Electrostatic potentials of atomic nanostructures at metal surfaces quantified by scanning quantum dot microscopy.

The discrete and charge-separated nature of matter - electrons and nuclei - results in local electrostatic fields that are ubiquitous in nanoscale structures and relevant in catalysis, nanoelectronics and quantum nanoscience. Surface-averaging techniques provide only limited experimental access to these potentials, which are determined by the shape, material, and environment of the nanostructure. Here, we image the potential over adatoms, chains, and clusters of Ag and Au atoms assembled on Ag(111) and quantify their surface dipole moments. By focusing on the total charge density, these data establish a benchmark for theory. Our density functional theory calculations show a very good agreement with experiment and allow a deeper analysis of the dipole formation mechanisms, their dependence on fundamental atomic properties and on the shape of the nanostructures. We formulate an intuitive picture of the basic mechanisms behind dipole formation, allowing better design choices for future nanoscale systems such as single-atom catalysts.

Identification of RP1 as the genetic cause of retinitis pigmentosa in a multi-generational pedigree using Extremely Low-Coverage Whole Genome Sequencing (XLC-WGS).

MOTIVATION: Next-generation sequencing (NGS) technologies are decisive for discovering disease-causing variants, although their cost limits their utility in a clinical setting. A cost-mitigating alternative is an extremely low coverage whole-genome sequencing (XLC-WGS). We investigated its use to identify causal variants within a multi-generational pedigree of individuals with retinitis pigmentosa (RP). Causing progressive vision loss, RP is a group of genetically heterogeneous eye disorders with approximately 60 known causal genes. RESULTS: We performed XLC-WGS in seventeen members of this pedigree, including three individuals with a confirmed diagnosis of RP. Sequencing data were processed using Illumina's DRAGEN pipeline and filtered using Illumina's genotype quality score metric (GQX). The resulting variants were analyzed using Expert Variant Interpreter (eVai) from enGenome as a prioritization tool. A nonsense known mutation (c.1625C > G; p.Ser542*) in exon 4 of the RP1 gene emerged as the most likely causal variant. We identified two homozygous carriers of this variant among the three sequenced RP cases and three heterozygous individuals with sufficient coverage of the RP1 locus. Our data show the utility of combining pedigree information with XLC-WGS as a cost-effective approach to identify disease-causing variants.

Analysis of the MCTP Amino Acid Sequence Reveals the Conservation of Putative Calcium- and Lipid-Binding Pockets Within the C2 Domains In Silico.

MCTPs (Multiple C2 Domains and Transmembrane region Proteins) are evolutionarily and structurally related to other C2 proteins, which are central to exocytosis and membrane trafficking; however, their specific function has been little studied. MCTPs are associated with endosomes and the endoplasmic reticulum and possess three C2 domains (C2A-C2C) and two transmembrane regions (TMRs) well conserved in different species. Here, we generated structural models of the MCTP C2 domains of C. elegans and analyzed their putative function by docking, which revealed that these domains possess Ca2+- and lipid-binding pockets, suggesting that MCTPs play a significant, calcium-dependent role in membrane physiology.

Multiomic identification of factors associated with progression to cystic kidney disease in mice with nephron Ift88 disruption.

