Controls on gut phosphatisation : the trilobites from the Weeks Formation Lagerstätte (Cambrian; Utah)

Despite being internal organs, digestive structures are frequently preserved in Cambrian Lagerstätten. However, the reasons for their fossilisation and their biological implications remain to be thoroughly explored. This is particularly true with arthropods--typically the most diverse fossilised organisms in Cambrian ecosystems--where digestive structures represent an as-yet underexploited alternative to appendage morphology for inferences on their biology. Here we describe the phosphatised digestive structures of three trilobite species from the Cambrian Weeks Formation Lagerstätte (Utah). Their exquisite, three-dimensional preservation reveals unique details on trilobite internal anatomy, such as the position of the mouth and the absence of a differentiated crop. In addition, the presence of paired pygidial organs of an unknown function is reported for the first time. This exceptional material enables exploration of the relationships between gut phosphatisation and the biology of organisms. Indeed, soft-tissue preservation is unusual in these fossils as it is restricted to the digestive structures, which indicates that the gut played a central role in its own phosphatisation. We hypothesize that the gut provided a microenvironment where special conditions could develop and harboured a source of phosphorus. The fact that gut phosphatization has almost exclusively been observed in arthropods could be explained by their uncommon ability to store ions (including phosphorous) in their digestive tissues. However, in some specimens from the Weeks Formation, the phosphatisation extends to the entire digestive system, suggesting that trilobites might have had some biological particularities not observed in modern arthropods. We speculate that one of them might have been an increased capacity for ion storage in the gut tissues, related to the moulting of their heavily-mineralised carapace

Genetic diversity of the dengue vector Aedes aegypti in Australia and implications for future surveillance and mainland incursion monitoring

In February 2004, the dicovery of an incursion of the dengue vector Aedes aegypti into the town of Tennant Creek in the Northern Territory caused concern for the Northern Territory health authorities who proceeded to implement a Commonwealth-funded eradication program. To determine the prigin of the incursion, we performed a genetic analysis on Ae. aegypti from several Queensland and overseas localities. A comparison of DNA sequences from the mitochondrial cytochrome oxidase 1 gene indicated that the incursion was probably from Cairns or Camooweal. This genetic marker was also useful in identifying a separate Townsville haplotype population and another population on Thursday Island in the Torres Strait that was genetically divergent to the mainland populations. The possible use of this marker as a surveillance tool for identifying the origins of local and overseas incursions is discussed

An Empirical Study on Collaborative Architecture Decision Making in Software Teams

Architecture decision making is considered one of the most challenging cognitive tasks in software development. The objective of this study is to explore the state of the practice of architecture decision making in software teams, including the role of the architect and the associated challenges. An exploratory case study was conducted in a large software company in Europe and fifteen software architects were interviewed as the primary method of data collection. The results reveal that the majority of software teams make architecture decisions collaboratively. Especially, the consultative decision- making style is preferred as it helps to make decisions efficiently while taking the opinions of the team members into consideration. It is observed that most of the software architects maintain a close relationship with the software teams. Several organisational, process and human related challenges and their impact on architecture decision-making are also identified

False positive circumsporozoite protein ELISA: a challenge for the estimation of the entomological inoculation rate of malaria and for vector incrimination

<p>Abstract</p> <p>Background</p> <p>The entomological inoculation rate (EIR) is an important indicator in estimating malaria transmission and the impact of vector control. To assess the EIR, the enzyme-linked immunosorbent assay (ELISA) to detect the circumsporozoite protein (CSP) is increasingly used. However, several studies have reported false positive results in this ELISA. The false positive results could lead to an overestimation of the EIR. The aim of present study was to estimate the level of false positivity among different anopheline species in Cambodia and Vietnam and to check for the presence of other parasites that might interact with the anti-CSP monoclonal antibodies.</p> <p>Methods</p> <p>Mosquitoes collected in Cambodia and Vietnam were identified and tested for the presence of sporozoites in head and thorax by using CSP-ELISA. ELISA positive samples were confirmed by a <it>Plasmodium </it>specific PCR. False positive mosquitoes were checked by PCR for the presence of parasites belonging to the Haemosporidia, Trypanosomatidae, Piroplasmida, and Haemogregarines. The heat-stability and the presence of the cross-reacting antigen in the abdomen of the mosquitoes were also checked.</p> <p>Results</p> <p>Specimens (N = 16,160) of seven anopheline species were tested by CSP-ELISA for <it>Plasmodium falciparum </it>and <it>Plasmodium vivax </it>(Pv210 and Pv247). Two new vector species were identified for the region: <it>Anopheles pampanai </it>(<it>P. vivax</it>) and <it>Anopheles barbirostris </it>(<it>Plasmodium malariae</it>). In 88% (155/176) of the mosquitoes found positive with the <it>P. falciparum </it>CSP-ELISA, the presence of <it>Plasmodium </it>sporozoites could not be confirmed by PCR. This percentage was much lower (28% or 5/18) for <it>P. vivax </it>CSP-ELISAs. False positive CSP-ELISA results were associated with zoophilic mosquito species. None of the targeted parasites could be detected in these CSP-ELISA false positive mosquitoes. The ELISA reacting antigen of <it>P. falciparum </it>was heat-stable in CSP-ELISA true positive specimens, but not in the false positives. The heat-unstable cross-reacting antigen is mainly present in head and thorax and almost absent in the abdomens (4 out of 147) of the false positive specimens.</p> <p>Conclusion</p> <p>The CSP-ELISA can considerably overestimate the EIR, particularly for <it>P. falciparum </it>and for zoophilic species. The heat-unstable cross-reacting antigen in false positives remains unknown. Therefore it is highly recommended to confirm all positive CSP-ELISA results, either by re-analysing the heated ELISA lysate (100°C, 10 min), or by performing <it>Plasmodium </it>specific PCR followed if possible by sequencing of the amplicons for <it>Plasmodium </it>species determination.</p

