Dispersal of Triatoma infestans and other Triatominae species in the arid Chaco of Argentina: Flying, walking or passive carriage? The importance of walking females

The aim of this paper was to analyse the active dispersal of Triatoma infestans and the role of chickens as passive carriers of this insect in peridomestic areas of La Rioja, Argentina. To measure active dispersal, monthly catches were made on six consecutive nights for five months (in the warm season) using light traps (for flying insects) and sticky dispersal barriers (for walking insects). The nutritional and reproductive states of adults were evaluated. Over the course of the sampling period, a total of eight flying adults, six walking nymphs and 10 walking adults of the species T. infestans were captured, as well as specimens of Triatoma guasayana, Triatoma eratyrusiformis and Triatoma platensis. Our data demonstrate for the first time that females of T. infestans can disperse by walking. This may be an adaptive strategy because it allows them to move with eggs and/or with good blood reserves, which are not possible when flying. All flying and walking individuals of both genders were of an appropriate physiological state that would allow for colonisation of the target habitat. However, manual inspection of 122 chickens suggests that it is unlikely that these animals passively transport T. infestans. Finally, the dispersal activity of T. infestans was compared with other triatomines using a dispersion index.

Passive lipoidal diffusion and carrier-mediated cell uptake are both important mechanisms of membrane permeation in drug disposition.

Recently, it has been proposed that drug permeation is essentially carrier-mediated only and that passive lipoidal diffusion is negligible. This opposes the prevailing hypothesis of drug permeation through biological membranes, which integrates the contribution of multiple permeation mechanisms, including both carrier-mediated and passive lipoidal diffusion, depending on the compound's properties, membrane properties, and solution properties. The prevailing hypothesis of drug permeation continues to be successful for application and prediction in drug development. Proponents of the carrier-mediated only concept argue against passive lipoidal diffusion. However, the arguments are not supported by broad pharmaceutics literature. The carrier-mediated only concept lacks substantial supporting evidence and successful applications in drug development.

Chest physiotherapy using passive expiratory techniques does not reduce bronchiolitis severity: a randomised controlled trial.

Chest physiotherapy (CP) using passive expiratory manoeuvres is widely used in Western Europe for the treatment of bronchiolitis, despite lacking evidence for its efficacy. We undertook an open randomised trial to evaluate the effectiveness of CP in infants hospitalised for bronchiolitis by comparing the time to clinical stability, the daily improvement of a severity score and the occurrence of complications between patients with and without CP. Children <1 year admitted for bronchiolitis in a tertiary hospital during two consecutive respiratory syncytial virus seasons were randomised to group 1 with CP (prolonged slow expiratory technique, slow accelerated expiratory flow, rarely induced cough) or group 2 without CP. All children received standard care (rhinopharyngeal suctioning, minimal handling, oxygen for saturation ≥92%, fractionated meals). Ninety-nine eligible children (mean age, 3.9 months), 50 in group 1 and 49 in group 2, with similar baseline variables and clinical severity at admission. Time to clinical stability, assessed as primary outcome, was similar for both groups (2.9 ± 2.1 vs. 3.2 ± 2.8 days, P = 0.45). The rate of improvement of a clinical and respiratory score, defined as secondary outcome, only showed a slightly faster improvement of the respiratory score in the intervention group when including stethoacoustic properties (P = 0.044). Complications were rare but occurred more frequently, although not significantly (P = 0.21), in the control arm. In conclusion, this study shows the absence of effectiveness of CP using passive expiratory techniques in infants hospitalised for bronchiolitis. It seems justified to recommend against the routine use of CP in these patients.

Resource management research in Passive Optical Networks (PON)

Next Generation Access Networks (NGAN) are the new step forward to deliver broadband services and to facilitate the integration of different technologies. It is plausible to assume that, from a technological standpoint, the Future Internet will be composed of long-range high-speed optical networks; a number of wireless networks at the edge; and, in between, several access technologies, among which, the Passive Optical Networks (xPON) are very likely to succeed, due to their simplicity, low-cost, and increased bandwidth. Among the different PON technologies, the Ethernet-PON (EPON) is the most promising alternative to satisfy operator and user needs, due to its cost, flexibility and interoperability with other technologies. One of the most interesting challenges in such technologies relates to the scheduling and allocation of resources in the upstream (shared) channel. The aim of this research project is to study and evaluate current contributions and propose new efficient solutions to address the resource allocation issues in Next Generation EPON (NG-EPON). Key issues in this context are future end-user needs, integrated quality of service (QoS) support and optimized service provisioning for real time and elastic flows. This project will unveil research opportunities, issue recommendations and propose novel mechanisms associated with the convergence within heterogeneous access networks and will thus serve as a basis for long-term research projects in this direction. The project has served as a platform for the generation of new concepts and solutions that were published in national and international conferences, scientific journals and also in book chapter. We expect some more research publications in addition to the ones mentioned to be generated in a few months.

