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

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

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

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

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

Impaired Inhibitory Control in Recreational Cocaine Users

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

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

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 mínimas citadas para diferentes lugares del mundo en las cuales se cultiva la especie. La densidad básica se correlacionó significativamente con el ancho de anillas y la proporción de madera tardía. Se encontró que la edad a partir de la cual se forma madera madura es 17 años

Minerals from Macedonia. X. Separation and identification of some oxide minerals by FT IR spectroscopy, AAS, AES-ICP and powder XRD

The fourier transform infrared spectroscopy (FT IR), powder X–ray diffraction (XRD) as well as atomic absorption spectrometry (AAS) and emission atomic spectrometry with induced coupled plasma (AES-ICP) are used as powerful techniques in the process of identification of several oxide minerals (hematite, Fe 2 O 3; magnetite, Fe 3 O 4; limonite, FeOOH; goethite, α-FeOOH; corundum, Al 2 O 3; rutile, TiO 2; chromite, FeCr2O4 collected from various localities in the Republic of Macedonia. The mineral association of the localities where the minerals appear from (Pehčevo, Damjan, Alšar, Ržanovo, Sivec, Raduša, Veselčani, Košino) with their petrological and mineralogical aspects are discussed. The content of the main and trace elements in the studied oxides is determined using AAS, AES-ICP, classical chemical analysis and the results are related to the geological and mineralogical conditions of their origin localities. As a pattern for mineral identification was the comparison of their infrared bands (their number, frequencies and intensities) with the corresponding literature data for the analogue (natural and synthetic) mineral species. In this context, in some cases disagreements between the infrared spectra of the studied mineral types (the number of bands and their frequencies) and the corresponding literature analogues appeared and have been discussed. The caused additional difficulties in the identification of the studied minerals were solved by the analysis of their X-ray patterns. Powder X-ray patterns were also representative for the detection of impurities in some of the studied mineral samples