RESUMEN
We propose a numerical approach to study mesoscopic fluctuations in quantum dots with chiral symmetry. Our method involves applying the random-hopping model to a tight-binding Hamiltonian, allowing us to calculate the conductance and shot-noise power distributions for systems belonging to the three chiral symmetry classes of random matrix theory. Furthermore, we demonstrate that the spectral fluctuations of quantum dots belonging to the Wigner-Dyson symmetry classes of random matrix theory can be obtained by applying the random-hopping model to a scattering region that was originally integrable, thus bypassing the need to use the boundaries of chaotic billiards.
RESUMEN
Aiming of self-sustainable production, the search for biodegradable and biocompatible materials has brought with it the need to know the physicochemical and dielectric characteristics of polysaccharide-based composite structures, which can be used as important and promising raw materials for biotechnology and electronic industries. Galactomannans are polysaccharides, extracted from seeds and microbiological sources, consisting of mannose and galactose. In this context, this work aimed to extract, purify and characterize by XRD, FTIR and impedance spectroscopy galactomannan obtained from seeds of Adenanthera pavonina L. The purification process was made with ethyl alcohol at concentrations of 70, 80 and 90 %. Polymeric films were prepared by solvent slow evaporation at low temperatures. XRD measurements revealed that Galactomannan from Adenanthera pavonina L., after purification, has a semi-crystalline structure due to the identification of two peaks the first between 5.849° and 6.118° and the second between 20.011° and 20.247°. FTIR spectra showed the functional groups associated with monosaccharides of the galactomannan from Adenanthera pavonina L. seeds, as well as the typical polysaccharide bands and peaks, confirmed by literature data. The impedance results give an increment on the state-of-the-art of this biomaterial by showing the existence of dielectric relaxations, independent of the degree of purification, using the dielectric modulus formalism. The permittivity analysis reveals the presence of water in the structure of the film, whose dipoles contribute to the relatively high value of the dielectric constant. From the results obtained, it can be concluded that purified galactomannan has the potential for possible applications in the electronics industry as a green and eco-friendly dielectric material.
Asunto(s)
Fabaceae , Mananos , Mananos/análisis , Mananos/química , Fabaceae/química , Polisacáridos/química , Galactosa , Semillas/química , Materiales BiocompatiblesRESUMEN
Construction and demolition waste (CDW) is an environmental problem that affects all regions of the world. Particularly in the Brazilian Amazon Forest region, the volume of CDW generated almost doubled between 2007 and 2019. Indeed, despite Brazil having environmental regulations for waste management, these have been insufficient to solve the environmental problem because there is no CDW reverse supply chain (RSC) properly developed in the Amazon region. Previous studies have proposed a conceptual model of a CDW RSC but have hitherto failed to apply them against real world practice. This paper, therefore, attempts to test existing conceptual models that describe a CDW RSC against real industry practice prior to developing an applied model of a CDW RSC for the Brazilian Amazon. To modify the conceptual model for CDW RSC, qualitative data through 15 semi-structured interviews with five different types of stakeholders of the Amazonian CDW RSC were collected and analyzed using qualitative content analysis methods using NVivo software. The proposed applied model includes present and future reverse logistics (RL) practices, and strategies and tasks necessary for the implementation of a CDW RSC in the city of Belém of Pará, in the Brazilian Amazon. Findings reveal that several overlooked problems, particularly the limitations of the existing legal framework in Brazil, are not enough to promote a robust CDW RSC. This is perhaps the first study to examine CDW RSC in the Amazonian rainforest. Arguments provided in this study highlight the necessity for an Amazonian CDW RSC that must be promoted and regulated by the government. This can be addressed by the utilizing public-private partnership (PPP) for developing a CDW RSC.
RESUMEN
OBJECTIVES: We aimed to characterize neurocognitive impairment (NI) in an HIV-2 population using an observational cross-sectional study in four Portuguese hospitals. METHODS: Adult HIV-2-infected patients were included. Montreal Cognitive Assessment Test (MoCA) and International HIV Dementia Scale (IHDS) scales were applied for screening of NI. Patient Health Questionnaire-9 (PHQ-9) and Instrumental Activities of Daily Living (IADL) scales were used for assessment of depression and functionality. A multivariate analysis was performed to assess for risk factors for NI. RESULTS: Eighty-one patients were included, 50.6% of African origin (n = 41) and 49.4% of Portuguese origin (n = 40). The MoCA scale showed alterations in 81.5% of patients (100% of migrants vs. 62.5% of non-migrants, P < 0.001) and the IHDS scale showed alterations in 42%. Both scales were altered simultaneously in 35.8%. Variables independently associated with NI were age [odds ratio (OR) = 0.885] and migrant status (OR = 9.150). CONCLUSIONS: Neurocognitive impairment (both scales altered) was present in 35.8%, which is comparable to what is described for HIV-1. The MoCA performed worse in the migrant population and might not be applicable in this setting.
