1,020 research outputs found

    The logsum as an evaluation measure - review of the literature and new results

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    Transport infrastructure projects in The Netherlands are appraised ex ante by using cost-benefit analysis (CBA) procedures following the so-called ‘OEI-guidelines’. The project benefits for travellers are incorporated in the form of changes in demand (e.g. from the Dutch national model system, LMS, or the regional models, NRM) and changes in the generalised travel costs (using values of time from Stated Preference studies to monetise travel time savings), and applying the rule of half. While a number of short-term improvements to the current procedures have been improved, it is also interesting to consider a more radical approach using explicit measures of consumer surplus, obtained by integrating the demand models directly. These measures are called logsums, from their functional form. The advantages that the logsums would give to the appraisal procedure would be that logsums can incorporate a degree of heterogeneity in the population, while also being theoretically more correct and in many cases easier to calculate. In this context, the Transport Research Centre (AVV) of the Dutch Ministry of Transport, Public Works and Water Management has commissioned RAND Europe to undertake a study comparing the conventional approach to the use of the logsum change as a measure of the change in consumer surplus that would result from a transport infrastructure project. The paper is based on the work conducted in the study. The paper opens with a review of the literature on the use of logsums as a measure of consumer surplus change in project appraisal and evaluation. It then goes on to describe a case study with the Dutch National Model System (LMS) for transport in which three methods are compared for a specific project (a high speed magnetic hover train that would connect the four main cities in the Randstad: Amsterdam, The Hague, Rotterdam and Utrecht): a.the ‘classical’ CBA approach as described above, b.the improved ‘classical’ CBA approach (introducing a number of short-term improvements) and c.the logsum approach (as a long term improvement). The direct effects of a particular policy on the travellers can be measured as the change in consumer surplus that results from that policy (there can also be indirect and external effects that may not be covered in the consumer surplus change). The consumer surplus associated with a set of alternatives is, under the logit assumptions, relatively easy to calculate. By definition, a person’s consumer surplus is the utility, in money terms, that a person receives in the choice situation. If the unobserved component of utility is independently and identically distributed extreme value and utility is linear in income, then the expected utility becomes the log of the denominator of a logit choice probability, divided by the marginal utility of income, plus arbitrary constants. This if often called the ‘logsum’. Total consumer surplus in the population can be calculated as a weighted sum of logsums over a sample of decision-makers, with the weights reflecting the number of people in the population who face the same representative utilities as the sampled person. The change in consumer surplus is calculated as the difference between the logsum under the conditions before the change and after the change (e.g. introduction of a policy). The arbitrary constants drop out. However, to calculate this change in consumer surplus, the researcher must know the marginal utility of income. Usually a price or cost variable enters the representative utility and, in case that happens in a consistent linear additive fashion, the negative of its coefficient is the marginal utility of income by definition. If the marginal utility of income is not constant with respect to income, as is the case in the LMS and NRM, a far more complex formula is needed, or an indirect approach has to be taken. This paper will review the theoretical literature on the use of the logsum as an evaluation measure, including both the original papers on this from the seventies and the work on the income effect in the nineties. Also recent application studies that used the logsum for evaluation purposes will be reviewed. Finally outcomes of runs with the LMS will be reported for the three different approaches (including the logsum approach) mentioned above for evaluating direct effect of transport policies and projects. Different methods for monetising the logsum change will be compared.

    Pronunciation acquisition patterns of learners with different starting levels

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    This study described the results of an investigation into the effect of an intensive 12-week pronunciation course in British English which 30 Dutch female 1st-year university students of English took. They read out the same text before and after the course. Each student’s ‘before’ and ‘after’ tests were recorded. Before analysis of their results, students were split up into three groups on the basis of their general starting level: high, intermediate and low. The analysis involved a before- and after comparison of the pronunciation of eleven different phonemes: /æ, ɒ, ɔː, ʌ, ʊ, d, θ/, medial /t/, coda /r/, and syllable-final /d, v/. The analysis was done by means of both auditory and acoustic analysis. Four degrees of success (or lack thereof) were defined. The results show that the consonants required the least effort, as they were already relatively acceptable before the course started. This was true of students in general, regardless of initial starting level. The three levels of students are most distinguishable on the basis of the development of the consonants during the course. The weaker students’ consonants in particular benefitted from the course. The research revealed that initial level can be used to predict the trajectory of improvement. A general conclusion is that teachers may recognise types of students before the course starts and subject them to different types of teaching

