Search

The ultimate goal of this work is to create an engineered aerosol that acts as one‐way smoke, i.e. it creates an asymmetric vision environment in which the ability to image objects depends on the viewing direction. To this end, a rapid, one‐pot synthesis of copper‐based microclubs is developed that consists of a Cu2O octahedron attached to a Cu2O@Cu shaft. Millions of synthesized particles are analyzed in minutes with a FlowCam to provide a robust statistical analysis of their geometry, and rapidly elucidate the roles of the reaction constituents on the particle shape and yield. The combination of asymmetry in both shape and composition introduces a 30% difference in scattering of light propagating parallel to the microclub axis from opposing directions. This work represents a first step toward the creation of an asymmetric imaging environment with an aerosol consisting of acoustically aligned microclubs. [ABSTRACT FROM AUTHOR]

Future searches for new physics beyond the Standard Model are without doubt in need of a diverse approach and experiments with complementary sensitivities to different types of classes of models. One of the directions that should be explored is feebly interacting particles (FIPs) with masses below the electroweak scale. The interest in FIPs has significantly increased in the last ten years. Searches for FIPs at colliders have intrinsic limitations in the region they may probe, significantly restricting exploration of the mass range m FIP < 5 - 10 GeV/c 2 . Beam dump-like experiments, characterized by the possibility of extremely high luminosity at relatively high energies and the effective coverage of the production and decay acceptance, are the perfect option to generically explore the "coupling frontier" of the light FIPs. Several proposals for beam-dump detectors are currently being considered by CERN for implementation at the SPS ECN3 beam facility. In this paper, we analyse in depth how the characteristic geometric parameters of a beam dump experiment influence the signal yield. We apply an inclusive approach by considering the phenomenology of different types of FIPs. From the various production modes and kinematics, we demonstrate that the optimal layout that maximises the production and decay acceptance consists of a detector located on the beam-axis, at the shortest possible distance from the target defined by the systems required to suppress the beam-induced backgrounds. [ABSTRACT FROM AUTHOR]

The Future Circular hadron Collider (FCC-hh) is a proposed successor of the Large Hadron Collider (LHC). FCC-hh would push both the energy and intensity frontiers of searches for new physics particles. In particular, due to higher energy and luminosity than at the LHC, at FCC-hh there would be produced around ≃ 30 times larger amount of B mesons and ≃ 120 times of W bosons, which then may decay into feebly interacting particles. In this paper we demonstrate the potential of FCC-hh by studying its sensitivity to heavy neutral leptons (HNLs) with masses mN< mB. We consider various locations of a displaced decay volume embedded in the planned infrastructure of FCC-hh. We demonstrate that FCC-hh may substantially improve the reach of the parameter space of HNLs as compared to the searches proposed at the LHC. [ABSTRACT FROM AUTHOR]

SND@LHC is an approved experiment equipped to detect scatterings of neutrinos produced in the far-forward direction at the LHC, and aimed to measure their properties. In addition, the detector has a potential to search for new feebly interacting particles (FIPs) that may be produced in proton-proton collisions. In this paper, we discuss signatures of new physics at SND@LHC for two classes of particles: stable FIPs that may be detected via their scattering, and unstable FIPs that decay inside the detector. We estimate the sensitivity of SND@LHC to probe scatterings of leptophobic dark matter and decays of neutrino, scalar, and vector portal particles. Finally, we also compare and qualitatively analyze the potential of SND@LHC and FASER/FASERν experiments for these searches. [ABSTRACT FROM AUTHOR]

A wide gap between the increasing demand for organs and the limited supply leads to immeasurable loss of life each year. The organ shortage could be attenuated by donors with human immunodeficiency virus (HIV) or hepatitis C virus (HCV). The transplantation of organs from HIV+ deceased donors into HIV+ individuals (HIV D+ /R+) was initiated in South Africa in 2010; however, this practice was forbidden in the USA until the HIV Organ Policy Equity (HOPE) Act in 2013. HIV D+/R+ transplantation is now practiced in the USA as part of ongoing research studies, helping to reduce waiting times for all patients on the waitlist. The introduction of direct acting antivirals for HCV has revolutionized the utilization of donors with HCV for HCV-uninfected (HCV−) recipients. This is particularly relevant as the HCV donor pool has increased substantially in the context of the rise in deaths related to drug overdose from injection drug use. This article serves to review the current literature on using organs from donors with HIV or HCV. [ABSTRACT FROM AUTHOR]

