Biodegradable quantum dot nanocomposites enable live cell labeling and imaging of cytoplasmic targets

Semiconductor quantum dots (QDs) offer great promise as the new generation of fluorescent probes to image and study biological processes. Despite their superior optical properties, QDs for live cell monitoring and tracking of cytoplasmic processes remain limited due to inefficient delivery methods available, altered state or function of cells during the delivery process and the requirement of surface-functionalized QDs for specific labeling of subcellular structures. Here, we present a noninvasive method to image subcellular structures in live cells using bioconjugated QD nanocomposites. By incorporating antibody-coated QDs within biodegradable polymeric nanospheres, we have designed a bioresponsive delivery system that undergoes endolysosomal to cytosolic translocation via pH-dependent reversal of nanocomposite surface charge polarity. Upon entering the cytosol, the polymer nanospheres undergo hydrolysis thus releasing the QD bioconjugates. This approach facilitates multiplexed labeling of subcellular structures inside live cells without the requirement of cell fixation or membrane permeabilization. As compared to conventional intracellular delivery techniques, this approach allows the high throughput cytoplasmic delivery of QDs with minimal toxicity to the cell. More importantly, this development demonstrates an important rational strategy for the design of a multifunctional nanosystem for biological applications.     

A heterostructured SnO2–TiO2 thin film prepared by Langmuir–Blodgett technique

SnO₂–TiO₂ heterostructure films were prepared through Langmuir–Blodgett (LB) route. LB films of octadecyl amine (ODA)–titanyl oxalate multilayer deposited on Si (100) and decomposed at 600 °C showed rutile and anatase phases of ultrathin TiO₂ film. Subsequently, multilayer LB film of ODA–stannate deposited on the pre deposited TiO₂ film after decomposition at 600 °C resulted in thin SnO₂ films on the TiO₂ thin film. The phase analysis of the SnO₂–TiO₂ film showed cassiterite phase of SnO₂ as well as the rutile/anatase mixture of TiO₂ indicating a SnO₂–TiO₂ heterostructured film. Surface morphology of the pure TiO₂ film and SnO₂–TiO₂ film were analyzed by using AFM. Electrical characterization by AC impedance analysis suggested SnO₂–TiO₂ heterostructure formation. DC current voltage measurement showed increase in photocurrent indicating visible light absorption and efficient charge separation under the sunlight type radiation.     

Ordinal judgments of symbolic stimuli by capuchin monkeys (Cebus apella) and rhesus monkeys (Macaca mulatta): The effects of differential and nondifferential reward.

Ordinal learning was investigated in capuchin monkeys (Cebus apella) and rhesus monkeys (Macaca mulatta). In Experiment 1, both species were presented with pairings of the Arabic numerals 0 to 9. Some monkeys were given food rewards equal to the value of the numeral selected and some were rewarded with a single pellet only for choosing the higher numeral within the pair. Both species learned to select the larger numeral, but only rhesus monkeys that were differentially rewarded performed above chance levels when presented with novel probe pairings. In Experiment 2, the monkeys were first presented with arrays of 5 familiar numerals (from the range 0 to 9) and then arrays of 5 novel letters (from the range A to J) with the same reward outcomes in place as in Experiment 1. Both species performed better with the numerals, suggesting that an ordinal sequence of all stimuli had been learned during Experiment 1, rather than a matrix of two-choice discriminations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer of fluency across repetitions and across texts.

Three experiments examined transfer of reading fluency across repeated readings of the same text and across related but different texts with a total of 102 college students. In Exp 1, it was found that a paraphrase that altered the syntactic structure of sentences but not the lexical identity of main concepts or the unfolding of the message was reprocessed as an unchanged repetition. However, when the paraphrase altered the lexical identity of main concepts, there was a loss in the repetition benefit. In Exps 2 and 3, there was transfer from a representation of 1 text to the reading of a 2nd text only if the messages were continuous. Results are discussed in terms of the influence of episodic text representations on reading fluency. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

AutoRELAX: automatically RELAXing a goal model to address uncertainty

Dynamically adaptive systems (DAS) must cope with system and environmental conditions that may not have been fully understood or anticipated during development. RELAX is a fuzzy logic-based specification language for identifying and assessing sources of environmental uncertainty, thereby making DAS requirements more tolerant of unanticipated conditions. This paper presents AutoRELAX, an approach that automatically generates RELAXed goal models to address environmental uncertainty. Specifically, AutoRELAX identifies goals to RELAX, which RELAX operators to apply, and the shape of the fuzzy logic function that establishes the goal satisfaction criteria. AutoRELAX generates different solutions by making tradeoffs between minimizing the number of RELAXed goals and maximizing delivered functionality by reducing the number of adaptations triggered by minor and adverse environmental conditions. In a recent extension, AutoRELAX uses a stepwise adaptation of weights to balance these two competing concerns and thereby further improve the utility of AutoRELAX. We apply it to two industry-based applications involving network management and a robotic controller, respectively.     