    Cross-border Car Traffic in Dutch Mobility Models

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    Cross-border travel generates a substantial amount of mobility near the borders, but is not a large percentage of total Dutch mobility. However in the border regions of the country, these flows are important. For the Dutch national transport model LMS, O-D matrices are required that include cross-border car travel. This is a challenging task, due to scarcity of data. First, a production model (by travel purpose) is used to calculate the total production of car journeys. Next, these journeys are distributed over domestic and foreign destinations using a simplified destination choice model. From the resulting matrix, domestic journeys are removed and only the border crossing journeys are kept. Domestic journeys are then replaced by the results of the existing much more detailed mode-and destination choice models. The new models are estimated on the Dutch national mobility survey (MON) and are of reasonable quality. The predicted numbers of border crossing journeys to Belgium and Germany are lower than the numbers from traffic counts, and therefore an additional calibration to count data totals is carried out. The results indicate that for commuting the resistance to cross the border is equivalent to 35 (Belgium) or 46 (Germany) minutes extra travel time. Also for all other travel purposes in the model, it is found that the border resistance for journeys to Belgium is smaller than that for journeys to Germany, which can be explained by the additional factor of language difference. The smallest border resistance for both countries is found for shopping journeys

    The adaptation of Dutch energy policy to emerging area-based energy practices

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    This paper sheds a light on how local conditions affect renewable energy innovation. As empirical case, we study an energy transition policy regulation in the Netherlands: the zip code-rose regulation (PCR) intended for community energy initiatives. Firstly, we analyse the capacity of the PCR to facilitate the accommodation of renewable energy projects by community energy initiatives. Secondly, we analyse how emerging area-based energy practices are feeding back into the energy policy system. Based on empirical evidence from a desk study and interviews with community energy initiatives and key governance actors we find that the policy does provide a modest incentive for initiatives to develop renewable energy projects under local conditions. Nevertheless, the policy falls short of allowing initiatives to openly seek for locally desired solutions and hence, to increase opportunities at a local level to develop projects based on local conditions. However, current difficulties with the policy are being considered at a national level urging for adaptation of Dutch energy policies

    The moderating effect of the COVID-19 pandemic on the mental wellbeing of health care workers on sustainable employability:A scoping review

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    Sustainable employability (SE) amongst healthcare workers (HCW) is an important asset for healthcare institutions. However, SE is under strain due to high work pressure, a shortage of employees, and absenteeism amongst employees based on mental problems. These developments had already started before the COVID-19 pandemic. The aim of this review is to explore whether there is a moderating effect of the COVID-19 pandemic on the mental wellbeing of HCW in the context of SE. A double blinded systematic review was conducted for this article in accordance with preferred reporting items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies were subjected to quality evaluation and narrative synthesis. The analysis of the selected literature led to the understanding that mental problems amongst HCW were already abundantly present before the COVID-19 pandemic. Mental health problems have increased in prevalence, severity, and variation. In general, a negative relation between (mental) health and SE exists. Our findings show that mental health problems have heavily impacted the SE of HCW: absenteeism has increased and perspective on work has changed. It is time to prioritize the mental health of HCW to prevent acute care capacity from declining even further and ending up in a vicious circle

    Interruption of visually perceived forward motion in depth evokes a cortical activation shift from spatial to intentional motor regions

