Configurational temperature control for atomic and molecular systems

A new configurational temperature thermostat suitable for molecules with holonomic constraints is derived. This thermostat has a simple set of motion equations, can generate the canonical ensemble in both position and momentum space, acts homogeneously through the spatial coordinates, and does not intrinsically violate the constraints. Our new configurational thermostat is closely related to the kinetic temperature Nosé-Hoover thermostat with feedback coupled to the position variables via a term proportional to the net molecular force. We validate the thermostat by comparing equilibrium static and dynamic quantities for a fluid of n-decane molecules under configurational and kinetic temperature control. Practical aspects concerning the implementation of the new thermostat in a molecular dynamics code and the potential applications are discussed

Outcomes of pediatric thyroidectomy: a cross-sectional evaluation

INTRODUCTION: Pediatric thyroidectomy is performed by a variety of surgical specialties. Thyroidectomy can result in a number of complications. Previous studies cite that the most common complications in children are pain and transient hypocalcemia. The purposes of this report are to assess the adverse events of thyroidectomies performed in the pediatric population and to assess the relationship between surgical specialties and postoperative thyroidectomy complications. METHODS: We conducted a cross-sectional analysis of cases from January 1, 2014 through November 1, 2015 using the National Surgical Quality Improvement Program database for patients undergoing excision of cyst or adenoma of the thyroid, unilateral thyroid lobectomy, or total thyroidectomy. RESULTS: Of the 344 patients who underwent thyroidectomy, 10 (2.9%) experienced at least one complication. The most common complications were readmission, surgical site infections, and wound disruption. There was a statistically significant association between complication incidence and surgical specialty (p=0.006). Pediatric otolaryngology had a statistically significantly higher number of complications than pediatric surgery (p<0.008). CONCLUSION: Overall, the incidence of adverse events following pediatric thyroidectomy was low

Annex 6: Changing Ocean Impacts on the Key Forage Fish Species Arctic Cod in the Western Canadian Arctic – Linking Climate Model Projections to Subsistence Fisheries

This annex highlights the results of a study focusing on the potential impacts of ocean acidification and other climate- related stressors on marine species relevant for subsistence fisheries in the Western Arctic Bioregion. The study uses a knowledge co-production approach developed in the form of a multi-step process based on a combination of modelling and analysis tools including the Scientific Method and Indigenous Traditional Knowledge (Figure A6.1). Once all steps have been completed, uncertainties can be estimated and improvements can be made either with respect to the individual steps or to the linkages between them. The process can then be repeated, including those improvements to provide a revised assessment with reduced uncertainty ranges. The steps can be summarized as follows: (1) analyze past observed trends; (2) perform projection simulations with global and regional climate models, allowing trend estimates on 20–50 year timescales; (3) assess physiological responses and thresholds in marine species via literature research, Indigenous Traditional Knowledge, observations and focused laboratory experiments; (4) add trends, climate model projections and physiological response data to species distribution / habitat suitability and higher trophic level Ecosim/ Ecopath (see Section A6.3) models; (5) assess socio-economic impacts by applying bio-economic models, evaluating current fishery-economic activities, and discussion with communities/ community representatives; and (6) review law and governance. The latter addresses adaptation measures on global, regional and national scales. This annex describes the first application of the multi-step framework in the Western Arctic Bioregion. At this point in time all the required tools have been developed, but not all components have been adequately linked. For example, while higher resolution model projections are available for the area the habitat suitability and economic models are still driven by global climate models, the Ecopath model (see Section on The Beaufort Sea food web model) has not yet been run into the future and physiological responses are reflected in the higher trophic level models to a limited extent, if at all. In addition, while collaboration with local communities has been established (see Section on Community interests), Indigenous Traditional Knowledge has been included to a very limited extent. To summarize, this case study provides an assessment that includes all required tools, but limited linkages. It has a strong focus on uncertainty analyses and the identification of gaps in knowledge. Particular emphasis is given to the key forage fish species Arctic cod (Boreogadus saida), since climate model projections can be linked more directly to key forage species than to the (mostly) higher trophic level species harvested

Predicting non-native insect impact: focusing on the trees to see the forest

Non-native organisms have invaded novel ecosystems for centuries, yet we have only a limited understanding of why their impacts vary widely from minor to severe. Predicting the impact of non-established or newly detected species could help focus biosecurity measures on species with the highest potential to cause widespread damage. However, predictive models require an understanding of potential drivers of impact and the appropriate level at which these drivers should be evaluated. Here, we used non-native, specialist herbivorous insects of forest ecosystems to test which factors drive impact and if there were differences based on whether they used woody angiosperms or conifers as hosts. We identified convergent and divergent patterns between the two host types indicating fundamental similarities and differences in their interactions with non-native insects. Evolutionary divergence time between native and novel hosts was a significant driver of insect impact for both host types but was modulated by different factors in the two systems. Beetles in the subfamily Scolytinae posed the highest risk to woody angiosperms, and different host traits influenced impact of specialists on conifers and woody angiosperms. Tree wood density was a significant predictor of host impact for woody angiosperms with intermediate densities (0.5–0.6 mg/mm3) associated with highest risk, whereas risk of impact was highest for conifers that coupled shade tolerance with drought intolerance. These results underscore the importance of identifying the relevant levels of biological organization and ecological interactions needed to develop accurate risk models for species that may arrive in novel ecosystems