Irrigation performance and gross water productivity in furrow-irrigated ornamental tree production

In the ornamental plant production region of Girona (Spain), which is one of the largest of its kind in southern Europe, most of the surface is irrigated using wide blocked-end furrows. The objectives of this paper were: (1) to evaluate the irrigation scheduling methods used by ornamental plant producers; (2) to analyse different scenarios inorder to assess how they affect irrigation performance; (3) to evaluate the risk of deep percolation; and (4) to calculategross water productivity. A two-year study in a representative commercial field, planted with Prunus cerasifera ‘Nigra’, was carried out. The irrigation dose applied by the farmers was slightly smaller than the required water dose estimated by the use of two different methods: the first based on soil water content, and the second based on evapotranspiration. Distribution uniformity and application efficiency were high, with mean values above 87%. Soil water contentmeasurements revealed that even at the end of the furrow, where the infiltrated water depth was greatest, more than 90% of the infiltrated water was retained in the shallowest 40 cm of the soil; accordingly, the risk of water loss due to deep percolation was minimal. Gross water productivity for ornamental tree production was € 11.70 m–3, approximately 20 times higher than that obtained with maize in the same region

Passive modernization? the new human development index and its components in Italy’s regions (1871-2007)

The article presents and discusses estimates of social and economic indicators for Italy’s regions in benchmark years roughly from Unification to the present day: life expectancy, education, GDP per capita at purchasing power parity, and the new Human Development Index (HDI). A broad interpretative hypothesis, based on the distinction between passive and active modernization, is proposed to account for the evolution of regional imbalances over the long-run. In the lack of active modernization, Southern Italy converged thanks to passive modernization, i.e., State intervention: however, this was more effective in life expectancy, less successful in education, expensive and as a whole ineffective in GDP. As a consequence, convergence in the HDI occurred from the late XIX century to the 1970s, but came to a sudden halt in the last decades of the XX century.

Développement de l'irrigation et évolution des régimes fonciers dans la région de Gaya (Niger)

