572 research outputs found
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Digital Media Dependency, Relational Orientation and Socaial Networking among College Students
This study focused on digital media dependency, relational orientation, and demographic variables as potential factors that were relevant to the usage of social networking websites (e.g., MySpace and Facebook) among college students. A total of 258 (101 male and 157 female) students completed the questionnaire that contains the measures of digital media dependency, relational orientation, social networking media usage, and demographic characteristics. The respondents also indicated specific types of things that they disclose (post) on their social media websites. The results showed that relational orientation is positively correlated with the disclosure (posting) of family photos, friends’ photos, and travel photos and that White students are more likely than others to disclose their gender and favorite things (likes/dislikes) and post their own photos and travel photos. Regression analysis revealed that age is a significant, negative indicator of social media usage, whereas digital media dependency and overall computer usage are significant, positive predictors for the dependent measure. That is, the younger the student and the greater the levels of digital media dependency and overall computer usage, the greater the level of involvement in social networking website
Posttransplantation malignancy in a patient presenting with weight loss and changed bowel habits: a case report
BACKROUND: Advancements in immunosuppressive therapy have significantly improved patient and graft survival following renal transplantation. This is paralleled by an increasing occurrence of posttransplantation malignancy. CASE PRESENTATION: We report on a patient who presented with a history reminding of colon cancer seven years after receiving a kidney transplant. Initial diagnostic imaging seemed to confirm this diagnosis showing a constricting colonic lesion. To our surprise, colonoscopy findings were unremarkable. Review of the imaging studies revealed that the tumor-like picture was caused by the renal graft impressing the intestine. The following search for malignancy in other locations resulted in the diagnosis of glioblastoma multiforme of which the patient died several weeks later. CONCLUSION: Follow-up of renal transplant patients must include screening tests directed at tumor detection. Imaging studies and other tests in this patient group should be interpreted by physicians who are familiar with transplant related peculiarities
Biological control of an agricultural pest protects tropical forests
Though often perceived as an environmentally-risky practice, biological control of invasive species can restore crop yields, ease land pressure and thus contribute to forest conservation. Here, we show how biological control against the mealybug Phenacoccus manihoti (Hemiptera) slows deforestation across Southeast Asia. In Thailand, this newly-arrived mealybug caused an 18% decline in cassava yields over 2009–2010 and an escalation in prices of cassava products. This spurred an expansion of cassava cropping in neighboring countries from 713,000 ha in 2009 to > 1 million ha by 2011: satellite imagery reveals 388%, 330%, 185% and 608% increases in peak deforestation rates in Cambodia, Lao PDR, Myanmar and Vietnam focused in cassava crop expansion areas. Following release of the host-specific parasitoid Anagyrus lopezi (Hymenoptera) in 2010, mealybug outbreaks were reduced, cropping area contracted and deforestation slowed by 31–95% in individual countries. Hence, when judiciously implemented, insect biological control can deliver substantial environmental benefits
Convergence of bark investment according to fire and climate structures ecosystem vulnerability to future change
Fire regimes in savannas and forests are changing over much of the world. Anticipating the impact of these changes requires understanding how plants are adapted to fire. Here we test whether fire imposes a broad selective force on a key fire-tolerance trait, bark thickness, across 572 tree species distributed worldwide. We show that investment in thick bark is a pervasive adaptation in frequently burned areas across savannas and forests in both temperate and tropical regions where surface fires occur. Geographic variability in bark thickness is largely explained by annual burned area and precipitation seasonality. Combining environmental and species distribution data allowed us to assess the vulnerability to future climate and fire conditions: tropical rainforests are especially vulnerable, whereas seasonal forests and savannas are more robust. The strong link between fire and bark thickness provides an avenue for assessing the vulnerability of tree communities to fire and demands inclusion in global models
EUV spectroscopy of Sn5+-Sn(10+)ions in an electron beam ion trap and laser-produced plasmas
Emission spectra from multiply-charged Sn5+ –Sn10+ions are recorded from an electron beam ion trap (EBIT) and from laser-produced plasma (LPP) in the extreme ultraviolet range relevant for nanolithographic applications. Features in the wavelength regime between 12.6 and 20.8 nm are studied. Using the Cowan code, emission line features of the charge-state-resolved Sn ion spectra obtained from the EBIT are identified. Emission features from tin LPP either from a liquid micro-droplet or planar solid target are subsequently identified and assigned to specific charge states using the EBIT data. For the planar solid tin target, the 4d–5p transitions of Sn8+ –Sn10+ions are shown to dominate the long-wavelength part of the measured spectrum and transitions of type 4d–4f + 4p–4d are visible in absorption. For the droplet target case, a clear increase in the charge state distribution with increasing laser intensity is observed. This qualitatively demonstrates the potential of using long-wavelength out-of-band emission features to probe the charge states contributing to the strong unresolved transition array at 13.5 nm relevant for nanolithography
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