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Seasonal dimorphism in the body shape of marine invertebrates has been poorly explored compared to vertebrates. We aim to investigate through traditional (body length/width ratio, dorsal elevation ratio and angle of elevation) and geometric (centroid size and shape geometric configurations) morphometrics the effect of gonad maturity (via the gonadosomatic index [GSI] and gonad development stages [GDS]) on changes in body shape in males and females of two latitudinally different populations of the broadcast-spawning intertidal mollusc Chiton articulatus. We confirmed that C. articulatus does not present external sexual dimorphism since sex does not have a significant effect on body shape (1 %); instead, dimorphism was seasonal and related to the reproductive season, and varied across populations, probably because in the subtropical zone additional energy is invested in shell (scleritome) bending at the same time as the gonad matures, which is opposite of what occurs in the tropical zone. C. articulatus shows a narrower body shape (i.e., diminished body width) during its gonad maturity compared to the rest of the GDS and is corroborated by a body length/width ratio that contributes the greatest variation in the geometric shape descriptors (18 %), just below the centroid size (24 %). The expression of centroid size differences shows a correspondence with the change in body dimensions expressed by the three morphometric ratios during gonad maturity. The use of traditional body ratios over time may be useful in polyplacophoran molluscs as a proxy tool to estimate gonad maturity and to provide a reliable indication of the reproductive season., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Background: An estimated 43% of children under age 5 in low- and middle-income countries (LMICs) experience compromised development due to poverty, poor nutrition, and inadequate psychosocial stimulation. Numerous early childhood development (ECD) parenting interventions have been shown to be effective at improving ECD outcomes, at least in the short-term, but they are (a) still too expensive to implement at scale in low-resource and rural settings, and (b) their early impacts tend to fade over time. New approaches to deliver effective ECD parenting interventions that are low-cost, scalable, and sustainable are sorely needed., Methods: Our study will experimentally test a traditional in-person group-based delivery model for an evidence-based ECD parenting intervention against a hybrid-delivery model that increasingly substitutes in-person meetings with remote (mHealth) delivery via smartphones, featuring audiovisual content and WhatsApp social interactions and learning. We will assess the relative effectiveness and cost of this hybrid-delivery model compared to in-person delivery and will extend the interventions over two years to increase their ability to sustain changes in parenting behaviors and ECD outcomes longer-term. Our evaluation design is a cluster Randomized Controlled Trial (cRCT) across 90 villages and approximately 1200 households. Midline and endline surveys collected 12 and 24 months after the start of the interventions, respectively, will examine short- and sustained two-year intention-to-treat impacts on primary outcomes. We will also examine the mediating pathways using mediation analysis. We hypothesize that a hybrid-delivery ECD intervention will be lower in cost, but remote interactions among participants may be an inferior substitute for in-person visits, leaving open the question of the most cost-effective program., Discussion: Our goal is to determine the best model to maximize the intervention's reach and sustained impacts to improve child outcomes. By integrating delivery into the ongoing operations of local Community Health Promoters (CHPs) within Kenya's rural health care system, and utilizing new low-cost technology, our project has the potential to make important contributions towards discovering potentially scalable, sustainable solutions for resource-limited settings., Trial Registration: NCT06140017 (02/08/2024) AEARCTR0012704., (© 2024. The Author(s).)

Background: An estimated 43% of children under age 5 in low- and middle-income countries (LMICs) experience compromised development due to poverty, poor nutrition, and inadequate psychosocial stimulation. Numerous early childhood development (ECD) parenting interventions have been shown to be effective at improving ECD outcomes, at least in the short-term, but they are a) still too expensive to implement at scale in low-resource and rural settings, and b) their early impacts tend to fade over time. New approaches to deliver effective ECD parenting interventions that are low-cost, scalable, and sustainable are sorely needed., Methods: Our study will experimentally test a traditional in-person group-based delivery model for an evidence-based ECD parenting intervention against a hybrid-delivery model that increasingly substitutes in-person meetings for a remote (mHealth) delivery via smartphones, featuring audiovisual content and WhatsApp social interactions and learning. We will assess the relative effectiveness and cost of this hybrid-delivery model against purely in-person delivery and will extend the interventions over two years to increase their ability to sustain changes in parenting behaviors and ECD outcomes longer-term. Our evaluation design is a cluster Randomized Controlled Trial (cRCT) across 90 villages and approximately 1200 households. Midline and endline surveys collected 12 and 24 months after the start of the interventions, respectively, will examine short- and sustained two-year intention-to-treat impacts on primary outcomes. We will also examine the mediating pathways using Mediation Analysis. We hypothesize that a hybrid-delivery ECD intervention will be lower cost, but remote interactions among participants may be an inferior substitute for in-person visits, leaving open the question of the most cost-effective program., Discussion: Our goal is to determine the best model to maximize the intervention's reach and sustained impacts to improve child outcomes. By integrating delivery into the ongoing operations of local Community Health Promoters (CHPs) within Kenya's rural health care system, and utilizing new low-cost technology, our project has the potential to make important contributions towards discovering potentially scalable, sustainable solutions for resource-limited settings., Trial Registration: NCT06140017 (02/08/2024) AEARCTR0012704., Competing Interests: Competing interests The authors declare that they have no competing interests.

