Schistosomiasis control in a primary health care system

The successful implementation of a Primary Health Care System (PHC) in any country depends primarily on the ability to adapt its concepts and principles to the country's culture and development stage. Thus, the PHC system should reflect a balanced interaction between available resources, such as health manpower capabilities, and the nature and magnitude of the health problems. In addition, PHC should be viewed as the inlet to a multi-level pyramidal health system which caters to both community and individual needs in a balanced way. The adage that Ministries of Health should "work with and for the people" in health development, is especially true in the area of PHC, and hence, the health policy should aim to integrate health services in community development and involve people in its planning, implementation and evaluation.

Self-identity and religion/spirituality

Although medicine is practised in a secular setting, religious and spiritual issues have an impact on patient perspectives regarding their health and the management of any disorders that may afflict them. This is especially true in psychiatry, as feelings of spirituality and religiousness are very prevalent among the mentally ill. Clinicians are rarely aware of the importance of religion and understand little of its value as a mediating force for coping with mental illness. This book addresses various issues concerning mental illness in psychiatry: the relation of religious issues to mental health; the tension between a theoretical approach to problems and psychiatric approaches; the importance of addressing these varying approaches in patient care and how to do so; and differing ways to approach Christian, Muslim, and Buddhist patients. This is the first book to specifically cover the impact of religion and spirituality on mental illness.

Turning sunlight into stone: the oxalate-carbonate pathway in a tropical tree ecosystem.

An African oxalogenic tree, the iroko tree (Milicia excelsa), has the property to enhance carbonate precipitation in tropical oxisols, where such accumulations are not expected due to the acidic conditions in these types of soils. This uncommon process is linked to the oxalate-carbonate pathway, which increases soil pH through oxalate oxidation. In order to investigate the oxalate-carbonate pathway in the iroko system, fluxes of matter have been identified, described, and evaluated from field to microscopic scales. In the first centimeters of the soil profile, decaying of the organic matter allows the release of whewellite crystals, mainly due to the action of termites and saprophytic fungi. In addition, a concomitant flux of carbonate formed in wood tissues contributes to the carbonate flux and is identified as a direct consequence of wood feeding by termites. Nevertheless, calcite biomineralization of the tree is not a consequence of in situ oxalate consumption, but rather related to the oxalate oxidation inside the upper part of the soil. The consequence of this oxidation is the presence of carbonate ions in the soil solution pumped through the roots, leading to preferential mineralization of the roots and the trunk base. An ideal scenario for the iroko biomineralization and soil carbonate accumulation starts with oxalatization: as the iroko tree grows, the organic matter flux to the soil constitutes the litter, and an oxalate pool is formed on the forest ground. Then, wood rotting agents (mainly termites, saprophytic fungi, and bacteria) release significant amounts of oxalate crystals from decaying plant tissues. In addition, some of these agents are themselves producers of oxalate (e.g. fungi). Both processes contribute to a soil pool of "available" oxalate crystals. Oxalate consumption by oxalotrophic bacteria can then start. Carbonate and calcium ions present in the soil solution represent the end products of the oxalate-carbonate pathway. The solution is pumped through the roots, leading to carbonate precipitation. The main pools of carbon are clearly identified as the organic matter (the tree and its organic products), the oxalate crystals, and the various carbonate features. A functional model based on field observations and diagenetic investigations with δ13C signatures of the various compartments involved in the local carbon cycle is proposed. It suggests that the iroko ecosystem can act as a long-term carbon sink, as long as the calcium source is related to non-carbonate rocks. Consequently, this carbon sink, driven by the oxalate carbonate pathway around an iroko tree, constitutes a true carbon trapping ecosystem as defined by ecological theory.

On problems of calculating energy expenditure and substrate utilization from respiratory exchange data.

