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1.
Cell ; 187(3): 750-763.e20, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38242132

RESUMEN

Breastfeeding offers demonstrable benefits to newborns and infants by providing nourishment and immune protection and by shaping the gut commensal microbiota. Although it has been appreciated for decades that breast milk contains complement components, the physiological relevance of complement in breast milk remains undefined. Here, we demonstrate that weanling mice fostered by complement-deficient dams rapidly succumb when exposed to murine pathogen Citrobacter rodentium (CR), whereas pups fostered on complement-containing milk from wild-type dams can tolerate CR challenge. The complement components in breast milk were shown to directly lyse specific members of gram-positive gut commensal microbiota via a C1-dependent, antibody-independent mechanism, resulting in the deposition of the membrane attack complex and subsequent bacterial lysis. By selectively eliminating members of the commensal gut community, complement components from breast milk shape neonate and infant gut microbial composition to be protective against environmental pathogens such as CR.


Asunto(s)
Proteínas del Sistema Complemento , Microbioma Gastrointestinal , Leche , Animales , Femenino , Humanos , Lactante , Ratones , Bacterias , Lactancia Materna , Citrobacter rodentium , Proteínas del Sistema Complemento/análisis , Factores Inmunológicos , Salud del Lactante , Leche Humana , Leche/química , Infecciones por Enterobacteriaceae/inmunología
2.
Cell ; 164(5): 859-71, 2016 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-26898329

RESUMEN

Identifying interventions that more effectively promote healthy growth of children with undernutrition is a pressing global health goal. Analysis of human milk oligosaccharides (HMOs) from 6-month-postpartum mothers in two Malawian birth cohorts revealed that sialylated HMOs are significantly less abundant in those with severely stunted infants. To explore this association, we colonized young germ-free mice with a consortium of bacterial strains cultured from the fecal microbiota of a 6-month-old stunted Malawian infant and fed recipient animals a prototypic Malawian diet with or without purified sialylated bovine milk oligosaccharides (S-BMO). S-BMO produced a microbiota-dependent augmentation of lean body mass gain, changed bone morphology, and altered liver, muscle, and brain metabolism in ways indicative of a greater ability to utilize nutrients for anabolism. These effects were also documented in gnotobiotic piglets using the same consortium and Malawian diet. These preclinical models indicate a causal, microbiota-dependent relationship between S-BMO and growth promotion.


Asunto(s)
Desarrollo Infantil , Desnutrición/dietoterapia , Leche Humana/química , Leche/química , Oligosacáridos/metabolismo , Animales , Bacteroides fragilis/genética , Bifidobacterium/clasificación , Bifidobacterium/genética , Química Encefálica , Modelos Animales de Enfermedad , Escherichia coli/genética , Heces/microbiología , Vida Libre de Gérmenes , Humanos , Lactante , Malaui , Masculino , Metabolómica , Ratones , Ratones Endogámicos C57BL , Microbiota
3.
CA Cancer J Clin ; 73(5): 461-479, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37329257

RESUMEN

There remains a need to synthesize linkages between social determinants of health (SDOH) and cancer screening to reduce persistent inequities contributing to the US cancer burden. The authors conducted a systematic review of US-based breast, cervical, colorectal, and lung cancer screening intervention studies to summarize how SDOH have been considered in interventions and relationships between SDOH and screening. Five databases were searched for peer-reviewed research articles published in English between 2010 and 2021. The Covidence software platform was used to screen articles and extract data using a standardized template. Data items included study and intervention characteristics, SDOH intervention components and measures, and screening outcomes. The findings were summarized using descriptive statistics and narratives. The review included 144 studies among diverse population groups. SDOH interventions increased screening rates overall by a median of 8.4 percentage points (interquartile interval, 1.8-18.8 percentage points). The objective of most interventions was to increase community demand (90.3%) and access (84.0%) to screening. SDOH interventions related to health care access and quality were most prevalent (227 unique intervention components). Other SDOH, including educational, social/community, environmental, and economic factors, were less common (90, 52, 21, and zero intervention components, respectively). Studies that included analyses of health policy, access to care, and lower costs yielded the largest proportions of favorable associations with screening outcomes. SDOH were predominantly measured at the individual level. This review describes how SDOH have been considered in the design and evaluation of cancer screening interventions and effect sizes for SDOH interventions. Findings may guide future intervention and implementation research aiming to reduce US screening inequities.


