Voluntary Cooperation in the Provision of a Semi-public Good. Community-based Soil and Water Conservation in Semi-arid India.

This dissertation analyses the question whether households in India’s semi-arid tropics can be expected to voluntarily maintain semi-public investments in soil and water conservation. Increasingly, public investment programs decentralise project planning, implementation and management to local communities, whereas it is unclear whether local communities can be expected to effectively manage these investments in the long run. The analysis in this dissertation suggests that to maintain a socially efficient level of soil and water conservation investments it is important that a strategic coalition of cooperative households exists. Also, the external environment plays an important role. Emerging labour markets, market access and resource scarcity all help determine whether individual households have an incentive to cooperate in semi-public good provision or not. Using experimental data on village trust levels, the analysis suggests that targeting investments at homogeneous communities might help improve project effectiveness, since communities with higher trust levels are more likely to maintain public investments than communities where trust is low. Finally, the analysis suggests that decentralising decision-making can also have a negative effect. When water is scarce, upstream investments in soil and water conservation might negatively affect farmers downstream. Hence, for community-based interventions to be welfare enhancing it is crucial that the potential externalities of decentralised decision-making are sufficiently addressed.

Rate of inter-herd transmission of classical swine fever virus by different types of contact during the 1997-8 epidemic in The Netherlands

In this study we quanti®ed the rate at which classical swine fever had been transmitted by several different types of inter-herd contact during the 1997±8 epidemic in The Netherlands. During that epidemic 428 CSFV-infected pig herds were detected, 403 of which were include in this study. The estimated rates of transmission were 0±065 per shipment of live pigs, 0±011 per contact by a pig transportation lorry, 0±0068 per person contact, 0±0007 per dose of semen, 0±0065 per contact with a potentially contaminated pig assembly point, 0±027 per week per infected herd within a radius of 500 metres and 0±0078 per week per infected herd at a distance between 500 and 1000 metres. These transmission rates can be used to optimize the strategy to stop future epidemics of CSF in The Netherlands. In addition, the analysis demonstrated in this paper, can be used to quantify CSFV transmission rates from other epidemics

The impact of specific language impairment on working memory in children with ADHD combined type

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldThe objective of this study was to examine the impact of comorbid specific language impairment (SLI) on verbal and spatial working memory in children with DSM-IV combined subtype Attention Deficit Hyperactivity Disorder (ADHD-C). Participants were a clinical sample of 812- to 1212-year-old children diagnosed with ADHD-C. A group of ADHD-C with SLI was compared to a group of ADHD-C without SLI, and a group of normal children, matched on age and nonverbal intelligence. The results show that ADHD-C children with SLI scored significantly lower than those without SLI and normal children, on verbal working memory measures only. Both ADHD groups performed normally on spatial working memory measures. It is concluded that working memory deficits are not a specific characteristic of ADHD but are associated with language impairments. The importance of screening for language disorders in studies of neuropsychological functioning in children with ADHD is emphasized

The Acute versus Chronic Pain Questionnaire (ACPQ) and actual pain experience in older people

The Acute versus Chronic Pain Questionnaire (ACPQ) was applied to older people. Two groups emerged from an analysis of which an item of each pair (an acute and a chronic affective item) was considered to cause the most suffering. One group of subjects comprised those who expected to suffer more from one or more acute pain items (high-ACPQ group, n = 35). A second group emerged for whom none of the acute items was considered to be a burden (low-ACPQ group, n = 33). It was hypothesized that, compared to the low-ACPQ group, the subjects with high-ACPQ scores selected acute ACPQ-items due to a decline in the experience of chronic affective pain. This hypothesis predicted lower scores on the chronic ACPQ-items and lower scores on scales evaluating the subjects' own chronic affective pain. The results showed that, irrespective of the group, the chronic ACPQ-items were considered to produce the most burdens. However, compared with the low-ACPQ group, the high-ACPQ group reported experiencing significantly more pain from the acute ACPQ-items. Moreover, the latter group indicated suffering less pain from their own chronic pain conditions. The present findings suggest that the selection of one or more acute items of the ACPQ (high-ACPQ group) may point to an alteration in subjects' actual pain experience

Patches in a side-by-side configuration: a description of the flow and deposition fields

