SWAP and Fredkin gates for OAM optical beams via the sandwich of anisotropic optical fibers.

We study the propagation of circularly-polarized optical vortices of higher order topological charges ℓ ≥ 2 in a sandwich of multihelical - anisotropic - multihelical fibers on the basis of the Jones formalism for modes with orbital angular momentum. We demonstrate that such a system can operate as the all - fiber two - bit SWAP as well as universal tree - bit controlled-SWAP (Fredkin) gates over states of optical vortices, in which the mode radial number carries the control bit, while circular polarization and topological charge are the controlled bits.

Effects of flexible scheduling and virtual visits on burnout for clinicians.

OBJECTIVE: Burnout is a healthcare quality problem, linked to negative impacts in patient care and healthcare providers. The pandemic prompted clinicians to adapt virtual practices and adopt more flexible, autonomous schedules. However, the impact of flexible scheduling and autonomy on provider burnout is unknown. The study aim was to evaluate the effect of flexible schedules versus standard schedules, and the amount of digital care, on burnout. METHODS: This was a prospective survey study at two time points 6 months apart. Providers from Rheumatology, Neurology, and Pediatrics completed surveys at baseline, between 6/22/2020-9/8/2020, and six months later, between 12/20/20-3/12/21. The primary outcome was the Mini-Z work life survey which measured burnout in 2 different groups: flexible schedules (FS) and standard schedules (SS) during the height of the pandemic. RESULTS: The study included 149 providers, 47 with FS and 102 with SS, who completed the survey at baseline and 6 months later. At baseline providers reported high job satisfaction (85.9%) and low burnout (29.7%), which remained consistent at 6 months. Compared to those with SS, clinicians with FS participated in a greater number of telemedicine activities at baseline, but did not differ significantly in degree of burnout (25.5% FS, 31.7% SS, p=0.45). Participants in the FS group were significantly more likely to indicate improvement in control over workload and experience reduced work-related stress compared to those in the SS group. There was no association between amount of telemedicine visits and burnout. Predictors of burnout at 6 months included Rheumatology providers and those in the 20-39 year old age group. DISCUSSION: Schedule flexibility does not appear to influence overall burnout; however it does impact variables associated with burnout such as control over workload and perceived job stress. CONCLUSIONS: Participants reported overall job satisfaction, and FS did not impact overall burnout. FS was more likely to indicate improvement in control over workload and experienced reduced work-related stress compared to SS. In addition, burnout was more likely in the 20-39 year old age group, suggesting that special focus should be paid to this age group.

An empirically based proposal to identify a short battery to detect neuropsychological impairment in a general adult practice.

Objectives: To demonstrate that 1) models based on small numbers of tests can be statistically developed to identify neuropsychological impairment in a general adult neuropsychology clinic and 2) those models show strong predictive validity on replication in a slightly different sample. Method: Latent Class Analyses (LCA) were used to determine neuropsychological classification in 231 patients referred to general adult neuropsychology services. A clinical rating scale was also used to approximate clinical decision-making. Regression models were constructed in a training sample (n = 127) drawn from an adult neuropsychology clinic using test scores from seven different a priori test battery combinations to predict group membership or clinical rating. The utility of the seven models was assessed in a testing sample (n = 104) from another independent adult neuropsychology clinic. Results: The LCA yielded a two class solution characterized by impaired versus non-impaired performance on neuropsychological tests. A seven test battery provided the best balance of accuracy and length in predicting LCA group with a sensitivity of 84.4% and a specificity of 90%. Sensitivity and specificity were slightly attenuated using the clinical rating scale as the criterion, but the seven test battery still provided good accuracy (AUC=.906). Conclusions: Test protocols based on only five to eight test scores can accurately identify most patients with clinical impairment in a diverse adult neuropsychology clinic. Development of short protocols with adequate sensitivity and specificity will become increasingly important to address long waiting lists in light of the COVID pandemic against the general backdrop of increasing demand for neuropsychological services.

Generation of optical vortices in non-parity-time-symmetric chiral-core optical fibers.

In this Letter, we have studied the effect of losses and gains on generation of optical vortices (OVs) in a chiral fiber with an l-fold rotational symmetric core. Studying both unequal attenuations and symmetric loss-gain cases for core and orbital angular momentum (OAM) modes, we show that losses may play a constructive role in generation of OVs from a Gaussian input. We study the processes of field evolution at the exceptional point (EP). We show that at the EP any superposition of the fundamental mode and l-charge OV evolves in the limit into an equal-weighted superposition of such fields that forms a special attractor mode with average l/2 OAM per photon. At the generalized Poincare sphere, such a mode is represented by the OAM black hole in analogy with the spin black hole introduced in [Optica3, 1025 (2016)OPTIC82334-253610.1364/OPTICA.3.001025].

