bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robots and Firms
Authors: Koch Michael , Manuylov Ilya , Smolka Marcel 
Published: January 2021

Abstract
We study the microeconomic implications of robot adoption using a rich panel data set of Spanish manufacturing firms over a 27-year period (1990–2016). We provide causal evidence on two central questions: (1) Which firm characteristics prompt firms to adopt robots? (2) What is the impact of robots on adopting firms relative to non-adopting firms? To address these questions, we look at our data through the lens of recent attempts in the literature to formalise the implications of robot technology. As for the first question, we establish robust evidence for positive selection, i.e., ex ante better performing firms (measured through output and labour productivity) are more likely to adopt robots. On the other hand, conditional on size, ex ante more skill-intensive firms are less likely to do so. As for the second question, we find that robot adoption generates substantial output gains in the vicinity of 20–25% within four years, reduces the labour cost share by 5–7% points, and leads to net job creation at a rate of 10%. These results are robust to controlling for non-random selection into robot adoption through a difference-in-differences approach combined with a propensity score reweighting estimator. To further validate these results, we also offer structural estimates of total factor productivity (TFP) where robot technology enters the (endogenous) productivity process of firms. The results demonstrate a positive causal effect of robots on productivity as well as a complementarity between robots and exporting in boosting productivity.
Military Statecraft and the Use of Multinational Exercises in World Politics
Authors: Wolfley Kyle J 
Published: January 2021

Abstract
Although multinational military exercises have become a common foreign policy tool over the last three decades, our understanding of their purpose and variation is limited. Why do major powers conduct multinational exercises, especially with non-allies, and why did exercises increase after the end of the Cold War? I argue that a rise in strategic uncertainty—when adversaries and allies become less obvious—led major powers to increase their use of “shaping” exercises: training events designed not to threaten or prepare to use force, but to change the characteristics of or relationship between militaries. Textual sentiment analysis and regressions of over a thousand multinational exercises from 1980 to 2016 reveal that major powers reacted to an increase in strategic uncertainty by using these types of exercises to manage ambiguous threats and partners. This study highlights why and how major powers implement diverse tools of military statecraft—that is, the use of military organizations to achieve foreign policy goals—to reduce the threat of violent non-state actors and undermine one another in a competitive international system.
The Different Faces of Public Opinion: Is the American Voter Tinted by Mode?
Authors: Shino Enrijeta , Martinez Michael D 
Published: February 2021

Abstract
Declining response rates and increasing costs of collecting public opinion survey data have led to an increasing usage of dual-mode surveys. Revisiting foundational theories of political knowledge, issue constraint, and issue voting, we gauge the theoretical implications this methodological change has in our understanding of the public opinion and voter behavior. We see different patterns in the 2012 and 2016 American National Election Studies and observe clear mode effects in an original dual-mode survey experiment of Florida registered voters. Overall, we find that web respondents appear to be more politically knowledgeable, ideologically constrained, and have greater correspondence between issue and vote preferences compared to face-to-face or phone respondents. Survey mode matters, even with a common sampling frame.
Animal Models of COVID-19. I. Comparative Virology and Disease Pathogenesis
Authors: Zeiss Caroline J , Compton Susan , Veenhuis Rebecca Terilli 
Published: January 2021

