3,770 research outputs found
Lewisian quidditism, humility, and diffidence
In ‘Ramseyan Humility’ Lewis presents the Permutation Argument for quidditism. As he presents it the argument is simple enough, but once one digs beneath its surface, and attempts to understand it in strictly Lewisian terms, difficulties arise. The fundamental difficulty is that, as he presents it, the argument only seems to be sound if one rejects views that Lewis explicitly holds. One aim of this paper is to clarify the argument to show that one can make sense of it in strictly Lewisian terms. In so doing I clarify Lewis’s view, clearly lay out the commitments that Lewis has, and define quidditism in strictly Lewisian terms. However, I also have a secondary aim. Lewis accepts that quidditism entails a form of scepticism, that he calls ‘Humility’. However, by an extension of the permutation argument I show that quidditism entails a form of scepticism, that I call ‘Diffidence’, that is far more wide-reaching than Humility
Structure and Vibrations of the Vicinal Copper (211) Surface
We report a first principles theoretical study of the surface relaxation and
lattice dynamics of the Cu(211) surface using the plane wave pseudopotential
method. We find large atomic relaxations for the first several atomic layers
near the step edges on this surface, and a substantial step-induced
renormalization of the surface harmonic force constants. We use the results to
study the harmonic fluctuations around the equilibrium structure and find three
new step-derived features in the zone center vibrational spectrum. Comparison
of these results with previous theoretical work and weith experimental studies
using inelastic He scattering are reported.Comment: 6 Pages RevTex, 7 Figures in Postscrip
Antibacterial Activity of Partially Oxidized Ag/Au Nanoparticles against the Oral Pathogen Porphyromonas gingivalis
Advances in nanotechnology provide opportunities for the prevention and treatment of periodontal disease. While physicochemical properties of Ag containing nanoparticles (NPs) are known to influence the magnitude of their toxicity, it is thought that nanosilver can be made less toxic to eukaryotes by passivation of the NPs with a benign metal. Moreover, the addition of other noble metals to silver nanoparticles, in the alloy formulation, is known to alter the silver dissolution behavior. Thus, we synthesized glutathione capped Ag/Au alloy bimetallic nanoparticles (NPs) via the galvanic replacement reaction between maltose coated Ag NPs and chloroauric acid (HAuCl4) in 5% aqueous triblock F127 copolymer solution. We then compared the antibacterial activity of the Ag/Au NPs to pure Ag NPs on Porphyromonas gingivalis W83, a key pathogen in the development of periodontal disease. Only partially oxidized glutathione capped Ag and Ag/Au (Au : Ag ≈ 0.2) NPs inhibited the planktonic growth of P. gingivalis W83. This effect was enhanced in the presence of hydrogen peroxide, which simulates the oxidative stress environment in the periodontal pocket during chronic inflammation
Cs7Sm11[TeO3]12Cl16 and Rb7Nd11[TeO3]12Br16, the new tellurite halides of the tetragonal Rb6LiNd11[SeO3]12Cl16 structure type
The authors thank the Russian Foundation for Basic Researches for the support of this work under Grants No. 14-03-00604_a and 12-03-92604-KO_a. The X-ray study of compound II was made possible due to M.V. Lomonosov Moscow State University Programm of Development. PL thanks the University of St Andrews and EPSRC for DTA Studentships to CB and LJD.Two new rare-earth – alkali – tellurium oxide halides were synthesized by a salt flux technique and characterized by single-crystal X-ray diffraction. The structures of the new compounds Cs7Sm11[TeO3]12Cl16 (I) and Rb7Nd11[TeO3]12Br16 (II) (both tetragonal, space group I4/mcm) correspond to the sequence of [MLn11(TeO3)12] and [M6×16] layers and bear very strong similarities to those of known selenite analogs. We discuss the trends in similarities and differences in compositions and structural details between the Se and Te compounds; more members of the family are predicted.PostprintPeer reviewe
Report of the Topical Group on Micro-Pattern Gaseous Detectors for Snowmass 2021
This report summarizes white papers on micro-pattern gaseous detectors
(MPGDs) that were submitted to the Instrumentation Frontier Topical Group IF05,
as part of the Snowmass 2021 decadal survey of particle physics.Comment: contribution to Snowmass 202
Low dietary intake of magnesium is associated with increased externalising behaviours in adolescents