During the COVID‐19 pandemic, there has been wide heterogeneity in the medical management of transplant recipients. We aimed to pragmatically capture immunosuppression practices globally following the early months of the pandemic. From June to September 2020, we surveyed 1267 physicians; 40.5% from 71 countries participated. Management decisions were made on a case‐by‐case basis by the majority (69.6%) of the programs. Overall, 76.8% performed ≥1 transplantation and many commented on avoiding high‐risk transplantations. For induction, 26.5% were less likely to give T‐cell depletion and 14.8% were more likely to give non‐depleting agents. These practices varied by program‐level factors more so than the COVID‐19 burden. In patients with mild, moderate and severe COVID‐19 symptoms 59.7%, 76.0%, and 79.5% decreased/stopped anti‐metabolites, 23.2%, 45.4%, and 68.2% decreased/stopped calcineurin inhibitors, and 25.7%, 43.9%, and 57.7% decreased/stopped mTOR inhibitors, respectively. Also, 2.1%, 30.6%, and 46.0% increased steroids in patients with mild, moderate, and severe COVID‐19 symptoms. For prevalent transplant recipients, some programs also reported decreasing/stopping steroids (1.8%), anti‐metabolites (10.3%), calcineurin inhibitors (4.1%), and mTOR inhibitors (5.5%). Transplant programs changed immunosuppression practices but also avoided high‐risk transplants and increased maintenance steroids. The long‐term ramifications of these practices remain to be seen as programs face the aftermath of the pandemic. [ABSTRACT FROM AUTHOR]

The extension of the Standard Model with two gauge-singlet Majorana fermions can simultaneously explain two beyond-the-Standard-model phenomena: neutrino masses and oscillations, as well as the origin of the matter-antimatter asymmetry in the Universe. The parameters of such a model are constrained by the neutrino oscillation data, direct accelerator searches, big bang nucleosynthesis, and requirement of successful baryogenesis. We show that their combination still leaves an allowed region in the parameter space below the kaon mass. This region can be probed by the further searches of NA62, DUNE, or SHiP experiments. [ABSTRACT FROM AUTHOR]

Mobile devices, climate science, and autonomous vehicles all require advanced microwave antennas for imaging, radar, and wireless communications. We propose a waveguide-fed metasurface antenna architecture that enables electronic beamsteering from a lightweight circuit board with varactor-tuned elements. Our approach uses a unique feed structure and layout that enables spatial sampling at the Nyquist limit of half a wavelength. We detail the design of this Nyquist metasurface antenna and experimentally demonstrate electronic beamsteering in two directions. Nyquist metasurface antennas can realize high performance without costly and power hungry phase shifters, making them a compelling technology for future antenna hardware. [ABSTRACT FROM AUTHOR]

In our first survey of transplant centers in March 2020, >75% of kidney and liver programs were either suspended or operating under restrictions. To safely resume transplantation, we must understand the evolving impact of COVID‐19 on transplant recipients and center‐level practices. We therefore conducted a six‐week follow‐up survey May 7‐15, 2020, and linked responses to the COVID‐19 incidence map, with a response rate of 84%. Suspension of live donor transplantation decreased from 72% in March to 30% in May for kidneys and from 68% to 52% for livers. Restrictions/suspension of deceased donor transplantation decreased from 84% to 58% for kidneys and from 73% to 42% for livers. Resuming transplantation at normal capacity was envisioned by 83% of programs by August 2020. Exclusively using local recovery teams for deceased donor procurement was reported by 28%. Respondents reported caring for a total of 1166 COVID‐19–positive transplant recipients; 25% were critically ill. Telemedicine challenges were reported by 81%. There was a lack of consensus regarding management of potential living donors or candidates with SARS‐CoV‐2. Our findings demonstrate persistent heterogeneity in center‐level response to COVID‐19 even as transplant activity resumes, making ongoing national data collection and real‐time analysis critical to inform best practices. [ABSTRACT FROM AUTHOR]

Traditional direct searches for dark matter, looking for nuclear recoils in deep underground detectors, are challenged by an almost complete loss of sensitivity for light dark matter particles. Consequently, there is a significant effort in the community to devise new methods and experiments to overcome these difficulties, constantly pushing the limits of the lowest dark matter mass that can be probed this way. From a model-building perspective, the scattering of sub-GeV dark matter on nucleons essentially must proceed via new light mediator particles, given that collider searches place extremely stringent bounds on contact-type interactions. Here we present an updated compilation of relevant limits for the case of a scalar mediator, including a new estimate of the near-future sensitivity of the NA62 experiment as well as a detailed evaluation of the model-specific limits from Big Bang nucleosynthesis. We also derive updated and more general limits on DM particles upscattered by cosmic rays, applicable to arbitrary energy- and momentum dependences of the scattering cross section. Finally we stress that dark matter self-interactions, when evaluated beyond the common s-wave approximation, place stringent limits independently of the dark matter production mechanism. These are, for the relevant parameter space, generically comparable to those that apply in the commonly studied freeze-out case. We conclude that the combination of existing (or expected) constraints from accelerators and astrophysics, combined with cosmological requirements, puts robust limits on the maximally possible nuclear scattering rate. In most regions of parameter space these are at least competitive with the best projected limits from currently planned direct detection experiments. [ABSTRACT FROM AUTHOR]

