Testing for sufficient information in structural VARs

We derive necessary and sufficient conditions under which a set of variables is informationally sufficient, i.e. it contains enough information to estimate the structural shocks with a VAR model. Based on such conditions, we suggest a procedure to test for informational sufficiency. Moreover, we show how to amend the VAR if informational sufficiency is rejected. We apply our procedure to a VAR including TFP, unemployment and per-capita hours worked. We find that the three variables are not informationally sufficient. When adding missing information, the effects of technology shocks change dramatically.

Time and temperature dependant changes in red blood cell analytes used for testing recombinant erythropoietin abuse in sports.

There has been a long debate since the introduction of blood analysis prior to major sports events, to find out whether blood samples should be analysed right away on the site of competition or whether they should be transported and analysed in an anti-doping laboratory. Therefore, it was necessary to measure blood samples and compare the results obtained right after the blood withdrawal with those obtained after a few hours delay. Furthermore, it was interesting to determine the effect of temperature on the possible deterioration of red blood cell analytes used for testing recombinant erythropoietin abuse. Healthy volunteers were asked to give two blood samples and one of these was kept at room temperature whereas the second one was put into a refrigerator. On a regular basis, the samples were rolled for homogenisation and temperature stabilisation and were analysed with the same haematological apparatus. The results confirmed that blood controls prior to competition should be performed as soon as possible with standardised pre-analytical conditions to avoid too many variations notably on the haematocrit and the reticulocyte count. These recommendations should ideally also be applied to the all the blood controls compulsory for the medical follow up, otherwise unexplainable values could be misinterpreted and could for instance lead to a period of incapacity.

Clinical benefits of an adherence monitoring program in the management of secondary hyperparathyroidism with cinacalcet: results of a prospective randomized controlled study.

BACKGROUND/AIMS: One of the causes of uncontrolled secondary hyperparathyroidism (sHPT) is patient's poor drug adherence. We evaluated the clinical benefits of an integrated care approach on the control of sHPT by cinacalcet. METHODS: Prospective, randomized, controlled, multicenter, open-label study. Fifty hemodialysis patients on a stable dose of cinacalcet were randomized to an integrated care approach (IC) or usual care approach (UC). In the IC group, cinacalcet adherence was monitored using an electronic system. Results were discussed with the patients in motivational interviews, and drug prescription adapted accordingly. In the UC group, drug adherence was monitored, but results were not available. RESULTS: At six months, 84% of patients in the IC group achieved recommended iPTH targets versus 55% in the UC group (P = 0.04). The mean cinacalcet taking adherence improved by 10.8% in the IC group and declined by 5.3% in the UC group (P = 0.02). Concomitantly, the mean dose of cinacalcet was reduced by 7.2 mg/day in the IC group and increased by 6.4 mg/day in the UC group (P = 0.03). CONCLUSIONS: The use of a drug adherence monitoring program in the management of sHPT in hemodialysis patients receiving cinacalcet improves drug adherence and iPTH control and allows a reduction in the dose of cinacalcet.

Same wording, distinct concepts? Testing differences between expectancies and motives in a mediation model of alcohol outcomes.

Per definition, alcohol expectancies (after alcohol I expect X), and drinking motives (I drink to achieve X) are conceptually distinct constructs. Theorists have argued that motives mediate the association between expectancies and drinking outcomes. Yet, given the use of different instruments, do these constructs remain distinct when assessment items are matched? The present study tested to what extent motives mediated the link between expectancies and alcohol outcomes when identical items were used, first as expectancies and then as motives. A linear structural equation model was estimated based on a national representative sample of 5,779 alcohol-using students in Switzerland (mean age = 15.2 years). The results showed that expectancies explained up to 38% of the variance in motives. Together with motives, they explained up to 48% of the variance in alcohol outcomes (volume, 5+ drinking, and problems). In 10 of 12 outcomes, there was a significant mediated effect that was often higher than the direct expectancy effect. For coping, the expectancy effect was close to zero, indicating the strongest form of mediation. In only one case (conformity and 5+ drinking), there was a direct expectancy effect but no mediation. To conclude, the study demonstrates that motives are distinct from expectancies even when identical items are used. Motives are more proximally related to different alcohol outcomes, often mediating the effects of expectancies. Consequently, the effectiveness of interventions, particularly those aimed at coping drinkers, should be improved through a shift in focus from expectancies to drinking motives.

