Assessing Bottlenecks in Vertically Organized Beef Systems

Agribusiness,

Optimization of supply diversity for the self-assembly of simple objects in two and three dimensions

The field of algorithmic self-assembly is concerned with the design and analysis of self-assembly systems from a computational perspective, that is, from the perspective of mathematical problems whose study may give insight into the natural processes through which elementary objects self-assemble into more complex ones. One of the main problems of algorithmic self-assembly is the minimum tile set problem (MTSP), which asks for a collection of types of elementary objects (called tiles) to be found for the self-assembly of an object having a pre-established shape. Such a collection is to be as concise as possible, thus minimizing supply diversity, while satisfying a set of stringent constraints having to do with the termination and other properties of the self-assembly process from its tile types. We present a study of what we think is the first practical approach to MTSP. Our study starts with the introduction of an evolutionary heuristic to tackle MTSP and includes results from extensive experimentation with the heuristic on the self-assembly of simple objects in two and three dimensions. The heuristic we introduce combines classic elements from the field of evolutionary computation with a problem-specific variant of Pareto dominance into a multi-objective approach to MTSP.Comment: Minor typos correcte

The influence of soil communities on the temperature sensitivity of soil respiration

Soil respiration represents a major carbon flux between terrestrial ecosystems and the atmosphere, and is expected to accelerate under climate warming. Despite its importance in climate change forecasts, however, our understanding of the effects of temperature on soil respiration (RS) is incomplete. Using a metabolic ecology approach we link soil biota metabolism, community composition and heterotrophic activity, to predict RS rates across five biomes. We find that accounting for the ecological mechanisms underpinning decomposition processes predicts climatological RS variations observed in an independent dataset (n = 312). The importance of community composition is evident because without it RS is substantially underestimated. With increasing temperature, we predict a latitudinal increase in RS temperature sensitivity, with Q10 values ranging between 2.33 ±0.01 in tropical forests to 2.72 ±0.03 in tundra. This global trend has been widely observed, but has not previously been linked to soil communities

Sequential adjuvant chemotherapy and radiotherapy in endometrial cancer--results from two randomised studies.

INTRODUCTION: Endometrial cancer patients with high grade tumours, deep myometrial invasion, or advanced stage disease have a poor prognosis. Randomized studies have demonstrated prevention of loco-regional relapses with radiotherapy with no effect on overall survival. The possible additive effect of chemotherapy remains unclear. Two randomized clinical trials (NSGO-EC-9501/EORTC-55991 and MaNGO ILIADE-III) were undertaken to clarify if sequential combination of chemotherapy and radiotherapy improves progression-free survival in high-risk endometrial cancer. The two studies were pooled. METHODS: Patients (n=540; 534 evaluable) with operated endometrial cancer FIGO stage I-III with no residual tumour and prognostic factors implying high-risk were randomly allocated to adjuvant radiotherapy with or without sequential chemotherapy. RESULTS: In the NSGO/EORTC study, combined modality treatment was associated with a 36 % reduction in the risk for relapse or death (HR 0.64, 95 % CI 0.41-0.99; P=0.04); two-sided tests were used. The result from the MaNGO-study pointed in the same direction (HR 0.61), but was not significant. In combined analysis, the estimate of risk for relapse or death was similar but with narrower confidence limits (HR 0.63, CI 0.44-0.89; P=0.009). Neither study showed significant differences in overall survival. In combined analysis, overall survival approached statistical significance (HR 0.69, CI 0.46-1.03; P = 0.07) and cancer-specific survival was significant (HR 0.55, CI 0.35-0.88; p=0.01). CONCLUSION: Addition of adjuvant chemotherapy to radiation improves progression-free survival in operated endometrial cancer patients with no residual tumour and high risk profile. A remaining question for future studies is if addition of radiotherapy to chemotherapy improves the results

Strong correlation between the rates of intrinsically antibiotic-resistant species and the rates of acquired resistance in Gram-negative species causing bacteraemia, EU/EEA, 2016

