Present and future water scarcity in Switzerland: Potential for alleviation through reservoirs and lakes.

In Alpine regions, future changes in glacier and snow cover are expected to change runoff regimes towards higher winter but lower summer discharge. The low summer discharge will coincide with the highest water demand for irrigation, and local and regional water shortages are expected to become more likely. One possible measure to adapt to these changes can be the extension of current uses of artificial reservoirs and natural lakes to the provision of water for the alleviation of water shortage. This study assesses the potential of reservoirs and natural lakes for the alleviation of water shortages in a nationwide analysis in Switzerland. To do so, we estimated water supply and demand under current and future conditions both under normal and extreme runoff regimes for 307 catchments. Water demand was assessed for various categories including drinking water, industrial use, artificial snow production, agriculture, ecological flow requirements, and hydropower production. The aggregated supply and demand estimates were used to derive water surplus/shortage estimates. These were then compared to the storage capacity of reservoirs and natural lakes within a catchment to determine the potential for alleviating summer water scarcity. Our results show that water shortage is expected mainly in the lowland region north of the Alps, and less in the Alps. In this lowland region, the potential of natural lakes for alleviating water scarcity is high. This potential is lower in the Alps where it is expected to increase or decrease under future conditions depending on the region of interest. Catchments with a high storage capacity can potentially contribute to the alleviation of water shortage downstream. We conclude that a spatial mismatch between water scarcity and storage availability exists since water stored in reservoirs on the southern side of the Alps is often not available for the use on the northern side.

Impact of spine alignment on the rotator cuff in long-term wheelchair users.

BACKGROUND: We investigated the impact of poor seated posture on the prevalence of rotator cuff tears (RCTs) among wheelchair-dependent individuals with long-standing paraplegia. METHODS: The study included 319 patients. Lateral radiographs of the spine were collected from a database and analyzed to assess the global spinopelvic alignment (SPA). Magnetic resonance images of both shoulders were obtained to detect the presence of cuff tears. Patients were divided into 2 groups: Group RCT-I included all patients with cuff tears (right, left, or bilateral), whereas group RCT-II consisted exclusively of patients with bilateral cuff tears. We used the classification systems developed by Kendall et al and Roussouly et al to assess the sagittal spine alignment and SPA, respectively. Univariate and multivariate analyses were performed. To fit both models (groups RCT-I and RCT-II) to the data, the 4 spine curves according to Roussouly et al were subdivided into 2 groups: Group SPA-I included both type 1 and type 2, whereas group SPA-II included both type 3 and type 4. RESULTS: Magnetic resonance images showed a cuff tear in 192 patients (60.19%) (group RCT-I). Among those, 37 patients (11.60%) had tears in both shoulders (group RCT-II). In group RCT-I, 70.31% of the patients had a kyphotic-lordotic posture. The kyphotic-lordotic posture, a longer duration, and a more rostral neurologic level of injury were highly associated with cuff tear prevalence. In group RCT-II, the multivariate analysis showed that only the duration of spinal cord injury was significantly associated with RCTs. CONCLUSION: Thoracic hyperkyphosis was associated with a markedly high rate of RCTs. The data from this study may provide support for developing preventive strategies.

Bivariate analysis of floods in climate impact assessments.

Climate impact studies regarding floods usually focus on peak discharges and a bivariate assessment of peak discharges and hydrograph volumes is not commonly included. A joint consideration of peak discharges and hydrograph volumes, however, is crucial when assessing flood risks for current and future climate conditions. Here, we present a methodology to develop synthetic design hydrographs for future climate conditions that jointly consider peak discharges and hydrograph volumes. First, change factors are derived based on a regional climate model and are applied to observed precipitation and temperature time series. Second, the modified time series are fed into a calibrated hydrological model to simulate runoff time series for future conditions. Third, these time series are used to construct synthetic design hydrographs. The bivariate flood frequency analysis used in the construction of synthetic design hydrographs takes into account the dependence between peak discharges and hydrograph volumes, and represents the shape of the hydrograph. The latter is modeled using a probability density function while the dependence between the design variables peak discharge and hydrograph volume is modeled using a copula. We applied this approach to a set of eight mountainous catchments in Switzerland to construct catchment-specific and season-specific design hydrographs for a control and three scenario climates. Our work demonstrates that projected climate changes have an impact not only on peak discharges but also on hydrograph volumes and on hydrograph shapes both at an annual and at a seasonal scale. These changes are not necessarily proportional which implies that climate impact assessments on future floods should consider more flood characteristics than just flood peaks.

Do overhead sports increase risk for rotator cuff tears in wheelchair users?

