bluuebunny/crossref_metadata_2025 huggingface dataset:
Do black‐tailed prairie dog (Cynomys ludovicianus) colonies attract foraging bats?
Authors: Adams R. A.
Published: June 2021

Black‐tailed prairie dog (BTPD) colonies are known to be hotbeds of biodiversity. Manipulation of landscape by BTPDs increases plant and animal diversity in grasslands, and thus BTPDs are considered ecosystem engineers. If BTPD colonies induce increases in insect diversity in the eastern foothills of Colorado, as shown for other areas, it stands to reason that insectivorous bats may respond by increasing their activity in those areas. I tested this hypothesis in the north‐eastern foothills habitat of Colorado, USA, by surveying for echolocation calls within four BTPD colonies and adjacent reference sites lacking BTPD burrows. Results show that bats were significantly more active in BTPD colonies than at adjacent reference sites. In addition, of the nine resident bat species, small‐footed myotis (Myotis ciliolabrum) showed the most consistent relationship with BTPD colonies. Other species that were more active in BTPD colonies included little brown myotis (M. lucifugus), fringed myotis (M. thysanodes), big brown bats (Eptesicus fuscus), and hoary bats (Lasiurus cinereus). The typically forest‐edge adapted species, M. ciliolabrum, and M. thysanodes a forest‐adapted specialist, were active more than expected in treeless BTPD colonies indicating the BTPD colonies are providing a resource not present outside colony perimeters. This study provides the first evidence of a relationship between BTPD colonies and bats in western North America.
Psychiatric symptoms influence reward‐seeking and loss‐avoidance decision‐making through common and distinct computational processes
Authors: Suzuki Shinsuke , Yamashita Yuichi , Katahira Kentaro
Published: June 2021

Aim

Psychiatric symptoms are often accompanied by impairments in decision‐making to attain rewards and avoid losses. However, due to the complex nature of mental disorders (e.g., high comorbidity), symptoms that are specifically associated with deficits in decision‐making remain unidentified. Furthermore, the influence of psychiatric symptoms on computations underpinning reward‐seeking and loss‐avoidance decision‐making remains elusive. Here, we aim to address these issues by leveraging a large‐scale online experiment and computational modeling.

Methods

In the online experiment, we recruited 1900 non‐diagnostic participants from the general population. They performed either a reward‐seeking or loss‐avoidance decision‐making task, and subsequently completed questionnaires about psychiatric symptoms.

Results

We found that one trans‐diagnostic dimension of psychiatric symptoms related to compulsive behavior and intrusive thought (CIT) was negatively correlated with overall decision‐making performance in both the reward‐seeking and loss‐avoidance tasks. A deeper analysis further revealed that, in both tasks, the CIT psychiatric dimension was associated with lower preference for the options that recently led to better outcomes (i.e. reward or no‐loss). On the other hand, in the reward‐seeking task only, the CIT dimension was associated with lower preference for recently unchosen options.

Conclusion

These findings suggest that psychiatric symptoms influence the two types of decision‐making, reward‐seeking and loss‐avoidance, through both common and distinct computational processes.
Chill Pills Panic: Legal Constructions of Play, Race, and the Policing of Care in California's Administrative Courts
Authors: Valles Dario
Published: June 2021

US legal‐administrative interpretations of children's play offer critical insight into the production of racial difference and reproduction of economic disparities under the aegis of the postwelfare state. This article analyzes ethnographic observations in an administrative court in Los Angeles and transcripts of childcare license revocation hearings for an African American home‐based early education provider serving working‐class families via welfare‐to‐work systems. As courtroom ethnography reveals, US postwelfare institutions view play through an ideological prism that enshrines White middle‐class patterns of consumption as normative. Tasked with an ill‐defined postwelfare state mandate of early intervention, street‐level bureaucrats not only assess young Black and Latinx children as continual future threats but also as vulnerable in the present to their guardians’ poor choices.[childhood, race, care, administrative courts, play, postwelfare state]
Differential interactions of age and sleep deprivation in driving and spatial perception by male drivers in a virtual reality environment
Authors: Rashid Izullah Faramosh , af Schulten Anna , Koivisto Mika , Nieminen Valtteri , Luimula Mika , HÄmÄlÄinen Heikki
Published: June 2021

We determined the effects of age and sleep deprivation on driving and spatial perception in a virtual reality environment. Twenty‐two young (mean age: 22 years, range: 18–35) and 23 old (mean age: 71 years, range: 65–79) participants were tested after a normal night of sleep and a night of sleep deprivation. The participants drove a virtual car while responding to uni‐ and bilateral visual and auditory stimuli. Driving errors (crossing the lane borders), reaction times and accuracy to visual and auditory stimuli, performance in psychological tests, and subjective driving ability and tiredness were measured. Age had no effect on the number of driving errors, whereas sleep deprivation increased significantly especially the number of left lane border crossings. Age increased the number of stimulus detection errors, while sleep deprivation increased the number of errors particularly in the young and in the auditory modality as response omissions. Age and sleep deprivation together increased the number of response omissions in both modalities. Left side stimulus omissions suggest a bias to the right hemispace. The subjective evaluations were consistent with the objective measures. The psychological tests were more sensitive to the effects of age than to those of sleep deprivation. Driving simulation in a virtual reality setting is sensitive in detecting the effects of deteriorating factors on both driving and simultaneous spatial perception.
A spatially aware method for mapping movement‐based and place‐based regions from spatial flow networks
Authors: Sekulić Sebastijan , Long Jed , Demšar Urška
Published: June 2021

