Optimal provision of infrastructure using public-private partnership contracts

This paper deals with the optimal provision of infrastructure by means of public-private partnership contracts.In the economic literature infrastructure is characterized as a large, indivisible and non-rival capital good that produces services for its users.Users can be both consumers and producers. Consumers may derive utility from infrastructure, either indirectly, because it facilitates the use of some particular private good, or directly, because it is available for this facility.Examples are roads that facilitate the use of private cars, or computer systems facilitating the use of personal computers. Producers may use infrastructure as one of their production factors.The non-rivalness or nonexcludability of the infrastructure and the large costs to produce and maintain the infrastructure causes it to be a public good.On the other hand, infrastructure also possesses characteristics of a private commodity because it facilitates of the use of a complementary private commodity.Modern information-technological developments open new possibilities to eveal the need of individual users for a specific public infrastructure, by monitoring the private use they make of it.Consequently, a large part of the public financing of infrastructure can be privatised.That forms the base for public private partnerships to establish and maintain infrastructure.In this paper we discuss the design of an operational system to finance the costs of infrastructure.It will be shown that the system basically can result in an economically efficient level of infrastructure.The basic idea is that use of infrastructure is constrained by the availability of the infrastructure being provided.Therefore users who are hampered by too small a provision of the infrastructure are willing to pay for the use of infrastructure.

The frequency of bowel and bladder problems in multiple sclerosis and its relation to fatigue: A single centre experience

Background Bowel and bladder problems affect more than 50% of people with Multiple Sclerosis (MS). These problems have a large impact on quality of life and place a significant burden on health systems. Objectives This study aimed to ascertain the frequency of bladder and bowel problems in a select Australian MS cohort and to investigate the relationships between level of disability, bladder and bowel problems, and fatigue. Methods Questionnaires on the nature and severity of MS symptoms were distributed to clients attending an Australian MS centre. Log-binomial regression and multiple linear regression models were used to investigate relationships between disability, fatigue, and bladder and bowel problems. Results and conclusions Of 167 questionnaires distributed, 136 were completed. Bladder problems were reported by 87 (74.4%) respondents, whilst 66 (48.9%) experienced functional constipation and 43 (31.9%) faecal incontinence. This frequency in our select Australian MS population is similar to that reported globally. There was a significant correlation between level of disability and: bladder problems (p = 0.015), faecal incontinence (p = 0.001), fatigue (p<0.001) and constipation (p = 0.016, relative risk: 1.16). Further investigation into the causal relationships between various MS symptoms may be beneficial in the development of novel therapeutic strategies for people with MS

The bounded retransmission protocol must be on time!

This paper concerns the transfer of files via a lossy communication channel. It formally specifies this file transfer service in a property-oriented way and investigates -using two different techniques -whether a given bounded retransmission protocol conforms to this service. This protocol is based on the well-known alternating bit protocol but allows for a bounded number of retransmissions of a chunk, i.e., part of a file, only. So, eventual delivery is not guaranteed and the protocol may abort the file transfer. We investigate to what extent real-time aspects are important to guarantee the protocol's correctness and use Spin and Uppaal model checking for our purpose

Stability in a network economy: The role of institutions

We consider an economy in which agents are embedded in a network of potential value-generating relationships. Agents are assumed to be able to participate in three types of economic interactions: Autarkic self-provision; bilateral interaction; and multilateral collaboration through endogenously provided platforms. We introduce two stability concepts and provide sufficient and necessary conditions on the network structure that guarantee existence, in cases of the absence of externalities, link-based externalities and crowding externalities. We show that institutional arrangements based on socioeconomic roles and leadership guarantee stability. In particular, the stability of more complex economic outcomes requires more strict and complex institutional rules to govern economic interactions. We investigate strict social hierarchies, tiered leadership structures and global market places

The effect of social context on the use of visual information

Social context modulates action kinematics. Less is known about whether social context also affects the use of task relevant visual information. We tested this hypothesis by examining whether the instruction to play table tennis competitively or cooperatively affected the kind of visual cues necessary for successful table tennis performance. In two experiments, participants played table tennis in a dark room with only the ball, net, and table visible. Visual information about both players’ actions was manipulated by means of self-glowing markers. We recorded the number of successful passes for each player individually. The results showed that participants’ performance increased when their own body was rendered visible in both the cooperative and the competitive condition. However, social context modulated the importance of different sources of visual information about the other player. In the cooperative condition, seeing the other player’s racket had the largest effects on performance increase, whereas in the competitive condition, seeing the other player’s body resulted in the largest performance increase. These results suggest that social context selectively modulates the use of visual information about others’ actions in social interactions

Altered Negative Unconscious Processing in Major Depressive Disorder: An Exploratory Neuropsychological Study

Major depressive disorder (MDD) has been characterized by abnormalities in emotional processing. However, what remains unclear is whether MDD also shows deficits in the unconscious processing of either positive or negative emotions. We conducted a psychological study in healthy and MDD subjects to investigate unconscious emotion processing and its valence-specific alterations in MDD patients.We combined a well established paradigm for unconscious visual processing, the continuous flash suppression, with positive and negative emotional valences to detect the attentional preference evoked by the invisible emotional facial expressions.Healthy subjects showed an attentional bias for negative emotions in the unconscious condition while this valence bias remained absent in MDD patients. In contrast, this attentional bias diminished in the conscious condition for both healthy subjects and MDD.Our findings demonstrate for the first time valence-specific deficits specifically in the unconscious processing of emotions in MDD; this may have major implications for subsequent neurobiological investigations as well as for clinical diagnosis and therapy