Abstract
The Coronavirus Disease 2019 (COVID-19) pandemic has fueled unprecedented development of animal models to understand disease pathogenesis, test therapeutics, and support vaccine development. Models previously developed to study severe acute respiratory syndrome coronavirus (SARS-CoV) have been rapidly deployed to study SARS-CoV-2. However, it has become clear that despite the common use of ACE2 as a receptor for both viruses, the host range of the 2 viruses does not entirely overlap. Distinct ACE2-interacting residues within the receptor binding domain of SARS-CoV and SARS-CoV-2, as well as species differences in additional proteases needed for activation and internalization of the virus, are likely sources of host differences between the 2 viruses. Spontaneous models include rhesus and cynomolgus macaques, African Green monkeys, hamsters, and ferrets. Viral shedding and transmission studies are more frequently reported in spontaneous models. Mice can be infected with SARS-CoV; however, mouse and rat ACE2 does not support SARS-CoV-2 infection. Murine models for COVID-19 are induced through genetic adaptation of SARS-CoV-2, creation of chimeric SARS-CoV and SARS-CoV-2 viruses, use of human ACE2 knock-in and transgenic mice, and viral transfection of wild-type mice with human ACE2. Core aspects of COVID-19 are faithfully reproduced across species and model. These include the acute nature and predominantly respiratory source of viral shedding, acute transient and nonfatal disease with a largely pulmonary phenotype, similar short-term immune responses, and age-enhanced disease. Severity of disease and tissue involvement (particularly brain) in transgenic mice varies by promoter. To date, these models have provided a remarkably consistent template on which to test therapeutics, understand immune responses, and test vaccine approaches. The role of comorbidity in disease severity and the range of severe organ-specific pathology in humans remains to be accurately modeled.
Excess risk bounds in robust empirical risk minimization
Authors: Mathieu Timothée , Minsker Stanislav 
Published: January 2021

AbstractThis paper investigates robust versions of the general empirical risk minimization algorithm, one of the core techniques underlying modern statistical methods. Success of the empirical risk minimization is based on the fact that for a ‘well-behaved’ stochastic process $\left \{ f(X), \ f\in \mathscr F\right \}$ indexed by a class of functions $f\in \mathscr F$, averages $\frac{1}{N}\sum _{j=1}^N f(X_j)$ evaluated over a sample $X_1,\ldots ,X_N$ of i.i.d. copies of $X$ provide good approximation to the expectations $\mathbb E f(X)$, uniformly over large classes $f\in \mathscr F$. However, this might no longer be true if the marginal distributions of the process are heavy tailed or if the sample contains outliers. We propose a version of empirical risk minimization based on the idea of replacing sample averages by robust proxies of the expectations and obtain high-confidence bounds for the excess risk of resulting estimators. In particular, we show that the excess risk of robust estimators can converge to $0$ at fast rates with respect to the sample size $N$, referring to the rates faster than $N^{-1/2}$. We discuss implications of the main results to the linear and logistic regression problems and evaluate the numerical performance of proposed methods on simulated and real data.
Uncertainty principle for communication compression in distributed and federated learning and the search for an optimal compressor
Authors: Safaryan Mher , Shulgin Egor , Richtárik Peter 
Published: January 2021

Abstract
In order to mitigate the high communication cost in distributed and federated learning, various vector compression schemes, such as quantization, sparsification and dithering, have become very popular. In designing a compression method, one aims to communicate as few bits as possible, which minimizes the cost per communication round, while at the same time attempting to impart as little distortion (variance) to the communicated messages as possible, which minimizes the adverse effect of the compression on the overall number of communication rounds. However, intuitively, these two goals are fundamentally in conflict: the more compression we allow, the more distorted the messages become. We formalize this intuition and prove an uncertainty principle for randomized compression operators, thus quantifying this limitation mathematically, and effectively providing asymptotically tight lower bounds on what might be achievable with communication compression. Motivated by these developments, we call for the search for the optimal compression operator. In an attempt to take a first step in this direction, we consider an unbiased compression method inspired by the Kashin representation of vectors, which we call Kashin compression (KC). In contrast to all previously proposed compression mechanisms, KC enjoys a dimension independent variance bound for which we derive an explicit formula even in the regime when only a few bits need to be communicate per each vector entry.
A robustness comparison of two market network models
Authors: Semenov D P , Koldanov A P , Koldanov P A , Pardalos P M 
Published: January 2021

