Cannabis legalisation and testing for cannabis use in safety- and risk-sensitive environments

The legalisation of cannabis by the High Court of South Africa, which was confirmed by the Constitutional Court, imposes challenges to occupational medical practitioners acting as medical review officers in compliance testing and fit-for-service medical examinations. The lipophilic character of the psychoactive component of cannabis, delta-9-tetrahydrocannabinol (Δ9-THC), and its prolonged elimination half-life, create challenges for the ethically and scientifically correct management of the legal use of cannabis in risk-sensitive environments. Important issues to consider in testing for cannabis use are: the stance of ‘zero tolerance’; screening and confirmation cut-off concentrations; and the bio-matrices used for testing. Constitutional rights relate to privacy, freedom, autonomy, freedom of religion and the equal enjoyment of rights and privileges, which must be balanced against the health and safety of others

Unusual cause of mechanical ileus: abdominal cocoon syndrome

A 38-year-old black male patient was admitted with diarrhea and nausea over two days and aggravating pain in the meso- and epigastium that resolved after urination. He had no surgical history and only an episode of pulmonary tuberculosis five years earlier, for which he was properly treated. Physical examination revealed a tender and distended abdomen with clangorous sounds. His temperature was 36.1°C. Routine laboratory blood analyses were normal. An abdominal ultrasound revealed diffuse distention of the small intestine. A computed tomography (CT) scan showed a conglomerate of dilated small bowel loops in the meso- and hypogastrium, suggestive for a supravesical mechanical small bowel obstruction. Peritoneal thickening was seen in the right epigastrium (Figure A, white arrow). An explorative laparoscopy revealed a whitish, thickened membrane encapsulating the small bowels as a ‘cocoon’ (Figure B). Extensive adhesiolysis released an intestinal kinking in the lower abdomen, just above the bladder. No resection was needed. Histopathology of the membrane showed fibrocollagenous tissue with mixed inflammatory infiltrate

Spin injection across magnetic/non-magnetic interfaces with finite magnetic layers

We have reconsidered the problem of spin injection across ferromagnet/non-magnetic-semiconductor (FM/NMS) and dilute-magnetic-semiconductor/non-magnetic-semiconductor interfaces, for structures with \textit{finite} magnetic layers (FM or DMS). By using appropriate physical boundary conditions, we find expressions for the resistances of these structures which are in general different from previous results in the literature. When the magnetoresistance of the contacts is negligible, we find that the spin-accumulation effect alone cannot account for the $d$ dependence observed in recent magnetoresistance data. In a limited parameter range, our formulas predict a strong $d$ dependence arising from the magnetic contacts in systems where their magnetoresistances are sizable.Comment: 6 pages, 3 eps figs. (extended version- new title + two new figures added

Mineral resource management: Evaluating mineral resource throughput management

Mining operations are increasingly challenged to sustain and improve its profitability. Mineral Resource Throughput Management (MRTM) is showing immense promise to become a fit for use mining management and improvement methodology. Research indicated that the three dimensions of MRTM, namely physical and non-physical constraint management, product payability improvement and optimised decision-making are largely based on the theory of mechanistic and organic systems, the theory of constraints and chaos theory. It also enhances best practices in quality and mining operations management. Managing the impact of variable geology (variable ore and ore body morphology), mining (variable and changing process flow chains) and beneficiation (material compatibility) conditions as well as external variables on production within the MRTM context, mainly centres around understanding and predicting the correct flow behaviour of ore (physical and quality) in downstream processes and synchronisation of the total mining value chain

Feature-level domain adaptation

Domain adaptation is the supervised learning setting in which the training and test data are sampled from different distributions: training data is sampled from a source domain, whilst test data is sampled from a target domain. This paper proposes and studies an approach, called feature-level domain adaptation (FLDA), that models the dependence between the two domains by means of a feature-level transfer model that is trained to describe the transfer from source to target domain. Subsequently, we train a domain-adapted classifier by minimizing the expected loss under the resulting transfer model. For linear classifiers and a large family of loss functions and transfer models, this expected loss can be computed or approximated analytically, and minimized efficiently. Our empirical evaluation of FLDA focuses on problems comprising binary and count data in which the transfer can be naturally modeled via a dropout distribution, which allows the classifier to adapt to differences in the marginal probability of features in the source and the target domain. Our experiments on several real-world problems show that FLDA performs on par with state-of-the-art domain-adaptation techniques.Comment: 32 pages, 13 figures, 9 table

Drag of suction cup tags on swimming animals : modeling and measurement

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Mammal Science 30 (2014): 726–746, doi:10.1111/mms.12083.Bio-logging tags are widely used to study the behavior and movements of marine mammals with the tacit assumption of little impact to the animal. However, tags on fast-swimming animals generate substantial hydrodynamic forces potentially affecting behavior and energetics adversely, or promoting early removal of the tag. In this work, hydrodynamic loading of three novel tag housing designs are compared over a range of swimming speeds using computational fluid dynamics (CFD). Results from CFD simulation were verified using tag models in a water flume with close agreement. Drag forces were reduced by minimizing geometric disruptions to the flow around the housing, while lift forces were reduced by minimizing the frontal cross-sectional area of the housing and holding the tag close to the attachment surface. Hydrodynamic tag design resulted in an experimentally measured 60% drag force reduction in 5.6 m/s flow. For all housing designs, off-axis flow increased the magnitude of the force on the tag. Experimental work with a common dolphin (Delphinus delphis) cadaver indicates that the suction cups used to attach the types of tags described here provide sufficient attachment force to resist failure to predicted forces at swimming speeds of up to 10 m/s.This work was supported by NOPP with NSF funds through ONR Grant N00014-11-1- 0113. MJ was supported by NOPP and the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland)

