Acquisition of Visuomotor Abilities and Intellectual Quotient in Children Aged 4–10 Years: Relationship with Micronutrient Nutritional Status

Lethargy, poor attention, and the high rate and severity of infections in malnourished children affect their educational achievement. We therefore studied the association between visuomotor abilities and intelligence quotient (IQ) and their relationship with iron, zinc, and copper. A cross-sectional study was carried out on a sample of 89 healthy children (age range, 4-10 years). Evaluations of visuomotor ability and IQ were performed with the Developmental Test of Visual Motor Integration (VMI) and the Scale for Measurement of Intelligence for children aged 3-18 years, respectively. Nutritional status was assessed using anthropometry and biochemical assessments, which included serum ferritin, zinc and copper levels, and Hb. The sample was classified as having low or normal VMI scores: 47 children (52.8%, mean age 7 +/- 1.5 years) had low VMI, and 42 (47.2%, mean age 7 +/- 2.06 years) had normal VMI. There were no statistically significant differences in socioeconomic and cultural condition between both groups. We found significantly higher serum copper and ferritin levels in normal as compared to low VMI, but we did not find any differences with zinc. IQ was significantly higher in normal vs low VMI children. The fact that children with abnormal VMI presented low mean serum copper and ferritin concentrations could indicate that copper and iron deficiencies in this sample could be related with visuomotor abilities.     

West Nile Virus Retinopathy and Associations with Long Term Neurological and Neurocognitive Sequelae

West Nile virus (WNV) has emerged as an important vector-borne pathogen in North America, with more than 3 million estimated to have been infected. Retinopathy from WNV infection has been previously reported in acute cases, though those prior reports did not evaluate the risk of retinopathy based on clinical severity of neurologic disease. The purpose of this cross-sectional study was to perform comprehensive ophthalmological and neurological examinations on 111 patients with a history of West Nile virus infection and describe the ocular manifestations. Out of 111 patients, 27 (24%) had evidence for West Nile virus associated retinopathy (WNVR); this observation was higher (49%) in those patients who initially presented with encephalitis. Individuals with WNVR had more frequent involvement of the macula and peripheral involvement compared to those patients without WNVR (p<0.05). WNVR was also associated with a greater likelihood of abnormal reflexes on neurological exam, poorer learning, greater dependence in activities of daily living, and lower quality of life (p<0.05). WNVR was seen more frequently in elderly patients (age > 60 years), and was associated with higher rates of diabetes mellitus and a history of encephalitis (p<0.05). A multivariable logistic regression revealed that only a history of encephalitis was independently associated with WNVR [Adjusted Odds Ratio = 4.9 (1.8–13.2); p = 0.001]. Our study found that WNVR occurs in one fourth of patients with a history of WNV infection and is more frequently observed in those with apparent severe neurological sequelae (e.g., encephalitis). The clinical relevance of WNVR was supported by its associations with dependence in activities of daily living and lower quality of life. This unique evaluation of WNV patients included fundoscopic examinations and their associations with neurologic impairment. Our findings can be used during ophthalmological consultation for the evaluation, treatment and rehabilitation phases of care for WNV patients.     

Minimizing the Electrolyte Volume in Li–S Batteries: A Step Forward to High Gravimetric Energy Density

Sulfur electrodes confined in an inert carbon matrix show practical limitations and concerns related to low cathode density. As a result, these electrodes require a large amount of electrolyte, normally three times more than the volume used in commercial Li‐ion batteries. Herein, a high‐energy and high‐performance lithium–sulfur battery concept, designed to achieve high practical capacity with minimum volume of electrolyte is proposed. It is based on deposition of polysulfide species on a self‐standing and highly conductive carbon nanofiber network, thus eliminating the need for a binder and current collector, resulting in high active material loading. The fiber network has a functionalized surface with the presence of polar oxygen groups, with the aim to prevent polysulfide migration to the lithium anode during the electrochemical process, by the formation of S–O species. Owing to the high sulfur loading (6 mg cm^?2) and a reduced free volume of the sulfide/fiber electrode, the Li–S cell is designed to work with as little as 10 µL cm^?2 of electrolyte. With this design the cell has a high energy density of 450 Wh kg^?1, a lifetime of more than 400 cycles, and the possibility of low cost, by use of abundant and eco‐friendly materials.     

TfVPS32 Regulates Cell Division in the Parasite Tritrichomonas foetus

The flagellated protist Tritrichomonas foetus is a parasite that causes bovine trichomonosis, a major sexually transmitted disease in cattle. Cell division has been described as a key player in controlling cell survival in other cells, including parasites but there is no information on the regulation of this process in T. foetus. The regulation of cytokinetic abscission, the final stage of cell division, is mediated by members of the ESCRT (endosomal sorting complex required for transport) machinery. VPS32 is a subunit within the ESCRTIII complex and here, we report that TfVPS32 is localized on cytoplasmic vesicles and a redistribution of the protein to the midbody is observed during the cellular division. In concordance with its localization, deletion of TfVPS32 C‐terminal alpha helices (α5 helix and/or α4‐5 helix) leads to abnormal T. foetus growth, an increase in the percentage of multinucleated parasites and cell cycle arrest at G2/M phase. Together, these results indicate a role of this protein in controlling normal cell division.     

