Community-based health insurance and social protection policy

Of all the risks facing poor households, health risks pose the greatest threat to their lives and livelihoods. A health shock adds health expenditures to the burden of the poor precisely at the time when they can afford it the least.One of the ways that poor communities manage health risks, in combination with publicly financed health care services, are community-based health insurance schemes (CBHIs). These are small scale, voluntary health insurance programs, organized and managed in a participatory manner. They are designed to be simple and affordable, and to draw on resources of social solidarity and cohesion to overcome problems of small risk pools, moral hazard, fraud, exclusion and cost-escalation. Less than 10 percent of the informal sector population in the developing nations has health coverage from a CBHI, but the number of such schemes is growing rapidly. On average, CBHIs recover between a quarter to a half of health service costs. As a social protection device, they have been shown to be effective in reducing out-of-pocket payments of their members, and in improving access to health services. Many schemes do fail. Problems, such as weak management, poor quality government health services, and the limited resources that local population can mobilize to finance health care, can impede success.Health Economics&Finance,Health Monitoring&Evaluation,Poverty Assessment,Safety Nets and Transfers,Insurance&Risk Mitigation

Pharmacological analysis of ionotropic glutamate and GABA recptor function in neuronal circuits of the zebrafish olfactory bulb

In the olfactory bulb and other brain areas, basic cellular and synaptic properties of individual neurons have been studied extensively in reduced preparations. Nevertheless, it is still poorly understood how intactions between multiple neurons shape spatio-temporal activity patterns and give rise to the computational properties of the the intact circuit. In this thesis, I used pharmacological manipulations of excitatory and inhibitory neurotransmitter receptors to examine the synaptic interactions underlying spontaneous and odor-evoked activity patterns in the intact olfactory bulb of zebrafish. Electrophysiological and one- and two-photon calcium imaging methods were used to record activity from the principal neurons of the OB (mitral cells, MCs), their sensory input, and local interneurons. The combined blockade of AMPA/kainate and NMDA receptors abolished odor-evoked excitation of MCs, indicating that sensory input to the OB is mediated by ionotropic glutamate receptors. Surprisingly, however, the blockade of AMPA/Kainiate receptors alone increased the mean response of MCs and decreased the mean response of interneurons (INs), and the blockade of NMDA receptors caused little or no change in the mean responses of MCs and INs. In addition, antagonists of both glutamate receptor types had diverse effects on the magnitude and time course of individual MC and IN responses and, thus, changed spatio-temporal activity patterns across neuronal populations. The blockade of GABA(A) receptors increased spontaneous and odor evoked firing rates of mitral cells and often induced rhythmic bursting. Moreover, the blockade of, GABA(A) or AMPA/kainate receptors abolished fast oscillatory activity in the local field potential. Blockade of GABA(B) receptors reduced calcium influx in afferent sensory axons and modulated response time courses of mitral cells. These results indicate that (1) IN activity during an odor response depends mainly on AMPA/Kainiate receptor input, (2) interactions between MCs and INs regulate the total OB output activity, (3) AMPA/Kainiate receptors and GABA(A) receptors underly the synchronization of odor-dependent neuronal ensembles and (4) odor-specific patterns of OB output activity are shaped by circuits containing iGlu receptors and GABA receptors. These results provide insights into the mechanisms underlying the processing of odor-encoding activity patterns in the OB.Im olfaktorischen Bulbus (OB) und anderen Hirnarealen wurden grundlegende zelluläre und synaptische Eigenschaften der Einzelneurone ausführlich in reduzierten Präparaten studiert. Trotzdem ist kaum bekannt, wie die Interaktionen mehrerer Nervenzellen untereinander räumlich-zeitlich strukturierte Aktivitätsmuster formen und dadurch die rechnerischen Eigenschaften der intakten Schaltkreise entstehen. In dieser Arbeit nutzte ich pharmakologische Manipulationen der erregenden und hemmenden Neurotransmitter-Rezeptoren, um die synaptischen Interaktionen zu untersuchen, die spontanen und geruchsinduzierten Aktivitätsmustern im intakten OB des Zebrafisch zugrunde liegen. Methoden der Elektrophysiology sowie der konventionellen und Zwei-Photonen-Mikroskopie wurden genutzt, um Aktivität von Ausgangsneuronen des OB (Mitralzellen, MCs), ihrem sensorischen Eingang, und Interneuronen (INs) zu messen. Die gleichzeitige Blockierung von AMPA/Kainate- und NMDA-Rezeptoren verhinderte die geruchsinduzierte Erregung von MCs, was darauf hinweist, dass der sensorische Eingang des OB durch ionotrope Glutamatrezeptoren vermittelt wird. Die Blockierung von AMPA/Kainate Rezeptoren allein jedoch erhöhte überraschender Weise im Mittel die Antwort von MCs und reduzierte im Mittel die Antwort von INs. Die Blockierung von NMDA Rezeptoren allein lösten im Mittel geringe oder keine Veränderung der Antworten von MCs and INs aus. Außerdem hatten die Antagonisten für beide Glutamatrezeptoren unterschiedliche Einflüsse auf Größe und Zeitverlauf individueller MC- und IN- Antworten und veränderten daher das räumlich-zeitliche Aktivitätsmuster innerhalb der Nervenzellpopulation. Die Blockierung von GABA(A)-Rezeptoren erhöhte spontane und geruchsinduzierte Feuerraten in MCs und induzierten oft rhythmische, stoßweise Aktivität. Die Blockierung von GABA(A)- und AMPA/Kainate-Rezeptoren hob überdies geruchsinduzierte Oszillationen im Feldpotenzial auf. Die Blockierung von GABA(B)-Rezeptoren verringerte den Kalziumeinstrom in die Endigungen afferenter sensorischer Axone und modulierte den Zeitverlauf von MC-Antworten. Die Ergebnisse zeigen, dass (1) die Aktivität der Interneurone während der Geruchsantwort hauptsächlich von AMPA/Kainate-Rezeptoren abhängt, (2) die Interaktionen zwischen Mitralzellen und Interneuronen die Gesamtaktivität des Ausgangssingnales des olfaktorischen Bulbus regulieren, (3) AMPA/Kainate-Rezeptoren und GABA(A)-Rezeptoren der Synchronisation geruchsabhängiger Gruppen von Nervenzellen zugrunde liegen und (4) geruchsspezifische Muster im Ausgangssignal des olfaktorischen Bulbus durch Schaltkreise geformt werden, die iGlu Rezeptoren und GABA Rezeptoren enthalten. Diese Ergebnisse ermöglichen Einblick in die Mechanismen die der Verarbeitung geruchskodierender Aktivitätsmuster im olfaktorischen Bulbus unterliegen