I Objective: i To describe antibody responses and vaccine reactions in recipients of solid organ transplants who had a suboptimal response to standard vaccination and subsequently received a third dose of vaccine between 20 March 2021 and 10 May 2021. I Background: i The antibody response after 2 doses of an mRNA vaccine against SARS-CoV-2 is excellent in the general population ([1]), but the response is different in recipients of solid organ transplants. It is encouraging that antibody titers increased after the third dose in one third of patients who had negative antibody titers and in all patients who had low-positive antibody titers. [Extracted from the article]

Rituximab has been associated with worse outcomes in patients with RMDs and SARS-CoV-2 infection ([5]), and thus it is of further concern that these patients may not derive protection from vaccination. I Background: i Patients with rheumatic and musculoskeletal diseases (RMDs) are at increased risk for SARS-CoV-2 infection because of both the immunomodulatory effects of their underlying diseases and treatment with immunosuppressive agents. Thus, we sought to analyze a subset of 20 patients with RMDs who did not develop a detectable antibody response 1 month after completion of 2-dose mRNA vaccination against SARS-CoV-2. [Extracted from the article]

This follow-up study measures the antibody response following the second dose of SARS-CoV-2 mRNA vaccine in recipients of solid organ transplants. [ABSTRACT FROM AUTHOR]

Abstract We consider the non-autonomous dynamical system { τ n } , where τ n is a continuous map X → X , and X is a compact metric space. We assume that { τ n } converges uniformly to τ. The inheritance of chaotic properties as well as topological entropy by τ from the sequence { τ n } has been studied in [4,5,10,13,17]. In [16] the generalization of SRB measures to non-autonomous systems has been considered. In this paper we study absolutely continuous invariant measures (acim) for non-autonomous systems. After generalizing the Krylov–Bogoliubov Theorem [7] and Straube's Theorem [14] to the non-autonomous setting, we prove that under certain conditions the limit map τ of a non-autonomous sequence of maps { τ n } with acims has an acim. [ABSTRACT FROM AUTHOR]

Abstract We review sterile neutrinos as possible Dark Matter candidates. After a short summary on the role of neutrinos in cosmology and particle physics, we give a comprehensive overview of the current status of the research on sterile neutrino Dark Matter. First we discuss the motivation and limits obtained through astrophysical observations. Second, we review different mechanisms of how sterile neutrino Dark Matter could have been produced in the early universe. Finally, we outline a selection of future laboratory searches for keV-scale sterile neutrinos, highlighting their experimental challenges and discovery potential. [ABSTRACT FROM AUTHOR]

This study quantifies antispike protein antibody responses to first-dose messenger RNA (mRNA) COVID-19 vaccines in solid organ transplant recipients to better understand the immunogenicity of the vaccines in immunocompromised individuals. [ABSTRACT FROM AUTHOR]

Axion-photon conversion is a prime mechanism to detect axion-like particles that share a coupling to the photon. We point out that in the vicinity of neutron stars with strong magnetic fields, magnetars, the effective photon mass receives comparable but opposite contributions from free electrons and the radiation field. This leads to an energy-dependent resonance condition for conversion that can be met for arbitrary light axions and leveraged when using systems with detected radio component. Using the magnetar SGR J1745-2900 as an exemplary source, we demonstrate that sensitivity to | g a γ | ∼ 10 − 12 Ge V − 1 or better can be gained for m a ≲ 10 − 6 eV , with the potential to improve current constraints on the axion-photon coupling by more than one order of magnitude over a broad mass range. With growing insights into the physical conditions of magnetospheres of magnetars, the method hosts the potential to become a serious competitor to future experiments such as ALPS-II and IAXO in the search for axion-like particles. [ABSTRACT FROM AUTHOR]

In 2013, the HIV Organ Policy Equity (HOPE) Act legalized transplantation of organs from donors infected with HIV to recipients infected with HIV. Despite similar estimates of the potential deceased donor pool, the number of actual donors with HIV has fallen short of the predicted numbers of HIV-infected donors. Outcome data for early studies on HIV-infected liver and kidney transplant recipients receiving HOPE donor organs are extremely encouraging. [Extracted from the article]

We investigate the use of a dynamic metasurface as the transmitting antenna for a synthetic aperture radar (SAR) imaging system. The dynamic metasurface consists of a 1-D microstrip waveguide with complementary electric resonator (cELC) elements patterned into the upper conductor. Integrated into each of the cELCs are two diodes that can be used to shift each cELC resonance out of band with an applied voltage. The aperture is designed to operate at K-band frequencies (17.5-20.3 GHz). We experimentally demonstrate imaging with a fabricated metasurface aperture using well-known SAR modalities, showing image quality comparable to traditional antennas. The agility of this aperture allows it to operate in spotlight and stripmap SAR modes, as well as in a third modality inspired by computational imaging strategies. We describe the dynamic metasurface antenna's operation in detail, demonstrate highquality imaging in both 2-D and 3-D, and examine various tradeoffs governing the integration of dynamic metasurfaces in the future SAR imaging platforms. [ABSTRACT FROM PUBLISHER]