Community detection (CD) is a frequent method for analysing flow networks in geography. It allows us to partition the network into a set of densely interconnected regions, called communities. We introduce a new technique for including geographical weighting in existing methods for detecting spatially coherent communities. We take a link‐based CD algorithm and adjust it to incorporate geographical weighting. We call this approach geographically weighted community detection (GWCD). Our method is demonstrated on two case studies of commonly encountered flow networks: commuter flows and taxi pick‐up/drop‐off flows. Further, we test different measures of distance for geographic weighting and compare our results with the unmodified CD algorithm. Our results show that GWCD can capture the geographical nature of flow regions, generating spatially smaller and more compact areas than if geography is omitted, and that it can be used to distinguish between different types of movement‐type communities.
The vertebral heart scale on CT is correlated to radiographs in dogs
Authors: Timperman Lauren , Habing Greg , Green Eric
Published: June 2021

The vertebral heart scale (VHS) has long been used as an objective standard for evaluation of cardiac silhouette size on thoracic radiographs and plays a key role in the diagnosis as well as the assessment of the severity of canine heart disease. Based on our review of the literature, there has been no published study describing an objective method for measuring overall heart size using computed tomography (CT) in canine patients. The goals of this exploratory prospective method comparison study were to describe a method for objectively evaluating heart size on canine thoracic CT images, determine whether there was a correlation between the VHS when applied to a right lateral thoracic radiograph and a sagittal image of a thoracic CT scan, and determine the effect of cardiac phase on a VHS measured on CT. A method for measuring VHS on canine CT studies was defined. Data were collected on canine patients admitted to The Ohio State Veterinary Medical Center. Each patient received an ECG‐gated thoracic CT immediately followed by a right lateral thoracic radiograph. The VHS was measured on non‐gated, systolic, and diastolic sagittal CT reformatted images. Our results indicated that cardiac gating may not be necessary when assessing canine heart size on CT. When comparing the VHS on gated and non‐gated CT to the VHS on radiographs, there was a moderate to high degree of correlation; however, there was a high degree of variability between CT and radiography.
18Fluorine‐fluorodeoxyglucose positron emission tomography for assessment of deep digital flexor tendinopathy: An exploratory study in eight horses with comparison to CT and MRI
Authors: Wilson Sabrina , Spriet Mathieu , Mur Pablo Espinosa , Anishchenko Sergey , Beylin David , Katzman Scott , Galuppo Larry
Published: June 2021

Lesions of the deep digital flexor tendon (DDFT) are a cause for foot lameness in horses. Positron emission tomography (PET) could provide valuable information regarding the metabolic activity of these lesions. The aims of this exploratory, prospective, methods comparison study were to assess the ability of 18fluorine‐fluorodeoxyglucose (18F‐FDG) PET to detect DDFT lesions and to compare the PET findings with CT and MRI findings. Eight horses with lameness due to pain localized to the front feet were included. Both front limbs of all horses were imaged with 18F‐FDG PET, noncontrast CT, and arterial contrast‐enhanced CT; 11 limbs were also assessed using MRI. Two observers graded independently 18F‐FDG PET, noncontrast CT, arterial contrast CT, T1‐weighted (T1‐w) MRI, and T2‐weighted (T2‐w)/STIR MRI. Maximal standardized uptake values were measured. Lesions were found in seven of 16 DDFT on PET, 12 of 16 DDFT on noncontrast CT, six of 15 DDFT on arterial contrast CT, eight of 11 DDFT on T1‐w MRI, and six of 11 DDFT on T2‐w/STIR MRI. Positron emission tomography was in better agreement with arterial contrast CT (Kappa‐weighted 0.40) and T2‐w/STIR MRI (0.35) than with noncontrast CT (0.28) and T1‐w MRI (0.20). Maximal standardized uptake values of lesions ranged from 1.9 to 4.6 with a median of 3.1. Chronic lesions with scar tissues identified on noncontrast CT or T1‐w MRI did not have increased 18F‐FDG uptake. These results demonstrated that 18F‐FDG PET agreed more closely with modalities previously used to detect active tendon lesions, i.e. arterial contrast CT and T2‐w/STIR MRI. 18Fluorine‐fluorodeoxyglucose PET can be used to identify metabolically active DDFT lesions in horses.
Empathy and Low Participation of Women in Engineering: Is There a Hidden Link
Authors: Xu Yonghong Jade , Jacobs Eddie , Astorne-Figari Carmen , De Jongh Curry Amy L. , Roberts Shelby G. , Deaton Russel J.
Published: June 2021

Women are severely underrepresented in science, technology, engineering, and mathematics (STEM) education and the related work force. One of the reasons for the low presence of women in engineering is a lack of connection between engineering-related values and women’s personal values and beliefs, in particular the difference in empathy value. This study examined how empathy may have contributed to the low enrollment of women in engineering majors. An online survey was used to collect data from undergraduate students in an urban university in the United States. Statistical procedures were carefully selected to analyze the survey data and answer the four research questions. The results indicate that 1) students with a stronger empathizing trait reported lower likelihood of majoring in engineering; and 2) the perceived empathy level of a given academic discipline was a significant factor in students’ major choice. The lower likelihood of majoring in engineering was associated with its low empathy level perceived by the students. The major findings of the study call for reformulation of the engineering education so that human-centered values can be emphasized as critical components to the existing curricula.
Circus activities as a health intervention for children, youths, and adolescents: a scoping review protocol
Authors: Coulston Free , Cameron Kate L. , Spittle Alicia , Sellick Kath , Toovey Rachel
Published: June 2021

Objective:

This scoping review aims to map the evidence on circus activities described and/or evaluated as a health intervention for children, youths, and adolescents. Increased understanding of how these interventions work, and gaps identified, will allow researchers and practitioners to advance the science behind these approaches.

