To die at home

Norsk sammendrag:Norsk sammendrag: Bakgrunn: De fleste pasienter ønsker å dø hjemme. Norge er av de land i verden hvor færrest dør i eget hjem. En av grunnene til at ønskene ikke blir oppfylt er blant annet manglende trygghet blant pårørende. Som kreftsykepleier har vi et ansvar for den helhetlige omsorgen av pårørende til den døende kreftpasienten. Hensikt: Formålet med oppgaven er å undersøke hvilke betydning fenomenet mot har i det første møte med pårørende til døende kreftpasienter for å styrke pårørende slik at pasienten kan dø hjemme. Det mellommenneskelige aspektet mellom pårørende og kreftsykepleier i det første møte er i fokus. Problemstilling: Hvordan kan kreftsykepleier i det første møte med pårørende til døende kreftpasient bidra til å styrke pårørendes mot slik at pasienten kan dø hjemme? Metode: Oppgaven er en litteraturstudie som bygger på kunnskap fra bøker og andre skriftlige kilder, søk i databaser kombinert med egne erfaringer fra praksis. Resultat: Funn viser at pårørende fant det betydningsfullt å bli sett, hørt og være deltagende. I møte med kreftsykepleier vektlegges tilstedeværelse, øyekontakt, dialog og god kommunikasjon. Nærhet og håp er viktige fundament for omsorg, og får en spesiell dimensjon i omsorgen for pårørende til døende kreftpasienter. Konklusjon: Å styrke pårørende til døende kreftpasienter slik at pasienten kan dø hjemme bør være et overordnet mål i den helhetlige omsorgen av de pårørende. Kreftsykepleier må være oppmerksom på de pårørendes ulike behov og utfordringer i det første møte. Slik vil kreftsykepleier kunne bidra til at pårørende styrkes i sitt mot slik at pasienten kan dø hjemme.English abstract: Background: Most of the people who are dying, wish to die in their own home. Very few people in Norway get their wish about dying at home fulfilled. One of the reasons that their wishes are not fulfilled, is insecurity among relatives. As oncology nurses, we have a responsibility for general care for the relatives. Purpose: To study what affect the phenomenon courage has in the first meeting with relatives of a dying cancer patient, and how courage can strengthen relatives, so that the patient can die at home. The interpersonal aspect between relatives and the oncology nurse in the first meeting is in focus. Problem: How can an oncology nurse contribute to strengthen relatives already in the first meeting, in such way so that the patient can die at home? Method: This study is a literature study that builds on knowledge from books and other written sources, search in data bases combined with experiences from practice. Result: Findings show that relatives find it meaningful to be seen, heard and to participate. Presence, eye contact, dialogue and good communication are important in an appointment with an oncology nurse. To have hope and to be close are foundations that are important in health care. These two foundations have a special dimension in the care of dying cancer patients. Conclusion: To strengthen relatives of dying cancer patients so that the patient can die at home should be a superior goal in the general care of relatives. Oncology nurses have to consider the needs and challenges of relatives already in the first meeting. That way, oncology nurses can contribute to strengthen the relative’s courage, so that the patient can die at home

Grasses and the resource availability hypothesis: the importance of silica-based defences

The resource availability hypothesis (RAH) predicts that allocation of resources to anti-herbivore defences differs between species according to their growth rate. We tested this hypothesis by assessing the growth and defence investment strategies of 18 grass species and comparing them against vole feeding preferences. In addition, we assessed the effectiveness of silica, the primary defence in many grasses, in influencing vole feeding behaviour. Across species, we found that there was a strong negative relationship between the overall investment in defence and growth rate, thus supporting predictions of the RAH. However, no such relationship was found when assessing the various individual anti-herbivore defences, suggesting that different grass species show significant variation in their relative investment in strategies such as phenolic concentration, silica concentration and leaf toughness. Silica was the most influential defensive factor in determining vole feeding preference. Experimentally induced increases in leaf silica concentration deterred vole feeding in three of the five species tested, and altered feeding preference ranks between species. The strong positive relationship between silica concentration and leaf abrasiveness, when assessed both within and between species, suggests that increased abrasiveness is the mechanism by which silica deters feeding. Although grasses are often considered to be tolerant of herbivore damage rather then defended against it, they do follow predictions of defence allocation strategy based on their growth rates, and this affects the feeding behaviour of generalist grass-feeding herbivores

Experimental demonstration of the antiherbivore effects of silica in grasses: impacts on foliage digestibility and vole growth rates

