Tyrosine phosphorylation of the human guanylyl cyclase C receptor

Tyrosine phosphorylation events are key components of several cellular signal transduction pathways. This study describes a novel method for identification of substrates for tyrosine kinases. Co-expression of the tyrosine kinase EphB1 with the intracellular domain of guanylyl cyclase C (GCC) inEscherichia coli cells resulted in tyrosine phosphorylation of GCC, indicating that GCC is a potential substrate for tyrosine kinases. Indeed, GCC expressed in mammalian cells is tyrosine phosphorylated, suggesting that tyrosine phosphorylation may play a role in regulation of GCC signalling. This is the first demonstration of tyrosine phosphorylation of any member of the family of membrane-associated guanylyl cyclases

Cure and Curse: E. coli Heat-Stable Enterotoxin and Its Receptor Guanylyl Cyclase C

Enterotoxigenic Escherichia coli (ETEC) associated diarrhea is responsible for roughly half a million deaths per year, the majority taking place in developing countries. The main agent responsible for these diseases is the bacterial heat-stable enterotoxin STa. STa is secreted by ETEC and after secretion binds to the intestinal receptor guanylyl cyclase C (GC-C), thus triggering a signaling cascade that eventually leads to the release of electrolytes and water in the intestine. Additionally, GC-C is a specific marker for colorectal carcinoma and STa is suggested to have an inhibitory effect on intestinal carcinogenesis. To understand the conformational events involved in ligand binding to GC-C and to devise therapeutic strategies to treat both diarrheal diseases and colorectal cancer, it is paramount to obtain structural information on the receptor ligand system. Here we summarize the currently available structural data and report on physiological consequences of STa binding to GC-C in intestinal epithelia and colorectal carcinoma cells

The Relationship Between Phonological Working Memory, Phonological Sensitivity, and Incidental Word Learning

Rapid learning of novel vocabulary is crucial to overall success in language acquisition. While the exact mechanisms underlying the acquisition of the lexicon remain under investigation, it is well known that children are able to form rapid initial associations between novel words and their referents during everyday experiences. This ability is referred to as incidental word learning, a process by which a learner makes a sparse initial representation of a word in lexical memory, following only a brief exposure. The cognitive abilities needed to succeed at this task were investigated, specifically by examining the role of working memory and phonological sensitivity in novel word learning by 4-year-olds who were typically developing. It evaluated two competing models, the phonological loop model proposed by Baddeley and colleagues (Baddeley & Hitch, 1974), and the lexical restructuring model of Metsala (Metsala & Walley, 1998; Metsala, 1999). Forty 4 year olds were administered a test of nonword repetition (to investigate phonological working memory), rhyming and phoneme alliteration tasks (to investigate phonological sensitivity), and an incidental word learning task, via a computer-based presentation of a cartoon story. A multiple regression analysis revealed that nonword repetition scores did not contribute significantly to incidental word learning. Phonological sensitivity scores were significant predictors of incidental word learning. These findings provide support for a model of lexical acquisition in which phonological knowledge plays an important role

The Relationship Between Phonological Working Memory, Phonological Sensitivity, and Incidental Word Learning

Rapid learning of novel vocabulary is crucial to overall success in language acquisition. While the exact mechanisms underlying the acquisition of the lexicon remain under investigation, it is well known that children are able to form rapid initial associations between novel words and their referents during everyday experiences. This ability is referred to as incidental word learning, a process by which a learner makes a sparse initial representation of a word in lexical memory, following only a brief exposure. The cognitive abilities needed to succeed at this task were investigated, specifically by examining the role of working memory and phonological sensitivity in novel word learning by 4-year-olds who were typically developing. It evaluated two competing models, the phonological loop model proposed by Baddeley and colleagues (Baddeley & Hitch, 1974), and the lexical restructuring model of Metsala (Metsala & Walley, 1998; Metsala, 1999). Forty 4 year olds were administered a test of nonword repetition (to investigate phonological working memory), rhyming and phoneme alliteration tasks (to investigate phonological sensitivity), and an incidental word learning task, via a computer-based presentation of a cartoon story. A multiple regression analysis revealed that nonword repetition scores did not contribute significantly to incidental word learning. Phonological sensitivity scores were significant predictors of incidental word learning. These findings provide support for a model of lexical acquisition in which phonological knowledge plays an important role

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Not AvailableThe current paper aims to analyze the impact of growers association on improving the vegetable production in Hyderabad-Karnataka regions of Karnataka. The results revealed that majority of sample respondents were belong to middle age group engaged in vegetable growing activities, more than 75 per cent were young and middle age groups. It also revealed that 72 per cent of farmers were using improved varieties as per recommendation for suitable climate and soil conditions. Further, the study also indicates that customized intervention was adopted for staggered sowing in different vegetables and drip irrigation accounted for about 54 and 47 per cent respectively. This suggests that vegetable production can be improved not only by adopting recommended management practices but also through intervention of private sector development initiatives which helps the farmers in constructing appropriate channels of different growers groups to supermarkets and distributors. This kind of intervention approaches will augment area under cultivation especially in dry lands through growers association. The study indicates that strong focus on adoption of recommended cultural and management practices for cultivation such as establishing marketing linkages and utilization of marketing facilities.Not Availabl

Changing skin color: Evolution and modern trends

The present article reviews various evolutionary events that resulted in skin color variation among humans. Skin of the early man is presumed to be colorless as that of the chimpanzees. During the course of evolution, hairless state of skin with sweat glands would have occurred for the purpose of thermoregulation. Thermoregulation was very important for brain development and function. In due course, pigmentation occurred in the naked skin of man in order to offer photo-protection. The physiological demand of vitamin D₃ and folate in human system and the effect of sun-light in their synthesis and metabolism would have further established some changes in the skin color of man in various geographic locations. Although genetics and physiological adaptations have determined human skin color in different groups/races, during the course of civilization, humans have developed a deep desire to change skin color. Current scientific research on development of novel agents for modulation of skin color is likely to benefit in pigmentary disorders and also in psychological well being through the use of cosmetics