bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced ‘Border effects’, Free Trade Agreements and international trade
Authors: Franco‐Bedoya Sebastian , Frohm Erik
Published: October 2021

This paper studies the impact of ‘border effects’ and the implementation of Free Trade Agreements (FTAs) on international trade in manufacturing goods. We take advantage of the time dimension in a panel setting to capture the rise of trade in final goods and intermediate inputs that are a distinguishing feature of Global Value Chains (GVCs). Our results suggest that reduced border effects account for the bulk of the increase in international manufacturing trade. The cost of a national border is estimated to have fallen by around 4.3% per year for trade in final goods and 2.8% for trade in intermediate inputs. Moreover, we show that it is important to control for different border effects for final goods and intermediate inputs when estimating the trade impact of FTAs in gravity equations. With this enhancement, our results suggest that FTAs increase trade in final goods by 52% after ten years, with no statistically significant difference for trade in intermediate inputs. We also find evidence that FTAs that more comprehensive FTAs like the European Union have a greater trade effect than the average FTA.
Mas‐related G protein‐coupled receptor D is involved in modulation of murine gastrointestinal motility
Authors: Xu Min , Li Jia , Zhang Zhudi , Liu Lin , Wan Fengyi , Tang Zongxiang , Lan Lei
Published: October 2021

New Findings

What is the central question of this study?

The physiological function of Mas‐related G protein‐coupled receptor D (MrgprD) in gastrointestinal motility is unknown. The aim of this study was to assess the effects of MrgprD and its receptor agonists on murine gastrointestinal motility.

What is the main finding and its importance?

Mrgprd deficiency improved murine gastrointestinal motility in vivo but had no effects on the spontaneous contractions of murine intestinal rings ex vivo. Systemic administration of the MrgprD ligand, either β‐alanine or alamandine, delayed gastrointestinal transit in vivo and attenuated the spontaneous contractions of isolated intestinal rings ex vivo.

Mas‐related G protein‐coupled receptor D (MrgprD) was first identified in sensory neurons of mouse dorsal root ganglion and has been demonstrated to be involved in sensations of pain and itch. Although expression of MrgprD has recently been found in the gastrointestinal (GI) tract, its physiological role in GI motility is unknown. To address this question, we used Mrgprd knockout (Mrgprd−/−) mice and MrgprD agonists to examine the effects of Mrgprd gene deletion and MrgprD signalling activation, respectively, on murine intestinal motility, both in vivo and ex vivo. We observed that the deletion of Mrgprd accelerated the transmission of charcoal through the mouse GI tract. But Mrgprd deficiency did not affect the mean amplitudes and frequencies of spontaneous contractions in ileum ex vivo. Colonic motor complexes in the proximal and the distal colon were recorded from wild‐type and Mrgprd−/− mice, but their control frequencies were not different. Moreover, in wild‐type mice, systemic administration of an MrgprD agonist, either β‐alanine or alamandine, delayed GI transit in vivo and suppressed spontaneous contractions in the ileum and colonic motor complexes in the colon ex vivo. Our results suggest that MrgprD and its agonist are involved in the modulation of GI motility in mice.
The association between pain‐induced autonomic reactivity and descending pain control is mediated by the periaqueductal grey
Authors: Makovac Elena , Venezia Alessandra , Hohenschurz‐Schmidt David , Dipasquale Ottavia , Jackson Jade B. , Medina Sonia , O'Daly Owen , Williams Steve C. R. , McMahon Stephen B. , Howard Matthew A.
Published: October 2021

There is a strict interaction between the autonomic nervous system (ANS) and pain, which might involve descending pain modulatory mechanisms. The periaqueductal grey (PAG) is involved both in descending pain modulation and ANS, but its role in mediating this relationship has not yet been explored. Here, we sought to determine brain regions mediating ANS and descending pain control associations. Thirty participants underwent conditioned pain modulation (CPM) assessments, in which they rated painful pressure stimuli applied to their thumbnail, either alone or with a painful cold contralateral stimulation. Differences in pain ratings between ‘pressure‐only’ and ‘pressure + cold’ stimuli provided a measure of descending pain control. In 18 of the 30 participants, structural scans and two functional MRI assessments, one pain‐free and one during cold‐pain were acquired. Heart rate variability (HRV) was simultaneously recorded. Normalised low‐frequency HRV (LF‐HRVnu) and the CPM score were negatively correlated; individuals with higher LF‐HRVnu during pain reported reductions in pain during CPM. PAG‐ventro‐medial prefrontal cortex (vmPFC) and PAG‐rostral ventromedial medulla (RVM) functional connectivity correlated negatively with the CPM. Importantly, PAG‐vmPFC functional connectivity mediated the strength of the LF‐HRVnu‐CPM association. CPM response magnitude was also negatively correlated with vmPFC GM volume. Our multi‐modal approach, using behavioural, physiological and MRI measures, provides important new evidence of interactions between ANS and descending pain mechanisms. ANS dysregulation and dysfunctional descending pain modulation are characteristics of chronic pain. We suggest that further investigation of body‐brain interactions in chronic pain patients may catalyse the development of new treatments.

image

Key points

Heart rate variability (HRV) is associated with descending pain modulation as measured by the conditioned pain modulation protocol (CPM).

There is an association between CPM scores and the functional connectivity between the periaqueductal grey (PAG) and ventro‐medial prefrontal cortex (vmPFC).

