An immersion freezing study of mineral dust and bacterial ice nucleating particles

Ice formation largely influences the properties of clouds and hence it has an important impact on weather and climate. Primary ice formation is a consequence of either homogeneous or heterogeneous ice nucleation. The latter process is catalyzed by a foreign substance called Ice Nucleating Particle (INP). Mineral dust particles were found to contribute to atmospheric INPs. Most types of mineral dust are ice active below -20 °C. In contrast, atmospheric observations indicate that immersion freezing as one of the most important heterogeneous ice nucleation processes can occur at temperatures higher than -15 °C. One possible explanation for cloud glaciation at high temperatures might be the presence of biological material (e.g. bacteria) inducing ice nucleation. Our fundamental process and even qualitative understanding concerning atmospheric heterogeneous ice nucleation is limited. In the framework of the present thesis, experimental and theoretical work was carried out to improve the basic understanding of the immersion freezing behavior of mineral dust and bacterial INPs. On the basis of model simulations immersion freezing experiments were designed at the Leipzig Aerosol Cloud Interaction Simulator (LACIS). The immersion freezing behavior of mineral dust and bacterial INPs was studied in dependence of temperature and particle surface area/number at LACIS. As a results of the present thesis, it was found that the immersion freezing behavior of kaolinite being a proxy of mineral dust INPs does not depend on the droplet volume, but on the particle surface area. The kaolinite particles investigated caused freezing below -30 °C. In contrast, Ice Nucleation Active (INA) protein complexes that are attributed to bacterial INPs were found to induce freezing at -7 °C. Furthermore, it was shown that the ice nucleation activity of protein complexes is very similar regardless of whether the INA protein complex is attached to the outer cell membrane of intact bacteria or to cell membrane fragments. The immersion freezing ability depends on the number and type of INA protein complexes present in the droplet ensemble. The immersion freezing ability of mineral dust and bacterial INPs was parameterized accounting for the time effect. With this, results from literature could be reproduced for both INP types. These parameterizations can be used in e.g. cloud resolving atmospheric models

TRADE POLICY AND ENVIRONMENTAL QUALITY: THE CASE OF EXPORT SUBSIDIES

The United States and the European Union both employ export subsidies to stimulate wheat trade and to increase their competitiveness in world markets. The environmental consequences of these policies are being questioned. We simulate reducing or removing export subsidies for wheat from the United States and the EU using a multicountry partial equilibrium model, and we analyze the impact of export subsidy policy reform on nitrogen fertilizer and other chemical use. Our findings indicate that the U.S. EEP program cannot be blamed for environmental degradation in terms of nitrate leaching, while EU wheat subsides make only a small contribution to nitrate pollution.Environmental Economics and Policy, International Relations/Trade,

Observational evidence of strengthening of the Brewer-Dobson circulation since 1980

The change of the Brewer-Dobson circulation (BDC) over the period of 1980–2009 is examined through a combined analysis of satellite Microwave Sounding Unit (MSU/AMSU) lower stratospheric temperatures (TLS), ERA-Interim reanalysis data, and observed estimates of changes in ozone, water vapor, well-mixed greenhouse gases, and stratospheric aerosols. The MSU/AMSU-observed tropical TLS trend is first empirically separated into a dynamic component associated with the BDC changes and a radiative component due to the atmospheric composition changes. The derived change in the dynamic component suggests that the annual mean BDC has accelerated in the last 30 years (at the 90% confidence interval), with most of the change coming from the Southern Hemisphere. The annual mean Northern Hemisphere contribution to the acceleration is not statistically significant. The radiative component of tropical TLS trends is independently checked using observed changes in stratospheric composition. It is shown that the changes in ozone, stratospheric aerosols, well-mixed greenhouse gases, and water vapor make important contributions to the radiative component of tropical TLS trends. Despite large uncertainties in lower stratospheric cooling associated with uncertainties in observed ozone and water vapor changes, this derived radiative component agrees with the empirically inferred radiative component, both in terms of its average value and small seasonal dependence. By establishing a relationship between tropical residual vertical velocity at 70 hPa and TLS, we show that the relative strengthening of the annual mean BDC is about 2.1% per decade for 1980–2009, supporting the results from state-of-the-art chemistry-climate model simulations.United States. National Aeronautics and Space Administration (grant NNX13AN49G)United States. National Aeronautics and Space Administration (NNX14AB28G)United States. Department of Energy. Office of Science (grant DE-SC0010557)National Science Foundation (U.S.) (grant 1342810)National Science Foundation (U.S.) (grant 1461517

