Anatomical landmarks for transnasal endoscopic skull base surgery.

Resection of midline skull base lesions involve approaches needing extensive neurovascular manipulation. Transnasal endoscopic approach (TEA) is minimally invasive and ideal for certain selected lesions of the anterior skull base. A thorough knowledge of endonasal endoscopic anatomy is essential to be well versed with its surgical applications and this is possible only by dedicated cadaveric dissections. The goal in this study was to understand endoscopic anatomy of the orbital apex, petrous apex and the pterygopalatine fossa. Six cadaveric heads (3 injected and 3 non injected) and 12 sides, were dissected using a TEA outlining systematically, the steps of surgical dissection and the landmarks encountered. Dissection done by the "2 nostril, 4 hands" technique, allows better transnasal instrumentation with two surgeons working in unison with each other. The main surgical landmarks for the orbital apex are the carotid artery protuberance in the lateral sphenoid wall, optic nerve canal, lateral optico-carotid recess, optic strut and the V2 nerve. Orbital apex includes structures passing through the superior and inferior orbital fissure and the optic nerve canal. Vidian nerve canal and the V2 are important landmarks for the petrous apex. Identification of the sphenopalatine artery, V2 and foramen rotundum are important during dissection of the pterygopalatine fossa. In conclusion, the major potential advantage of TEA to the skull base is that it provides a direct anatomical route to the lesion without traversing any major neurovascular structures, as against the open transcranial approaches which involve more neurovascular manipulation and brain retraction. Obviously, these approaches require close cooperation and collaboration between otorhinolaryngologists and neurosurgeons.

Applying RADIC in Open MPI: the methodology used to implement RADIC over a Message Passing Library

Fault tolerance has become a major issue for computer and software engineers because the occurrence of faults increases the cost of using a parallel computer. RADIC is the fault tolerance architecture for message passing systems which is transparent, decentralized, flexible and scalable. This master thesis presents the methodology used to implement the RADIC architecture over Open MPI, a well-know large-used message passing library. This implementation kept the RADIC architecture characteristics. In order to validate the implementation we have executed a synthetic ping program, besides, to evaluate the implementation performance we have used the NAS Parallel Benchmarks. The results prove that the RADIC architecture performance depends on the communication pattern of the parallel application which is running. Furthermore, our implementation proves that the RADIC architecture could be implemented over an existent message passing library.

Congenital heart disease in pregnancies complicated by maternal diabetes mellitus. An international clinical collaboration, literature review, and meta-analysis.

PURPOSE: Investigation of the incidence and distribution of congenital structural cardiac malformations among the offspring of mothers with diabetes type 1 and of the influence of periconceptional glycemic control. METHODS: Multicenter retrospective clinical study, literature review, and meta-analysis. The incidence and pattern of congenital heart disease in the own study population and in the literature on the offspring of type 1 diabetic mothers were compared with the incidence and spectrum of the various cardiovascular defects in the offspring of nondiabetic mothers as registered by EUROCAT Northern Netherlands. Medical records were, in addition, reviewed for HbA(1c) during the 1st trimester. RESULTS: The distribution of congenital heart anomalies in the own diabetic study population was in accordance with the distribution encountered in the literature. This distribution differed considerably from that in the nondiabetic population. Approximately half the cardiovascular defects were conotruncal anomalies. The authors' study demonstrated a remarkable increase in the likelihood of visceral heterotaxia and variants of single ventricle among these patients. As expected, elevated HbA(1c) values during the 1st trimester were associated with offspring fetal cardiovascular defects. CONCLUSION: This study shows an increased likelihood of specific heart anomalies, namely transposition of the great arteries, persistent truncus arteriosus, visceral heterotaxia and single ventricle, among offspring of diabetic mothers. This suggests a profound teratogenic effect at a very early stage in cardiogenesis. The study emphasizes the frequency with which the offspring of diabetes-complicated pregnancies suffer from complex forms of congenital heart disease. Pregnancies with poor 1st-trimester glycemic control are more prone to the presence of fetal heart disease.

Cohort profile: Antiretroviral Therapy Cohort Collaboration (ART-CC).

