Does Advice Help to Prove Propositional Tautologies?

One of the starting points of propositional proof complexity is the seminal paper by Cook and Reckhow [6], where they defined propositional proof systems as poly-time computable functions which have all propositional tautologies as their range. Motivated by provability consequences in bounded arithmetic, Cook and Krajíček [5] have recently started the investigation of proof systems which are computed by poly-time functions using advice. While this yields a more powerful model, it is also less directly applicable in practice. In this note we investigate the question whether the usage of advice in propositional proof systems can be simplified or even eliminated. While in principle, the advice can be very complex, we show that proof systems with logarithmic advice are also computable in poly-time with access to a sparse NP-oracle. In addition, we show that if advice is ”not very helpful” for proving tautologies, then there exists an optimal propositional proof system without advice. In our main result, we prove that advice can be transferred from the proof to the formula, leading to an easier computational model. We obtain this result by employing a recent technique by Buhrman and Hitchcock [4]

Loneliness and life satisfaction amongst three cultural groups

Abstract Studies into loneliness and life satisfaction have rarely assessed the role of culture in moderating the relationship between these variables. The present study examined the relationship between loneliness and life satisfaction using data from three nonstudent samples collected from Italian, Anglo-Canadian and Chinese-Canadian populations. A total of 206 respondents completed the Revised UCLA Loneliness Scale (Russell, Peplau, & Cutrona, 1980) and the Satisfaction with Life Scale (Diener, Emmons, Larsen, & Griffin, 1985). Two contrasting hypotheses were compared: one, a “postmodern” hypothesis, predicting that the relationship between life satisfaction and loneliness would be stronger in our individualist sample of Anglo-Canadians, and a second, “relational” hypothesis predicting this association to be strongest in our collectivist, Chinese-Canadian sample. Our findings demonstrated that culture has a small but significant impact on the relationship between loneliness and life satisfaction, and, consistent with the relational hypothesis, the relationship between the two concepts was strongest among our Chinese-Canadian respondents and weakest among our Anglo-Canadian participants This finding is discussed in the context of the strong expectations of social cohesion in collectivist societies

Supported Employment: A Best Practice for People with Psychiatric Disabilities

Over the past several decades, research from a variety of fields has presented powerful evidence of the importance of employment to people with psychiatric disabilities. Many of these people want to work and can successfully participate in the labor market in a variety of competitive jobs. Researchers have also shown how employment can alleviate poverty, reduce hospitalization, and improve quality of life. Society also benefits through taxes paid by workers, goods and services they purchase, and reductions in entitlements and the overall cost of care. However, the 1997 National Health Interview Survey (NHIS) reports employment rates for people with a wide range of mental disorders to be 37.1 percent (Harris et al., 2005; New Freedom Commission on Mental Health, 2003). Employment rates for people with schizophrenia and related disorders are 22 percent (Jans, et al., 2004). Recently, funding agencies and practitioners have begun to move towards evidence-based practice in serving people with psychiatric disabilities. A number of reviews and meta-analyses of single-site, randomized controlled trials of supported employment for this group have found it to be more effective at establishing competitive employment outcomes than prevocational training or non-vocational community care (Crowther et al., 2001; Twamley et al., 2003; Wewiorski & Fabian, 2004). Still in question at the time of this study\u27s funding, however, was the effectiveness of different models of supported employment, operating in a variety of organizational settings, for consumers with diverse demographic characteristics, in different regions of the country. Therefore, the Employment Intervention Demonstration Program (EIDP) was designed as a multi-site randomized controlled trial of the effectiveness of supported employment (SE) for people with psychiatric disabilities in eight locations across the U.S. SE programs use a rapid job search approach to help clients obtain jobs directly (rather than providing lengthy assessment, training, and counseling), and provide them with ongoing support to maintain and improve their earnings after they start work. This policy brief describes the EIDP, presents study findings, and suggests some policy and research implications