Asunto(s)
Neoplasias Pulmonares , Determinantes Sociales de la Salud , Humanos , Detección Precoz del Cáncer , Disparidades en el Estado de Salud , Escolaridad
4.
Nature ; 618(7963): 134-143, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37198477

RESUMEN

The African people and leaders1,2 have long seen education as a driving force of development and liberation, a view shared by international institutions3,4, as schooling has large economic and non-economic returns, particularly in low-income settings5. In this study, we examine the educational progress across faiths throughout postcolonial Africa, home to some of the world's largest Christian and Muslim communities. We construct comprehensive religion-specific measures of intergenerational mobility in education using census data from 2,286 districts in 21 countries and document the following. First, Christians have better mobility outcomes than Traditionalists and Muslims. Second, differences in intergenerational mobility between Christians and Muslims persist among those residing in the same district, in households with comparable economic and family backgrounds. Third, although Muslims benefit as much as Christians when they move early in life to high-mobility regions, they are less likely to do so. Their low internal mobility accentuates the educational deficit, as Muslims reside on average in areas that are less urbanized and more remote with limited infrastructure. Fourth, the Christian-Muslim gap is most prominent in areas with large Muslim communities, where the latter also register the lowest emigration rates. As African governments and international organizations invest heavily in educational programmes, our findings highlight the need to understand better the private and social returns to schooling across faiths in religiously segregated communities and to carefully think about religious inequalities in the take-up of educational policies6.


Asunto(s)
Escolaridad , Religión , Humanos , África , Cristianismo , Islamismo , Factores Socioeconómicos
5.
Physiol Rev ; 101(1): 303-318, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-32969772

RESUMEN

There are many unknowns for pregnant women during the coronavirus disease 2019 (COVID-19) pandemic. Clinical experience of pregnancies complicated with infection by other coronaviruses e.g., Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome, has led to pregnant woman being considered potentially vulnerable to severe SARS-CoV-2 infection. Physiological changes during pregnancy have a significant impact on the immune system, respiratory system, cardiovascular function, and coagulation. These may have positive or negative effects on COVID-19 disease progression. The impact of SARS-CoV-2 in pregnancy remains to be determined, and a concerted, global effort is required to determine the effects on implantation, fetal growth and development, labor, and neonatal health. Asymptomatic infection presents a further challenge regarding service provision, prevention, and management. Besides the direct impacts of the disease, a plethora of indirect consequences of the pandemic adversely affect maternal health, including reduced access to reproductive health services, increased mental health strain, and increased socioeconomic deprivation. In this review, we explore the current knowledge of COVID-19 in pregnancy and highlight areas for further research to minimize its impact for women and their children.


Asunto(s)
COVID-19/complicaciones , Complicaciones Infecciosas del Embarazo/patología , Complicaciones Infecciosas del Embarazo/virología , SARS-CoV-2 , Femenino , Humanos , Embarazo , Resultado del Embarazo , Factores de Riesgo
6.
Cell ; 148(3): 596-607, 2012 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-22304924

RESUMEN

Sex hormones such as estrogen and testosterone are essential for sexually dimorphic behaviors in vertebrates. However, the hormone-activated molecular mechanisms that control the development and function of the underlying neural circuits remain poorly defined. We have identified numerous sexually dimorphic gene expression patterns in the adult mouse hypothalamus and amygdala. We find that adult sex hormones regulate these expression patterns in a sex-specific, regionally restricted manner, suggesting that these genes regulate sex typical behaviors. Indeed, we find that mice with targeted disruptions of each of four of these genes (Brs3, Cckar, Irs4, Sytl4) exhibit extremely specific deficits in sex specific behaviors, with single genes controlling the pattern or extent of male sexual behavior, male aggression, maternal behavior, or female sexual behavior. Taken together, our findings demonstrate that various components of sexually dimorphic behaviors are governed by separable genetic programs.


