Perceptual expertise improves category detection in natural scenes

There is much debate about how detection, categorization, and within-category identification relate to one another during object recognition. Whether these tasks rely on partially shared perceptual mechanisms may be determined by testing whether training on one of these tasks facilitates performance on another. In the present study we asked whether expertise in discriminating objects improves the detection of these objects in naturalistic scenes. Self-proclaimed car experts (N = 34) performed a car discrimination task to establish their level of expertise, followed by a visual search task where they were asked to detect cars and people in hundreds of photographs of natural scenes. Results revealed that expertise in discriminating cars was strongly correlated with car detection accuracy. This effect was specific to objects of expertise, as there was no influence of car expertise on person detection. These results indicate a close link between object discrimination and object detection performance, which we interpret as reflecting partially shared perceptual mechanisms and neural representations underlying these tasks: the increased sensitivity of the visual system for objects of expertise – as a result of extensive discrimination training – may benefit both the discrimination and the detection of these objects. Alternative interpretations are also discussed

Zinc-Alpha 2-Glycoprotein Gene Expression in Adipose Tissue Is Related with Insulin Resistance and Lipolytic Genes in Morbidly Obese Patients

10.1371/journal.pone.003326

The history of falls and the association of the timed up and go test to falls and near-falls in older adults with hip osteoarthritis

Abstract Background Falling accounts for a significant number of hospital and long-term care admissions in older adults. Many adults with the combination of advancing age and functional decline associated with lower extremity osteoarthritis (OA), are at an even greater risk. The purpose of this study was to describe fall and near-fall history, location, circumstances and injuries from falls in a community-dwelling population of adults over aged 65 with hip OA and to determine the ability of the timed up and go test (TUG) to classify fallers and near-fallers. Method A retrospective observational study of 106 older men and women with hip pain for six months or longer, meeting a clinical criteria for the presence of hip OA at one or both hips. An interview for fall and near-fall history and administration of the TUG were administered on one occasion. Results Forty-five percent of the sample had at least one fall in the past year, seventy-seven percent reported occasional or frequent near-falls. The majority of falls occurred during ambulation and ascending or descending steps. Forty percent experienced an injury from the fall. The TUG was not associated with history of falls, but was associated with near-falls. Higher TUG scores occurred for those who were older, less mobile, and with greater number of co-morbidities. Conclusion A high percentage of older adults with hip OA experience falls and near-falls which may be attributed to gait impairments related to hip OA. The TUG could be a useful screening instrument to predict those who have frequent near-falls, and thus might be useful in predicting risk of future falls in this population.</p

An individually-tailored multifactorial intervention program for older fallers in a middle-income developing country: Malaysian Falls Assessment and Intevention Trial (MyFAIT)

Background: In line with a rapidly ageing global population, the rise in the frequency of falls will lead to increased healthcare and social care costs. This study will be one of the few randomized controlled trials evaluating a multifaceted falls intervention in a low-middle income, culturally-diverse older Asian community. The primary objective of our paper is to evaluate whether individually tailored multifactorial interventions will successfully reduce the number of falls among older adults. Methods: Three hundred community-dwelling older Malaysian adults with a history of (i) two or more falls, or (ii) one injurious fall in the past 12 months will be recruited. Baseline assessment will include cardiovascular, frailty, fracture risk, psychological factors, gait and balance, activities of daily living and visual assessments. Fallers will be randomized into 2 groups: to receive tailored multifactorial interventions (intervention group); or given lifestyle advice with continued conventional care (control group). Multifactorial interventions will target 6 specific risk factors. All participants will be re-assessed after 12 months. The primary outcome measure will be fall recurrence, measured with monthly falls diaries. Secondary outcomes include falls risk factors; and psychological measures including fear of falling, and quality of life.Previous studies evaluating multifactorial interventions in falls have reported variable outcomes. Given likely cultural, personal, lifestyle and health service differences in Asian countries, it is vital that individually-tailored multifaceted interventions are evaluated in an Asian population to determine applicability of these interventions in our setting. If successful, these approaches have the potential for widespread application in geriatric healthcare services, will reduce the projected escalation of falls and fall-related injuries, and improve the quality of life of our older community

Epistasis between COMT and MTHFR in Maternal-Fetal Dyads Increases Risk for Preeclampsia

