Assisted reproductive technology: perceptions and behaviours in Guatemala before and during the Covid-19 pandemic

Infertility is a challenge many people presently face and will continue to face in the future around the world. Conceiving can present several psychosocial challenges and obstacles in Western and non-Western countries. Two ethnic groups in Guatemala (a non- Western country), namely The Maya1 and Ladino (Maya n = 35, 11 males 14 females, mean age = 27.3, Sd = 7, and Ladino n = 146, 58 males and 88 females, mean age = 29.2, Sd = 10.3) were investigated on the perceptions and behaviour towards Assisted Reproductive Technology (ART) (study 1). The study was conducted a few months before the outbreak of the Covid-19 pandemic. A 13-statement questionnaire e.g., “children born by ART may be socially withdrawn” was presented to the participants to rate on a Likert scale, ranging from 1 = Strongly Agree to 5 = Strongly Disagree. Furthermore, participants were instructed to justify their response by making written comments and rating their level of knowledge about ART on a scale 1 = not at all to 10 = a considerable amount. Half of the participants rated their level of knowledge before reading the questionnaire items, the other half after reading the questionnaire items. Demographic information and factors namely, age, gender, religion, education and knowing someone undergoing ART were also recorded. Data collection took six months to complete (April to September of 2019). Data was subjected to Principal Components Analysis followed by Stepwise Regression, Factorial Anova and Correlational analyses. Written responses (219 from The Maya and 931 from Ladinos) were subjected to Thematic Analysis (TA). The results generally showed that religion, social acceptance, trust in modern medicine, gender, and ethnicity play an important role in Guatemalan populations’ perceptions and behaviour towards ART. The results of study 1 was supported by findings of key medical fertility practitioners in Guatemala (study 2) and in the UK (study 3), two single case studies. The two single case studies also extended to investigate if Covid-19 will, or has already, had an impact on study 1 findings and patients’ perception and behaviour towards ART. Findings from studies 2 and 3 via the application of Interpretative Phenomenological Analysis (IPA), mirrored study 1 findings to a large extent on secrecy, racial integration issues, religion, and risk factors. Both practitioners in Guatemala and the UK indicated that since Covid-19 there are new concerns about risks involved regarding ART treatment. Study 4 was a Scope literature review (between the period of 2020-2021) of the impact of Covid-19 and possible changes in behaviour of patients involved in ART treatment. The results indicated an overall distress caused by the Covid-19 pandemic and the worries triggered when undergoing infertility treatments during this very difficult time. The importance of continuing infertility treatment during the Covid-19 pandemic was also a factor in the findings. These findings also illuminate that if treatments were to stop, it would be detrimental to patients and the scientific community. In general, these findings have significant implications for the scientific community as the data was collected before and during the outbreak of the Covid-19 pandemic. Whether such perceptions and behaviours towards ART in Guatemala may be different post Covid-19, is a study worthy of follow-up investigation. What is significant about the present findings is, the data collected before and during the outbreak of the Covid-19 pandemic. A unique opportunity that can only be replicated retrospectively i.e., what people can recall about their perceptions and behaviour about ART before the period of the Covid-19 outbreak? More specifically, there are significant implications from the four studies reported for practitioners and those involved in infertility treatments, in giving the best advice to their patients and to the Guatemalan public

The scalar sector in the Myers-Pospelov model

We construct a perturbative expansion of the scalar sector in the Myers-Pospelov model, up to second order in the Lorentz violating parameter and taking into account its higher-order time derivative character. This expansion allows us to construct an hermitian positive-definite Hamiltonian which provides a correct basis for quantization. Demanding that the modified normal frequencies remain real requires the introduction of an upper bound in the magnitude |k| of the momentum, which is a manifestation of the effective character of the model. The free scalar propagator, including the corresponding modified dispersion relations, is also calculated to the given order, thus providing the starting point to consider radiative corrections when interactions are introduced.Comment: Published in AIP Conf.Proc.977:214-223,200

Vector models with spontaneous Lorentz-symmetry breaking

Even though models with spontaneous Lorentz-symmetry breaking also damage gauge invariance, an interesting possibility that emerges is to interpret the resultant massless Goldstone bosons as the gauge bosons of the related gauge theory. In this contribution we review the conditions under which gauge invariance is recovered from such models. To illustrate our general approach we consider the classical Abelian bumblebee and Nambu models. In the former case we prove its connection with electrodynamics by a procedure which takes proper care of the gauge-fixing conditions. In the case of the Abelian Nambu model its relation with electrodynamics is established in such a way that the generalization to the non-Abelian case is straightforward.project CONACyT 237503 UNAM (Direccion General de Asuntos del Personal Academico) IN104815 CONACyT Posdoctoral Grant 234745info:eu-repo/semantics/publishedVersio

Mean properties and Free Energy of a few hard spheres confined in a spherical cavity

We use analytical calculations and event-driven molecular dynamics simulations to study a small number of hard sphere particles in a spherical cavity. The cavity is taken also as the thermal bath so that the system thermalizes by collisions with the wall. In that way, these systems of two, three and four particles, are considered in the canonical ensemble. We characterize various mean and thermal properties for a wide range of number densities. We study the density profiles, the components of the local pressure tensor, the interface tension, and the adsorption at the wall. This spans from the ideal gas limit at low densities to the high-packing limit in which there are significant regions of the cavity for which the particles have no access, due the conjunction of excluded volume and confinement. The contact density and the pressure on the wall are obtained by simulations and compared to exact analytical results. We also obtain the excess free energy for N=4, by using a simulated-assisted approach in which we combine simulation results with the knowledge of the exact partition function for two and three particles in a spherical cavity.Comment: 11 pages, 9 figures and two table