Roadless and Low-Traffic Areas as Conservation Targets in Europe

With increasing road encroachment, habitat fragmentation by transport infrastructures has been a serious threat for European biodiversity. Areas with no roads or little traffic (“roadless and low-traffic areas”) represent relatively undisturbed natural habitats and functioning ecosystems. They provide many benefits for biodiversity and human societies (e.g., landscape connectivity, barrier against pests and invasions, ecosystem services). Roadless and low-traffic areas, with a lower level of anthropogenic disturbances, are of special relevance in Europe because of their rarity and, in the context of climate change, because of their contribution to higher resilience and buffering capacity within landscape ecosystems. An analysis of European legal instruments illustrates that, although most laws aimed at protecting targets which are inherent to fragmentation, like connectivity, ecosystem processes or integrity, roadless areas are widely neglected as a legal target. A case study in Germany underlines this finding. Although the Natura 2000 network covers a significant proportion of the country (16%), Natura 2000 sites are highly fragmented and most low-traffic areas (75%) lie unprotected outside this network. This proportion is even higher for the old Federal States (western Germany), where only 20% of the low-traffic areas are protected. We propose that the few remaining roadless and low-traffic areas in Europe should be an important focus of conservation efforts; they should be urgently inventoried, included more explicitly in the law and accounted for in transport and urban planning. Considering them as complementary conservation targets would represent a concrete step towards the strengthening and adaptation of the Natura 2000 network to climate change

Development of design and simulation model and safety study of large-scale hydrogen production using nuclear power.

Before this LDRD research, no single tool could simulate a very high temperature reactor (VHTR) that is coupled to a secondary system and the sulfur iodine (SI) thermochemistry. Furthermore, the SI chemistry could only be modeled in steady state, typically via flow sheets. Additionally, the MELCOR nuclear reactor analysis code was suitable only for the modeling of light water reactors, not gas-cooled reactors. We extended MELCOR in order to address the above deficiencies. In particular, we developed three VHTR input models, added generalized, modular secondary system components, developed reactor point kinetics, included transient thermochemistry for the most important cycles [SI and the Westinghouse hybrid sulfur], and developed an interactive graphical user interface for full plant visualization. The new tool is called MELCOR-H2, and it allows users to maximize hydrogen and electrical production, as well as enhance overall plant safety. We conducted validation and verification studies on the key models, and showed that the MELCOR-H2 results typically compared to within less than 5% from experimental data, code-to-code comparisons, and/or analytical solutions

Risk factors for complications after cholecystectomy for common bile duct stones: An EAST multicenter study

We sought to prospectively identify risk factors for biliary complications and 30-day readmission after cholecystectomy for choledocholithiasis and gallstone pancreatitis across multiple US hospitals. We performed a prospective, observational study of patients who underwent same admission cholecystectomy for choledocholithiasis and gallstone pancreatitis between 2016 and 2019 at 12 US centers. Patients with prior history of endoscopic retrograde cholangiopancreatography or diagnosis of cholangitis were excluded. We used logistic regression to determine associations between preoperative demographics, labs, and imaging on primary outcomes: postoperative biliary complications and 30-day readmission. There were 989 patients in the cohort. There were 16 (1.6%) patients with postoperative biliary complications, including intra-abdominal abscesses, endoscopic retrograde cholangiopancreatography-induced pancreatitis, and biliary leaks. Increasing operative time (odds ratio 1.01, 95% confidence interval 1.00-1.01, P = .02), worsening leukocytosis (odds ratio 1.16, 95% confidence interval 1.07-1.25, P = .0002), and jaundice (odds ratio 3.25, 95% confidence interval 1.01-10.42, P = .04) were associated with postoperative biliary complications. There were 36 (3.6%) patients readmitted within 30 days owing to a surgical complication. A prior postoperative biliary complication (odds ratio 7.8, 95% confidence interval 1.63-37.27, P = .01), male sex (odds ratio 2.42, 95% confidence interval 1.2-4.87, P = .01), and index operative duration (odds ratio 1.01, 95% confidence interval 1.00-1.01, P = .03) were associated with 30-day readmission. Among patients undergoing cholecystectomy for common bile duct stones, jaundice, worsening leukocytosis, and longer operations are associated with postoperative biliary complications. A prior biliary complication is also predictive of a 30-day readmission. Surgeons should recognize these factors and avoid prematurely discharging at-risk patients given their propensity to develop complications and require readmission