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Background: Headache is common in the elderly. Cervical degenerative changes are universal with ageing and cervicogenic headache is proposed (albeit without evidence) as a frequent cause of headache in this age group. Previous research identified a pattern of cervical musculoskeletal impairment which differentiated cervicogenic headache from other frequent headaches but this study was undertaken on younger/middle aged individuals. The value of this diagnostic pattern could be questioned for an older population with concomitant age related changes in the musculoskeletal system. The first and foremost aim of this research was to determine if cervical musculoskeletal impairment was specific to headaches classifiable as cervicogenic or was more generic to headache in elders. Participants with headache were sub-grouped on the basis of the pattern of cervical musculoskeletal impairment and the relationship between this grouping and headache classification was investigated. The presence of sensory hypersensitivity and psychological distress are features of headache that can provide information on the underlying mechanisms and provide management directives for headache. There is little knowledge of whether or not these features are influenced by a factor of age. Thus the second and third aims of this research were to investigate sensory features and psychological and quality of life features in the elderly with headache. Methods: One hundred and eighteen subjects, aged 60 to 75 years with recurrent headache and 44 controls were studied. Ninety-three reported a single headache and 25, two or more headache types. All subjects completed the Neck Disability Index (NDI), Geriatric Depression Scale-short form (GDS-S) and SF-36 questionnaires. Subjects with headache also completed a headache questionnaire and the Survey of Pain Attitudes (SOPA-35). Neck function measures included range of motion, manual examination of cervical segments, cranio-cervical flexor muscle function, joint position sense, cervical muscle strength, cross-sectional area of selected cervical extensors and posture. Sensory measures included pressure pain thresholds (PPTs) and thermal pain thresholds (TPTs). PPTs were measured over the forehead, upper neck and at a remote site (tibialis anterior). TPTs were measured over the upper neck. Results: Cluster analysis, based on the three musculoskeletal variables aligned previously with cervicogenic headache, divided headache subjects into two groups; cluster 1 (n = 57), cluster 2 (n = 50). There was significantly reduced cervical extension, axial rotation, rotation in neck flexion and lateral flexion in the headache clusters than the control group, and in the frequency of symptomatic joint dysfunction (C0-1 – C7-T1) (all p < 0.05). Subjects in cluster 1 had significantly reduced range of cervical extension and axial rotation and frequency of symptomatic joint dysfunction (C1-2 and C7-T1) compared to those in cluster 2 and controls (all p < 0.05). More subjects in cluster 1 had headaches ≥ 15 days per month and histories of head/neck trauma (both p < 0.05). Most cervicogenic headaches were grouped in cluster 1, but musculoskeletal dysfunction was also found in headaches classifiable as migraine or tension-type headache. The analysis of subjects with single headaches revealed no significant differences between the headache groups (migraine, tension-type, cervicogenic and unclassifiable headaches) and controls in pressure and cold pain thresholds (all p > 0.05). Heat pain thresholds were significantly lower in the headache groups compared to controls (all p < 0.01) but there were no differences between headache types (all p > 0.05). There were no strong relationships between any headache variable and pain thresholds. Elders with headache scored lower on most SF-36 domains, higher on the GDS-S (p < 0.05) and comparably on the SOPA-35 (p > 0.05) compared to the control group. The GDS score was below the threshold value for depression. Differences in these measures were not dependent on the headache types but rather, headache frequency. Subjects with headaches ≥ 15 days/month scored lowest on SF-36 domains and highest on GDS-S questionnaire compared to those with headache < 15 days/month and controls (all p < 0.05). The mean NDI score in the subjects with headache indicated the presence of mild to moderate neck pain and disability. No strong relationships were found between well-being and headache frequency, intensity and length of headache history. The NDI score had the greatest influence on physical well-being and GDS-S score on mental well-being (p < 0.001). Conclusions: Several aspects of cervical musculoskeletal function, heat thresholds, general well being and quality of life were altered in elders with headache. Neck dysfunction was not uniquely confined to cervicogenic headache but was a generic feature of headache in the elderly. No generalized changes in pain sensitivity were present in elders with headache. Headache had a significant impact on elders’ quality of life but was not associated with depression. Neck pain was an important factor influencing function and well-being. Conservative management such as physiotherapy may be a safe and appropriate option for elders with headache, given its frequent association with cervical musculoskeletal impairment. Further research is required for a better understanding of the neck’s role in elders’ headache.

