Human oocytes and zygotes are ready for ultra-fast vitrification after 2 minutes of exposure to standard CPA solutions

Vitrification of human oocytes and embryos in different stages of development is a key element of daily clinical practice of in vitro fertilization treatments. Despite the cooling and warming of the cells is ultra-fast, the procedure as a whole is time consuming. Most of the duration is employed in a long (8–15 minutes), gradual or direct exposure to a non-vitrifying cryoprotectant solution, which is followed by a short exposure to a more concentrated vitrifying solution. A reduction in the duration of the protocols is desirable to improve the workflow in the IVF setting and reduce the time of exposure to suboptimal temperature and osmolarity, as well as potentially toxic cryoprotectants. In this work it is shown that this reduction is feasible. In silico (MatLab program using two-parameter permeability model) and in vitro observations of the oocytes’ osmotic behaviour indicate that the dehydration upon exposure to standard cryoprotectant solutions occurs very fast: the point of minimum volume of the shrink-swell curve is reached within 60 seconds. At that point, intracellular water ejection is complete, which coupled with the permeation of low molecular weight cryoprotectants results in similar intracellular and extracellular solute concentrations. This shows that prolonging the exposure to the cryoprotectant solutions does not improve the cytosolic glass forming tendency and could be avoided. To test this finding, human oocytes and zygotes that were donated for research were subjected to a shortened, dehydration-based protocol, consisting of two consecutive exposures of one-minute to two standard cryoprotectant solutions, containing ethylene glycol, dimethyl sulfoxide and sucrose. At the end of this two-minute dehydration protocol, the critical intracellular solute concentration necessary for successful vitrification was attained, confirmed by the post-warming survival and ability to resume cytokinesis of the cells. Further studies of the developmental competency of oocytes and embryos would be necessary to determine the suitability of this specific dehydration protocol for clinical practice, but based on our results, short times of exposure to increasingly hypertonic solutions could be a more time-efficient strategy to prepare human oocytes and embryos for vitrification

Scaled solar tracks and isochrones in a large region of the Z-Y plane. II. From 2.5 to 20 solar masses

We extend our theoretical computations for low-mass stars to intermediate-mass and massive stars, for which few databases exist in the literature. Evolutionary tracks and isochrones are computed from 2.50 to 20 solar masses for agrid of 37 chemical compositions with metal content Z between 0.0001 and 0.070 and helium content Y between 0.23 and 0.40. Synthetic TP-AGB models allow stellar tracks and isochrones to be extended until the end of the thermal pulses along the AGB. We provide software tools for the bidimensional interpolation (in Y and Z) of the isochrones. We present tracks for scaled-solar abundances and the corresponding isochrones from very old ages down to about 10 million years. The extension of the blue loops and the instability strip of Cepheid stars are compared and the Cepheid mass-discrepancy is discussed. The location of red supergiants in the H-R diagram is in good agreement with the evolutionary tracks for masses from 10 to 20 solar masses. Tracks and isochrones are available in tabular form for the adopted grid of chemical compositions in the extended plane Z-Y in three photometric systems. An interactive web interface allows users to obtain isochrones of any chemical composition inside the provided Z-Y range and also to simulate stellar populations with different Y(Z) helium-to-metal enrichment laws.Comment: 17 pages, 18 figures, accepted for publication in A&

GARFIELD + RCo Digital Upgrade: a Modern Set-up for Mass and Charge Identification of Heavy Ion Reaction Products

An upgraded GARFIELD + Ring Counter (RCo) apparatus is presented with improved performances as far as electronics and detectors are concerned. On one side fast sampling digital read out has been extended to all detectors, allowing for an important simplification of the signal processing chain together with an enriched extracted information. On the other side a relevant improvement has been made in the forward part of the setup (RCo): an increased granularity of the CsI(Tl) crystals and a higher homogeneity in the silicon detector resistivity. The renewed performances of the GARFIELD + RCo array make it suitable for nuclear reaction measurements both with stable and with Radioactive Ion Beams (RIB), like the ones foreseen for the SPES facility, where the Physics of Isospin can be studied.Comment: 13 pages, 19 figures - paper submitted to Eur. Phys. J.