Ift88 gene mutations cause primary cilia loss and polycystic kidney disease (PKD) in mice. Nephron intraflagellar transport protein 88 (Ift88) knockout (KO) at 2 mo postnatal does not affect renal histology at 4 mo postnatal and causes PKD only in males by 11 mo postnatal. To identify factors associated with PKD development, kidneys from 4-mo-old male and female control and Ift88 KO mice underwent transcriptomic, proteomic, Western blot, metabolomic, and lipidomic analyses. mRNAs involved in extracellular matrix (ECM) synthesis and degradation were selectively upregulated in male KO mice. Proteomic analysis was insufficiently sensitive to detect most ECM components, while Western blot analysis paradoxically revealed reduced fibronectin and collagen type I in male KO mice. Only male KO mice had upregulated mRNAs encoding fibrinogen subunits and receptors for vascular endothelial growth factor and platelet-derived growth factor; period 2, period 3, and nuclear receptor subfamily 1 group D member 1 clock mRNAs were selectively decreased in male KO mice. Proteomic, metabolomic, and lipidomic analyses detected a relative (vs. the same-sex control) decrease in factors involved in fatty acid ß-oxidation in female KO mice, while increased or unchanged levels in male KO mice, including medium-chain acyl-CoA dehydrogenase, 3-hydroxybutyrate, and acylcarnitine. Three putative mRNA biomarkers of cystogenesis in male Ift88 KO mice (similar control levels between sexes and uniquely altered by KO in males) were identified, including high levels (fibrinogen α-chain and stromal cell-derived factor 2-like 1) and low levels (BTG3-associated nuclear protein) in male KO mice. These findings suggest that relative alterations in renal ECM metabolism, fatty acid ß-oxidation, and other pathways precede cystogenesis in Ift88 KO mice. In addition, potential novel biomarkers of cystogenesis in Ift88 KO mice have been identified.NEW & NOTEWORTHY Male, but not female, mice with nephron intraflagellar transport protein 88 (Ift88) gene knockout (KO) develop polycystic kidneys by ∼1 yr postnatal. We performed multiomic analysis of precystic male and female Ift88 KO and control kidneys. Precystic male Ift88 KO mice exhibited differential alterations (vs. females) in mRNA, proteins, metabolites, and/or lipids associated with renal extracellular matrix metabolism, fatty acid ß-oxidation, circadian rhythm, and other pathways. These findings suggest targets for evaluation in the pathogenesis of Ift88 KO polycystic kidneys.

Comparing UAV-Based Technologies and RGB-D Reconstruction Methods for Plant Height and Biomass Monitoring on Grass Ley.

Pastures are botanically diverse and difficult to characterize. Digital modeling of pasture biomass and quality by non-destructive methods can provide highly valuable support for decision-making. This study aimed to evaluate aerial and on-ground methods to characterize grass ley fields, estimating plant height, biomass and volume, using digital grass models. Two fields were sampled, one timothy-dominant and the other ryegrass-dominant. Both sensing systems allowed estimation of biomass, volume and plant height, which were compared with ground truth, also taking into consideration basic economical aspects. To obtain ground-truth data for validation, 10 plots of 1 m² were manually and destructively sampled on each field. The studied systems differed in data resolution, thus in estimation capability. There was a reasonably good agreement between the UAV-based, the RGB-D-based estimates and the manual height measurements on both fields. RGB-D-based estimation correlated well with ground truth of plant height ( R 2 > 0.80 ) for both fields, and with dry biomass ( R 2 = 0.88 ), only for the timothy field. RGB-D-based estimation of plant volume for ryegrass showed a high agreement ( R 2 = 0.87 ). The UAV-based system showed a weaker estimation capability for plant height and dry biomass ( R 2 < 0.6 ). UAV-systems are more affordable, easier to operate and can cover a larger surface. On-ground techniques with RGB-D cameras can produce highly detailed models, but with more variable results than UAV-based models. On-ground RGB-D data can be effectively analysed with open source software, which is a cost reduction advantage, compared with aerial image analysis. Since the resolution for agricultural operations does not need fine identification the end-details of the grass plants, the use of aerial platforms could result a better option in grasslands.

A Low-Cost Approach to Automatically Obtain Accurate 3D Models of Woody Crops.

Crop monitoring is an essential practice within the field of precision agriculture since it is based on observing, measuring and properly responding to inter- and intra-field variability. In particular, "on ground crop inspection" potentially allows early detection of certain crop problems or precision treatment to be carried out simultaneously with pest detection. "On ground monitoring" is also of great interest for woody crops. This paper explores the development of a low-cost crop monitoring system that can automatically create accurate 3D models (clouds of coloured points) of woody crop rows. The system consists of a mobile platform that allows the easy acquisition of information in the field at an average speed of 3 km/h. The platform, among others, integrates an RGB-D sensor that provides RGB information as well as an array with the distances to the objects closest to the sensor. The RGB-D information plus the geographical positions of relevant points, such as the starting and the ending points of the row, allow the generation of a 3D reconstruction of a woody crop row in which all the points of the cloud have a geographical location as well as the RGB colour values. The proposed approach for the automatic 3D reconstruction is not limited by the size of the sampled space and includes a method for the removal of the drift that appears in the reconstruction of large crop rows.

Merge Fuzzy Visual Servoing and GPS-Based Planning to Obtain a Proper Navigation Behavior for a Small Crop-Inspection Robot.

