various fitting functions, codes, and data publicly available.
Differences in spatial distribution between WHO 2016 low-grade glioma molecular subgroups
Authors: Wijnenga Maarten M J , van der Voort Sebastian R , French Pim J , Klein Stefan , Dubbink Hendrikus J , Dinjens Winand N M , Atmodimedjo Peggy N , de Groot Marius , Kros Johan M , Schouten Joost W , Dirven Clemens M F , Vincent Arnaud J P E , Smits Marion , van den Bent Martin J
Published: May 2019

Background

Several studies reported a correlation between anatomic location and genetic background of low-grade gliomas (LGGs). As such, tumor location may contribute to presurgical clinical decision-making. Our purpose was to visualize and compare the spatial distribution of different WHO 2016 gliomas, frequently aberrated single genes and DNA copy number alterations within subgroups, and groups of postoperative tumor volume.

Methods

Adult grade II glioma patients (WHO 2016 classified) diagnosed between 2003 and 2016 were included. Tumor volume and location were assessed with semi-automatic software. All volumes of interest were mapped to a standard reference brain. Location heatmaps were created for each WHO 2016 glioma subgroup, frequently aberrated single genes and copy numbers (CNVs), as well as heatmaps according to groups of postoperative tumor volume. Differences between subgroups were determined using voxelwise permutation testing.

Results

A total of 110 IDH mutated astrocytoma patients, 92 IDH mutated and 1p19q co-deleted oligodendroglioma patients, and 22 IDH wild-type astrocytoma patients were included. We identified small regions in which specific molecular subtypes occurred more frequently. IDH-mutated LGGs were more frequently located in the frontal lobes and IDH wild-type tumors more frequently in the basal ganglia of the right hemisphere. We found no localizations of significant difference for single genes/CNVs in subgroups, except for loss of 9p in oligodendrogliomas with a predilection for the left parietal lobes. More extensive resections in LGG were associated with frontal locations.

Conclusions

WHO low-grade glioma subgroups show differences in spatial distribution. Our data may contribute to presurgical clinical decision-making in LGG patients.