Asunto(s)
Amígdala del Cerebelo/metabolismo , Perfilación de la Expresión Génica , Hipotálamo/metabolismo , Caracteres Sexuales , Conducta Sexual Animal , Agresión , Animales , Estro/metabolismo , Femenino , Masculino , Conducta Materna , Ratones , Ovario/metabolismo , Testículo/metabolismo , Testosterona/metabolismo
7.
Proc Natl Acad Sci U S A ; 121(41): e2412017121, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39352934

RESUMEN

Major initiatives attempt to prevent dementia by targeting modifiable risk factors. Low education is frequently pointed to, due to its relationship with dementia. Impact of education is difficult to assess, however, because of associations with multiple other factors, requiring large population-representative samples to tease the relationships apart. We studied 207,814 Norwegian men born between 1950 and 1959 who underwent compulsory cognitive testing during military conscription as young adults, to systematically test associations of education, cognition, and other important factors. Participants were grouped into five education levels and seven cognitive levels. A total of 1,521 were diagnosed with dementia between ages 60 and 69 y. While having compulsory education only was associated with increased risk (Hazard ratio [HR] = 1.37, CI: 1.17 to 1.60), this association was markedly attenuated when controlling for cognitive test scores (HR = 1.08, CI: 0.91 to 1.28). In contrast, low cognitive score was associated with double risk of later diagnosis, even when controlling for education (HR = 2.00, CI: 1.65 to 2.42). This relationship survived controlling for early-life socioeconomic status and replicated within pairs of brothers. This suggests that genetic and environmental factors shared within families, e.g., common genetics, parental education, socioeconomic status, or other shared experiences, cannot account for the association. Rather, independent, nonfamilial factors are more important. In contrast, within-family factors accounted for the relationship between low education and diagnosis risk. In conclusion, implementing measures to increase cognitive function in childhood and adolescence appears to be a more promising strategy for reducing dementia burden.


Asunto(s)
Cognición , Demencia , Escolaridad , Humanos , Demencia/epidemiología , Demencia/prevención & control , Masculino , Cognición/fisiología , Factores de Riesgo , Persona de Mediana Edad , Anciano , Noruega/epidemiología , Adolescente
8.
Blood ; 143(4): 311-319, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-37788408

RESUMEN

ABSTRACT: Occupational exposure to medical agents and ionizing radiation has been suggested as a possible risk factor for childhood cancer. However, the relationship between such exposure and pediatric malignant neoplasms has not yet been comprehensively studied. This cohort study aimed to investigate the association between parental occupational exposure to hazardous medical agents or ionizing radiation and the risk of childhood cancer in offspring. Data from a large birth cohort in Japan, which included 104 062 fetuses, were analyzed. The primary outcome was the development of leukemia or brain tumors diagnosed by community physicians during the first 3 years after birth. Exposure factors were medical agents, including anticancer agents, ionizing radiation, and anesthetics, handled by mothers during pregnancy or by fathers for 3 months before conception. The incidence of leukemia, but not of brain tumors, was higher in mothers exposed to anticancer drugs. Multivariable regression analysis showed that maternal exposure to anticancer drugs was associated with an increased risk of leukemia in offspring older than 1 year (adjusted relative risk, 7.99 [95% confidence interval, 1.98-32.3]). Detailed information obtained from medical certificates of patients with identified leukemia revealed no infant leukemia but acute lymphoblastic leukemias in the exposed group. Our findings suggest that maternal occupational exposure to anticancer drugs may be a potential risk factor for acute lymphoblastic leukemia in offspring older than 1 year. Effective prevention methods may be necessary to prevent maternal exposure to anticancer drugs and to reduce the risk of childhood malignant neoplasms.


Asunto(s)
Antineoplásicos , Neoplasias Encefálicas , Exposición Profesional , Leucemia-Linfoma Linfoblástico de Células Precursoras , Masculino , Embarazo , Femenino , Humanos , Niño , Exposición Materna/efectos adversos , Exposición Paterna/efectos adversos , Estudios de Cohortes , Japón/epidemiología , Factores de Riesgo , Madres , Exposición Profesional/efectos adversos , Antineoplásicos/efectos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Estudios de Casos y Controles
9.
Nature ; 587(7834): 426-431, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33029014