The impact of plant-based factors on the population dynamics of mammalian herbivores has been the subject of much debate in ecology, but the role of antiherbivore defences in grasses has received relatively little attention. Silica has been proposed as the primary defence in grasses and is thought to lead to increased abrasiveness of foliage so deterring feeding, as well as reducing foliage digestibility and herbivore performance. However, at present there is little direct experimental evidence to support these ideas. In this study, we tested the effects of manipulating silica levels on the abrasiveness of grasses and on the feeding preference and growth performance of field voles, specialist grass-feeding herbivores. Elevated silica levels did increase the abrasiveness of grasses and deterred feeding by voles. We also demonstrated, for the first time, that silica reduced the growth rates of both juvenile and mature female voles by reducing the nitrogen they could absorb from the foliage. Furthermore, we found that vole feeding leads to increased levels of silica in leaves, suggesting a dynamic feedback between grasses and their herbivores. We propose that silica induction due to vole grazing reduces vole performance and hence could contribute to cyclic dynamics in vole populations

Nephropathia epidemica and Puumala virus occurrence in relation to bank vole (Clethrionomys glareolus) dynamics and environmental factors in northern Sweden

The objectives of the thesis were to investigate the spatio-temporal patterns of nephropathia epidemica (NE) in humans and Puumala virus (PUU) occurrence in relation to bank vole (Clethrionomys glareolus) dynamics and environmental factors in a region of high incidence of NE in northern Sweden. Nephropathia epidemica is a mild form of hemorrhagic fever with renal syndrome, and in northern Sweden the most prevailing serious febrile viral infection, second to influenza. All serologically confirmed NE cases during 1991-2001 in the four northernmost counties (n = 2,468) were used to establish spatio-temporal patterns of the occurrence of the human disease. Within the study region, the bank voles show marked population fluctuations with 3-4 yr cycles and the incidence of NE has a temporal component strongly correlated to annual numbers of bank voles in autumn. People living in rural dwellings near coastal areas were abundant among notified cases and middle-aged males were over-represented. The patients were often infected in autumn when engaged in activities such as handling of fire wood, gardening or hay-handling near man-made rodent refugia or cleaning/redecorating within one. A proportion of these patients, confident about site of PUU exposure, were used to establish field sites in two separate studies. Firstly a five year study (1995-1999) at six sites spanning a bank vole population cycle, and secondly a spatially extensive study at 32 sites was conducted in autumn 1998. Densities, fluctuations and demography of vole populations differ between sites of known occurrence of NE were compared to random forest sites. Five years of repeated biannual sampling revealed that case sites harbored more bank voles than random forest sites, in particular during population peaks. For the individual bank voles, the probability of PUU infection was significantly higher in population peak year, increased with age and was higher for males than for females. In the spatially extended study, it was found that in particular environmental characteristics associated with old-growth moist forests (i.e. Alectoria spp., Picea abies, fallen wood and Vaccinium myrtillus) were associated with high bank vole numbers and numbers of PUU infected bank voles. This implies that success in circulation and persistence of PUU within local bank vole populations is strongly influenced by the local environments. In future modeling of PUU transmission, influence of bank vole demography and environmental factors should be useful on establishing risk assessments and identifying areas of particular risk of PUU exposure

How expensive is vole damage?

Vole species, especially Arvicola terrestris and Microtus arvalis cause significant economical damage in organic pomiculture by gnawing the root system of trees. The importance of voles as pest organisms is well known. Nevertheless, the estimation of financial loss caused by voles is difficult for German fruit growers. We conducted a survey among organic fruit growers to get data on kind and amount of annual damage. Using the available publications and official statistics we calculated economical values of organic apple trees for different types of orchard processing and tree ages. Furthermore we calculated the number of trees lost due to voles in one year

Spatial prediction of species’ distributions from occurrence-only records: combining point pattern analysis, ENFA and regression-kriging

A computational framework to map species’ distributions (realized density) using occurrence-only data and environmental predictors is presented and illustrated using a textbook example and two case studies: distribution of root vole (Microtes oeconomus) in the Netherlands, and distribution of white-tailed eagle nests (Haliaeetus albicilla) in Croatia. The framework combines strengths of point pattern analysis (kernel smoothing), Ecological Niche Factor Analysis (ENFA) and geostatistics (logistic regression-kriging), as implemented in the spatstat, adehabitat and gstat packages of the R environment for statistical computing. A procedure to generate pseudo-absences is proposed. It uses Habitat Suitability Index (HSI, derived through ENFA) and distance from observations as weight maps to allocate pseudo-absence points. This design ensures that the simulated pseudo-absences fall further away from the occurrence points in both feature and geographical spaces. The simulated pseudo-absences can then be combined with occurrence locations and used to build regression-kriging prediction models. The output of prediction are either probabilitiesy of species’ occurrence or density measures. Addition of the pseudo-absence locations has proven effective — the adjusted R-square increased from 0.71 to 0.80 for root vole (562 records), and from 0.69 to 0.83 for white-tailed eagle (135 records) respectively; pseudo-absences improve spreading of the points in feature space and ensure consistent mapping over the whole area of interest. Results of cross validation (leave-one-out method) for these two species showed that the model explains 98% of the total variability in the density values for the root vole, and 94% of the total variability for the white-tailed eagle. The framework could be further extended to Generalized multivariate Linear Geostatistical Models and spatial prediction of multiple species. A copy of the R script and step-by-step instructions to run such analysis are available via contact author’s website