Introduction:

Circus activities are proposed in the literature as a health intervention, due to their variety, non-competitive nature, and potential to develop fundamental physical and social skills. For the purposes of this review, circus activities as a health intervention are defined as aerial, acrobatic, equilibristic, and manipulation skills taught to participants to maintain, improve, or modify health, functioning, or health conditions.

Inclusion criteria:

English-language evidence will be considered where circus activities as a health intervention are described and/or evaluated for participants up to 24 years of age, or who are defined as children, youths, or adolescents. Literature will be excluded where the focus of the intervention is clowning, magic, or drama games, or where circus activities are not the therapeutic part of the activity.

Methods:

MEDLINE (Ovid), CINAHL Complete (EBSCO), Scopus (Elsevier), PsycINFO (Ovid), ProQuest Dissertations and Theses Global, and Google Scholar will be searched for peer-reviewed and gray literature. No restriction on dates, type, methodology, or setting will be imposed, but limits will include “human” and “English language.” Screening and data extraction will be performed by two independent reviewers. Reference lists of included sources will be screened. Results will be presented in diagrammatic or tabular format, alongside a narrative description, under headings aligning with the research sub-questions.
Moderate‐intensity aerobic training reduces cardiac damage attributable to experimental iron overload in rats
Authors: Ávila Renata Andrade , Rossi Emilly Martinelli , de Carvalho Guilherme Mendes , Krause Maiara , Leopoldo André Soares , Carneiro Maria Tereza W. D. , dos Santos Leonardo
Published: June 2021

New Findings

What is the central question of this study?

The current literature indicates that oxidative stress plays a major role in iron overload. Although exercise is a well‐established approach to treat/prevent cardiovascular diseases, its effects on iron overload are not known.

What is the main finding and its importance?

Moderate‐intensity aerobic training had benefits in a rodent model of iron‐overload cardiomyopathy by improving the antioxidant capacity of the heart. After further confirmation by translational and clinical studies, we should consider using this non‐pharmacological, highly accessible and easily executable adjuvant approach allied to other therapies to improve the quality of life of iron‐overloaded patients.

Iron is an essential micronutrient for several life processes, but its excess can damage organs owing to oxidative stress, with cardiomyopathy being the leading cause of death in iron‐overloaded patients. Although exercise has long been considered as a cardioprotective tool, its effects on iron overload are not known. This study was designed to investigate the effects of moderate‐intensity aerobic training in rats previously submitted to chronic iron overload. Wistar rats received i.p. injections of iron dextran (100 mg/kg, 5 days/week for 4 weeks); thereafter, the rats were kept sedentary or exercised (60 min/day, progressive aerobic training, 60–70% of maximal speed, 5 days/week on a treadmill) for 8 weeks. At the end of the experimental period, haemodynamics were recorded and blood samples, livers and hearts harvested. Myocardial mechanics of papillary muscles were assessed in vitro, and cardiac remodelling was evaluated by histology and immunoblotting. Iron overload led to liver iron deposition, liver fibrosis and increased serum alanine aminotransferase and aspartate aminotransferase. Moreover, cardiac iron accumulation was accompanied by impaired myocardial mechanics, increased cardiac collagen type I and lipid peroxidation (TBARS), and release of creatine phosphokinase‐MB to the serum. Although exercise did not influence iron levels, tissue injury markers were significantly reduced. Likewise, myocardial contractility and inotropic responsiveness were improved in exercised rats, in association with an increase in the endogenous antioxidant enzyme catalase. In conclusion, moderate‐intensity aerobic exercise was associated with attenuated oxidative stress and cardiac damage in a rodent model of iron overload, thereby suggesting its potential role as a non‐pharmacological adjuvant therapy for iron‐overload cardiomyopathy.
Muscarinic regulation of the neuronal Na+/K+‐ATPase in rat hippocampus
Authors: Mohan Sandesh , Tiwari Manindra Nath , Stanojević Marija , Biala Yoav , Yaari Yoel
Published: June 2021

Key points

Stimulation of postsynaptic muscarinic receptors was shown to excite principal hippocampal neurons by modulating several membrane ion conductances.

We show here that activation of postsynaptic muscarinic receptors also causes neuronal excitation by inhibiting Na+/K+‐ATPase activity.

Muscarinic Na+/K+‐ATPase inhibition is mediated by two separate signalling pathways that lead downstream to enhanced Na+/K+‐ATPase phosphorylation by activating protein kinase C and protein kinase G.

Muscarinic excitation through Na+/K+‐ATPase inhibition is probably involved in cholinergic modulation of hippocampal activity and may turn out to be a widespread mechanism of neuronal excitation in the brain.