RESUMEN

Infant cries evoke powerful responses in parents1-4. Whether parental animals are intrinsically sensitive to neonatal vocalizations, or instead learn about vocal cues for parenting responses is unclear. In mice, pup-naive virgin females do not recognize the meaning of pup distress calls, but retrieve isolated pups to the nest after having been co-housed with a mother and litter5-9. Distress calls are variable, and require co-caring virgin mice to generalize across calls for reliable retrieval10,11. Here we show that the onset of maternal behaviour in mice results from interactions between intrinsic mechanisms and experience-dependent plasticity in the auditory cortex. In maternal females, calls with inter-syllable intervals (ISIs) from 75 to 375 milliseconds elicited pup retrieval, and cortical responses were generalized across these ISIs. By contrast, naive virgins were neuronally and behaviourally sensitized to the most common ('prototypical') ISIs. Inhibitory and excitatory neural responses were initially mismatched in the cortex of naive mice, with untuned inhibition and overly narrow excitation. During co-housing experiments, excitatory responses broadened to represent a wider range of ISIs, whereas inhibitory tuning sharpened to form a perceptual boundary. We presented synthetic calls during co-housing and observed that neurobehavioural responses adjusted to match these statistics, a process that required cortical activity and the hypothalamic oxytocin system. Neuroplastic mechanisms therefore build on an intrinsic sensitivity in the mouse auditory cortex, and enable rapid plasticity for reliable parenting behaviour.


Asunto(s)
Corteza Auditiva/fisiología , Conducta Materna/fisiología , Plasticidad Neuronal/fisiología , Estimulación Acústica , Animales , Corteza Auditiva/citología , Potenciales Postsinápticos Excitadores , Femenino , Vivienda para Animales , Conducta Materna/psicología , Ratones , Inhibición Neural/fisiología , Oxitocina/metabolismo , Sinapsis/metabolismo , Factores de Tiempo , Vocalización Animal
10.
Proc Natl Acad Sci U S A ; 120(25): e2210704120, 2023 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-37307478

RESUMEN

Group-based educational disparities are smaller in classrooms where teachers express a belief that students can improve their abilities. However, a scalable method for motivating teachers to adopt such growth mindset-supportive teaching practices has remained elusive. In part, this is because teachers often already face overwhelming demands on their time and attention and have reason to be skeptical of the professional development advice they receive from researchers and other experts. We designed an intervention that overcame these obstacles and successfully motivated high-school teachers to adopt specific practices that support students' growth mindsets. The intervention used the values-alignment approach. This approach motivates behavioral change by framing a desired behavior as aligned with a core value-one that is an important criterion for status and admiration in the relevant social reference group. First, using qualitative interviews and a nationally representative survey of teachers, we identified a relevant core value: inspiring students' enthusiastic engagement with learning. Next, we designed a ~45-min, self-administered, online intervention that persuaded teachers to view growth mindset-supportive practices as a way to foster such student engagement and thus live up to that value. We randomly assigned 155 teachers (5,393 students) to receive the intervention and 164 teachers (6,167 students) to receive a control module. The growth mindset-supportive teaching intervention successfully promoted teachers' adoption of the suggested practices, overcoming major barriers to changing teachers' classroom practices that other scalable approaches have failed to surmount. The intervention also substantially improved student achievement in socioeconomically disadvantaged classes, reducing inequality in educational outcomes.


Asunto(s)
Éxito Académico , Intervención basada en la Internet , Humanos , Escolaridad , Estudiantes , Aprendizaje
11.
Proc Natl Acad Sci U S A ; 120(8): e2209123120, 2023 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-36780521

RESUMEN

Academic achievement in the first year of college is critical for setting students on a pathway toward long-term academic and life success, yet little is known about the factors that shape early college academic achievement. Given the important role sleep plays in learning and memory, here we extend this work to evaluate whether nightly sleep duration predicts change in end-of-semester grade point average (GPA). First-year college students from three independent universities provided sleep actigraphy for a month early in their winter/spring academic term across five studies. Findings showed that greater early-term total nightly sleep duration predicted higher end-of-term GPA, an effect that persisted even after controlling for previous-term GPA and daytime sleep. Specifically, every additional hour of average nightly sleep duration early in the semester was associated with an 0.07 increase in end-of-term GPA. Sensitivity analyses using sleep thresholds also indicated that sleeping less than 6 h each night was a period where sleep shifted from helpful to harmful for end-of-term GPA, relative to previous-term GPA. Notably, predictive relationships with GPA were specific to total nightly sleep duration, and not other markers of sleep, such as the midpoint of a student's nightly sleep window or bedtime timing variability. These findings across five studies establish nightly sleep duration as an important factor in academic success and highlight the potential value of testing early academic term total sleep time interventions during the formative first year of college.