Compared to natural forests, fast-growing plantations of exotic species such as Pinus radiata are often perceived as marginal habitat or unsuitable habitat for most native species. By studying Coleoptera (beetles) in a variety of landscape elements (pasture, native forest and different aged Pinus radiata stands) in a highly modified and fragmented landscape in New Zealand I aimed to determine the value of exotic plantation forests for native biodiversity, and how these species are affected by different sized clearfell harvest areas. Pitfall trap sampling of beetles showed that plantation forest stands can provide suitable complimentary habitat to native forest for many species. Rarefied species richness of Carabidae, Scarabaeidae and Scolytinae was not significantly different between habitats, however, habitat types differed significantly in their beetle community composition. Comparing different production habitats, Pinus radiata stands had a beetle community composition most similar to native forest. However, a small minority of species, e.g., Dichrochile maura, were restricted to native forest habitat highlighting the importance of retaining indigenous ecosystems within plantations. Unlike human modified habitats, native forests did not provide suitable habitat for exotic species. Clearfell harvesting is controversial and its impact on biodiversity is a key constraint for many forest certification programs, such as that administered by the Forest Stewardship Council (FSC). Despite this, no replicated manipulative experimental studies of the impact of different sized clearfell harvest areas on biodiversity have been undertaken at scales relevant to the New Zealand forest industry. One potential model of the impact of different clearfell harvest sizes is the concept of a threshold size. A threshold scenario may occur where clearfell harvest impacts increase at a rate disproportionate to the change in clearfell size over a small range of harvest areas, but impacts remain relatively unchanged either side of the threshold zone. I sampled Coleoptera in experimentally created 0.01, 0.05, 0.5, 5.0, 50 and 500 ha clearfells within Pinus radiata plantations in the central North Island of New Zealand. The wide range of clearfell harvest sizes, including some very small areas, such as 0.01 ha was instigated in an attempt to document potential clearfell harvest size thresholds. Rarefied native beetle species richness was higher in harvest areas compared to adjacent mature plantation stands. The beetle species richness in 5 ha and 500 ha harvest areas was significantly greater species than that in small 0.01 - 0.5 ha harvest areas. Although, the high beetle diversity recorded in 500 ha clearfells should be treated with caution due to confounding spatial autocorrelation. The degree of change in beetle community composition increased with increasing clearfell harvest area. Beetle assemblages in large harvest areas were less similar to their paired adjacent mature forest than smaller harvest areas. Although, constrained multivariate ordination techniques did show a short-term change in beetle species composition between recently clearfelled harvest areas of as little as 0.05 ha and adjacent mature P. radiata stands. The colonisation by open-habitat disturbance-adapted species was a key driver of this change, some species dispersed into clearfelled stands in significant densities within days post-harvest. Overall, there were no distinct short-term trends to the change in species richness as a function of increasing harvest area that would suggest an ecological impact threshold response. If short-term outcomes of clearfell harvesting are ameliorated by successful recolonisation, the long-term spatial arrangement of different aged stands becomes more important for the maintenance of biodiversity at the landscape level than short-term consequences of harvesting. By sampling selected beetle taxa in 1, 2, 4, 8, 16 and 26 year-old stands, I found that the abundance of seven out of eight of the species selected for analysis recovered to levels similar to those in adjacent mature forest within the timeframe of a single harvest rotation. Individual species utilised different aged stands, indicating different life-history strategies. For example, open-habitat, disturbance-adapted species such as Cicindela tuberculata and Sitona discoideus were prominent in young stands, and forest species such as Pycnomerus sophorae and Paracatops phyllobius were highly abundant in older stands. These alternative life-history strategies highlight the benefits of maintaining a mixture of different aged stands to increase biodiversity at the landscape level. This thesis fills an important gap in our knowledge of biodiversity in production landscapes. I show that plantation forests have value as complimentary habitat to native forest and they make an important contribution to the maintenance of biodiversity at the landscape level. Although clearfell harvesting is a severe disturbance to the forest ecosystem, the long-term recovery of beetle populations suggests that harvesting is not the key limiting factor to the enhancement of biodiversity in the plantation forests studied. This unusual situation is possibly the result of prior land-use history, as many plantations were established on degraded pastoral land, and harvest-sensitive species are unlikely to have survived this initial land-use change. As such, the severity of the long-term impacts of clearfell harvesting on biodiversity are likely to be context specific and will vary accordingly. The importance of spatial heterogeneity of habitat elements, including different aged plantation stands and native forest remnants, needs to be investigated in more detail to determine what limits biodiversity in this plantation landscape. Key points to consider are the proximity to, and proportion of, native forest cover in the landscape and the degree of connectivity among native remnants. It is these landscape-level attributes that may determine biodiversity at a regional scale, and more emphasis should be placed on landscape scale factors and there interaction with stand specific forest management practices. For example, the spatial mosaic of harvesting areas may need to be of a finer-scale when there are fewer native remnants within the landscape.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 91-102).

