Post-spinning modification of electrospun nanofiber nanocomposite from Bombyx mori silk and carbon nanotubes

Electrospinning is an effective procedure for fabricating submicron to nanoscale fibers from synthetic polymer as well as natural proteins. We successfully electrospun regenerated silk protein from cocoons of Bombyx mori to produce random as well as aligned fibers with diameter less than 100 nm. The fibers were characterized using field emission environmental scanning electron microscope (ESEM), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and wide angle X-ray diffraction (WAXD) studies. Post-spinning treatment with methanol and/or stretching and co-electrospinning with single walled carbon nanotubes (CNT) were carried out to alter the strength, toughness, crystallinity and conductivity of silk nanofibers. Addition of just 1% CNT along with post-spinning treatments resulted in 7-fold increase in the strength and 35-fold increase in the modulus of silk nanofibers. Raman spectroscopy confirmed that CNTs were incorporated in the silk fibers. FT-IR spectroscopy and WAXD studies proved that silk-CNT nanofibers had more crystallinity compared to silk nanofibers without CNT. Four-probe method demonstrated that silk-CNT nanofibers had 4 times higher electrical conductivity compared to silk nanofibers without CNT.     

Apolipoprotein B mRNA editing and apolipoprotein gene expression in the liver of hyperinsulinemic fatty zucker rats: Relationship to very low density lipoprotein composition

We previously demonstrated increased apolipoprotein B (apoB) mRNA editing, elevated levels of mRNA for the catalytic component of the apoB mRNA editing complex, apobec-1, and increased secretion of the product of the edited mRNA, apoB48, in very low density lipoproteins (VLDL) in primary cultures of Sprague-Dawley rat hepatocytes following insulin treatment. In order to determine the effect of in vivo hyperinsulinemia on these processes, we determined apoB mRNA editing, apobec-1 expression, hepatic expression of mRNA for apoB and other VLDL apoproteins, and the quantity and composition of plasma VLDL in the hyperinsulinemic fatty Zucker rat. Total apoB mRNA content of the livers of the fatty rats and lean littermates did not differ, however, edited apoB message coding for hepatic apo B48, and abundance of mRNA for the catalytic subunit of the apoB mRNA editing complex, apobec-1, was increased by 1.7-and 3.3-fold, respectively, in fatty rats. ApoCIII mRNA abundance was increased in livers of fatty rats as well, but the abundance of hepatic apoE mRNA in the fatty animal was not different from that of the lean rat. Hepatic apoAI mRNA abundance was also increased in the fatty rats. Associated with increased apoB mRNA editing, was the 1.7-fold increase in the fraction of apoB in plasma as apoB48 in fatty rats. VLDL-triglyceride and-apoB in plasma were 15-and 3-fold higher, respectively, in fatty Zucker rats compared to lean littermates, indicating both enrichment of VLDL with triglycerides and increased accumulation of VLDL particles. Increased hepatic expression of mRNA for apoCIII and apoAI was associated with increased content of apoC (and relative depletion of apoE) in VLDL of fatty rats, and plasma apoAI was increased in fatty Zucker rats, primarily in the HDL fraction. The current study provides further evidence that chronic exposure to high levels of insulin influences both the quantity of and lipid/apoprotein composition of VLDL in plasma. The increased apoC and decreased apoE (as well as increased triglyceride) content of VLDL in the fatty Zucker rat observed in the current study may affect VLDL clearance and therefore may be a factor in the observed accumulation of VLDL in the plasma of the fatty hyperinsulinemic Zucker rats.     

Underdiagnosing and nontreatment of posttraumatic stress disorder in community mental health: A case study.

Research indicates that trauma is extremely prevalent among populations seeking community-based services. However, underdiagnosis and nontreatment of trauma-related disorders is widespread. This study explored how one urban community mental health center (CMHC), serving a severely mentally ill (SMI) population, assessed, diagnosed, and treated reported trauma histories. Results indicate that of the 72 consumers in this sample who reported trauma histories (51%), only 2 were diagnosed with posttraumatic stress disorder (PTSD). Instead, those with a reported trauma history were likely to be diagnosed with affective disorders and were almost seven times as likely to be recommended therapy as were those without a trauma history. However, even those recommended therapy were not likely to receive it. Findings indicate significant barriers to PTSD diagnoses and the receipt of therapy services. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

College students’ social justice interest and commitment: A social-cognitive perspective.

In this study, the authors examined the degree to which social-cognitive career theory (SCCT; R. W. Lent, S. D. Brown, & G. Hackett, 1994) explained the development of social justice interest and commitment. Data from 274 college students and latent variable path modeling were used to test theoretically and empirically derived SCCT direct and indirect effects structural models. The direct effects model estimated the direct effect of social supports and barriers on social justice commitment and the indirect effects model estimated the effect of social supports and barriers indirectly through self-efficacy. Overall, the present findings supported the use of SCCT within the social justice domain, as social justice self-efficacy and outcome expectations were useful in explaining the development of college students’ social justice interest and commitment. The present findings supported the indirect effects model of social justice interest and commitment over the direct effects model. Finally, unique to prior tests of SCCT in vocational and academic domains, social supports and barriers exhibited an indirect effect on commitment through outcome expectations. Study limitations, future directions for research, and implications for facilitating college students’ social justice interest and commitment are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relating indices of knowledge structure coherence and accuracy to skill-based performance: Is there utility in using a combination of indices?