Peer review is under pressure. Without fair, transparent and efficient peer review we cannot ensure the right proposals get funded and the correct manuscripts get published. In the era of Open Access, which is driving an exponential increase in the number of submitted publications, how we carry out peer review is becoming increasingly important and how we find reviewers is coming under scrutiny. The current methods are slow and produce bias pools of reviewers. As such we need an improved way. At Prophy we have developed a state-of-the-art referee finder that can find experts to review any manuscript from any scientific field in seconds. Then through post-processing filters we can find appropriate candidate referees who are most likely to review a paper, whilst highlighting important conflicts of interest through our complex citation networks. These methods can ensure fair and independent experts who can review interdisciplinary papers from any discipline. These methods are being delivered through APIs and the editorial workflow of editors ensure the right people get access to these tools. Finally, as large-language models improve, so does Prophy and as such we will be looking to drive real innovation in this area in years to come. [ABSTRACT FROM AUTHOR]

We re-analyse high redshift and high resolution Lyman- α forest spectra considered in [1] , seeking to constrain the properties of warm dark matter particles. Compared to this previous work, we consider a wider range of thermal histories of the intergalactic medium. We find that both warm and cold dark matter models can explain the cut-off observed in the flux power spectra of high-resolution observations equally well. This implies, however, very different thermal histories and underlying reionization models. We discuss how to remove this degeneracy. [ABSTRACT FROM AUTHOR]

Purpose: To report a series of 89 off-clamp laparoscopic partial nephrectomies (LPN) performed without using any additional "nephron sparing" manipulations. Methods: Retrospective analysis of surgical characteristics, complications, postoperative results, and renal function changes. Results: Between March 2008 and May 2014, 89 LPN using zero ischemia technique were performed. Most of the patients (61.8%) were male. The median age was 62 years (23-88). The mean BMI was 27.5 kg/m² (20.8-54.2). The median tumor size was 3.0 cm (1.0-8.0). Tumor location was upper, middle, and lower part of the kidney in 33 (37.0%), 42 (47.2%), and 14 (15.7%) of patients, respectively. The median operative time was 154 min (58-289). The median hemoglobin change was -1.6 g/dL (0.5-5.5). The transfusion rate was 7.9%. The mean preoperative glomerular filtration rate was 96.6 mL/min (21.5-180.0) with a mean postoperative decline of 6.52 mL/min. The mean creatinine elevation after LPN was 0.09 mg/dL. The median hospital stay was 6 days (2-24). The intraoperative complications rate was 2.3%. Early postoperative complication rate was 33.7%. Late complications occurred in 6.7%. In 7 cases (7.9%), the surgical margins were microscopically involved by tumor cells. Conversion rate was 3.4%. Conclusion: Data obtained in the current series show that laparoscopic partial nephrectomy can be successfully performed without hilar clamping. Our results are comparable with contemporary data. Larger prospective studies would be helpful in assessing the evidence-based advantages of the "zero ischemia" technique. [ABSTRACT FROM AUTHOR]

We report the results of the very large program with XMM-Newton (AO-14) devoted to deep observation of Draco dwarf spheroidal galaxy. The p-n junction (PN) camera shows a positive spectral feature at E =3.54±0.06 with a 2.3σ significance. The two Metal Oxide Semi-conductor (MOS) cameras show less-significant or no positive deviations, consistently within 1σ with PN. These results put the bound on the lifetime of a decaying dark matter particleτ >(7-9) × 1027 s at 95% CL. The spread in this result comes from the uncertainty in the column density of dark matter in the direction of Draco. This limit is consistent with dark matter interpretation of the 3.5 keV line observed in the stacked galaxy clusters, M31 and the galactic center within their 1-2σ uncertainties. [ABSTRACT FROM AUTHOR]

We consider a map of the unit square which is not 1-1, such as the memory map studied in Góra (Statistical and deterministic dynamics of maps with memory, ). Memory maps are defined as follows: $$x_{n+1}=M_{\alpha }(x_{n-1},x_{n})=\tau (\alpha \cdot x_{n}+(1-\alpha )\cdot x_{n-1}),$$ where $$\tau $$ is a one-dimensional map on $$I=[0,1]$$ and $$0<\alpha <1$$ determines how much memory is being used. In this paper we let $$\tau $$ to be the symmetric tent map. To study the dynamics of $$M_\alpha $$ , we consider the two-dimensional map The map $$G_\alpha $$ for $$\alpha \in (0,3/4]$$ was studied in Góra (Statistical and deterministic dynamics of maps with memory, ). In this paper we prove that for $$\alpha \in (3/4,1)$$ the map $$G_\alpha $$ admits a singular Sinai-Ruelle-Bowen measure. We do this by applying Rychlik's results for the Lozi map. However, unlike the Lozi map, the maps $$G_\alpha $$ are not invertible which creates complications that we are able to overcome. [ABSTRACT FROM AUTHOR]