Since the mid 90's, international actors as well as governmental actors have raised their interest into the development of irrigation's potential that is still largely unexploited in Niger. It seems all the more interesting as it could answer the needs of a fast growing population (3.3% per year). However, if everyone agrees on the need to development this system, the current implementation triggers questions on the process itself and its side effects. National and international policies on this matter were build upon an historical process through colonial, post-colonial and then the late 1980's neoliberal structures, leading to a business model that reveals a discrepancy between the state logic and the farming one. This business model asks for a high capacity of mobilization of resources unachievable for many, especially when they want to address small-scale irrigation (area irrigation and the evolution of land tenure systems. The empirical analysis raise three main questions that concern the issue of secure land rights through the modern law, the commoditization of land and land access for the producers. The department of Gaya has a large potential of accessible water resources that allowed an extensive production of fruits and vegetables since the 1980's. These productions were developed at first by the local farmers, but the high value added engendered then attracted external players as well, such as civil servants and merchants. The World Bank supported this momentum through the development of a business type project. Unfortunately, it reached mostly the new external players and local elites rather than the small farmers, notably due to the high illiteracy rate among farmers. In terms of land tenure analysis, the project excluded all farmers cultivating land on a loan or lease agreement and all those for whom it was difficult to obtain a title of ownership. However, this new interest for small-scale irrigation exerted by the project and the new players triggered the commoditization of land. As a matter of fact, the demographic constraints and the fragmentation of the familial land ownership led to a more individual production system, where the customary relation to land tenure is weakened or even overcome. This makes it easier for the new players who need to settle their small-scale irrigation projects to purchase land. When there are only few areas available for selling, the. purchasing processes are undermining the farmers with insecure rights. If the withdrawal of lands is supposed to be smoothened by social measures, such as replacement of the land and primary offers to purchase the land, those measures are often not attractive. The proposed land of replacement is frequently too far away located or lesser fertile to be of any use and the economic capacity of purchasing is too little, eventually leading the farmers to leave their terroirs. Those in charge of the application of the Rural Code have succeeding in answering the need of written secured land tenure, but have difficulty to meet the challenge of doing the same to secure rights for farmers with loans or lease agreements. The small-scale irrigation could bring an answer for their financial needs to buy the land, but it would require mobilizing resources to invest or an easier access to supportive projects. The economic benefice from small-scale irrigation is now widely recognized, but we have to take also into account the risks of marginalization of part of the small farmers. For a more widely spread exploitation of small-scale irrigation, the mechanism of land regulation as well as the process to access the financial and technical support of projects must be revised in order to reach more small farmers. Développement de l'irrigation et évolution des régimes fonciers dans la région de Gaya (Niger) - Le secteur de l'irrigation a bénéficié d'un regain d'intérêt de la part des acteurs internationaux du développement et de l'Etat nigérien depuis le milieu des années 1990. Cet intérêt est à la hauteur du potentiel en terres irrigables (300Ό00 ha environ) du pays, largement sous-exploité alors que les besoins alimentaires sont grandissants, la population augmentant de 3.3% par an. Si le diagnostic est correct, les stratégies mises en oeuvre en matière d'irrigation posent question. Les interventions, aussi bien publiques qu'internationales, reposent sur un modèle entrepreneurial qui parachève une longue trajectoire historique. Initiée par l'Etat colonial, poursuivie par l'Etat post-colonial et transformé par les politiques néolibérales des années 1980, elle se caractérise par un hiatus constant entre logiques étatiques et logiques paysannes. En matière de petite irrigation privée (surfaces < 1-2 ha, technologies à faible coût), ce modèle présuppose une mobilisation de ressources (économiques, sociales, éducationnelles et foncières) inégalement réparties au sein de la population rurale. Cette recherche s'est intéressée à expliciter les liens qui existent entre le développement de la petite irrigation privée et l'évolution des régimes fonciers. Les trois questionnements qui ont guidé l'analyse empirique portent sur la sécurisation foncière, les dynamiques de marchandisation de la terre et l'accès à la terre pour tous les producteurs. Le Département de Gaya dispose d'un potentiel très important en ressources hydriques, facilement mobilisables. Les productions maraîchères et fruitières ont connu un essor très important à partir des années 1980. Initialement pratiquées par les cultivateurs, elles ont progressivement attiré l'attention d'acteurs externes au monde rural (fonctionnaires, commerçants), du fait de leur haute valeur ajoutée. La Banque mondiale a fortement soutenu cette dynamique à travers un projet à vocation entrepreneuriale, qui s'est pourtant révélé hors de portée de la majorité des petits paysans et a principalement bénéficié à ces acteurs extra-ruraux ainsi qu'à certaines élites locales. Au plan foncier, il a en particulier exclu tous les emprunteurs des terres, qui ne sont pas à même de produire des documents écrits confirmant leurs droits sur la terre. Ce projet, et plus largement l'intérêt que les acteurs extra-ruraux portent à la petite irrigation, ont contribué à alimenter la marchandisation de la terre. Sans ancrage familial dans les terroirs villageois, ces acteurs sont obligés d'acheter la terre pour faire de l'irrigation. Leur demande vient s'inscrire dans un contexte général où la pression démographique et le morcellement successif des capitaux fonciers familiaux ont progressivement individualisé la relation entre les producteurs et la terre, au point d'affaiblir ou de faire tomber les interdits coutumiers en matière de vente. Dans les espaces disposant de faibles réserves foncières, les ventes se font principalement au détriment des acteurs qui, comme les emprunteurs, disposent de droits fonciers peu stables et sécurisés. Si le retrait de la terre est socialement encadré (terre en remplacement, possibilité d'acheter la terre qui va être vendue), il pose également des contraintes agronomiques (sols de moindre qualité) et économiques (nécessité de disposer des liquidités pour racheter la terre) qui peuvent, en dernier ratio, obligent les acteurs concernés à quitter les terroirs. Les instances du Code rural, qui ont su apporter des réponses satisfaisantes à la demande de sécurisation foncière par l'établissement de documents écrits, rencontrent aujourd'hui de grandes difficultés à en faire de même pour les droits de prêt. Dans ce contexte, l'irrigation peut apporter les sommes nécessaires à l'achat des terres. Encore faut-il que ces emprunteurs disposent des ressources financières propres pour la développer ou qu'ils puissent y avoir accès grâce à l'appui d'un projet. Si l'intérêt économique de la petite irrigation privée est indiscutable, les risques de marginalisation d'une partie de producteurs ruraux qu'elle peut produire sont bien réels. Pour en faire une activité accessible au plus grand nombre, il faut revoir les mécanismes de régulation foncière, ainsi que les montages techniques et financiers qui supportent le développement de ce secteur d'activité très prometteur.