OBJECTIVE: To analyze whether frequent overhead-sports activity increases the risk for rotator cuff disease in patients with spinal cord injuries (SCIs) who are wheelchair dependent. DESIGN: Cross-sectional study, risk analysis. SETTING: Department of Orthopaedic Surgery, Trauma Surgery and Spinal Cord Injury. PARTICIPANTS: Patients (N=296) with SCI requiring the full-time use of a manual wheelchair were recruited for this study. The total population was divided into 2 groups (sports vs no sports), among them 103 patients playing overhead sports on a regular basis (at least 1-2 times/wk) and 193 patients involved in overhead sports less than once a week or in no sports activity at all. The mean age of the sports group was 49.1 years. The mean duration of wheelchair dependence was 26.5 years. The mean age of the no-sports group was 48 years. The mean duration of wheelchair dependence was 25.2 years. Each individual completed a questionnaire designed to identify overhead-sports activity on a regular basis and was asked about shoulder problems. Magnetic resonance imaging scans of both shoulders were performed in each patient and analyzed in a standardized fashion. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Possible differences in continuous data between patients with and without rotator cuff tear were evaluated. The relative risk of suffering from a rotator cuff tear between patients playing overhead sports and those not playing overhead sports was calculated. RESULTS: One hundred three patients played overhead sports regularly and 193 did not. There was no difference between groups regarding age, sex, level of SCI, and duration of wheelchair dependence. The body mass index was significantly lower in the sports group than in the no-sports group (P<.0001). A rotator cuff tear was present in 75.7% of the patients in the sports group and in 36.3% of the patients in the no-sports group (P<.0001). Rotator cuff tears were symptomatic in 92.6% of the patients. The estimated risk increase for the sports group to develop rotator cuff tears was twice as high as for the no-sports group (95% confidence interval, 1.7-2.6; P<.001). Similar results were found for the neurological level of lesion (T2-7/

Etiology of rotator cuff tears in paraplegic patients: a case-control study.

BACKGROUND: The purpose of this study was to investigate the etiology and the demographic and functional characteristics of rotator cuff tears (RCTs) in 100 paraplegic patients as compared with 100 able-bodied volunteers. METHODS: The magnetic resonance imaging examination results of 200 shoulders in each group were analyzed. Clinical examination included the Constant score and a visual analog scale for pain intensity. RESULTS: The prevalence of RCTs was 63% in paraplegic patients versus 15% in able-bodied volunteers (P < .0001). All RCTs in the paraplegic group were associated with symptoms. Among the patients with RCTs, full-thickness tears were detected in 78% of cases in the paraplegic patient group versus 73% of cases in the volunteer group. The rate of partial-thickness tears was 22% in the paraplegic group versus 27% in the volunteer group. Paraplegic patients had a lower Constant score; Disabilities of the Arm, Shoulder and Hand score; and range of motion and a higher pain intensity than the volunteer cohort. The mean tear width in paraplegic patients was 14.4 mm (range, 8-28 mm) versus 9.9 mm (range, 8-14 mm) in the volunteers (P < .01). CONCLUSION: The etiology of RCTs in paraplegic patients seems to be based on wear-and-tear mechanisms rather than aging. These results are important for our understanding of shoulder pathology in long-term paraplegic patients and show the impact of this problem.

A cross-sectional study of demographic and morphologic features of rotator cuff disease in paraplegic patients.

BACKGROUND: This study analyzed the demographic and morphologic features of rotator cuff disease in paraplegic patients who presented with or without shoulder pain. METHODS: Clinical and magnetic resonance imaging examinations of both shoulders were performed in 317 paraplegic patients. Mean age was 49 (range, 19-76) years. The level of spinal cord injury was between T2 and T7 In 54% of patients and between T8 and L3 in 46%. Constant scores were measured for all shoulders. Pain was analyzed using a visual analog scale. RESULTS: Rotator cuff tears were not present in 51%, were unilateral in 20%, and were bilateral in 29%. Age was older and duration of spinal cord injury was significantly longer in patients with bilateral tears than in patients without or with unilateral tears (P < .001). In patients with unilateral tears, a full-thickness rupture of the supraspinatus tendon was found in 67%, whereas a partial-rupture was detected in 33%. Of the patients with bilateral tears, 75% presented with a full-thickness rupture and 25% with a partial rupture. The mean Constant score was 76 (range, 37-98) in patients without cuff tears, 69 (range, 16-94) for patients with unilateral tears, and 64 (16-96) for patients with bilateral tears (P < .001). CONCLUSIONS: Rotator cuff disease is common and correlates highly with age and duration of spinal cord injury, which underlines the theory of "wear and tear" in wheelchair-dependent patients.

Prevalence of rotator cuff tear in paraplegic patients compared with controls.

BACKGROUND: Musculoskeletal injuries of the shoulder in paraplegic patients with long-term survival can result from overuse and/or inappropriate use of wheelchairs. The purpose of the present study was to evaluate the prevalence and risk of pathological changes in the weight-bearing shoulder girdle of paraplegic patients who have been wheelchair-dependent for more than thirty years in comparison with able-bodied volunteers. METHODS: One hundred paraplegic patients were matched for sex and age with a group of 100 able-bodied volunteers. Two hundred shoulders from each group were evaluated with use of magnetic resonance imaging. Collected outcome measures included a standardized clinical examination protocol, the Constant score, and a visual analog score for pain intensity. RESULTS: Shoulder function according to the Constant score was significantly worse in the paraplegic patients than in the able-bodied volunteers. Similarly, the visual analog scale pain scores were significantly worse for the paraplegic patients. Magnetic resonance imaging showed that the prevalence of rotator cuff tears in either shoulder was significantly higher in the paraplegic patients than in the able-bodied volunteers (63% compared with 15%), resulting in a tenfold higher risk of rotator cuff rupture among paraplegic patients. CONCLUSIONS: The present study demonstrates that the structural and functional changes of the shoulder joint are more severe and the risk of development of shoulder girdle damage is significantly higher in individuals with long-term paraplegia than in age-matched controls.