Predictors of parenting stress among gay adoptive fathers in the United States.

The authors examined correlates of parenting stress among 230 gay adoptive fathers across the United States through an Internet survey. As with previous research on adoptive parents, results showed that fathers with less social support, older children, and children who were adopted at older ages reported more parenting stress. Moreover, gay fathers who had a less positive gay identity also reported more parenting stress. These 4 variables accounted for 33% of the variance in parenting stress; effect sizes were medium to large. Our results suggest the importance of social support and a positive gay identity in facilitating successful parenting outcomes among gay adoptive fathers. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Characterization of polyhydroxybutyrate production from Halomonas titanicae KHS3 and manufacturing of electrosprayed nanoparticles

Polyhydroxyalkanoates (PHAs) are biopolymers accumulated by a diversity of bacterial strains as carbon and energy reserve when grown under unbalanced nutritional conditions. Among the wide spectrum of applications for these biopolymers, the generation of nano and microparticles has drawn huge attention. PHA nanoparticles showed a high surface-to-volume ratio that makes them interesting for pharmaceutical uses. Bacteria from the Halomonas genus became interesting tools for biopolymer production in the last years, due to its metabolic plasticity that allows them to grow in a wide spectrum of compounds and salt concentrations. Halomonas titanicae KHS3 was previously isolated based on their ability to grow using aromatic hydrocarbons as the sole carbon source. In this work, the novelty lies in the evaluation of PHA accumulation by H. titanicae KHS3. Accumulation was successfully observed and thoroughly characterized on various carbon sources. Irrespective of the carbon source employed for growth, our experimental conditions consistently yielded PHB as the sole material identified. The truly intriguing aspect of this study is that PHB solutions in glacial acetic acid demonstrated exceptional suitability for electrospraying processing. This groundbreaking development led to the creation of nanoparticles with unique characteristics that hold immense promise for a wide range of applications.     

Laterally scaled Si-Si/sub 0.7/Ge/sub 0.3/ n-MODFETs with f/sub max/>200 GHz and low operating bias

We report on the dc and RF characterization of laterally scaled, Si-SiGe n-MODFETs. Devices with gate length, L/sub g/, of 80 nm had f/sub T/=79 GHz and f/sub max/=212 GHz, while devices with L/sub g/=70 nm had f/sub T/ as high as 92 GHz. The MODFETs displayed enhanced f/sub T/ at reduced drain-to-source voltage, V/sub ds/, compared to Si MOSFETs with similar f/sub T/ at high V/sub ds/.     

Improved DC and RF performance in Si/SiGe n-MODFETs with ion-implanted buried p-well doping

The dc and RF characteristics of Si/SiGe n-MODFETs with buried p-well doping incorporated by ion implantation are reported. At a drain-to-source biasV/sub ds/ of +1 V devices with 140-nm gate length had peak transconductance g/sub m/ of 450 mS/mm, and maximum dc voltage gain A/sub v/ of 20. These devices also had "off-state" drain current I/sub off/ of 0.15 mA/mm at V/sub g/=-0.5 V. Control devices without p-well doping had A/sub v/=8.1 and I/sub off/=13 mA/mm under the same bias conditions. MODFETs with p-well doping had f/sub T/ as high as 72 GHz at V/sub ds/=+1.2 V. These devices also achieved f/sub T/ of 30 GHz at a drain current, I/sub d/, of only 9.8 mA/mm, compared to I/sub d/=30 mA/mm for previously published MODFETs with no p-well doping and similar peak f/sub T/.