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    Forward locomotion generates a radially expanding flow of visual motion which supports goal-directed walking. In stationary mode, wide-field visual presentation of optic flow stimuli evokes the illusion of forward self-motion. These effects illustrate an intimate relation between visual and motor processing. In the present fMRI study, we applied optic flow to identify distinct interfaces between circuitries implicated in vision and movement. The dorsal premotor cortex (PMd) was expected to contribute to wide-field forward motion flow (FFw), reflecting a pathway for externally triggered motor control. Medial prefrontal activation was expected to follow interrupted optic flow urging internally generated action. Data of 15 healthy subjects were analyzed with Statistical Parametric Mapping and confirmed this hypothesis. Right PMd activation was seen in FFw, together with activations of posterior parietal cortex, ventral V5, and the right fusiform gyms. Conjunction analysis of the transition from wide to narrow forward flow and reversed wide-field flow revealed selective dorsal medial prefrontal activation. These findings point at equivalent visuomotor transformations in locomotion and goal-directed hand movement, in which parietal-premotor circuitry is crucially implicated. Possible implications of an activation shift from spatial to intentional motor regions for understanding freezing of gait in Parkinson's disease are discussed: impaired medial prefrontal function in Parkinson's disease may reflect an insufficient internal motor drive when visual support from optic flow is reduced at the entrance of a narrow corridor. (C) 2010 Elsevier B.V. All rights reserved

    Transcallosal connection patterns of opposite dorsal premotor regions support a lateralized specialization for action and perception

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    Lateralization of higher brain functions requires that a dominant hemisphere collects relevant information from both sides. The right dorsal premotor cortex (PMd), particularly implicated in visuomotor transformations, was hypothesized to be optimally located to converge visuospatial information from both hemispheres for goal-directed movement. This was assessed by probabilistic tractography and a novel analysis enabling group comparisons of whole-brain connectivity distributions of the left and right PMd in standard space (16 human subjects). The resulting dominance of contralateral PMd connections was characterized by right PMd connections with left visual and parietal areas, indeed supporting a dominant role in visuomotor transformations, while the left PMd showed dominant contralateral connections with the frontal lobe. Ipsilateral right PMd connections were also stronger with posterior parietal regions, relative to the left PMd connections, while ipsilateral connections of the left PMd were stronger with, particularly, the anterior cingulate, the ventral premotor and anterior parietal cortex. The pattern of dominant right PMd connections thus points to a specific role in guiding perceptual information into the motor system, while the left PMd connections are consistent with action dominance based on a lead in motor intention and fine precision skills

    Handedness correlates with the dominant parkinson side:A systematic review and meta-analysis

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    Parkinson's disease (PD) characteristically presents with asymmetrical symptoms, contralateral to the side of the most extensive cerebral affection. This intriguing asymmetry, even included in the definition for diagnosing PD, however, is still part of a mystery. The relation with handedness as a common indicator of cerebral asymmetry might provide a clue in the search for causal factors of asymmetrical symptom onset in PD. This possible relationship, however, is still under debate. The objective of this study was to establish whether a relation between handedness and dominant PD side exists. We searched for cross-sectional or cohort studies that registered handedness and onset side in PD patients in PubMed, EMBASE, and Web of Science from their first record until 14 February 2011. Data about handedness and dominant PD side was extracted. Authors who registered both but not described their relation were contacted for further information. Odds ratios (ORs) were analyzed with a fixed effect Mantel-Haenszel model. Heterogeneity and indications of publication bias were limited. Our electronic search identified 10 studies involving 4405 asymmetric PD patients. Of the right-handed patients, 2413 (59.5%) had right-dominant and 1644 (40.5%) had left-dominant PD symptoms. For the left-handed patients this relation was reversed, with 142 (40.8%) right-dominant and 206 (59.2%) left-dominant PD symptoms. Overall OR was 2.13 (95% confidence interval [CI], 1.712.66). Handedness and symptom dominance in PD are firmly related with each other in such a way that the PD symptoms emerge more often on the dominant hand-side. Possible causal factors are discussed. (C) 2011 Movement Disorder Societ
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