823 research outputs found
Biodegradation of BTEX in a fungal biofilter: Influence of operational parameters, effect of shock-loads and substrate stratification
The effect of relative humidity (RH: 30% to >95%) of a gas-phase mixture composed of benzene, toluene, ethylbenzene and para-, meta- and ortho-xylenes (BTEX), inlet concentrations (0.2–12.6 g m−3), and empty bed residence times (EBRTs) (48–144 s) was tested in a fungi-dominant biofilter. A maximum elimination capacity (ECmax) of 244.2 gBTEX m−3 h−1 was achieved at a total inlet loading rate (ILRT) of 371.2 gBTEX m−3 h−1 (RH: 65%). The transient-state response was tested by increasing the ILRT, in two steps, from ∼50 to 850 g m−3 h−1 and from ∼50 to 320 g m−3 h−1, at a constant EBRT of 41.7 s. Increasing the ILRT reduced the total BTEX removal efficiency (RET) from >97% to 35%, and from >90% to 60% during medium and high shock-load, respectively. When subjected to short (4 d) and long-term (7 d) shut-down periods, the biofilter was able to recover high ECmax of, respectively, 200 and 72 gBTEX m−3 h−1 after resuming operation.Ministerio de Educación y Ciencia; CTM2004-00427/TECNOMinisterio de Educación y Ciencia; SB-2004-0135Ministerio de Ciencia e Innovación; JCI-2008-038
Surface morphology modifications of human teeth induced by a picosecond Nd:YAG laser operating at 532 nm
AbstractThe interaction of an Nd:YAG laser, operating at 532 nm with 40 ps pulse duration, with human teeth was studied. The results show that teeth were significantly modified at an energy fluence of about 11 J/cm2. Various surface morphologies of enamel and dentine were recorded. Features on enamel include crater (conical form) in the central part and cauliflower morphology at the periphery, whereas on dentine the crater looks like a stretched dome between sharp edges. The behavior of the enamel-dentine junction area showed different morphology with respect to both tooth enamel and dentine alone. Finally, the junction channel showed a removal of collagen fibers and the formation of a needle-like bottom structure. Generally, this investigation showed that the picosecond Nd:YAG laser can ablate a tooth surface practically instantaneously, implying that large tooth surfaces can be processed in short time
Perceived psychosocial impacts of legalized same-sex marriage: A scoping review of sexual minority adults’ experiences
A growing body of literature provides important insights into the meaning and impact of the right to marry a same-sex partner among sexual minority people. We conducted a scoping review to 1) identify and describe the psychosocial impacts of equal marriage rights among sexual minority adults, and 2) explore sexual minority women (SMW) perceptions of equal marriage rights and whether psychosocial impacts differ by sex. Using Arksey and O’Malley’s framework we reviewed peer-reviewed English-language publications from 2000 through 2019. We searched six databases (PubMed, PsycINFO, CINAHL, Web of Science, JSTOR, and Sociological Abstracts) to identify English language, peer-reviewed journal articles reporting findings from empirical studies with an explicit focus on the experiences and perceived impact of equal marriage rights among sexual minority adults. We found 59 studies that met our inclusion criteria. Studies identified positive psychosocial impacts of same-sex marriage (e.g., increased social acceptance, reduced stigma) across individual, interpersonal (dyad, family), community (sexual minority), and broader societal levels. Studies also found that, despite equal marriage rights, sexual minority stigma persists across these levels. Only a few studies examined differences by sex, and findings were mixed. Research to date has several limitations; for example, it disproportionately represents samples from the U.S. and White populations, and rarely examines differences by sexual or gender identity or other demographic characteristics. There is a need for additional research on the impact of equal marriage rights and same-sex marriage on the health and well-being of diverse sexual minorities across the globe
Overshadowing by fixed- and variable-duration stimuli
Two experiments investigated the effect of the temporal distribution form of a stimulus on its ability to produce an overshadowing effect. The overshadowing stimuli were either of the same duration on every trial, or of a variable duration drawn from an exponential distribution with the same mean duration as that of the fixed stimulus. Both experiments provided evidence that a variable-duration stimulus was less effective than a fixed-duration cue at overshadowing conditioning to a target conditioned stimulus (CS); moreover, this effect was independent of whether the overshadowed CS was fixed or variable. The findings presented here are consistent with the idea that the strength of the association between CS and unconditioned stimulus (US) is, in part, determined by the temporal distribution form of the CS. These results are discussed in terms of time-accumulation and trial-based theories of conditioning and timing
Women’s health and well-being in low-income formal and informal neighbourhoods on the eve of the armed conflict in Aleppo
Objectives
To explore how married women living in low-income formal and informal neighbourhoods in Aleppo, Syria, perceived the effects of neighbourhood on their health and well-being, and the relevance of these findings to future urban rebuilding policies post-conflict.
Methods
Semi-structured interviews were undertaken with eighteen married women living in informal or socioeconomically disadvantaged formal neighbourhoods in Aleppo in 2011, a year before the armed conflict caused massive destruction in all these neighbourhoods.
Results
Our findings suggest that the experience of neighbourhood social characteristics is even more critical to women’s sense of well-being than environmental conditions and physical infrastructure. Most prominent was the positive influence of social support on well-being.
Conclusions
The significance of this study lies, first, in its timing, before the widespread destruction of both formal and informal neighbourhoods in Aleppo and, second, and in its indication of the views of women who lived in marginalised communities on what neighbourhood characteristics mattered to them. Further research post-conflict needs to explore how decisions on urban rebuilding are made and their likely influence on health and well-being
The Influence of a Firms\u27 Business Strategy on the Downside Risk of Earnings, Accruals and Cash Flow
This study examines whether a firm\u27s business strategy is an underlying determinant of downside risk in accounting earnings and its components. Based on organizational theory we predict that firms following an innovative prospector strategy exhibit lower profitability tendencies than firms following a cost-oriented defender strategy. Further, we anticipate that these strategies are asymmetrically positioned towards environmental uncertainty, with defenders focusing their efforts to efficiency, cost control, and minimizing exposure to downside risk, whereas prospectors direct their resources to flexibility, innovation, and maximizing the growth potential through aggressive expansion to new product markets. We find that prospectors are indeed less profitable than defenders. We also demonstrate that prospectors have greater total and downside earnings risk. Finally, we decompose earnings into accruals and cash flow and show that the higher exposure of prospectors to earnings downside risk is driven by the cash flow component rather than the accrual component. Collectively, our results suggest that considering how strategy interacts with financial reporting attributes is a useful way for evaluating a firms\u27 risk profile
Improvement of Cardiac Function in Mouse Myocardial Infarction after Transplantation of Epigenetically-Modified Bone Marrow Progenitor Cells
OBJECTIVE: To study usefulness of bone marrow progenitor cells (BPCs) epigenetically altered by chromatin modifying agents in mediating heart repair after myocardial infarction in mice. METHODS AND RESULTS: We tested the therapeutic efficacy of bone marrow progenitor cells treated with the clinically-used chromatin modifying agents Trichostatin A (TSA, histone deacetylase inhibitor) and 5Aza-2-deoxycytidine (Aza, DNA methylation inhibitor) in a mouse model of acute myocardial infarction (AMI). Treatment of BPCs with Aza and TSA induced expression of pluripotent genes Oct4, Nanog, Sox2, and thereafter culturing these cells in defined cardiac myocyte-conditioned medium resulted in their differentiation into cardiomyocyte progenitors and subsequently into cardiac myocytes. Their transition was deduced by expression of repertoire of markers: Nkx2.5, GATA4, cardiotroponin T, cardiotroponin I, α-sarcomeric actinin, Mef2c and MHC-α. We observed that the modified BPCs had greater AceH3K9 expression and reduced histone deacetylase1 (HDAC1) and lysine-specific demethylase1 (LSD1) expression compared to untreated BPCs, characteristic of epigenetic changes. Intra-myocardial injection of modified BPCs after AMI in mice significantly improved left ventricular function. These changes were ascribed to differentiation of the injected cells into cardiomyocytes and endothelial cells. CONCLUSION: Treatment of BPCs with Aza and TSA converts BPCs into multipotent cells, which can then be differentiated into myocyte progenitors. Transplantation of these modified progenitor cells into infarcted mouse hearts improved left ventricular function secondary to differentiation of cells in the niche into myocytes and endothelial cells
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