BackgroundAntibiotic resistance, either intrinsic or acquired, is a major obstacle for treating bacterial infections.AimOur objective was to compare the country-specific species distribution of the four Gram-negative species Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter species and the proportions of selected acquired resistance traits within these species.MethodWe used data reported for 2016 to the European Antimicrobial Resistance Surveillance Network (EARS-Net) by 30 countries in the European Union and European Economic Area.ResultsThe country-specific species distribution varied considerably. While E. coli accounted for 31.9% to 81.0% (median: 69.0%) of all reported isolates, the two most common intrinsically resistant species P. aeruginosa and Acinetobacter spp. combined (PSEACI) accounted for 5.5% to 39.2% of isolates (median: 10.1%). Similarly, large national differences were noted for the percentages of acquired non-susceptibility to third-generation cephalosporins, carbapenems and fluoroquinolones. There was a strong positive rank correlation between the country-specific percentages of PSEACI and the percentages of non-susceptibility to the above antibiotics in all four species (rho > 0.75 for 10 of the 11 pairs of variables tested).ConclusionCountries with the highest proportion of P. aeruginosa and Acinetobacter spp. were also those where the rates of acquired non-susceptibility in all four studied species were highest. The differences are probably related to national differences in antibiotic consumption and infection prevention and control routines

State-of-the-art of 3D cultures (organs-on-a-chip) in safety testing and pathophysiology.

Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs--liver, lung, skin, brain--are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing

Crystal engineering of HIV-1 reverse transcriptase for structure-based drug design

HIV-1 reverse transcriptase (RT) is a primary target for anti-AIDS drugs. Structures of HIV-1 RT, usually determined at ∼2.5–3.0 Å resolution, are important for understanding enzyme function and mechanisms of drug resistance in addition to being helpful in the design of RT inhibitors. Despite hundreds of attempts, it was not possible to obtain the structure of a complex of HIV-1 RT with TMC278, a nonnucleoside RT inhibitor (NNRTI) in advanced clinical trials. A systematic and iterative protein crystal engineering approach was developed to optimize RT for obtaining crystals in complexes with TMC278 and other NNRTIs that diffract X-rays to 1.8 Å resolution. Another form of engineered RT was optimized to produce a high-resolution apo-RT crystal form, reported here at 1.85 Å resolution, with a distinct RT conformation. Engineered RTs were mutagenized using a new, flexible and cost effective method called methylated overlap-extension ligation independent cloning. Our analysis suggests that reducing the solvent content, increasing lattice contacts, and stabilizing the internal low-energy conformations of RT are critical for the growth of crystals that diffract to high resolution. The new RTs enable rapid crystallization and yield high-resolution structures that are useful in designing/developing new anti-AIDS drugs

Interventions to improve work outcomes in work-related PTSD: a systematic review

<p>Abstract</p> <p>Background</p> <p>Posttraumatic stress disorder acquired at work can be debilitating both for workers and their employers. The disorder can result in increased sick leave, reduced productivity, and even unemployment. Furthermore, workers are especially unlikely to return to their previous place of employment after a traumatic incident at work because of the traumatic memories and symptoms of avoidance that typically accompany the disorder. Therefore, intervening in work-related PTSD becomes especially important in order to get workers back to the workplace.</p> <p>Methods</p> <p>A systematic literature search was conducted using Medline, PsycINFO, Embase, and Web of Science. The articles were independently screened based on inclusion and exclusion criteria, followed by a quality assessment of all included articles.</p> <p>Results</p> <p>The systematic search identified seven articles for inclusion in the review. These consisted of six research articles and one systematic review. The review focused specifically on interventions using real exposure techniques for anxiety disorders in the workplace. In the research articles addressed in the current review, study populations included police officers, public transportation workers, and employees injured at work. The studies examined the effectiveness of EMDR, cognitive-behavioural techniques, and an integrative therapy approach called brief eclectic psychotherapy. Interestingly, 2 of the 6 research articles addressed add-on treatments for workplace PTSD, which were designed to treat workers with PTSD who failed to respond to traditional evidence-based psychotherapy.</p> <p>Conclusions</p> <p>Results of the current review suggest that work-related interventions show promise as effective strategies for promoting return to work in employees who acquired PTSD in the workplace. Further research is needed in this area to determine how different occupational groups with specific types of traumatic exposure might respond differently to work-tailored treatments.</p