CPM scores are also associated with vmPFC grey matter volume.

The strength of functional connectivity between the PAG and vmPFC mediates the association between HRV and CPM.

Our data provide new evidence of interactions between the autonomic nervous system and descending pain mechanisms.
Desigualdad socioeconómica y segregación residencial en Argentina. Niveles y tendencias recientes (1991-2001-2010)
Authors: Rodríguez Gonzalo Martín
Published: October 2021

Este trabajo se propone conocer los niveles y tendencias de la segregación residencial socioeconómica (SRS) en Argentina, a lo largo de dos décadas, comprendidas entre 1991-2001 (década neoliberal) y 2001-2010 (década redistributiva), que aproximadamente coinciden con dos períodos de signo político y económico distintos. Se propone como hipótesis que existe una correlación entre la desigualdad socioeconómica y la SRS: esta aumenta en períodos de concentración de la riqueza y disminuye en período de signo contrario. El estudio abarca 783 ciudades argentinas de todos los tamaños y mide el nivel de SRS en cada una de ellas, así como la distribución del ingreso en un conjunto más reducido de 34 ciudades. Se aplica una metodología innovadora para controlar el efecto distorsivo del PUEM sobre los índices de segregación. Los resultados obtenidos muestran evidencias parcialmente consistentes con la hipótesis. Por un lado, existe una correlación positiva y significativa entre la SRS y la desigualdad socioeconómica. Por otro lado, la SRS disminuyó durante la década redistributiva, aunque también se redujo levemente en la década neoliberal previa.
Fraccionamientos cerrados en los entornos segregados del Área Metropolitana de Guadalajara y sus experiencias espaciales
Authors: Sevilla Villalobos Salvador
Published: October 2021

La globalización en los contextos latinoamericanos ha convertido a los fraccionamientos cerrados en uno de los negocios vinculados a la urbanización que mayor grado de rentabilidad tiene, al posicionar una red de residencias fortificadas particulares a partir de su adaptabilidad en los contextos históricos y socioculturales en los que se localizan. El avanceen los estudios de estos entornos, sin embargo, limita a concebirlos como entidades que mantienen en su interior individuos en estado de enclaustramiento, ajenos del mundo público. Con la intención de evidenciar su existencia, particularidad como nuevo agente de la urbe y el grado de participación, el presente texto expone los comportamientos espaciales cotidianos de la población de uno de estos desarrollos inmobiliarios ubicados en  la zona marginada del Área Metropolitana de Guadalajara, el fraccionamiento Jardines de San Rafael, al centrarse en explorar las relaciones multiescalares que influyen en que estos sean conformados.
Urban Planning and Socioenvironmental Disasters: The Myth of Urban Expansion in Blumenau/SC
Authors: Ludwig Leandro , Mattedi Marcos Antonio , Avila Maria Roseli
Published: October 2021

This text aims to address the relationship between social-environmental disasters and the Urban Planning in the definition of urban expansion strategies from Blumenau to the North Region of the city. It is argued that the city was modified from two processes: 1) The effects of urban planning (generated by the idea of an ideal city); 2) the disaster effects (generated by the actual city). From these two processes, this text evidences that the strategies of the Urban and Regional Planning of Blumenau constitute social markers of the segregating effect of disasters. In order to develop this argument the text is structured in three main sections: 1) The formation and urban development of Blumenau; 2) disasters and the myth of urban expansion to the Northern Region; 3) the relationship between disasters and the limits of Urban Planning.
The effect of broadband elicitor laterality on psychoacoustic gain reduction across signal frequency
Authors: Salloom William B. , Strickland Elizabeth A.
Published: October 2021

There are psychoacoustic methods thought to measure gain reduction, which may be from the medial olivocochlear reflex (MOCR), a bilateral feedback loop that adjusts cochlear gain. Although studies have used ipsilateral and contralateral elicitors and have examined strength at different signal frequencies, these factors have not been examined within a single study. Therefore, basic questions about gain reduction, such as the relative strength of ipsilateral vs contralateral elicitation and the relative strength across signal frequency, are not known. In the current study, gain reduction from ipsilateral, contralateral, and bilateral elicitors was measured at 1-, 2-, and 4-kHz signal frequencies using forward masking paradigms at a range of elicitor levels in a repeated measures design. Ipsilateral and bilateral strengths were similar and significantly larger than contralateral strength across signal frequencies. Growth of gain reduction with precursor level tended to differ with signal frequency, although not significantly. Data from previous studies are considered in light of the results of this study. Behavioral results are also considered relative to anatomical and physiological data on the MOCR. These results indicate that, in humans, cochlear gain reduction is broad across frequencies and is robust for ipsilateral and bilateral elicitation but small for contralateral elicitation.
Upwelling Intensification As Part of the Pliocene-Pleistocene Climate Transition
Authors: Marlow Jeremy R. , Lange Carina B. , Wefer Gerold , Rosell-Melé Antoni
Published: October 2021

A deep-sea sediment core underlying the Benguela upwelling system off southwest Africa provides a continuous time series of sea surface temperature (SST) for the past 4.5 million years. Our results indicate that temperatures in the region have declined by about 10°C since 3.2 million years ago. Records of paleoproductivity suggest that this cooling was associated with an increase in wind-driven upwelling tied to a shift from relatively stable global warmth during the mid-Pliocene to the high-amplitude glacial-interglacial cycles of the late Quaternary. These observations imply that Atlantic Ocean surface water circulation was radically different during the mid-Pliocene.
With COVID-19, modeling takes on life and death importance
Authors: Enserink Martin , Kupferschmidt Kai
Published: October 2021

