115 research outputs found
Quantitative Evaluation by Glucose Diffusion of Microleakage in Aged Calcium Silicate-Based Open-Sandwich Restorations
This study compared the
in vitro marginal integrity of
open-sandwich restorations based on aged calcium
silicate cement versus resin-modified glass ionomer
cement. Class II cavities were prepared on 30
extracted human third molars. These teeth were
randomly assigned to two groups (n = 10) to compare a new hydraulic calcium silicate cement
designed for restorative dentistry (Biodentine,
Septodont, Saint Maur des Fossés, France) with a
resin-modified glass ionomer cement (Ionolux, Voco,
Cuxhaven, Germany) in open-sandwich restorations
covered with a light-cured composite. Positive
(n = 5) and negative
(n = 5) controls were included. The
teeth simultaneously underwent thermocycling and
mechanocycling using a fatigue cycling machine (1,440
cycles, 5â55°C; 86,400 cycles,
50âN/cm2). The specimens were then
stored in phosphate-buffered saline to simulate aging.
After 1 year, the teeth were submitted to glucose
diffusion, and the resulting data were analyzed with a
nonparametric Mann-Whitney test. The Biodentine group
and the Ionolux group presented glucose concentrations
of 0.074 ± 0.035âg/L and 0.080 ±
0.032âg/L, respectively. No statistically
significant differences were detected between the two
groups. Therefore, the calcium silicate-based material
performs as well as the resin-modified glass ionomer
cement in open-sandwich restorations
Environmental changes and violent conflict
This letter reviews the scientific literature on whether and how environmental changes affect the risk of violent conflict. The available evidence from qualitative case studies indicates that environmental stress can contribute to violent conflict in some specific cases. Results from quantitative large-N studies, however, strongly suggest that we should be careful in drawing general conclusions. Those large-N studies that we regard as the most sophisticated ones obtain results that are not robust to alternative model specifications and, thus, have been debated. This suggests that environmental changes may, under specific circumstances, increase the risk of violent conflict, but not necessarily in a systematic way and unconditionally. Hence there is, to date, no scientific consensus on the impact of environmental changes on violent conflict. This letter also highlights the most important challenges for further research on the subject. One of the key issues is that the effects of environmental changes on violent conflict are likely to be contingent on a set of economic and political conditions that determine adaptation capacity. In the authors' view, the most important indirect effects are likely to lead from environmental changes via economic performance and migration to violent conflict. © 2012 IOP Publishing Ltd
Conflict and Livelihood Decisions in the Chittagong Hill Tracts of Bangladesh
__Abstract__
We analyse rural household livelihood and child school enrolment
decisions
in the post-conflict setting of the Chittagong Hill Tracts (CHT) region of
Bangladesh. What makes this paper innovative is the use of current subjective perceptions
regarding the possibility of violence in the future and past actual experiences
of violence in explaining household economic decision-making. Preferences
are endogenous in line with behavioural economics. Regression results show that
heightened subjective perceptions of future violence and past actual experiences
of conflict influence current consumption and child enrolment and could encourage
risky mixed crop cultivation. The trauma emanating from past experiences
combined with current high perceptions of risk of violence may induce bolder
and riskier behaviour in line with prospect theories of risk. Furthermore, a postconflic
The Impact of Climate Change on Virginia\u27s Coastal Areas
As part of HJ47/SJ47 (2020), the Virginia General Assembly directed the Joint Commission on Technology and Science (JCOTS) to study the âsafety, quality of life, and economic consequences of weather and climate-related events on coastal areas in Virginia.â In pursuit of this goal, the commission was to âaccept any scientific and technical assistance provided by the nonpartisan, volunteer Virginia Academy of Science, Engineering, and Medicine (VASEM). VASEM convened an expert study board with representation from the Office of the Governor, planning district commissions in coastal Virginia, The Port of Virginia, the Virginia Economic Development Partnership, state universities, private industry, and law firms. In producing the report, the board followed methods similar to those used by the National Academies of Science, Engineering, and Medicine by convening an expert committee tasked with studying and reporting on the topic. As a result, the report represents the views and perspectives of the study board members but was not submitted for public review or comment.
This report is the product of those efforts. It finds that climate change will have an increasingly disruptive effect on people living in Virginiaâs coastal areas during the 21st century â and that these disruptions will have repercussions across the Commonwealth. It includes an explanation of the physical forces driving climate change, an analysis of the current and projected effects of climate change on the Commonwealth, perspectives that legislators might consider as they face these challenges, and recommendations that could help Virginia implement more productive and effective strategies to address them
Effective-Range Expansion of the Neutron-Deuteron Scattering Studied by a Quark-Model Nonlocal Gaussian Potential
The S-wave effective range parameters of the neutron-deuteron (nd) scattering
are derived in the Faddeev formalism, using a nonlocal Gaussian potential based
on the quark-model baryon-baryon interaction fss2. The spin-doublet low-energy
eigenphase shift is sufficiently attractive to reproduce predictions by the
AV18 plus Urbana three-nucleon force, yielding the observed value of the
doublet scattering length and the correct differential cross sections below the
deuteron breakup threshold. This conclusion is consistent with the previous
result for the triton binding energy, which is nearly reproduced by fss2
without reinforcing it with the three-nucleon force.Comment: 21 pages, 6 figures and 6 tables, submitted to Prog. Theor. Phy
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