In the last few decades, a lot of research attention has been paid to flow-vegetation interactions. Starting with the description of the flow field around uniform macrophyte stands, research has evolved more recently to the description of flow fields around individual, distinct patches. However, in the field, vegetation patches almost never occur in isolation. As such, patches will influence each other during their development and interacting, complex flow fields can be expected. In this study, two emergent patches of the same diameter (D = 22 cm) and a solid volume fraction of 10% were placed in a side-by-side configuration in a lab flume. The patches were built as an array of wooden cylinders, and the distance between the patches (gap width Delta) was varied between Delta = 0 and 14 cm. Flow measurements were performed by a 3D Vectrino Velocimeter (Nortek AS) at mid-depth of the flow. Deposition experiments of suspended solids were performed for selected gap widths. Directly behind each patch, the wake evolved in a manner identical to that of a single, isolated patch. On the centerline between the patches, the maximum velocity U-max was found to be independent of the gap width Delta. However, the length over which this maximum velocity persists, the potential core L-j, increased linearly as the gap width increased. After the merging of the wakes, the centerline velocity reaches a minimum value U-min. The minimum centerline velocity decreased in magnitude as the gap width decreased. The velocity pattern within the wake is reflected in the deposition patterns. An erosion zone occurs on the centerline between the patches, where the velocity is elevated. Deposition occurs in the low velocity zones directly behind each patch and also downstream of the patches, along the centerline between the patches at the point of local velocity minimum. This downstream deposition zone, a result of the interaction of neighbouring patch wakes, may facilitate the establishment of new vegetation, which may eventually inhibit flow between the upstream patches and facilitate patch merger

Analysing Group Contract Design Using a Lab and a Lab-in-the-Field Threshold Public Good Experiment

This paper presents the results of a threshold public goods game experiment with heterogeneous players. The experiment is designed in close collaboration with the Dutch association of agri-environmental farmer collectives. Subjects are recruited at a university (“the lab”) and a farm management training centre (“lab-in-the-field”). The treatments have two different distribution rules which are varied in a within-subjects manner. After subjects have experienced both, they can vote for one of the two rules: either a differentiated bonus that results in equal payoff for all, or an undifferentiated, equal share of the group bonus. In a between-subjects manner, subjects can vote for a (minimum or average) threshold or are faced with an exogenous threshold. The results indicate that exogenous thresholds perform better, possibly because the focal point they provide facilitates coordination. With regard to the two distribution rules, the results are mixed: average contributions and payoffs are higher in the lab under the ‘equal-payoff’ rule, but there is no significant difference between the two in the lab-in-the-field, possibly because contributions in the lab-in-the-field are much less efficient. Overall, our results suggest that environmental payment schemes should not only consider farmer heterogeneity in the design of group contracts, but pay explicit attention to coordination problems as well

Field trial for assessment of avian influenza vaccination effectiveness in Indonesia

The aim of this field study was to determine the efficacy of vaccination against highly pathogenic avian influenza (HPAI) virus strain H5N1 in Indonesia. A limited, prototype clinical trial was performed using a standardised treatment group, in which poultry flocks were vaccinated at least twice with a selected H5N1 vaccine, and a control group comprising flocks treated with nonstandardised procedures chosen by the farmer. Each group consisted of six flocks comprising either layers or native chickens. Haemagglutination inhibition (HI) antibody levels were determined by regular serum sampling, and outbreak surveillance relied on non-Al-vaccinated sentinel birds. After three vaccinations high antibody titres were produced in the treatment group, and the percentage of layers with an HI titre > 40 was approximately 90%. Although no conclusions can be drawn regarding reduction of virus transmission, this study demonstrated that 11 farms remained free from Al during the observation period, and that a surveillance programme based on differentiating infected from vaccinated animals (DIVA) can be implemented

Values Connecting Societies and Water Systems

__Introduction__ Water systems such as rivers and lakes have many important values for ecosystems and human societies. Both economical, social-ecological, cultural and political values are met by the water systems, connecting different activities in human society and ecosystems. Water systems with low water quality serve different values than healthy water systems and have huge impact on the society. For example, for drinking water, biodiversity or recreational open space, a healthy water system is crucial. The values of the water systems are interlinked. The interlinking and overlapping values of the water systems at the spatial and temporal scales have determined a connective capacity in the water governance, be it the coordination between the values or the competition between the values and its linked governance approach. The challenge is values of water systems change with the change in the societal development and consequently influence the water governance approach. A reverse process is also evident. Unfortunately, today water systems in many cities have slowly reduced in their total value for society. The revival of the water systems such as river and lakes is thus seem to be urgent in order to enhance the values generated by these systems for the society