Stimulation of muscarinic cholinergic receptors on principal hippocampal neurons enhances intrinsic neuronal excitability by modulating several membrane ion conductances. The electrogenic Na+/K+‐ATPase (NKA; the ‘Na+ pump’) is a ubiquitous regulator of intrinsic neuronal excitability, generating a hyperpolarizing current to thwart excessive neuronal firing. Using electrophysiological and pharmacological methodologies in rat hippocampal slices, we show that neuronal NKA pumping activity is also subjected to cholinergic regulation. Stimulation of postsynaptic muscarinic, but not nicotinic, cholinergic receptors activates membrane‐bound phospholipase C and hydrolysis of membrane‐integral phosphatidylinositol 4,5‐bisphosphate into diacylglycerol (DAG) and inositol 1,4,5‐triphosphate (IP3). Along one signalling pathway, DAG activates protein kinase C (PKC). Along a second signalling pathway, IP3 causes Ca2+ release from the endoplasmic reticulum, facilitating nitric oxide (NO) production. The rise in NO levels stimulates cGMP synthesis by guanylate‐cyclase, activating protein kinase G (PKG). The two pathways converge to cause partial NKA inhibition through enzyme phosphorylation by PKC and PKG, leading to a marked increase in intrinsic neuronal excitability. This novel mechanism of neuronal NKA regulation probably contributes to the cholinergic modulation of hippocampal activity in spatial navigation, learning and memory.
Development of 3D Cerebral Aggregates in the Brain Ventricles of Adult Mice
Authors: Sukhinich K. K. , Shakirova K. M. , Dashinimaev E. B. , Aleksandrova M. A.
Published: June 2021

The cerebral organoids are three-dimensional cell cultures formed from brain-specific cell types arising from embryonic or pluripotent stem cells. Organoids provide an opportunity to study the early stages of brain development and diseases of the central nervous system. However, the modeling of organoids is associated with a number of unsolved problems. Organoid production techniques involve a complex cell culture process that requires special media, growth factors, and often the use of a bioreactor. Even under standardized conditions, structures of different morphology are formed: from disorganized cell aggregates to structured minibrains, which are selected for study. For natural reasons, organoids grown in vitro do not have a blood supply, which limits their development. We tried to obtain cerebral aggregates similar to organoids in an in vivo model, where vascular growth and tissue blood supply are provided, for which we transplanted a cell suspension from the mouse embryonic neocortex into the lateral ventricles of the brain of adult mice. Therefore, the medium for cultivation was the cerebrospinal fluid, and the lateral ventricles of the brain, where it circulates, served as a bioreactor. The results showed that the neocortex from E14.5 is a suitable source of stem/progenitor cells that self-assemble into three-dimensional aggregates and vascularized in vivo. The aggregates consisted of a central layer of mature neurons, the marginal zone free of cells and a glia limitans, which resembled cerebral organoids. Thus, the lateral ventricles of the adult mouse brain can be used to obtain vascularized cell aggregates resembling cerebral organoids.
Off-tumor IDO1 target engagements determine the cancer-immune set point and predict the immunotherapeutic efficacy
Authors: Xie Lin , Hu Kuan , Duo Yanhong , Shimokawa Takashi , Kumata Katsushi , Zhang Yiding , Jiang Cuiping , Zhang Lulu , Nengaki Nobuki , Wakizaka Hidekatsu , Cao Yihai , Zhang Ming-Rong
Published: June 2021

Background

Indoleamine-2,3-dioxygenase 1 (IDO1) has been intensively pursued as a therapeutic target to reverse the immunosuppressive cancer-immune milieu and promote tumor elimination. However, recent failures of phase III clinical trials with IDO1 inhibitors involved in cancer immunotherapies highlight the urgent need to develop appropriate methods for tracking IDO1 when the cancer-immune milieu is therapeutically modified.

Methods

We utilized a small-molecule radiotracer, 11C-l-1MTrp, to quantitatively and longitudinally visualize whole-body IDO1 dynamics. Specifically, we first assessed 11C-l-1MTrp in mice-bearing contralateral human tumors with distinct IDO1 expression patterns. Then, we applied 11C-l-1MTrp to longitudinally monitor whole-body IDO1 variations in immunocompetent melanoma-bearing mice treated with 1-methyl-l-tryptophan plus either chemotherapeutic drugs or antibodies targeting programmedcell death 1 and cytotoxic T-lymphocyte-associated protein 4.

Results

11C-l-1MTrp positron emission tomography (PET) imaging accurately delineated IDO1 expression in xenograft mouse models. Moreover, we were able to visualize dynamic IDO1 regulation in the mesenteric lymph nodes (MLNs), an off-tumor IDO1 target, where the percentage uptake of 11C-l-1MTrp accurately annotated the therapeutic efficacy of multiple combination immunotherapies in preclinical models. Remarkably, 11C-l-1MTrp signal intensity in the MLNs was inversely related to the specific growth rates of treated tumors, suggesting that IDO1 expression in the MLNs can serve as a new biomarker of the cancer-immune set point.