Using motivational techniques to reduce cardiometabolic risk factors in long term psychiatric inpatients: A naturalistic interventional study

Background People with severe mental illness have markedly reduced life expectancy; cardiometabolic disease is a major cause. Psychiatric hospital inpatients have elevated levels of cardiometabolic risk factors and are to a high degree dependent of the routines and facilities of the institutions. Studies of lifestyle interventions to reduce cardiometabolic risk in psychiatric inpatients are few. The current study aimed at assessing the feasibility and effects of a lifestyle intervention including Motivational Interviewing (MI) on physical activity levels, cardiometabolic risk status and mental health status in psychotic disorder inpatients. Methods Prospective naturalistic intervention study of 83 patients at long term inpatient psychosis treatment wards in South-Eastern Norway. Patients were assessed 3–6 months prior to, at start and 6 months after a life-style intervention program including training of staff in MI, simple changes in routines and improvements of facilities for physical exercise. Assessments were done by clinical staff and included level of physical activity, motivation, life satisfaction, symptom levels (MADRS, AES-C, PANSS, and GAF) as well as anthropometric and biochemical markers of cardiometabolic risk. A mixed model was applied to analyze change over time. Results A total of 88% of patients received MI interventions, with a mean of 2.5 MI interventions per week per patient. The physical activity level was not increased, but activity level was positively associated with motivation and negatively associated with positive symptoms. Triglyceride levels and number of smokers were significantly reduced and a significant decrease in symptom levels was observed. Conclusions The current results suggest that a simple, low cost life-style intervention program focusing on motivational change is feasible and may reduce symptoms and improve lifestyle habits in psychosis patients in long term treatment facilities. Similar programs may easily be implemented in other psychiatric hospitals.submittedVersio

Synergism between particle-based multiplexing and microfluidics technologies may bring diagnostics closer to the patient

In the field of medical diagnostics there is a growing need for inexpensive, accurate, and quick high-throughput assays. On the one hand, recent progress in microfluidics technologies is expected to strongly support the development of miniaturized analytical devices, which will speed up (bio)analytical assays. On the other hand, a higher throughput can be obtained by the simultaneous screening of one sample for multiple targets (multiplexing) by means of encoded particle-based assays. Multiplexing at the macro level is now common in research labs and is expected to become part of clinical diagnostics. This review aims to debate on the “added value” we can expect from (bio)analysis with particles in microfluidic devices. Technologies to (a) decode, (b) analyze, and (c) manipulate the particles are described. Special emphasis is placed on the challenges of integrating currently existing detection platforms for encoded microparticles into microdevices and on promising microtechnologies that could be used to down-scale the detection units in order to obtain compact miniaturized particle-based multiplexing platforms

Identification and Characterization of Novel Mutations in the Human Gene Encoding the Catalytic Subunit Calpha of Protein Kinase A (PKA)

The genes PRKACA and PRKACB encode the principal catalytic (C) subunits of protein kinase A (PKA) Cα and Cβ, respectively. Cα is expressed in all eukaryotic tissues examined and studies of Cα knockout mice demonstrate a crucial role for Cα in normal physiology. We have sequenced exon 2 through 10 of PRKACA from the genome of 498 Norwegian donors and extracted information about PRKACA mutations from public databases. We identified four interesting nonsynonymous point mutations, Arg45Gln, Ser109Pro, Gly186Val, and Ser263Cys, in the Cα1 splice variant of the kinase. Cα variants harboring the different amino acid mutations were analyzed for kinase activity and regulatory (R) subunit binding. Whereas mutation of residues 45 and 263 did not alter catalytic activity or R subunit binding, mutation of Ser109 significantly reduced kinase activity while R subunit binding was unaltered. Mutation of Cα Gly186 completely abrogated kinase activity and PKA type I but not type II holoenzyme formation. Gly186 is located in the highly conserved DFG motif of Cα and mutation of this residue to Val was predicted to result in loss of binding of ATP and Mg2+, which may explain the kinetic inactivity. We hypothesize that individuals born with mutations of Ser109 or Gly186 may be faced with abnormal development and possibly severe disease

Competitive Tendering In The Netherlands: Central Planning Or Functional Specifications?

Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne