Thermally safe operation of a cooled semi-batch reactor: slow liquid-liquid reactions

Thermally safe operation of a semi-batch reactor (SBR) implies that conditions leading to strong accumulation of unreacted reactants must be avoided. All thermal responses of a SBR, in which a slow liquid-liquid reaction takes place, can be represented in a diagram with the kinetics, cooling capacity and potential temperature rise as the keyfactors. Slow reactions taking place in the dispersed phase were found to be more prone to accumulation than reactions in the continuous phase. An overheat situation can develop after the reactants have accumulated in their ”own“ phase due to a slight overcooling

Necrotizing Pancreatitis: New Definitions and a New Era in Surgical Management

Background: Necrotizing pancreatitis is a challenging condition that requires surgical treatment commonly and is associated with substantial morbidity and mortality. Over the past decade, new definitions have been developed for standardization of severity of acute and necrotizing pancreatitis, and new management techniques have emerged based on prospective, randomized clinical trials. Methods: Review of English-language literature. Results: A new international classification of acute pancreatitis has been developed by PANCREA (Pancreatitis Across Nations Clinical Research and Education Alliance) to replace the Atlanta Classification. It is based on the actual local (whether pancreatic necrosis is present or not, whether it is sterile or infected) and systemic determinants (whether organ failure is present or not, whether it is transient or persistent) of severity. Early management requires goal-directed fluid resuscitation (with avoidance of over-resuscitation and abdominal compartment syndrome), assessment of severity of pancreatitis, diagnostic computed tomography (CT) imaging to assess for necrotizing pancreatitis, consideration of endoscopic retrograde cholangiopancreatography (ERCP) for biliary pancreatitis and early enteral nutrition support. Antibiotic prophylaxis is not recommended. Therapeutic antibiotics are required for treatment of documented infected pancreatic necrosis. The initial treatment of infected pancreatic necrosis is percutaneous catheter or endoscopic (transgastric/transduodenal) drainage with a second drain placement as required. Lack of clinical improvement after these initial procedures warrants consideration of minimally invasive techniques for pancreatic necrosectomy including video-assisted retroperitoneal debridement (VARD), minimally invasive retroperitoneal pancreatectomy (MIRP), or transluminal direct endoscopic necrosectomy (DEN). Open necrosectomy is associated with substantial morbidity, but to date no randomized trial has documented superiority of either minimally invasive or open surgical technique. Additional trials are underway to address this. Conclusions: Severe acute and necrotizing pancreatitis requires a multi-disciplinary treatment strategy that must be individualized for each patient. Optimal treatment of necrotizing pancreatitis now requires a staged, multi-disciplinary, minimally invasive ?step-up? approach that includes a team of interventional radiologists, therapeutic endoscopists, and surgeons.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140218/1/sur.2014.123.pd

The Feeding Ecology of the Gastropod Batillaria attramentaria, Chuckanut Mudflat, Washington

The deposit-feeding gastropod Batillaria attramentaria lives upon algal mat, mud, gravelly mud and gravelly sand substrates at Chuckanut Mudflat, Washington and upon homogeneous sand at Semiahmoo Spit, Washington. The efficiencies and rates·of feeding by B. attramentaria on these substrates were studied in order to determine whether an optimal foraging strategy exists in this species. Gut content analysis of snails taken from the various substrates revealed a fairly constant diet of sediment particles and diatoms, along with occasional animal fragments. Diatoms were ingested with efficiencies ranging from 38 to 51 percent; digestive efficiency increased with increasing availability of diatoms in sediments. Snail fecal pellets contained two to seven times more organic carbon than was contained in sediments. Carbon enrichment of pellets decreased with increasing availability of carbon in the sediments. Gut residence times for materials ingested ranged from 260 to 400 minutes and varied inversely with the percentage of mud in the sediments. Pellet egestion rates increased with increasing percentage of mud in sediments, and ranged from 0.1 to 7.0 mg snail-1 hr-1. Results for gut content analysis, gut residence and egestion rate experiments supported the hypothesis that Batillaria attramentaria feeds selectively on mud and diatoms regardless of sediment type. Egestion rate, diatom digestion and carbon enrichment results pointed to an energy optimization strategy in this species

Psychological functioning in adolescents referred to specialist gender identity clinics across Europe : a clinical comparison study between four clinics

