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1.
Bioscience ; 67(6): 546-557, 2017 Jun 01.
Article in English | MEDLINE | ID: mdl-28584342

ABSTRACT

The scale and magnitude of complex and pressing environmental issues lend urgency to the need for integrative and reproducible analysis and synthesis, facilitated by data-intensive research approaches. However, the recent pace of technological change has been such that appropriate skills to accomplish data-intensive research are lacking among environmental scientists, who more than ever need greater access to training and mentorship in computational skills. Here, we provide a roadmap for raising data competencies of current and next-generation environmental researchers by describing the concepts and skills needed for effectively engaging with the heterogeneous, distributed, and rapidly growing volumes of available data. We articulate five key skills: (1) data management and processing, (2) analysis, (3) software skills for science, (4) visualization, and (5) communication methods for collaboration and dissemination. We provide an overview of the current suite of training initiatives available to environmental scientists and models for closing the skill-transfer gap.

2.
Invest Clin ; 48(3): 287-94, 2007 Sep.
Article in Spanish | MEDLINE | ID: mdl-17853788

ABSTRACT

The prostate is a gland that surrounds the posterior urethra in man and, along with seminal vesicles, produces prostatic and seminal fluids. Prostatitis, benign prostatic hyperplasia (BPH), and prostate cancer are the most frequent pathologies of this gland. Zinc is an important element in the makeup of prostatic fluid and plays an important role in the immunology of the infectious and neoplastic pathologies of the prostate. The aim of this study was to determine zinc concentrations in prostatic fluid of patients with prostate pathologies and to use this measurement as a diagnostic parameter. Thirty patients with prostatic pathologies and ten healthy controls were studied. Prostatic fluid samples were collected using prostatic massage. Zinc concentration was determined using electrothermal atomizeratomic absorption spectrometry (ETA-AAS). The mean zinc concentrations obtained in the studied population were as follows: 11 patients with BPH: 15.087,78 micromol/dL, 10 patients with prostatis: 863,33 micromol/dL, 9 patients with prostate cancer: 1.027,60 micromol/dL and 10 healthy subjects: 7.467,52 micromol/dL. The low zinc concentrations obtained in patients with prostatitis and prostate cancer, in contrast to the control group, led us to consider the possibility of recommending zinc supplements as a coadjuvant therapy in patients with prostatitis and also, to use zinc measurements as another diagnostic tool, for cases in which it is necessary to differentiate benign prostatic hyperplasia from prostate cancer.


Subject(s)
Adenocarcinoma/metabolism , Body Fluids/chemistry , Prostate/chemistry , Prostatic Hyperplasia/metabolism , Prostatic Neoplasms/metabolism , Prostatitis/metabolism , Zinc/analysis , Adult , Aged , Biomarkers , Humans , Male , Middle Aged , Prospective Studies , Zinc/deficiency , Zinc/physiology
3.
Invest Clin ; 47(4): 349-59, 2006 Dec.
Article in Spanish | MEDLINE | ID: mdl-17176903

ABSTRACT

The importance of Zinc (Zn) as a necessary oligoclement for human nutrition begins in the first three decades of life. At the moment, the role that Zn plays in the infantile nutrition is very well-known, acquiring a special connotation in children with proteic-energetics malnutrition (PEM). In this study the daily ingestion and the serum measuremets of Zn were determined in 64 undernourished children (light, mild and severe) and in 25 eutrophic children with ages between 1 to 5 years, belonging to families of the strata IV and V according to the Graffar scale corrected by age. The results of the serum values of Zn were for the light undernourished of 39.73 +/- 14.97 microg/dL (30.38 microg/dL-44.56 microg/dL), for the mild undernourished of 35.07 +/- 28.13 microg/dL (27.76 microg/dL-65.80 microg/dL) and for the severe undernourished of 15.48 +/- 10.44 microg/dL (5.57 microg/dL-28.56 microg/dL), which were diminished in relation with the control group, 76.71 +/- 33.29 microg/dL (45.75 microg/dL - 78.27 microg/dL) with p < 0.0001. Equally, there were significant differences (p < 0.001) among the group of severe undernourished with the light undernourished and normal subjects. In relation with the daily ingestion of Zn, a statistically significant difference was observed only (p < 0.001) in the severe undernourished, 1.87 +/- 0.54 mg/día (1.20 mg/día-2.87 mg/día) when comparing them with the light undernourished, 5.48 +/- 0.98 mg/día (3.50 mg/día-7.87 mg/día), the mild undernourished, 4.99 +/- 1.24 mg/día (4.10 mg/día-11.42 mg/día) ) and the normal subjects, 6.22 +/- 0.98 mg/día (4.8 mg/día-8.02 mg/día). There was a positive correlation between ingestion and seric values of Zn when the 3 undernourished groups were studied. These results allow to conclude that both the seric values of Zn and its ingestion show modifications in relation with the degree of nutritional deficiency.


