Doubling Up: Low Income Households Sheltering the Hidden Homeless

The costs and benefits of sheltering the homeless experienced by informal shelter providers -people who shelter their homeless friends and relatives-are investigated. The benefits of informal sheltering to the community are also examined. Informal shelter providers are among the most destitute in the community, and they are at great risk of becoming homeless themselves. The community receives considerable benefit from informal sheltering. The dependency of the community on the fragile system of informal shelter providers for prevention of homelessness indicates the inadequacy of present housing programs and the failure of our housing policies. Recommendations for preserving and nurturing the invisible but extensive system of informal shelters are made

Copper effect on the protein composition of photosystem II

The definitive version is available at: http://www.blackwell-synergy.com/doi/full/10.1111/j.1399-3054.2000.1100419.xWe provide data from in vitro experiments on the polypeptide composition, photosynthetic electron transport and oxygen evolution activity of intact photosystem II (PSII) preparations under Cu(II) toxicity conditions. Low Cu(II) concentrations (Cu(II) per PSII reaction centre unit≤230) that caused around 50% inhibition of variable chlorophyll a fluorescence and oxygen evolution activity did not affect the polypeptide composition of PSII. However, the extrinsic proteins of 33, 24 and 17 kDa of the oxygen-evolving complex of PSII were removed when samples were treated with 300 μM CuCl2 (Cu(II) per PSII reaction centre unit=1 400). The LHCII antenna complex and D1 protein of the reaction centre of PSII were not affected even at these Cu(II) concentrations. The results indicated that the initial inhibition of the PSII electron transport and oxygen-evolving activity induced by the presence of toxic Cu(II) concentrations occurred before the damage of the oxygen-evolving complex. Indeed, more than 50% inhibition could be achieved in conditions where its protein composition and integrity was apparently preserved.This work was supported by the Dirección General de Investigación Científica y Técnica (Grant PB98-1632).Peer reviewe

Two different charge-separation pathways in photosystem II

Charge separation is an essential step in the conversion of solar energy into chemical energy in photosynthesis. To investigate this process, we performed transient absorption experiments at 77 K with various excitation conditions on the isolated Photosystem II reaction center preparations from spinach. The results have been analyzed by global and target analysis and demonstrate that at least two different excited states, (Ch

The null hypothesis significance test in health sciences research (1995-2006): statistical analysis and interpretation

<p>Abstract</p> <p>Background</p> <p>The null hypothesis significance test (NHST) is the most frequently used statistical method, although its inferential validity has been widely criticized since its introduction. In 1988, the <it>International Committee of Medical Journal Editors </it>(ICMJE) warned against sole reliance on NHST to substantiate study conclusions and suggested supplementary use of confidence intervals (CI). Our objective was to evaluate the extent and quality in the use of NHST and CI, both in English and Spanish language biomedical publications between 1995 and 2006, taking into account the <it>International Committee of Medical Journal Editors </it>recommendations, with particular focus on the accuracy of the interpretation of statistical significance and the validity of conclusions.</p> <p>Methods</p> <p>Original articles published in three English and three Spanish biomedical journals in three fields (General Medicine, Clinical Specialties and Epidemiology - Public Health) were considered for this study. Papers published in 1995-1996, 2000-2001, and 2005-2006 were selected through a systematic sampling method. After excluding the purely descriptive and theoretical articles, analytic studies were evaluated for their use of NHST with P-values and/or CI for interpretation of statistical "significance" and "relevance" in study conclusions.</p> <p>Results</p> <p>Among 1,043 original papers, 874 were selected for detailed review. The exclusive use of P-values was less frequent in English language publications as well as in Public Health journals; overall such use decreased from 41% in 1995-1996 to 21% in 2005-2006. While the use of CI increased over time, the "significance fallacy" (to equate statistical and substantive significance) appeared very often, mainly in journals devoted to clinical specialties (81%). In papers originally written in English and Spanish, 15% and 10%, respectively, mentioned statistical significance in their conclusions.</p> <p>Conclusions</p> <p>Overall, results of our review show some improvements in statistical management of statistical results, but further efforts by scholars and journal editors are clearly required to move the communication toward ICMJE advices, especially in the clinical setting, which seems to be imperative among publications in Spanish.</p

Light-Induced Energetic Decoupling as a Mechanism for Phycobilisome-Related Energy Dissipation in Red Algae: A Single Molecule Study

