Dorsolateral Prefrontal Transcranial Direct Current Stimulation Modulates Language Processing but Does Not Facilitate Overt Second Language Word Production.

Word retrieval in bilingual speakers partly depends on executive control systems in the left prefrontal cortex - including dorsolateral prefrontal cortex (DLPFC). We tested the hypothesis that DLPFC modulates word production of words specifically in a second language (L2) by measuring the effects of anodal transcranial direct current stimulation (anodal-tDCS) over the DLPFC on picture naming and word translation and on event-related potentials (ERPs) and their sources. Twenty-six bilingual participants with "unbalanced" proficiency in two languages were given 20 min of 1.5 mA anodal or sham tDCS (double-blind stimulation design, counterbalanced stimulation order, 1-week intersession delay). The participants then performed the following tasks: verbal and non-verbal fluency during anodal-tDCS stimulation and first and second language (L1 and L2) picture naming and translation [forward (L1 → L2) and backward (L2 → L1)] immediately after stimulation. The electroencephalogram (EEG) was recorded during picture naming and translation. On the behavioral level, anodal-tDCS had an influence on non-verbal fluency but neither on verbal fluency, nor on picture naming and translation. EEG measures revealed significant interactions between Language and Stimulation on picture naming around 380 ms post-stimulus onset and Translation direction and Stimulation on translation around 530 ms post-stimulus onset. These effects suggest that L2 phonological retrieval and phoneme encoding are spatially and temporally segregated in the brain. We conclude that anodal-tDCS stimulation has an effect at a neural level on phonological processes and, critically, that DLPFC-mediated activation is a constraint on language production specifically in L2

Quantitative test of the barrier nucleosome model for statistical positioning of nucleosomes up- and downstream of transcription start sites

The positions of nucleosomes in eukaryotic genomes determine which parts of the DNA sequence are readily accessible for regulatory proteins and which are not. Genome-wide maps of nucleosome positions have revealed a salient pattern around transcription start sites, involving a nucleosome-free region (NFR) flanked by a pronounced periodic pattern in the average nucleosome density. While the periodic pattern clearly reflects well-positioned nucleosomes, the positioning mechanism is less clear. A recent experimental study by Mavrich et al. argued that the pattern observed in S. cerevisiae is qualitatively consistent with a `barrier nucleosome model', in which the oscillatory pattern is created by the statistical positioning mechanism of Kornberg and Stryer. On the other hand, there is clear evidence for intrinsic sequence preferences of nucleosomes, and it is unclear to what extent these sequence preferences affect the observed pattern. To test the barrier nucleosome model, we quantitatively analyze yeast nucleosome positioning data both up- and downstream from NFRs. Our analysis is based on the Tonks model of statistical physics which quantifies the interplay between the excluded-volume interaction of nucleosomes and their positional entropy. We find that although the typical patterns on the two sides of the NFR are different, they are both quantitatively described by the same physical model, with the same parameters, but different boundary conditions. The inferred boundary conditions suggest that the first nucleosome downstream from the NFR (the +1 nucleosome) is typically directly positioned while the first nucleosome upstream is statistically positioned via a nucleosome-repelling DNA region. These boundary conditions, which can be locally encoded into the genome sequence, significantly shape the statistical distribution of nucleosomes over a range of up to ~1000 bp to each side.Comment: includes supporting materia

The role of multiple marks in epigenetic silencing and the emergence of a stable bivalent chromatin state

We introduce and analyze a minimal model of epigenetic silencing in budding yeast, built upon known biomolecular interactions in the system. Doing so, we identify the epigenetic marks essential for the bistability of epigenetic states. The model explicitly incorporates two key chromatin marks, namely H4K16 acetylation and H3K79 methylation, and explores whether the presence of multiple marks lead to a qualitatively different systems behavior. We find that having both modifications is important for the robustness of epigenetic silencing. Besides the silenced and transcriptionally active fate of chromatin, our model leads to a novel state with bivalent (i.e., both active and silencing) marks under certain perturbations (knock-out mutations, inhibition or enhancement of enzymatic activity). The bivalent state appears under several perturbations and is shown to result in patchy silencing. We also show that the titration effect, owing to a limited supply of silencing proteins, can result in counter-intuitive responses. The design principles of the silencing system is systematically investigated and disparate experimental observations are assessed within a single theoretical framework. Specifically, we discuss the behavior of Sir protein recruitment, spreading and stability of silenced regions in commonly-studied mutants (e.g., sas2, dot1) illuminating the controversial role of Dot1 in the systems biology of yeast silencing.Comment: Supplementary Material, 14 page

