Social participation of older people in urban and rural areas: Canadian Longitudinal Study on Aging.

BACKGROUND AND OBJECTIVES: Although the positive influence of social activity on health is now well-established, a complex relationship exists among social participation, personal, social and the environment. Social participation of older adults was examined in rural and urban settings to identify features of the built-environment and perception of neighborhood specific to the locale. RESEARCH DESIGN AND METHODS: Using cross-sectional data from the Canadian Longitudinal Study on Aging (CLSA), we examined social participation and health of older people (65 + yrs) in relation to the built environment and sociocultural contexts for urban and rural areas. A social participation index was derived from responses on the frequency of participating in 8 social activities over the past 12 months. Personal, household and neighborhood indicators were examined to develop multivariable regression models for social participation in urban and rural cohorts. RESULTS: No meaningful differences were seen with the frequency of social participation between rural and urban settings; however, the type of community-related activities differed in that a greater proportion of urban participants reported sports and educational/cultural events than rural participants. Service club activities were greater for rural than urban participants. Different neighborhood features were statistically significant factors in explaining social participation in rural than in urban locales, although transportation was a significant factor regardless of locale. Trustworthiness, belonging and safety were perceived factors of the neighborhood associated with higher social participation for rural participants. DISCUSSION AND IMPLICATIONS: The relationship between home and health becomes stronger as one ages. Social and physical features of built environment specific to urban and rural settings need to be considered when implementing appropriate social activities for older people.

A molecular view of plasticization of polyvinyl alcohol.

Although macromolecules such as polymers are in widespread industrial use, pure formulations rarely have precisely the properties new applications demand. Pure polymer is often too brittle and inflexible, necessitating plasticizers to soften or toughen films and bulk polymer materials. In practice, new formulations are developed by extensive trial-and-error methods, as no general molecular explanations exist for the mechanism of plasticization to aid in determining the optimal structure and concentration of plasticizers. Here, through atomistic molecular simulations augmented with advanced sampling techniques, we develop an atomic-level picture of the processes in plasticization by directly calculating free energies that govern the interaction between polymers and small-molecule plasticizers. This work focuses on the influence of two common plasticizer molecules-glycerol and sorbitol-interacting with polyvinyl alcohol (PVA), a frequently used component of polymer films. In particular, we focus on conformational and hydrogen bond structure changes induced in globules of PVA by the plasticizer molecules, with the hypothesis that hydrogen bonding plays a role in the incorporation of these plasticizers into PVA and, thus, in the observed mechanical properties. While we focus on nanoscopic systems, we observe distinct preferences in the conformational free energy that can be connected to the performance of polymer materials at laboratory and industrial scales. This work presents a new molecular perspective from which effective plasticizers can be developed and presents a firm basis from which important analyses of plasticization in complex chemical environments relevant to industry may be developed.

Simple kinetics, assay, and trends for soil microbial catalases.

In this report, we expand upon the enzymology and ecology of soil catalases through development and application of a simple kinetic model and field-amenable assay based upon volume displacement. Through this approach, we (A) directly relate apparent Michaelis-Menten terms to the catalase reaction mechanism, (B) obtain upper estimates of the intrinsic rate constants for the catalase community (k3'), along with moles of catalase per 16S rRNA gene copy number, (C) utilize catalase specific activities (SAs) to obtain biomass estimates of soil and permafrost communities (LOD, ~104 copy number gdw-1), and (D) relate kinetic trends to changes in bacterial community structure. In addition, this novel kinetic approach simultaneously incorporates barometric adjustments to afford comparisons across field measurements. As per our model, and when compared to garden soils, biological soil crusts exhibited ~2-fold lower values for k3', ≥105-fold higher catalase moles per biomass (250-1200 zmol copy number-1), and ~104-fold higher SAs per biomass (74-230 fkat copy number-1); whereas the highest SAs were obtained from permafrost and high-elevation soil communities (5900-6700 fkat copy number-1). In sum, the total trends suggest that microbial communities which experience higher degrees of native oxidative stress possess higher basal intracellular catalase concentrations and SAs per biomass.

