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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]

The article discusses the result of a behavioral and psychosocial survey undertaken in Ho Chi Minh City, Vietnam which revealed the association between engagement with peer health educators and willingness to use pre-exposure prophylaxis (PrEP) among male sex workers. Data shows the proportion of participants who indicated previous participation in HIV prevention activities and interest in PrEP. The potential limitations of the study are cited.

According to the mine strata pressure bump accidents frequently occurred in shallow depth seam mining of Shenxin Mining Area, the mining activities could make the strain energy increment in the surrounding rock to induce the mine strata pressure bump occurred. An energy equation of the mine strata pressure bump was established. There were three types of the strain energy increment including the static load type, dynamic load type and superposition or mixing type. The site analysis held that there were four types of the mine strata pressure bump existed in Shenxin Mining Area, including the coal mining face with the suspended type hard roof, the strain superposition type gateway, 45° steep inclined seam with falling type roof and 87° almost vertical seam with lever type rock pillar. The paper analyzed the energy resources mode and the major disaster occurred factors of each type mine strata pressure bump. Based on the circumstances, from the mining layout, monitoring and measuring method, danger evaluation, damage releasing method, effect inspection and others, the paper pro- vided relevant countermeasures to prevent and control the mine strata pressure bump. [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]

An emerging HIV epidemic can be seen among men who have sex with men (MSM) in Vietnam, with prevalence as high as 18%. Transactional sex represents a risk factor for HIV transmission/acquisition among MSM globally, particularly in urban contexts, but remains largely underinvestigated in Ho Chi Minh City (HCMC), Vietnam. In 2010, 23 MSM who reported exchanging sex for money in the last month completed a brief survey and semistructured qualitative interview at The Life Centre, a non-governmental organization in HCMC, to assess sociodemographics, individual- and structural-level HIV risk factors and explore acceptable future prevention interventions. Participants' mean age was 24 years. Equal proportions of respondents self-identified as heterosexual/straight, homosexual/gay, and bisexual. Participants had a mean of 158 male clients in the past year, with a median of 60 male clients in the past year (interquartile range [IQR]=70) and reported inconsistent condom use and inaccurate perceptions of HIV risk. Nearly half of the sample reported engaging in unprotected anal sex with a male partner in the past 12 months and one-third with a male client. Major themes that emerged for HIV prevention interventions with male sex workers were those that: (1) focused on individual factors (drug and alcohol use, barriers to condom use, knowledge of asymptomatic STIs, enhancement of behavioral risk-reduction skills, and addressing concomitant mental health issues); (2) incorporated interpersonal and relational contexts (led by peer educators, built interpersonal skills, attended to partner type and intimacy dynamics); and (3) considered the exogenous environments in which individual choices/relationships operate (stigma of being MSM in Vietnam, availability of alternative economic opportunities, and varied sexual venues). HIV prevention efforts are needed that address the specific needs of MSM who engage in transactional sex in HCMC. Universally, MSM endorsed HIV prevention interventions, suggesting a need and desire for efforts in this context. [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]

Based on the symmetric two-lane Nagel–Schreckenberg (STNS) model, a three-lane cellular automaton model between two intersections containing a bus stop with left-turning buses is established in which model the occurrences of vehicle accidents are taken into account. The characteristics of traffic flows with different ratios of left-turn lines are discussed via the simulation experiments. The results indicate that the left-turn lines have more negative effects on capacity, accident rate as well as delay if the stop is located close to the intersections, where the negative effect in a near-side stop is more severe than that in a far-side one. The range of appropriate position for a bus stop without the bottleneck effect becomes more and more narrow with the increase of the ratio of left-turn bus lines. When the inflow is small, a short signal cycle and a reasonable offset are beneficial. When the inflow reaches or exceeds the capacity, a longer signal cycle is helpful. But if the stop position is inappropriate, the increase of cycle fails in reducing the negative effect of left-turning buses and the effectiveness of offset is weakened. [ABSTRACT FROM AUTHOR]