Impacts of the Changing Ocean-Sea Ice System on the Key Forage Fish Arctic Cod (Boreogadus Saida) and Subsistence Fisheries in the Western Canadian Arctic—Evaluating Linked Climate, Ecosystem and Economic (CEE) Models

This study synthesizes results from observations, laboratory experiments and models to showcase how the integration of scientific methods and indigenous knowledge can improve our understanding of (a) past and projected changes in environmental conditions and marine species; (b) their effects on social and ecological systems in the respective communities; and (c) support management and planning tools for climate change adaptation and mitigation. The study links climate-ecosystem-economic (CEE) models and discusses uncertainties within those tools. The example focuses on the key forage species in the Inuvialuit Settlement Region (Western Canadian Arctic), i.e., Arctic cod (Boreogadus saida). Arctic cod can be trophically linked to sea-ice algae and pelagic primary producers and are key vectors for energy transfers from plankton to higher trophic levels (e.g., ringed seals, beluga), which are harvested by Inuit peoples. Fundamental changes in ice and ocean conditions in the region affect the marine ecosystem and fish habitat. Model simulations suggest increasing trends in oceanic phytoplankton and sea-ice algae with high interannual variability. The latter might be linked to interannual variations in Arctic cod abundance and mask trends in observations. CEE simulations incorporating physiological temperature limits data for the distribution of Arctic cod, result in an estimated 17% decrease in Arctic cod populations by the end of the century (high emission scenario), but suggest increases in abundance for other Arctic and sub-Arctic species. The Arctic cod decrease is largely caused by increased temperatures and constraints in northward migration, and could directly impact key subsistence species. Responses to acidification are still highly uncertain, but sensitivity simulations suggests an additional 1% decrease in Arctic cod populations due to pH impacts on growth and survival. Uncertainties remain with respect to detailed future changes, but general results are likely correct and in line with results from other approaches. To reduce uncertainties, higher resolution models with improved parameterizations and better understanding of the species' physiological limits are required. Arctic communities should be directly involved, receive tools and training to conduct local, unified research and food chain monitoring while decisions regarding commercial fisheries will need to be precautionary and adaptive in light of the existing uncertainties

Genetic risk variants associated with in situ breast cancer

INTRODUCTION: Breast cancer in situ (BCIS) diagnoses, a precursor lesion for invasive breast cancer, comprise about 20 % of all breast cancers (BC) in countries with screening programs. Family history of BC is considered one of the strongest risk factors for BCIS. METHODS: To evaluate the association of BC susceptibility loci with BCIS risk, we genotyped 39 single nucleotide polymorphisms (SNPs), associated with risk of invasive BC, in 1317 BCIS cases, 10,645 invasive BC cases, and 14,006 healthy controls in the National Cancer Institute's Breast and Prostate Cancer Cohort Consortium (BPC3). Using unconditional logistic regression models adjusted for age and study, we estimated the association of SNPs with BCIS using two different comparison groups: healthy controls and invasive BC subjects to investigate whether BCIS and BC share a common genetic profile. RESULTS: We found that five SNPs (CDKN2BAS-rs1011970, FGFR2-rs3750817, FGFR2-rs2981582, TNRC9-rs3803662, 5p12-rs10941679) were significantly associated with BCIS risk (P value adjusted for multiple comparisons &lt;0.0016). Comparing invasive BC and BCIS, the largest difference was for CDKN2BAS-rs1011970, which showed a positive association with BCIS (OR = 1.24, 95 % CI: 1.11-1.38, P = 1.27 x 10(-4)) and no association with invasive BC (OR = 1.03, 95 % CI: 0.99-1.07, P = 0.06), with a P value for case-case comparison of 0.006. Subgroup analyses investigating associations with ductal carcinoma in situ (DCIS) found similar associations, albeit less significant (OR = 1.25, 95 % CI: 1.09-1.42, P = 1.07 x 10(-3)). Additional risk analyses showed significant associations with invasive disease at the 0.05 level for 28 of the alleles and the OR estimates were consistent with those reported by other studies. CONCLUSIONS: Our study adds to the knowledge that several of the known BC susceptibility loci are risk factors for both BCIS and invasive BC, with the possible exception of rs1011970, a putatively functional SNP situated in the CDKN2BAS gene that may be a specific BCIS susceptibility locus