Arrested dynamics of the dipolar hard sphere model.

We report the combined results of molecular dynamics simulations and theoretical calculations concerning various dynamical arrest transitions in a model system representing a dipolar fluid, namely, N (soft core) rigid spheres interacting through a truncated dipole-dipole potential. By exploring different regimes of concentration and temperature, we find three distinct scenarios for the slowing down of the dynamics of the translational and orientational degrees of freedom: at low (η = 0.2) and intermediate (η = 0.4) volume fractions, both dynamics are strongly coupled and become simultaneously arrested upon cooling. At high concentrations (η≥ 0.6), the translational dynamics shows the features of an ordinary glass transition, either by compressing or cooling down the system, but with the orientations remaining ergodic, thus indicating the existence of partially arrested states. In this density regime, but at lower temperatures, the relaxation of the orientational dynamics also freezes. The physical scenario provided by the simulations is discussed and compared against results obtained with the self-consistent generalized Langevin equation theory, and both provide a consistent description of the dynamical arrest transitions in the system. Our results are summarized in an arrested states diagram which qualitatively organizes the simulation data and provides a generic picture of the glass transitions of a dipolar fluid.

Spherical harmonic projections of the static structure factor of the dipolar hard sphere model: Theory vs simulations.

We investigate the static correlations of a dipolar fluid in terms of the irreducible coefficients of the spherical harmonic expansion of the static structure factor. To this end, we develop a theoretical framework based on a soft-core version of Wertheim's solution of the mean spherical approximation (MSA), which renders the analytical determination of such coefficients possible. The accuracy of this approximation is tested by a comparison against the results obtained with the assistance of extensive molecular dynamics simulations at different regimes of concentration and temperature. Crucial aspects for the comparison of the results provided by the two methods are carefully discussed, concerning the different reference frames used in theory and simulations to describe rotations and orientations, and leading to important differences in the behavior of correlation functions with the same combination of spherical harmonic indices. We find a remarkable agreement between the two approaches in the fluid regime, thus providing a first stringent comparison of the irreducible coefficients of the spherical harmonic expansion of the dipolar fluid's static structure factor, provided by the MSA theory and molecular dynamics simulations.

Self-Selection of Bathroom-Assistive Technology: Development of an Electronic Decision Support System (Hygiene 2.0).

BACKGROUND: A clinical algorithm (Algo) in paper form is used in Quebec, Canada, to allow health care workers other than occupational therapists (OTs) to make bathroom adaptation recommendations for older adults. An integrated knowledge transfer process around Algo suggested an electronic version of this decision support system (electronic decision support system [e-DSS]) to be used by older adults and their caregivers in search of information and solutions for their autonomy and safety in the bathroom. OBJECTIVE: This study aims to (1) create an e-DSS for the self-selection of bathroom-assistive technology by community-dwelling older adults and their caregivers and (2) assess usability with lay users and experts to improve the design accordingly. METHODS: On the basis of a user-centered design approach, the process started with content identification for the prototype through 7 semistructured interviews with key informants of various backgrounds (health care providers, assistive technology providers, and community services) and 4 focus groups (2 with older adults and 2 with caregivers). A thematic content transcript analysis was carried out and used during the creation of the prototype. The prototype was refined iteratively using think-aloud and observation methods with a clinical expert (n=1), researchers (n=3), OTs (n=3), older adults (n=3), and caregivers (n=3), who provided information on the usability of the e-DSS. RESULTS: Overall, 4 themes served as the criteria for the prototype of the electronic Algo (Hygiene 2.0 [H2.0]): focus (safety, confidentiality, well-being, and autonomy), engage, facilitate (simplify, clarify, and illustrate), and access. For example, users first pay attention to the images (engage and illustrate) that can be used to depict safe postures (safety), illustrate questions embedded in the decision support tool (clarify and illustrate), and demonstrate the context of the use of assistive technology (safety and clarify). CONCLUSIONS: The user-centered design of H2.0 allowed the cocreation of an e-DSS in the form of a website, in line with the needs of community-dwelling older adults and their caregivers seeking bathroom-assistive technology that enables personal hygiene. Each iteration improved usability and brought more insight into the users' realities, tailoring the e-DSS to the implementation context.