We present a three-dimensional (3D) imaging technique for the fast tracking of microscopic objects in a fluid environment. Our technique couples digital holographic microscopy with three-dimensional localization via parabolic masking. Compared with existing approaches, our method reconstructs 3D volumes from single-plane images, which greatly simplifies image acquisition, reduces the demand on microscope hardware, and facilitates tracking higher densities of microscopic particles while maintaining similar levels of precision. We demonstrate utility of this method in magnetic tweezer experiments, opening their use to multiplexed single-molecule force spectroscopy assays, which were previously limited by particle crowding and fast dissociation times. We propose that our technique will also be useful in other applications that involve the tracking of microscopic objects in three dimensions, such as studies of microorganism motility and 3D flow characterization of microfluidic devices., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 Biophysical Society. Published by Elsevier Inc. All rights reserved.)

Evidence on the role of father involvement in children's development from low-resource settings is very limited and historically has only relied on maternal reports of father's direct engagement activities such as reading to the child. However, fathers can also potentially influence their children's development via greater positive involvement with the mother, such as by offering interpersonal support or sharing decision-making duties. Such positive intrahousehold interactions can benefit maternal mental health and wellbeing, and ultimately children's development. We use data collected from mothers, fathers and children in the context of the cluster randomized controlled trial evaluation of Msingi Bora, a responsive parenting intervention implemented across 60 villages in rural western Kenya, to explore the various pathways through which fathers may influence their children's outcomes. In an endline survey in Fall 2019 among a sample of 681 two-parent households with children aged 16-34 months, fathers reported on measures of their behaviors towards children and with mothers, mothers reported on their wellbeing and behaviors, and interviewers assessed child cognitive and language development with the Bayley Scales. In adjusted multivariate regression analyses we found that greater father interpersonal support to mothers and greater participation in shared household decision-making were positively associated with children's development. These associations were partially mediated through maternal wellbeing and behaviors. We found no association between fathers' direct engagement in stimulation activities with children and children's outcomes. Inviting fathers to the program had no impact on their involvement or on any maternal or child outcomes, and fathers attended sessions at low rates. Overall, our results show the potential promises and challenges of involving fathers in a parenting intervention in a rural low-resource setting. Our findings do highlight the importance of considering intrahousehold pathways of influence in the design of parenting interventions involving fathers., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The Cuban vaccine, first in the world with proven efficacy against group B-caused disease, is based on outer membrane proteins from B meningococci capable of inducing long-lasting and high-titered bactericidal antibodies in humans. This bactericidal activity has a wide spectrum against all pathogenic group B Neisseria meningitidis tested. A randomized, double-blind controlled trial of the vaccine efficacy was performed during 1987-1989 with 106,000 10-14 years old students from 197 boarding schools in seven provinces. The efficacy obtained was 83% (chi 2, p less than 0.002; Fischer exact, p less than 0.001). In a second field trial including 133,600 persons from 5 months to 24 years of age in Ciego de Avila province (30 cases/10(5) inhabitants, the highest incidence rate in Cuba) by comparing vaccinated and non-vaccinated population after 2.5 years of observation and careful follow-up, the efficacy and safety was confirmed. Because of these results and because of the very low reactogenicity of the vaccine, the Ministry of Public Health took the advice of the Scientific Council to vaccinate all children between 3 months and 6 years of age in the most affected provinces. No severe or long lasting reactions to the vaccine were observed after the millions of doses administered. The efficacy of vaccination varied in the provinces between 83% and 94%, among age groups ranging from 3 months and 20 years. After 3 years of massive application no severe reactions occurred and one of the most severe epidemics has been practically eradicated.

Sensitive spectrophotometric and spectrofluorimetric procedures for the determination of palladium have been developed, based on solvent-extraction of the ion-pair formed between Rhodamine B and the anionic complex of Pd(II) with thiocyanate. With an organic to aqueous phase-volume ratio of 1:5, the molar absorptivity is 9.0 x 10(4) l.mole(-1).cm(-1) and the absorbance of the reagent blank is 0.026. Spectrophotometrically, palladium can be determined in the range 0.1-8.8 mug. Spectrofluorimetrically, it can be determined over the range 0.04-1.5 mug. The spectrophotometric procedure has been applied to the determination of palladium in dental alloys, organopalladium compounds and hydrogenation catalysts.

A sensitive and rapid spectrophotometric method for the determination of cadmium is described, based on the formation of a blue complex at pH 4 between the anionic iodide complex of cadmium(II) and Malachite Green; the colour is stabilized with poly(vinyl alcohol). The calibration graph for measurement at 685 nm is linear over the range 1-50 mug of cadmium per 25 ml of final solution, with a relative standard deviation of +/-1.7% for 1 mug/ml cadmium. The molar absorptivity is 6.1 x 10(4) 1.mole(-1).cm(-1). The method can be successfully adapted for FIA, the peak height being proportional to the cadmium concentration over the range 0.1-3 mug/ml; a two-channel manifold is used and an improvement in selectivity is obtained. The use of a gradient tube is demonstrated to give a good calibration for Cd(II) over the range 2 x 10(-2) -2 x 10(-6)M.

In a slightly acidic medium (sodium acetate-acetic acid buffer, pH 4) saccharin and Nile Blue form an ion-association compound which is extractable into methyl isobutyl ketone and allows the spectrophotometric determination of saccharin. At 630 nm Beer's law is obeyed over the saccharin concentration range 0.1-3.5 microg/ml in the aqueous phase and the apparent molar absorptivity is 5.8 x 10(4) l.mole(-1).cm(-1). The method shows good selectivity and can be applied to the determination of saccharin in artificial sweeteners, soft drinks and toothpastes.