Asunto(s)
Complejo SIDA Demencia , Disfunción Cognitiva , Infecciones por VIH , Actividades Cotidianas , Adulto , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/etiología , Estudios Transversales , Infecciones por VIH/complicaciones , Infecciones por VIH/psicología , VIH-2 , Humanos , Pruebas de Estado Mental y Demencia , Pruebas NeuropsicológicasRESUMEN
The ground breaking extension of the key concept of phase structure to nonequilibrium regimes was only recently achieved in Floquet systems, characterized by a time-dependent quantum Hamiltonian with a periodic driving source. However, despite the theoretical advances, only very few systems are known to display experimental Floquet phases, not one of them employing a laser emission-based mechanism. Here we report the first experimental observation of a Floquet phase in a photonic system, a disordered fiber laser with spatial eigenmode localization. We apply a periodically oscillating cw pumping source that drives the random couplings of the Floquet Hamiltonian. A photonic Floquet spin-glass phase is demonstrated in the random-lasing regime by extensive measurements of the Parisi overlap parameter and asymmetry properties of its distribution. In contrast, in the fluorescent regime below threshold, the absence of mode localization prevents the stabilization of a Floquet phase. Our results are nicely described by theoretical arguments.
RESUMEN
OBJECTIVES: We aimed to explore associations between positive and negative symptoms, mindfulness, positive affect, and social safeness; and to understand the mediator role of positive emotions in the relationship between mindfulness and social safeness. METHOD: Fifty-six participants with a psychotic disorder were assessed with measures of mindfulness, negative and positive symptoms, positive affect, and social safeness. RESULTS: All variables were associated with each other except for positive symptoms and active affect. Mindfulness predicted social safeness through safe affect, when controlling for positive and negative symptoms. CONCLUSIONS: This study contributes to knowledge of mechanisms behind social safeness adding the role of mindfulness and activation of positive emotions. The continuing study of mindfulness as an important mechanism for social safeness will allow further improvement of interventions for psychosis.
Asunto(s)
Afecto/fisiología , Atención Plena , Trastornos Psicóticos/fisiopatología , Medio Social , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Percepción Social , Adulto JovenRESUMEN
Milk-fat globule epidermal growth factor (EGF) 8 protein (MFGE8), also known as lactadherin, promotes cell adhesion in an Arg-Gly-Asp (RGD)-dependent modus via integrins. In the present study, the expression of MFGE8 was examined in equine endometrium during oestrus and at Days 12 and 16 after ovulation in pregnant and non-pregnant mares and in mares during the 5th month of gestation. Results demonstrated that MFGE8 is expressed at the embryo- and fetal-maternal interface in equine pregnancy. In non-pregnant endometrium its expression was upregulated by oestrogen, a finding that was confirmed using endometrial explant culture. MFGE8 was expressed at similar levels by conceptuses collected 13 and 14 days after ovulation and by allantochorion sampled during the 5th month of gestation. Pericytes of endometrial blood vessels displayed strong MFGE8 expression upon in situ hybridisation. During the 5th month of gestation, the fetal side of the allantochorionic villi in particular displayed pronounced staining upon in situ hybridisation, confirming that MFGE8 expression is not restricted to early pregnancy but persists and is present at the fetal-maternal interface. Potential roles of MFGE8 in equine pregnancy include mediating cell-cell adhesion, promotion of angiogenesis and placental transfer of fatty acids.