Asunto(s)
Duración del Sueño , Sueño , Humanos , Universidades , Estudiantes , Escolaridad
12.
Proc Natl Acad Sci U S A ; 120(31): e2308798120, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37487074

RESUMEN

Mammalian infants depend on parental care for survival, with numerous consequences for their behavioral development. We investigated the epigenetic and neurodevelopmental mechanisms mediating the impact of early biparental care on development of alloparenting behavior, or caring for offspring that are not one's own. We find that receiving high parental care early in life leads to slower epigenetic aging of both sexes and widespread male-specific differential expression of genes related to synaptic transmission and autism in the nucleus accumbens. Examination of parental care composition indicates that high-care fathers promote a male-specific increase in excitatory synapses and increases in pup retrieval behavior as juveniles. Interestingly, females raised by high-care fathers have the opposite behavioral response and display fewer pup retrievals. These results support the concept that neurodevelopmental trajectories are programmed by different features of early-life parental care and reveal that male neurodevelopmental processes are uniquely sensitive to care by fathers.


Asunto(s)
Conducta Animal , Padre , Humanos , Femenino , Animales , Masculino , Conducta Animal/fisiología , Conducta Materna/fisiología , Núcleo Accumbens , Padres , Conducta Paterna , Arvicolinae/fisiología
13.
Proc Natl Acad Sci U S A ; 120(1): e2216315120, 2023 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-36577065

RESUMEN

Behavioral science interventions have the potential to address longstanding policy problems, but their effects are typically heterogeneous across contexts (e.g., teachers, schools, and geographic regions). This contextual heterogeneity is poorly understood, however, which reduces the field's impact and its understanding of mechanisms. Here, we present an efficient way to interrogate heterogeneity and address these gaps in knowledge. This method a) presents scenarios that vividly represent different moderating contexts, b) measures a short-term behavioral outcome (e.g., an academic choice) that is known to relate to typical intervention outcomes (e.g., academic achievement), and c) assesses the causal effect of the moderating context on the link between the psychological variable typically targeted by interventions and this short-term outcome. We illustrated the utility of this approach across four experiments (total n = 3,235) that directly tested contextual moderators of the links between growth mindset, which is the belief that ability can be developed, and students' academic choices. The present results showed that teachers' growth mindset-supportive messages and the structural opportunities they provide moderated the link between students' mindsets and their choices (studies 1 to 3). This pattern was replicated in a nationally representative sample of adolescents and did not vary across demographic subgroups (study 2), nor was this pattern the result of several possible confounds (studies 3 to 4). Discussion centers on how this method of interrogating contextual heterogeneity can be applied to other behavioral science interventions and broaden their impact in other policy domains.


Asunto(s)
Éxito Académico , Estudiantes , Adolescente , Humanos , Estudiantes/psicología , Instituciones Académicas , Escolaridad
14.
Physiol Rev ; 98(3): 1241-1334, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29717932

RESUMEN

Hypoxia is one of the most common and severe challenges to the maintenance of homeostasis. Oxygen sensing is a property of all tissues, and the response to hypoxia is multidimensional involving complicated intracellular networks concerned with the transduction of hypoxia-induced responses. Of all the stresses to which the fetus and newborn infant are subjected, perhaps the most important and clinically relevant is that of hypoxia. Hypoxia during gestation impacts both the mother and fetal development through interactions with an individual's genetic traits acquired over multiple generations by natural selection and changes in gene expression patterns by altering the epigenetic code. Changes in the epigenome determine "genomic plasticity," i.e., the ability of genes to be differentially expressed according to environmental cues. The genomic plasticity defined by epigenomic mechanisms including DNA methylation, histone modifications, and noncoding RNAs during development is the mechanistic substrate for phenotypic programming that determines physiological response and risk for healthy or deleterious outcomes. This review explores the impact of gestational hypoxia on maternal health and fetal development, and epigenetic mechanisms of developmental plasticity with emphasis on the uteroplacental circulation, heart development, cerebral circulation, pulmonary development, and the hypothalamic-pituitary-adrenal axis and adipose tissue. The complex molecular and epigenetic interactions that may impact an individual's physiology and developmental programming of health and disease later in life are discussed.