We present results of a search for the 3.5 keV emission line in our recent very long (~ 1.4 Ms) XMM-Newton observation of the Draco dwarf spheroidal galaxy. The astrophysical X-ray emission from such dark matter-dominated galaxies is faint, thus they provide a test for the dark matter origin of the 3.5 keV line previously detected in other massive, but X-ray bright objects, such as galaxies and galaxy clusters. We do not detect a statistically significant emission line from Draco; this constrains the lifetime of a decaying dark matter particle to π >(7-9) × 1027 s at 95 per cent CL (combining all three XMM-Newton cameras; the interval corresponds to the uncertainty of the dark matter column density in the direction of Draco). The PN camera, which has the highest sensitivity of the three, does show a positive spectral residual (above the carefully modelled continuum) at E = 3.54 ± 0.06 keV with a 2.3σ significance. The two MOS cameras show less-significant or no positive deviations, consistently within 1σ with PN. Our Draco limit on π is consistent with previous detections in the stacked galaxy clusters, M31 and the Galactic Centre within their 1 - 2σ uncertainties, but is inconsistent with the high signal from the core of the Perseus cluster (which has itself been inconsistent with the rest of the detections). We conclude that this Draco observation does not exclude the dark matter interpretation of the 3.5 keV line in those objects. [ABSTRACT FROM AUTHOR]

We detect a line at 3.539 ± 0.011 keV in the deep exposure data set of the Galactic center region, observed with the x-ray multi-mirror mission Newton. The dark matter interpretation of the signal observed in the Perseus galaxy cluster, the Andromeda galaxy [A. Boyarsky et al., Phys. Rev. Lett. 113, 251301 (2014)], and in the stacked spectra of galaxy clusters [E. Bulbul et al., Astrophys. J. 789, 13 (2014)], together with nonobservation of the line in blank-sky data, put both lower and upper limits on the possible intensity of the line in the Galactic center data. Our result is consistent with these constraints for a class of Milky Way mass models, presented previously by observers, and would correspond to the radiative decay dark matter lifetime, tdm ~ 6 - 8 × 1027 sec. Although it is hard to exclude an astrophysical origin of this line based on the Galactic center data alone, this is an important consistency check of the hypothesis that encourages us to check it with more observational data that are expected by the end of 2015. [ABSTRACT FROM AUTHOR]

In many fields of geophysics and geodesy, it is required to know the deflection of the plumb line (PLD). With the airborne gravity measurements, by applying the gravimetric method, one can calculate the PLD in both the flat and mountainous terrain conditions. In the last case, the formulas for the calculations should include the correction for the effects of the topographic masses (the terrain correction). By using the method of S-approximations, which is based on representing the harmonic functions by the sum of the potentials of the simple and double layers on a certain support (e.g., on a horizontal plane), we have reconstructed the gravity field in each spatial point (at each measurement height), in particular, on the surface of the reference ellipsoid. We have developed the programs for computing the PLD by the Vening Meinesz formulas, which yield the zero approximation of PLD, and suggested the method for reconstructing the anomalous fields based on the S-approximations. The interpretation of the gravity data was also carried out by the method of R-approximations, which relies on the Radon transform. We present the results of the practical calculations for two regions of the Atlantic Ocean. [ABSTRACT FROM AUTHOR]

We report a weak line at 3.52 ± 0.02 keV in x-ray spectra of the Andromeda galaxy and the Perseus galaxy cluster observed by the metal-oxide-silicon (MOS) and p-n (PN) CCD cameras of the XMMNewton telescope. This line is not known as an atomic line in the spectra of galaxies or clusters. It becomes stronger towards the centers of the objects; is stronger for Perseus than for M31; is absent in the spectrum of a deep "blank sky" data set. Although for each object it is hard to exclude that the feature is due to an instrumental effect or an atomic line, it is consistent with the behavior of a dark matter decay line. Future (non-)detections of this line in multiple objects may help to reveal its nature. [ABSTRACT FROM AUTHOR]