Asunto(s)
Antígenos de Superficie/metabolismo , Endometrio/metabolismo , Proteínas de la Leche/metabolismo , Placenta/metabolismo , Animales , Endometrio/efectos de los fármacos , Estradiol/farmacología , Femenino , Caballos , Placenta/efectos de los fármacos , EmbarazoRESUMEN
The aim of this study was to evaluate the effects of high-impact physical exercise as a prophylactic and therapeutic means in osteopenic bones of rats submitted to ovariectomy and protein diet intake. A total of 64 Wistar rats were divided into eight groups (n = 8 each), being: OVX, ovx, standard diet and sedentary; OVXE, ovx, standard diet and jump; OVXP, ovx, high-protein diet and sedentary; and OVXEP, ovx, high-protein diet and jump; SH, sham, standard diet and sedentary; SHE, sham, standard diet and jump; SHP, sham, high-protein diet and sedentary; and SHEP, sham, high-protein diet and jump. OVX surgery consists of ovariectomy, and sham was the control surgery. The jumping protocol consisted of 20 jumps/day, 5 days/week. The bone structure was evaluated by densitometry, mechanical tests, histomorphometric, and immunohistochemical analyses. A high-protein diet resulted in increased bone mineral density (P = .049), but decreased maximal load (P = .026) and bone volume fraction (P = .023). The benefits of physical exercise were demonstrated by higher values of the maximal load in the trained groups compared to the sedentary groups (P < .001). The sham groups had decreased immunostaining of osteocalcin (P = .004) and osteopontin (P = .010) compared to ovx groups. However, the high-protein diet (P = .005) and jump exercise (P = .017) resulted in lower immunostaining of osteopontin compared to the standard diet and sedentary groups, respectively. In this experimental model, it was concluded that ovariectomy and a high-fat diet can negatively affect bone tissue and the high-impact exercise was not enough to suppress the deleterious effects caused by the protein diet and ovariectomy.
Asunto(s)
Densidad Ósea , Huesos/fisiología , Dieta Rica en Proteínas , Condicionamiento Físico Animal , Animales , Femenino , Osteocalcina/metabolismo , Osteopontina/metabolismo , Ovariectomía , Ratas , Ratas WistarRESUMEN
BACKGROUND: Child development is negatively impacted by HIV with children that are infected and affected by HIV performing worse than their peers in cognitive assessments. METHODS: We conducted a descriptive follow-up comparison study (n=989) in South Africa and Malawi. We tracked child development in 135 HIV-positive children compared to 854 uninfected children aged 4-13 years attending community-based organizations at baseline and again 12-15 months later. RESULTS: Children with HIV were more often stunted (58.8% vs. 27.4%) and underweight (18.7% vs. 7.1%). They also had significantly poorer general physical functioning (M=93.37 vs. M=97.00). HIV-positive children scored significantly lower on digit span and the draw-a-person task. CONCLUSIONS: These data clearly show that HIV infection poses a serious risk for child development and that there is a need for scaled up interventions. Community-based services may be ideally placed to accommodate such provision and deliver urgently needed support to these children.
Asunto(s)
Servicios de Salud del Niño , Disfunción Cognitiva/complicaciones , Disfunción Cognitiva/fisiopatología , Discapacidades del Desarrollo/complicaciones , Trastornos del Crecimiento/complicaciones , Trastornos del Crecimiento/fisiopatología , Infecciones por VIH/complicaciones , Fármacos Anti-VIH/uso terapéutico , Niño , Desarrollo Infantil , Servicios de Salud del Niño/organización & administración , Preescolar , Disfunción Cognitiva/rehabilitación , Disfunción Cognitiva/virología , Discapacidades del Desarrollo/epidemiología , Discapacidades del Desarrollo/fisiopatología , Discapacidades del Desarrollo/rehabilitación , Femenino , Estudios de Seguimiento , Trastornos del Crecimiento/virología , Infecciones por VIH/epidemiología , Infecciones por VIH/fisiopatología , Infecciones por VIH/rehabilitación , Necesidades y Demandas de Servicios de Salud , Humanos , Malaui/epidemiología , Masculino , Calidad de Vida , Factores Socioeconómicos , Sudáfrica/epidemiología , Delgadez/epidemiología , Delgadez/fisiopatología , Delgadez/virologíaRESUMEN