Optical vortices and orbital angular momentum in strongly coupled optical fibers.

We have studied the effect of strong coupling on the propagation of optical vortices (OVs) and evolution of their orbital angular momentum (OAM) in parallel multimode optical fibers. Based on the perturbation theory that goes beyond the limits of weak orthogonality approximation we have established that strong coupling does not lead to alteration of the structure of supermodes as compared to the case of weak coupling. The strong coupling affects only the propagation constants of such supermodes, which we have found analytical expressions for. We have also studied the evolution of OVs and emphasized the difference between the powers stored in partial OVs and powers located at the fiber cores. We have studied OAM in such fibers, as well as corrections to the total OAM due to interference effects and shown that the influence of such effects on forming the total OAM under strong coupling is negligible. We have also demonstrated that in such systems it is sufficient to take account only of the coupling of OVs with equal by modulus topological charges, whereas other types of coupling are negligible.

Amplification of optical activity in a fiber loop resonator.

In this paper, we have theoretically studied an effective amplification of optical activity by a fiber loop resonator. We propose a scheme in which an optically active element is placed in the loop segment of the resonator. Assuming that the coupling in the resonator is polarization-independent, we have shown that initially small polarization plane rotation, which arises due to the optically active element, can be significantly amplified by tuning the resonator's closed-path phase. We have also studied the influence of losses on the amplification of optical activity. We have shown that the maximal amplification takes place under the condition of critical coupling, at which the attenuation parameter is equal to the resonator's effective reflection coefficient. We have also studied effective dichroism in such a system and shown the relevance of a critical coupling regime to that effect.

Formation of Alcohol Motivation in Monkeys (Macaca mulatta) Kept in Isolation.

The effects of environmental factors (flavors, different ethanol concentration, alcoholic deprivation, and food reinforcement) on the formation of alcohol motivation was studied in rhesus macaques (Macaca mulatta, n=6). Motivation for alcohol intake was induced in two stages: initiation (sessions 1-160) and formation of motivation (sessions 161-516). Monkeys preferred multifruit flavor and 4% ethanol solution, while ethanol deprivation did not stimulate alcohol consumption. The pronounced individual differences in the pattern of alcohol motivation were revealed: the intake of 4% ethanol solution ranged from 0.21±0.03 to 0.43±0.06 g/kg without food reinforcement and increased from 0.78±0.03 to 1.22±0.09 g/kg with food reinforcement. The results suggest that the proposed method is valid and can be used as an experimental model of alcohol dependence in non-human primates.

Transmission of optical vortices through fiber loop resonators.

In this Letter, we study the propagation of optical vortices (OVs) through the loop resonator (LR) on a multimode fiber. We demonstrate the existence of a special resonance, which is in the inversion of the topological charge of the transmitted OV. Near the resonance, the output orbital angular momentum (OAM) is sensitive to wavelength-scale variations of the LR's optical path length, which can be used for super-efficient OAM control. We also show the feasibility of a combined wavelength and OAM division multiplexing in comb filters on such LRs.

Natural infection of captive cynomolgus monkeys (Macaca fascicularis) with hepatitis E virus genotype 4.

Data on natural HEV infection of infection in monkeys are limited. We report a case of hepatitis E virus genotype 4 infection in captive non-human primates (cynomolgus monkeys) imported from Vietnam. Phylogenetic analysis demonstrated that HEV infection was not the result of spillover from single source of infection, but rather the persistent circulation of HEV-4 among cynomolgus monkeys or multiple infections by related strains from a human or swine reservoir.

Water Immersion as a Model of Hypogravity.

We studied the effects of hypogravity modeled by water immersion on cognitive functions and physiological parameters of monkeys. Cognitive capacities of monkeys were evaluated using computer-controlled joystick task with food reward in case of target hit. Water immersion (3 days for 3 h) affected in cognitive functions, body temperature, and blood parameters. The intensity of changes depended on the type of monkey behavior. In animals with non-aggressive behavior, the number of target hits did not decrease after water immersion, and even slightly increased. On the contrary, aggressive monkeys showed poorer test performance. Body temperature after each cycle of water immersion was decreased slightly in non-aggressive monkeys, while in aggressive animals, the changes were significant. At the same time, changes in the erythrocyte count, hemoglobin concentration, and hematocrit were significant in non-aggressive monkeys. Our results are in line with previous data performed on BION biosatellites and correspond to changes of physiological parameters in astronauts during space flights.

Revised model of acousto-optic interaction in optical fibers endowed with a flexural wave.

