Thermal stability of CdZnO/ZnO multi-quantum-wells

The thermal stability of CdZnO/ZnO multi-quantum-well (MQW) structures was studied using rapid thermal annealing in nitrogen from 300 to 750 degrees C. Photoluminescence (PL) emission from the MQWs was studied while varying the annealing temperature and time. For 15 min annealings, the PL center wavelength showed a 7 nm reduction for temperatures up to 650 degrees C. Above 650 degrees C, the wavelength changed rapidly, with a 50 nm reduction at 750 degrees C. Annealing at 700 degrees C for up to 20 min produced a systematic reduction in PL wavelength up to 39 nm. The data suggest that CdZnO/ZnO MQWs are relatively stable for nitrogen annealing below 650 degrees C for times up to 15 min

How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers

Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program

Zaštitno djelovanje selenija protiv prekomjerne ekspresije apoptotskih gena povezanih s karcinomom u štakora izloženih o-krezolu

Cresols are monomethyl derivatives of phenol frequently used as solvents and intermediates in the production of disinfectants, fragrances, pesticides, dyes, and explosives, which is probably why they are widely distributed in the environment. General population may be exposed to cresols mainly through inhalation of contaminated air. In this study we evaluated the toxicological effects of o-cresol on differential gene expression profile of rat liver and prostate. Experiments were conducted on 80 male rats, 60 of which were exposed to o-cresol (1.5 g kg-1, 5 g kg-1, or 15 g kg-1) through feed for 8 weeks. Three groups of rats were supplemented with 0.1 mg kg-1 selenium (Se, in the form of, sodium selenite) in addition to o-cresol to evaluate its effectiveness against o-cresol toxicity. Control group received neither o-cresol nor Se, while one group received Se alone. Survival was similar between the exposed and control animals. Rats exposed to 15 g kg-1 of o-cresol showed a 16 % loss in body weight by the end of the study, which may have been related to o-cresol making feed unpalatable at this concentration. Liver and prostate tissue samples were collected at the end of the treatment. mRNA analysis revealed that apoptotic genes (CYP3A, COX-2, PPARγ, BAX, BCL2, AKT-1, and PKCα) related to cancer were up-regulated in liver and prostate tissues isolated from groups exposed to 5 g kg-1 and 15 g kg-1 o-cresol in comparison to control. Changes in gene expression profile were prevented when rats were supplemented with Se. The exact mechanisms underlying its protective effect remain to be clarified by future studies.Krezoli su monometilni derivati fenola koji se često rabe kao otapala te kao posrednici u proizvodnji dezinfekcijskih sredstava, mirisa, pesticida, boja i eksploziva. Otuda i njihova rasprostranjenost u okolišu. Opća je populacija izložena krezolima uglavnom putem zraka. U ovome se toksikološkom istraživanju ocijenilo djelovanje o-krezola, jednoga od tri krezolova izomera, na ekspresiju gena u tkivima jetre i prostate mužjaka štakora. Istraživanje je provedeno na 80 mužjaka, od kojih je 60 tijekom osam tjedana bilo izloženo o-krezolu (1,5 g kg-1, 5 g kg-1, odnosno 15 g kg-1) preko krmiva. Tri skupine štakora primale su uz o-krezol nadomjestak selenija u dozi od 0.1 mg kg-1 (Se, u obliku natrijeva selenita) radi ocjene njegove djelotvornosti protiv toksičnosti o-krezola. Kontrolna skupina nije primala ni o-krezol ni Se, dok je jedna skupina primala samo Se. Preživljenje je bilo podjednako u svih skupina životinja. Štakori izloženi najvišoj dozi o-krezola (15 g kg-1) imali su 16 % manju tjelesnu masu od kontrolne skupine na kraju ispitivanja, što može biti povezano s lošim okusom krmiva zbog primjese visoke doze o-krezola. S istekom osmotjednoga izlaganja o-krezolu životinje su eutanazirane te su prikupljeni uzorci tkiva jetre i prostate. Analiza m-RNA pokazala je značajno povišenu ekspresiju apoptotskih gena CYP3A, COX-2, PPARγ, BAX, BCL2, AKT-1 i PKCα, koji su povezani s nastankom karcinoma u skupinama štakora izloženim o-krezolu (5 g kg-1 i 15 g kg-1 u odnosu na kontrolu. Ova je prekomjerna ekspresija poništena u štakora koji su primali selenij. Još nisu jasni mehanizmi iza ovoga zaštitnog djelovanja, na što će odgovoriti buduća istraživanja