Epidemic simulations shape national responses.
Muscle repair after physiological damage relies on nuclear migration for cellular reconstruction
Authors: Roman William , Pinheiro Helena , Pimentel Mafalda R. , Segalés Jessica , Oliveira Luis M. , García-Domínguez Esther , Gómez-Cabrera Mari Carmen , Serrano Antonio L. , Gomes Edgar R. , Muñoz-Cánoves Pura
Published: October 2021

Muscle repair without stem cells

Skeletal muscle is a mechanical organ that endures cellular damage after contraction. Lesions caused by external injury can be repaired by muscle stem cells, which fuse with injured cells or create entirely new myofibers. Roman
et al
. describe a cell-autonomous repair process that is independent of muscle stem cells (see the Perspective by McNally and Demonbreun). After localized damage, myonuclei migrate to injury sites and locally deliver messenger RNA for cellular reconstruction. This myofiber self-repair represents a model for understanding the restoration of muscle architecture in health and disease. —BAP
Mitochondrial translation is required for sustained killing by cytotoxic T cells
Authors: Lisci Miriam , Barton Philippa R. , Randzavola Lyra O. , Ma Claire Y. , Marchingo Julia M. , Cantrell Doreen A. , Paupe Vincent , Prudent Julien , Stinchcombe Jane C. , Griffiths Gillian M.
Published: October 2021

Mitochondria drive CTLs’ killer instinct

Cytotoxic T lymphocytes (CTLs) can terminate both virally infected cells and cancer cells by secreting cytolytic proteins such as perforin and granzyme B. CTLs are particularly effective because they can sequentially kill multiple targets in a process called serial killing. Lisci
et al
. have identified mitochondria as important regulators of CTL killing. Mice lacking the deubiquitinase USP30 have CTLs acutely depleted of mitochondria, and these cells have reduced killing ability but normal motility, signaling, and secretion. Surprisingly, the mitochondria’s metabolic functions were not required for this process. Rather, mitochondrial translation proved indispensable for CTL cytolytic protein synthesis and sustained CTL killing. —STS
The corporate shadow in democratic policing
Authors: Joh Elizabeth E.
Published: October 2021

Technology companies can elude accountability
Policing social unrest and collective violence
Authors: Hinton Elizabeth
Published: October 2021

Policies too often ignore root socioeconomic causes of “riots”
Response to Comment on “Reintroduction of the archaic variant of
NOVA1
in cortical organoids alters neurodevelopment”
Authors: Herai Roberto H. , Szeto Ryan A. , Trujillo Cleber A. , Muotri Alysson R.
Published: October 2021

Maricic
et al
. performed an undisclosed in silico–only whole-exome sequencing analysis of our data and found genomic alterations previously undetected in some clones. Some of the predicted alterations, if true, could change the original genotype of the clones. We failed to experimentally validate all but one of these genomic alterations, which did not affect our previous results or data interpretation.
Assessing mass incarceration’s effects on families
Authors: Lee Hedwig , Wildeman Christopher
Published: October 2021

In this Review, we assess how mass incarceration, a monumental American policy experiment, has affected families over the past five decades. We reach four conclusions. First, family member incarceration is now common for American families. Second, individuals who will eventually have a family member incarcerated are worse off than those who never will, even before the incarceration takes place. Third, family member incarceration has negative effects on families above and beyond these preexisting disadvantages. And finally, policy interventions that address the precursors to family member incarceration and seek to minimize family member incarceration would best enhance family well-being. If the goal is to help all American families thrive, then the importance of simultaneous changes in social and criminal justice policy cannot be overstated.
Exclusion and exploitation: The incarceration of Black Americans from slavery to the present
Authors: Muller Christopher
Published: October 2021

Understanding long-run patterns in the incarceration of Black Americans requires integrating the study of racial inequality with the study of political economy. I offer a parsimonious framework describing how the Black incarceration rate has been affected by the dynamics of exploitation and exclusion over time and across space. This framework helps to explain otherwise puzzling facts, like why the Black incarceration rate was lower in the South than in the North for much of the 20th century, why it was lowest in the South’s cotton belt, and why it began to tick upward when it did. It also enables us to better understand recent changes in racial and class inequality in incarceration in the United States.
The predatory dimensions of criminal justice
Authors: Page Joshua , Soss Joe
Published: October 2021

Over the past 35 years, public and private actors have turned US criminal justice institutions into a vast network of revenue-generating operations. Today, practices such as fines, fees, forfeitures, prison charges, and bail premiums transfer billions of dollars from oppressed communities to governments and corporations. Guided by scholarship on racial capitalism, we argue that to understand how and why criminal justice operates as it does today, one must attend to its predatory dimensions. Analytically and politically, the concept of predation connects diverse forms of criminal legal takings to one another, to the extractive regimes of earlier eras, and to contemporary businesses that financially exploit subjugated communities. Analyses that focus on predatory relations encourage a reconsideration of some dominant understandings in the study of criminal justice today.
Mechanism of siRNA production by a plant Dicer-RNA complex in dicing-competent conformation
Authors: Wang Qian , Xue Yan , Zhang Laixing , Zhong Zhenhui , Feng Suhua , Wang Changshi , Xiao Lifan , Yang Zhenlin , Harris C. Jake , Wu Zhe , Zhai Jixian , Yang Maojun , Li Sisi , Jacobsen Steven E. , Du Jiamu
Published: October 2021