A Finite-Difference Solution for the EEG Forward Problem in Inhomogeneous Anisotropic Media.

Accurate source localization of electroencephalographic (EEG) signals requires detailed information about the geometry and physical properties of head tissues. Indeed, these strongly influence the propagation of neural activity from the brain to the sensors. Finite difference methods (FDMs) are head modelling approaches relying on volumetric data information, which can be directly obtained using magnetic resonance (MR) imaging. The specific goal of this study is to develop a computationally efficient FDM solution that can flexibly integrate voxel-wise conductivity and anisotropy information. Given the high computational complexity of FDMs, we pay particular attention to attain a very low numerical error, as evaluated using exact analytical solutions for spherical volume conductor models. We then demonstrate the computational efficiency of our FDM numerical solver, by comparing it with alternative solutions. Finally, we apply the developed head modelling tool to high-resolution MR images from a real experimental subject, to demonstrate the potential added value of incorporating detailed voxel-wise conductivity and anisotropy information. Our results clearly show that the developed FDM can contribute to a more precise head modelling, and therefore to a more reliable use of EEG as a brain imaging tool.

Genetic Overview of the Maya Populations: Mitochondrial DNA Haplogroups.

We identified mitochondrial DNA haplogroups A, B, C, and D in 75 present-day Maya individuals, 24 Maya individuals of the colonial period, and 1 pre-Columbian Maya individual from Quintana Roo, Mexico. We examined these data together with those of 21 Maya populations reported in the literature, comprising 647 present-day Maya individuals and 71 ancient Maya individuals. A demographic study based on analysis of fertility and endogamy was carried out in two modern Maya populations to identify cultural factors that influence the mitochondrial haplogroup genetic diversity. Most present-day and ancient Maya populations show a distribution pattern of mitochondrial haplogroup frequencies A, C, B, and D in decreasing order, with haplogroup D absent in several populations. Considering only modern Maya populations with at least 50 individuals analyzed, the present-day Tzotzil and Lacandon populations from Chiapas show the highest and lowest genetic diversity, 0.706 and 0.025, respectively. Our results show small genetic differences between the Maya populations, with the exception of the present-day Tojolabal and Lacandon populations from Chiapas. The present-day Lacandon population from Chiapas differs from other Maya populations in showing almost only haplogroup A. This result suggests a long history of isolation and endogamy as well as a possible founder effect inside the Lacandonian rain forest. The contemporary Tojolabal population is the only one with an unusual mitochondrial haplogroup pattern, exhibiting a frequency of haplogroup B higher than A and the absence of haplogroup C. With a small sample size, the pre-Columbian Copán Maya show a high content of haplogroup C and a low frequency of haplogroup D. The genetic homogeneity of the Maya populations is indicative of a common origin and nearly continuous gene flow in the long term within a general isolation of the whole group, in contrast to the Nahua populations that had different origins. Our demographic study showed high fertility rates and high levels of endogamy in the present-day Maya populations from Quintana Roo that are consistent with their general low genetic diversity. We propose that the genetic similarity among ancient and present-day Maya populations persists due to a strong sense of social cohesion and identity that impacts their marriage practices, keeping this cultural group isolated. These factors have constrained gene flow inside the Maya region and have impeded the differentiation among the Maya. Discernment of genetic differentiation within the peninsula is constrained by the lack of sampling documentation in the literature.

Hypocholesterolemia is an independent risk factor for depression disorder and suicide attempt in Northern Mexican population.