AbstractTwo market network models are investigated. One of them is based on the classical Pearson correlation as the measure of association between stocks returns, whereas the second one is based on the sign similarity measure of association between stocks returns. We study the uncertainty of identification procedures for the following market network characteristics: distribution of weights of edges, vertex degree distribution in the market graph (MG), cliques and independent sets in the MG and the vertex degree distribution of the maximum spanning tree. We define the true network characteristics, the losses from the error of its identification by observations and the uncertainty of identification procedures as the expected value of losses. We use an elliptically contoured distribution as a model of the multivariate stocks returns distribution. It is shown that identification of statistical procedures based on the sign similarity are statistically robust in contrast to the procedures based on the classical Pearson correlation.
Dose–response and functional role of whey permeate as a source of lactose and milk oligosaccharides on intestinal health and growth of nursery pigs
Authors: Jang Ki Beom , Purvis Jerry M , Kim Sung W 
Published: January 2021

Abstract
Two experiments were conducted to evaluate dose–response and supplemental effects of whey permeate on growth performance and intestinal health of nursery pigs. In experiment (exp.) 1, 1,080 pigs weaned at 6.24 kg body weight (BW) were allotted to five treatments (eight pens/treatment) with increasing levels of whey permeate in three phases (from 10% to 30%, 3% to 23%, and 0% to 9% for phase 1, 2, and 3, respectively) fed until 11 kg BW and then fed a common phase 4 diet (0% whey permeate) until 25 kg BW in a 48-d feeding trial. Feed intake and BW were measured at the end of each phase. In exp. 2, 1,200 nursery pigs at 7.50 kg BW were allotted to six treatments (10 pens/treatment) with increasing levels of whey permeate from 0% to 18.75% fed until 11 kg BW. Feed intake and BW were measured during 11 d. Six pigs per treatment (1 per pens) were euthanized to collect the jejunum to evaluate tumor necrosis factor-alpha, interleukin-8 (IL-8), transforming growth factor-beta 1, mucin 2, histomorphology, digestive enzyme activity, crypt cell proliferation rate, and jejunal mucosa-associated microbiota. Data were analyzed using contrasts in the MIXED procedure and a broken-line analysis using the NLIN procedure of SAS. In exp. 1, increasing whey permeate had a quadratic effect (P &lt; 0.05) on feed efficiency (G:F; maximum: 1.35 at 18.3%) in phase 1. Increasing whey permeate linearly increased (P &lt; 0.05) average daily gain (ADG; 292 to 327 g/d) and G:F (0.96 to 1.04) of pigs in phase 2. In exp. 2, increasing whey permeate linearly increased (P &lt; 0.05) ADG (349 to 414 g/d) and G:F (0.78 to 0.85) and linearly increased (P &lt; 0.05) crypt cell proliferation rate (27.8% to 37.0%). The breakpoint from a broken-line analysis was obtained at 13.6% whey permeate for maximal G:F. Increasing whey permeate tended to change IL-8 (quadratic, P = 0.052; maximum: 223 pg/mg at 10.9%), to decrease Firmicutes:Bacteroidetes (P = 0.073, 1.59 to 1.13), to increase (P = 0.089) Bifidobacteriaceae (0.73% to 1.11%), and to decrease Enterobacteriaceae (P = 0.091, 1.04% to 0.52%) and Streptococcaceae (P = 0.094, 1.50% to 0.71%) in the jejunal mucosa. In conclusion, dietary inclusion of whey permeate increased the growth of nursery pigs from 7 to 11 kg BW. Pigs grew most efficiently with 13.6% whey permeate. Improvement in growth performance is partly attributed to stimulating intestinal immune response and enterocyte proliferation with positive changes in jejunal mucosa-associated microbiota in nursery pigs.
Geographical stratification of urban green areas in European cities
Authors: Picard Pierre M , Tran Huyen T T 
Published: January 2021