Conclusions

PET imaging of IDO1 with 11C-l-1MTrp is a robust method to assess the therapeutic efficacy of multiple combinatorial immunotherapies, improving our understanding of the merit and challenges of IDO1 regimens. Further validation of this animal data in humans is ongoing. We envision that our results will provide a potential precision medicine paradigm for noninvasive visualizing each patient’s individual response in combinatorial cancer immunotherapy, and tailoring optimal personalized combination strategies.
Regularization ambiguity and van der Waals black hole in 2 + 1 dimensions
Authors: Gaete Patricio , Nicolini Piero , Spallucci Euro
Published: June 2021

Charged black holes in a ($$2+1$$

2
+
1

)-dimensional anti-de Sitter space-time suffer from some limitations such as the ambiguity in the definition of the mass and the bad short distance behavior. In this paper we present a way to resolve such issues. By extending the parameter space of the BTZ geometry, we properly identify the integration constants in order to remove the conical singularity sitting at the origin. In such a way we obtain a well defined Minkowski limit and horizons also in the case of de Sitter background space. On the thermodynamic side, we obtain a proper internal energy, by invoking the consistency with the Area Law, even if the mass parameter does not appear in the metric coefficients. As a further improvement, we show that it is sufficient to assume a finite size of the electric charge to obtain a short scale regular geometry. The resulting solution, generalizing the charged BTZ metric, is dual to a van der Waals gas.
Anisotropic generalization of Buchdahl bound for specific stellar models
Authors: Sharma Ranjan , Ghosh Arpita , Bhattacharya Soumik , Das Shyam
Published: June 2021

Anisotropy is one factor that appears to be significantly important in the studies of relativistic compact stars. In this paper, we make a generalization of the Buchdahl limit by incorporating an anisotropic effect for a selected class of exact solutions describing anisotropic stellar objects. In the isotropic case of a homogeneous distribution, we regain the Buchdahl limit $$2M/R \le 8/9$$

2
M
/
R
≤
8
/
9

. Our investigation shows a direct link between the maximum allowed compactness and pressure anisotropy vi-a-vis geometry of the associated 3-space.
Investigation on the New Physics effects of the vector leptoquark on semileptonic $$\bar{B}^*\rightarrow V \tau ^-\bar{\nu _{\tau }}$$ decays
Authors: Sheng Jin-Huan , Zhu Jie , Hu Quan-Yi
Published: June 2021

In recent years, the experimental results about the ratio of the branching ratios $$R_{D^{(*)}}$$

R

D

(

∗
)

and $$R_{K^{(*)}}$$

R

K

(

∗
)

, which are in the semileptonic $$b\rightarrow c l \bar{\nu }_{l}$$

b
→
c
l

ν

¯

l

and $$b\rightarrow s l^+l^-$$

b
→
s

l
+

l
-

decays, have been observed to deviate from the Standard Model prediction by $$1.4\sigma $$

1.4
σ

, $$2.5\sigma $$

2.5
σ

, $$2.4\sigma $$

2.4
σ

and $$2.2\sigma $$

2.2
σ

respectively. Motivated by these anomalies and by the abundant $$B^*$$

B
∗

data samples, we investigate possible New Physics effects of the vector leptoquark in the semileptonic decay $$\bar{B}^*_{u,d,s,c} \rightarrow V \tau ^-\bar{\nu }_{\tau }$$

B

¯

u
,
d
,
s
,
c

∗

→
V

τ
-

ν

¯

τ

($$V=D^*_{u,d,s},J/\psi $$

V
=

D

u
,
d
,
s

∗

,
J
/
ψ

). which is induced by $$b\rightarrow c \tau ^-\bar{\nu }_{\tau }$$

b
→
c

τ
-

ν

¯

τ

at the quark level. Using the best fit solutions for the new operator Wilson coefficients and the relevant form factors which are obtained in the light-front quark model, we find that (i) the contributions of the vector leptoquark to $$d{\varGamma }^{(L)}/dq^2(\bar{B}^*_{u,d,s,c} \rightarrow V \tau ^-\bar{\nu }_{\tau })$$

d

Γ

(
L
)

/
d

q
2

(

B

¯

u
,
d
,
s
,
c

∗

→
V

τ
-

ν

¯

τ

)

and $$R^{*(L)}_{V}(q^2)$$

R
V

∗
(
L
)

(

q
2

)

to be significant; (ii) the two best fit solutions in the vector leptoquark are indistinguishable from each other and give similar amounts of enhancements to these two observables; (iii) both two cases of the vector leptoquark give nearly same results as those of the Standard Model for $$A_{FB}^{\tau }(q^2)$$

A

FB

τ

(

q
2

)

, $$P_{\tau }(q^2)$$

P
τ

(

q
2

)

and $$F_{L}^{*V}(q^2)$$

F

L

∗
V

(

q
2

)

. We hope that the numerical results in this work will be tested in the future high energy experiments.
Anisotropic power-law inflation for a model of two scalar and two vector fields
Authors: Do Tuan Q. , Kao W. F.
Published: June 2021

Inspired by an interesting counterexample to the cosmic no-hair conjecture found in a supergravity-motivated model recently, we propose a multi-field extension, in which two scalar fields are allowed to non-minimally couple to two vector fields, respectively. This model is shown to admit an exact Bianchi type I power-law solution. Furthermore, stability analysis based on the dynamical system method is performed to show that this anisotropic solution is indeed stable and attractive if both scalar fields are canonical. Nevertheless, if one of the two scalar fields is phantom then the corresponding anisotropic power-law inflation turns unstable as expected.
Born sigma-models for para-Hermitian manifolds and generalized T-duality
Authors: Marotta Vincenzo Emilio , Szabo Richard J.
Published: June 2021