Asunto(s)
Desarrollo Fetal , Hipoxia Fetal/metabolismo , Adaptación Fisiológica , Tejido Adiposo/embriología , Animales , Epigénesis Genética , Femenino , Corazón Fetal/crecimiento & desarrollo , Cardiopatías/etiología , Humanos , Hipertensión Pulmonar/congénito , Sistema Hipotálamo-Hipofisario , Salud Materna , Sistema Hipófiso-Suprarrenal , Circulación Placentaria , Embarazo
15.
Annu Rev Med ; 74: 199-216, 2023 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-36706746

RESUMEN

Maternal mortality is unusually high in the United States compared to other wealthy nations and is characterized by major disparities in race/ethnicity, geography, and socioeconomic factors. Similar to other developed nations, the United States has seen a shift in the underlying causes of pregnancy-related death, with a relative increase in mortality resulting from diseases of the cardiovascular system and preexisting medical conditions. Improved continuity of care aimed at identifying reproductive-age women with preexisting conditions that may heighten the risk of maternal death, preconception management of risk factors for major adverse pregnancy outcomes, and primary care visits within the first year after delivery may offer opportunities to address gaps in medical care contributing to the unacceptable rates of maternal mortality in the United States.


Asunto(s)
Etnicidad , Mortalidad Materna , Embarazo , Humanos , Femenino , Estados Unidos/epidemiología , Factores de Riesgo
16.
CA Cancer J Clin ; 68(5): 329-339, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30191964

RESUMEN

This article summarizes cancer mortality trends and disparities based on data from the National Center for Health Statistics. It is the first in a series of articles that will describe the American Cancer Society's vision for how cancer prevention, early detection, and treatment can be transformed to lower the cancer burden in the United States, and sets the stage for a national cancer control plan, or blueprint, for the American Cancer Society goals for reducing cancer mortality by the year 2035. Although steady progress in reducing cancer mortality has been made over the past few decades, it is clear that much more could, and should, be done to save lives through the comprehensive application of currently available evidence-based public health and clinical interventions to all segments of the population. CA Cancer J Clin 2018;000:000-000. © 2018 American Cancer Society.


Asunto(s)
Disparidades en el Estado de Salud , Neoplasias/prevención & control , Adolescente , Adulto , Anciano , Neoplasias de la Mama/mortalidad , Niño , Neoplasias Colorrectales/mortalidad , Detección Precoz del Cáncer , Escolaridad , Femenino , Disparidades en Atención de Salud , Humanos , Neoplasias Pulmonares/mortalidad , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Neoplasias/epidemiología , Neoplasias/mortalidad , Patient Protection and Affordable Care Act , Factores Raciales , Fumar/epidemiología , Estados Unidos/epidemiología
17.
Nature ; 574(7776): 99-102, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31578486

RESUMEN

Sexual imprinting-a phenomenon in which offspring learn parental traits and later use them as a model for their own mate preferences-can generate reproductive barriers between species1. When the target of imprinting is a mating trait that differs among young lineages, imprinted preferences may contribute to behavioural isolation and facilitate speciation1,2. However, in most models of speciation by sexual selection, divergent natural selection is also required; the latter acts to generate and maintain variation in the sexually selected trait or traits, and in the mating preferences that act upon them3. Here we demonstrate that imprinting, in addition to mediating female mate preferences, can shape biases in male-male aggression. These biases can act similarly to natural selection to maintain variation in traits and mate preferences, which facilitates reproductive isolation driven entirely by sexual selection. Using a cross-fostering study, we show that both male and female strawberry poison frogs (Oophaga pumilio) imprint on coloration, which is a mating trait that has diverged recently and rapidly in this species4. Cross-fostered females prefer to court mates of the same colour as their foster mother, and cross-fostered males are more aggressive towards rivals that share the colour of their foster mother. We also use a simple population-genetics model to demonstrate that when both male aggression biases and female mate preferences are formed through parental imprinting, sexual selection alone can (1) stabilize a sympatric polymorphism and (2) strengthen the trait-preference association that leads to behavioural reproductive isolation. Our study provides evidence of imprinting in an amphibian and suggests that this rarely considered combination of rival and sexual imprinting can reduce gene flow between individuals that bear divergent mating traits, which sets the stage for speciation by sexual selection.