Abstract
This article studies the provision of urban green areas in cities where residents have preferences for the size of and access to those areas. At the optimum, the number of urban green spaces is a nonmonotone function of distance to the city center, while the sizes and distances to other urban green areas increase as one moves to the urban fringe. This article empirically investigates those properties for the 300 largest European cities by using the Global Monitoring Environment Services Urban Atlas database (European Environmental Agency). The empirical analysis confirms the nonmonotone relationship between the number of urban green spaces and the distance to the city center. The distance between two parks also increases as one moves toward the urban fringe.
A low CO2-responsive mutant of Setaria viridis reveals that reduced carbonic anhydrase limits C4 photosynthesis
Authors: Chatterjee Jolly , Coe Robert A , Acebron Kelvin , Thakur Vivek , Yennamalli Ragothaman M , Danila Florence , Lin Hsiang-Chun , Balahadia Christian Paolo , Bagunu Efren , Padhma Preiya P O S , Bala Soumi , Yin Xiaojia , Rizal Govinda , Dionora Jacqueline , Furbank Robert T , von Caemmerer Susanne , Quick William Paul 
Published: January 2021

Abstract
In C4 species, β-carbonic anhydrase (CA), localized to the cytosol of the mesophyll cells, accelerates the interconversion of CO2 to HCO3–, the substrate used by phosphoenolpyruvate carboxylase (PEPC) in the first step of C4 photosynthesis. Here we describe the identification and characterization of low CO2-responsive mutant 1 (lcr1) isolated from an N-nitroso-N-methylurea- (NMU) treated Setaria viridis mutant population. Forward genetic investigation revealed that the mutated gene Sevir.5G247800 of lcr1 possessed a single nucleotide transition from cytosine to thymine in a β-CA gene causing an amino acid change from leucine to phenylalanine. This resulted in severe reduction in growth and photosynthesis in the mutant. Both the CO2 compensation point and carbon isotope discrimination values of the mutant were significantly increased. Growth of the mutants was stunted when grown under ambient pCO2 but recovered at elevated pCO2. Further bioinformatics analyses revealed that the mutation has led to functional changes in one of the conserved residues of the protein, situated near the catalytic site. CA transcript accumulation in the mutant was 80% lower, CA protein accumulation 30% lower, and CA activity ~98% lower compared with the wild type. Changes in the abundance of other primary C4 pathway enzymes were observed; accumulation of PEPC protein was significantly increased and accumulation of malate dehydrogenase and malic enzyme decreased. The reduction of CA protein activity and abundance in lcr1 restricts the supply of bicarbonate to PEPC, limiting C4 photosynthesis and growth. This study establishes Sevir.5G247800 as the major CA allele in Setaria for C4 photosynthesis and provides important insights into the function of CA in C4 photosynthesis that would be required to generate a rice plant with a functional C4 biochemical pathway.
Wedlock or Wed-Lockup? A Case for Abolishing Restitution of Conjugal Rights in India
Authors: Uma Saumya 
Published: January 2021

Abstract
Colonialism in India consisted of a “civilizing mission” when the British rulers sought to initiate reforms in India, by projecting themselves to be the forerunners of modernity. Ironically, restitution of conjugal rights (RCR) runs contrary to any claims of modernity. Through an RCR, an unwilling spouse could be directed by the coercive machinery of the law to cohabit with his/her spouse, in recognition of the right of married persons to conjugality and consortium. Although couched in gender neutral terms, the remedy had and continues to have grave ramifications for women. This was applied by British judges to family law cases in India in the 1800s, and incorporated in family law statutes in post-independent India. RCR remains in force and is a legal remedy sought in the Indian courts till date, although it was abolished in England in 1970. This article critically examines RCR through historical, legal, feminist and comparative law perspectives. It analyses the impact of the English remedy on the norms of marriage and family in India, which are sites of oppression of, violence against and subordination of women. It argues for the repeal of RCR from the Indian statute books as it undermines bodily integrity and sexual autonomy of women in intimate relationships, and is incongruent with constitutional principles and India’s international human rights obligations.
Searching for wide-orbit gravitational instability protoplanets with ALMA in the dust continuum
Authors: Humphries J , Hall C , Haworth T J , Nayakshin S 
Published: January 2021