Syfte: År 2010 avskaffades revisionsplikten för de minsta företagen i Sverige. Trots att det har gått fyra år sedan dess, så är Sverige ett av de länder som har de lägsta gränsvärdena för frivillig revision i Europa. År 2013 presenterade EU ett nytt direktiv gällande dessa gränsvärden. Det pågår sedan dess diskussioner kring revisionsplikten och regeringen har startat upp en utredning huruvida EU:s redovisningsdirektiv skall införas i Sverige eller inte. Syftet med denna studie är att undersöka vilka effekter en höjning av gränsvärdena för frivillig revision kan få på redovisningen. Syftet med studien är även att visa vilka fördelar och nackdelar som frivillig revision kan medföra. Metod: Studien har en induktiv ansats med en kvalitativ metod. Primärdata har samlats in via semistrukturerade intervjuer med auktoriserade revisorer, auktoriserade redovisningskonsulter samt anställda på Bolagsverket och Skatteverket. Detta empiriska material har vi sedan analyserat och återkopplat till tidigare studier för att kunna besvara vår frågeställning. Resultat &amp; slutsats: Även om det är svårt att säga vilka exakta effekter en friare revisionsplikt kan få på den svenska redovisningen, visar resultatet av vår studie att höjda gränsvärden kan leda till en försämrad redovisningskvalitet och ett ökat skattefusk. Respondenterna uttrycker ingen särskild oro över att deras arbete kommer påverkas till följd av en friare revisionsplikt, förutom att gällande lagar kommer att behöva förändras om gränsvärdena för frivillig revision höjs. Förslag till fortsatt forskning: Eftersom det i dagsläget har visat sig svårt att uppmäta tydliga effekter av frivillig revision skulle en liknande studie med fördel kunna genomföras några år efter att en höjning av gränsvärdena skett, för att få tydligare resultat. Då med ett större urval av respondenter för att få in fler synvinklar och därmed en bredare empiri. Uppsatsens bidrag: Studien har bland annat identifierat fördelar som revision innebär för företag och dess intressenter samt visat vilka effekter en friare revisionsplikt kan få på företagens redovisning. Studien kan därför vara till hjälp för företag som överväger att välja bort revision. / Aim: In the year 2010 Sweden abolished mandatory audit for the smallest companies in the country. After four years Sweden still has the lowest thresholds for voluntary audit in Europe. In the year 2013 the European Union presented a new directive concerning these thresholds. Since this new directive there has been discussions about mandatory audit and the Swedish government has started an investigation, whether the directive from the European Union shall be implemented in Sweden or not. This study aims to examine the impact increased thresholds will have on accounting. The study also aims to show the advantages and disadvantages that voluntary audit may result in. Method: This study has an inductive approach with a qualitative research method. The primary data was collected through semi-structured interviews with authorized auditors, authorized accountants and employees at Bolagsverket and Skatteverket. This empirical data was then analyzed and compared with earlier studies to answer our research question. Result &amp; Conclusions: This study shows that increased thresholds may impact the quality of accounting, making it less reliable and useful, and it will also increase tax evasions. Even though it is complicated to say that these impacts only occur because of increased thresholds. The respondents express no particular concern if the thresholds are to be raised, since this will have very little impact on their work situation, except that existing laws will need to be looked over.   Suggestions for future research: We have determined that since only a short time has passed, it is difficult to see any clear results of voluntary audit. A proposal for future research in this area is therefor to repeat this study a couple of years after the thresholds have been increased to establish more reliable results. Then, by using a larger sample of respondents, being able to present more opinions and thus a wider empirical point of view. Contribution of the thesis: This study has contributed to knowledge that can be of use for those companies that are considering whether or not they should implement voluntary audit. The study has among other things identified benefits of auditing and the impact increased thresholds may have on accounting.