Experimental effects on dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4π\pi detector

Heavy ion collisions have been widely used in the last decade to constraint the parameterizations of the symmetry energy term of nuclear equation of state (EOS) for asymmetric nuclear matter as a function of baryonic density. In the Fermi energy domain one is faced with variations of the density within a narrow range of values around the saturation density $\rho_0$=0.16 fm$^{-3}$ down towards sub-saturation densities. The experimental observables which are sensitive to the symmetry energy are constructed starting from the detected light particles, clusters and heavy fragments that, in heavy ion collisions, are generally produced by different emission mechanisms at different stages and time scales of the reaction. In this review the effects of dynamics and thermodynamics on the symmetry energy in nuclear reactions are discussed and characterized using an overview of the data taken so far with the CHIMERA multi-detector array.Comment: 21 pages, 25 figures. Review to appear in EPJA special volume on nuclear symmetry energ

Culturally-Adapted Cognitive Behavioral Therapy for Bilingual Latinx with Depressive Symptoms

The prevalence of depression is particularly high in the Latinx population, and this population is associated with lower rates of depression diagnosis and treatment. One intervention that has shown to be effective in treating mild to moderate depression is cognitive behavioral therapy. Though the effects of culturally adapted therapy, language being the most common adaptation, have been studied, the difference in outcomes for bilingual, bicultural speakers has not been examined. In this randomized control trial, we will compare the effectiveness of Spanish language cognitive behavioral therapy to that of English language therapy in bilingual, foreign-born, Latinx patients with depressive symptoms. We expect patients will have a statistically significant difference from baseline in their depressive symptoms at six months with S-CBT. This work may help improve access to effective care for depressive symptoms in this population and may suggest broader use of “native-language therapy” to improve outcomes

PREDICTORS OF ACCULTURATIVE STRESS FOR INTERNATIONAL STUDENTS IN THE UNITED STATES

International students in the United States are confronted with a wide range of challenges and difficulties as they move to a new country and need to adapt to a new cultural, social, andacademic environment. This study examined the relationship between acculturation orientation, or how these cultural changes are addressed, sources of social support, and the level of acculturative stress these students experience. Data was collected using an on-line survey from international students at six public universities in Missouri, Oklahoma, Texas, and Iowa. Statistical analysis was conducted on the data collected from the 648 students who participated in the study. Descriptive statistics, group comparisons, and a regression model were employed to summarize and test the study’s hypotheses. Correlational analysis indicated that lower levels of acculturative stress were associated with both positive cultural identification with both the home and host culture, as well as the presence of a wide network of social support, while increased levels of acculturative stress were found to be related primarily to higher levels of perceived discrimination and higher levels of mood and anxiety disturbances. Analysis of group differences found that students with positive home and host cultural identifications, as well as students with broad-based social support, experienced statistically significant lower levels of acculturative stress than other groups. A prediction model was developed, although only perceived level of English language ability, perceived discrimination, levels of mood and anxiety disturbance, positive host culture identification, and host country social support were found to be statistically significant predictors. The study findings highlight the importance of both positive cultural identification with both the home and host culture, as well as the positive association with higher levels of social support on mitigating the level of acculturative stress international students experience. The findings have implications for mental health professionals counseling international students in the United States to better understand and thereby develop more effective therapeutic interventions in their work with international students. Suggestions for future research are also indicated

Stiffness and Compliance of Kinematic Chains in Motion

The main aim of this thesis is the analysis of bioinspired kinematic chains controllable both in position and compliance (or stiffness) from a static and a dynamic point of view. In motion control theory, the redundancy of muscles, with respect to the number of degrees of freedom in a typical biomechanical system, permits the formulation of several control strategies. In this work the Feldman quadratic muscular model, proposing a direct connection between the magnitude and the frequency of sub-cortical electrical stimuli and muscular co-activation, is adopted. Two new indicators, the Dynamic Stiffness and Compliance Operators, are defined in a mathematical way by the use of functional analysis. These new indicators allow a theoretical and practical study of the performance of a chain during collisions or under external perturbations. The Dynamic Stiffness Operators can be useful in the treatment of many mechanical problems, as, for example, the estimation of the force generated by the system when it commits an error in terms of its trajectory, fundamental in breakable object manipulation. Instead, the Dynamic Compliance Operator, measuring the deviation from a given trajectory in presence of external perturbations, is defined as the inverse of the Stiffness Operator and is very more complex to calculate explicitly. In order to perform this calculation many mathematical instruments are used. Finally the mathematical theory developed in the thesis is applied to the design of electroactive polymer fiber bundles driven by bioinspired control variables to implement pseudomuscular actuators devoted to the realization of biomimetic movements

A model for fermionic dark matter addressing both the CDF M W and the (g − 2)μ anomalies

We explore a simple and renormalizable model which incorporates a new stable fermion that accounts for the dark matter in the universe and which, at the same time, provides an interpretation of two recent measurements that deviate from the expectation in the Standard Model: the muon anomalous magnetic moment and the mass of the W boson recently recorded by the CDF collaboration. The model has a fermionic sector that involves singlet and doublet fields, in which the lightest state is the DM and interacts mainly through the Higgs portal. Two realizations of such a possibility are considered: one in which the Higgs sector is minimal and another in which it is extended to contain two doublet fields.Estonian Research Council (ERC) MOBTT86Junta de Andalucia PID2021-128396NB-I00, A-FQM-211-UGR18, P18-FR-4314European Commissio