Adolescents seeking professional help with their gender identity development often present with psychological difficulties. Existing literature on psychological functioning of gender diverse young people is limited and mostly bound to national chart reviews. This study examined the prevalence of psychological functioning and peer relationship problems in adolescents across four European specialist gender services (The Netherlands, Belgium, the UK, and Switzerland), using the Child Behavioural Checklist (CBCL) and the Youth Self-Report (YSR). Differences in psychological functioning and peer relationships were found in gender diverse adolescents across Europe. Overall, emotional and behavioural problems and peer relationship problems were most prevalent in adolescents from the UK, followed by Switzerland and Belgium. The least behavioural and emotional problems and peer relationship problems were reported by adolescents from The Netherlands. Across the four clinics, a similar pattern of gender differences was found. Birth-assigned girls showed more behavioural problems and externalising problems in the clinical range, as reported by their parents. According to self-report, internalising problems in the clinical range were more prevalent in adolescent birth-assigned boys. More research is needed to gain a better understanding of the difference in clinical presentations in gender diverse adolescents and to investigate what contextual factors that may contribute to this

Klimaatdijk een verkenning

IntroductionClimate change, land subsidence and the increasing economic value of property and activities in flood-prone areas justify the question of how we can maintain flood protection in the Netherlands at its current level, or even improve it. The changing social, scientific and technical developments and insights of our day mean that the time is ripe to consider alternatives for flood protection, other than the customary call to raise the dikes yet higher, time and again.The Climate DikeThe Climate Dike is a logical addition to the current practice of raising and reinforcing dikes. A Climate Dike is defined here as ¿a collective term for design components that result in flood defences so robust that they are virtually impossible to breach, and thus offer lasting protection, even in the face of ongoing climate change The Climate Dike concerns a type of dike that allows some wave overflow and even a limited amount of flooding, but which prevents the uncontrolled catastrophic dike breaks associated with devastating flooding of the hinterland. The number of potential victims and the resulting damage are therefore in no way comparable to those incurred when a traditional dike breaks. The risk, calculated as a product of the probability of occurrence and the resulting damage, is therefore drastically reduced.Another feature of the Climate Dike is its integrated multi-functional character. On it, a wider range of socio-economic interests can be built than on traditional dikes. This means that greater opportunities for financing also become available.Before the Climate Dike can be approached as a serious alternative, clarity is needed on the relevant information, experience, policy and knowledge that exists (and does not yet exist). The current inventory was conducted with that requirement in mind.The authors looked at, among others, projects that presented problems and challenges similar to those expected in development of a Climate Dike. These relate, among others, to technical,economic, social and spatial issues.A long time horizonBecause of its more multidisciplinary character, development of a Climate Dike requires a longer time horizon than a traditional dike. The current system of 5-yearly testing, in which dikes that fail to meet current safety standards are immediately subjected to an urgent upgrade trajectory, provides an inadequate framework for developing the Climate Dike.In the current system, evolving scientific insights, environmental conditions and safety requirements could mean that even immediately after a dike has been strengthened, the next reinforcement is just around the corner. Such a situation is clearly undesired for a multifunctional Climate Dike with, for example, buildings on it. Also, after its construction, a Climate Dike has to be able to guarantee safety for many more decades than a traditional dike, and to do so in a way that other interests can build on, literally and figuratively. A longer planning horizon and new means of anticipating on future developments are therefore essential.ChallengingThe Climate Dike has no set dimensions or form, though it does tend to be wider and less steep than traditional dikes and include a protection zone parallel to existing flood defences. It goes without saying that not every aspect of the Climate Dike concept, which is often broad in both functional and physical terms, will be applicable at every location.One of the many challenges arising in applying the Climate Dike concept is the question of how to effectively look ahead over an extremely long stretch of time (for example, a century), since we cannot predict with any certainty how society will look after such a long period. How can ideas and procedures be tailored to as yet unknown future developments? How can we best ensure the ability to adapt to new situations and insights?One of the complexities involved in developing a Climate Dike is the use of space. How can the required space be secured without having to demolish large numbers of buildings and infrastructure and without excluding large zones of land from any possible socio-economic activity, perhaps for many decades?Costs and benefitsA Climate Dike is costly, if one limits the field of vision to the safety aspect and the traditional time horizon of 50 years. Broaden the view to bring in multiple interests that over a longer time period can, literally and figuratively, build on the presence of the Climate Dike, then this form of flood protection becomes much more financially attractive. Certainly when considering other options for flood protection, such as compartmentalisation dikes or the raising of immense tracts of land.Law and legislationTo give designers and managers of flood defences more opportunity to develop the Climate Dike, modifications are required in current design guidelines and technical prerequisites. Also, it must be made clear whether and how a Climate Dike is to be subjected to the 5-yearly testing cycle. Is such testing needed if the dike is considered to be virtually impossible to breach? How do we deal with the probability of flooding versus the risk of a dike break? Current law and legislation are geared fairly specifically to the traditional dike. Alternative concepts such as the Climate Dike call for modified policies, laws and legislation, as well as newly formulated design requirements and prerequisites. Or it will have to be made clearer how these should be interpreted for such innovative concepts