Dans cette thèse je travaille sur la relation entre la pluviosité et l’érosion fluviatile en utilisant une approche probabiliste. Je développe une méthodologie indépendante de la moyenne pour caractériser la variabilité de la pluviosité journalière.L’indépendance vis-à-vis de la moyenne permet une comparaison simpleetobjectivedelavariabilitédelapluviosité sous différents régimes climatiques. Elle semontre également utile pour intégrer le concept de variabilité de la pluviosité dans lathéorie que je développe ensuite. J’applique cette approche à la chaine de montagnesHimalayenne en utilisant des données de pluviosité de hautes résolutions spatiale ettemporelle et trouve qu’il existe des variations significatives de la variabilité de la pluviositédans l’Himalaya. En prenant en compte la variabilité de la pluviosité en plusde la pluviosité moyenne, je trouve un lien entre pluviosité et érosion qui, d’un pointde vue géomorphologique, diffère, de façon significative, de celui déduit de la seulepluviosité moyenne.Ensuite, je développe une théorie d’érosion fluviatile du type ’puissance de flux‘ quicomprend une paramétrisation réaliste de la pluviosité et de l’hydrologie. Ceci estréalisé en intégrant un modèle hydrologique stochastique-mécaniste bien établi dansune formulation stochastique de la puissance de flux comprenant un seuil. La théoriehydrologique conduit à des expressions mathématiques pour la distribution et la variabilitédu débit journalier en fonction des conditions climatiques qui sont valablespour la majorité des régimes de débit observés à la surface de la Terre. Les nouveauxparamètres qui en découlent ont une signification bien ancrée dans des théories climatiqueet hydrologique établies et se mesurent facilement. Cette approche nous permetde prédire comment le taux d’érosion fluviatile répond à des changements du forçageclimatique. Je trouve ainsi que les processus hydrologiques peuvent avoir une influencesignificative sur l’efficacité érosive d’un forçage climatique donné. Cette approchepeut également être utilisée comme fondement de nouveaux modèles d’évolution desreliefs qui prennent en compte des conditions aux limites climatique et hydrologique.Une des principales conséquences d’intégrer l’hydrologie dans le modèle de puissancede flux est de révéler le double effet de la moyenne et de la variabilité du forçage climatiquesur la réponse écohydrologique. Une corrélation négative existe entre la moyenneet la variabilité qui restreint grandement les réponses possibles d’un bassin versant àdes changements climatiques. L’approche théorique que j’ai développée décrit égalementles relations qui relient la variabilité journalière à plusieurs paramètres écohydroclimatiques.Je trouve ainsi que l’index d’aridité, le temps de réponse du bassin versant,et l’épaisseur effective de sol sont les contrôles les plus importants sur la variabilité dudébit. Ceci a d’importantes conséquences pour le rôle que jouent l’hydrologie et lavégétation sur l’évolution des reliefs.Finalement, je démontre que l’influence de la variabilité journalière du forçage climatiquesur le taux d’érosion des rivières est principalement déterminée par l’existence et la valeur de seuils d’érosion. Je démontre que, quelques soient les détails du processus d’érosion considéré, c’est le rapport entre la valeur du seuil et la valeur moyenne du forçage climatique qui détermine si la variabilité compte ou pas, et dans quel sens.Parmi de nombreuses autres applications, ces découvertes contribuent à l’élaborationd’un nouveau cadre permettant de comprendre et prédire la réponse de la surface dela Terre à des changements de la moyenne et de la variabilité de la pluviosité et du débit des rivières. La généralité de ces découvertes a d’importantes implications pour le reste des travaux présentés dans la thèse, ainsi que pour les travaux antécédents sur le rôle de la variabilité de la pluviosité et du débit sur l’efficacité érosive des rivières. / In this thesis, we address the problem of how climate drives landscape evolution. Specifically, we work on the relationship between rainfall and fluvial erosion using a probabilistic approach. First we develop a mean-independent methodology to characterize the variability of daily rainfall. The mean-independent nature allows for simple, objective comparison of rainfall variability in climatically different regions. It also proves useful for integrating the concept of rainfall variability into theory. We apply this method over the Himalayan orogen using high spatial and temporal resolution rainfall data sets and find significant variations in rainfall variability over the Himalayan orogen. By taking into account variability of rainfall in addition to mean rainfall rate, we find a pattern of rainfall that, from a geomorphological perspective, is significantly different from mean rainfall rate alone. Next we develop of theory of stream power fluvial erosion that allows for realistically parameterized rainfall and hydrology. This is accomplished by integrating an established stochastic-mechanistic model of hydrology into a threshold-stochastic formulation of stream power. The hydrological theory provides equations for the daily streamflow distribution and variability as a function of climatic boundary conditions that are applicable across most of the observed range of streamflow regimes on Earth. The new parameters introduced are rooted firmly in established climatic and hydrological theory and are easily measured. This framework