Objective: Adequate Zn and Mg intakes may be beneficial for the prevention and treatment of mental health problems, such as depression, anxiety and attention-deficit hyperactivity disorder. We aimed to investigate the prospective association between dietary intakes of Zn and Mg and internalising and externalising behaviour problems in a population-based cohort of adolescents. Design: Prospective analysis (general linear mixed models) of dietary intakes of Zn and Mg assessed using a validated FFQ and mental health symptoms assessed using the Youth Self-Report (YSR), adjusting for sex, physical activity, family income, supplement status, dietary misreporting, BMI, family functioning and energy intake. Setting: Western Australian Pregnancy Cohort (Raine) Study. Subjects: Adolescents (n 684) at the 14- and 17-year follow-ups. Results: Higher dietary intake of Mg (per SD increase) was significantly associated with reduced externalising behaviours (β=−1·45; 95 % CI −2·40, −0·50; P=0·003). There was a trend towards reduced externalising behaviours with higher Zn intake (per SD increase; β=−0·73; 95 % CI −1·57, 0·10; P=0·085).Randomised controlled trials are necessary to determine any benefit of micronutrient supplementation in the prevention and treatment of mental health problems in adolescents.The study shows an association between higher dietary Mg intake and reduced externalising behaviour problems in adolescents. We observed a similar trend, although not statistically significant, for Zn intake. Randomised controlled trials are necessary to determine any benefit of micronutrient supplementation in the prevention and treatment of mental health problems in adolescents
Mood instability, mental illness and suicidal ideas : results from a household survey
Purpose:
There is weak and inconsistent evidence that mood instability (MI) is associated with depression, post traumatic stress disorder (PTSD) and suicidality although the basis of this is unclear. Our objectives were first to test whether there is an association between depression and PTSD, and MI and secondly whether MI exerts an independent effect on suicidal thinking over and above that explained by common mental disorders.
Methods:
We used data from the Adult Psychiatric Morbidity Survey 2007 (N = 7,131). Chi-square tests were used to examine associations between depression and PTSD, and MI, followed by regression modelling to examine associations between MI and depression, and with PTSD. Multiple logistic regression analyses were used to assess the independent effect of MI on suicidal thinking, after adjustment for demographic factors and the effects of common mental disorder diagnoses.
Results:
There are high rates of MI in depression and PTSD and the presence of MI increases the odds of depression by 10.66 [95 % confidence interval (CI) 7.51–15.13] and PTSD by 8.69 (95 % CI 5.90–12.79), respectively, after adjusting for other factors. Mood instability independently explained suicidal thinking, multiplying the odds by nearly five (odds ratio 4.82; 95 % CI 3.39–6.85), and was individually by some way the most important single factor in explaining suicidal thoughts.
Conclusions:
MI is strongly associated with depression and PTSD. In people with common mental disorders MI is clinically significant as it acts as an additional factor exacerbating the risk of suicidal thinking. It is important to enquire about MI as part of clinical assessment and treatment studies are required
A Controlled Study of Funding for Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome as Resource Capacity Building in the Health System in Rwanda
Because human inmmunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) receives more donor funding globally than that for all other diseases combined, some critics allege this support undermines general health care. This empirical study evaluates the impact of HIV/AIDS funding on the primary health care system in Rwanda. Using a quasi-experimental design, we randomly selected 25 rural health centers (HCs) that started comprehensive HIV/AIDS services from 2002 through 2006 as the intervention group. Matched HCs with no HIV/AIDS services formed the control group. The analysis compared growth in inputs and services between intervention and control HCs with a difference-in-difference analysis in a random-effects model. Intervention HCs performed better than control HCs in most services (seven of nine), although only one of these improvements (Bacille Calmette-Guérin vaccination) reached or approached statistical significance. In conclusion, this six-year controlled study found no adverse effects of the expansion of HIV/AIDS services on non-HIV services among rural health centers in Rwanda
Collaborative review of pilot projects to inform policy: A methodological remedy for pilotitis?
BACKGROUND
In rural health and other health service development contexts, there is frustration with a reliance on pilot projects as a means of informing policy and service innovation. There is also an emerging recognition that existing research methods do not draw lessons from the failed sustainability that characterises many of these pilots and demonstration projects.
DISCUSSION:
This article describes critical aspects of the methodology of a successful collaborative, multi-method, systematic synthesis of exemplary primary health care pilot projects in rural and remote Australia, which synthesised principles from a number of pilot projects to inform policy makers and planners. Hallmarks of the method were: the nature of the source materials for the research, the subsequent research engagement with the actual pilot projects, the extent of collaboration throughout the study with end-users from policy and planning arenas, and the attention to procedural quality.
SUMMARY:
The methodology, while time consuming, has resulted in applied, policy-relevant findings, and evidence of consideration by policy-makers
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