Subject(s)
Protein-Energy Malnutrition/blood , Zinc/blood , Analysis of Variance , Child, Preschool , Female , Humans , Infant , Male , Prospective Studies , Spectrophotometry, Atomic , Venezuela , Zinc/deficiency
4.
Invest. clín ; 47(4): 349-359, dic. 2006. tab
Article in Spanish | LILACS | ID: lil-462849

ABSTRACT

La importancia del zinc (Zn) como oligoelemento necesario para la nutrición humana data de más de tres décadas. Actualmente el papel que desempeña el Zn en la nutrición infantil es bien conocido, adquiriendo especial connotación en los niños con desnutrición proteico-energética (DPE). En el presente estudio se determinaron las ingestas diarias y las concentraciones séricas de Zn en 64 niños desnutridos (leves, moderados y graves) y en 25 niños eutróficos en edades comprendidas entre 1 y 5 años, pertenecientes a familias de los estratos IV y V según Graffar modificado. Los resultados de las concentraciones séricas de Zn fueron en los desnutridos leves en 39,73 ± 14,97µg/dL (30,38 µg/dL-44.56 µg/dL), en los desnutridos moderados 35,07 ± 28,13 µg/dL (27,76 µg/dL-65,80 µg/dL) y en los desnutridos graves 15,48 ± 10,44 µg/dL (5,57 µg/dL-28,56 µg/dL), valores que estuvieron disminuidos en relación con el grupo control, 76,71 ± 33,29 µg/dL (45,75 µg/dL-78,27 µg/dL) con p < 0,0001. Igualmente se encontraron diferencias significativas (p < 0,001) entre el grupo de desnutridos graves y los desnutridos leves y moderados. En relación con la ingesta diaria de Zn sólo se observó diferencia estadísticamente significativa (p < 0,001) en los desnutridos graves, 1,87 ± 0,54 mg/día (1,20 mg/día-2,87 mg/día) al compararlos con los desnutridos leves, 5,48 ± 0,98 mg/día (3,50 mg/día-7,87 mg/día), los desnutridos moderados, 4,99 ±1,24 mg/día (4,10 mg/día-11,42 mg/día) y los eutróficos, 6,22 ± 0,98 mg/día (4,8 mg/día-8,02 mg/día). Se encontró una correlación positiva (r = 0,5146; p < 00,1) entre ingesta y concentración sérica de Zn cuando se estudiaron los 3 grupos de desnutridos. Estos resultados permiten concluir que tanto las concentraciones séricas de Zn como la ingesta se ven modificadas en relación con el grado de déficit nutricional


Subject(s)
Humans , Male , Female , Protein-Energy Malnutrition , Zinc , Nutritional Physiological Phenomena , Medicine , Venezuela
5.
Invest Clin ; 44(1): 51-60, 2003 Mar.
Article in Spanish | MEDLINE | ID: mdl-12703183

