Predicting streamflow distributions and flow duration curves from landscape and climate

Characterizing the probability distribution of streamflows in catchments lacking in discharge measurements represents an attractive prospect with consequences for practical and scientific applications, in particular water resources management. In this paper, a physically-based analytic model of streamflow dynamics is combined with a set of water balance models and a geomorphological recession flow model in order to estimate streamflow probability distributions based on catchment-scale climatic and morphologic features. The models used are described and the novel parameterization approach is elaborated on. Starting from rainfall data, potential evapotranspiration and digital terrain maps, the method proved capable of capturing the statistics of observed streamflows reasonably well in 11 test catchments distributed throughout the United States, east of the rocky mountains. The method developed offers a unique approach for estimating probability distribution of streamflows where only climatic and geomorphologic features are known

Specificity of surface EMG recordings for gastrocnemius during upright standing.

The relatively large pick-up volume of surface electrodes has for long motivated the concern that muscles other than that of interest may contribute to surface electromyograms (EMGs). Recent findings suggest however the pick-up volume of surface electrodes may be smaller than previously appreciated, possibly leading to the detection of surface EMGs insensitive to muscle activity. Here we combined surface and intramuscular recordings to investigate how comparably action potentials from gastrocnemius and soleus are represented in surface EMGs detected with different inter-electrode distances. We computed the firing instants of motor units identified from intramuscular EMGs detected from gastrocnemius and soleus while five participants stood upright. We used these instants to trigger and average surface EMGs detected from multiple skin regions along gastrocnemius. Results from 66 motor units (whereof 31 from gastrocnemius) revealed the surface-recorded amplitude of soleus action potentials was 6% of that of gastrocnemius and did not decrease for inter-electrode distances smaller than 4 cm. Gastrocnemius action potentials were more likely detected for greater inter-electrode distances and their amplitude increased steeply up to 5 cm inter-electrode distance. These results suggest that reducing inter-electrode distance excessively may result in the detection of surface EMGs insensitive to gastrocnemius activity without substantial attenuation of soleus crosstalk

Detecting anatomical characteristics of single motor units by combining high density electromyography and ultrafast ultrasound: a simulation study

Muscle force production is the result of a sequence of electromechanical events that translate the neural drive issued to the motor units (MUs) into tensile forces on the tendon. Current technology allows this phenomenon to be investigated non-invasively. Single MU excitation and its mechanical response can be studied through high-density surface electromyography (HDsEMG) and ultrafast ultrasound (US) imaging respectively. In this study, we propose a method to integrate these two techniques to identify anatomical characteristics of single MUs. Specifically, we tested two algorithms, combining the tissue velocity sequence (TVS, obtained from ultrafast US images), and the MU firings (extracted from HDsEMG decomposition). The first is the Spike Triggered Averaging (STA) of the TVS based on the occurrences of individual MU firings, while the second relies on the correlation between the MU firing patterns and the TVS spatio-temporal independent components (STICA). A simulation model of the muscle contraction was adapted to test the algorithms at different degrees of neural excitation (number of active MUs) and MU synchronization. The performances of the two algorithms were quantified through the comparison between the simulated and the estimated characteristics of MU territories (size, location). Results show that both approaches are negatively affected by the number of active MU and synchronization levels. However, STICA provides a more robust MU territory estimation, outperforming STA in all the tested conditions. Our results suggest that spatio-temporal independent component decomposition of TVS is a suitable approach for anatomical and mechanical characterization of single MUs using a combined HDsEMG and ultrafast US approach

Water-energy-ecosystem nexus in small run-of-river hydropower : Optimal design and policy

Acknowledgment This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Support from the Helmholtz Centre for Environmental Research - UFZ is gratefully acknowledged.Peer reviewedPublisher PD

Upper limbs cranking for post-stroke rehabilitation: A pilot study on healthy subjects

Since one of the major consequences of stroke is hemiparesis, the rehabilitation of upper limbs is necessary to improve the quality of life. Arm cranking gesture represents an alternative rehabilitation tool, especially if accompanied by a biofeedback involving and motivating patients. The aim of this pilot study was twofold: (1) to evaluate the effect of a visual and virtual biofeedback on arm cranking gesture and (2) to estimate the duration of pull and push phases of the crank cycle. Nine healthy and young subjects were involved in the test and were asked to perform the arm cranking gesture in different conditions. A stereophotogrammetric system was adopted to create a virtual, visual and real time biofeedback of cadence, to measure the real cadence of participants and to estimate push and pull phases durations. Results showed that the biofeedback helped subjects to follow an externally imposed cadence. Furthermore, the pull phase resulted to be slightly longer than the push one, although the angular amplitude of the two phases suggested they were the same