Automatización de testing

El objetivo del proyecto es el desarrollo de una herramienta de trabajo para un departamento de Calidad. A través de ella, se deben poder ejecutar unos test automatizados sobre unas funcionalidades que tiene la aplicación Logic Class: el Cálculo de Nómina y Seguros Sociales.

In vivo testing of a novel adjustable glaucoma drainage device.

PURPOSE: We report on the in vivo testing of a novel noninvasively adjustable glaucoma drainage device (AGDD), which features an adjustable outflow resistance, and assess the safety and efficiency of this implant. METHODS: Under general anesthesia, the AGDD was implanted on seven white New Zealand rabbits for a duration of 4 months under a scleral flap in a way analogous to the Ex-PRESS device and set in an operationally closed position. The IOP was measured on a regular basis on the operated and control eyes using a rebound tonometer. Once a month the AGDD was adjusted noninvasively from its fully closed to its fully open position and the resulting pressure drop was measured. The contralateral eye was not operated and served as control. After euthanization, the eyes were collected for histology evaluation. RESULTS: The mean preoperative IOP was 11.1 ± 2.4 mm Hg. The IOP was significantly lower for the operated eye (6.8 ± 2 mm Hg) compared to the nonoperated eye (13.1 ± 1.6 mm Hg) during the first 8 days after surgery. When opening the AGDD from its fully closed to fully open position, the IOP dropped significantly from 11.2 ± 2.9 to 4.8 ± 0.9 mm Hg (P < 0.05). CONCLUSIONS: Implanting the AGDD is a safe and uncomplicated surgical procedure. The fluidic resistance was noninvasively adjustable during the postoperative period with the AGDD between its fully closed and fully open positions.

Effect of changes in the deuterium content of drinking water on the hydrogen isotope ratio of urinary steroids in the context of sports drug testing.

The hydrogen isotope ratio (HIR) of body water and, therefore, of all endogenously synthesized compounds in humans, is mainly affected by the HIR of ingested drinking water. As a consequence, the entire organism and all of its synthesized substrates will reflect alterations in the isotope ratio of drinking water, which depends on the duration of exposure. To investigate the effect of this change on endogenous urinary steroids relevant to doping-control analysis the hydrogen isotope composition of potable water was suddenly enriched from -50 to 200 0/00 and maintained at this level for two weeks for two individuals. The steroids under investigation were 5β-pregnane-3α,20α-diol, 5α-androst-16-en-3α-ol, 3α-hydroxy-5α-androstan-17-one (ANDRO), 3α-hydroxy-5β-androstan-17-one (ETIO), 5α-androstane-3α,17β-diol, and 5β-androstane-3α,17β-diol (excreted as glucuronides) and ETIO, ANDRO and 3β-hydroxyandrost-5-en-17-one (excreted as sulfates). The HIR of body water was estimated by determination of the HIR of total native urine, to trace the induced changes. The hydrogen in steroids is partly derived from the total amount of body water and cholesterol-enrichment could be calculated by use of these data. Although the sum of changes in the isotopic composition of body water was 150 0/00, shifts of approximately 30 0/00 were observed for urinary steroids. Parallel enrichment in their HIR was observed for most of the steroids, and none of the differences between the HIR of individual steroids was elevated beyond recently established thresholds. This finding is important to sports drug testing because it supports the intended use of this novel and complementary methodology even in cases where athletes have drunk water of different HIR, a plausible and, presumably, inevitable scenario while traveling.

Respiratory muscle training enhances maximal minute ventilation and forced vital capacity in adolescent athletes.

Introduction. Respiratory difficulties in athletes are common, especially in adolescents, even in the absence of exercise-induced bronchoconstriction. Immaturity of the respiratory muscles coupling at high respiratory rates could be a potential mechanism. Whether respiratory muscle training (RMT) can positively influence it is yet unknown. Goal. We investigate the effects of RMT on ventilation and performance parameters in adolescent athletes and hypothesize that RMT will enhance respiratory capacity. Methods. 12 healthy subjects (8 male, 4 female, 17±0.5 years) from a sports/study high school class, competitively involved in various sports (minimum of 10 hours per week) underwent respiratory function testing, maximal minute ventilation (MMV) measurements and a maximal treadmill incremental test with VO2max and ventilatory thresholds (VT1 and VT2) determination. They then underwent one month of RMT (4 times/week) using a eucapnic hyperventilation device, with an incremental training program. The same tests were repeated after RMT. Results. Subjects completed 14.8 sessions of RMT, with an increase in total ventilation per session of 211±29% during training. Borg scale evaluation of the RMT session was unchanged or reduced in all subjects, despite an increase in total respiratory work. No changes (p>0.05) were observed pre/post RMT in VO2max (53.4±7.5 vs 51.6±7.7 ml/kg/min), VT2 (14.4±1.4 vs 14.0±1.1 km/h) or Speed max at end of test (16.1±1.7 vs 15.8±1.7 km/h). MVV increased by 9.2% (176.7±36.9 vs 192.9±32.6 l/min, p<0.001) and FVC by 3.3% (6.70±0.75 vs 4.85±0.76 litres, p<0.05). Subjective evaluation of respiratory sensations during exercise and daily living were also improved. Conclusions. RMT improves MMV and FVC in adolescent athletes, along with important subjective respiratory benefits, although no changes are seen in treadmill maximal performance tests and VO2max measurements. RMT can be easily performed in adolescent without side effects, with a potential for improvement in training capacity and overall well-being.

