Functional connectivity is linked to working memory differences in children with reading learning disability.

Reading learning disability (RLD) is characterized by a specific difficulty in learning to read that is not better explained by an intellectual disability, lack of instruction, psychosocial adversity, or a neurological disorder. According to the domain-general hypothesis, a working memory deficit is the primary problem. Working memory in this population has recently been linked to altered resting-state functional connectivity within the default mode network (DMN), salience network (SN), and frontoparietal network (FPN) compared to that in typically developing individuals. The main purpose of the present study was to compare the within-network functional connectivity of the DMN, SN, FPN, and reading network in two groups of children with RLD: a group with lower-than-average working memory (LWM) and a group with average working memory (AWM). All subjects underwent resting-state functional magnetic resonance imaging (fMRI), and data were analyzed from a network perspective using the network brain statistics framework. The results showed that the LWM group had significantly weaker connectivity in a network that involved brain regions in the DMN, SN, and FPN than the AWM group. Although there was no significant difference between groups in reading network in the present study, other studies have shown relationship of the connectivity of the angular gyrus, supramarginal gyrus, and inferior parietal lobe with the phonological process of reading. The results suggest that although there are significant differences in functional connectivity in the associated networks between children with LWM and AWM, the distinctive cognitive profile has no specific effect on the reading network.

Competitive assembly resolves the stoichiometry of essential proteins in infectious HIV-1 virions.

During assembly on the plasma membrane, HIV-1 virions incorporate Gag-Pol as well as gp120/gp41 trimers. The Pol region consists of protease, reverse transcriptase and integrase precursors which are essential enzymes required for maturation, reverse transcription, and integration of the viral genome in the next host. gp120/gp41 trimers catalyze the fusion of the virion with its next host. Only a fraction of released virions are infectious. The stoichiometry of gp120/gp41 and Gag-Pol proteins in HIV virions was previously measured using cryotomography and ratiometric protein analysis, but what is the stoichiometry of these proteins in infectious virions remained to be determined. Here we developed a method based on competition between infectious HIV backbones with noninfectious mutants and measured 100 ± 10 Gag-Pol and 15 ± 3 gp120/gp41 proteins incorporated in infectious virions assembled in HEK293 cells from NL4.3 HIV-1 backbone. Our measurements are in broad agreement with cryotomography and ratiometric protein analysis and therefore stoichiometry of gp120/gp41 and Gag-Pol in infectious virions is the same as all released virions. With the development of appropriate mutants and infectivity assays, our method is applicable to other infectious viruses. Statement of significance: There are 30 million people who have succumbed to the AIDS pandemic with 600,000 additional deaths per year. HIV has an accelerated rate of mutational accumulation with the virus mutating out of neutralizing antibodies within the same patient making development of vaccines challenging. Like most enveloped viruses, only a fraction of released virions are infectious and the question of what selects these virions has remained a mystery. The method developed in this article will allow stoichiometric measurements on infectious virions and therefore allows further studies of causes of infectivity.

Tailoring/Tuning Properties of Polyester Urea-Urethanes through Hybridization with Titania Obtained Using the Sol-Gel Process.

Hybrid materials have been studied because in these materials the properties of organic components, such as elasticity and biodegradability, could be combined with the properties of inorganic components, such as good biological response, thereby transforming them into a single material with improved properties. In this work, Class I hybrid materials based on polyester-urea-urethanes and titania were obtained using the modified sol-gel method. This was corroborated using the FT-IR and Raman techniques which highlighted the formation of hydrogen bonds and the presence of Ti-OH groups in the hybrid materials. In addition, the mechanical and thermal properties and degradability were measured using techniques, such as Vickers hardness, TGA, DSC, and hydrolytic degradation; these properties could be tailored according to hybridization between both organic and inorganic components. The results show that Vickers hardness increased by 20% in hybrid materials as compared to polymers; also, the surface hydrophilicity increases in the hybrid materials, improving their cell viability. Furthermore, cytotoxicity in vitro test was carried out using osteoblast cells for intended biomedical applications and they showed non-cytotoxic behavior.

Effects of neurofeedback on the self-concept of children with learning disorders.

Children with learning disorders (LDs) often have a lower self-concept than their typically developing peers. Neurofeedback (NFB) treatments seem to improve the cognitive and academic performance of these children, but the effects on self-concept have not been studied. In this exploratory study, 34 right-handed children (8-11 y.o.) with LD and delayed electroencephalographic maturation responded to the Piers-Harris Children's Self-Concept Scale. One group received NFB (n = 20), and another group (n = 14) served as control, which included 9 children treated with sham-NFB and 5 on a waiting-list. A nonparametric permutation approach was used to compare the academic performance and self-concept difference (postscores - prescores) between the NFB and control groups. Given the smaller size of the control subgroups, a comparison of the percent changes between sham-NFB and the waiting-list was performed with the non-overlap of all pairs (NAP) technique. In the NFB group, the scores of reading, math, and global self-concept increased significantly, highlighting the self-concept subdomains of physical appearance, nonanxiety, popularity, and happiness. Additionally, the sham-NFB subgroup showed better outcomes than the waiting-list subgroup, perhaps due to noncontrolled factors. We found improved academic performance and self-concept in children with LDs who received NFB treatment. This study is an important exploratory step in studying a relevant treatment that seems to ameliorate symptoms of LDs such as anxiety and low self-concept.

