Forestry-Based Livelihoods in Central Vietnam: An Examination of the \u3cem\u3eAcacia\u3c/em\u3e Commodity Chain: A Case from Thua Thien Hue Province, Vietnam

Forestry-based livelihoods in remote Vietnamese communities have been influenced in recent years by forest land allocation schemes, changes to property rights, and forest management devolution initiatives. Examples include the Five Million Hectare Reforestation Program, Project 327, and official “Red Books” that grant long-term land use rights and access rights to villagers. Major challenges to forestry-based livelihoods include disputes over land tenure, conflict between different levels of government, illegal logging practices and harvesting of NTFPs and competition over land for natural versus plantation forests. As a result, forest degradation and rural poverty continue to be debilitating obstacles to development in Central Vietnam that must be addressed if sustainable livelihoods are achieved. Forestry-based livelihoods are one of many strategies being promoted by the Vietnamese government to combat environmental degradation and rural poverty. The goal of this research is to investigate why Acacia trees are being grown by upland villagers in Central Vietnam, what benefits and challenges are associated with growing tree crops, and how land tenure and access rights can be strengthened to improve the livelihoods of rural villagers. I explore these issues by utilizing a commodity chain framework to examine the increasingly widespread planting of Acacia, a tree crop to which many villagers are turning as a primary source of income. A timber commodity chain is used to examine how timber is extracted from villages, transported and processed at sawmills, then brought to urban centres to be sold as finished products. The commodity chain analysis is used to analyze the processes and cossts associated with planting the tree crop and the market opportunities derived from the crop at different stages in the commodity chain. Primary data collection methods include a villager livelihood questionnaire conducted with 58 hourseholds in mid-2008; 34 additional key informant semi-structured interviews with middlemen, processors, retailers, government officials, and other stakeholders invoolved in Acacia cultivation; participant observation; and other visually-based participatory research methods such as transect walks. Results from the study prove that within Central Vietnam most rural upland villagers do not have secure land tenure, yet they grow Acacia trees as part of their long-term livelihood strategies for a variety of benefits, apart from earning income. These benefits include maintaining soil integrity, using tree logs as building materials, and harvesting NTFPs. Furthermore, the flow of Acacia products through the commodity chain is unregulated and subject to erratic price fluctuations. Nevertheless, Acacia cultivation is enticing to rural villagers and many are willing to cease growing staple foods and devote their lands to commercial forestry because of the potential profits and additional benefits listed above that the Acacia tree crops provide. The study highlights the importance of forestry resources to rural upland villagers within the last two decades and outlines the processes and challenges that occur at each stage in the Acacia commodity chain

Nitrogen-Doped Carbonaceous Materials for Removal of Phenol from Aqueous Solutions

Carbonaceous material (brown coal) modified by pyrolysis, activation, and enrichment in nitrogen, with two different factor reagents, have been used as adsorbent of phenol from liquid phase. Changes in the phenol content in the test solutions were monitored after subsequent intervals of adsorption with selected adsorbents prepared from organic materials. Significant effect of nitrogen present in the adsorbent material on its adsorption capacity was noted. Sorption capacity of these selected materials was found to depend on the time of use, their surface area, and pore distribution. A conformation to the most well-known adsorption isotherm models, Langmuir, and Freundlich ones, confirms the formation of mono- and heterolayer solute (phenol) coverage on the surface of the adsorbent applied herein. The materials proposed as adsorbents of the aqueous solution contaminants were proved effective, which means that the waste materials considered are promising activated carbon precursors for liquid phase adsorbents for the environmental protection

Calculation of perturbation factors for the PTW 23343 Markus ionization chamber in proton beams

In this work, perturbation factors for the PTW 23343 Markus ionization chamber in proton beams were determined using Monte Carlo simulations based on the MCNPX code in version of 2.7.0. The calculations were performed for chosen proton energies from 15 MeV to 80 MeV and for various energy spread. The main conclusion is that the perturbation factors for the considered ionization chamber cannot be neglected in the region with the disturbed proton equilibrium in the above-mentioned energy range

Determination of energy spectra in water for 6 MV X rays from a medical linac

There is a lack of extensive data comprising energy spectra in water for beams generated by medical accelerators applied in radiotherapy. The purpose of this work was the determination of energy spectra in water for the 6 MV X-ray therapeutic beam from the medical linac — Clinac 2300 by Varian. The spectra were derived with the use of Monte Carlo computer simulations basing on MCNPX code in version of 2.7.0. The performed investigations indicate that shapes of the spectra as well as the mean Energy of the considered beams depend on a depth in water, a distance from the central-axis of the beam and a radiation field size. The obtained results are valuable for constructors of medical linacs and, additionally, they can be applied in advanced treatment planning systems. Therefore, all obtained spectra in a numerical form are available for common use. They will be sent to users after forwarding e-mail message to the authors of this paper

Purpose in Life and Conscientiousness Protect Against the Development of Suicidal Ideation in U.S. Military Veterans With PTSD and MDD: Results From the National Health and Resilience in Veterans Study.