Ready to dice

In the biogenesis of small RNAs, the Dicer family endonucleases act as a molecular ruler to cut the substrate RNA into defined lengths. Wang
et al
. report a structure of the dicing-competent state of plant DICER LIKE PROTEIN 3 (DCL3) in complex with a pre–small interfering RNA (pre-siRNA). Toward one end of the pre-siRNA, DCL3 uses a positively charged pocket and an aromatic cap to specifically recognize the 5′-phosphorylated adenosine of the guide strand and the 3′ overhang of the complementary strand, respectively. On the other end, the paired ribonuclease III domains of DCL3 cut both strands of the RNA, determining the precise length of the product small RNA. —DJ
Physicians’ flawed heuristics in the delivery room
Authors: Li Meng , Colby Helen
Published: October 2021

Delivery complications can influence later decision-making
Toward a holistic model of Alzheimer’s
How Not to Study a Disease: The Story of Alzheimer’s
Karl Herrup
MIT Press, 2021. 272 pp.
Authors: Spires-Jones Tara
Published: October 2021

An overemphasis on amyloid has stymied progress on the disease, alleges a neuroscientist
Gulf Stream and Kuroshio synchronization
Authors: Cessi Paola
Published: October 2021

The mid-latitude jet stream ties together the two major western boundary currents
mRNA vaccines induce durable immune memory to SARS-CoV-2 and variants of concern
Authors: Goel Rishi R. , Painter Mark M. , Apostolidis Sokratis A. , Mathew Divij , Meng Wenzhao , Rosenfeld Aaron M. , Lundgreen Kendall A. , Reynaldi Arnold , Khoury David S. , Pattekar Ajinkya , Gouma Sigrid , Kuri-Cervantes Leticia , Hicks Philip , Dysinger Sarah , Hicks Amanda , Sharma Harsh , Herring Sarah , Korte Scott , Baxter Amy E. , Oldridge Derek A. , Giles Josephine R. , Weirick Madison E. , McAllister Christopher M. , Awofolaju Moses , Tanenbaum Nicole , Drapeau Elizabeth M. , Dougherty Jeanette , Long Sherea , D’Andrea Kurt , Hamilton Jacob T. , McLaughlin Maura , Williams Justine C. , Adamski Sharon , Kuthuru Oliva ,   The UPenn COVID Processing Unit‡, Frank Ian , Betts Michael R. , Vella Laura A. , Grifoni Alba , Weiskopf Daniela , Sette Alessandro , Hensley Scott E. , Davenport Miles P. , Bates Paul , Luning Prak Eline T. , Greenplate Allison R. , Wherry E. John
Published: October 2021

Immune memory after vaccination

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has proven highly effective at preventing severe COVID-19. However, the evolution of viral variants, and waning antibody levels over time, raise questions regarding the longevity of vaccine-induced immune protection. Goel
et al
. examined B and T lymphocyte responses in individuals who received SARS-CoV-2 messenger RNA vaccines. They performed a 6-month longitudinal study of individuals who never had SARS-CoV-2 infection compared with people who had recovered from SARS-CoV-2. Humoral and cellular immune memory was observed in vaccinated individuals, as were functional immune responses against the Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2) viral variants. Analysis of T cell activity suggested that robust cellular immune memory may prevent hospitalization by limiting the development of severe disease. —PNK
Not all stress is bad for your heart
Authors: Jain Rajan , Epstein Jonathan A.
Published: October 2021

Shear stress forces instruct valve formation during cardiac development
Resealing and rebuilding injured muscle
Authors: McNally Elizabeth M. , Demonbreun Alexis R.
Published: October 2021

Reconstructing an injured muscle involves nuclear and mitochondrial contributions
In Science Journals
Authors: Stern Peter , Yeston Jake , Maroso Mattia , Osborne Ian S. , Smith Keith T. , Purnell Beverly A. , Turney Kristin , Rai Tage S. , Scanlon Seth Thomas , Suleymanov Yury , Vignieri Sacha , Smith H. Jesse , Williams Ifor , Wong Wei , Ray L. Bryan
Published: October 2021

Highlights from the
Science
family of journals
The sniff test
Authors: Smith Peter Andrey
Published: October 2021

Courtroom testimony about dogs detecting dead bodies keeps sending people to prison—even without physical evidence. Critics say the science is lacking
Massive road project threatens New Guinea’s biodiversity
Authors: Rochmyaningsih Dyna
Published: October 2021

The 4000-kilometer Trans-Papua Highway could turn the island’s western half into an “El Dorado for investors”
USDA revokes license of leading chinchilla supplier
Authors: Wadman Meredith
Published: October 2021

Hearing researchers may be left scrambling for animals
China embraces global biodiversity push—cautiously
Authors: Normile Dennis
Published: October 2021