Upper Limbs Musculoskeletal OpenSim Model: Customization and Assessment

Computational modelling is a powerful tool in biomechanical studies. Open-source software OpenSim provides different musculoskeletal models. However, existing upper body models consider only one limb, which could be a limitation in reproducing two-handed tasks. The purpose of this research was to develop a two upper limbs model that can be customized with subject’s anthropometry and muscles properties. The proposed model was composed of thorax, left and right upper limbs. Each limb presents 3 degrees of freedom (shoulder flexion-extension, elbow flexion-extension and prono-supination), 4 flexor and 3 extensor muscles. A preliminary model assessment was done. A subject was asked to execute isometric tests at three elbow angles, holding different loads, while EMG muscle activation was recorded. Simulated and experimental muscles activation were compared considering the right upper limb. Very good results were obtained without external load, whereas differences were observed when increasing the load; but, overall, model performance remained acceptable

Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics

Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is poor, with five year osteosarcoma survival rates in people not having improved in decades. For dogs, one year survival rates are only around ~45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human osteosarcoma. Finally, the current position of canine osteosarcoma genetic research is discussed and areas for additional work within the canine population are identified

Bone fragility and decline in stem cells in prematurely aging DNA repair deficient trichothiodystrophy mice

Trichothiodystrophy (TTD) is a rare, autosomal recessive nucleotide excision repair (NER) disorder caused by mutations in components of the dual functional NER/basal transcription factor TFIIH. TTD mice, carrying a patient-based point mutation in the Xpd gene, strikingly resemble many features of the human syndrome and exhibit signs of premature aging. To examine to which extent TTD mice resemble the normal process of aging, we thoroughly investigated the bone phenotype. Here, we show that female TTD mice exhibit accelerated bone aging from 39 weeks onwards as well as lack of periosteal apposition leading to reduced bone strength. Before 39 weeks have passed, bones of wild-type and TTD mice are identical excluding a developmental defect. Albeit that bone formation is decreased, osteoblasts in TTD mice retain bone-forming capacity as in vivo PTH treatment leads to increased cortical thickness. In vitro bone marrow cell cultures showed that TTD osteoprogenitors retain the capacity to differentiate into osteoblasts. However, after 13 weeks of age TTD females show decreased bone nodule formation. No increase in bone resorption or the number of osteoclasts was detected. In conclusion, TTD mice show premature bone aging, which is preceded by a decrease in mesenchymal stem cells/osteoprogenitors and a change in systemic factors, identifying DNA damage and repair as key determinants for bone fragility by influencing osteogenesis and bone metabolism

Abdominoplasty and Clitoris Evaluation: A Prospective Study on Sexual Pleasure in Women Undergoing Abdominoplasty

Introduction: Being one of the most practiced procedures in plastic surgery, it is important to foster a better understanding of the effect of anatomical changes in the pubic area after abdominoplasty on sexuality in women. Since to date no study has been performed with this purpose, our aim is to evaluate the impact of the abdominoplasty on sexual pleasure and to perform an objective evaluation of changes in clitoral position and prepubic fat area after this procedure. Materials and Methods: A prospective study has been performed in 50 women who expressed a desire to undergo abdominoplasty from January 2021 to December 2021. The primary endpoint was Sexual pleasure assessed by the "Sexuality Assessment Scale" before and 6 months after abdominoplasty in all patients. Furthermore, we evaluated the physical changes of the clitoris (clito-pubic distance, CP distance) and the prepubic fat area on magnetic resonance imaging before and 3 months after abdominoplasty. Results: Patients mean age was of 42 ± 9 years, and mean body mass index of 26 ± 2 kg/m2. A significant difference (P < 0.0001) between sexual satisfaction before and 6 months after abdominoplasty (mean difference +7.4 ± 6.452) was found. Though there was no significant difference between the clito-pubic distance before and after abdominoplasty (mean difference −3.200 ± 2.499 mm; p= 0.0832), a significant difference was found in the size of the prepubic fat area before compared to after abdominoplasty (mean difference −1.714 ± 1.010 cm2; p = 0.0426). However, no significant relationship between these anatomical changes and sexual satisfaction was found. Conclusion: Our results show that abdominoplasty is associated with an increase in sexual satisfaction. The changes in the post-operative position of the clitoris were not statistically significant, contrarily to the size of the prepubic fat area, which was significantly modified and could partially explain the improved sexual pleasure. Authors were unable to statistically demonstrate a correlation between those anatomical modifications and sexual pleasure. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266