Relapse as a model of nonadherence to dietary treatment of diabetes.

Tested the generality of G. A. Marlatt and J. R. Gordon's (1980, 1985) model of dietary lapse. 46 adults with insulin-dependent diabetes mellitus (IDDM) and 43 obese adults with non-IDDM were interviewed regarding dietary violations. Most episodes occurred in a limited range of high-risk situations. Although the 2 groups lapsed in similar situations, there was a tendency for the IDDM Ss to report a larger proportion of lapses in situations characterized by negative emotions. Approximately 27% of the lapses occurred when the S was busy with a competing activity or had no choice, and these lapses did not fit into Marlatt and Gordon's coding schema. Violations usually were errors of omission rather than errors of commission. Results suggest that most instances of nonadherence were intermittent lapses that did not develop into full-blown relapses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Learning disabilities and brain function: A neuropsychological approach (rev. ed.).

Reviews the book, Learning disabilities and brain function: A neuropsychological approach (rev. ed.), by William H. Gaddes (1985). The neurological substrata of intellectual functioning have long been a topic of interest to psychologists; but with the development of the learning disabilities classification and the interest in the brain, learning behavior relationships have expanded to include the entire educational community. This book, like the first edition, has been designed to draw together the neuropsychologist, the school psychologist, and teacher in common cause. In doing so, it helps to bridge a traditional interdisciplinary communications gap. There is a need for neuropsychological training of school psychologists. This book helps to bring this knowledge to bear directly on practice in the field of learning disabilities. Advantages of the second edition over the first are the inclusion of discussions of new techniques (i.e., new brain scanning devices and methods, new applications of dichotic listening) and expanded examples of case studies. The reviewers feel that Gaddes has provided an updated, thorough treatment of the role of neuropsychology in the diagnosis and remediation of the learning-disabled child. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrauterine alcohol and nicotine exposure: Attention and reaction time in 4-year-old children.

452 4-yr-old children whose mothers had been interviewed during pregnancy regarding alcohol, smoking, and drug use were examined with a computer-controlled vigilance task to assess attention and RT. Multiple regression analyses were used to permit testing of alcohol and nicotine effects after adjusting for the S's birth order, maternal education, nutrition, and caffeine (and alcohol or nicotine, whichever was relevant). Maternal alcohol use during early pregnancy was significantly related to poor attention (more errors of omission and more errors of commission) and longer RT. Maternal cigarette use was significantly related to poor attention and poor orientation to the display board. Results support the hypothesis that both alcohol use (even in the absence of self-reported problems with alcohol abuse) and cigarette use by pregnant women are related to poorer attention in preschool age offspring, even when adjusting for a variety of potentially confounding variables. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender dysphoria, gender reorientation, and the clinical management of transsexualism.

Conducted 2 studies of gender dysphoria and postoperative adjustment by transsexuals. Study 1 examined the relation of gender reorientation (approximation of the status of the opposite biological sex) to psychological adjustment in gender dysphorics. Three S groups (75 heterosexual males, mean age 36.7 yrs; 85 homosexual males, mean age 29.8 yrs; and 103 biological females, mean age 27.4 yrs) were studied in multiple regression analyses, with psychological symptoms as criteria and measures of 3 roughly sequential components of gender reorientation (role changes, document changes, and physical changes), age, and education as predictors. Psychological complaints correlated negatively with the earliest phase of reorientation for females and with the later phases for males. Age and education bore little relation to current symptoms. Results suggest that psychological improvement accompanies gender reorientation in both male and female gender dysphorics; the greatest degree of improvement is seen earlier in the process for females. Ss in Study 2 were postoperative transsexuals (32 homosexual males, mean age 33.2 yrs; 9 heterosexual males, mean age 47.7 yrs; and 38 biological females, mean age 32.6 yrs) at least 1 yr after surgery. Follow-up rate was 77.5% for all Ss meeting the 1-yr criterion. Satisfaction with surgery was high, and psychosocial adjustment was acceptable for the majority. Results of both studies support the rationale for clinical intervention in aid of gender reorientation in selected cases. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender differences in moral reasoning.

Explored the possibility that socialization into different sex roles for men and women may contribute to the observed sex difference in moral development. 40 undergraduates were classified as either masculine, feminine, or androgynous according to the Bem Sex-Role Inventory and were administered the Moral Judgment Interview (MJI). For half the Ss, the central character in the MJI dilemmas was a male and for the remaining half, a female. Results reveal that males, when judging from the perspective of a female character, provided reasons for her actions congruent with the Stage 3 level of moral reasoning. However, for the same action portrayed by a male character, reasons for his behavior were in accord with Stage 4. No difference for the female judges was found between the characters of either sex. Regardless of the protagonist's sex, Ss scored at Stage 3. Ss' moral reasoning did not differ according to their sex-role classification. Males, however, held more strongly than females the belief that male decisions on morality are based on law-and-order reasoning, and female decisions are made from an emotional perspective. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)