Asunto(s)
Anuros/genética , Anuros/fisiología , Especiación Genética , Impresión Genómica , Preferencia en el Apareamiento Animal/fisiología , Pigmentación de la Piel/genética , Agresión , Animales , Anuros/anatomía & histología , Costa Rica , Femenino , Flujo Génico/genética , Masculino , Herencia Materna/genética , Nicaragua , Panamá , Herencia Paterna/genética , Polimorfismo Genético
19.
Nature ; 568(7752): 391-394, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30918405

RESUMEN

Access to adequate housing is a fundamental human right, essential to human security, nutrition and health, and a core objective of the United Nations Sustainable Development Goals1,2. Globally, the housing need is most acute in Africa, where the population will more than double by 2050. However, existing data on housing quality across Africa are limited primarily to urban areas and are mostly recorded at the national level. Here we quantify changes in housing in sub-Saharan Africa from 2000 to 2015 by combining national survey data within a geostatistical framework. We show a marked transformation of housing in urban and rural sub-Saharan Africa between 2000 and 2015, with the prevalence of improved housing (with improved water and sanitation, sufficient living area and durable construction) doubling from 11% (95% confidence interval, 10-12%) to 23% (21-25%). However, 53 (50-57) million urban Africans (47% (44-50%) of the urban population analysed) were living in unimproved housing in 2015. We provide high-resolution, standardized estimates of housing conditions across sub-Saharan Africa. Our maps provide a baseline for measuring change and a mechanism to guide interventions during the era of the Sustainable Development Goals.


Asunto(s)
Mapeo Geográfico , Vivienda/estadística & datos numéricos , África del Sur del Sahara , Escolaridad , Composición Familiar , Vivienda/economía , Vivienda/provisión & distribución , Factores Socioeconómicos , Desarrollo Sostenible/economía
20.
Ann Intern Med ; 177(1): 50-64, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38163377

RESUMEN

BACKGROUND: Severe maternal morbidity and mortality are worse in the United States than in all similar countries, with the greatest effect on Black women. Emerging research suggests that disrespectful care during childbirth contributes to this problem. PURPOSE: To conduct a systematic review on definitions and valid measurements of respectful maternity care (RMC), its effectiveness for improving maternal and infant health outcomes for those who are pregnant and postpartum, and strategies for implementation. DATA SOURCES: Systematic searches of Ovid Medline, CINAHL, Embase, Cochrane Central Register of Controlled Trials, PsycInfo, and SocINDEX for English-language studies (inception to July 2023). STUDY SELECTION: Randomized controlled trials and nonrandomized studies of interventions of RMC versus usual care for effectiveness studies; additional qualitative and noncomparative validation studies for definitions and measurement studies. DATA EXTRACTION: Dual data abstraction and quality assessment using established methods, with resolution of disagreements through consensus. DATA SYNTHESIS: Thirty-seven studies were included across all questions, of which 1 provided insufficient evidence on the effectiveness of RMC to improve maternal outcomes and none studied RMC to improve infant outcomes. To define RMC, authors identified 12 RMC frameworks, from which 2 main concepts were identified: disrespect and abuse and rights-based frameworks. Disrespect and abuse components focused on recognizing birth mistreatment; rights-based frameworks incorporated aspects of reproductive justice, human rights, and antiracism. Five overlapping framework themes include freedom from abuse, consent, privacy, dignity, communication, safety, and justice. Twelve tools to measure RMC were validated in 24 studies on content validity, construct validity, and internal consistency, but lack of a gold standard limited evaluation of criterion validity. Three tools specific for RMC had at least 1 study demonstrating consistency internally and with an intended construct relevant to U.S. settings, but no single tool stands out as the best measure of RMC. LIMITATIONS: No studies evaluated other health outcomes or RMC implementation strategies. The lack of definition and gold standard limit evaluation of RMC tools. CONCLUSION: Frameworks for RMC are well described but vary in their definitions. Tools to measure RMC demonstrate consistency but lack a gold standard, requiring further evaluation before implementation in U.S. settings. Evidence is lacking on the effectiveness of implementing RMC to improve any maternal or infant health outcome. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality. (PROSPERO: CRD42023394769).


Asunto(s)
Servicios de Salud Materna , Obstetricia , Lactante , Embarazo , Femenino , Humanos , Respeto , Parto Obstétrico , Periodo Posparto , Calidad de la Atención de Salud
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