Zero gravity tissue-culture laboratory

Hardware was developed for performing experiments to detect the effects that zero gravity may have on living human cells. The hardware is composed of a timelapse camera that photographs the activity of cell specimens and an experiment module in which a variety of living-cell experiments can be performed using interchangeable modules. The experiment is scheduled for the first manned Skylab mission

Aquatic Nitrate Retention at River Network Scales Across Flow Conditions Determined Using Nested In Situ Sensors

Nonpoint pollution sources are strongly influenced by hydrology and are therefore sensitive to climate variability. Some pollutants entering aquatic ecosystems, e.g., nitrate, can be mitigated by in‐stream processes during transport through river networks. Whole river network nitrate retention is difficult to quantify with observations. High frequency, in situ nitrate sensors, deployed in nested locations within a single watershed, can improve estimates of both nonpoint inputs and aquatic retention at river network scales. We deployed a nested sensor network and associated sampling in the urbanizing Oyster River watershed in coastal New Hampshire, USA, to quantify storm event‐scale loading and retention at network scales. An end member analysis used the relative behavior of reactive nitrate and conservative chloride to infer river network fate of nitrate. In the headwater catchments, nitrate and chloride concentrations are both increasingly diluted with increasing storm size. At the mouth of the watershed, chloride is also diluted, but nitrate tended to increase. The end member analysis suggests that this pattern is the result of high retention during small storms (51–78%) that declines to zero during large storms. Although high frequency nitrate sensors did not alter estimates of fluxes over seasonal time periods compared to less frequent grab sampling, they provide the ability to estimate nitrate flux versus storm size at event scales that is critical for such analyses. Nested sensor networks can improve understanding of the controls of both loading and network scale retention, and therefore also improve management of nonpoint source pollution

Lower Scotts Creek Floodplain and Habitat Enhancement Project

Scotts Creek, located in northern Santa Cruz County, maintains the southernmost persistent population of Central California Coast (CCC) Coho Salmon (endangered) in addition to CCC steelhead (threatened). Fisheries biologists believe overwinter mortality due to lack of refuge habitat is the primary factor limiting salmonid production. Instream rearing habitat may also be limiting, especially during drought years. The legacy effects of historic land use practices, including dredging, wood removal, and the construction of levees, continued to limit refuge and rearing opportunities. A restoration project was implemented to improve refuge and rearing opportunities for salmonids along lower Scotts Creek by removing portions of the deteriorating levee, grading new connections with existing off-channel features, enhancing tributary confluences, constructing alcove habitat features at the margins of the stream channel, and constructing large wood complexes (LWCs) instream. Novel restoration techniques were employed on an experimental basis. Whole in-situ alder trees were pushed into the stream channel with their root systems left partially intact to establish living key pieces. Individual log, boulder, and rootwad LWC components were attached together with couplers that permitted some freedom of independent movement among the individual components. LWCs were braced against live, standing trees and stabilized with boulder ballasts placed on the streambed, which eliminated excavation of the streambed/banks and the need to dewater or divert the stream during construction. Project performance, changes to physical habitat characteristics, and changes to stream morphology associated with implementation were monitored using habitat assessment methods derived from the California Department of Fish and Wildlife’s (CDFW) salmonid habitat survey protocol (Flosi et al. 2010), and topographic survey techniques and data analysis adapted from Columbia Habitat Monitoring Protocol (Bouwes et al. 2011). Preliminary results indicated that LWCs remained stable and functional. In addition, implementation of the restoration project increased pool frequency, low-flow pool volume, instream cover, frequency of instream, alcove, and off-channel refuge habitat features, and frequency of points of connectivity with the floodplain. Long-term monitoring will be required to determine the survivorship, decay rates, and overall persistence of alder recruits

Types and Synonyms

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Are Any Species Uniform?

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Rumen motility, tissue and fluid concentrations of aflatoxins B₁ and M₁ and clinical and pathologic changes in acute bovine aflatoxicosis

http://www.worldcat.org/oclc/1309034