The concept of precision agriculture, which proposes farming management adapted to crop variability, has emerged in recent years. To effectively implement precision agriculture, data must be gathered from the field in an automated manner at minimal cost. In this study, a small autonomous field inspection vehicle was developed to minimise the impact of the scouting on the crop and soil compaction. The proposed approach integrates a camera with a GPS receiver to obtain a set of basic behaviours required of an autonomous mobile robot to inspect a crop field with full coverage. A path planner considered the field contour and the crop type to determine the best inspection route. An image-processing method capable of extracting the central crop row under uncontrolled lighting conditions in real time from images acquired with a reflex camera positioned on the front of the robot was developed. Two fuzzy controllers were also designed and developed to achieve vision-guided navigation. A method for detecting the end of a crop row using camera-acquired images was developed. In addition, manoeuvres necessary for the robot to change rows were established. These manoeuvres enabled the robot to autonomously cover the entire crop by following a previously established plan and without stepping on the crop row, which is an essential behaviour for covering crops such as maize without damaging them.

Molecular characterization and antifungal susceptibility of Cryptococcus neoformans strains collected from a single institution in Lima, Peru / Caracterización molecular y sensibilidad antifúngica de cepas de Cryptococcus neoformans provenientes de una institución de Lima, Perú

Background: Cryptococcosis is a fungal infection with a worldwide distribution, mainly caused by Cryptococcus neoformans and Cryptococcus gattii. Aims: To molecularly characterize the mating-types, serotypes, genotypes and antifungal susceptibility profiles of a set of retrospectively isolated C. neoformans strains from Lima, Peru. Methods: A set of 32 Cryptococcus spp. strains from the Institute of Tropical Medicine of the National University of San Marcos, Lima, Peru, were included in this retrospective study. Twenty-four strains were isolated from patients, while the remaining 8 were isolated from the environment. Results: Using conventional PCR, 27 (84.4%) of the isolates were identified as C. neoformans var. grubii mating-type alpha and serotype A. Using the AFLP fingerprinting, it was shown that 16 (50%) of the C. neoformans strains were genotype AFLP1, 13 (40.6%) were genotype AFLP1B, 2 (6.3%) were genotype AFLP2, and 1 (3.1%) was found to be a hybrid between both C. neoformans varieties (genotype AFLP3). The antifungal susceptibility profiles for amphotericin B, fluconazole and voriconazole showed that all the 32 C. neoformans are sensitive to these antifungal compounds. Conclusions: In this study we observed that C. neoformans var. grubii (AFLP1 and AFLP1B) and C. neoformans var.neoformans (AFLP2) were the only cryptococcal varieties involved. All strains were found to be sensitive to the antifungals tested, results that are consistent with those found in the international literature (AU)

Antecedentes: La criptococosis es una infección fúngica de distribución mundial, causada principalmente porCryptococcus neoformans y Cryptococcus gattii. Objetivos: Determinar el tipo de apareamiento, los serotipos, los genotipos y la sensibilidad antifúngica de las cepas de C. neoformans provenientes de Lima Perú. Métodos: Se analizaron 32 cepas de Cryptococcus spp. del Instituto de Medicina Tropical de la Universidad Nacional Mayor de San Marcos de Lima, Perú. Veinticuatro cepas provenían de pacientes y 8 cepas fueron obtenidas de muestras ambientales. Resultados: Mediante la técnica de reacción en cadena de la polimerasa se determinó que 27 (84,4%) aislamientos eran C. neoformans var. grubii, serotipo A, con el tipo de apareamiento alfa. Asimismo, empleando la técnica AFLP, se determinó que 16 (50%) cepas de C. neoformans eran del genotipo AFLP1 y 13 (40,6%) del genotipo AFLP1B; además, 2 (6,3%) eran del genotipo AFLP2 (C. neoformans var.neoformans) y 1 (3,1%) resultó ser un híbrido entre ambas variedades (AFLP3). Los perfiles de sensibilidad antifúngica para anfotericina B, fluconazol y voriconazol mostraron que las 32 cepas de C. neoformans eran sensibles al panel de antifúngicos. Conclusiones: En el presente estudio observamos que C. neoformans var. grubii (AFLP1 y AFLP1B) y C. neoformansvar. neoformans (AFLP2) fueron las variedades encontradas. Además, todas las cepas resultaron sensibles al panel de antifúngicos, en concordancia con la literatura internacional (AU)

Molecular characterization and antifungal susceptibility of Cryptococcus neoformans strains collected from a single institution in Lima, Peru.