We give a covariant realization of the doubled sigma-model formulation of duality-symmetric string theory within the general framework of para-Hermitian geometry. We define a notion of generalized metric on a para-Hermitian manifold and discuss its relation to Born geometry. We show that a Born geometry uniquely defines a worldsheet sigma-model with a para-Hermitian target space, and we describe its Lie algebroid gauging as a means of recovering the conventional sigma-model description of a physical string background as the leaf space of a foliated para-Hermitian manifold. Applying the Kotov–Strobl gauging leads to a generalized notion of T-duality when combined with transformations that act on Born geometries. We obtain a geometric interpretation of the self-duality constraint that halves the degrees of freedom in doubled sigma-models, and we give geometric characterizations of non-geometric string backgrounds in this setting. We illustrate our formalism with detailed worldsheet descriptions of closed string phase spaces, of doubled groups where our notion of generalized T-duality includes non-abelian T-duality, and of doubled nilmanifolds.
Moduli spaces of abstract and embedded Kummer varieties
Authors: Galeotti Mattia , Perna Sara
Published: June 2021

In this paper, we investigate the construction of two moduli stacks of Kummer varieties. The first one is the stack [Formula: see text] of abstract Kummer varieties and the second one is the stack [Formula: see text] of embedded Kummer varieties. We will prove that [Formula: see text] is a Deligne-Mumford stack and its coarse moduli space is isomorphic to [Formula: see text], the coarse moduli space of principally polarized abelian varieties of dimension [Formula: see text]. On the other hand, we give a modular family [Formula: see text] of embedded Kummer varieties embedded in [Formula: see text], meaning that every geometric fiber of this family is an embedded Kummer variety and every isomorphic class of such varieties appears at least once as the class of a fiber. As a consequence, we construct the coarse moduli space [Formula: see text] of embedded Kummer surfaces and prove that it is obtained from [Formula: see text] by contracting the locus swept by a particular linear equivalence class of curves. We conjecture that this is a general fact: [Formula: see text] could be obtained from [Formula: see text] via a contraction for all [Formula: see text].
Differential equations with multiple sign changing convolution coefficients
Authors: Goodrich Christopher S.
Published: June 2021

For continuous functions [Formula: see text] and [Formula: see text], which are allowed to change sign, we consider the nonlocal differential equation [Formula: see text] where [Formula: see text], [Formula: see text] and [Formula: see text] represents the finite convolution of the functions [Formula: see text] and [Formula: see text]. A model case is the equation [Formula: see text] The existence of at least one positive solution to these problems subjected to a variety of boundary conditions is studied. Due to the use of a nonstandard order cone we are able to achieve our results without having to assume that the coefficients [Formula: see text] and [Formula: see text] are strictly positive.
Modeling the coupling between a COVID-19-like epidemic and the economy
Authors: Aucouturier Matthieu , Herrmann Hans J.
Published: June 2021

We consider a compartmental model adapted to the case of COVID-19 that takes into account the detection of ill individuals and the cost of medical treatment and investigate the effect of a budget constraint. Our analysis shows how the collapse of the budget can drastically change the outcome of an epidemics. We see how with a good testing policy the epidemic might be controllable. By introducing a lockdown period, we show that the final number of deaths can be reduced substantially and observe that a budget collapse introduces rather extreme effects. We find that there exists a well-defined optimal starting point for a lockdown. We also looked at the consequences of a loss of immunity and found that then a budget collapse can occur for smaller costs of medical treatment.
Shape isomerism and magicity in Ni isotopes
Authors: Naz Tabassum , Ahmad Shakeb , Abusara H.
Published: June 2021

A systematic study of shapes in Ni [Formula: see text] isotopes has been made in the Relativistic–Hartree–Bogoliubov (RHB) formalism with two types of density-dependent NN interactions which are based on the range of meson-exchange. The constraint calculations assuming the axial and triaxial-symmetry predict the shape isomerism in the case of [Formula: see text] isotopes. Significant jumps at [Formula: see text] in the binding energy per nucleon (BE/A) and in the [Formula: see text] correspond to the neutron shell closure, and [Formula: see text] as doubly magic nuclei. The present calculation supports the recently reported calculations using the non-relativistic Hartree–Fock (HF) Skyrme SIII [1] interaction predicting the importance of tensor parameter in order to reproduce the experimental findings of the proton level crossing at [Formula: see text]. The results obtained are in agreement with experiment and with other theoretical studies.
On the reformulation of the Thomas–Fermi model to make it compatible with the Planck-scale
Authors: Barman Himangshu , Rahaman Anisur , Jha Sohan Kumar
Published: June 2021

Thomas–Fermi model is considered here to make it cogent to capture the Planck-scale effect with the use of a generalization of uncertainty relation. Here generalization contains both linear and quadratic terms of momentum. We first reformulate the Thomas–Fermi model for the non-relativistic case. We have shown that it can also be reformulated for taking into account the relativistic effect. We study the dialectic screening for both the non-relativistic and relativistic cases and find out the Fermi length for both the cases explicitly.
Dark matter from a dark connection
Authors: Das Ranit , Krishnan Chethan
Published: June 2021