allows us to predict how fluvial erosion rates respond to changes in realistic rainfall forcing. We find that hydrological processes can have a significant influence on how erosive a particular climatic forcing will be. This framework can be used as a foundation for landscape evolution models that have realistic climatic and hydrological boundary conditions. One of the main strengths of integrating hydrology into the stream power model is to reveal the dependence of both streamflow mean and variability on the climatic forcing and ecohydrological response. This negative correlation of the mean and variability vastly restricts the likely responses of a river basin to changing climate. Our theoretical framework also describes the scaling daily variability with several other ecohydroclimatic parameters. We find that the aridity index, the basin response time, and the effective soil depth are the most important controls on discharge variability. This has important implications for the role of hydrology and vegetation in landscape evolution. Finally, we demonstrate that the way the Earth's surface responds to short-term climatic forcing variability is primarily determined by the existence and magnitude of erosional thresholds. We show that, irrespective of the nature of the erosional process, it is the ratio between the threshold magnitude and the mean magnitude of climatic forcing that determines whether variability matters or not and in which way. Among many other implications, our findings help provide a general framework to understand and predict the response of the Earth's surface to changes in mean and variability of rainfall and river discharge. The generality of this finding has important implications for the other work in this thesis, as well as previous work on role of rainfall and discharge variability on fluvial erosion.

This thesis examines the indirect impact of natural hazards on infrastructure networks. It addresses several key themes and issues for hazard assessment, network modelling and risk assessment using the case study of landslides impacting the national road network in Scotland, United Kingdom. The research follows four distinct stages. First, a landslide susceptibility model is developed using a database of landslide occurrences, spatial data sets and logistic regression. The model outputs indicate the terrain characteristics that are associated with increased landslide potential, including critical slope angles and south westerly aspects associated with increased rates of solar irradiance and precipitation. The results identify the hillslopes and road segments that are most prone to disruption by landslides and these indicate that 40 % (1,700 / 4,300 km) of Scotland s motorways and arterial roads (i.e. strategic road network) are susceptible to landslides and this is above previous assessments. Second, a novel user-equilibrium traffic model is developed using UK Census origin-destination tables. The traffic model calculates the additional travel time and cost (i.e. indirect impacts) caused by network disruptions due to landslide events. The model is applied to calculate the impact of historic scenarios and for sets of plausible landslide events generated using the landslide susceptibility model. Impact assessments for historic scenarios are 29 to 83 % greater than previous, including £1.2 million of indirect impacts over 15 days of disruption at the A83 Rest and Be Thankful landslide October 2007. The model results indicate that the average impact of landslides is £64 k per day of disruption, and up to £130 k per day on the most critical road segments in Scotland. In addition to identifying critical road segments with both high impact and high susceptibility to landslides, the study indicates that the impact of landslides is concentrated away from urban centres to the central and north-west regions of Scotland that are heavily reliant on road and haulage-based industries such as seasonal tourism, agriculture and craft distilling. The third research element is the development of landslide initiation thresholds using weather radar data. The thresholds classify the rainfall conditions that are most commonly associated with landslide occurrence in Scotland, improving knowledge of the physical initiation processes and their likelihood. The thresholds are developed using a novel optimal-point threshold selection technique, high resolution radar and new rain variables that provide spatio-temporally normalised thresholds. The thresholds highlight the role of the 12-day antecedent hydrological condition of soils as a precursory factor in controlling the rain conditions that trigger landslides. The new results also support the observation that landslides occur more frequently in the UK during the early autumn and winter seasons when sequences or clustering of multiple cyclonic-storm systems is common in periods lasting 5 to 15 days. Fourth, the three previous elements are combined to evaluate the landslide hazard of the strategic road segments and a prototype risk assessment model is produced - a catastrophe model. The catastrophe model calculates the annual average loss and aggregated exceedance probability of losses due to the indirect impact of landslides in Scotland. Beyond application to cost-benefit analyses for landslide mitigation efforts, the catastrophe model framework is applicable to the study of other natural hazards (e.g. flooding), combinations of hazards, and other infrastructure networks.