Passive smoking in babies: The BIBE Study (Brief Intervention in babies. Effectiveness)

Background: There is evidence that exposure to passive smoking in general, and in babies in particular, is an important cause of morbimortality. Passive smoking is related to an increased risk of pediatric diseases such as sudden death syndrome, acute respiratory diseases, worsening of asthma, acute-chronic middle ear disease and slowing of lung growth.The objective of this article is to describe the BIBE study protocol. The BIBE study aims to determine the effectiveness of a brief intervention within the context of Primary Care, directed to mothers and fathers that smoke, in order to reduce the exposure of babies to passive smoking (ETS).Methods/DesignCluster randomized field trial (control and intervention group), multicentric and open. Subject: Fathers and/or mothers who are smokers and their babies (under 18 months) that attend pediatric services in Primary Care in Catalonia.The measurements will be taken at three points in time, in each of the fathers and/or mothers who respond to a questionnaire regarding their baby's clinical background and characteristics of the baby's exposure, together with variables related to the parents' tobacco consumption. A hair sample of the baby will be taken at the beginning of the study and at six months after the initial visit (biological determination of nicotine). The intervention group will apply a brief intervention in passive smoking after specific training and the control group will apply the habitual care.Discussion: Exposure to ETS is an avoidable factor related to infant morbimortality. Interventions to reduce exposure to ETS in babies are potentially beneficial for their health. The BIBE study evaluates an intervention to reduce exposure to ETS that takes advantage of pediatric visits. Interventions in the form of advice, conducted by pediatric professionals, are an excellent opportunity for prevention and protection of infants against the harmful effects of ETS.

The role of soil in vegetated gravelly river braid plains: more than just a passive response?

This paper reviews the role of alluvial soils in vegetated gravelly river braid plains. When considering decadal time scales of river evolution, we argue that it becomes vital to consider soil development as an emergent property of the developing ecosystem. Soil processes have been relatively overlooked in accounts of the interactions between braided river processes and vegetation, although soils have been observed on vegetated fluvial landforms. We hypothesise that soil development plays a major role in the transition (speed and pathway) from a fresh sediment deposit to a vegetated soil-covered landform. Disturbance (erosion and/or deposition), vertical sediment structure (process history), vegetation succession, biological activity and water table fluctuation are seen as the main controls on early alluvial soil evolution. Erosion and deposition processes may not only act as soil disturbing agents, but also as suppliers of ecosystem resources, because of their role in delivering and changing access (e.g. through avulsion) to fluxes of water, fine sediments and organic matter. In turn, the associated initial ecosystem may influence further fluvial landform development, such as through the trapping of fine-grained sediments (e.g. sand) by the engineering action of vegetation and the deposit stabilisation by the developing above and belowground biomass. This may create a strong feedback between geomorphological processes, vegetation succession and soil evolution which we summarise in a conceptual model. We illustrate this model by an example from the Allondon River (CH) and identify the research questions that follow.

Effect of irrigation water on the incidence of Salmonella spp. on lettuces produced by urban agriculture and sold on the markets in Dakar, Senegal

The aim of our survey was to assess the effect of irrigation water of the microbiological quality on the production chain of lettuce in the Dakar area. Microbiological analysis showed that 35% of irrigation water was contaminated by Salmonella spp. between the two water-types used for irrigation (groundwater and wastewater), no significant difference (p>0.05) in their degree of contamination was found. The incidence of different types of irrigation water on the contamination rate of lettuces from the farm (Pikine and Patte d'Oie) was not different either (p>0.05). However, the contamination rate of lettuce from markets of Dalifort and Grand-Yoff that were supplied by the area of Patte d'Oie was greater than those of Sham and Zinc supplied by Pikine (p<0.05). Comparison of serotypes of Salmonella isolated from irrigation water and lettuce showed that irrigation water may affect the microbiological quality of lettuce. Manures, frequently used as organic amendment in cultivating lettuce are another potential source of contamination. These results showed that lettuce may constitute effective vectors for the transmission of pathogens to consumers. Extensive treatment of the used wastewater and/or composting of manure could considerably reduce these risks.

Low density polyethylene (LDPE) passive samplers for the investigation of polychlorinated biphenyl (PCB) point sources in rivers

This study aims to provide a passive sampling approach which can be routinely used to investigate polychlorinated biphenyl (PCB) sources in rivers. The approach consists of deploying low density polyethylene (LDPE) strips downstream and upstream of potential PCB sources as well as in their water discharges. Concentrations of indicator PCBs (iPCBs) absorbed in samplers (Cs) from upstream and downstream sites are compared with each other to reveal increases of PCB levels. Cs measured in water discharges are used to determine if released amounts of PCBs are compatible with increases revealed in the river. As water velocity can greatly vary along a river stretch and influences the uptake at each site in a different way, differences in velocity have to be taken into account to correctly interpret Cs. LDPE strips were exposed to velocities between 1.6 and 37 cm s−1 using a channel system built in the field. Relationships between velocity and Cs were established for each iPCB to determine the expected change in Cs due to velocity variations. For PCBs 28 and 52, this change does not exceed a factor 2 for velocity variations in the range from 1.6 to 100 cm s−1 (extrapolated data above 37 cm s−1). For PCBs 101, 138, 153 and 180, this change only exceeds a factor 2 in the case of large velocity variations. The approach was applied in the Swiss river Venoge to first conduct a primary investigation of potential PCB sources and then conduct thorough investigations of two suspected sources.