Cyclic stretch down-regulates calcium transporter gene expression in neonatal rat ventricular myocytes

Abnormal intracellular Ca2+ handling in hypertrophied and failing hearts is partly due to changes in Ca2+ transporter gene expression, but the mechanisms responsible for these alterations remain largely unknown. We previously showed that intrinsic mechanical load (i.e. spontaneous contractile activity) induced myocyte hypertrophy, and down-regulated SR Ca2+ ATPase (SERCA2) gene expression in cultured neonatal rat ventricular myocytes (NRVM). In the present study, we examined whether extrinsic mechanical load (i.e. cyclic stretch) also induced NRVM hypertrophy, and led to down-regulation of SERCA2 and other Ca2+ transporter genes which have been associated with cardiac hypertrophy and failure in vivo. NRVM were maintained in serum-free culture medium under control conditions, or subjected to cyclic mechanical deformation (1.0 Hz, 20% maximal strain, 48 h). Under these conditions, cyclic stretch induced NRVM hypertrophy, as evidenced by significant increases in total protein/DNA ratio, myosin heavy chain (MHC) content, and atrial natriuretic factor (ANF) secretion. Cyclic stretch also induced the MHC isoenzyme "switch" which is characteristic of hemodynamic overload of the rat heart in vivo. Cyclic stretch significantly down-regulated SERCA2 and ryanodine receptor (RyR) mRNA and protein levels, while simultaneously increasing ANF mRNA. In contrast, Na+-Ca2+ exchanger and phospholamban mRNA levels were unaffected. Load-dependent SERCA2 and RyR down-regulation was independent of Ca2+ influx via voltage-gated, L-type Ca2+ channels, as cyclic stretch down-regulated SERCA2 and RyR mRNA levels in both control and verapamil-treated NRVM. These results indicate that extrinsic mechanical load (in the absence of other exogenous stimuli) induces NRVM hypertrophy and causes down-regulation of Ca2+ transporter gene expression. This in vitro model system should prove useful to dissect the intracellular signaling pathways responsible for transducing this phenotype during cardiac hypertrophy and heart failure in vivo.     

Monetization methods for evaluating investments in electricity system resilience to extreme weather and climate change

Extreme weather events and associated damages have been increasing and these trends are expected to continue. Actions are being taken to enhance electricity system resilience. However, the justification for capital investments on resilience requires utilities to justify that the economic benefits outweigh the costs. This paper reviews the types of resilience measures being analyzed in cost-benefit analyses and addresses opportunities for improvement in characterizing the benefits for investments that enhance the resilience of electricity systems.     

Using visual assessment as a foundation for greenway planning in the St. Lawrence River Valley

The growth of the ‘greenway’ as a fundamental planning concept has provided guidance for many communities locally and around the world. In the St. Lawrence River Valley, the idea is providing a common physical and cultural reference for the management of landscapes in communities along a 100 mile international corridor. Over the past 10 years, the College of Environmental Science and Forestry of the State University of New York has worked with the St. Lawrence-Eastern Ontario Commission to examine the unique visual and scenic resources of the region as the foundation for establishing a greenway tracing the St. Lawrence River. Although the idea of a greenway in the St. Lawrence River Valley is not new or unusual, the inventory and assessment of visual or scenic linear resources as a foundation is a departure from typical practice, and an experiment in defensible and rational planning. As a major summer tourism destination, the region is well aware of the critical value of its scenic resources. In our effort to identify and assess various vital resources for planning, we found an indicator in the visual nature of the landscape—both as a resource in and of itself, and as a reflection of the underlying values held by local communities for natural and cultural resources. This paper describes, as a case study, the process used to identify and assess visual and scenic resources in the region, and the use of the resulting database to initiate delineation of the proposed greenway. A discussion of the rationale and significance of the method is presented, including comments on the direction and progress in the region today.     

Home Ownership and Access to Opportunity

Home ownership and access to opportunity are foundations of the American ethos. While little research has explicitly examined a relationship between home ownership and opportunity, considerable empirical work has examined how home ownership impacts important elements of local opportunity structures as well as individual subjective perceptions of those structures. Available evidence suggests that home ownership may affect the opportunity structure by enhancing neighbourhood stability and civic involvement in local voluntary and political affairs. Home ownership may also impact perceptions of opportunity by increasing financial resources, enhancing psychological and physical health, and influencing the behaviour of youth. There is a great need for additional research that directly assesses the impacts of home ownership on local objective opportunity structures and the perception of those structures.     