The present article provides first microlevel (indirect) empirical evidence on changes in entry barriers, the determinants of firm profitability as well as the nature of competition for a transition economy. We estimate size thresholds required to support different numbers of firms for several retail and professional service industries in a large number of geographic markets in Slovakia. The 3 time periods in the analysis (1995, 2001 and 2010) characterize different stages of the transition process. Specific emphasis is given to spatial spill-over effects between local markets. Estimation results obtained from a spatial ordered probit model suggest that entry barriers have declined considerably (except for restaurants) and that the intensity of competition has increased on average. We further find that demand spill-overs and/or the effects associated with a positive correlation in unobservable explanatory variables seem to outweigh negative spill-over effects caused by competitive forces between neighbouring cities and villages. The importance of these spatial spill-over effects differs across industries.

Doctor of Philosophy / Department of Geography / John A. Harrington Jr / The climate of the Middle East is warming and extreme hot temperature events are becoming more common, as observed by the significant upward trends in mean and extreme temperatures during the last few decades. Climate modeling studies suggest that the frequency, intensity, and duration of extreme temperature events are expected to increase as the global and local climate continues to warm. Existing literature about heat waves (HWs) in Saudi Arabia provides information about HW duration using a single index, without considering the observed effects of climate change and the subtropical arid climate. With that in mind, this dissertation provides a series of three stand-alone papers evaluating temporal, geographic, and atmospheric aspects of the character of warm season (May-September) HWs in Saudi Arabia for 1985 to 2014. Chapter 2 examines the temporal behavior(s) of the frequency, duration, and intensity of HWs under the observed recent climate change. Several issues are addressed including the identification of some improved methodological practices for HW indices. A time-sensitive approach to define and detect HWs is proposed and assessed. HW events and their duration are considered as count data; thus, different Poisson models were used for trend detection. Chapter 3 addresses the spatio-temporal patterns of the frequency and intensity of hot days and nights, and HWs. The chapter reemphasizes the importance of considering the on-goings effects of climate warming and applies a novel time-series clustering approach to recognize hot temperature event behavior through time and space. Chapter 4 explores the atmospheric circulation conditions that are associated with warm season HW event occurrence and how different HWs aspects are related to different circulation types. Further, possible teleconnections between HWs and sea surface temperature (SST) anomalies of nearby large bodies are examined. Results from Chapters 2 and 3 detected systematic upward trends in maximum and minimum temperatures at most of the 25 stations, suggesting an on-going change in the climatology of the upper-tail of the frequency distribution. The analysis demonstrated the value of using a time-sensitive approach in studying extreme thermal events. Different patterns were observed over time and space not only across stations but also among extreme temperature events (i.e., hot days and nights, and HWs). The overall results suggest that not only local and regional factors, such as elevation, latitude, land cover, atmospheric humidity, and distance from a large body of water, but also large-scale factors such as atmospheric circulation patterns are responsible for the observed temporal and spatial patterns. Chapter 4 confirmed that as the Indian Summer Monsoon Trough and the Arabian heat low were key atmospheric features related to HW days. SST anomalies seemed to be a more important factor for HWs intensity. Extreme thermal events in Saudi Arabia tended to occur during regional warming due to atmospheric circulation conditions and SSTs teleconnections. This study documents the value of a time-sensitive approach and should initiate further research as some of temporal and spatial variabilities were not fully explained