BACKGROUND: Photosynthetic organisms have developed multiple protective mechanisms to prevent photodamage in vivo under high-light conditions. Cyanobacteria and red algae use phycobilisomes (PBsomes) as their major light-harvesting antennae complexes. The orange carotenoid protein in some cyanobacteria has been demonstrated to play roles in the photoprotective mechanism. The PBsome-itself-related energy dissipation mechanism is still unclear. METHODOLOGY/PRINCIPAL FINDINGS: Here, single-molecule spectroscopy is applied for the first time on the PBsomes of red alga Porphyridium cruentum, to detect the fluorescence emissions of phycoerythrins (PE) and PBsome core complex simultaneously, and the real-time detection could greatly characterize the fluorescence dynamics of individual PBsomes in response to intense light. CONCLUSIONS/SIGNIFICANCE: Our data revealed that strong green-light can induce the fluorescence decrease of PBsome, as well as the fluorescence increase of PE at the first stage of photobleaching. It strongly indicated an energetic decoupling occurring between PE and its neighbor. The fluorescence of PE was subsequently observed to be decreased, showing that PE was photobleached when energy transfer in the PBsomes was disrupted. In contrast, the energetic decoupling was not observed in either the PBsomes fixed with glutaraldehyde, or the mutant PBsomes lacking B-PE and remaining b-PE. It was concluded that the energetic decoupling of the PBsomes occurs at the specific association between B-PE and b-PE within the PBsome rod. Assuming that the same process occurs also at the much lower physiological light intensities, such a decoupling process is proposed to be a strategy corresponding to PBsomes to prevent photodamage of the photosynthetic reaction centers. Finally, a novel photoprotective role of gamma-subunit-containing PE in red algae was discussed

Prospect Theory in the Heterogeneous Agent Model

Using the Heterogeneous Agent Model framework, we incorporate an extension based on Prospect Theory into a popular agent-based asset pricing model. The extension covers the phenomenon of loss aversion manifested in risk aversion and asymmetric treatment of gains and losses. Using Monte Carlo methods, we investigate behavior and statistical properties of the extended model and assess its relevance with respect to financial data and stylized facts. We show that the Prospect Theory extension keeps the essential underlying mechanics of the model intact, however, that it changes the model dynamics considerably. Stability of the model increases but the occurrence of the fundamental strategy is more extreme. Moreover, the extension shifts the model closer to the behavior of real-world stock markets

Can gold be used as a hedge against the risks of Sharia-compliant securities? Application for Islamic portfolio management

In this paper, we investigate whether gold hedges Sharia-compliant stocks and Sukuk during the period from September 2005 to October 2017. The inference is taken by using both the DCC-GARCH model and the wavelet coherence analysis. On the whole, our finding suggests that gold is not effective in hedging the fluctuations of Sharia-compliant securities. However, we find that combining gold with stocks (and Sukuk) is useful in diversification and portfolio optimization. These results imply that, while gold is an excellent hedge for plain vanilla securities, it is not for Islamic exposures. This is important in light of the increasing amount of assets that are managed according to Islamic screening

Developments in the Photonic Theory of Fluorescence

Conventional fluorescence commonly arises when excited molecules relax to their ground electronic state, and most of the surplus energy dissipates in the form of photon emission. The consolidation and full development of theory based on this concept has paved the way for the discovery of several mechanistic variants that can come into play with the involvement of laser input – most notably the phenomenon of multiphoton-induced fluorescence. However, other effects can become apparent when off-resonant laser input is applied during the lifetime of the initial excited state. Examples include a recently identified scheme for laser-controlled fluorescence. Other systems of interest are those in which fluorescence is emitted from a set of two or more coupled nanoemitters. This chapter develops a quantum theoretical outlook to identify and describe these processes, leading to a discussion of potential applications ranging from all-optical switching to the generation of optical vortices

A Reliability-Generalization Study of Journal Peer Reviews: A Multilevel Meta-Analysis of Inter-Rater Reliability and Its Determinants

Background: This paper presents the first meta-analysis for the inter-rater reliability (IRR) of journal peer reviews. IRR is defined as the extent to which two or more independent reviews of the same scientific document agree. Methodology/Principal Findings: Altogether, 70 reliability coefficients (Cohen’s Kappa, intra-class correlation [ICC], and Pearson product-moment correlation [r]) from 48 studies were taken into account in the meta-analysis. The studies were based on a total of 19,443 manuscripts; on average, each study had a sample size of 311 manuscripts (minimum: 28, maximum: 1983). The results of the meta-analysis confirmed the findings of the narrative literature reviews published to date: The level of IRR (mean ICC/r 2 =.34, mean Cohen’s Kappa =.17) was low. To explain the study-to-study variation of the IRR coefficients, meta-regression analyses were calculated using seven covariates. Two covariates that emerged in the metaregression analyses as statistically significant to gain an approximate homogeneity of the intra-class correlations indicated that, firstly, the more manuscripts that a study is based on, the smaller the reported IRR coefficients are. Secondly, if the information of the rating system for reviewers was reported in a study, then this was associated with a smaller IRR coefficient than if the information was not conveyed. Conclusions/Significance: Studies that report a high level of IRR are to be considered less credible than those with a low level o