BACKGROUND: Cryptococcosis is a fungal infection with a worldwide distribution, mainly caused by Cryptococcus neoformans and Cryptococcus gattii. AIMS: To molecularly characterize the mating-types, serotypes, genotypes and antifungal susceptibility profiles of a set of retrospectively isolated C. neoformans strains from Lima, Peru. METHODS: A set of 32 Cryptococcus spp. strains from the Institute of Tropical Medicine of the National University of San Marcos, Lima, Peru, were included in this retrospective study. Twenty-four strains were isolated from patients, while the remaining 8 were isolated from the environment. RESULTS: Using conventional PCR, 27 (84.4%) of the isolates were identified as C. neoformans var. grubii mating-type alpha and serotype A. Using the AFLP fingerprinting, it was shown that 16 (50%) of the C. neoformans strains were genotype AFLP1, 13 (40.6%) were genotype AFLP1B, 2 (6.3%) were genotype AFLP2, and 1 (3.1%) was found to be a hybrid between both C. neoformans varieties (genotype AFLP3). The antifungal susceptibility profiles for amphotericin B, fluconazole and voriconazole showed that all the 32 C. neoformans are sensitive to these antifungal compounds. CONCLUSIONS: In this study we observed that C. neoformans var. grubii (AFLP1 and AFLP1B) and C. neoformans var. neoformans (AFLP2) were the only cryptococcal varieties involved. All strains were found to be sensitive to the antifungals tested, results that are consistent with those found in the international literature.

Streptococcus equi subsp. zooepidemicus meningitis in Peru.

A 59-year-old man with a history of fever, unsteadiness, hemiparesis, motor aphasia and consciousness disturbance was hospitalized for Streptococcus equi subsp. zooepidemicus meningitis. He denied contact with farm animals, but had a practice of consuming unpasteurized goats' cheese from an uncertain source.

Mangrove forest composition and structure in Las Perlas Archipelago, Pacific Panama

Mangrove forest is an important ecosystem that provides many services, but in Panama, as in other countries, they are under threat due to a variety of human activities. Nowadays, large areas of mangroves continue to be lost without been described and lack of management strategies. This study focused on the mangrove structure in the two largest islands, Isla del Rey and Isla San Jose, of Las Perlas Archipelago (LPA), Pacific Panama. Assessment of Landsat satellite imagery revealed loss of mangroves in the LPA of 965ha in the period 1974-1986, and 248ha in the period 1986-2000. The majority of the loss (>77%) from the two study islands was due to timber extraction and agricultural development. In May 2006, permanent plots following the CARICOMP protocol were established at two sites on Isla del Rey (R1 and R2) and one site on Isla San Jose (SJ) where standardized metrics such as species, height and diameter at breast height of adult trees and seedlings were recorded. Forest structure differed at the three sites, although R1 and R2 were most similar. At R1, Laguncularia racemosa was the important species and R2 was dominated by Pelliciera rhizophorae. Examination of the forest structure and classified imagery indicated that these sites are spatially dynamic and appear to be rejuvenating. The forest structure would indicate that the sites have been growth-limited previously by human activities and possibly by other factors. SJ was dominated by Rhizophora mangle and appears to have a mature forest with large adult trees and few seedlings. It does not appear to have shown the same extent of spatial regrowth as the other two sites between 1986 and 2000 and is relatively static. The establishment of permanent plots and monitoring will be useful as part of the management plan, as the LPA shows a variety of mangrove structures and could be subject to further coastal development. Rev. Biol. Trop. 58 (3): 857-869. Epub 2010 September 01.

