Substantial reduction in child stunting is differentially associated to geographical and socioeconomic disparities in Misiones Province, Argentina.

OBJECTIVE: To estimate trends in the prevalence of child stunting in the population of children under 5 years of age covered by public health programmes, between 2009 and 2014 in Misiones, Argentina. METHODS: Using Bayesian model-based geostatistics, we evaluated 724 872 anthropometric measurements corresponding to 110 633 children. In order to identify disparities at local scale, we evaluated the hypotheses of a differential reduction of stunting according to the geographical location (at two-level spatial resolution) and to the socioeconomic level in a rural or urban environment. RESULTS: The prevalence of stunting had fallen significantly in the province overall. Sex and age defined gender disparities at individual level, and there were regional disparities with higher prevalence values in the north and northeast regions. In these areas, stunting decreased to a greater degree during the studied period, although the spatial pattern remained smoother. Stunting increased in peripheral urban and dispersed rural areas that are socioeconomically vulnerable. CONCLUSIONS: The spatial multi-level geostatistical estimates of child undernutrition provide a precision public health tool to target public policies to those populations with the greatest need, in order to reduce health disparities.

OBJECTIF: Estimer les tendances dans la prévalence du retard de croissance dans la population des enfants de moins de 5 ans couverts par les programmes de santé publique, entre 2009 et 2014 à Misiones, en Argentine. MÉTHODES: En utilisant la géostatistique basée sur un modèle bayésien, nous avons évalué 724.872 mesures anthropométriques correspondant à 110.633 enfants. Afin d'identifier les disparités à l'échelle locale, nous avons évalué les hypothèses d'une réduction différentielle du retard de croissance en fonction de la situation géographique (à une résolution spatiale à deux niveaux) et du niveau socioéconomique en milieu rural ou urbain. RÉSULTATS: La prévalence du retard de croissance avait considérablement diminué dans l'ensemble de la province. Le sexe et l'âge définissaient des disparités entre les sexes au niveau individuel, et il y avait des disparités régionales avec des valeurs de prévalence plus élevées dans les régions du nord et du nord-est. Dans ces régions, le retard de croissance a diminué plus fortement au cours de la période étudiée, bien que le modèle spatial soit resté plus lisse. Le retard de croissance a augmenté dans les zones urbaines périphériques et les zones rurales dispersées qui sont socioéconomiquement vulnérables. CONCLUSIONS: Les estimations géostatistiques spatiales à plusieurs niveaux de la sous-nutrition infantile fournissent un outil de santé publique de précision pour cibler les politiques publiques sur les populations qui en ont le plus besoin, afin de réduire les disparités en matière de santé.

On the Natural Structure of Amino Acid Patterns in Families of Protein Sequences.

All known terrestrial proteins are coded as continuous strings of ≈20 amino acids. The patterns formed by the repetitions of elements in groups of finite sequences describes the natural architectures of protein families. We present a method to search for patterns and groupings of patterns in protein sequences using a mathematically precise definition for "repetition", an efficient algorithmic implementation and a robust scoring system with no adjustable parameters. We show that the sequence patterns can be well-separated into disjoint classes according to their recurrence in nested structures. The statistics of the occurrences of patterns indicate that short repetitions are sufficient to account for the differences between natural families and randomized groups of sequences by more than 10 standard deviations, while contiguous sequence patterns shorter than 5 residues are effectively random in their occurrences. A small subset of patterns is sufficient to account for a robust "familiarity" definition between arbitrary sets of sequences.

Protein Repeats from First Principles.

Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family.

Genome-wide data (ChIP-seq) enabled identification of cell wall-related and aquaporin genes as targets of tomato ASR1, a drought stress-responsive transcription factor.

BACKGROUND: Identifying the target genes of transcription factors is important for unraveling regulatory networks in all types of organisms. Our interest was precisely to uncover the spectrum of loci regulated by a widespread plant transcription factor involved in physiological adaptation to drought, a type of stress that plants have encountered since the colonization of land habitats 400 MYA. The regulator under study, named ASR1, is exclusive to the plant kingdom (albeit absent in Arabidopsis) and known to alleviate the stress caused by restricted water availability. As its target genes are still unknown despite the original cloning of Asr1 cDNA 20 years ago, we examined the tomato genome for specific loci interacting in vivo with this conspicuous protein. RESULTS: We performed ChIP followed by high throughput DNA sequencing (ChIP-seq) on leaves from stressed tomato plants, using a high-quality anti-ASR1 antibody. In this way, we unraveled a novel repertoire of target genes, some of which are clearly involved in the response to drought stress. Many of the ASR1-enriched genomic loci we found encode enzymes involved in cell wall synthesis and remodeling as well as channels implicated in water and solute flux, such as aquaporins. In addition, we were able to determine a robust consensus ASR1-binding DNA motif. CONCLUSIONS: The finding of cell wall synthesis and aquaporin genes as targets of ASR1 is consistent with their suggested role in the physiological adaptation of plants to water loss. The results gain insight into the environmental stress-sensing pathways leading to plant tolerance of drought.

The role of pH fronts in reversible electroporation.

We present experimental measurements and theoretical predictions of ion transport in agar gels during reversible electroporation (ECT) for conditions typical to many clinical studies found in the literature, revealing the presence of pH fronts emerging from both electrodes. These results suggest that pH fronts are immediate and substantial. Since they might give rise to tissue necrosis, an unwanted condition in clinical applications of ECT as well as in irreversible electroporation (IRE) and in electrogenetherapy (EGT), it is important to quantify their extent and evolution. Here, a tracking technique is used to follow the space-time evolution of these pH fronts. It is found that they scale in time as t(½), characteristic of a predominantly diffusive process. Comparing ECT pH fronts with those arising in electrotherapy (EChT), another treatment applying constant electric fields whose main goal is tissue necrosis, a striking result is observed: anodic acidification is larger in ECT than in EChT, suggesting that tissue necrosis could also be greater. Ways to minimize these adverse effects in ECT are suggested.