University of Rochester

About: University of Rochester is a education organization based out in Rochester, New York, United States. It is known for research contribution in the topics: Population & Laser. The organization has 63915 authors who have published 112762 publications receiving 5484122 citations. The organization is also known as: Rochester University.

Setting limits on children's behavior: The differential effects of controlling vs. informational styles on intrinsic motivation and creativity

Abstract: The imposition of external constraints on an activity has frequently been shown to undermine intrinsic motivation. Given that limits must often be set upon peoples' activities, especially in parenting and education, the present study addressed the question of whether limits can be set without undermining intrinsic motivation for the activity being limited. Using cognitive evaluation theory, contrasting limit setting styles of either a controlling or informational nature, or no limits, were placed upon forty-four first- and second-grade children engaged in a painting activity. The intrinsic motivation, enjoyment, creativity, and quality of artistic production were expected to be decreased by controlling limits relative to informational and no-limits, which were not expected to differ from each other. The results provided substantial support for these predictions, suggesting that limits can be set without undermining intrinsic motivation if they are informational in nature. Support was also found for the consensual assessment of creativity method recently developed by Amabile (1982a). Results ofthe study are discussed along with the general relation between creativity and intrinsic motivation. Recent findings in motivational research suggest that imposing external controls or constraints on an actiyity can haye a deleterious effect on subsequent intrinsic motiyation. Beginning with Deci's (1971) demonstration that tangible rewards for doing a task can negatiyely affect intrinsic motiyation, many other factors that haye a similar impact haye been identified, including symbolic rewards (Lepper, Greene, & Nisbett, 1973), yerbal praise (Deci, Cascio, &

Mitochondrial calcium transport: physiological and pathological relevance

Abstract: Since the initiation of work on mitochondrial Ca2+ transport in the early 1960s, the relationship between experimental observations and physiological function has often seemed enigmatic. Why, for example, should an organelle dedicated to the crucial task of producing approximately 95% of the cell's ATP sequester Ca2+, sometimes in preference to phosphorylating ADP? Why should there be two separate efflux mechanisms, the Na+ independent and the Na+ dependent, both thought until recently to be driven exclusively either directly or indirectly by the energy of the pH gradient? Does intramitochondrial free Ca2+ concentration control metabolism? Is there evidence for any separate function of the mitochondrial Ca2+ transport mechanisms under pathological conditions? What is the relationship between mitochondrial Ca2+ transport, the mitochondrial membrane permeability transition, and irreversible cell damage under pathological conditions? First, we review what is known about control of metabolism, evidence for a role for intramitochondrial Ca2+ in control of metabolism, the cellular conditions under which mitochondria are exposed to Ca2+, characteristics of the mitochondrial Ca2+ transport mechanisms including the permeability transition, and evidence for and against mitochondrial Ca2+ uptake in vivo. Then the questions listed above and others are addressed from the perspective of the characteristics of the mechanisms of mitochondrial Ca2+ transport.

Identification of a pathogenicity island required for Salmonella survival in host cells

Abstract: We have identified a region unique to the Salmonella typhimurium chromosome that is essential for virulence in mice. This region harbors at least three genes: two (spiA and spiB) encode products that are similar to proteins found in type III secretion systems, and a third (spiR) encodes a putative regulator. A strain with a mutation in spiA was unable to survive within macrophages but displayed wild-type levels of epithelial cell invasion. The culture supernatants of the spi mutants lacked a modified form of flagellin, which was present in the supernatant of the wild-type strain. This suggests that the Spi secretory apparatus exports a protease, or a protein that can alter the activity of a secreted protease. The "pathogenicity island" harboring the spi genes may encode the virulence determinants that set Salmonella apart from other enteric pathogens.

Antimicrobials from human skin commensal bacteria protect against Staphylococcus aureus and are deficient in atopic dermatitis

Abstract: The microbiome can promote or disrupt human health by influencing both adaptive and innate immune functions. We tested whether bacteria that normally reside on human skin participate in host defense by killing Staphylococcus aureus, a pathogen commonly found in patients with atopic dermatitis (AD) and an important factor that exacerbates this disease. High-throughput screening for antimicrobial activity against S. aureus was performed on isolates of coagulase-negative Staphylococcus (CoNS) collected from the skin of healthy and AD subjects. CoNS strains with antimicrobial activity were common on the normal population but rare on AD subjects. A low frequency of strains with antimicrobial activity correlated with colonization by S. aureus The antimicrobial activity was identified as previously unknown antimicrobial peptides (AMPs) produced by CoNS species including Staphylococcus epidermidis and Staphylococcus hominis These AMPs were strain-specific, highly potent, selectively killed S. aureus, and synergized with the human AMP LL-37. Application of these CoNS strains to mice confirmed their defense function in vivo relative to application of nonactive strains. Strikingly, reintroduction of antimicrobial CoNS strains to human subjects with AD decreased colonization by S. aureus These findings show how commensal skin bacteria protect against pathogens and demonstrate how dysbiosis of the skin microbiome can lead to disease.

Spin spin correlation functions for the two-dimensional Ising model: Exact theory in the scaling region

Abstract: We compute exactly the spin-spin correlation functions 〈σ0,0σM,N〉 for the two-dimensional Ising model on a square lattice in zero magnetic field for T>Tc and T