Los bosques de manglar son ecosistemas importantes que proveen muchos servicios, pero éstos están bajo la amenaza de una variedad de actividades humanas y grandes áreas de manglar continúan perdiéndose en Panamá. Este estudio está enfocado en la estructura de manglar de las dos islas más grandes del Archipiélago de Las Perlas en el Pacifico Panameño (LPA), la Isla del Rey y la Isla San José. La evaluación de las imágenes del satélite Landsat revela la pérdida de manglares en LPA de 965ha en el periodo entre 1974-1986, y de 286ha en el periodo 1986-2000. La mayor parte de la pérdida (>77%) en las dos islas estudiadas fue debida a la extracción de madera y al desarrollo agrícola. En mayo de 2006, se establecieron parcelas permanentes siguiendo el protocolo de CARICOMP en dos sitios en la isla del Rey (R1 y R2) y un sitio en la Isla San José (SJ) donde especies, altura y diámetro a la altura de la copa de árboles adultos y jóvenes fueron registradas. La estructura del bosque difirió en los tres sitios, sin embargo R1 y R2 fueron los más similares. En R1, Laguncularia racemosa fue la especie más dominante y Pelliceria rhizophora en R2. El análisis de la estructura del bosque y de imágenes clasificadas indicó que estos sitios son espacialmente dinámicos y parecen estar regenerándose. La estructura del bosque indica que el crecimiento en los sitios ha estado limitado por las actividades humanas y posiblemente por otros factores. SJ fue dominado por Rhizophora mangle y parece tener un bosque maduro con árboles adultos grandes y pocos jóvenes. Éste sitio no parece mostrar la misma extensión de rebrote espacial de los otros dos sitios entre 1986-2000 y es relativamente estático. El establecimiento de parcelas permanentes y el monitoreo serán útiles en la implementación del plan de manejo, ya que los manglares del LPA tienen una variedad estructural y podrían estar sujetos a un mayor desarrollo costero.

Mangrove forest composition and structure in Las Perlas Archipelago, Pacific Panama.

Mangrove forest is an important ecosystem that provides many services, but in Panama, as in other countries, they are under threat due to a variety of human activities. Nowadays, large areas of mangroves continue to be lost without been described and lack of management strategies. This study focused on the mangrove structure in the two largest islands, Isla del Rey and Isla San Jose, of Las Perlas Archipelago (LPA), Pacific Panama. Assessment of Landsat satellite imagery revealed loss of mangroves in the LPA of 965ha in the period 1974-1986, and 248ha in the period 1986-2000. The majority of the loss (>77%) from the two study islands was due to timber extraction and agricultural development. In May 2006, permanent plots following the CARICOMP protocol were established at two sites on Isla del Rey (R1 and R2) and one site on Isla San Jose (SJ) where standardized metrics such as species, height and diameter at breast height of adult trees and seedlings were recorded. Forest structure differed at the three sites, although R1 and R2 were most similar. At R1, Laguncularia racemosa was the important species and R2 was dominated by Pelliciera rhizophorae. Examination of the forest structure and classified imagery indicated that these sites are spatially dynamic and appear to be rejuvenating. The forest structure would indicate that the sites have been growth-limited previously by human activities and possibly by other factors. SJ was dominated by Rhizophora mangle and appears to have a mature forest with large adult trees and few seedlings. It does not appear to have shown the same extent of spatial regrowth as the other two sites between 1986 and 2000 and is relatively static. The establishment of permanent plots and monitoring will be useful as part of the management plan, as the LPA shows a variety of mangrove structures and could be subject to further coastal development.

Hemoglobin variants, hematological parameters and beta-globin gene cluster haplotypes in an isolated Amerindian group from the Orinoco River Delta.

BACKGROUND: Several previous studies reported that the Venezuelan Warao Indians presented unusual genetic characteristics. AIM: The present study checked previous reports of a high frequency of hereditary persistence of fetal hemoglobin (HPFH) and examined other hematological traits. SUBJECTS AND METHODS: Standard hematology, electrophoresis on cellulose acetate, fetal hemoglobin alkali denaturation, gamma-globin chain, DNA amplification and sequencing, and denaturing gradient gel electrophoresis determinations were performed in 269 individuals living in two localities of the Orinoco River Delta. RESULTS: Two beta(s) genes, in apparently non-related individuals, were found. HPFH, detected in this same population of Warao Indians 25 years ago, was present in heterozygous form in five individuals from a large kindred, with hemoglobin F levels ranging from 3.7% to 8%, and with a pancellular distribution. The HPFH mutation was of the deletional type. beta-globin gene haplotypes were determined by direct counting (through family studies) in 150 chromosomes; 26% of the 150 examined cluster presented haplotype 2, 22% haplotype 6, and 13% a new, Warao haplotype. Haplotype 3, of probable African origin, was also found with a frequency of 5%. CONCLUSIONS: The presence of the HPFH mutation was confirmed, and the new beta-globin gene haplotype together with the presence of other rare variants indicates that the Warao are very distinctive in relation to other Native Americans. Evidence was also found of a slight admixture from Africa-derived subjects (Layrisse et al. 1988).