Indirect calorimetry based on respiratory exchange measurement has been successfully used from the beginning of the century to obtain an estimate of heat production (energy expenditure) in human subjects and animals. The errors inherent to this classical technique can stem from various sources: 1) model of calculation and assumptions, 2) calorimetric factors used, 3) technical factors and 4) human factors. The physiological and biochemical factors influencing the interpretation of calorimetric data include a change in the size of the bicarbonate and urea pools and the accumulation or loss (via breath, urine or sweat) of intermediary metabolites (gluconeogenesis, ketogenesis). More recently, respiratory gas exchange data have been used to estimate substrate utilization rates in various physiological and metabolic situations (fasting, post-prandial state, etc.). It should be recalled that indirect calorimetry provides an index of overall substrate disappearance rates. This is incorrectly assumed to be equivalent to substrate "oxidation" rates. Unfortunately, there is no adequate golden standard to validate whole body substrate "oxidation" rates, and this contrasts to the "validation" of heat production by indirect calorimetry, through use of direct calorimetry under strict thermal equilibrium conditions. Tracer techniques using stable (or radioactive) isotopes, represent an independent way of assessing substrate utilization rates. When carbohydrate metabolism is measured with both techniques, indirect calorimetry generally provides consistent glucose "oxidation" rates as compared to isotopic tracers, but only when certain metabolic processes (such as gluconeogenesis and lipogenesis) are minimal or / and when the respiratory quotients are not at the extreme of the physiological range. However, it is believed that the tracer techniques underestimate true glucose "oxidation" rates due to the failure to account for glycogenolysis in the tissue storing glucose, since this escapes the systemic circulation. A major advantage of isotopic techniques is that they are able to estimate (given certain assumptions) various metabolic processes (such as gluconeogenesis) in a noninvasive way. Furthermore when, in addition to the 3 macronutrients, a fourth substrate is administered (such as ethanol), isotopic quantification of substrate "oxidation" allows one to eliminate the inherent assumptions made by indirect calorimetry. In conclusion, isotopic tracers techniques and indirect calorimetry should be considered as complementary techniques, in particular since the tracer techniques require the measurement of carbon dioxide production obtained by indirect calorimetry. However, it should be kept in mind that the assessment of substrate oxidation by indirect calorimetry may involve large errors in particular over a short period of time. By indirect calorimetry, energy expenditure (heat production) is calculated with substantially less error than substrate oxidation rates.

Crazy ideas ?

Review of the book : "Nine crazy ideas in Science: a few might even be true", by R. Ehrlich, Princeton University Press, New-Jersey

Individualització de la programació docent de Fonaments de Computadors

La metodologia docent impulsada per la creació d’un Espai Europeu d’Ensenyament Superior comú implica tenir en compte el treball de l’estudiant. En aquest sentit, resulta molt convenient facilitar a l’alumnat de primers cursos l’adaptació a una docència que s’organitza en crèdits ECTS i que se centra en el procés d’aprenentatge dels estudiants. Per aquest motiu, l’objectiu d’aquest projecte ha estat que assumissin un grau més elevat de responsabilitat en l’aprenentatge i que adquirissin una competència més gran en l’organització del temps d’acord amb els programes docents de les assignatures que cursessin. Per aconseguir-ho, s’ha creat un entorn de presentació de les guies docents basat en les agendes d’activitats d’aprenentatge. Aquestes agendes són, de fet, planificacions de les activitats presencials i no presencials que han de dur a terme els estudiants per assolir els objectius de cadascuna de les assignatures que fan. Perquè siguin efectives, han de ser el més individuals possibles i amb la informació suficient com perquè les activitats es puguin dur a terme. Així, els alumnes disposen d’una veritable agenda particular del què han de fer i quan per seguir una assignatura determinada. Com a resultat del projecte s’ha proposat una organització de la informació d’una assignatura que facilita tant la gestió de les guies docents com la creació d’agendes d’activitats d’aprenentatge, s’ha establert una metodologia de presentació dels programes docents amb suport de web perquè sigui de fàcil consulta i en els que els vincles de cada activitat s’activen segons el ritme del curs i, finalment, s’ha aplicat tot per al cas de l’assignatura de Fonaments de computadors, aconseguint que l’alumnat s’acostumi a seguir les agendes d’activitats i, consegüentment, a millorar el rendiment acadèmic de l’assignatura, que era el que, es pretenia originalment.

Pseudomarkets with priorities in large random assignment economies

I study large random assignment economies with a continuum of agents and a finite number of object types. I consider the existence of weak priorities discriminating among agents with respect to their rights concerning the final assignment. The respect for priorities ex ante (ex-ante stability) usually precludes ex-ante envy-freeness. Therefore I define a new concept of fairness, called no unjustified lower chances: priorities with respect to one object type cannot justify different achievable chances regarding another object type. This concept, which applies to the assignment mechanism rather than to the assignment itself, implies ex-ante envy-freeness among agents of the same priority type. I propose a variation of Hylland and Zeckhauser' (1979) pseudomarket that meets ex-ante stability, no unjustified lower chances and ex-ante efficiency among agents of the same priority type. Assuming enough richness in preferences and priorities, the converse is also true: any random assignment with these properties could be achieved through an equilibrium in a pseudomarket with priorities. If priorities are acyclical (the ordering of agents is the same for each object type), this pseudomarket achieves ex-ante efficient random assignments.