Photogeologic interpretation of Gemini 4 color photography - Baja, California

Photogeologic interpretation of Gemini 4 color photographs of Baja, Californi

Transport in Almost Integrable Models: Perturbed Heisenberg Chains

The heat conductivity kappa(T) of integrable models, like the one-dimensional spin-1/2 nearest-neighbor Heisenberg model, is infinite even at finite temperatures as a consequence of the conservation laws associated with integrability. Small perturbations lead to finite but large transport coefficients which we calculate perturbatively using exact diagonalization and moment expansions. We show that there are two different classes of perturbations. While an interchain coupling of strength J_perp leads to kappa(T) propto 1/J_perp^2 as expected from simple golden-rule arguments, we obtain a much larger kappa(T) propto 1/J'^4 for a weak next-nearest neighbor interaction J'. This can be explained by a new approximate conservation law of the J-J' Heisenberg chain.Comment: 4 pages, several minor modifications, title change

Neolithic pits at Cadbury Castle and an adjacent occupation site at Milsom’s Corner, South Cadbury

During five seasons of excavations directed by Leslie Alcock from 1966 to 1970 on the multiperiod hillfort at South Cadbury Castle, Somerset, England proven and possible Early Neolithic postholes and pits were identified in several trenches on the plateau, under the southern inner bank and bisected by the Iron Age South West gate passage. A discrete assemblage of Late Neolithic material was discovered under the north bank. The evidence has been treated only cursorily in a popular account of the excavations and in the final reports which focused on the periods following 1000 BC (Alcock 1972, 1995; Barrett et al. 2000). Subsequent excavations from 1995 to 1999 by the South Cadbury Environs Project on a spur outside the western ramparts exposed an Early Neolithic occupation hollow and four contemporary pits. There were notable differences in the pottery, bone and worked stone assemblages between the hilltop and on the spur. This paper presents fully for the first time the evidence from the two South Cadbury sites. It considers their place in the Early Neolithic with respect to the better known sites of the period in Wessex and the south west peninsula and takes in recent evidence from both research and development-led projects in eastern England and elsewhere. The well-dated palimpsest from Milsoms Corner is an important contribution to our understanding of day-to-day life at a temporary occupation site and to the topical debate concerning deposit formation in Neolithic pits