Prevention of vole damage in organic pomiculture

Vole damage is one of the most difficult phytosanitary problems to solve in organic pomiculture. A survey conducted in 2002 among German fruit growers showed that 90 % of the farms suffered from this damage. The water vole (A. terrestris) revealed to be the main pest in 80 % of the orchards. 61 % of the farmers announced a high interest in the development of new preventive and control methods. To stop immigration of voles into orchards a mechanical barrier system was developed and tested at two study sites in Baden-Wuerttemberg and Rhineland-Palatinate. At each location barrier systems with wire mesh (mesh size 10 mm) and polyolefine-foil were installed arround two 0.7 ha study plots. Two unprotected plots were used as a control. The barriers were anchored 20 cm deep into the soil. 30 cm of the material protruded over the surface. Automatic gates were installed for the entrance of vehicles. 4 persons needed approximately one day to install a barrier around a plot with the size of 1 ha. Not only was the wire mesh cheaper than the foil, it was permeable for wind, water and small beneficial organisms. After installing the barrier systems, voles were removed from all plots. Snap trap boxes were ranged along the outside of the barriers to catch migrating voles. A total of 33 water voles and 1263 common voles (M. arvalis) were captured on both study sites from October 2002 to November 2003. During the study period a total of 5 water voles immigrated into the first control plot and 6 settled into the other plot. Four water voles entered two of the barrier protected plots by using fresh mole galleries. The other protected plots stayed free from water voles. Simultaneous to the field studies, trials in two enclosures were carried out in Muenster. The barriers kept all water voles outside the protected plots. The results showed a high efficacy of the developed barrier system

Experimental evidence that livestock grazing intensity affects cyclic vole population regulation processes

Peer reviewedPublisher PD

Vole trapping fences - a new approach to migration barriers

To control problematic vole species in organic orchards farmers can choose between different measures. Some methods like gassing, trapping and even the support of natural vole antagonists target to reduce vole population by killing individuals. Other methods like protective guards or migration barriers exclude voles from single trees or whole orchards. Recent combinations of the two approaches worked well but had some drawbacks in practice. Nevertheless, efficiency of migration barriers can be improved by attracted natural predators. Here we present first practical experiences and field observations of a vole-trapping-fence prototype. The new construction consists of prefabricated recyclable polypropylene pieces which are mounted to modules and assembled to fences of any length. It has a H-shaped profile with the horizontal line at ground level. The two „legs“ are pushed into the ground and the two „arms“ building a double wall fence above ground. Through one-way doors voles can enter the space between the walls they are trapped in. In contrast to wire mesh fences it allows the seasonal use in annual cultures due to its fast mounting and dismantling features. For the long term protection of orchards, however, an additional wire mesh to prevent deep tunnelling is still recommended. The above ground construction has shown some additional advantages as maintenance is easier with a decreased risk of penetration by mowing devices. Most important the new construction improved the accessibility by predators as not only terrestrial but also avian predators were attracted and were able to take the captured voles

Reliability assessment of null allele detection: inconsistencies between and within different methods

Microsatellite loci are widely used in population genetic studies, but the presence of null alleles may lead to biased results. Here we assessed five methods that indirectly detect null alleles, and found large inconsistencies among them. Our analysis was based on 20 microsatellite loci genotyped in a natural population of Microtus oeconomus sampled during 8 years, together with 1200 simulated populations without null alleles, but experiencing bottlenecks of varying duration and intensity, and 120 simulated populations with known null alleles. In the natural population, 29% of positive results were consistent between the methods in pairwise comparisons, and in the simulated dataset this proportion was 14%. The positive results were also inconsistent between different years in the natural population. In the null-allele-free simulated dataset, the number of false positives increased with increased bottleneck intensity and duration. We also found a low concordance in null allele detection between the original simulated populations and their 20% random subsets. In the populations simulated to include null alleles, between 22% and 42% of true null alleles remained undetected, which highlighted that detection errors are not restricted to false positives. None of the evaluated methods clearly outperformed the others when both false positive and false negative rates were considered. Accepting only the positive results consistent between at least two methods should considerably reduce the false positive rate, but this approach may increase the false negative rate. Our study demonstrates the need for novel null allele detection methods that could be reliably applied to natural population