The advent of effective combination antiretroviral therapy (ART) in 1996 resulted in fewer patients experiencing clinical events, so that some prognostic analyses of individual cohort studies of human immunodeficiency virus-infected individuals had low statistical power. Because of this, the Antiretroviral Therapy Cohort Collaboration (ART-CC) of HIV cohort studies in Europe and North America was established in 2000, with the aim of studying the prognosis for clinical events in acquired immune deficiency syndrome (AIDS) and the mortality of adult patients treated for HIV-1 infection. In 2002, the ART-CC collected data on more than 12,000 patients in 13 cohorts who had begun combination ART between 1995 and 2001. Subsequent updates took place in 2004, 2006, 2008, and 2010. The ART-CC data base now includes data on more than 70,000 patients participating in 19 cohorts who began treatment before the end of 2009. Data are collected on patient demographics (e.g. sex, age, assumed transmission group, race/ethnicity, geographical origin), HIV biomarkers (e.g. CD4 cell count, plasma viral load of HIV-1), ART regimen, dates and types of AIDS events, and dates and causes of death. In recent years, additional data on co-infections such as hepatitis C; risk factors such as smoking, alcohol and drug use; non-HIV biomarkers such as haemoglobin and liver enzymes; and adherence to ART have been collected whenever available. The data remain the property of the contributing cohorts, whose representatives manage the ART-CC via the steering committee of the Collaboration. External collaboration is welcomed. Details of contacts are given on the ART-CC website (www.art-cohort-collaboration.org).

Modelling of bird distribution under complex mediterranean landscape dynamics: open habitat birds and fire (MEDFIRE)

Report for the scientific sojourn at the Simon Fraser University, Canada, from July to September 2007. General context: landscape change during the last years is having significant impacts on biodiversity in many Mediterranean areas. Land abandonment, urbanisation and specially fire are profoundly transforming large areas in the Western Mediterranean basin and we know little on how these changes influence species distribution and in particular how these species will respond to further change in a context of global change including climate. General objectives: integrate landscape and population dynamics models in a platform allowing capturing species distribution responses to landscape changes and assessing impact on species distribution of different scenarios of further change. Specific objective 1: develop a landscape dynamic model capturing fire and forest succession dynamics in Catalonia and linked to a stochastic landscape occupancy (SLOM) (or spatially explicit population, SEPM) model for the Ortolan bunting, a species strongly linked to fire related habitat in the region. Predictions from the occupancy or spatially explicit population Ortolan bunting model (SEPM) should be evaluated using data from the DINDIS database. This database tracks bird colonisation of recently burnt big areas (&50 ha). Through a number of different SEPM scenarios with different values for a number of parameter, we should be able to assess different hypothesis in factors driving bird colonisation in new burnt patches. These factors to be mainly, landscape context (i.e. difficulty to reach the patch, and potential presence of coloniser sources), dispersal constraints, type of regenerating vegetation after fire, and species characteristics (niche breadth, etc).

Productivity, Preferences and UIP deviations in an Open Economy Business Cycle Model

We show that a flex-price two-sector open economy DSGE model can explain the poor degree of international risk sharing and exchange rate disconnect. We use a suite of model evaluation measures and examine the role of (i) traded and non-traded sectors; (ii) financial market incompleteness; (iii) preference shocks; (iv) deviations from UIP condition for the exchange rates; and (v) creditor status in net foreign assets. We find that there is a good case for both traded and non-traded productivity shocks as well as UIP deviations in explaining the puzzles.

The Timing of Asset Trade and Optimal Policy in Dynamic Open Economies

Using a standard open economy DSGE model, it is shown that the timing of asset trade relative to policy decisions has a potentially important impact on the welfare evaluation of monetary policy at the individual country level. If asset trade in the initial period takes place before the announcement of policy, a national policymaker can choose a policy rule which reduces the work effort of households in the policymaker’s country in the knowledge that consumption is fully insured by optimally chosen international portfolio positions. But if asset trade takes place after the policy announcement, this insurance is absent and households in the policymaker’s country bear the full consumption consequences of the chosen policy rule. The welfare incentives faced by national policymakers are very different between the two cases. Numerical examples confirm that asset market timing has a significant impact on the optimal policy rule.