OBJECTIVE: To assess the effectiveness of laser surgery in fetuses with a cystic lung lesion with systemic arterial blood supply (hybrid lung lesion) at risk of perinatal death. METHODS: A cohort of five consecutive fetuses with a large hybrid lung lesion associated with hydrops and/or pleural effusion with severe lung compression was selected for percutaneous ultrasound-guided fetal laser ablation of the feeding artery (FLAFA) before 32 weeks' gestation in a single tertiary national referral center in Queretaro, Mexico. The primary outcomes were survival and need for postnatal surgery. RESULTS: FLAFA was performed successfully in all cases at a median gestational age of 24.9 (range, 24.4-31.7) weeks. After fetal intervention, dimensions in both lungs increased and fluid effusions resolved in all cases. All cases were delivered liveborn at term at a median gestational age of 39.6 (range, 38.0-39.7) weeks, without respiratory morbidity or need for oxygen support, resulting in perinatal survival of 100%. During follow-up, three (60%) cases showed progressive regression of the entire lung mass and did not require postnatal surgery, whereas in two (40%) cases a progressive decrease in size of the mass was observed but a cystic portion of the lung mass persisted and postnatal lobectomy was required. CONCLUSION: In fetuses with large hybrid lung lesions at risk of perinatal death, FLAFA is feasible and could improve survival and decrease the need for postnatal surgery. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Asunto(s)
Malformación Adenomatoide Quística Congénita del Pulmón/cirugía , Enfermedades Fetales/cirugía , Enfermedades Pulmonares/diagnóstico , Arterias/cirugía , Estudios de Cohortes , Malformación Adenomatoide Quística Congénita del Pulmón/complicaciones , Malformación Adenomatoide Quística Congénita del Pulmón/diagnóstico por imagen , Malformación Adenomatoide Quística Congénita del Pulmón/fisiopatología , Femenino , Enfermedades Fetales/diagnóstico por imagen , Enfermedades Fetales/fisiopatología , Terapias Fetales , Edad Gestacional , Humanos , Terapia por Láser , Enfermedades Pulmonares/complicaciones , Enfermedades Pulmonares/congénito , Enfermedades Pulmonares/diagnóstico por imagen , Enfermedades Pulmonares/fisiopatología , Enfermedades Pulmonares/cirugía , México , Embarazo , Estudios Prospectivos , Resultado del Tratamiento , Ultrasonografía Intervencional , Ultrasonografía PrenatalRESUMEN
AIMS: To evaluate the antibiofilm potential of water-soluble Moringa oleifera seed lectin (WSMoL) on Serratia marcescens and Bacillus sp. METHODS AND RESULTS: WSMoL inhibited biofilm formation by S. marcescens at concentrations lower than 2·6 µg ml-1 and impaired bacterial growth at higher concentrations, avoiding biofilm formation. For Bacillus sp., the lectin inhibited bacterial growth at all concentrations. The antibiofilm action of WSMoL is associated with damage to bacterial cells. WSMoL did not disrupt preformed S. marcescens biofilms but was able to damage cells inside them. On the other hand, the lectin reduced the number of cells in Bacillus sp. biofilm treated with it. WSMoL was able to control biofilm formation when immobilized on glass surface (116 µg cm-2 ), damaging S. marcescens cells and avoiding adherence of Bacillus sp. cells on glass. The Bacillus sp. isolate is member of Bacillus subtilis species complex and closely related to species of the conspecific 'amyloliquefaciens' group. CONCLUSION: WSMoL prevented biofilm development by S. marcescens and Bacillus sp. and the antibiofilm effect is also observed when the lectin is immobilized on glass. SIGNIFICANCE AND IMPACT OF THE STUDY: Taking together, our results provide support to the potential use of WSMoL for controlling biofilm formation by bacteria.
Asunto(s)
Antibacterianos/farmacología , Bacillus/efectos de los fármacos , Biopelículas/efectos de los fármacos , Lectinas/farmacología , Moringa oleifera/química , Extractos Vegetales/farmacología , Serratia marcescens/efectos de los fármacos , Antibacterianos/aislamiento & purificación , Bacillus/fisiología , Lectinas/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Semillas/química , Serratia marcescens/fisiologíaRESUMEN
Nutrition and physical training have important roles in the accumulation and maintenance of bone mass. The aim of this study was to evaluate, in ovariectomized rats (OVX), the effects of treadmill training (T) with high-fat diet (F) on weight gain and bone tissue properties with eight groups (n = 10) for 12 weeks: OVX SC (OVX, sedentary lifestyle, diet control); OVX SF; OVX TC; OVX TF; SH SC (SHAM, sedentary lifestyle, diet control); SH SF; SH TC; and SH TF. Weekly weight gain and final body composition were assessed. After euthanasia, tibiae were analyzed. The trained animals had higher body weight (P = 0.001), bone mineral density (P < 0.001), and trabecular bone (P < 0.001). The animals with a high-fat diet showed higher global fat (P < 0.001), percentage of global fat (P < 0.001) and deformation at impact (P = 0.031) and reduced tibial bone mineral content (P = 0.036). Physical training improves bone microarchitecture, without presenting an increase in impact resistance, and a high-fat diet increases body fat and impairs bone mineralization.