Investigation of the Performance of the New Orleans Flood Protection System in Hurricane Katrina on August 29, 2005: Volume 1

This report presents the results of an investigation of the performance of the New Orleans regional flood protection system during and after Hurricane Katrina, which struck the New Orleans region on August 29, 2005. This event resulted in the single most costly catastrophic failure of an engineered system in history. Current damage estimates at the time of this writing are on the order of $100 to$200 billion in the greater New Orleans area, and the official death count in New Orleans and southern Louisiana at the time of this writing stands at 1,293, with an additional 306 deaths in nearby southern Mississippi. An additional approximately 300 people are currently still listed as “missing”; it is expected that some of these missing were temporarily lost in the shuffle of the regional evacuation, but some of these are expected to have been carried out into the swamps and the Gulf of Mexico by the storm’s floodwaters, and some are expected to be recovered in the ongoing sifting through the debris of wrecked homes and businesses, so the current overall regional death count of 1,599 is expected to continue to rise a bit further. More than 450,000 people were initially displaced by this catastrophe, and at the time of this writing more than 200,000 residents of the greater New Orleans metropolitan area continue to be displaced from their homes by the floodwater damages from this storm event. This investigation has targeted three main questions as follow: (1) What happened?, (2) Why?, and (3) What types of changes are necessary to prevent recurrence of a disaster of this scale again in the future? To address these questions, this investigation has involved: (1) an initial field reconnaissance, forensic study and data gathering effort performed quickly after the arrival of Hurricanes Katrina (August 29, 2005) and Rita (September 24, 2005), (2) a review of the history of the regional flood protection system and its development, (3) a review of the challenging regional geology, (4) detailed studies of the events during Hurricanes Katrina and Rita, as well as the causes and mechanisms of the principal failures, (4) studies of the organizational and institutional issues affecting the performance of the flood protection system, (5) observations regarding the emergency repair and ongoing interim levee reconstruction efforts, and (6) development of findings and preliminary recommendations regarding changes that appear warranted in order to prevent recurrence of this type of catastrophe in the future. In the end, it is concluded that many things went wrong with the New Orleans flood protection system during Hurricane Katrina, and that the resulting catastrophe had it roots in three main causes: (1) a major natural disaster (the Hurricane itself), (2) the poor performance of the flood protection system, due to localized engineering failures, questionable judgments, errors, etc. involved in the detailed design, construction, operation and maintenance of the system, and (3) more global “organizational” and institutional problems associated with the governmental and local organizations responsible for the design, construction, operation, maintenance and funding of the overall flood protection system

Host genotype and time dependent antigen presentation of viral peptides: predictions from theory

The rate of progression of HIV infected individuals to AIDS is known to vary with the genotype of the host, and is linked to their allele of human leukocyte antigen (HLA) proteins, which present protein degradation products at the cell surface to circulating T-cells. HLA alleles are associated with Gag-specific T-cell responses that are protective against progression of the disease. While Pol is the most conserved HIV sequence, its association with immune control is not as strong. To gain a more thorough quantitative understanding of the factors that contribute to immunodominance, we have constructed a model of the recognition of HIV infection by the MHC class I pathway. Our model predicts surface presentation of HIV peptides over time, demonstrates the importance of viral protein kinetics, and provides evidence of the importance of Gag peptides in the long-term control of HIV infection. Furthermore, short-term dynamics are also predicted, with simulation of virion-derived peptides suggesting that efficient processing of Gag can lead to a 50% probability of presentation within 3 hours post-infection, as observed experimentally. In conjunction with epitope prediction algorithms, this modelling approach could be used to refine experimental targets for potential T-cell vaccines, both for HIV and other viruses