Objectives—One-third of patients with untreated depression have sexual difficulties manifested by decreased libido, erectile dysfunction or delayed ejaculation. This dysfunction may be exacerbated by stimulation of post-synaptic serotonin 5HT2 receptors, a side-effect of most widely-used antidepressant medications, especially the selective serotonin reuptake inhibitors (SSRIs). Mirtazapine is an atypical antidepressant with a2 adrenergic antagonist and serotonin 5-HT2 and 5-HT3 receptor-blocking activity. In theory, it should not worsen and perhaps may improve sexual function. This pilot study investigated sexual functioning and antidepressant activity in depressed patients taking mirtazapine. Experimental design—Twenty-five (F = 18, M = 7) sexually active adult outpatients with a DSM-IV-diagnosis of major depressive episode entered a 12-week, flexible-dosing, open-label pilot study. The Arizona Sexual Experiences Scale (ASEX) assessed sexual functioning and the Hamilton Depression Rating Scale (HAM-D) assessed depressive symptoms on a bimonthly basis. Principal Observations—Desire, arousal/lubrication, and ease/satisfaction of orgasm improved (by 41%, 52%, and 48%, respectively) in the depressed women. In men, desire, arousal/erection, and ease/satisfaction of orgasm also improved (by 10%, 23% and 14%, respectively) but much more modestly. HAM-D, Clinical Global Impression (CGI) Sheehan Disability Scale (SDS), and Symptom Checklist-90 (SCL-90) scores improved in both groups. There was a 50% dropout rate among women before six weeks of treatment. However, the ASEX and HAM-D scores of the groups terminating before and after six weeks of treatment showed similar rates of improvement. Conclusions—Mirtazapine has a beneficial effect on sexual functioning in both depressed women and men. Longer-term double-blind research assessing sexual function during the administration of mirtazapine as well as other antidepressants is recommended. Depression and Anxiety 9:175–179, 1999. © 1999 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Let and let P be a partition of I into a finite number of intervals. Let , ; be two piecewise expanding maps on P. Let be the region between the boundaries of the graphs of and . Any map that takes values in G is called a selection of the multivalued map defined by G. There are many results devoted to the study of the existence of selections with specified topological properties. However, there are no results concerning the existence of selection with measure-theoretic properties. In this paper we prove the existence of selections which have absolutely continuous invariant measures (acim). By our assumptions we know that and possess acims preserving the distribution functions and . The main result shows that for any convex combination F of and we can find a map η with values between the graphs of and (that is, a selection) such that F is the η-invariant distribution function. Examples are presented. We also study the relationship of the dynamics of our multivalued maps to random maps. [Copyright &y& Elsevier]

OBJECTIVE: To investigate changes in pediatric kidney transplant outcomes over time and potential variations in these changes between the early and late posttransplant periods and across subgroups based on recipient, donor, and transplant characteristics. METHODS: Using multiple logistic regression and multivariable Cox models, graft and patient outcomes were analyzed in 17 446 pediatric kidney- only transplants performed in the United States between 1987 and 2012. RESULTS: Ten-year patient and graft survival rates were 90.5% and 60.2%, respectively, after transplantation in 2001, compared with 77.6% and 46.8% after transplantation in 1987. Primary nonfunction and delayed graft function occurred in 3.3% and 5.3%, respectively, of transplants performed in 2011, compared with 15.4% and 19.7% of those performed in 1987. Adjusted for recipient, donor, and transplant characteristics, these improvements corresponded to a 5% decreased hazard of graft loss, 5% decreased hazard of death, 10% decreased odds of primary nonfunction, and 5% decreased odds of delayed graft function with each more recent year of transplantation. Graft survival improvements were lower in adolescent and female recipients, those receiving pretransplant dialysis, and those with focal segmental glomerulosclerosis. Patient survival improvements were higher in those with elevated peak panel reactive antibody. Both patient and graft survival improvements were most pronounced in the first posttransplant year. CONCLUSIONS: Outcomes after pediatric kidney transplantation have improved dramatically over time for all recipient subgroups, especially for highly sensitized recipients. Most improvement in graft and patient survival has come in the first year after transplantation, highlighting the need for continued progress in long-term outcomes. [ABSTRACT FROM AUTHOR]

Dear editors, Among the many detrimental consequences of the COVID-19 pandemic to transplantation, the impact on the training experiences of residents/fellows has not been explored. 1 TableLikelihood of decline in transplant resident/fellow training experience during the pandemic rated on a scale of 1 to 5 (1 being unlikely and 5 being very likely) by transplant physicians. Transplant physicians from low- and middle-income countries rated the impact of the pandemic significantly greater than those from high-income countries. [Extracted from the article]

We model the innervation dynamics of interneurons in a cerebral cortex center A between the time of initial sensory input and acquisition of a sustained steady state. The model assumes that interneurons in A are heavily interconnected allowing synchronization. This invites modeling the dynamics by means of a discrete time map. The model takes into account the influence of excitatory and inhibitory cells and reflects the architecture of synapses along the axons. The acquisition of a sustained chaotic state is characterized by means of a natural invariant probability measure. The time to attain this probability measure can be estimated. [ABSTRACT FROM AUTHOR]

The article examines how the U.S. Supreme Court, via its decision in the 2013 court case, Penn Plaza LLC v. Pyett, has moved away from its 35 year precent against obliging employees to pursue their individual statutory claims in arbitration. The interpretation of the lower courts of the decision and the implications of the decision on future employer/union negotiations are detailed. Also discussed is the Court's decision in the court case, Alexander v. Gardner-Denver.