We propose a novel model of the acousto-optic interaction in circular fibers endowed with the lowest-order flexural acoustic wave that is based on the actual distribution of the acoustically induced displacement vector. The corresponding expression for the fiber's permittivity is derived and compared with the commonly used one. The resonance optical fiber modes and the propagation constants are found. It is predicted that the lengths of the well-known acoustically driven mode conversion LP0,n→LP1,n' should be slightly different for the x- and y-polarized incident fundamental modes. Moreover, we unveil a new polarization-dependent mode conversion in which the azimuthal mode number ℓ, as well as the optical frequency of the generated standard fiber mode LPℓ,n' , is governed by the linear polarization direction of the incident zero-order beam LP0,n.

[Markers of hepatitis A in the monkeys of the Adlers primate center.]

Hepatitis A is a widespread viral infection. The HAV strains of "human" and "monkey" origin are similar in their morphological and antigenic properties, but differ genotypically. OBJECTIVES: The aim of this research was a comparative study of serological and molecular-genetic markers of HAV infection in monkeys born at the Adler Primate Center and in those imported from different countries. MATERIAL AND METHODS: Fecal samples (n = 313) and serum (n = 266) from various species of monkey using ELISA and RT-PCR were studied. RESULTS AND DISCUSSION: The frequency of anti-HAV-IgG was high (78.9%) in imported animals (vervet monkeys from Tanzania and cynomolgus monkeys from Vietnam) and as well as in various species of monkeys (rhesus monkeys, cynomolgus monkeys, green monkeys and papio hamadryas) of the Center (88.6%). At the same time, in the imported monkeys, the markers of "fresh" HAV infection (IgM-27.2%, Ag-HAV-16.7%, RNA-22.0%) were detected significantly more often (p> 0.05) than in monkeys kept at the Colony (IgM-7.5%, HAV-Ag - 5.2%, RNA - 3.6%). In general, anti-IgG reactivity ranged from 1.064 to 2.073 OD450, anti-IgM ranged from 0.546 to 1.059 OD450. The number of HAV-Ag was 0.496 - 1.995 OD450. RNA HAV only in rhesus monkeys and cynomolgys monkeys born at the Colony, as well as in imported vervet monkeys was detected. CONCLUSIONS: The data obtained indicate a wide circulation of HAV among monkeys born in the Adler Primate Center and among the imported animals. Markers of "fresh" HAV infection varied depending on the species of monkeys and their origin.

Development of a motor and somatosensory evoked potentials-guided spinal cord Injury model in non-human primates.

Background Nonhuman primates (NHP) may provide the most adequate (in terms of neuroanatomy and neurophysiology) model of spinal cord injury (SCI) for testing regenerative therapies, but bioethical considerations exclude their use in severe SCI. New Method A reproducible model of SCI at the lower thoracic level has been developed in Rhesus macaques. The model comprises surgical resection of 25% of the spinal cord in the projection of the dorsal funiculus and dorsolateral corticospinal pathways, controlled via registration of intraoperative evoked potentials (EPs). The animals were evaluated using the modified Hindlimb score, MRI, SSEP, and MEP over a time period of 8-12 weeks post-SCI, followed by histological examination. Results Complete disappearance of intraoperative EPs from distal hindlimb muscles without restoration within two weeks post-SCI was an indicator for irreversible disruption of the abovementioned pathways. As a result, controlled damage to the spinal cord was achieved in three NHPs, clinically manifested as irreversible lower monoplegia. No significant functional restoration was observed in these NHPs up to 12 weeks post-SCI. Demyelination of the damaged ascending tracts was detected. Disturbances in pelvic organ function were not observed in all animals. Comparison with existing methods The new method of EPs-guided SCI allows a more controlled and irreversible damage to the spinal cord compared with contusion and other transection approaches. Conclusions This method to induce complete SCI in NHP is well tolerated, reproducible and ethically acceptable: these are valuable attributes in a preclinical model that will hopefully help advance testing of new regenerative therapies in SCI.

Functional Parameters of Physiological Systems of Laboratory Primates after Administration of Doxorubicin and Transplantation of Mesenchymal Stem Cells.

We studied physiological parameters of rhesus monkeys after administration of anthracycline antibiotic doxorubicin. Intravenous administration of the drug caused intoxication manifested in in an abrupt body weight loss, baldness, vomiting, and exicosis. Intoxication in monkeys determined by the damaging effects of doxorubicin on organs and tissues is also characterized by significant changes in the blood: leukopenia, thrombocytopenia, neutropenia, monocytopenia, lymphocytosis, and a sharp drop of CD20+ B cell content. The total protein and albumin content in the blood significantly decreased. A sharp increase in C-reactive protein was also accompanied by an increase in activity of proinflammatory cytokine IL-6. Transplantation of mesenchymal stem cells in some cases can significantly alleviate doxorubicin-induced damage to organs and maintain normal clinical status of monkeys after two injections of the drug. Late transplantation of stem cells does not have a protective effect and does not protect the animals from the damaging effects of doxorubicin. We found that the protective effect of mesenchymal stem cells depends on the dose of the drug, total number of cells, and the time of their transplantation. It should be noted that human and monkey mesenchymal stem cells produce similar regenerative effects, at least in the doxorubicin toxicity model.