Rol epidemiológico de los agentes bacterianos y parasitarios en la enfermedad diarreica en niños menores de 5 años, Yarinacocha, Pucallpa / Epidemiology role of bacterian and parasitic agents in diarrhea diseases in children minors of the 5 years, Yarinacocha-Pucallpa

Con la finalidad de esclarecer el rol de los microorganismos en la emfermedad diarreica aguda en niños menores de 5 años, se diseñó un estudio de casos y controles. El estudio se realizó en la zona urbana de Yarinacocha, Pucallpa*Ucayali, entre agosto y noviembre de 1984. Fueron estudiados un total de 238 niños, 104 casos y 134 controles. En el 18.3 por ciento de los casos y en el 17.9 por ciento de los controles se aislaron bacterias; los gérmenes identificados fueron E. coli enteropatógena, Aeromona sobria, Aeromona caviae, Vibrio alginolitycus y Edwarsiella tarda. El estudio parasitológico fue positivo en el 63.2 por ciento de los casos examinados y en el 65.7 por ciento de los controles examinados. Se encontró poliparasitismo en el 48.7 por ciento de los niños. Los principales parásitos identificados fueron Ascaris lumbricoides, Giardia lamblia, Trichuris trichuria y Uncinarias. No se encontraron diferencias entre los casos y los controles. Se concluye que no se justifica el uso indiscriminado de antibióticos y antiparasitario en caso de enfermedad diarreica aguda de esta localidad y similares; así mismo se recomienda hacer una evaluación integral del niño antes de instalar su tratamiento antimicrobiano

Evaluación del Protocolo 86 para el tratamiento de las Leucemias Mieloblásticas Agudas (P 86 L.M.A.) / Evaluation of the Protocolo 86 for the treatment of Acute Mielogenous Leukemia (P 86 A.M.L)

Se presentan los resultados obtenidos en 56 pacientes con Leucemia Mieloblastica Aguda, menores de 60 años, Tratados con el Protocolo 86 (P 86 L.M.A.) en la Unidad de Hematología y Banco de Sangre del Hospital Universitario de Caracas, durante el período de 1986-1990. Veintitres pacientes (41%) obtuvieron remisión completa (RC) en un tiempo promedio de 50 días; veinte pacientes (36%) murieron por hemorragias e infecciones durante la pancitopenia post inducción y 13 (23%) no respondieron. La sobrevida libre de enfermedad para el 50%de los pacientes de 12 meses con sólo el 11%de los pacientes libres de enfermedad a los 33 meses. La sobrevida total de 21 meses para el 50%de los pacientes que alcanzaron remisión. Se analizan las posibles causas de estos resultados

Leucemia mieloide crónica: casuística del Hospital Universitario de Caracas / Chronic myeloid leukemia in the Hospital Universitario de Caracas

Se revisaron las historias clínicas de 83 pacientes con Leucemia Mieloide Crónica, cuyo diagnóstico y tratamiento se realizó en la Unidad de Hematología y Banco de Sangre del Hospital Universitario de Caracas durante el período 1966-1986. Del total, 51 eran del sexo masculino y 32 de sexo femenino. La sobrevida media a los 5 años fue de 50%. La evolución a crisis blástica se observo en el 56% de los casos. Se correlacionaron los hallazgos clínicos y hematológicos al momento del diagnóstico con la sobrevida con la finalidad de evaluar sus significados pronósticos. Se observaron sobrevidas más cortas en aquellos pacientes con mayor porcentaje de blastos en sangre periférica, menor número de plaquetas y mayor porcentaje de mielocitos. La investigación de Cromosomas Philadelfia no se realizó

Púrpuras / Purpura

En este artículo el autor nos dá una definición, clasificación y enfoque diagnóstico de las púrpuras y los agentes etiológicos que con frecuencia producen trombocitopenia. Muestra un cuadro clínico y el pronóstico que varía de acuerdo a la existencia y severidad de las complicaciones renales