Asunto(s)
Composición Corporal , Densidad Ósea , Hueso Esponjoso/patología , Hueso Cortical/patología , Dieta Alta en Grasa , Condicionamiento Físico Animal , Tibia/patología , Aumento de Peso , Tejido Adiposo , Animales , Femenino , Ovariectomía , Ratas , Ratas WistarRESUMEN
9-cis-epoxycarotenoid dioxygenase (NCED) encodes a key enzyme in abscisic acid (ABA) biosynthesis. Little is known regarding the regulation of stress response by NCEDs at physiological levels. In the present study, we generated transgenic tobacco overexpressing an NCED3 ortholog from citrus (CsNCED3) and investigated its relevance in the regulation of drought stress tolerance. Wild-type (WT) and transgenic plants were grown under greenhouse conditions and subjected to drought stress for 10 days. Leaf predawn water potential (Ψwleaf), stomatal conductance (gs), net photosynthetic rate (A), transpiration rate (E), instantaneous (A/E) and intrinsic (A/gs) water use efficiency (WUE), and in situ hydrogen peroxide (H2O2) and abscisic acid (ABA) production were determined in leaves of irrigated and drought-stressed plants. The Ψwleaf decreased throughout the drought stress period in both WT and transgenic plants, but was restored after re-watering. No significant differences were observed in gs between WT and transgenic plants under normal conditions. However, the transgenic plants showed a decreased (P ≤ 0.01) gs on the 4th day of drought stress, which remained lower (P ≤ 0.001) than the WT until the end of the drought stress. The A and E levels in the transgenic plants were similar to those in WT; therefore, they exhibited increased A/gs under drought conditions. No significant differences in A, E, and gs values were observed between the WT and transgenic plants after re-watering. The transgenic plants had lower H2O2 and higher ABA than the WT under drought conditions. Our results support the involvement of CsNCED3 in drought avoidance.
Asunto(s)
Dioxigenasas/biosíntesis , Nicotiana/fisiología , Proteínas de Plantas/biosíntesis , Ácido Abscísico/biosíntesis , Adaptación Fisiológica , Citrus/enzimología , Citrus/genética , Dioxigenasas/genética , Dioxigenasas/metabolismo , Sequías , Hojas de la Planta/enzimología , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Estrés Fisiológico , Nicotiana/enzimología , Nicotiana/genética , Nicotiana/metabolismoRESUMEN
Many of the risk factors for violence against children are particularly prevalent in families and communities affected by HIV/AIDS. Yet, in sub-Saharan Africa, where HIV rates are high, efforts to prevent or address violence against children and its long-lasting effects are hampered by a lack of evidence. We assessed the relationship between violence exposure and mental health among HIV-affected children attending community-based organisations in South Africa (n = 834) and Malawi (n = 155, total sample n = 989) at baseline and 12-15-month follow-up. Exposure to violence in the home and in the community was high. HIV-negative children who lived with an HIV-positive person experienced most violence overall, followed by HIV-positive children. Children unaffected by HIV experienced least violence (all p < .05). Interpersonal violence in the home predicted child depression (ß = 0.17, p < .001), trauma symptoms (ß = 0.17, p < .001), lower self-esteem (ß = -0.17, p < .001), and internalising and externalising behavioural problems (ß = 0.07, p < .05), while exposure to community violence predicted trauma symptoms (ß = 0.16, p < .001) and behavioural problems (ß = 0.07, p < .05). Harsh physical discipline predicted lower self-esteem (ß = -0.18, p < .001) and behavioural problems for children (ß = 0.24, p < .001). Exposure to home (OR: 1.89, 95% CI: 1.23-2.85) and community violence predicted risk behaviour (OR: 2.39, 95% CI: 1.57-3.62). Over time, there was a decrease in depressed mood and problem behaviours, and an increase in self-esteem for children experiencing different types of violence at baseline. This may have been due to ongoing participation in the community-based programme. These data highlight the burden of violence in these communities and possibilities for programmes to include violence prevention to improve psychosocial well-being in HIV-affected children.