Tax evasion, technology shocks, and the cyclicality of government revenues

This paper analyzes the behavior of the tax revenue to output ratio over the business cycle. In order to replicate the empirical evidence, we develop a simple model combining the standard Ak growth model with the tax evasion phenomenon. When individuals conceal part of their true income from the tax authority, they face the risk of being audited and hence of paying the corresponding fine. Under the empirically plausible assumptions that the intertemporal elasticity of substitution exhibits a sufficiently small value and that productivity shocks are serially correlated, we show that the elasticity of government revenue with respect to output is larger than one, which agrees with the empirical evidence. This result holds even if the tax system displays flat tax rates. We extend the previous setup to generate larger fiscal deficits when the economy experiences a recession.

Anàlisi del sistema agroecològic de Vila-seca: proposta de guia per a la descoberta del medi

S’ha elaborat una anàlisi del sistema agroecològic del municipi de Vila-seca (Tarragonès) per tal de realitzar en segon lloc, una proposta de guia per a la descoberta del medi per a infants d’entre 8 i 10 anys. A partir del treball de camp realitzat a la zona d’estudi s’han inventariat diferents elements del patrimoni socioecològic que es consideren de rellevada importància al terme. Entre ells destaquen oliveres, garrofers, avellaners, arbres singulars, masos, basses, marges de pedra seca i trones, els quals s’integren en el medi formant un veritable sistema agroecològic, fruit de la interacció entre vectors biofísics i socioeconòmics. D’altra banda, per tal de donar a conèixer aquest sistema s’ha realitzat una proposta de descoberta del medi agrícola a partir d’un itinerari d’educació ambiental per la zona estudiada, on s’engloben tots aquells elements d’especial interès en un recorregut de 2,9 quilòmetres. La guia disposa a més d’una sèrie d’activitats a realitzar a l’entorn per tal de motivar el sentiment de descoberta d’aquest sistema. D’aquesta manera, considerant les fortes pressions que aquest territori pateix per part de les infraestructures i les urbanitzacions és destriable la necessitat de conservació i l’addició dels elements inventariats al catàleg del Patrimoni del municipi.

A conceptual framework to assess the effectiveness of HIV prevention

Aim: The relative effectiveness of different methods of prevention of HIV transmission is a subject of debate that is renewed with the integration of each new method. The relative weight of values and evidence in decision-making is not always clearly defined. Debate is often confused, as the proponents of different approaches address the issue at different levels of implementation. This paper defines and delineates the successive levels of analysis of effectiveness, and proposes a conceptual framework to clarify debate. Method / Issue: Initially inspired from work on contraceptive effectiveness, a first version of the conceptual framework was published in 1993 with definition of the Condom Effectiveness Matrix (Spencer, 1993). The framework has since integrated and further developed thinking around distinctions made between efficacy and effectiveness and has been applied to HIV prevention in general. Three levels are defined: theoretical effectiveness (ThE), use-effectiveness (UseE) and population use-effectiveness (PopUseE). For example, abstinence and faithfulness, as proposed in the ABC strategy, have relatively high theoretical effectiveness but relatively low effectiveness at subsequent levels of implementation. The reverse is true of circumcision. Each level is associated with specific forms of scientific enquiry and associated research questions: basic and clinical sciences with ThE; clinical and social sciences with UseE; epidemiology and social, economic and political sciences with PopUseE. Similarly, the focus of investigation moves from biological organisms, to the individual at the physiological and then psychological, social and ecological level, and finally takes as perspective populations and societies as a whole. The framework may be applied to analyse issues on any approach. Hence, regarding consideration of HIV treatment as a means of prevention, examples of issues at each level would be: ThE: achieving adequate viral suppression and non-transmission to partners; UseE: facility and degree of adherence to treatment and medical follow-up; PopUseE: perceived validity of strategy, feasibility of achieving adequate population coverage. Discussion: Use of the framework clarifies the questions that need to be addressed at all levels in order to improve effectiveness. Furthermore, the interconnectedness and complementary nature of research from the different scientific disciplines and the relative contribution of each become apparent. The proposed framework could bring greater rationality to the prevention effectiveness debate and facilitate communication between stakeholders.

Consistency and optimality

Assume that the problem Qo is not solvable in polynomial time. For theories T containing a sufficiently rich part of true arithmetic we characterize T U {ConT} as the minimal extension of T proving for some algorithm that it decides Qo as fast as any algorithm B with the property that T proves that B decides Qo. Here, ConT claims the consistency of T. Moreover, we characterize problems with an optimal algorithm in terms of arithmetical theories.

Mitotic figure counts are significantly overestimated in resection specimens of invasive breast carcinomas.