Playing 'Tetris' reduces the strength, frequency and vividness of naturally occurring cravings.

Elaborated Intrusion Theory (EI) postulates that imagery is central to craving, therefore a visually based task should decrease craving and craving imagery. This study provides the first laboratory test of this hypothesis in naturally occurring, rather than artificially induced, cravings. Participants reported if they were experiencing a craving and rated the strength, vividness and intrusiveness of their craving. They then either played 'Tetris' or they waited for a computer program to load (they were told it would load, but it was designed not to). Before task completion, craving scores between conditions did not differ; after, however, participants who had played 'Tetris' had significantly lower craving and less vivid craving imagery. The findings support EI theory, showing that a visuospatial working memory load reduces naturally occurring cravings, and that Tetris might be a useful task for tackling cravings outside the laboratory. Methodologically, the findings show that craving can be studied in the laboratory without using craving induction procedures

Care management for persistent pain: An introduction

Persistent pain is a frequently occurring condition with significant economic, clinical, and humanistic implications, for both individuals and society. Current literature, however, points to unresolved issues with regard to its identification, assessment, diagnosis, and treatment, and a number of suggestions have been made for improving the quality of care for pain sufferers. Because persistent pain shares many of the salient features of other chronic conditions such as diabetes and congestive heart failure, it is reasonable to believe that the adoption of a coordinated approach to care management could substantially improve the quality of care. Several strategiesincluding identification, appropriate referral, education, and planning can and should be implemented to offer comprehensive, individualized treatment alternatives that are not currently available and that improve patient outcomes, including quality of life

Cognitive and behavioural strategies for self-directed weight loss:systematic review of qualitative studies

Aim We conducted a systematic review of qualitative studies to examine the strategies people employ as part of self-directed weight loss attempts, map these to an existing behaviour change taxonomy, and explore attitudes and beliefs surrounding these strategies. Methods Seven electronic databases were searched in December 2015 for qualitative studies in overweight and obese adults attempting to lose weight through behaviour change. We were interested in strategies used by participants in self-directed efforts to lose weight. Two reviewers extracted data from included studies. Thematic and narrative synthesis techniques were used. Results 31 studies, representing over 1,000 participants, were included. Quality of the included studies was mixed. The most commonly covered types of strategies were restrictions, self-monitoring, scheduling, professional support and weight management aids. With the exception of scheduling, for which participant experiences were predominantly positive, participants’ attitudes and beliefs surrounding implementation of these groups of strategies were mixed. Two new groups of strategies were added to the existing taxonomy: reframing and self-experimentation. Conclusions This review demonstrates that at present, interventions targeting individuals engaged in self-management of weight do not necessarily reflect lived experiences of self-directed weight loss.</p

Use of cognitive and behavioral strategies during a weight loss program: a secondary analysis of the Doctor Referral of Overweight People to Low-Energy Total Diet Replacement Treatment (DROPLET) trial