Asunto(s)
Exposición a la Violencia/psicología , Infecciones por VIH/psicología , Violencia , Niño , Preescolar , Investigación Participativa Basada en la Comunidad , Estudios Transversales , Depresión/epidemiología , Trastorno Depresivo/epidemiología , Exposición a la Violencia/estadística & datos numéricos , Femenino , Humanos , Modelos Logísticos , Estudios Longitudinales , Malaui/epidemiología , Masculino , Salud Mental , Factores de Riesgo , Asunción de Riesgos , Sudáfrica/epidemiologíaRESUMEN
Gender is an important factor in child development. Especially in sub-Saharan Africa, girls have often been shown to be less likely to access education compared to boys. The consequence of this has been that that programmes addressing child development are often aimed at girls in order to redress gender imbalances. This study examines the effect of gender on the development of children attending community-based organisations in high HIV-affected areas, and explores whether community-based organisation attendance was associated with any changes in gender differences over time. Baseline data from 989 children and 12-15 month follow from 854 (86% response rate) were used to examine gender differences in children from Malawi and South Africa. At baseline, where there were differences by gender, these tended to disadvantage boys. It was found that boys were significantly more often found to be subjected to violence. Boys showed worse performance at school and more behavioural problems than girls. These gender differences persisted from baseline to follow-up. At follow-up, boys self-reported significantly worse average quality of life than girls. Only harsh discipline differed by gender in progression over time: boys experienced a stronger reduction in harsh physical discipline than girls from baseline to follow-up. Since harsh discipline was associated with boys' worse educational outcomes and behavioural problems, our data cautiously suggests that gender differences could be reduced over time. In conclusion, our data suggests that, perhaps due to the narrow equity approach focusing on provision for girls, boys may be overlooked. As a result, there are some specific experiences where boys are generally worse off. These differences have distinct ramifications for the educational and emotional development of boys. A broader equity approach to child development might be warranted to ensure that the needs of both girls and boys are considered, and that boys are not overlooked.
Asunto(s)
Identidad de Género , Infecciones por VIH/psicología , Calidad de Vida , Niño , Investigación Participativa Basada en la Comunidad , Femenino , Humanos , Estudios Longitudinales , Malaui/epidemiología , Masculino , Instituciones Académicas , Sudáfrica/epidemiología , Violencia/prevención & controlRESUMEN
OBJECTIVE: Many studies that document child outcomes in the context of parental HIV - which has been established as a risk factor for child development - focus on older children/adolescents. Studies also concentrate on the status of the primary caregiver, not other household members who might be infected. DESIGN: This study examined the effects of caregiver and household HIV on child development (4-13 years) in South Africa and Malawi (2011-2014). METHODS: Data were gathered from 989 children and their primary caregivers at baseline and repeated at 12-15 months follow-up (86.5% follow-up rate). Only caregivers of a single child and caregiver/child dyads without missing data were included, providing a sample of 808 dyads for analysis. Children were divided into three groups according to caregiver-reported HIV burden: having an HIV-positive primary caregiver (19.8%), having HIV in the household (14.2%) or no HIV (66%). RESULTS: The HIV burden was positively associated with an array of negative child outcomes, often mediated by caregiver depression levels. Family HIV burden at baseline affected child behavioural problems at follow-up indirectly through carer depression (B = 0.02; CI = 0.003, 0.06). Internalizing (B = 0.02; CI = 0.002, 0.05) and externalizing problems at follow-up (B = 0.01; CI = 0.0002, 0.03) were also indirectly affected by family HIV burden through caregiver depression. CONCLUSIONS: The data suggest that family HIV can affect child development, emphasizing the important role of depression in the pathway to such an effect. Community-based interventions directed at alleviating parental depression in the presence of HIV may help to interrupt the cycle of family HIV and adverse child outcomes.