Xi’s silence on 30% set-aside target disappoints advocates
Naive human B cells engage the receptor binding domain of SARS-CoV-2, variants of concern, and related sarbecoviruses
Authors: Feldman Jared , Bals Julia , Altomare Clara G. , St. Denis Kerri , Lam Evan C. , Hauser Blake M. , Ronsard Larance , Sangesland Maya , Moreno Thalia Bracamonte , Okonkwo Vintus , Hartojo Nathania , Balazs Alejandro B. , Bajic Goran , Lingwood Daniel , Schmidt Aaron G.
Published: October 2021

Naive antibodies targeting the SARS-CoV-2 receptor binding domain can be isolated from SARS-CoV-2 seronegative individuals.
Papers of note in
Nature
547
(7661)
Authors: VanHook Annalisa M.
Published: October 2021

This week’s articles highlight progress in predicting T cell receptor specificity; an evolutionarily ancient form of antiviral defense; a mechanism of chemotherapy-induced cell death; metabolic rewiring in cancer cells; and structural insights into activation of a GPCR and of a mechanosensitive ion channel.
Paper of note in
Science Translational Medicine
9
(397)
Authors: Ferrarelli Leslie K.
Published: October 2021

This week’s article describes how chemotherapy unintentionally enhances the dissemination of cancer cells into the circulation.
New connections: Amyloid-β, calcium, and the synapse
Authors: Ferrarelli Leslie K.
Published: October 2021

Insight into how amyloid-β impairs synaptic function reveals potential therapeutic targets for patients with Alzheimer’s disease.
Lung epithelial and endothelial damage, loss of tissue repair, inhibition of fibrinolysis, and cellular senescence in fatal COVID-19
Authors: D’Agnillo Felice , Walters Kathie-Anne , Xiao Yongli , Sheng Zong-Mei , Scherler Kelsey , Park Jaekeun , Gygli Sebastian , Rosas Luz Angela , Sadtler Kaitlyn , Kalish Heather , Blatti Charles A. , Zhu Ruoqing , Gatzke Lisa , Bushell Colleen , Memoli Matthew J. , O’Day Steven J. , Fischer Trevan D. , Hammond Terese C. , Lee Raymond C. , Cash J. Christian , Powers Matthew E. , O’Keefe Grant E. , Butnor Kelly J. , Rapkiewicz Amy V. , Travis William D. , Layne Scott P. , Kash John C. , Taubenberger Jeffery K.
Published: October 2021

Lung epithelial and endothelial cell damage and defective lung tissue repair contribute to fatal COVID-19.
Causal impact of social care, public health and healthcare expenditure on mortality in England: cross-sectional evidence for 2013/2014
Authors: Martin Stephen , Longo Francesco , Lomas James , Claxton Karl
Published: October 2021

Objectives

The first objective is to estimate the joint impact of social care, public health and healthcare expenditure on mortality in England. The second objective is to use these results to estimate the impact of spending constraints in 2010/2011–2014/2015 on total mortality.

Methods

The impact of social care, healthcare and public health expenditure on mortality is analysed by applying the two-stage least squares method to local authority data for 2013/2014. Next, we compare the growth in healthcare and social care expenditure pre-2010 and post-2010. We use the difference between these growth rates and the responsiveness of mortality to changes in expenditure taken from the 2013/2014 cross-sectional analysis to estimate the additional mortality generated by post-2010 spending constraints.

Results

Our most conservative results suggest that (1) a 1% increase in healthcare expenditure reduces mortality by 0.532%; (2) a 1% increase in social care expenditure reduces mortality by 0.336%; and (3) a 1% increase in local public health spending reduces mortality by 0.019%. Using the first two of these elasticities and data on the change in spending growth between 2001/2002–2009/2010 and 2010/2011–2014/2015, we find that there were 57 550 (CI 3075 to 111 955) more deaths in the latter period than would have been observed had spending growth during this period matched that in 2001/2002–2009/2010.

Conclusions

All three forms of public healthcare-related expenditure save lives and there is evidence that additional social care expenditure is more than twice as productive as additional healthcare expenditure. Our results are consistent with the hypothesis that the slowdown in the rate of improvement in life expectancy in England and Wales since 2010 is attributable to spending constraints in the healthcare and social care sectors.
Recommended conventions for reporting results from direct dark matter searches
Authors: Baxter D. , Bloch I. M. , Bodnia E. , Chen X. , Conrad J. , Di Gangi P. , Dobson J. E. Y. , Durnford D. , Haselschwardt S. J. , Kaboth A. , Lang R. F. , Lin Q. , Lippincott W. H. , Liu J. , Manalaysay A. , McCabe C. , Morå K. D. , Naim D. , Neilson R. , Olcina I. , Piro M. -C. , Selvi M. , von Krosigk B. , Westerdale S. , Yang Y. , Zhou N.
Published: October 2021

The field of dark matter detection is a highly visible and highly competitive one. In this paper, we propose recommendations for presenting dark matter direct detection results particularly suited for weak-scale dark matter searches, although we believe the spirit of the recommendations can apply more broadly to searches for other dark matter candidates, such as very light dark matter or axions. To translate experimental data into a final published result, direct detection collaborations must make a series of choices in their analysis, ranging from how to model astrophysical parameters to how to make statistical inferences based on observed data. While many collaborations follow a standard set of recommendations in some areas, for example the expected flux of dark matter particles (to a large degree based on a paper from Lewin and Smith in 1995), in other areas, particularly in statistical inference, they have taken different approaches, often from result to result by the same collaboration. We set out a number of recommendations on how to apply the now commonly used Profile Likelihood Ratio method to direct detection data. In addition, updated recommendations for the Standard Halo Model astrophysical parameters and relevant neutrino fluxes are provided. The authors of this note include members of the DAMIC, DarkSide, DARWIN, DEAP, LZ, NEWS-G, PandaX, PICO, SBC, SENSEI, SuperCDMS, and XENON collaborations, and these collaborations provided input to the recommendations laid out here. Wide-spread adoption of these recommendations will make it easier to compare and combine future dark matter results.
Maxwell field in spatially flat FLRW space-times
Authors: Cotăescu Ion I.
Published: October 2021