BACKGROUND: Cholesterol has been associated as a risk factor for cardiovascular disease. Recently, however, there is growing evidence about crucial requirement of neuron membrane cholesterol in the organization and function of the 5-HT1A serotonin receptor. For this, low cholesterol level has been reported to be associated with depression and suicidality. However there have been inconsistent reports about this finding and the exact relationship between these factors remains controversial. Therefore, we investigated the link between serum cholesterol and its fractions with depression disorder and suicide attempt in 467 adult subjects in Mexican mestizo population. METHODS: Plasma levels of total cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL-c) and low density lipoprotein cholesterol (LDL-c) were determined in 261 MDD patients meeting the DSM-5 criteria for major depressive disorder (MDD), 59 of whom had undergone an episode of suicide attempt, and 206 healthy controls. RESULTS: A significant decrease in total cholesterol, LDL-cholesterol, VLDL-cholesterol and triglyceride serum levels was observed in the groups of MDD patients and suicide attempt compared to those without suicidal behavior (p < 0.05). After adjusting for covariates, lower cholesterol levels were significantly associated with MDD (OR 4.229 CI 95% 2.555 - 7.000, p<.001) and suicide attempt (OR 5.540 CI 95% 2.825 - 10.866, p<.001) CONCLUSIONS: These results support the hypothesis that lower levels of cholesterol are associated with mood disorders like MDD and suicidal behavior. More mechanistic studies are needed to further explain this association.

Mitochondrial DNA Analysis of Mazahua and Otomi Indigenous Populations from Estado de México Suggests a Distant Common Ancestry.

The indigenous Mazahua and Otomi have inhabited the same localities in Estado de México since pre-Columbian times. Their languages, Mazahua and Otomi, belong to the Oto-Manguean linguistic family, and although they share cultural traditions and a regional history that suggest close genetic relationships and common ancestry, the historical records concerning their origin are confusing. To understand the biological relationships between Mazahua and Otomi, we analyzed mitochondrial DNA (mtDNA) genetic variation. We identified the mtDNA haplogroups by restriction fragment length polymorphism typing and sequenced hypervariable region 1 of the mtDNA control region in 141 Mazahua and 100 Otomi. These results showed that Otomi exhibit a higher frequency of haplogroup A than B, whereas Mazahua exhibit the opposite pattern. In the Otomi EM population the most frequent subhaplogroups are, in order of frequency, A2, B2, and C1, whereas in the Mazahua 1 population they are B2, D1, and A2. The most frequent haplotypes (Ht) of haplogroups A and B are Ht2 (A) and Ht58 (B2g1) in Mazahua 1 and Ht8 (A2), Ht22 (A2ao1), and Ht53 (B2c2b) in Otomi EM. The genetic differences between the Mazahua 1 and Otomi EM suggest a distant shared ancestry and a moderate degree of maternal admixture that has not obscured the difference of their mtDNA patterns. These unexpected results suggest the Mazahua and Otomi probably descend from the same group but separated very early and admixed with other Mesoamerican populations before their arrival in Central Mexico. The historical evidence of conflicting relations between the Mazahua and Otomi and the almost nonexistence of marriage between them could be responsible for maintaining only a moderate degree of maternal admixture.

Making rural and remote communities more age-friendly: experts' perspectives on issues, challenges, and priorities.

With the growing interest worldwide in making communities more age-friendly, it is becoming increasingly important to understand the factors that help or hinder communities in attaining this goal. In this article, we focus on rural and remote communities and present perspectives of 42 experts in the areas of aging, rural and remote issues, and policy who participated in a consensus conference on age-friendly rural and remote communities. Discussions highlighted that strengths in rural and remote communities, such as easy access to local leaders and existing partnerships, can help to further age-friendly goals; however, addressing major challenges, such as lack of infrastructure and limited availability of social and health services, requires regional or national government buy-in and funding opportunities. Age-friendly work in rural and remote communities is, therefore, ideally embedded in larger age-friendly initiatives and supported by regional or national policies, programs, and funding sources.