In the first part of this note, we observe that a non-Riemannian piece in the affine connection (a “dark connection”) leads to an algebraically determined, conserved, symmetric 2-tensor in the Einstein field equations that is a natural dark matter candidate. The only other effect it has, is through its coupling to standard model fermions via covariant derivatives. If the local dark matter density is the result of a background classical dark connection, these Yukawa-like mass corrections are minuscule ([Formula: see text] for terrestrial fermions) and none of the tests of general relativity or the equivalence principle are affected. In the second part of the note, we give dynamics to the dark connection and show how it can be re-interpreted in terms of conventional dark matter particles. The simplest way to do this is to treat it as a composite field involving scalars or vectors. The (pseudo-)scalar model naturally has a perturbative shift-symmetry and leads to versions of the Fuzzy Dark Matter (FDM) scenario that has recently become popular (e.g. arXiv:1610.08297) as an alternative to WIMPs. A vector model with a [Formula: see text]-parity falls into the Planckian Interacting Dark Matter (PIDM) paradigm, introduced in arXiv:1511.03278. It is possible to construct versions of these theories that yield the correct relic density, fit with inflation and are falsifiable in the next round of CMB experiments. Our work is an explicit demonstration that the meaningful distinction is not between gravity modification and dark matter, but between theories with extra fields and those without.
Anomaly in the differential cross sections at 13 TeV
Authors: Selyugin O. V.
Published: June 2021

The analysis of the new TOTEM data at 13 TeV in a wide momentum transfer region reveals the unusual phenomenon — the presence in the elastic scattering amplitude of a term with a very large slope that is responsible for the behavior of hadron scattering at a very small momentum transfer. This term can be connected with hadron interactions at large distances.
Probability, preclusion and biological evolution in Heisenberg-picture Everett quantum mechanics
Authors: Rubin Mark A.
Published: June 2021

The fact that certain “extraordinary” probabilistic phenomena — in particular, macroscopic violations of the second law of thermodynamics — have never been observed to occur can be accounted for by taking hard preclusion as a basic physical law, i.e. precluding from existence events corresponding to very small but nonzero values of quantum-mechanical weight. This approach is not consistent with the usual ontology of the Everett interpretation, in which outcomes correspond to branches of the state vector, but can be successfully implemented using a Heisenberg-picture-based ontology in which outcomes are encoded in transformations of operators. Hard preclusion can provide an explanation for biological evolution, which can in turn explain our subjective experiences of, and reactions to, “ordinary” probabilistic phenomena, and the compatibility of those experiences and reactions with what we conventionally take to be objective probabilities arising from physical laws.
Model independent analysis of Dirac CP violating phase for some well-known mixing scenarios
Authors: Garg Sumit K.
Published: June 2021

In this paper, we present a model independent analysis of Leptonic CP violation for some well-known mixing scenarios. In particular, we considered modified schemes for bimaximal (BM), democratic (DC), hexagonal (HG) and tribimaximal (TBM) mixing for our numerical investigation. These model independent corrections to mixing matrices are parametrized in terms of complex rotation matrices [Formula: see text] with related modified PMNS matrix of the forms [Formula: see text] where [Formula: see text] is a complex rotation in [Formula: see text] sector and [Formula: see text] is unperturbed mixing scheme. We present generic formulae for mixing angles, Dirac CP phase [Formula: see text] and Jarlskog invariant [Formula: see text] in terms of correction parameters. The parameter space of each modified mixing case is scanned for fitting neutrino mixing angles using [Formula: see text] approach and the corresponding predictions for Leptonic CP phase [Formula: see text] and Jarlskog invariant [Formula: see text] has been evaluated from allowed parameter space. The obtained ranges are reported for all viable cases.
Design Space Exploration of Matrix–Matrix Convolution Operation
Authors: Behera Piyalee , Deb Arighna
Published: June 2021

Convolution is an important operation in neural networks which, in recent years, received significant attention from the researchers thanks to its ability to handle complex tasks such as image processing, computer vision in an efficient manner. In general, the convolution operation in neural networks considers two matrices as inputs: an image matrix representing an image and a kernel matrix required for necessary image processing operation and performs several multiplications and addition operations among the elements of image and kernel matrices. Realizing a circuit structure for matrix–matrix convolution is straightforward as each multiplication is realized by a multiplier, whereas an addition is carried out by an adder. However, the corresponding circuits result in large area, high power consumption and long delay because of the large number of multiplications and additions that are involved in the matrix–matrix convolution operations.

While, the existing approaches focus on the accelerations of this computationally intensive tasks, they often do not guarantee minimality of area, power and delay. But we show that there exists design aspects through which the circuit structures for convolution operations can be realized with less area, power and delay. To do this, we consider the kernel definitions during the design of the circuit structures since the kernel matrices are often (pre)-determined based on the desired applications. Motivated by this, we first explore the design space of the convolution operation by introducing an alternative design scheme for realizing the respective operation between two matrices keeping the image processing/neural network applications in mind. Experimental evaluations confirm the potential benefits of the proposed design scheme and demonstrate that the reductions in the area and power by approximately [Formula: see text] and critical path delay by approximately [Formula: see text] can be achieved using the proposed design scheme. In addition, the FPGA implementations of the proposed scheme also show that the reductions of approximately [Formula: see text] and [Formula: see text] in the number of LUTs and in the number of pins, respectively, can be achieved. Compared to prior works, the proposed scheme allows higher parallelism with minimum LUT utilization.
Parallel Implementation of Swarm Intelligent Algorithms in a Spark-Based Cloud Computing Environment
Authors: Zhu Jun , Wang Yushen
Published: June 2021