The classical and quantum theory of the Maxwell free field (or perturbation) minimally coupled to the gravity of local-Minkowskian spatially flat Friedmann–Lemaître–Robertson–Walker (FLRW) space-times is constructed in conformal local charts (herein called frames) where the Maxwell equations have the same form as in special relativity. Taking into account that the conformal coordinates cannot be measured directly, all the obtained results are transformed in physical frames, with cosmic time and space coordinates of Painlevé type, where these may take on a physical meaning. In these frames, the Maxwell theory is equivalent to the electrodynamics in flat macroscopic media whose constitutive equations predict magnetoelectric type effects interpreted here as a geometric induction. The given example is of a system of static charges giving rise simultaneously to time-dependent electric and magnetic fields that can be measured in physical frames. The quantization of the Maxwell free field in these manifolds is performed in a canonical manner using the momentum-helicity basis. The propagators in conformal and physical frames and the principal one-particle operators are written down. It is shown that this approach reveals a new behaviour of the one-particle wave packets during propagation and specific effects produced by the apparent horizons of the observers staying at rest in their proper physical frames.
VPNET: Variable Projection Networks
Authors: Kovács Péter , Bognár Gergő , Huber Christian , Huemer Mario
Published: October 2021

In this paper, we introduce VPNet, a novel model-driven neural network architecture based on variable projection (VP). Applying VP operators to neural networks results in learnable features, interpretable parameters, and compact network structures. This paper discusses the motivation and mathematical background of VPNet and presents experiments. The VPNet approach was evaluated in the context of signal processing, where we classified a synthetic dataset and real electrocardiogram (ECG) signals. Compared to fully connected and one-dimensional convolutional networks, VPNet offers fast learning ability and good accuracy at a low computational cost of both training and inference. Based on these advantages and the promising results obtained, we anticipate a profound impact on the broader field of signal processing, in particular on classification, regression and clustering problems.
Brain Networks Modulation in Young and Old Subjects During Transcranial Direct Current Stimulation Applied on Prefrontal and Parietal Cortex
Authors: Miraglia Francesca , Vecchio Fabrizio , Pellicciari Maria Concetta , Cespon Jesus , Rossini Paolo Maria
Published: October 2021

Evidence indicates that the transcranial direct current stimulation (tDCS) has the potential to transiently modulate cognitive function, including age-related changes in brain performance. Only a small number of studies have explored the interaction between the stimulation sites on the scalp, task performance, and brain network connectivity within the frame of physiological aging. We aimed to evaluate the spread of brain activation in both young and older adults in response to anodal tDCS applied to two different scalp stimulation sites: Prefrontal cortex (PFC) and posterior parietal cortex (PPC). EEG data were recorded during tDCS stimulation and evaluated using the Small World (SW) index as a graph theory metric. Before and after tDCS, participants performed a behavioral task; a performance accuracy index was computed and correlated with the SW index. Results showed that the SW index increased during tDCS of the PPC compared to the PFC at higher EEG frequencies only in young participants. tDCS at the PPC site did not exert significant effects on the performance, while tDCS at the PFC site appeared to influence task reaction times in the same direction in both young and older participants. In conclusion, studies using tDCS to modulate functional connectivity and influence behavior can help identify suitable protocols for the aging brain.
Stability analysis of circular orbits around a charged BTZ black hole spacetime in a nonlinear electrodynamics model via Lyapunov exponents
Authors: Giri Shobhit , Nandan Hemwati , Joshi Lokesh Kumar , Maharaj Sunil D.
Published: October 2021

We investigate the existence and stability of both the timelike and null circular orbits for a (2 + 1)-dimensional charged BTZ black hole in Einstein-nonlinear Maxwell gravity with a negative cosmological constant. The stability analysis of orbits is performed to study the possibility of chaos in geodesic motion for a special case of black hole so-called conformally invariant Maxwell spacetime. The computations of both proper time Lyapunov exponent [Formula: see text] and coordinate time Lyapunov exponent [Formula: see text] are useful to determine the stability of these circular orbits. We observe the behavior of the ratio [Formula: see text] as a function of radius of circular orbits for the timelike case in view of different values of charge parameter. However, for the null case, we calculate only the coordinate time Lyapunov exponent [Formula: see text] as there is no proper time for massless test particles. More specifically, we further analyze the behavior of the ratio of [Formula: see text] to angular frequency [Formula: see text], so-called instability exponent as a function of charge [Formula: see text] and parameter related to cosmological constant [Formula: see text] for the particular values of other parameters.
Improving the Classification Rate of Insulation Defects in Power Cables by Automatic Features Extraction and Sample Augmentation of Partial Discharge Signal
Authors: Sun Kang , Xuan Xuyang , Zhao Laijun , Long Jie
Published: October 2021