Evaluation of concrete structures by combining non-destructive testing methods (SENSO project)

The management and maintenance of the built heritage is one of the main interests of the owners of concrete structures. The engineers wish to obtain quantitative information about concrete properties and their variability. Non-destructive testing (NDT) is very popular in this context as it quickly provides relevant information on the integrity and evolution of the material, but several kinds of indicators representative of the concrete condition need to be evaluated. A French Project, named SENSO, aims to develop methods for the non-destructive evaluation of concrete based on a multi-techniques approach. Several families of techniques are concerned (ultrasonic, electromagnetic, electrical, etc.). The main objective is to define the sensitivity of the techniques and the variability of the evaluation for each indicator concerned. To achieve this, a large experimental programme, involving a representative range of concretes and several indicators, has been carried out. A large database, linking the NDT observables and the indicators, allows the different observables to be distinguished in terms of quality (linked to the variability) and in terms of relevance for the characterisation of each indicator. The improvement of the indicator evaluation by means of technique combinatio

Amygdala Hypoactivity to Fearful Faces in Boys With Conduct Problems and Callous-Unemotional Traits

OBJECTIVE: Although early-onset conduct problems predict both psychiatric and health problems in adult life, little research has been done to index neural correlates of conduct problems. Emerging research suggests that a subgroup of children with conduct problems and elevated levels of callous-unemotional traits may be genetically vulnerable to manifesting disturbances in neural reactivity to emotional stimuli indexing distress. Using functional MRI, the authors evaluated differences in neural response to emotional stimuli between boys with conduct problems and elevated levels of callous-unemotional traits and comparison boys. METHOD: Seventeen boys with conduct problems and elevated levels of callous-unemotional traits and 13 comparison boys of equivalent age (mean=11 years) and IQ (mean=100) viewed blocked presentations of fearful and neutral faces. For each face, participants distinguished the sex of the face via manual response. RESULTS: Relative to the comparison group, boys with conduct problems and elevated levels of callous-unemotional traits manifested lesser right amygdala activity to fearful faces. CONCLUSIONS: This finding is in line with data from studies of adults with antisocial behavior and callous-unemotional traits (i.e., psychopaths), as well as from a recent study of adolescents with callous-unemotional traits, and suggests that the neural substrates of emotional impairment associated with callous-unemotional antisocial behavior are already present in childhood

The endocarditis team

Endocarditis is een ernstig ziektebeeld met een hoge mortaliteit en morbiditeit. In de klinische praktijk proberen we de behandeling van deze patiënten te verbeteren door goede en snelle diagnostiek en door tijdig adequate antibiotische en zo nodig chirurgische therapie te starten. In de nieuwste richtlijnen wordt het begrip ‘endocarditisteam’ geïntroduceerd als cruciaal onderdeel in de verbetering van de zorg voor patiënten met (een verdenking op) endocarditis. Er wordt gesteld dat endocarditis een multidisciplinaire aanpak vraagt omdat het een ziekte is met een grote variatie in presentatie, waarvoor expertise nodig is van verschillende specialisaties, en ook omdat patiënten in een vroege fase dienen te worden besproken in een chirurgisch team. Observationele studies tonen een belangrijke reductie in de mortaliteit van endocarditispatiënten die zijn besproken in een endocarditisteam.Dit artikel bespreekt de ervaringen met het opzetten van een endocarditisteam in twee verschillende regio’s in Nederland (Rotterdam-​Rijnmond en Groningen). Wat is belangrijk als het gaat om de structuur en functie van een endocarditisteam? Het opzetten van een endocarditisteam kan lastig zijn. Daarom geven we enkele praktische tips. Ten slotte wordt de toegevoegde waarde van een operationeel endocarditisteam geïllustreerd aan de hand van een casus.Endocarditis is a life-​threatening disease with high mortality and morbidity. In clinical practice, we try to improve the outcome of patients with endocarditis by implementing a better and faster diagnostic workup, a timely start of antimicrobial therapy and an early surgical intervention if required. In the most recent update of the guidelines for the management of patients with endocarditis, an Endocarditis team is put forward as crucial part in the improvement of care for patients with (suspected) endocarditis. They state that endocarditis requires a multidisciplinary approach since patients present with highly variable signs and symptoms, need a high-​standard of care from several medical specialists, and need to be discussed in a surgical team early in the course of the disease. Observational studies support this implementation by showing a marked decrease in mortality after dicussing endocarditis patients in an Endocarditis team. This article discusses the experience with the implementation of an Endocarditis team in two different regions of the Netherlands (Rotterdam-​Rijnmond and Groningen). Which aspects are important for the structure and function of an Endocarditis team? The setting up of an Endocarditis team can be difficult, therefore we provide some practical advice. Finally, an illustrative case is presented