Galactic outflows driven by star formation and active galactic nuclei blow bubbles into their local environments, causing galactic magnetic fields to be carried into intergalactic space. We explore the redshift-dependent effect of these magnetized bubbles on the Faraday rotation measure (RM) of extragalactic radio sources. Using the IllustrisTNG cosmological simulations, we separate the contribution from magnetic bubbles from that of the volume-filling magnetic component expected to be due to the seed field originating in the early universe. We use this separation to extract the redshift dependence of each component and to compare IllustrisTNG model predictions with observation measurements of the NRAO VLA sky survey (NVSS). We find that magnetized bubbles provide a sizeable contribution to the extragalactic RM, with redshift-independent 〈|RM|〉 ≃ 13 rad/m2 for sources at redshifts z ≥ 2. This is close to the mean residual RM of 16 rad/m2 found from NVSS data in this redshift range. Using the IllustrisTNG simulations, we also evaluate a simple model for the contribution to residual RM from individual host galaxies and show that this contribution is negligible at high-redshift. While the contribution from magnetic bubbles in the IllustrisTNG model is currently compatible with observational measurements of residual RM, the next-generation RM sky surveys, which will be free from the wrapping uncertainty, have larger statistics and better sensitivity should be able to observe predicted flat contribution from magnetic bubbles at large redshifts. This should allow to experimentally probe magnetic bubbles and check models of galaxy feedback in cosmological simulations. [ABSTRACT FROM AUTHOR]

Metastable dynamical systems were recently studied [Gonzalez-Tokman et al, 2011] in the frame-work of one-dimensional piecewise expanding maps on two disjoint invariant sets, each possessing its own ergodic absolutely continuous invariant measure (acim). Under small deterministic per-turbations, holes between the two disjoint systems are created, and the two ergodic systems merge into one. The long term dynamics of the newly formed metastable system is defined by the unique acim on the combined ergodic sets. The main result of [Gonzalez-Tokman et al., 2011] proves that this combined acim can be approximated by a convex combination of the dis-joint acims with weights depending on the ratio of the respective measures of the holes. In this note we present an entirely different approach to metastable systems. We consider two piece-wise expanding maps: one is the original map, n, defined on two disjoint invariant sets of ℝN and the other is a deterministically perturbed version of T1, T2, which allows passage between the two disjoint invariant sets of T1. We model this system by a position dependent random map based on n and 72, to which we associate position dependent probabilities that reflect the switching between the maps. A typical orbit spends a long time in one of the ergodic sets but eventually switches to the other. Such behavior can be attributed to physical holes as between adjoining billiard tables or more abstract situations where balls can "leap" from one table to the other. Using results for random maps, a result similar to the one-dimensional main result of [González-Tokman et al., 2011] is proved in N dimensions. We also consider holes in more than two invariant sets. A number of examples are presented. [ABSTRACT FROM AUTHOR]

In thermal equilibrium the ground state of the plasma of Standard Model particles is determined by temperature and exactly conserved combinations of baryon and lepton numbers. We show that at nonzero values of the global charges a translation invariant and homogeneous state of the plasma becomes unstable and the system transits into a new equilibrium state, containing a large-scale magnetic field. The origin of this effect is the parity-breaking character of weak interactions and chiral anomaly. This situation could occur in the early Universe and may play an important role in its subsequent evolution. [ABSTRACT FROM AUTHOR]

The article assumes that strong cosmological magnetic fields (CMFs) are generated at a temperature ≳ 100 gigaelectronvolt (GeV). It demonstrates that the evolution of magnetic fields in a primordial plasma is strongly affected by the chiral anomaly. The authors also described the evolution of magnetic fields using the conventional magnetohydrodynamics (MHD).

Abstract: In the recent paper of Hooper and Goodenough (2010) it was reported that γ-ray emission from the Galactic Center region contains an excess compared to the contributions from the large-scale diffuse emission and known point sources. This excess was argued to be consistent with a signal from annihilation of Dark Matter with a power law density profile. We reanalyze the Fermi data and find instead that it is consistent with the “standard model” of diffuse emission and of known point sources. The main reason for the discrepancy with the interpretation of Hooper and Goodenough (2010) is different (as compared to the previous works) spectrum of the point source at the Galactic Center assumed by Hooper and Goodenough (2010) . We discuss possible reasons for such an interpretation. [Copyright &y& Elsevier]

Abstract: We suggest a new efficient way to constrain a certain class of large scale modifications of gravity. We show that the scale-free relation between density and size of dark matter halos, predicted within the ΛCDM model with Newtonian gravity, gets modified in a wide class of theories of modified gravity. [Copyright &y& Elsevier]