Conventional pattern recognition methods employed for differentiating the types of insulation defects in power cables usually rely on the manual extraction of partial discharge features, which is inefficient and easily affected by subjective uncertainty. This work addresses this problem by proposing a new framework based on the automatic features extraction of partial discharge signal. The method first applies a sliding time window to convert partial discharge signals in the time domain into two-dimensional images that serve directly as the input to the convolutional neural networks (CNNs). Then a nonlinear encoder is employed to automatically extract the features of the partial discharge image data as the input of CNNs for classification. In addition, we address the overfitting problem associated with the few-shot by applying a deep convolutional generative adversarial network (DCGAN) to augment the original training dataset. Experimental results demonstrate the validity of the proposed algorithm; it increases the classification accuracy by 4.18% relative to that achieved with manually extracted features; the overall accuracy of the proposed algorithm training with the augmented dataset is 3.175% higher than that with the original experimental dataset.
Performance Evaluation Model for Matrix Calculation on GPU
Authors: Yin Mengjia , Xu Xianbin , Zhang Tao , Ye Conghuan
Published: October 2021

Establishment of a performance evaluation model is a hotspot of current research. In this paper, the performance bottleneck is analyzed quantitatively, which provided programmers with a guidance to optimize the performance bottleneck. This paper takes a matrix as an example; the matrix is divided into a dense matrix or a sparse matrix. For dense matrix, the performance is first analyzed in a quantitative way, and an evaluation model is developed, which includes the instruction pipeline, shared memory, and global memory. For sparse matrix, this paper aims at the four formats of CSR, ELL, COO, and HYB, through the observation data obtained from the actual operation of large datasets, finds the relationship between the running time, dataset form, and storage model, and establishes their relational model functions. Through practical test and comparison, the error between the execution time of the test dataset that is predicted by the model function and the actual running time is found to be within a stable finite deviation threshold, proving that the model has certain practicability.
Voltage-Mode Biquad Filter Using Four OTAs and Its Application in Quadrature Oscillator with Noninteractive Control of the Oscillation Condition and Frequency
Authors: Wang San-Fu , Chen Hua-Pin , Ku Yitsen , Lee Chia-Ling
Published: October 2021

This paper presents an independently tunable, four-input, three-output, voltage-mode (VM) biquad filter consisting of four operational transconductance amplifiers (OTAs) and two grounded capacitors. The proposed circuit can simultaneously realize three basic biquad filtering functions for single input and three outputs. All five standard biquad filtering functions can be implemented with four inputs and single output by appropriate application of input voltage signals. The developed biquad filter with high input impedances enables noninteractive control of natural angular frequency and quality factor. By slightly modifying the proposed biquad filter, the VM quadrature sinusoidal oscillator with noninteractive control for the oscillation condition and the oscillation frequency has been achieved. Simulation and experimental results are used to validate theoretical predictions.
H(curl2)-conforming quadrilateral spectral element method for quad-curl problems
Authors: Wang Lixiu , Shan Weikun , Li Huiyuan , Zhang Zhimin
Published: October 2021

In this paper, we propose an [Formula: see text]-conforming quadrilateral spectral element method to solve quad-curl problems. Starting with generalized Jacobi polynomials, we first introduce quasi-orthogonal polynomial systems for vector fields over rectangles. [Formula: see text]-conforming elements over arbitrary convex quadrilaterals are then constructed explicitly in a hierarchical pattern using the contravariant transform together with the bilinear mapping from the reference square onto each quadrilateral. It is worth noting that both the simplest rectangular and quadrilateral spectral elements possess only 8 degrees of freedom on each physical element. In the sequel, we propose our [Formula: see text]-conforming quadrilateral spectral element approximation based on the mixed weak formulation to solve the quad-curl equation and its eigenvalue problem. Numerical results show the effectiveness and efficiency of our method.
Global solvability and asymptotic stabilization in a three-dimensional Keller–Segel–Navier–Stokes system with indirect signal production
Authors: Dai Feng , Liu Bin
Published: October 2021

This paper deals with the Keller–Segel–Navier–Stokes model with indirect signal production in a three-dimensional (3D) bounded domain with smooth boundary. When the logistic-type degradation here is weaker than the usual quadratic case, it is proved that for any sufficiently regular initial data, the associated no-flux/no-flux/no-flux/Dirichlet problem possesses at least one globally defined solution in an appropriate generalized sense, and that this solution is uniformly bounded in [Formula: see text] with any [Formula: see text]. Moreover, under an explicit condition on the chemotactic sensitivity, these solutions are shown to stabilize toward the corresponding spatially homogeneous state in the sense of some suitable norms. We underline that the same results were established for the corresponding system with direct signal production in a well-known result if the degradation is quadratic. Our result rigorously confirms that the indirect signal production mechanism genuinely contributes to the global solvability of the 3D Keller–Segel–Navier–Stokes system.
Covariance group for null geodesic expansion calculations, and its application to the apparent horizon
Authors: Adler Stephen L.
Published: October 2021

We show that the recipe for computing the expansions [Formula: see text] and [Formula: see text] of outgoing and ingoing null geodesics normal to a surface admits a covariance group with nonconstant scalar [Formula: see text], corresponding to the mapping [Formula: see text], [Formula: see text]. Under this mapping, the product [Formula: see text] is invariant, and thus the marginal surface computed from the vanishing of [Formula: see text], which is used to define the apparent horizon, is invariant. This covariance group naturally appears in comparing the expansions computed with different choices of coordinate system.
The role of noise in the early universe
Authors: Lozano Ezequiel , Mazzitelli Francisco Diego
Published: October 2021