Magneto-optical-trap-based, high brightness ion source for use as a nanoscale probe

We report on the demonstration of a low emittance, high brightness ion source based on magneto-optically trapped neutral atoms. Our source has ion optical properties comparable to or better than those of the commonly used liquid metal ion source. In addition, it has several advantages that offer new possibilities, including high resolution ion microscopy with ion species tailored for specific applications, contamination-free ion milling, and nanoscale implantation of a variety of elements, either in large quantities, or one at a time, deterministically. Using laser-cooled Cr atoms, we create an ion beam with a normalized rms (root-mean-square) emittance of 6.0 x 10 (-7) mm mrad M e V and approximately 0.25 pA of current, yielding a brightness as high as 2.25 A cm (-2) sr (-1) eV (-1). These values of emittance and brightness show that, with suitable ion optics, an ion beam with a useful amount of current can be produced and focused to spot sizes of less than 1 nm.     

The relation between infants' activity with objects and attention to object appearance.

The authors examined the relation between infants' motor skills and attention to objects features in events in which a hand acted on an object (e.g., squeezed it) that then produced a sound (e.g., squeaking). In this study, 6- to 7-month-old infants (N = 41) were habituated to a single event and then tested with changes in appearance and action. Infants robustly responded to changes in action, but as a group did not respond to changes in appearance. Moreover, more skilled activity with objects during naturalistic play was associated with longer looking in response to a change in appearance, but not to a change in action. Implications for the relation between perception and action in infancy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adolescents' and mothers' perceptions of the cognitive and relational functions of collaboration and adjustment in dealing with type 1 diabetes.

We examined how adolescents' and mothers' perceptions of cognitive and interpersonal functions of collaboration surrounding Type 1 diabetes differed and how they related to adolescent age, psychosocial, and diabetes adjustment. Adolescents (M = 14.16 years) and mothers completed questionnaires assessing the functions of collaboration for the adolescent, quality of the mother-adolescent relationship, emotional adjustment, and adherence to the diabetes regimen. Confirmatory factor analysis (CFA) of perceptions of collaboration confirmed three dimensions: collaboration to compensate for cognitive function, interpersonal enjoyment, and frequency of collaboration. Although adolescents' and mothers' views of interpersonal enjoyment and frequency of collaboration converged, their perceptions of compensation were unrelated. Mothers' perceptions of adolescents' compensation were unrelated to perceptions of enjoyment and frequency. Both adolescents and mothers perceived less compensation and less enjoyment of collaboration with increasing adolescent age, but only adolescents reported collaborating less frequently with higher age. Better emotional adjustment and adherence occurred when mothers and adolescents perceived enjoying collaboration (controlling for mothers' acceptance) regardless of age. Enjoying collaboration at an interpersonal level may be an important avenue for successful diabetes management during adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hope, self-efficacy, and functional recovery after knee and hip replacement surgery.

Objective: To test hypothesized relations between hope and self-efficacy for rehabilitation to depression and functional ability reported by individuals receiving joint replacement surgery. Study Design: Community-dwelling older adults (N = 100) from an orthopaedic clinic were administered measures of hope, self-efficacy for rehabilitation, pain, depression, body mass index (BDI), and mental status 1 month prior to their joint replacement surgery. These measures were completed by 62 participants 6 weeks after surgery. Demographic, health information, and functional outcome measures were obtained by medical personnel pre- and postsurgery. Main Outcome Measures: Functional outcome measures (Harris Hip and Knee Society Scores) and depressive symptomatology. Results: Hope was significantly predictive of presurgery depression, but it was not predictive of depression or functional ability after surgery. Higher levels of self-efficacy were predictive of lower postsurgery depression scores. Conclusions: Results imply that social-cognitive constructs may have utility in the prediction of emotional adjustment before and after joint surgery, but they may have limited value in anticipating functional abilities following these surgeries. Theoretical and clinical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Click" modification of silica surfaces and glass microfluidic channels

This paper demonstrates a chemical surface modification method for covalent attachment of various polymers by using silane-based "click" chemistry on silica surfaces and within glass microchannels suitable for CE systems. Modified surfaces are characterized by contact angle measurements, X-ray photoelectron spectroscopy, and Fourier transform infrared-attenuated total reflection spectroscopy. Electroosmotic flow (EOF) measurements in modified and unmodified channels are provided. Spectroscopic and transport data show that various polymers can be covalently attached to glass surfaces with a measurable change in EOF.