ABSTRACT

Alterations of plasma levels of zinc and in the immune system in Down's syndrome (DS) have been reported. These alterations have been associated with a high rate of infectious diseases, which represent the main cause of mortality in affected individuals. The objectives of this study were to determine plasma zinc levels and to evaluate the immune system in DS patients. Peripheral blood samples were obtained from 43 DS patients examined at the Unidad de Genética Médica, Universidad del Zulia in Maracaibo, Venezuela. Their mean age (+/- SD) was 2.3 +/- 2.0 years. As control group, 40 healthy children were studied (mean +/- SD 2.3 +/- 2.0 years). Karyotypes by a standard technique, the determination of plasma levels of zinc by atomic absorption spectrophotometry and the evaluation of the immune system by flow cytometry were carried out in the study groups. All DS patients had free trisomy 21. Significantly disminished zinc plasma levels, helper T lymphocyte (CD4) percentage, helper/cytotoxic (CD4/CD8) ratio and B-cells (CD19) were found in DS patients by matching with control group. An increase in CD8 was also found. No significative difference in the lymphocyte subpopulations between DS patients with disminished plasma levels of zinc and DS patients with normal zinc were found. These findings suggest that zinc deficiency is not the sole etiology involved in the disorders of immune system seen in DS patients. Other factors, such as thymic alterations and molecular abnormalities due to gene overexpression of loci located on chromosome 21 could be involved. Although, zinc supplementation is recommended in these patients with zinc deficiency, further studies with a double-blind, placebo versus zinc design are needed to evaluate the potentially beneficial effects of zinc treatment in DS patients.


Subject(s)
Down Syndrome/blood , Lymphocytes/blood , Zinc/blood , Child , Child, Preschool , Down Syndrome/immunology , Female , Flow Cytometry , Humans , Immune System/immunology , Infant , Infant, Newborn , Lymphocyte Count , Lymphocytes/cytology , Male , Spectrophotometry, Atomic , Zinc/deficiency
6.
Invest. clín ; 44(1): 51-60, mar. 2003. tab
Article in Spanish | LILACS | ID: lil-402028

ABSTRACT

Se ha reportado alteración de los niveles plasmáticos de cinc y trastornos del sistema inmunitario en los pacientes con síndrome de Down (SD), lo que se ha asociado con alta tasa de enfermedades infecciosas, las cuales representan una de las principales causas de mortalidad en los individuos afectados. El objetivo de este trabajo fue determinar las concentraciones plasmáticas de cinc y evaluar el sistema inmunitario en pacientes con SD. Para esto se tomaron muestras de sangre periférica de 43 pacientes con SD con promedio de edad ± DE, de 2,3 ± 2 años; que asistieron a la Unidad de Genética Medica de la Universidad del Zulia en Maracaibo, Venezuela. Como controles se estudiaron 40 niños aparentemente sanos con promedio de edad de 2,5 ± 2,2 años. A todos los pacientes se les realizó el cariotipo según la técnica convencional, determinación de cinc por espectrofotometría de absorción atómica y citometría de flujo para evaluar el sistema inmunitario. Todos los pacientes presentaban trisomía libre del cromosoma 21. Se observó una disminución significativa de los niveles de cinc; del porcentaje de linfocitos T cooperadores (CD4), de la relación entre éstos y los linfocitos T citotóxicos (CD4/CD8) así como también, del porcentaje de células B (CD19) al compararlos con los controles. También se observó un aumento en CD8. Al comprar las subpoblaciones linfocitarias en los pacientes con SD que presentaron valores normales de cinc con aquellos que tenían valores disminuidos no se encontró diferencia estadísticamente significativa. Los resultados obtenidos en esta investigación sugieren que probablemente no sólo la deficiencia de cinc está involucrada en las alteraciones del sistema inmunitario observada en los pacientes con SD; otros factores previamente descritos, tales como las alteraciones tímicas y las anormalidades moleculares debidas a la sobreexpresión de genes localizados en el cromosoma 21, podrían estar involucrados. Aunque se recomienda la suplementación de cinc en estos pacientes con deficiencia de este oligoelemento , se necesitan estudios con diseño a doble ciego de placevo versus cinc para evaluar los potenciales efectos beneficiosos del tratamiento con cinc en pacientes con SD


