137 research outputs found

    Densidad básica de la madera de Pseudotsuga menziesii (Mirb.) Franco en la Patagonia

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    In the Andean region of Patagonia, Argentina, in the provinces of Neuquén, Río Negro and Chubut, there are numerous Douglas Fir [Pseudotsuga menziesii (Mirb) Franco] plantations, which constitute one of the timber species most widely used in the region for commercial plantations. In this work, we studied Douglas Fir wood basic density and its variation within trees and among trees. Also, the relationship between wood density, ring-with and the proportion of latewood was examined by regression analysis, determining at the some time wood density of juvenile and mature wood. We found that mean wood density of Douglas Fir was 0,366 g/cm3, which is one of the lowest wood density values reported for this species elsewhere. Results show that rings-width and latewood proportion were significantly related to specific gravity. We also found that Douglas fir trees begun to produce mature wood at around 17 years of age.En la región andina de las provincias de Neuquén, Río Negro y Chubut de Argentina existen numerosas plantaciones de pino Oregón [Pseudotsuga menziesii (Mirb.) Franco], constituyendo una de las especies más utilizadas en plantaciones comerciales. En el presente trabajo se estudió la densidad básica de la madera de esta especie y su variación entre árboles y dentro de un mismo individuo, determinándose su relación con el ancho de anillos y la proporción leño temprano por medio de análisis de regresión. Paralelamente se determinó la densidad correspondiente a madera juvenil y madura. La densidad básica media para la población analizada fue de 0,366 g/cm3, valor que se encuentra entre los mínimos citados para diferentes lugares del mundo en los cuales se cultiva la especie. La densidad básica se correlacionó significativamente con el ancho de anillos y la proporción de madera tardía. Se encontró que la edad a partir de la cual se forma madera madura es 17 años

    Chronic Effects of a Wild Green Oat Extract Supplementation on Cognitive Performance in Older Adults: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial

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    Background and aim: Preliminary evaluation of a wild green oat extract (WGOE) (Neuravena® ELFA®955, Frutarom, Switzerland) revealed an acute cognitive benefit of supplementation. This study investigated whether regular daily WGOE supplementation would result in sustained cognitive improvements. Method: A 12-week randomised, double-blind, placebo-controlled cross-over trial of WGOE supplementation (1500 mg/day) versus placebo was undertaken in 37 healthy adults aged 67 ± 0.8 years (mean ± SEM). Cognitive assessments included the Stroop colour-word test, letter cancellation, the rule-shift task, a computerised multi-tasking test battery and the trail-making task. All assessments were conducted in Week 12 and repeated in Week 24 whilst subjects were fasted and at least 18 h after taking the last dose of supplement. Result: Chronic WGOE supplementation did not affect any measures of cognition. Conclusion: It appears that the cognitive benefit of acute WGOE supplementation does not persist with chronic treatment in older adults with normal cognition. It remains to be seen whether sustained effects of WGOE supplementation may be more evident in those with mild cognitive impairment

    Postoperative complications in patients undergoing thyroid surgery

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    Background and objectives: Postoperative complications from thyroid surgery are numerous and may be shown on different levels. Some of these complications may be detrimental for patients, so minimization of the risks should be always considered. We evaluated the postoperative complications in patients after surgery of the thyroid gland at the Clinic for Thoracic Surgery, Skopje. Material and method: In retrospective manner, all patients undergoing thyroid surgery during the one-year period (1. January- 31. December 2017) were evaluated. Patients were divided into two groups, whereas group ST included patients who underwent goiter removal and subtotal thyroidectomy while group TT included patients in who total thyroidectomy was done. In both groups we analyzed the demographic data and the occurrence of postoperative (in the first 48 hours) complications (stridor, hoarseness, hemorrhage, nerve dysfunction, tracheomalacia, hypocalcemia and the need for reintubation and tracheostomy). Results: Total data from 197 patients was evaluated. 120 patients had subtotal thyroidectomy while total thyroidectomy had 77 patients. Postoperative complications occurred in significantly larger number of patients in the TT group (64.9 vs. 40%). Hoarseness (8.4% vs. 18.5%), stridor (18.3% vs. 9.2%) tracheomalacia (5% vs. 1.2%) and hematoma (2.5% vs. 3.8%) occurred in respect to the groups. Hypocalcaemia occurred in significantly larger number of patients in TT group. Permanent nerve injury was found in one patient in the same group and tracheotomy was done only in one patient. Conclusion: Overall results from our study show that the complications after thyroid surgery occur in all patients who undergo thyroid surgery. However, more severe complications and outnumbered are complications in patients who undergo total thyroidectomy. Key words: complications, occurrence, thyroid surgery, total thyroidectomy

    Impaired Inhibitory Control in Recreational Cocaine Users

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    Chronic use of cocaine is associated with impairment in response inhibition but it is an open question whether and to which degree findings from chronic users generalize to the upcoming type of recreational users. This study compared the ability to inhibit and execute behavioral responses in adult recreational users and in a cocaine-free-matched sample controlled for age, race, gender distribution, level of intelligence, and alcohol consumption. Response inhibition and response execution were measured by a stop-signal paradigm. Results show that users and non users are comparable in terms of response execution but users need significantly more time to inhibit responses to stop-signals than non users. Interestingly, the magnitude of the inhibitory deficit was positively correlated with the individuals lifetime cocaine exposure suggesting that the magnitude of the impairment is proportional to the degree of cocaine consumed

    Reduced Spontaneous Eye Blink Rates in Recreational Cocaine Users: Evidence for Dopaminergic Hypoactivity

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    Chronic use of cocaine is associated with a reduced density of dopaminergic D2 receptors in the striatum, with negative consequences for cognitive control processes. Increasing evidence suggests that cognitive control is also affected in recreational cocaine consumers. This study aimed at linking these observations to dopaminergic malfunction by studying the spontaneous eyeblink rate (EBR), a marker of striatal dopaminergic functioning, in adult recreational users and a cocaine-free sample that was matched on age, race, gender, and personality traits. Correlation analyses show that EBR is significantly reduced in recreational users compared to cocaine-free controls, suggesting that cocaine use induces hypoactivity in the subcortical dopamine system

    Minerals from Macedonia XI. Silicate varieties and their localities - Identification by FT IR Spectroscopy

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    Among the rich orc deposits present in Macedonia, the silicate minerals arc thc most numerous group. The great majority of these minerals appear as rathcr large and well formed single crystal aggregates in the nature. Sometimes, however, some of the mineral species appear in association with other minerals whose crystals are not well developed. Here an overview of the basic morphological, physico-chemical and crystallographic characteristics of the most typical silicates collected from various localities within the Republic of Macedonia is given. The mineralogical and petrological features of the localities where the specimens are collected from are presented as well. Also an attempt to identify the minerals using the Ff IR spectroscopy and to classify them according to their structural characteristics is performed. The identification of the minerals was based on the comparison of the infrared spectra of our specimens with the corresponding literature data for the mineral species originating all over the world. The coloured pictures of all studied silicate minerals are presented as well
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