Asunto(s)
Cuidadores/estadística & datos numéricos , Trastornos de la Conducta Infantil/etiología , Hijo de Padres Discapacitados/psicología , Salud de la Familia/estadística & datos numéricos , Infecciones por VIH/psicología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Cuidadores/psicología , Niño , Trastornos de la Conducta Infantil/epidemiología , Desarrollo Infantil , Preescolar , Depresión/epidemiología , Depresión/etiología , Femenino , Infecciones por VIH/epidemiología , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Humanos , Estudios Longitudinales , Malaui/epidemiología , Masculino , Persona de Mediana Edad , Calidad de Vida , Factores Socioeconómicos , Sudáfrica/epidemiología , Adulto JovenRESUMEN
Community-based organisations (CBOs) have the potential to provide high quality services for orphaned and vulnerable children in resource-limited settings. However, evidence is lacking as to whether CBOs are reaching those who are most vulnerable, whether attending these organisations is associated with greater psychosocial wellbeing, and how they might work. This study addressed these three questions using cross-sectional data from 1848 South African children aged 9-13. Data were obtained from the Young Carers and Child Community Care studies, which both investigated child wellbeing in South Africa using standardised self-report measures. Children from the Child Community Care study were all CBO attenders, whereas children from Young Carers were not receiving any CBO services, thereby serving as a comparison group. Multivariable regression analyses were used to test whether children attending CBOs were more deprived on socio-demographic variables (e.g., housing), and whether CBO attendance was in turn associated with better psychosocial outcomes (e.g., child depression). Mediation analysis was conducted to test whether more positive home environments mediated the association between CBO attendance and significantly higher psychological wellbeing. Overall, children attending CBOs did show greater vulnerability on most socio-demographic variables. For example, compared to children not attending any CBO, CBO-attending children tended to live in more crowded households (OR 1.22) and have been exposed to more community violence (OR 2.06). Despite their heightened vulnerability, however, children attending CBOs tended to perform better on psychosocial measures: for instance, showing fewer depressive symptoms (B=-0.33) and lower odds of experiencing physical (OR 0.07) or emotional abuse (OR 0.22). Indirect effects of CBO attendance on significantly higher child psychological wellbeing (lower depressive symptoms) was observed via lower rates of child abuse (B=-0.07) and domestic conflict/violence (B=-0.03) and higher rates of parental praise (B=-0.03). Null associations were observed between CBO attendance and severe psychopathology (e.g., suicidality). These cross-sectional results provide promising evidence regarding the potential success of CBO reach and impact but also highlight areas for improvement.
RESUMEN
The random sequential adsorption (RSA) problem holds crucial theoretical and practical significance, serving as a pivotal framework for understanding and optimizing particle packing in various scientific and technological applications. Here the problem of the one-dimensional RSA of k-mers onto a substrate with correlated defects controlled by uniform and power-law distributions is theoretically investigated: the coverage fraction is obtained as a function of the density of defects and several scaling laws are examined. The results are compared with extensive Monte Carlo simulations and more traditional methods based on master equations. Emphasis is given in elucidating the scaling behavior of the fluctuations of the coverage fraction. The phenomenon of universality breaking and the issues of conventional Gaussian fluctuations and the Lévy type fluctuations from a simple perspective, relying on the central limit theorem, are also addressed.
RESUMEN
In vivo Alzheimer's disease diagnosis and staging is traditionally based on clinical features. However, the agreement between clinical and pathological Alzheimer's disease diagnosis, whose diagnosis assessment includes amyloid and Braak histopathological tau staging, is not completely convergent. The development of positron emission tomography (PET) tracers targeting neurofibrillary tangles offers prospects for advancing the staging of Alzheimer's disease from both biological and clinical perspectives. Recent advances in radiochemistry made it possible to apply the postmortem Braak staging framework to tau-PET images obtained in vivo. Here, our aim is to provide a narrative review of the current literature on the relationship between Alzheimer's disease clinical features and the PET-based Braak staging framework. Overall, the available studies support the stepwise increase in disease severity following the advance of PET-based Braak stages, with later stages being associated with worse cognitive and clinical symptoms. In line with this, there is a trend for unimpaired cognition, mild cognitive impairment, and Alzheimer's disease dementia to be compatible with early, intermediate, and late patterns of tau deposition based on PET-based Braak stages. Moreover, neuropsychiatric symptom severity seems to be linked to the extent of tau-PET signal across Braak areas. In sum, this framework seems to correspond well with the clinical progression of Alzheimer's disease, which is an indication of its potential utility in research and clinical practice, especially for detecting preclinical tau levels in individuals without symptoms. However, further research is needed to improve the generalizability of these findings and to better understand the applications of this staging framework.