Subject(s)
Humans , Male , Female , Down Syndrome , Lymphocyte Subsets , Patients , Zinc , Medicine , Venezuela
7.
Acta odontol. venez ; 40(2): 52-57, ago. 2002. tab
Article in Spanish | LILACS | ID: lil-353173

ABSTRACT

En este estudio se establecieron los niveles de mercurio (Hg) en cabello de individuos profesionalmente expuestos en el área odontológica y se contrastaron con las concentraciones mercuriales de un grupo control no expuesto ocupacionalmente al Hg. Las muestras de cabello fueron recolectadas de 15 individuos expuestos y 15 no expuestos, residentes de la ciudad de Maracaibo y zonas circunvencians. Los individuos fueron interrogados a través de una encuesta en relación a datos personales, dirección de habitación, ocupación, alimentación, hábitos, salud, tratamiento médicos, número de restauraciones de amalgama, tratamientos cosméticos en el cabello, etc. Se tomaron 2 cm de cabello distal en la zona occipital del cuero cabelludo de cada individuos, las cuales se almacenaron en bolsas plásticas de cierre hermético a 4§C. Previo al análisis espectrométrico, las muestras se levaron y se desmineralizaron usando microondas. La determinacion exacta, precisa y libre de interferencias de Hg se realizó empleando la espectrometría de absorción atómica por vapor frío. La concentración media de Hg (+- 1 DE obtenida para el grupo expuesto (E) fue 2,07 +- 2,23 (ca. intervalo experimental: 0,13 - 7,91 mg Hg/g) y para el grupo control (C) fue 2,65 +- 2,06 (ca. intervalo experimental): 0,75 - 6,75 mg Hg/g). No se observaron diferencias estadísticamente significativas (p>0,05) entre los niveles de mercurio para los grupos E y C; por lo tanto, el vapor de Hg absorbido en la clínica dental no influyó en el nivel de Hg en cabello del grupo expuesto, debido posiblemente al uso de sistemas de aire acondicionado y buena ventilación que presentaron las clínicas. Los resultados obtenidos en este estudio revelaron que el manejo y uso apropiado de la amalgama dental no altera el nivel de mercurio presente en el cabello del personal que labora en la clínica dental


Subject(s)
Humans , Adolescent , Adult , Female , Middle Aged , Dental Amalgam , Dental Staff , Occupational Exposure/statistics & numerical data , Hair , Mercury , Dental Clinics/standards , Data Collection , Dental Equipment , Spectrophotometry, Atomic/methods , Nutrition Surveys , Occupational Diseases , Dental Restoration, Permanent/statistics & numerical data , Data Interpretation, Statistical , Venezuela , Ventilation/methods
8.
Oecologia ; 96(2): 179-185, 1993 Nov.
Article in English | MEDLINE | ID: mdl-28313413

ABSTRACT

Introduced African grasses are invading Neotropical savannas and displacing the native herbaceous community. This work, which is part of a program to understand the success of the African grasses, specifically investigates whether introduced and native grasses differ in their water relations. The water relations of the native Trachypogon plumosus and the successful invader Hyparrhenia rufa were studied in the field during two consecutive years in the seasonal savannas of Venezuela. The two C4 grasses differed clearly in their responses to water stress. H. rufa consistently had higher stomatal conductance, transpiration rate, leaf water and osmotic potential and osmotic adjustment than the native T. plumosus. Also, leaf senescence occurred much earlier during the dry season in H. rufa. Both grasses showed a combination of water stress evasion and tolerance mechanisms such as stomatal sensitivity to atmospheric or soil water stress, decreased transpiring area and osmotic adjustment. Evasion mechanisms are more conspicuous in H. rufa whereas T. plumosus is more drought tolerant and uses water more "conservatively". The evasion mechanisms and oportunistic use of water by H. rufa, characteristic of invading species, contribute to, but only partially explain, the success of this grass in the Neotropical savannas where it displaces native plants from sites with better water and nutrient status. Conversely, the higher water stress tolerance of t. plumosus is consistent with its capacity to resist invasion by alien grasses on shallow soils and sites with poorer nutrient and water status.

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