Re-evaluating safety risks of multifunctional dikes with a probabilistic risk framework

It is not uncommon for a flood defence to be combined with other societal uses as a multifunctional flood defence, from housing in urban areas to nature conservation in rural areas. The assessment of the safety of multifunctional flood defences is often done using conservative estimates. This study synthesizes new probabilistic approaches to evaluate the safety of multifunctional flood defences employed in the Netherlands and explores the results of these approaches. In this paper a case representing a typical Dutch river dike combining a flood safety function with a nature and housing function is assessed by its probability of failure for multiple reinforcement strategies considering multiple relevant failure mechanisms. Results show how the conservative estimates of multifunctional flood defences lead to a systematic underestimation of the reliability of these dikes. Furthermore, in a probabilistic assessment uncertainties introduced by multifunctional elements affect the level of safety of the dike proportional to the reliability of the dike itself. Hence, dikes with higher protection levels are more suitable to be combined with potentially harmful uses for safety, whereas dikes with low protection levels can benefit most from uses that contribute to safety.</p

Isolation of an acetyl-CoA synthetase gene (ZbACS2) from Zygosaccharomyces bailii

A gene homologous to Saccharomyces cerevisiae ACS genes, coding for acetyl-CoA synthetase, has been cloned from the yeast Zygosaccharomyces bailii ISA 1307, by using reverse genetic approaches. A probe obtained by PCR amplification from Z. bailii DNA, using primers derived from two conserved regions of yeast ACS proteins, RIGAIHSVVF (ScAcs1p; 210–219) and RVDDVVNVSG (ScAcs1p; 574–583), was used for screening a Z. bailii genomic library. Nine clones with partially overlapping inserts were isolated. The sequenced DNA fragment contains a complete ORF of 2027 bp (ZbACS2) and the deduced polypeptide shares significant homologies with the products of ACS2 genes from S. cerevisiae and Kluyveromyces lactis (81% and 82% identity and 84% and 89% similarity, respectively). Phylogenetic analysis shows that the sequence of Zbacs2 is more closely related to the sequences from Acs2 than to those from Acs1 proteins. Moreover, this analysis revealed that the gene duplication producing Acs1 and Acs2 proteins has occurred in the common ancestor of S. cerevisiae, K. lactis, Candida albicans, C. glabrata and Debaryomyces hansenii lineages. Additionally, the cloned gene allowed growth of S. cerevisiae Scacs2 null mutant, in medium containing glucose as the only carbon and energy source, indicating that it encodes a functional acetyl-CoA synthetase. Also, S. cerevisiae cells expressing ZbACS2 have a shorter lag time, in medium containing glucose (2%, w/v) plus acetic acid (0.1–0.35%, v/v). No differences in cell response to acetic acid stress were detected both by specific growth and death rates. The mode of regulation of ZbACS2 appears to be different from ScACS2 and KlACS2, being subject to repression by a glucose pulse in acetic acid-grown cells. The nucleotide sequence of a common 5269 bp fragment has been deposited in the EMBL Data Library under Accession No. AJ314837.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI P/AGR/11135/9

Measuring Bird Damage to Three Fruit Crops: A Comparison of Grower and Field Estimates

Birds are common pests in fruit orchards. They frequently consume and damage fruit resulting in decreased yields for growers. The true extent of damage is difficult to measure. Producer surveys are often implemented to estimate damage, but the accuracy of these estimates is uncertain. We compared damage estimates obtained through field studies with estimates from a producer survey for three fruit crops: wine grapes, sweet cherries, and ‘Honeycrisp’ apples. We also analyzed relationships between use of various damage management methods and levels of bird damage. We found wine grape and sweet cherry growers accurately assessed bird damage, while ‘Honeycrisp’ apple growers may overestimate damage. Growing region appears to be an important damage predictor for wine grape and sweet cherry crops. Significant relationships between management methods and damage were positive, suggesting growers only use these methods when bird damage is substantial

Deltadijken dragen bij aan ‘robuust’ systeem

Verhoging en versterking van dijken is niet het enige mogelijke antwoord op extreem hoge afvoeren van rivieren. Men kan ook kijken naar de 'robuustheid' van het systeem: is een gebied als geheel - en dus niet alleen de dijk - voorbereid op het vele water? En welke rol kunnen deltadijken daarbij spelen