A signal from decaying dark matter (DM) can be unambiguously distinguished from spectral features of astrophysical or instrumental origin by studying its spatial distribution. We demonstrate this approach by examining the recent claim of Loewenstein and Kusenko regarding the possible DM origin of the 2.5 keV line in Chandra observations of the Milky Way satellite known as Willman 1. Our conservative strategy is to adopt, among reasonable mass estimates derived here and in the literature, a relatively large dark mass for Willman 1 and relatively small dark masses for the comparison objects. In light of the large uncertainty in the actual DM content of Willman 1, this strategy provides minimum exclusion limits on the DM origin of the reported signal. We analyse archival observations by XMM–Newton of M31 and Fornax dwarf spheroidal galaxy (dSph) and Chandra observations of Sculptor dSph. By performing a conservative analysis of X-ray spectra, we show the absence of a DM decay line with parameters consistent with those of Loewenstein and Kusenko. For M31, the observations of the regions between 10 and 20 kpc from the centre, where the uncertainties in the DM distribution are minimal, make a strong exclusion at the level above 10σ. The Fornax dSph provides a exclusion instead of a predicted 4σ detection, and the Sculptor dSph provides a 3σ exclusion instead of a predicted 2.5σ detection. The observations of the central region of M31 (1–3 kpc off-centre) are inconsistent with having a DM decay line at more than 20σ if one takes the most conservative among the best physically motivated models. The minimal estimate for the amount of DM in the central 40 kpc of M31 is provided by the model of Corbelli et al., assuming the stellar disc's mass to light ratio ∼8 and almost constant DM density within a core of 28 kpc. Even in this case one gets an exclusion at 5.7σ from central region of M31, whereas modelling all processed data from M31 and Fornax produces more than 14σ exclusion. Therefore, despite possible systematic uncertainties, we exclude the possibility that the spectral feature at ∼2.5 keV found in Loewenstein and Kusenko is a DM decay line. We conclude, however, that the search for DM decay line, although demanding prolonged (up to 1 Ms) observations of well-studied dSphs, M31 outskirts and other similar objects, is rather promising, as the nature of a possible signal can be checked. An (expected) non-observation of a DM decay signal in the planned observations of Willman 1 should not discourage further dedicated observations. [ABSTRACT FROM AUTHOR]

Abstract: In recent years an idea has emerged that a system in a 3-dimensional space can be described from an information point of view by a system on its 2-dimensional boundary. This mysterious correspondence is called the Holographic Principle and has had profound effects in string theory and our perception of space–time. In this note we describe a purely mathematical model of the Holographic Principle using ideas from nonlinear dynamical systems theory. We show that a random map on the surface of a 3-dimensional open ball B has a natural counterpart in B, and the two maps acting in different dimensional spaces have the same entropy. We can reverse this construction if we start with a special 3-dimensional map in B called a skew product. The key idea is to use the randomness, as imbedded in the parameter of the 2-dimensional random map, to define a third dimension. The main result shows that if we start with an arbitrary dynamical system in B with entropy E we can construct a random map on whose entropy is arbitrarily close to E. [Copyright &y& Elsevier]

Abstract: Many extensions of the Standard Model (SM) predict new neutral vector bosons at energies accessible by the Large Hadron Collider (LHC). We study an extension of the SM with new chiral fermions subject to non-trivial anomaly cancellations. If the new fermions have SM charges, but are too heavy to be created at LHC, and the SM fermions are not charged under the extra gauge field, one would expect that this new sector remains completely invisible at LHC. We show, however, that a non-trivial anomaly cancellation between the new heavy fermions may give rise to observable effects in the gauge boson sector that can be seen at the LHC and distinguished from backgrounds. [Copyright &y& Elsevier]

We present a comprehensive overview of an extension of the Standard Model that contains three right-handed (sterile) neutrinos with niasses below the electroweak scale [the Neutrino Minimal Standard Model (vMSM)l. We consider the history of the Universe from the inflationary era through today and demonstrate that most of the observed phenomena beyond the Standard Model can be explained within the framework of this model. We review the mechanism of baryon asymmetry of the Universe in the vMSM and discuss a dark matter candidate that can be warm or cold and that satisfies all existing constraints. From the viewpoint of particle physics, the model provides an explanation for neutrino flavor oscillations. Verification of the vMSM is possible with existing experimental techniques. [ABSTRACT FROM AUTHOR]

We consider dynamical systems on time domains that alternate between continuous time intervals and discrete time intervals. The dynamics on the continuous portions may represent species growth when there is population overlap and are governed by differential or partial differential equations. The dynamics across the discrete time intervals are governed by a chaotic map and may represent population growth which is seasonal. We study the long term dynamics of this combined system. We study various conditions on the continuous time dynamics and discrete time dynamics that produce chaos and alternatively nonchaos for the combined system. When the discrete system alone is chaotic we provide a condition on the continuous dynamical component such that the combined system behaves chaotically. We also provide a condition that ensures that if the discrete time system has an absolutely continuous invariant measure so will the combined system. An example based on the logistic continuous time and logistic discrete time component is worked out. [ABSTRACT FROM AUTHOR]