Balanced Budget Government Spending in a Small Open Regional Economy

This paper investigates the impact of a balanced budget fiscal policy expansion in a regional context within a numerical dynamic general equilibrium model. We take Scotland as an example where, recently, there has been extensive debate on greater fiscal autonomy. In response to a balanced budget fiscal expansion the model suggests that: an increase in current government purchase in goods and services has negative multiplier effects only if the elasticity of substitution between private and public consumption is high enough to move downward the marginal utility of private consumers; public capital expenditure crowds in consumption and investment even with a high level of congestion; but crowding out effects might arise in the short-run if agents are myopic.

A novel device for reducing hemolysis provoked by cardiotomy suction during open heart cardiopulmonary bypass surgery: a randomized prospective study.

Since the inception of cardiopulmonary bypass (CPB), little progress has been made concerning the design of cardiotomy suction (CS). Because this is a major source of hemolysis, we decided to test a novel device (Smartsuction [SS]) specifically aimed at minimizing hemolysis during CPB in a clinical setting. Block randomization was carried out on a treated group (SS, n=28) and a control group (CTRL, n=26). Biochemical parameters were taken pre-, peri-, and post CPB and were compared between the two groups using the Student's t-test with statistical significance when P<0.05. No significant differences in patient demographics were observed between the two groups. Lactate dehydrogenase (LDH) and plasma free hemoglobin (PFH) pre-CPB were comparable for the CTRL and SS groups, respectively. LDH peri-CPB was 275+/-100 U/L versus 207+/-83 U/L for the CTRL and SS groups, respectively (P<0.05). PFH was 486+/-204 mg/L versus 351+/-176 mg/L for the CTRL and SS groups, respectively (P<0.05). LDH post CPB was 354+/-116 U/L versus 275+/-89 U/L for the CTRL and SS groups, respectively (P<0.05). PFH was 549+/-271 mg/L versus 460+/-254 mg/L for the CTRL and SS groups, respectively (P<0.05). Preoperative hematocrit (Hct) of 43+/-5% (CTRL) versus 37+/-5% (SS), and hemoglobin (Hb) of 141+/-16 g/L (CTRL) versus 122+/-17 g/L (SS) were significantly lower in the SS group. However, when normalized (N), the SS was capable of conserving Hct, Hb, and erythrocyte count perioperatively. Erythrocytes (N) were 59+/-5% (CTRL) versus 67+/-9% (SS); Hct (N) was 59+/-6% (CTRL) versus 68+/-9% (SS), and Hb (N) was 61+/-6% (CTRL) versus 70+/-10% (SS) (all P<0.05). This novel SS device evokes significantly lowered blood PFH and LDH values peri- and post CPB compared with the CTRL blood using a CS system. The SS may be a valuable alternative compared to traditional CS techniques.

How much does a single graduation cohort from further education colleges contribute to an open regional economy?

Econometric analysis has been inconclusive in determining the contribution that increased skills have on macroeconomic performance whilst conventional growth accounting approaches to the same problem rest on restrictive assumptions. We propose an alternative micro-to-macro method which combines elements of growth accounting and numerical general equilibrium modelling. The usefulness of this approach for applied education policy analysis is demonstrated by evaluating the macroeconomic impact on the Scottish economy of a single graduation cohort from further education colleges. We find the macroeconomic impact to be significant. From a policy point of view this supports a revival of interest in the conventional teaching role of education institutions.

An investigation of the determinants of household demand for bushmeat in the Serengeti using an open-ended choice experiment

Illegal hunting for bushmeat is regarded as an important cause of biodiversity decline in Africa. We use a stated preferences method to obtain information on determinants of demand for bushmeat in villages around the Serengeti National Park, Tanzania. We estimate the effects of changes in the own price of bushmeat and in the prices of two substitute protein sources – fish and chicken. Promoting the availability of protein substitutes at lower prices would be effective at reducing pressures on wildlife. Supply-side measures that raise the price of bushmeat would also be effective.