In this paper, we consider a quantum mechanical system to model the effect of quantum fields on the evolution of the early universe. The system consists of an inverted oscillator bilinearly coupled to a set of harmonic oscillators. We point out that the role of noise may be crucial in the dynamics of the oscillator, which is analyzed using the theory of harmonic oscillators with random frequency. Using this analogy, we argue that due to the fluctuations around its mean value, a positive vacuum energy density would not produce an exponentially expanding but an oscillating universe, in the same fashion that an inverted pendulum is stabilized by random oscillations of the suspension point (stochastic Kapitza pendulum). The results emphasize the relevance of noise in the evolution of the scale factor.
Receptance-Based Computation of Stability Crossing Curves for Single-Input-Multiple-Output Second-Order Linear Systems with Two Time-Delays
Authors: Lv Zhong-Hui , Zhang Jia-Fan , Ouyang Huajiang
Published: October 2021

For a complete stability analysis of multi-dimensional controlled systems modeled in the framework of second-order linear differential equations with two time-delays, the determination of stability crossing curves (or stability switching curves) within the domain of the delays is significantly important. This paper presents a simple receptance-based approach to solve this problem for a single-input-multiple-output controlled system using its second-order model. The proposed approach is based on a reduced characteristic function of the controlled system. This characteristic function is directly related to the receptance of the uncontrolled system and has a peculiar form that is well-suited for an effective method of calculation of these curves. Moreover, this method can find the direction in which the characteristic roots cross the imaginary axis as the delays deviate from a stability crossing curve. An example case study with two independent and constant delays is given to demonstrate the effectiveness of the proposed approach.
Influence of Atmospheric Humidity on the Critical Buckling Load of Reinforced Concrete Columns
Authors: Magalhães Kaique Moreira Matos , Rebello da Fonseca Brasil Reyolando Manoel Lopes , de Macêdo Wahrhaftig Alexandre , Siqueira Gustavo Henrique , Bondarenko Iryna , Neduzha Larysa
Published: October 2021

In this paper, an evaluation of the influence of atmospheric humidity on the critical buckling load of reinforced concrete columns is performed. A particular case consisting of a real, extremely slender reinforced concrete pole was taken for the study. The chosen mathematical procedure for calculating the critical load is based on the Mechanics of Deformable Solids due to variations of structure vibration frequency over time. The rheological behavior of concrete related to creep and shrinkage, which illustrates the time-dependent aspect of the problem, was also considered in the analysis following normative recommendations from the Brazilian Association of Technical Standards (ABNT). In order to evaluate value changes of critical buckling loads, different time instants after loading the structure as well as different relative humidity from 0% to 100%, in 10% increments were considered. According to the selected criteria, it was possible to verify that a higher atmospheric humidity decreases the water transport from the interior out to the exterior surfaces of concrete, hence positively influencing structure stiffness. Therefore, the lowest reduction on critical buckling was 41.9% at 100% relative atmospheric humidity, versus the highest 60.7% at 0% relative humidity. A period of 7500 days after loading the structure was considered in the analysis.
A Unified Modeling Method for Dynamic Analyses of FGP Annular and Circular Plates with General Boundary Conditions
Authors: Lu J. , Hua X. , Chiu C. , Zhang X. , Li S. , Meng Z. , Xu W.
Published: October 2021

The porous material is an emerging lightweight material, which is able to reduce structural weight and also keeps the superiority of the structure. Therefore, this work is devoted to the investigation of the functionally graded porous (FGP) annular and circular plates with general boundary conditions. The unified modeling method is proposed by combining the first-order shear deformation theory, the virtual spring technology, the multi-segment partition method, and the semi-analysis Rayleigh–Ritz approach. Afterwards, the convergency and correctness of the proposed method are verified, respectively. The frequency parameters, modal shapes, and forced vibration responses are uniformly calculated based on the proposed method. Finally, the dynamic analyses of the FGP annular and circular plates with different parameters, such as the porosity distribution types, porosity ratios, boundary condition types, geometry parameters, and load types, are conducted in detail. It is found that the reasonable porous design is able to keep the dynamic stability of the structure under different parameter variations.
ORGANISING FOR INNOVATION IN PROFESSIONAL SERVICES FIRMS: ECONOMETRIC EVIDENCE FROM THE UK
Authors: BOURKE JANE , ROPER STEPHEN , LOVE JAMES H
Published: October 2021

Undertaking innovation involves a range of different activities from ideation to the commercialisation of innovations. Each activity may have very different resources and organisational requirements, however, most prior studies treat innovation as a single un-differentiated activity. Here, using new survey data for professional service firms (PSFs) in the UK, we are able to examine separately how a range of organisational work practices influence success in ideation and commercialisation. In particular, we use principal component analysis (PCA) to identify and compare the benefits of four groups of organisational work practices relating to strategy & information sharing, recruitment & training, work flexibility & discretion and culture & leadership. Strong contrasts emerge between those work practices that are important for success in ideation and commercialisation. Work practices linked to culture & leadership are important for ideation activities, while strategy &information sharing practices are more strongly associated with commercialisation success. The results suggest clear managerial implications depending on the priority