Preeclampsia is a leading cause of perinatal morbidity and mortality. This disorder is thought to be multifactorial in origin, with multiple genes, environmental and social factors, contributing to disease. One proposed mechanism is placental hypoxia-driven imbalances in angiogenic and anti-angiogenic factors, causing endothelial cell dysfunction. Catechol-O-methyltransferase (Comt)-deficient pregnant mice have a preeclampsia phenotype that is reversed by exogenous 2-methoxyestradiol (2-ME), an estrogen metabolite generated by COMT. 2-ME inhibits Hypoxia Inducible Factor 1α, a transcription factor mediating hypoxic responses. COMT has been shown to interact with methylenetetrahydrofolate reductase (MTHFR), which modulates the availability of S-adenosylmethionine (SAM), a COMT cofactor. Variations in MTHFR have been associated with preeclampsia. By accounting for allelic variation in both genes, the role of COMT has been clarified. COMT allelic variation is linked to enzyme activity and four single nucleotide polymorphisms (SNPs) (rs6269, rs4633, rs4680, and rs4818) form haplotypes that characterize COMT activity. We tested for association between COMT haplotypes and the MTHFR 677 C→T polymorphism and preeclampsia risk in 1103 Chilean maternal-fetal dyads. The maternal ACCG COMT haplotype was associated with reduced risk for preeclampsia (P = 0.004), and that risk increased linearly from low to high activity haplotypes (P = 0.003). In fetal samples, we found that the fetal ATCA COMT haplotype and the fetal MTHFR minor “T” allele interact to increase preeclampsia risk (p = 0.022). We found a higher than expected number of patients with preeclampsia with both the fetal risk alleles alone (P = 0.052) and the fetal risk alleles in combination with a maternal balancing allele (P<0.001). This non-random distribution was not observed in controls (P = 0.341 and P = 0.219, respectively). Our findings demonstrate a role for both maternal and fetal COMT in preeclampsia and highlight the importance of including allelic variation in MTHFR

Quantitative and Qualitative Stem Rust Resistance Factors in Barley Are Associated with Transcriptional Suppression of Defense Regulons

Stem rust (Puccinia graminis f. sp. tritici; Pgt) is a devastating fungal disease of wheat and barley. Pgt race TTKSK (isolate Ug99) is a serious threat to these Triticeae grain crops because resistance is rare. In barley, the complex Rpg-TTKSK locus on chromosome 5H is presently the only known source of qualitative resistance to this aggressive Pgt race. Segregation for resistance observed on seedlings of the Q21861 × SM89010 (QSM) doubled-haploid (DH) population was found to be predominantly qualitative, with little of the remaining variance explained by loci other than Rpg-TTKSK. In contrast, analysis of adult QSM DH plants infected by field inoculum of Pgt race TTKSK in Njoro, Kenya, revealed several additional quantitative trait loci that contribute to resistance. To molecularly characterize these loci, Barley1 GeneChips were used to measure the expression of 22,792 genes in the QSM population after inoculation with Pgt race TTKSK or mock-inoculation. Comparison of expression Quantitative Trait Loci (eQTL) between treatments revealed an inoculation-dependent expression polymorphism implicating Actin depolymerizing factor3 (within the Rpg-TTKSK locus) as a candidate susceptibility gene. In parallel, we identified a chromosome 2H trans-eQTL hotspot that co-segregates with an enhancer of Rpg-TTKSK-mediated, adult plant resistance discovered through the Njoro field trials. Our genome-wide eQTL studies demonstrate that transcript accumulation of 25% of barley genes is altered following challenge by Pgt race TTKSK, but that few of these genes are regulated by the qualitative Rpg-TTKSK on chromosome 5H. It is instead the chromosome 2H trans-eQTL hotspot that orchestrates the largest inoculation-specific responses, where enhanced resistance is associated with transcriptional suppression of hundreds of genes scattered throughout the genome. Hence, the present study associates the early suppression of genes expressed in this host–pathogen interaction with enhancement of R-gene mediated resistance

Haloquadratum walsbyi yields a versatile, NAD+/NADP+ dual affinity, thermostable, alcohol dehydrogenase (HwADH)

This study presents the first example of an alcohol dehydrogenase (ADH) from the halophilic archaeum Haloquadratum walsbyi (HwADH). A hexahistidine-tagged recombinant HwADH was heterologously overexpressed in Haloferax volcanii. HwADH was purified in one step and was found to be thermophilic with optimal activity at 65 °C. HwADH was active in the presence of 10 % (v/v) organic solvent. The enzyme displayed dual cofactor specificity and a broad substrate scope, maximum activity was detected with benzyl alcohol and 2-phenyl-1- propanol. HwADH accepted aromatic ketones, acetophenone and phenylacetone as substrates. The enzyme also accepted cyclohexanol and aromatic secondary alcohols, 1- phenylethanol and 4-phenyl-2-butanol. H. walsbyi may offer an excellent alternative to other archaeal sources to expand the toolbox of halophilic biocatalysts