[Atypical preeclampsia and perinatal success: a case report]. / Preeclampsia atípica y éxito perinatal: reporte de caso.

Preeclampsia is a multi systemic syndrome of variable severity, pregnancy specific, consequence of an abnormal vascular response to placentation, with increase in peripheral vascular resistance, stimulation of platelet aggregation, activation of the coagulation cascade, and endothelial dysfunction. In the majority of cases, it will present with gestational hypertension and proteinuria, after 20 weeks, nevertheless, in other cases, it has presented as an atypical form (with absence of hypertension and/or proteinuria) behaving like severe preeclampsia. We report the case of a patient, 32 year old primigravida, with a 26.6 weeks gestation, that comes to the office with postprandial projectile vomiting. At the time of admission, she presents with sudden headache, phosphenes, and tinnitus, associated to epigastric pain, with a blood pressure of 110/70 mmHg; fetal heart rate of 146 bpm, normal lower limbs and reflexes. The Complete Blood Count and liver function tests are within normal values, urinalysis with proteinuria. Normal hepatic ultrasound. Obstetric ultrasound; with fetal measurements of 2.6 weeks below, with flattening of the growth curve, Doppler flowmetry with an increase in placental resistance and oligohydramnios. Given the clinical manifestations compatible with severe preeclampsia, magnesium sulfate, and antenatal corticosteroid therapy are initiated, and abdominal termination of pregnancy is decided. A female newborn is obtained, of 595 g, Apgar 4/7. On immediate puerperium, she presents with an increase in blood pressure of 150/90 mmHg, discharged with normal blood pressure 96 hours later. The newborn girl was discharged when she reached a weight of 2000 g. Today, she is neurologically unimpaired.

Development of the Standardized Navigation Of Winter Mobility & Accessibility Network (SNOWMAN) course.

Introduction: Manual wheelchairs (MWC) users have limited mobility during winter months as they encounter many environmental barriers that restrict their community participation. This paper outlines the creation and standardization of an outdoor environment designed to simulate the real-life conditions and obstacles experienced by MWC users in winter. Methods and results: This study consisted of four phases. In Phase 1, researchers used a qualitative ethnographic approach to document the specific challenges and adaptive strategies used by MWC users in winter conditions. In Phase 2, key informants with expertise in MWC winter mobility were invited to co-design the Standardized Navigation Of Winter Mobility & Accessibility Network (SNOWMAN) course. Participants reviewed draft design solutions and offered their input and suggestions to expand upon the initial design. A second co-design workshop included additional key informants, including service providers, policymakers, and professionals with expertise in landscape architecture and engineering, to validate the design solution. The workshops resulted in a detailed illustration of the SNOWMAN course, including five sections: platforms with side slopes, a miniature ice rink, curbs and curb cuts, a path with uneven winter surfaces, and modular ramps at various slopes. Phases 3 and 4 marked the conclusion of the study and involved fabrication of the SNOWMAN course and establishment of a standardized protocol for course setup and maintenance. Discussion: The project aimed to offer several additional potential benefits, supported by the various stakeholders across the study phases, that extend beyond creation of a controlled and safe environment for wheelchair users to develop their winter mobility skills. Practicing wheelchair skills in this area may assist wheelchair users in gaining confidence which may ultimately translate to increased participation in the community.

Exploring the home environment of adults living with autism spectrum disorder: a qualitative study.