ABSTRACT
Searches for young gas giant planets at wide separations have so far focused on techniques appropriate for compact (Jupiter-sized) planets. Here, we point out that protoplanets born through gravitational instability (GI) may remain in an initial pre-collapse phase for as long as the first 105–107 yr after formation. These objects are hundreds of times larger than Jupiter and their atmospheres are too cold (T ∼ tens of K) to emit in the near-infrared or Hα via accretion shocks. However, it is possible that their dust emission can be detected with Atacama Large Millimeter/submillimeter Array (ALMA), even around Classes I and II protoplanetary discs. In this paper, we produce synthetic observations of these protoplanets. We find that making a detection in a disc at 140 pc would require a few hundred minutes of ALMA band 6 observation time. Protoplanets with masses of 3–5 MJ have the highest chance of being detected; less massive objects require unreasonably long observation times (1000 min), while more massive ones collapse into giant planets before 105 yr. We propose that high-resolution surveys of young (105–106 yr), massive and face on discs offer the best chance for observing protoplanets. Such a detection would help to place constraints on the protoplanet mass spectrum, explain the turnover in the occurrence frequency of gas giants with system metallicity and constrain the prevalence of GI as a planet formation mechanism. Consistent lack of detection would be evidence against GI as a common planet formation mechanism.
Music Use in Adult Patients with Sickle Cell Disease: A Pilot Survey Study
Authors: Rodgers-Melnick Samuel N , Gam Kristina , Debanne Sara , Little Jane A 
Published: January 2021

Abstract
Sickle cell disease (SCD) is a group of genetic disorders primarily affecting individuals of African descent. Adults with SCD experience both acute and chronic pain. Data on music preferences, resources, and music-based pain strategies of adults with SCD are needed to tailor future music therapy interventions to the unique needs of adults with SCD. The purpose of this study was to (1) gather descriptive data related to music use in adults with SCD and (2) explore associations between participants’ music use, pain interference, and perceived helpfulness of music for reducing pain. In total, 100 adults with SCD participated in this survey during outpatient clinic visits. Results indicate a population that: (1) faces significant challenges related to pain interference (M = 61.13, SE = 0.76); (2) perceives music as being helpful for managing challenges, including mood (57%), sleep (48%), stress (47%), and pain (37%); (3) purposefully engages in music listening to manage pain (74%); and (4) would be interested in participating in music therapy services in inpatient (88%) and outpatient (81%) settings. Participants selected songs in genres, such as Hip-Hop/Rap and R&B/Soul, that contrast with previously reported characteristics of music for pain management. There was a moderate positive correlation (rs = 0.516, p &lt; .001) between the number of strategies used alongside music and the perceived helpfulness of music for reducing pain. Findings inform the clinical use of music therapy and support future music therapy research with this population to address quality of life.
Interplay of folded domains and the disordered low-complexity domain in mediating hnRNPA1 phase separation
Authors: Martin Erik W , Thomasen F Emil , Milkovic Nicole M , Cuneo Matthew J , Grace Christy R , Nourse Amanda , Lindorff-Larsen Kresten , Mittag Tanja 
Published: January 2021

AbstractLiquid–liquid phase separation underlies the membrane-less compartmentalization of cells. Intrinsically disordered low-complexity domains (LCDs) often mediate phase separation, but how their phase behavior is modulated by folded domains is incompletely understood. Here, we interrogate the interplay between folded and disordered domains of the RNA-binding protein hnRNPA1. The LCD of hnRNPA1 is sufficient for mediating phase separation in vitro. However, we show that the folded RRM domains and a folded solubility-tag modify the phase behavior, even in the absence of RNA. Notably, the presence of the folded domains reverses the salt dependence of the driving force for phase separation relative to the LCD alone. Small-angle X-ray scattering experiments and coarse-grained MD simulations show that the LCD interacts transiently with the RRMs and/or the solubility-tag in a salt-sensitive manner, providing a mechanistic explanation for the observed salt-dependent phase separation. These data point to two effects from the folded domains: (i) electrostatically-mediated interactions that compact hnRNPA1 and contribute to phase separation and (ii) increased solubility at higher ionic strengths mediated by the folded domains. The interplay between disordered and folded domains can modify the dependence of phase behavior on solution conditions and can obscure signatures of physicochemical interactions underlying phase separation.