Convergence rates of the DPG method with reduced test space degree

This paper presents a duality theorem of the Aubin-Nitsche type for discontinuous Petrov Galerkin (DPG) methods. This explains the numerically observed higher convergence rates in weaker norms. Considering the specific example of the mild-weak (or primal) DPG method for the Laplace equation, two further results are obtained. First, the DPG method continues to be solvable even when the test space degree is reduced, provided it is odd. Second, a non-conforming method of analysis is developed to explain the numerically observed convergence rates for a test space of reduced degree

The impact of voluntary environmental protection instruments on company environmental performance

In the last decade there has been increasing emphasis on the use of voluntary environmental protection tools such as corporate environmental reporting (CER) and environmental management systems (EMSs). There has been relatively little research, however, on the impact of these tools on the actual environmental performance of companies. This paper presents the findings of a survey of 40 companies operating in Western Australia to determine the extent to which the implementation of two voluntary instruments has influenced company environmental performance. The research considered four questions: To what extent have CER and EMSs influenced the environmental performance of companies operating in Western Australia? What are the characteristics of these influences? How does the influence of EMSs on environmental performance compare to that of CER? Have other external factors concurrently influenced environmental performance? In general, most respondents indicated that EMSs had influenced environmental management practices to some extent. On the other hand, CER was seen more as a public relations exercise and had less impact on company practices compared with EMSs. Other factors that influenced environmental performance included pressure from clients, senior management, the public and regulators; corporate culture; and cost savings

Age effects in identifying and localising dichotic stimuli: a corpus callosum deficit?

In the present study, dichotic listening performance of 31 older adults was compared with performance of 25 younger adults under free and focussed attention conditions. In addition to an age-related general decrease in performance, we observed in the focussed attention condition increased asymmetry in the elderly group: the decrease of recall performance was stronger for the left ear (LE) than for the right ear (RE), while the increase of localisation errors was greater for the RE than for the LE. Identifying and localising digits appear to be different processes mediated predominantly by the left and right hemisphere, respectively. Since age-related reduced performance is strongest for the ear ipsilateral to the hemisphere dominant to that particular function, these findings may be ascribed to decline of corpus callosum functioning resulting in decreased interhemispheric interaction rather than to a selective decline of right hemisphere functions

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

Visual analogue scales for pain assessment in Alzheimer's disease

Background: In earlier studies, pain assessment in patients with Alzheimer’s disease (AD) was conducted by interview, for which reliability is questionable considering the decline in expressive and receptive language abilities in AD. As similar language problems occur in young children, the reliability of pain assessment in this latter population is increased by employing visual analogue scales. Objective: By employing visual analogue scales, the current study investigated whether (1) nondemented elderly persons and AD patients comprehend the purpose of the scales and (2) AD patients, compared to nondemented elderly persons, report suffering less pain intensity and pain affect. Methods: Three visual analogue scales, i.e. the Colored Analogue Scale (CAS), the Faces Pain Scale (FPS), and the Facial Affective Scale (FAS) were administered to patients in an early and midstage of AD and to nondemented elderly persons. Results: The results show that the percentage of subjects who comprehended the CAS, FAS and FPS was for the nondemented elderly persons 100, 75 and 100%, respectively, for the early AD group 100, 50 and 60%, respectively, and for the midstage AD group 80, 20 and 30%, respectively. Furthermore, elderly persons without dementia reported experiencing more intense pain and pain affect than the early and midstage AD group. Interestingly, the early and midstage AD patients did not differ in reporting pain affect. Conclusion: Visual analogue scales may improve pain assessment in those AD patients who fully comprehend the meaning of the scales. As only the minority of midstage AD patients understood the purpose of the FAS and FPS, the search for tools, particularly to assess pain affect in this population, must continue

Analysis of reinforced concrete structures with occurrence of discrete cracks at arbitrary positions

A nonlinear analysis of in-plane loaded plates is presented, which eliminates the disadvantages of the smeared crack approach. The elements used and the computational method are discussed. An example is shown in which one or more discrete cracks are dominant

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

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

Reduction of Coxiella burnetii prevalence by vaccination of goats and sheep, the Netherlands

Recently, the number of human Q fever cases in the Netherlands increased dramatically. In response to this increase, dairy goats and dairy sheep were vaccinated against Coxiella burnetii. All pregnant dairy goats and dairy sheep in herds positive for Q fever were culled. We identified the effect of vaccination on bacterial shedding by small ruminants. On the day of culling, samples of uterine fluid, vaginal mucus, and milk were obtained from 957 pregnant animals in 13 herds. Prevalence and bacterial load were reduced in vaccinated animals compared with unvaccinated animals. These effects were most pronounced in animals during their first pregnancy. Results indicate that vaccination may reduce bacterial load in the environment and human exposure to C. burnetii