Several authors have demonstrated an increased number of mitotic figures in breast cancer resection specimen when compared with biopsy material. This has been ascribed to a sampling artifact where biopsies are (i) either too small to allow formal mitotic figure counting or (ii) not necessarily taken form the proliferating tumor periphery. Herein, we propose a different explanation for this phenomenon. Biopsy and resection material of 52 invasive ductal carcinomas was studied. We counted mitotic figures in 10 representative high power fields and quantified MIB-1 immunohistochemistry by visual estimation, counting and image analysis. We found that mitotic figures were elevated by more than three-fold on average in resection specimen over biopsy material from the same tumors (20±6 vs 6±2 mitoses per 10 high power fields, P=0.008), and that this resulted in a relative diminution of post-metaphase figures (anaphase/telophase), which made up 7% of all mitotic figures in biopsies but only 3% in resection specimen (P<0.005). At the same time, the percentages of MIB-1 immunostained tumor cells among total tumor cells were comparable in biopsy and resection material, irrespective of the mode of MIB-1 quantification. Finally, we found no association between the size of the biopsy material and the relative increase of mitotic figures in resection specimen. We propose that the increase in mitotic figures in resection specimen and the significant shift towards metaphase figures is not due to a sampling artifact, but reflects ongoing cell cycle activity in the resected tumor tissue due to fixation delay. The dwindling energy supply will eventually arrest tumor cells in metaphase, where they are readily identified by the diagnostic pathologist. Taken together, we suggest that the rapidly fixed biopsy material better represents true tumor biology and should be privileged as predictive marker of putative response to cytotoxic chemotherapy.

Effects of neuropeptide Y on intrarenal hemodynamics, plasma renin activity and urinary sodium excretion in rats.

Neuropeptide Y (NPY) is a vasoconstrictor peptide possibly involved in the regulation of renal sodium handling and renin release. This investigation was undertaken to assess in conscious normotensive rats the acute effects of a non-pressor dose of NPY on renal plasma flow, glomerular filtration rate, sodium excretion and plasma renin activity. Experiments were also performed during concomitant beta-adrenoceptor stimulation with isoproterenol. NPY per se had no effect on the studied parameters. Renal plasma flow was increased by isoproterenol and was significantly higher when the beta-adrenoceptor stimulant was infused alone (13.4 +/- 2.1 ml/min, p < 0.05, mean +/- SEM) that when administered together with NPY (7.2 +/- 2.0 ml/min). This was also true for glomerular filtration rate (3.3 +/- 0.3 vs. 1.8 +/- 0.3 ml/min, p < 0.01) and plasma renin activity (6.3 +/- 1.7 vs. 2.1 +/- 0.4 ng Ang I/ml/h, p < 0.05). Our data however do not allow to deduce whether the inhibitory effect of NPY on isoproterenol-induced renin release is mediated by changes in intrarenal hemodynamics or a direct effect on juxtaglomerular cells.

Illicit drug profiling, reflection on statistical comparisons

This paper presents reflexions about statistical considerations on illicit drug profiling and more specifically about the calculation of threshold for determining of the seizure are linked or not. The specific case of heroin and cocaine profiling is presented with the necessary details on the target profiling variables (major alkaloids) selected and the analytical method used. Statistical approach to compare illicit drug seizures is also presented with the introduction of different scenarios dealing with different data pre-treatment or transformation of variables.The main aim consists to demonstrate the influence of data pre-treatment on the statistical outputs. A thorough study of the evolution of the true positive rate (TP) and the false positive rate (FP) in heroin and cocaine comparison is then proposed to investigate this specific topic and to demonstrate that there is no universal approach available and that the calculations have to be revaluate for each new specific application.

Quantitative phenetics and taxonomy of some phlebotomine taxa

Elucidating the evolution of Phlebotominae is important not only to revise their taxonomy, but also to help understand the origin of the genus Leishmania and its relationship with humans. Our study is a phenetic portrayal of this history based on the genetic relationships among some New Word and Old Word taxa. We used both multilocus enzyme electrophoresis and morphometry on 24 male specimens of the Old Word genus Phlebotomus (with three of its subgenera: Phlebotomus, Spelaeophlebotomus and Australophlebotomus), and on 67 male specimens of the three New World genera, Warileya, Brumptomyia and Lutzomyia, (with three subgenera of Lutzomyia: Lutzomyia, Oligodontomyia and Psychodopygus). Phenetic trees derived from both techniques were similar, but disclosed relationships that disagree with the present classification of sand flies. The need for a true evolutionary approach is stressed.