Background: Achieving a sustained energy deficit is essential for weight loss, but the cognitive and behavioral strategies that support this goal are unclear. Objective: The goal of this study was to investigate the number and type of cognitive and behavioral strategies used by participants who were enrolled in a 1-year weight loss trial and to explore associations between strategies and magnitude of weight loss at 3 months and 1 year. Design: The study is a secondary post-hoc exploratory analysis of data collected as part of the Doctor Referral of Overweight People to Low-Energy total diet replacement Treatment (DROPLET), a randomized controlled trial conducted in general practices in England, United Kingdom, between January 2016 and August 2017. Participants/setting: This study involved 164 participants from both intervention and control groups of the DROPLET trial who completed the Oxford Food and Behaviours (OxFAB) questionnaire to assess the use of 115 strategies grouped into 21 domains used to manage their weight. Interventions: Participants were randomized to either a behavioral weight loss program involving 8 weeks total diet replacement (TDR) and 4 weeks of food reintroduction or a program delivered by a medical practice nurse over a 3-month period (usual care [UC]). Main outcome measures: Weight was objectively measured at baseline, 3 months, and 1 year. Cognitive and behavioral strategies used to support weight loss were assessed using the OxFAB questionnaire at 3 months. Statistical analysis performed: Exploratory factor analysis was used to generate data-driven patterns of strategy use, and a linear mixed-effects model was used to examine associations between use of these patterns and weight change. Results: No evidence was found of a difference in the number of strategies (mean difference, 2.41; 95% confidence interval [CI], −0.83, 5.65) or the number of domains used (mean difference, −0.23; 95% CI, −0.69, 0.23) between the TDR group and the UC group. The number of strategies was not associated with weight loss at either 3 months (−0.02 kg; 95% CI, −0.11, 0.06) or 1 year (−0.05 kg; 95% CI, −0.14, 0.02). Similarly, the number of domains used was not associated with weight loss at 3 months (−0.02 kg; 95% CI, −0.53, 0.49) or 1 year (−0.07 kg; 95% CI, −0.60, 0.46). Factor analysis identified four coherent patterns of strategy use, identified as Physical Activity, Motivation, Planned Eating, and Food Purchasing patterns. Greater use of strategies in the Food Purchasing (−2.6 kg; 95% CI, −4.42, −0.71) and Planned Eating patterns (−3.20 kg; 95% CI, −4.94, −1.46) was associated with greater weight loss at 1 year. Conclusions:The number of cognitive and behavioral strategies or domains used does not appear to influence weight loss, but the types of strategy appear of greater importance. Supporting people to adopt strategies linked to planned eating and food purchasing may aid long-term weight loss

Bloom Syndrome Helicase Promotes Meiotic Crossover Patterning and Homolog Disjunction

In most sexually reproducing organisms, crossover formation between homologous chromosomes is necessary for proper chromosome disjunction during meiosis I. During meiotic recombination, a subset of programmed DNA double-strand breaks (DSBs) are repaired as crossovers, with the remainder becoming noncrossovers [1]. Whether a repair intermediate is designated to become a crossover is a highly regulated decision that integrates several crossover patterning processes, both along chromosome arms (interference and the centromere effect) and between chromosomes (crossover assurance) [2]. Because the mechanisms that generate crossover patterning have remained elusive for over a century, it has been difficult to assess the relationship between crossover patterning and meiotic chromosome behavior. We show here that meiotic crossover patterning is lost in Drosophila melanogaster mutants that lack the Bloom syndrome helicase. In the absence of interference and the centromere effect, crossovers are distributed more uniformly along chromosomes. Crossovers even occur on the small chromosome 4, which normally never has meiotic crossovers [3]. Regulated distribution of crossovers between chromosome pairs is also lost, resulting in an elevated frequency of homologs that do not receive a crossover, which in turn leads to elevated nondisjunction

Supplementary data for article: Molloy, S.; Nikodinović-Runić, J.; Martin, L. B.; Hartmann, H.; Solano, F.; Decker, H.; O’Connor, K. E. Engineering of a Bacterial Tyrosinase for Improved Catalytic Efficiency towards D-Tyrosine Using Random and Site Directed Mutagenesis Approaches. Biotechnology and Bioengineering 2013, 110 (7), 1849–1857. https://doi.org/10.1002/bit.24859

Supporting information for: [https://doi.org/10.1002/bit.24859]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1359]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3491