Antimalarial drug susceptibility testing of Plasmodium falciparum in Brazil using a radioisotope method

From March 1996 to August 1997, a study was carried out in a malaria endemic area of the Brazilian Amazon region. In vivo sensitivity evaluation to antimalarial drugs was performed in 129 patients. Blood samples (0.5 ml) were drawn from each patient and cryopreserved to proceed to in vitro studies. In vitro sensitivity evaluation performed using a radioisotope method was carried out with the cryopreserved samples from September to December 1997. Thirty-one samples were tested for chloroquine, mefloquine, halofantrine, quinine, arteether and atovaquone. Resistance was evidenced in 96.6% (29/30) of the samples tested for chloroquine, 3.3% (1/30) for quinine, none (0/30) for mefloquine and none for halofantrine (0/30). Overall low sensitivity was evidenced in 10% of the samples tested for quinine, 22.5% tested for halofantrine and in 20% tested for mefloquine. Means of IC 50 values were 132.2 (SD: 46.5) ng/ml for chloroquine, 130.6 (SD: 49.6) ng/ml for quinine, 3.4 (SD: 1.3) ng/ml for mefloquine, 0.7 (SD: 0.3) ng/ml for halofantrine, 1 (SD: 0.6) ng/ml for arteether and 0.4 (SD: 0.2) ng/ml for atovaquone. Means of chloroquine IC 50 of the tested samples were comparable to that of the chloroquine-resistant strain W2 (137.57 ng/ml) and nearly nine times higher than that of the chloroquine-sensitive strain D6 (15.09 ng/ml). Means of quinine IC 50 of the tested samples were 1.7 times higher than that of the low sensitivity strain W2 (74.84 ng/ml) and nearly five times higher than that of the quinine-sensitive strain D6 (27.53 ng/ml). These results disclose in vitro high resistance levels to chloroquine, low sensitivity to quinine and evidence of decreasing sensitivity to mefloquine and halofantrine in the area under evaluation.

Simulium spp. control program in Rio Grande do Sul, Brazil

Insects of the Simuliidae family have been the object of control in Rio Grande do Sul since the 70s. Their constant attacks became a social-economical problem as well as a problem of Public Health, with serious consequences to men and to the economy of the areas in which the insects develop. At first, the control was done with a chemical larvicide Themephos ABATE 500 E, but an imperfect measuring of outflow to determine the quantity of the product made Simulium spp. resistant to it. From 1983 on, following a study of a new method for the outflow measuring, we started to use a biological larvicide Bacillus thuringiensis serovar israelensis based. The biological control uses the new method in 36.4% of the state area, assisting about 3,500,000 inhabitants.

Appropriateness of methadone maintenance treatment for opiate addiction: evaluation by an expert panel.