Introduction: The challenges experienced by adults living with autism spectrum disorder (ASD) regarding their interaction with their home environment are thinly documented, although these issues persist with age. Based on the Model of Competence, this study aims to explore the human and nonhuman elements of the home environment influencing the functioning of autistic adults. Methods: An exploratory-descriptive qualitative study was conducted in Quebec City, Canada, with autistic adults (n = 6). Individual semi-structured interviews were undertaken by a single interviewer until data saturation was reached. A content analysis was conducted using NVivo software with a list of codes adjusted according to new emerging themes. Results: Eight themes emerged and were grouped into three categories: 1) Person - Adult living with ASD: coping skills, anxiety; 2) Microsystem - Home environment: entourage, sensory elements, spatial arrangement; 3) Person-environment interaction: routines, socialization, control. The experiences of autistic adults highlight the varied interactions experienced with the nonhuman and human elements of their homes, sometimes resulting in a situation of handicap related to their activities and roles. Conclusion: This qualitative exploration of the environmental challenges experienced at home by autistic adults introduces a better understanding of the person-environment interaction, allowing for easier functional assessment and improved home support.

Current learning strategies in fire evacuation for seniors and people with disabilities in private seniors' residences and long-term care homes: a scoping review.

Current strategies for teaching evacuation methods in private seniors' residences (PSR) and long-term care (LTCH) homes may pose risks to people with disabilities (PWD) and seniors' physical and psychological health. This study aimed to address the following questions: (1) Which are the current fire evacuation learning strategies used with PWD or seniors? (2) What are the barriers and facilitators for PWD and seniors' during fire evacuation and learning strategies in PSR and LTCH? (3) What is the existing equipment that could be used with PWD seniors?. A scoping review of grey and scientific literature was done in six databases and Google scholar. Additional information was found on Québec government websites. This review identified 13 scientific papers and 22 documents. Twenty barriers (personal = 9, environmental = 11), and 14 facilitators (personal = 4, environmental = 10) were extracted. The current fire evacuation learning strategies currently used can be grouped into three categories: drills; training; promotion of a fire safety plan. Six types of evacuation equipment were found; however, their use has been scarcely documented. Safety for seniors during fire evacuation is still an important issue to be improved. Increasing awareness and creating new practices and tools that consider the strengths and difficulties of seniors seems to be a promising avenue for improving evacuation.

Large-scale analysis of neural activity and connectivity from high-density electroencephalographic data.

INTRODUCTION: High-density electroencephalography (hdEEG) is a technique used for the characterization of the neural activity and connectivity in the human brain. The analysis of EEG data involves several steps, including signal pre-processing, head modelling, source localization and activity/connectivity quantification. Visual check of the analysis steps is often necessary, making the process time- and resource-consuming and, therefore, not feasible for large datasets. FINDINGS: Here we present the Noninvasive Electrophysiology Toolbox (NET), an open-source software for large-scale analysis of hdEEG data, running on the cross-platform MATLAB environment. NET combines all the tools required for a complete hdEEG analysis workflow, from raw signals to final measured values. By relying on reconstructed neural signals in the brain, NET can perform traditional analyses of time-locked neural responses, as well as more advanced functional connectivity and brain mapping analyses. The extracted quantitative neural data can be exported to provide broad compatibility with other software. CONCLUSIONS: NET is freely available (https://github.com/bind-group-kul/net) under the GNU public license for non-commercial use and open-source development, together with a graphical user interface (GUI) and a user tutorial. While NET can be used interactively with the GUI, it is primarily aimed at unsupervised automation to process large hdEEG datasets efficiently. Its implementation creates indeed a highly customizable program suitable for analysis automation and tight integration into existing workflows.

Experiencing accessibility of historical heritage places with individuals living with visible and invisible disabilities.