Toward a common aggregation mechanism for a β-barrel protein family: Insights derived from a stable dimeric species

Δ78Δ is a second generation functional all-β sheet variant of IFABP (intestinal fatty acid binding protein) corresponding to the fragment 29–106 of the parent protein. This protein and its predecessor, Δ98Δ (segment 29–126 of IFABP), were initially uncovered by controlled proteolysis. Remarkably, although IFABP and Δ98Δ are monomers in solution, Δ78Δ adopts a stable dimeric structure. With the aim of identifying key structural features that modulate the aggregation of β-proteins, we evaluate here the structure and aggregation propensity of Δ78Δ. The 2,2,2-trifluoroethanol (TFE) induced aggregation of this protein shows a primary nucleation–elongation mechanism, characterized by the stabilization of a dimeric nucleus. Its rate of production from the co-solvent induced aggregation prone state governs the kinetics of polymerization. In this context, the value of Δ78Δ lies in the fact that – being a stable dimeric species – it reduces an otherwise bimolecular reaction to a unimolecular one. Interestingly, even though Δ78Δ and IFABP display similar conformational stability, the abrogated form of IFABP shows an enhanced aggregation rate, revealing the ancillary role played on this process by the free energy of the native proteins. Δ78Δ share with IFABP and Δ98Δ a common putative aggregation-prone central peptide. Differences in the exposure/accessibility of this segment dictated by the environment around this region might underlie the observed variations in the speed of aggregation. Lessons learnt from this natural dimeric protein might shed light on the early conformational events leading to β-conversion from barrels to amyloid aggregates.     

Altruism and fairness: Unnatural selection?

Darwin admitted that the evolution of moral phenomena such as altruism and fairness, which are usually in opposition to the maximization of individual reproductive success, was not easily accounted for by natural selection. Later, authors have proposed additional mechanisms, including kin selection, inclusive fitness, and reciprocal altruism. In the present work, we explore the extent to which sexual selection has played a role in the appearance of human moral traits. It has been suggested that because certain moral virtues, including altruism and kindness, are sexually attractive, their evolution could have been shaped by the process of sexual selection. Our review suggests that although it is possible that sexual selection played such a role, it is difficult to determine the extent of its relevance, the specific form of this influence, and its interplay with other evolutionary mechanisms.     

Allocation of biomass and photoassimilates in juvenile plants of six Patagonian species in response to five water supply regimes

Background and Aims

The growth–differentiation balance hypothesis (GDBH) states that there is a physiological trade-off between growth and secondary metabolism and predicts a parabolic effect of resource availability (such as water or nutrients) on secondary metabolite production. To test this hypothesis, the response of six Patagonian Monte species (Jarava speciosa, Grindelia chiloensis, Prosopis alpataco, Bougainvillea spinosa, Chuquiraga erinacea and Larrea divaricata) were investigated in terms of total biomass and resource allocation patterns in response to a water gradient.

Methods

One-month-old seedlings were subjected to five water supply regimes (expressed as percentage dry soil weight: 13 %, 11 %, 9 %, 7 % or 5 % – field water capacity being 15 %). After 150 d, plants were harvested, oven-dried and partitioned into root, stem and leaf. Allometric analysis was used to correct for size differences in dry matter partitioning. Determinations of total phenolics (TP), condensed tannins (CT), nitrogen (N) and total non-structural carbohydrates (TNC) concentrations were done on each fraction. Based on concentrations and biomass data, contents of TP and CT were estimated for whole plants, and graphical vector analysis was applied to interpret drought effect.

Key Results

Four species (J. speciosa, G. chiloensis, P. alpataco and B. spinosa) showed a decrease in total biomass in the 5 % water supply regime. Differences in dry matter partitioning among treatments were mainly due to size variation. Concentrations of TP, CT, N and TNC varied little and the effect of drought on contents of TP and CT was not adequately predicted by the GDBH, except for G. chiloensis.

Conclusions

Water stress affected growth-related processes (i.e. reduced total biomass) rather than defence-related secondary metabolism or allocation to different organs in juvenile plants. Therefore, the results suggest that application of the GDBH to plants experiencing drought-stress should be done with caution, at least for Patagonian Monte species.     

Soil phytoliths as evidence for species replacement in grazed rangelands of central Argentina

Rangeland utilization for livestock production in central Argentina has apparently resulted in the replacement of preferred mid-grasses ( Poa ligularis and Stipa clarazii ) by preferred short-grasses ( Piptochaetium napostaense and Stipa tenuis ) and avoided grasses ( Stipa tenuissima and Stipa eriostachya ). However, the botanical composition in the pristine condition is unknown due to the lack of historical data and relict areas. The objective of this study was to analyze soil phytolith assemblages from a representative site of central Argentina rangelands to test the presumed floristic changes. Soil phytolith assemblages (SPAs) were compared with three plant phytolith assemblages (PPAs), each of it made up of two species. One PPA was integrated by the preferred mid-grasses P. ligularis and S. clarazii , another by the preferred short-grasses P. napostaense and S. tenuis , and a third one by the avoided grasses S. eriostachya and S. tenuissima . For each PPA, the proportion of species representing the best fit with SPAs was estimated by considering all possible lineal combinations between the phytolith assemblage of the two integrating species, and selecting that representing the minimum distance to SPA. The highest degree of similarity between SPAs and PPAs corresponded to the PPA integrated by P. ligularis and S. clarazii . Our results support the hypothesis of the dominance of preferred mid-grasses in the pristine condition in rangelands of central Argentina, and that a shift towards the dominance of preferred short-grasses and avoided grasses has occurred in its present disturbed condition.