Swarm intelligent algorithms can effectively tackle optimization problems that are difficult to solve by using traditional optimization algorithms. However, with the huge increase in the time and space cost for solving optimization problems, the use of swarm intelligent algorithms suffer from the limitation of overly long computation time. Based on Spark, which is the most popular open-source distributed computing framework, this paper studies specifically using swarm intelligent algorithms to solve combinatorial optimization problems. Based on the characteristics of typical swarm intelligent algorithms, we develop Spark-based parallel implementation of these algorithms to accelerate the population updating and parameter tuning procedures involved in swarm intelligence. Specifically, we first initialize the swarm and generate the initial solution, then perform the distributed iterative evolution procedure, and finally obtain the optimal solution. In addition, in order to improve solution quality, we rely on the Spark platform to perform distributed parameter tuning. The tuning strategy first generates different parameter combinations according to a given parameter list, then execute swarm intelligent algorithms with different parameter combinations in a distributed and parallel manner, and finally determine the optimal parameter combination by comparing the solutions of all algorithms. Experimental results on benchmark datasets show that the distributed algorithms can significantly enhance the computational efficiency without affecting the solution quality.
Hausdorff dimension of the second Grigorchuk group
Authors: Noce Marialaura , Thillaisundaram Anitha
Published: June 2021

We show that the Hausdorff dimension of the closure of the second Grigorchuk group is [Formula: see text]. Furthermore, we establish that the second Grigorchuk group is super strongly fractal and that its automorphism group equals its normalizer in the full automorphism group of the tree.
Schreier graphs of spinal groups
Authors: Nagnibeda Tatiana , Pérez Aitor
Published: June 2021

We study Schreier dynamical systems associated with a vast family of groups that hosts many known examples of groups of intermediate growth. We are interested in the orbital graphs for the actions of these groups on [Formula: see text]-regular rooted trees and on their boundaries, viewed as topological spaces or as spaces with measure. They form interesting families of finitely ramified graphs, and we study their combinatorics, their isomorphism classes and their geometric properties, such as growth and the number of ends.
An amalgam of inverse semigroups is embedded into an amalgam with a lower bounded core
Authors: Bennett Paul
Published: June 2021

Given any amalgam [Formula: see text] of inverse semigroups, we show how to construct an amalgam [Formula: see text] such that [Formula: see text] is embedded into [Formula: see text], where [Formula: see text], [Formula: see text], [Formula: see text] and, for any [Formula: see text] and [Formula: see text] with [Formula: see text] in [Formula: see text], where [Formula: see text], there exists [Formula: see text] with [Formula: see text] in [Formula: see text]; that is, [Formula: see text] is a lower bounded subsemigroup of [Formula: see text] and [Formula: see text]. A recent paper by the author describes the Schützenberger automata of [Formula: see text], for an amalgam [Formula: see text] where [Formula: see text] is lower bounded in [Formula: see text] and [Formula: see text], giving conditions for [Formula: see text] to have decidable word problem. Thus we can study [Formula: see text] by considering [Formula: see text]. As an example, we generalize results by Cherubini, Jajcayová, Meakin, Piochi and Rodaro on amalgams of finite inverse semigroups.
Maximal independent sets and regularity of graphs
Authors: Trung Tran Nam
Published: June 2021

In this paper, we give a lower bound of the number of maximal independent sets in a graph [Formula: see text] in terms of the Castelnuovo–Mumford regularity of its edge ideal. We also find two classes of graphs achieving this minimum value.
Euclidean gravity and holography
Authors: Harlow Daniel , Shaghoulian Edgar
Published: June 2021

We discuss a recent proposal that the Euclidean gravity approach to quantum gravity is correct if and only if the theory is holographic, providing several examples and general arguments to support the conjecture. This provides a natural mechanism for the low-energy gravitational effective field theory to access a host of deep ultraviolet properties, like the Bekenstein–Hawking entropy of black holes, the unitarity of black hole evaporation, and the lack of exact global symmetries.
Thermodynamic properties of modified hairy and BTZ black holes
Authors: Yasir Muhammad , Bamba Kazuharu , Jawad Abdul
Published: June 2021

We consider the Hairy black hole of dimensionally continued gravity with power-Yang–Mills magnetic source and Lorentz symmetry violating Bañados, Teitelboim and Zanelli (BTZ) black hole in massive gravity. We utilize the general form of first law of black hole thermodynamics and compute different thermodynamic quantities. Keeping in mind the importance of negative cosmological constant [Formula: see text], we derive corresponding equations of state and discuss the phase transitions which is comparable with chemical Van der Waals fluid. We also find out the critical points and observe that system exhibits first-order small as well as large black holes phase transitions.
TEMPERED FRACTIONAL CALCULUS ON TIME SCALE FOR DISCRETE-TIME SYSTEMS
Authors: FU HUI , HUANG LAN-LAN , ABDELJAWAD THABET , LUO CHENG
Published: June 2021

The fractional derivative holds historical dependence or non-locality and it becomes a powerful tool in many real-world applications. But it also brings error accumulation of the numerical solutions as well as the theoretical analysis since many properties from the integer order case cannot hold. This paper defines the tempered fractional derivative on an isolated time scale and suggests a new method based on the time scale theory for numerical discretization. Some useful properties like composition law and equivalent fractional sum equations are derived for theoretical analysis. Finally, numerical formulas of fractional discrete systems are provided. As a special case for the step size [Formula: see text], a fractional logistic map with two-parameter memory effects is reported.