Whole Genome Deep Sequencing of HIV-1 Reveals the Impact of Early Minor Variants Upon Immune Recognition During Acute Infection

Deep sequencing technologies have the potential to transform the study of highly variable viral pathogens by providing a rapid and cost-effective approach to sensitively characterize rapidly evolving viral quasispecies. Here, we report on a high-throughput whole HIV-1 genome deep sequencing platform that combines 454 pyrosequencing with novel assembly and variant detection algorithms. In one subject we combined these genetic data with detailed immunological analyses to comprehensively evaluate viral evolution and immune escape during the acute phase of HIV-1 infection. The majority of early, low frequency mutations represented viral adaptation to host CD8+ T cell responses, evidence of strong immune selection pressure occurring during the early decline from peak viremia. CD8+ T cell responses capable of recognizing these low frequency escape variants coincided with the selection and evolution of more effective secondary HLA-anchor escape mutations. Frequent, and in some cases rapid, reversion of transmitted mutations was also observed across the viral genome. When located within restricted CD8 epitopes these low frequency reverting mutations were sufficient to prime de novo responses to these epitopes, again illustrating the capacity of the immune response to recognize and respond to low frequency variants. More importantly, rapid viral escape from the most immunodominant CD8+ T cell responses coincided with plateauing of the initial viral load decline in this subject, suggestive of a potential link between maintenance of effective, dominant CD8 responses and the degree of early viremia reduction. We conclude that the early control of HIV-1 replication by immunodominant CD8+ T cell responses may be substantially influenced by rapid, low frequency viral adaptations not detected by conventional sequencing approaches, which warrants further investigation. These data support the critical need for vaccine-induced CD8+ T cell responses to target more highly constrained regions of the virus in order to ensure the maintenance of immunodominant CD8 responses and the sustained decline of early viremia

Dissecting the Dynamics of HIV-1 Protein Sequence Diversity

10.1371/journal.pone.0059994PLoS ONE84

Genetics of self-reported risk-taking behaviour, trans-ethnic consistency and relevance to brain gene expression

Risk-taking behaviour is an important component of several psychiatric disorders, including attention-deficit hyperactivity disorder, schizophrenia and bipolar disorder. Previously, two genetic loci have been associated with self-reported risk taking and significant genetic overlap with psychiatric disorders was identified within a subsample of UK Biobank. Using the white British participants of the full UK Biobank cohort (n = 83,677 risk takers versus 244,662 controls) for our primary analysis, we conducted a genome-wide association study of self-reported risk-taking behaviour. In secondary analyses, we assessed sex-specific effects, trans-ethnic heterogeneity and genetic overlap with psychiatric traits. We also investigated the impact of risk-taking-associated SNPs on both gene expression and structural brain imaging. We identified 10 independent loci for risk-taking behaviour, of which eight were novel and two replicated previous findings. In addition, we found two further sex-specific risk-taking loci. There were strong positive genetic correlations between risk-taking and attention-deficit hyperactivity disorder, bipolar disorder and schizophrenia. Index genetic variants demonstrated effects generally consistent with the discovery analysis in individuals of non-British White, South Asian, African-Caribbean or mixed ethnicity. Polygenic risk scores comprising alleles associated with increased risk taking were associated with lower white matter integrity. Genotype-specific expression pattern analyses highlighted DPYSL5, CGREF1 and C15orf59 as plausible candidate genes. Overall, our findings substantially advance our understanding of the biology of risk-taking behaviour, including the possibility of sex-specific contributions, and reveal consistency across ethnicities. We further highlight several putative novel candidate genes, which may mediate these genetic effects