Introduction: Around 16% of world's population lives with visible and invisible disabilities. People with disabilities' participation may be limited because of the environmental obstacles. Moreover, historic heritage places were built before the development of accessibility standards and the rights of people living with disabilities and the majority were not designed to be accessible. Access to historic heritage places is important for carrying out the activities in place but also to create and reinforce identity. The aim of this study was to explore the experiences of people with visible and invisible disabilities when visiting heritage sites considering accessibility issues. Methods: This study is a qualitative interpretive description. Participants were adults with visible (e.g., motor disability) or invisible (e.g., autism) disabilities. For data collection, go along interviews (also referred to in the literature as "walking interview" in two different locations in the Historic District of Old Quebec in Quebec City were conducted. Thematic analysis was done. Results: Twenty-one participants completed two go along interviews: one in the Séminaire de Québec (Seminary of Quebec City) and the other in Petit-Champlain and Place Royale areas of Quebec City. Three themes emerged: (1) Obstacles and impact on participation; (2) Disabling accessibility; and (3) Heritage meaning. Discussion: The barriers identified by participants are diverse and differ according to the person and the type of disability. However, social and leisure activities were particularly limited, despite the strategies developed by some participants. Participants in the study demonstrated an interest in accessing to heritage places, therefore it seems essential to consider the needs of people with disabilities when developing accessibility solutions, and to seek a balance between preserving heritage and promoting inclusive and equitable access for all.

Evaluation of three pedestrian phasing with audible pedestrian signals configurations in Quebec City (Canada): an exploratory study of blind or visually impaired persons' sense of safety, preferences, and expectations.

PURPOSE: This exploratory study aimed to evaluate the preferences, expectations, and sense of safety of blind or visually impaired persons regarding three types of pedestrian phasing with audible pedestrian signals configurations that exist in Quebec City (Canada). These include: 1) exclusive phasing with non-directional audible pedestrian signals; 2) exclusive phasing with directional audible pedestrian signals; and 3) concurrent phasing with directional audible pedestrian signals. METHODS: Thirty-two blind or visually impaired persons were asked to complete a survey. Their preferences and expectations regarding audible pedestrian signals were documented through a series of simulations. Their sense of safety regarding the three existing configurations were also documented. Subsequently, semi-directed, individual interviews with 11 of the individuals who had completed the survey were conducted to build off the collected information. RESULTS: No formal consensus regarding many of the issues discussed were established as participants' responses varied too significantly. However, findings suggest that the exclusive phasing with directional audible pedestrian signals configuration is perceived to be the safest option by the participants. CONCLUSION: This study may have practical implications on the design of intersections (e.g., selection of a type of pedestrian phasing with audible pedestrian signal) and the training of blind or visually impaired pedestrians.IMPLICATIONS FOR REHABILITATIONThe addition of audible pedestrian signals to pedestrian signals heightens the sense of safety of blind or visually impaired persons.This study may have practical implications on the design of intersections with audible pedestrian signals and the selection of a type of audible pedestrian signals based on intersection characteristics.Since many participants reported a lower sense of safety when faced with concurrent phasing, it is recommended that more intensive orientation and mobility interventions be provided to blind or visually impaired pedestrians who use this type of traffic signals.Educating road users about blind or visually impaired pedestrians appears also essential.

[Placental acretism, a repercussion of modern obstetrics]. / Acretismo placentario, una de las repercusiones de la obstetricia moderna.

The evolution of obstetrics has led us to beneficial discoveries, and to new pathologies. The increase of cesarean section is due to elective cesarean section and cesarean section on maternal request, which have increased in popularity over the last past few years. Without condemning them, we have to take into account the benefits, as well as the complications that may arise from them, leading us to pathologies that were not frequent before, such as placental acretism, which today, is the second cause of obstetric hemorrhage worldwide. For us to be able to counteract the potential complications, it is important to have a multidisciplinary team that allows us to decrease maternal and neonatal death, starting with primary prevention, capable of identifying risk factors, so as to be able to make an early diagnosis. Today, imaging studies have described suggestive markers of acretism at early gestational age, such as 8.4 to 14.2 weeks, allowing us a wide range of time for decision making. In the majority of cases, it is required to perform an obstetrical hysterectomy as a definitive treatment, which is a real challenge for medical skills. Nevertheless, conservative treatment with limited evidence, with uterotonics, and uterine artery embolization, has proved useful. When set on a scale, the risks and benefits of an elective, or maternal request cesarean section, we can understand why we have concluded that, in absence of maternal or fetal indications, natural delivery is the best way to resolve pregnancy.