Soil-Transmitted Helminthiasis in Children from a Rural Community Taking Part in a Periodic Deworming Program in the Peruvian Amazon.

Children in the Peruvian Amazon Basin are at risk of soil-transmitted helminths (STH) infections. This study aimed to determine the prevalence of STH infection in children from a rural Amazonian community of Peru and to elucidate epidemiological risk factors associated with its perpetuation while on a school-based deworming program with mebendazole. Stool samples of children aged 2-14 years and their mothers were analyzed through direct smear analysis, Kato-Katz, spontaneous sedimentation in tube, Baermann's method, and agar plate culture. A questionnaire was administered to collect epidemiological information of interest. Among 124 children, 25.8% had one or more STH. Individual prevalence rates were as follows: Ascaris lumbricoides, 16.1%; Strongyloides stercoralis, 10.5%; hookworm, 1.6%; and Trichuris trichiura, (1.6%). The prevalence of common STH (A. lumbricoides, T. trichiura, and hookworm) was higher among children aged 2-5 years than older children (31.6% versus 12.8%; P = 0.01). In terms of sanitation deficits, walking barefoot was significantly associated with STH infection (OR = 3.28; CI 95% = 1.11-12.07). Furthermore, STH-infected children more frequently had a mother who was concomitantly infected by STH than the non-STH-infected counterpart (36.4% versus 14.1%, P = 0.02). In conclusion, STH infection is highly prevalent in children from this Amazonian community despite routine deworming. Institutional health policies may include hygiene and sanitation improvements and screening/deworming of mothers to limit the dissemination of STH. Further studies are needed to address the social and epidemiological mechanics perpetuating these infections.

Synthesis and in Vitro Cytocompatibility of Segmented Poly(Ester-Urethane)s and Poly(Ester-Urea-Urethane)s for Bone Tissue Engineering.

Two series of segmented polyurethanes were obtained and their mechanical and thermal properties as well as their biodegradability and cytotoxicity were evaluated. The chemical nature of the polyurethanes was varied by using either 1,4 butanediol (poly-ester-urethanes, PEUs) or l-lysine ethyl ester dihydrochloride (poly-ester-urea-urethanes, PEUUs) as chain extenders. Results showed that varying the hard segment influenced the thermal and mechanical properties of the obtained polymers. PEUs showed strain and hardness values of about 10⁻20 MPa and 10⁻65 MPa, respectively. These values were higher than the obtained values for the PEUUs due to the phase segregation and the higher crystallinity observed for the polyester-urethanes (PEUs); phase segregation was also observed and analyzed by XRD and DSC. Moreover, both series of polymers showed hydrolytic degradation when they were submerged in PBS until 90 days with 20% of weight loss. In vitro tests using a Human Osteoblastic cell line (Hob) showed an average of 80% of cell viability and good adhesion for both series of polymers.

Relación entre apoyo social, estrés, ansiedad y depresión durante el embarazo en una población mexicana / Relationship between social support, stress, anxiety and depression during pregnancy in a specific mexican population

El propósito de la investigación es encontrar si hay diferencias significativas en los niveles de estrés, depresión y ansiedad entre mujeres embarazadas que perciben apoyo social y aquellas que no. A la par, conocer dichos niveles de ansiedad, depresión, estrés, y si la percepción de apoyo social incrementa o disminuye dependiendo del trimestre de embarazo, embarazos previos, ingesta de alcohol, ente otros factores externos. La muestra consistió en 227 mujeres embarazadas que visitaron un hospital o clínica privada. Se encontró que el apoyo social percibido, emocional y de confidencia está correlacionado significativamente con los niveles de ansiedad, estrés y depresión. Se encontró una correlación positiva entre el nivel de educación y el apoyo emocional percibido. Se detectaron diferencias entre los niveles de estrés, ansiedad y apoyo social entre mujeres que se encontraban embarazadas por primera vez y aquellas que tuvieron embarazos previos. Se halló una correlación positiva entre mujeres que tomaban alcohol durante el embarazo y la ansiedad, donde las que ingerían mayor cantidad presentaban niveles más altos de ansiedad. Al mismo tiempo, se demostró que el apoyo social de confidencia percibido se encuentra relacionado con ansiedad y depresión en una forma negativa

The purpose of the present research was to find if there is a significant difference in stress, depression and anxiety levels between pregnant women who perceived social support versus those who did not. Another aim was to analyse their levels of anxiety, depression and stress and whether perceived social support varied depending on the trimester of pregnancy, history of pregnancies, and alcohol intake, among other factors. The sample consisted of 227 pregnant women who attended a private hospital and medical clinic. It was found that perceived social, emotional, and confidential support are significantly correlated with levels of stress, anxiety and depression. There is a significant positive correlation between the level of education and perceived emotional, confidential and social support. Differences between levels of stress, anxiety, and social support were found between women who were pregnant for the first time and those who had been previously pregnant. A positive correlation was found between women who drank alcohol during pregnancy and anxiety, a higher alcohol intake showed higher levels of anxiety. Confidential social support was negatively correlated with anxiety and depression