Use of Mesenchymal Stem Cells for Possible Repair of Doxorubicin-Damaged Organs and Tissues in Experimental Monkeys.

Three injections of doxorubicin to rhesus macaques cause severe intoxication, characterized by anemia, cachexia, and degeneration of the viscera. The life span of monkeys injected with the drug and receiving after 24 h mesenchymal stem cell transplantation varied from 96 to 120 days in comparison with 50-74 days in animals receiving stem cells before doxorubicin. Controls received doxorubicin and saline; the lifespan of one monkey was 24 days, of the other - 1 year and 8 months. The increase in activity of proinflammatory cytokine IL-6 was paralleled by an increase in the level of C-reactive protein.

In Vivo Experimental Study of Biological Compatibility of Tissue Engineered Tracheal Construct in Laboratory Primates.

Biological compatibility of a tissue engineered construct of the trachea (synthetic scaffold) and allogenic mesenchymal stem cells was studied on laboratory Papio hamadryas primates. Subcutaneous implantation and orthotopic transplantations of tissue engineered constructs were carried out. Histological studies of the construct showed chaotically located filaments and mononuclear cells fixed to them. Development of a fine connective tissue capsule was found at the site of subcutaneous implantation of the tissue engineered construct. The intact structure of the scaffold populated by various cell types in orthotopic specimens was confirmed by expression of specific proteins. The results indicated biological compatibility of the tissue engineered construct with the mesenchymal stem cells; no tissue rejection reactions were recorded; simulation of respiratory disease therapy on Papio hamadryas proved to be an adequate model.

Food security is related to adult type 2 diabetes control over time in a United States safety net primary care clinic population.

BACKGROUND/OBJECTIVES: Successful Type 2 diabetes management requires adopting a high nutrient-density diet made up of food items that both meet dietary needs and preferences and can be feasibly obtained on a regular basis. However, access to affordable, nutrient-dense foods often is lacking in poorer neighbourhoods. Therefore, low food security should directly impair glucose control, even when patients have full access to and utilize comprehensive medical management. The present study sought to determine whether food security is related longitudinally to glucose control, over-and-above ongoing medication management, among Type 2 diabetes patients receiving comprehensive care at a Midwestern multi-site federally qualified health centre (FQHC). SUBJECTS/METHODS: In this longitudinal observational study, we completed a baseline assessment of patients' food security (using the US Household Food Security Module), demographics (via Census items), and diabetes history/management (using a structured clinical encounter form) when patients began receiving diabetes care at the health centre. We then recorded those patients' A1C levels several times during a 24-month follow-up period. Three hundred and ninety-nine patients (56% with low food security) had a baseline A1c measurement; a subsample of 336 (median age=52 years; 56% female; 60% Hispanic, 27% African American, and 9% White) also had at least one follow-up A1c measurement. RESULTS: Patients with lower (vs higher) food security were more likely to be on insulin and have higher A1c levels at baseline. Moreover, the disparity in glucose control by food security status persisted throughout the next 2 years. CONCLUSIONS: Although results were based on one multi-site FQHC, potentially limiting their generalizability, they seem to suggest that among Type 2 diabetes patients, low food security directly impairs glucose control-even when patients receive full access to comprehensive medical management-thereby increasing their long-term risks of high morbidity, early mortality, and high health-care utilization and cost.

Resonance optical activity in multihelicoidal optical fibers.

We have studied the effect of optical activity (OA) in optical fibers with multihelical distribution of refractive index profiles near the resonance wavelength, at which the conversion of an incident Gaussian beam into an optical vortex (and vice versa) takes place. We have shown that at such a wavelength the polarization vector of the input Gaussian beam rotates within the fiber at an average rate proportional to the difference in propagation constants of left- and right-circularly polarized optical vortices with the same topological charge. We also show that for certain fiber lengths the magnitude of OA can greatly exceed its average level and reach anomalously high values.

Transplantation of Simian Mesenchymal Stem Cells to Baboons with Experimentally Induced Myocardial Infarction.

Culture of mesenchymal stem cells isolated from the bone marrow of primates by their characteristics met the requirements of stem cells. It was shown that transplantation of allogeneic mesenchymal stem cells (2 million cells per 1 kg body weight) immediately after ligation of the left anterior descending coronary artery between the middle and upper thirds led to neovascularization and capillarization of the ischemic myocardium.