The authors examined the relative criterion-related validity of knowledge structure coherence and two accuracy-based indices (closeness and correlation) as well as the utility of using a combination of knowledge structure indices in the prediction of skill acquisition and transfer. Findings from an aggregation of 5 independent samples (N = 958) whose participants underwent training on a complex computer simulation indicated that coherence and the accuracy-based indices yielded comparable zero-order predictive validities. Support for the incremental validity of using a combination of indices was mixed; the most, albeit small, gain came in pairing coherence and closeness when predicting transfer. After controlling for baseline skill, general mental ability, and declarative knowledge, only coherence explained a statistically significant amount of unique variance in transfer. Overall, the results suggested that the different indices largely overlap in their representation of knowledge organization, but that coherence better reflects adaptable aspects of knowledge organization important to skill transfer. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mother-adolescent physiological synchrony in naturalistic settings: Within-family cortisol associations and moderators.

In this study, the authors examined parent-adolescent cortisol associations in 45 families with adolescent children (24 girls; M age = 15.78 years, SD = 1.44 years). Family members’ salivary cortisol levels were measured seven times a day on 2 typical weekdays. Family members provided reports of demographic and health variables, and adolescents rated parent-child relationship characteristics. After accounting for the effects of time of day and relevant demographic and health control variables on cortisol levels, hierarchical linear models indicated the presence of significant covariation over time in mother-adolescent cortisol (i.e., physiological synchrony). Furthermore, moderating tests revealed that mother-adolescent cortisol synchrony was strengthened among dyads characterized by mothers and adolescents spending more time together, and in families rated higher on levels of parent-youth shared activities and parental monitoring or supervision. Analysis of momentary characteristics indicated that maternal presence at the time of cortisol sampling lowered adolescent cortisol levels but did not account for mother-adolescent cortisol synchrony. Within-family physiological synchrony was amplified in momentary contexts of elevated maternal negative affect and elevated adolescent negative affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Abstractions of data types

The use of abstraction in the context of abstract data types, is investigated. Properties to be checked are formulas in a first order logic under Kleene's 3-valued interpretation. Abstractions are defined as pairs consisting of a congruence and a predicate interpretation. Three types of abstractions are considered,∀∀, ∀∃ and ∃^0,1∀, and for each of them corresponding property preservation results are established. An abstraction refinement property is also obtained. It shows how one can pass from an existing abstraction to a (less) finer one. Finally, equationally specified abstractions in the context of equationally specified abstract data types are discussed and exemplified.On leave from the Department of Computer Science, “Al. I. Cuza” University, Iaşi 740083, RomaniaThe research reported in this paper was partially supported by the program ECO-NET 08112WJ/2004-2005 and by the National University Research Council of Romania, grants CNCSIS 632(28)/2004 and CNCSIS 632(50)/2005.     

Personal hypothesis testing: The role of consistency and self-schema.

We report the results of two experiments that examined the way individuals test hypotheses about themselves. Both experiments were based on the work of Snyder (e.g., Snyder, 1981; Snyder & Skrypnek, 1981), which suggests that individuals have a confirmatory bias when testing hypotheses about others and about themselves. In Experiment 1, we examined the extent to which this bias toward confirmation persists when a negative (e.g., depression) or nonconsistent (not consistent with the individual's evaluation of him- or herself) personal hypothesis is tested. Results suggest that the negative or positive nature of a personal hypothesis does not directly influence the way individuals test their hypothesis. However, the way individuals tested personal hypotheses was influenced by hypothesis consistency. In Experiment 2, we examined the relation of a cognitive schematic variable (i.e., vulnerability for depression) and hypothesis testing. Results suggest that vulnerability is related to the way individuals test a personal hypothesis about depression. Vulnerable, low-depression participants were confirmatory when testing a depression hypothesis, whereas nonvulnerable, low-depression participants were disconfirmatory. We discuss implications for counseling and future directions for research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How does Bennett Woods Elementary School produce such high reading and writing achievement?

The authors developed a grounded theory about how a school serving relatively advantaged children produces high reading and writing achievement compared with schools serving similar populations of students. The school's faculty is reading and writing focused, and students experience many books as they receive explicit, demanding instruction (i.e., about how to read words, comprehend, write) connected to content learning. The school offers a positive, motivating environment. In sum, many elements that potentially supported achievement were identified, including explicit teaching of skills in the context of much reading, writing, and content learning, which is consistent with balanced perspectives on reading and writing development. A major hypothesis in the grounded theory is that even with relatively advantaged populations, great efforts may be required to produce high reading and writing achievement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of sad mood on cognition.

Neuroimaging has identified an overlapping network of brain regions whose activity is modulated by mood and cognition. Studies of depressed individuals have shown changes in perception, attention, memory, and executive functions. This suggests that mood has a pervasive effect on cognition. Direct evidence of the effect of sad mood on cognition is surprisingly limited, however. Published studies have generally addressed a single cognitive ability per study because the fleeting nature of laboratory-induced mood precludes extended testing, and robust findings are limited to mood effects on memory for emotional stimuli. In this study, sad mood was induced and prolonged, enabling the effects of mood to be assessed for an array of abilities, including those that share neural substrates with sad mood and those affected by depression. Sad mood affected memory for emotional words and facial emotion recognition, but not the other processes measured, with a significant nonuniformity of effect over tasks. These results are consistent with circumscribed effects of sad mood on certain emotion-related cognitive processes, but not on cognition more generally. (PsycINFO Database Record (c) 2010 APA, all rights reserved)