With some 30,000 dependent persons, opiate addiction constitutes a major public health problem in Switzerland. The Swiss Federal Office of Public Health (FOPH) has long played a leading role in the prevention and treatment of opiate addiction and in research on effective means of containing the epidemic of opiate addiction and its consequences. Major milestones on that path have been the successive "Methadone reports" published by that Office and providing guidance on the care of opiate addiction with substitution treatment. In view of updating the recommendations for the appropriateness of substitution treatment for opiate addiction, in particular for the prescription of methadone, the FOPH commissioned a multi-component project involving the following elements. A survey of current attitudes and practices in Switzerland related to opiate substitution treatment Review of Swiss literature on methadone substitution treatment Review of international literature on methadone substitution treatment National Methadone Substitution Conference Multidisciplinary expert panel to evaluate the appropriateness of substitution treatment. The present report documents the process and summarises the results of the latter element above. The RAND appropriateness method (RAM) was used to distil from literature-based evidence and systematically formulated expert opinion, areas where consensus exist on the appropriateness (or inappropriateness) of methadone maintenance treatment (MMT) and areas where disagreement or uncertainty persist and which should be further pursued. The major areas which were addressed by this report are Initial assessment of candidates for MMT Appropriate settings for initiation of MMT (general and special cases) Appropriateness of methadone supportive therapy Co-treatments and accompanying measures Dosage schedules and pharmacokinetic testing Withdrawal from MMT Miscellaneous questions Appropriateness of other (non-methadone) substitution treatment Summary statements for each of the above categories are derived from the panel meeting and presented in the report. In the "first round", agreement was observed for 31% of the 553 theoretical scenarios evaluated. The "second round" rating, following discussion of divergent ratings, resulted in a much higher agreement among panellists, reaching 53% of the 537 scenarios. Frank disagreement was encountered for 7% of all scenarios. Overall 49% of the clinical situations (scenarios) presented were considered appropriate. The areas where at least 50% of the situations were considered appropriate were "initial assessment of candidates for MMT", the "appropriate settings for initiation of MMT", the "appropriate settings for methadone supportive treatment" and "Appropriateness of other (non-methadone) substitution treatment". The area where there was the least consensus on appropriateness concerned "appropriateness of withdrawal from MMT" (6%). The report discusses the implications and limitations of the panel results and provides recommendations for the dissemination, application, and future use of the criteria for the appropriateness of MMT. The RAND Appropriateness Method proved to be an accepted and appreciated method to assess the appropriateness of methadone maintenance treatment for opiate addicts. In the next step, the results of the expert panel process must now be combined with those of the Swiss and international literature reviews and the survey of current attitudes and practices in Switzerland, to be synthesized into formal practice guidelines. Such guidelines should be disseminated to all concerned, promoted, used and rigorously evaluated for compliance and outcome.

Testing kin selection with sex allocation data in eusocial hymenoptera

Sex allocation data in eusocial Hymenoptera (ants, bees and wasps) provide an excellent opportunity to assess the effectiveness of kin selection, because queens and workers differ in their relatedness to females and males. The first studies on sex allocation in eusocial Hymenoptera compared population sex investment ratios across species. Female-biased investment in monogyne (= with single-queen colonies) populations of ants suggested that workers manipulate sex allocation according to their higher relatedness to females than males (relatedness asymmetry). However, several factors may confound these comparisons across species. First, variation in relatedness asymmetry is typically associated with major changes in breeding system and life history that may also affect sex allocation. Secondly, the relative cost of females and males is difficult to estimate across sexually dimorphic taxa, such as ants. Thirdly, each species in the comparison may not represent an independent data point, because of phylogenetic relationships among species. Recently, stronger evidence that workers control sex allocation has been provided by intraspecific studies of sex ratio variation across colonies. In several species of eusocial Hymenoptera, colonies with high relatedness asymmetry produced mostly females, in contrast to colonies with low relatedness asymmetry which produced mostly males. Additional signs of worker control were found by investigating proximate mechanisms of sex ratio manipulation in ants and wasps. However, worker control is not always effective, and further manipulative experiments will be needed to disentangle the multiple evolutionary factors and processes affecting sex allocation in eusocial Hymenoptera.

Avaluació de la tecnologia de les GPUs

En el projecte s’ha dut a terme un estudi sobre la tecnologia que aporten les targetes gràfiques (GPU) dins l’àmbit de programació d’aplicacions que tradicionalment eren executades en la CPU o altrament conegut com a GPGPU. S’ha fet una anàlisi profunda del marc tecnològic actual explicant part del maquinari de les targetes gràfiques i de què tracta el GPGPU. També s’han estudiat les diferents opcions que existeixen per poder realitzar els tests de rendiment que permetran avaluar el programari, quin programari està dissenyat per ser executat amb aquesta tecnologia i quin és el procediment a seguir per poder utilitzar-los. S’han efectuat diverses proves per avaluar el rendiment de programari dissenyat o compatible d’executar en la GPU, realitzant taules comparatives amb els temps de còmput. Un cop finalitzades les diferents proves del programari, es pot concloure que no tota aplicació processada en la GPU aporta un benefici. Per poder veure millores és necessari que l’aplicació reuneixi una sèrie de requisits com que disposi d’un elevat nombre d’operacions que es puguin realitzar en paral lel, que no existeixin condicionants per a l’execució de les operacions i que sigui un procés amb càlcul aritmètic intensiu.