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There is a strong link between vegetation and environmental factors. Therefore, to elucidate how the stoichiometric characteristics of plants respond to different habitats, we studied organic carbon (C) and total nitrogen (N) stoichiometry characteristics of plants in four different habitats of two different natural Korean pine forests. Three of the habitats (gaps, mounds, and pits) were formed via tree uprooting, whereas an undisturbed site (closed canopies) was used as a control. The followings were our main findings: (1) the organic carbon content of more than half of the 12 picked plants showed significant differences in different habitats. Most of the plants in pit-mound complexes exhibited lower organic carbon contents than plants in gaps and closed canopies; (2) there was no significant differences in the total nitrogen content in 13 of the 25 groups of plant samples; (3) interestingly, the C/N of the sample groups with significant differences in total nitrogen also showed significant differences; (4) there was no significant variations in the stoichiometric characteristics of plants that grew in gaps; however, the variations among plants that grew in pits and mounds were significant; (5) through redundancy analysis (RDA), we find that the main factors effecting the C and N stoichiometric characters of the plants were plants own regulation and the change of photosynthetically active radiation (PAR). In conclusion, the C and N stoichiometric characteristics of plants did not respond to gap formations, but they did strongly respond to pit-mound complex formations. Photosynthetically active radiation was the most important effective factor to plants in the four habitats. [ABSTRACT FROM AUTHOR]

An emerging HIV epidemic can be seen among men who have sex with men (MSM) in Vietnam. There are currently no evidence-based behavioral sexual risk reduction interventions for MSM in this setting. Between October 2012 and June 2013, 100 high-risk MSM from Ho Chi Minh City were enrolled in an open pilot trial to assess feasibility and acceptability of a group-based, manualized sexual risk reduction intervention, and to preliminarily examine changes in primary and secondary outcomes. Participants completed a behavioral assessment battery and HIV testing at baseline, 3, and 6 months post-baseline. Over 80.0 % of the sample was <25 years old and 77.0 % identified as Bong kin ("hidden," masculine-appearing). Feasibility and acceptability of the program was evidenced by 87.0 % retention for the intervention sessions, 78.0 % completion of the 6 month assessment, and positive responses on evaluation forms and qualitative exit interviews. There was a decline in the number of condomless anal sex acts from baseline (6.32) to 3 month (2.06) and 6 month (2.49) follow-up (p < .0001). These data support the need for further testing of this group-based, behavioral HIV prevention intervention to reduce sexual risk behavior among MSM in Vietnam in a randomized controlled efficacy trial. [ABSTRACT FROM AUTHOR]

MDPE- g-MAH copolymers were prepared with MDPE (medium density polyethylene) and MAH (maleic anhydride) under different irradiation doses of high-energy electron accelerator, and FTIR spectra confirmed their structure. The effect of the different contents of MDPE- g-MAH copolymers on properties of MDPE/CaCO system is studied intensively. By adding 4 Phr (parts per hundred of resin) MDPE- g-MAH in MDPE/CaCO system under irradiation dose of 0.7 MGy, the tensile strength increases from 16.3 MPa to 19.9 MPa, and elongation at break increases from 437% to 518%. SEM images show the domain size of CaCO in MDPE- g-MAH systems becomes small. Definitely, MDPE- g-MAH copolymer could improve the compatibility of MDPE/CaCO system effectively. [ABSTRACT FROM AUTHOR]

In order to determine how a roadway withstands a momentum wave and determine the extent of damage to rock surrounding the roadway under different force wave peak impacts, the roadway dynamic response state was analysed using numerical simulation method. The roadway’s critical peak force wave and fracture region under dynamic wave action were put forward. It is concluded that the method has practical value to roadway support and rockburst prevention. [ABSTRACT FROM AUTHOR]

Stress distribution rules and deformation and failure properties of coal and rock bodies influenced by mining were analyzed. Experimental research on permeability of coal and rock samples under different loading conditions was finished in the laboratory. In-situ measurement of coal permeability influenced by actual mining was done as well. Theory analysis show that permeability varied with damage development of coal and rock under stress, and the influence of fissure on permeability was greatest. Laboratory results show that under different loading conditions permeability was different and it varied with stress, which indicated that permeability was directly related to the loading process. In-situ tests showed that permeability is related to abutment stress to some degree. The above results may be referenced to gas prevention and drainage. [ABSTRACT FROM AUTHOR]