Family Outcomes After the Pediatric Intensive Care Unit: A Scoping Review

Background: Intensivists are increasingly attuned to the post-discharge outcomes experienced by families because patient recovery and family outcomes are interdependent after childhood critical illness. In this scoping review of international contemporary literature, we describe the evidence of family effects and functioning post-PICU as well as outcome measures used in order to identify strengths and weaknesses in the literature.Methods: We reviewed all articles published between 1970 and 2017 in PubMed, EMBASE, PsycINFO, Cumulative Index of Nursing and Allied Health Literature (CINAHL), or the Cochrane Controlled Trials Registry. Our search used a combination of terms for the concept of “critical care/illness” combined with additional terms for the pre-specified domains of social, cognitive, emotional, physical, health-related quality of life (HRQL), and family functioning.Results: We identified 71 articles reporting on the post-PICU experience of more than 2,400 parents and 3,600 families of PICU survivors in 8 countries. These articles used 101 different metrics to assess the various aspects of family outcomes; 34 articles also included open-ended interviews. Overall, most families experienced significant disruption in at least 5 out of 6 of our family outcomes subdomains, with themes of decline in mental health, physical health, family cohesion, and family finances identified. Almost all articles represented relatively small, single-center or disease-specific observational studies. There was disproportionate representation of families of higher socioeconomic status and Caucasian race, and there was much more data about mothers compared to fathers. There was also very limited information regarding outcomes for siblings and extended family members after a child’s PICU stay. Conclusions: Significant opportunities remain for research exploring family functioning after PICU discharge. We recommend that future work include more diverse populations with respect to the critically ill child as well as family characteristics, include more intervention studies, and enrich existing knowledge about outcomes for siblings and extended family

Vigilancia epidemiológica de Leishmaniasis en una zona no endémica

La Leishmaniasis, es una de las enfermedades tropicales desatendidas, de denuncia obligatoria en medicina de pequeños animales (Normativa Ministerio de Salud de la Nación)[1]. Esta infección es endémica en las Provincias de Misiones, Corrientes, Entre Ríos, Chaco, Santiago del Estero, Formosa y Salta, desde el año 2006. En el ámbito urbano el canino doméstico (Canis familiaris) constituye el principal reservorio para la infección humana. La Leishmaniasis Visceral humana (LV) afecta principalmente a niños de 0 a 15 años, mayores de 65 años, e individuos inmunodeficientes. Entre otros factores, las migraciones poblacionales y el cambio climático contribuyen a la expansión de las enfermedades transmitidas por vectores. Mantener vigilancia en animales centinela, en áreas vulnerables con elevados índices migratorios, es un excelente recurso a fin de realizar alertas e intervenciones tempranas ante la posibilidad de circulación (aún solapada) del agente y sus hospedadores intermediarios. Objetivos: Investigar la presencia de protozoos del Complejo Leishmania donovani en un área centinela de la Provincia de Buenos Aires.Facultad de Ciencias Veterinaria

Vigilancia epidemiológica de Leishmaniasis en una zona no endémica

La Leishmaniasis, es una de las enfermedades tropicales desatendidas, de denuncia obligatoria en medicina de pequeños animales (Normativa Ministerio de Salud de la Nación)[1]. Esta infección es endémica en las Provincias de Misiones, Corrientes, Entre Ríos, Chaco, Santiago del Estero, Formosa y Salta, desde el año 2006. En el ámbito urbano el canino doméstico (Canis familiaris) constituye el principal reservorio para la infección humana. La Leishmaniasis Visceral humana (LV) afecta principalmente a niños de 0 a 15 años, mayores de 65 años, e individuos inmunodeficientes. Entre otros factores, las migraciones poblacionales y el cambio climático contribuyen a la expansión de las enfermedades transmitidas por vectores. Mantener vigilancia en animales centinela, en áreas vulnerables con elevados índices migratorios, es un excelente recurso a fin de realizar alertas e intervenciones tempranas ante la posibilidad de circulación (aún solapada) del agente y sus hospedadores intermediarios. Objetivos: Investigar la presencia de protozoos del Complejo Leishmania donovani en un área centinela de la Provincia de Buenos Aires.Facultad de Ciencias Veterinaria

Patterns and Mechanisms of Ancestral Histone Protein Inheritance in Budding Yeast