Background:Although several studies have examined risk factors for suicidal ideation among veterans, little is known about risk and protective factors for suicidal ideation in high-risk veteran samples. Thus, this study examined a broad range of risk and protective factors associated with the development of suicidal ideation in a high-risk sample of U.S. veterans who screened positive for current posttraumatic stress disorder (PTSD) and/or major depressive disorder (MDD). Methods:Data were analyzed from the National Health and Resilience in Veterans Study, a nationally representative, prospective cohort study of U.S. veterans. Veterans completed self-report measures to screen for PTSD and MDD and to assess for risk and protective factors. The sample included 222 veterans with PTSD and/or MDD who did not endorse suicidal ideation at baseline and completed at least one assessment over a seven-year follow-up period. A multivariable binary logistic regression analysis was conducted to examine baseline factors associated with incident suicidal ideation. Results:Nearly one in three (27.1%) of veterans with PTSD and/or MDD developed suicidal ideation over the seven-year follow-up period. Non-Caucasian race and lower scores on measures of purpose in life, conscientiousness, and frequency of religious service attendance were independently associated with incident suicidal ideation. Lower purpose in life (52.3%) and conscientiousness (33.2%) explained the vast majority of variance in incident suicidal ideation. Conclusion:Nearly 30% of veterans with PTSD and/or MDD who did not endorse suicidal ideation at baseline developed suicidal ideation over a seven-year period. Prevention and treatment efforts designed to bolster purpose in life and conscientiousness may help mitigate risk for suicidal ideation in this high-risk population

Modelowanie terapeutycznych wiązek promieniowania za pomocą metody Monte Carlo

In this work models of two therapeutic beams of high-energy X-rays and protons were elaborated. The purpose of the investigation was the determination of significant parameters used in clinical dosimetry, basing on the elaborated models. The calculations were performed by means of computer simulations on the ground of the Monte Carlo algorithm. At the first stage of this work the head model of the Clinac 2300 linear accelerator by Varian was elaborated with the use of the professional MCNPX code. Verification of this model was carried out using the comparison between the calculated and measured depth-dose distributions in the standard dosimetry medium – water. The depth-dose distributions in water were determined for SSD = 100 cm and for three square radiation fields of 3 cm x 3 cm, 10 cm x 10 cm and 40 cm x 40 cm. Successful validation of the prepared model with the measuring system model made it possible to begin the next part of this investigation in which the energy spectra along the central axis of the beam and in the direction perpendicular to this axis in water were calculated. The spectral calculations were performed for the therapeutic 20 MV X-ray beam. The influence of the radiation field sizes on the shapes of the spectra in water were determined and the mean energy of the beam was calculated for the chosen irradiation conditions. At the second stage of this work the proton beams and the PTW 23343 Markus type ionization chamber used in clinical dosimetry were modeled. On the base of these models the perturbation factors , and the total perturbation factor were calculated for the punctual proton beam with energies of 15 MeV, 30 MeV, 60 MeV, 80 MeV. The influence of energy and spatial spread on the perturbation factors was determined. Moreover, the model of the real beam based on the passive system forming the proton beam in the Institute of Nuclear Physics of Polish Academy of Sciences in Bronowice was elaborated. The investigation basing on this model indicated that the depth-dose distributions obtained with the use of the water logic detectors and with the Marcus chamber model are compatible and they agree with the experimental results

Cognitive impairment and decline in cognitively normal older adults with high amyloid-β: A meta-analysis

AbstractIntroductionThis meta-analysis aimed to characterize the nature and magnitude of amyloid (Aβ)-related cognitive impairment and decline in cognitively normal (CN) older individuals.MethodMEDLINE Ovid was searched from 2012 to June 2016 for studies reporting relationships between cerebrospinal fluid or positron emission tomography (PET) Aβ levels and cognitive impairment (cross-sectional) and decline (longitudinal) in CN older adults. Neuropsychological data were classified into domains of episodic memory, executive function, working memory, processing speed, visuospatial function, semantic memory, and global cognition. Type of Aβ measure, how Aβ burden was analyzed, inclusion of control variables, and clinical criteria used to exclude participants, were considered as moderators. Random-effects models were used for analyses with effect sizes expressed as Cohen's d.ResultsA total of 38 studies met inclusion criteria contributing 30 cross-sectional (N = 5005) and 14 longitudinal (N = 2584) samples. Aβ-related cognitive impairment was observed for global cognition (d = 0.32), visuospatial function (d = 0.25), processing speed (d = 0.18), episodic memory, and executive function (both d's = 0.15), with decline observed for global cognition (d = 0.30), semantic memory (d = 0.28), visuospatial function (d = 0.25), and episodic memory (d = 0.24). Aβ-related impairment was moderated by age, amyloid measure, type of analysis, and inclusion of control variables and decline moderated by amyloid measure, type of analysis, inclusion of control variables, and exclusion criteria used.DiscussionCN older adults with high Aβ show a small general cognitive impairment and small to moderate decline in episodic memory, visuospatial function, semantic memory, and global cognition

Metals Ions Removal by Polymer Membranes of Different Porosity

The effect of the amount of pore generating agent (polyvinylpyrrolidone) added to standard polymer membranes containing 18 wt.% of polyethersulfone on the physicochemical properties of the membranes and their capacity for removal of iron and copper ions from the liquid phase was studied. The membranes were obtained by the phase inversion method. The results have shown that the modification of polymer membranes by the use of different amounts of the pore forming agent in their syntheses leads to significant changes in porosity and has beneficial effect on equilibrium water content. The membranes studied were found to show different acid-base surface character, but for all membranes studied, a significant dominance of oxygen groups of acidic character was evidenced. The most effective were the membranes of the lowest content of polyvinylpyrrolidone, while the lowest values of resistance showed the membranes of the highest content of PVP, and so the ones of the greatest porosity