Tracking of ancestral histone proteins over multiple generations of genome replication in yeast reveals that old histones move along genes from 3′ toward 5′ over time, and that maternal histones move up to around 400 bp during genomic replication

Vigilancia epidemiológica de Leishmaniasis en una zona no endémica

La Leishmaniasis, es una de las enfermedades tropicales desatendidas, de denuncia obligatoria en medicina de pequeños animales (Normativa Ministerio de Salud de la Nación)[1]. Esta infección es endémica en las Provincias de Misiones, Corrientes, Entre Ríos, Chaco, Santiago del Estero, Formosa y Salta, desde el año 2006. En el ámbito urbano el canino doméstico (Canis familiaris) constituye el principal reservorio para la infección humana. La Leishmaniasis Visceral humana (LV) afecta principalmente a niños de 0 a 15 años, mayores de 65 años, e individuos inmunodeficientes. Entre otros factores, las migraciones poblacionales y el cambio climático contribuyen a la expansión de las enfermedades transmitidas por vectores. Mantener vigilancia en animales centinela, en áreas vulnerables con elevados índices migratorios, es un excelente recurso a fin de realizar alertas e intervenciones tempranas ante la posibilidad de circulación (aún solapada) del agente y sus hospedadores intermediarios. Objetivos: Investigar la presencia de protozoos del Complejo Leishmania donovani en un área centinela de la Provincia de Buenos Aires.Facultad de Ciencias Veterinaria

Vigilancia epidemiológica de Leishmaniasis en una zona no endémica

Se trabajó en los Barrios Piria, Villa Rubencito, El Zanjón y El Molino de la Localidad de Ensenada,utilizando a los caninos como bioindicadores. Se realizaron observaciones dérmicas para identificar lesiones cutáneas compatibles con la enfermedad. En aquellas lesiones compatibles se realizaron improntas y se colorearon con Giemsa para su observación al microscopio óptico. Por otra parte, se analizaron muestras de suero sanguíneo de 100 caninos de entre 4 y 8 años, sin distinción de sexo y raza, con y sin lesiones compatibles con Leishmaniasis. Las muestras se extrajeron por punción venosa, con el consentimiento de sus propietarios. Los sueros se procesaron mediante la técnica inmunocromatográfica (IC) Kalazar Detect, Canine Prueba Rápida, para la detección de anticuerpos contra Leishmania infantum-chagasi. Este es un método serológico indirecto cualitativo, que utiliza alantígeno recombinante Rk39 para la detección de anticuerpos dirigidos hacia miembros del complejo L. donovani. Cada placa inmunocromatográfica se leyó dentro de los 10 minutos de colocado el suero,como lo indica el equipo.Fil: Mastrantonio Pedrina, Franca Lucrecia. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Manfredi, Mauro Joaquin. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Paladini, Antonela. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Butti, Marcos Javier. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Raimondi, I.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Burgos, Lola. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Gamboa, María Inés. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Corbalán, Valeria Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Osen, Beatriz Amelia. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Monzón, R.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Casas, N.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; Argentina. Ministerio de Salud de la Nación; ArgentinaFil: Salomón, Oscar Daniel. Centro de Estudios Etnograficos En Colabor ; Facultad de Humanidades ; Universidad Nacional del Nordeste; . Secretaria de Gobierno de Salud. Instituto Nacional de Medicina Tropical. Instituto Nacional de Medicina Tropical - Sede Tucumán; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Radman, Nilda Ester. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; Argentin

Ultraviolet mutagenesis and inducible DNA repair in Caulobacter crescentus

The ability to reactivate ultraviolet (UV) damaged phage ΦCbK (W-reactivation) is induced by UV irradiation of Caulobacter crescentus cells. Induction of W-reactivation potential is specific for phage ΦCbK, requires protein synthesis, and is greatly reduced in the presence of the rec-526 mutation. The induction signal generated by UV irradiation is transient, lasting about 1 1/2–2 h at 30°C; if chloramphenicol is present during early times after UV irradiation, induction of W-reactivation does not occur. Induction is maximal when cells are exposed to 5–10 J/m 2 of UV, a dose that also results in considerable mutagenesis of the cells. Taken together, these observations demonstrate the existence of a UV inducible, protein synthesis requiring, transiently signalled, rec -requiring DNA repair system analogous to W-reactivation in Escherichia coli . In addition, C. crescentus also has an efficient photoreactivation system that reverses UV damage in the presence of strong visible light.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47557/1/438_2004_Article_BF00329935.pd