Articoli di riviste: "Restriction tidale"

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Khojasteh, Danial, Steve Hottinger, Stefan Felder, Giovanni De Cesare, Valentin Heimhuber, David J. Hanslow e William Glamore. "IMPACT OF SEA LEVEL RISE ON HYDRODYNAMICS OF ESTUARIES WITH RESTRICTED ENTRANCES". Coastal Engineering Proceedings, n. 36v (28 dicembre 2020): 3. http://dx.doi.org/10.9753/icce.v36v.management.3.

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Worldwide, hundreds of millions of people who live on or near estuarine environments are vulnerable to sea level rise (SLR). Using clustering techniques and moving beyond static models and case studies, this study used a large ensemble of idealised estuary models of varying scale, geometry, level of entrance constriction, and SLR scenarios. It was found that tidal forcing, degree of entrance restriction, and estuarine length can primarily control the tidal dynamics of prismatic estuaries under SLR. Further, restricting an entrance can be presented as a potential solution to offset SLR induced tidal amplification if the associated impacts on entrance stability, navigation, and flooding are considered.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/vOptOAbqN3U

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O'Donnell, Denis E., Harry H. Hong e Katherine A. Webb. "Respiratory sensation during chest wall restriction and dead space loading in exercising men". Journal of Applied Physiology 88, n. 5 (1 maggio 2000): 1859–69. http://dx.doi.org/10.1152/jappl.2000.88.5.1859.

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We mimicked important mechanical and ventilatory aspects of restrictive lung disorders by employing chest wall strapping (CWS) and dead space loading (DS) in normal subjects to gain mechanistic insights into dyspnea causation and exercise limitation. We hypothesized that thoracic restriction with increased ventilatory stimulation would evoke exertional dyspnea that was similar in nature to that experienced in such disorders. Twelve healthy young men [28 ± 2 (SE) yr of age] completed pulmonary function tests and maximal cycle exercise tests under four conditions, in randomized order: 1) control, 2) CWS to 60% of vital capacity, 3) added DS of 600 ml, and 4) CWS + DS. Measurements during exercise included cardiorespiratory parameters, esophageal pressure, and Borg scale ratings of dyspnea. Compared with control, CWS significantly reduced the tidal volume response to exercise, increased dyspnea intensity at any given work rate or ventilation, and thus limited exercise performance. DS stimulated ventilation but had minimal effects on dyspnea and exercise performance. Adding DS to CWS further increased dyspnea by 1.7 ± 0.6 standardized Borg units ( P = 0.012) and decreased exercise performance (total work) by 21 ± 6% ( P = 0.003) over CWS alone. Across conditions, increased dyspnea intensity correlated best with decreased resting inspiratory reserve volume ( r = −0.63, P < 0.0005). Dyspnea during CWS was described primarily as “inspiratory difficulty” and “unsatisfied inspiration,” similar to restrictive disorders. In conclusion, severe dyspnea and exercise intolerance were provoked in healthy normal subjects when tidal volume responses were constrained in the face of increased ventilatory drive during exercise.

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Harty, Helen R., Douglas R. Corfield, Richard M. Schwartzstein e Lewis Adams. "External thoracic restriction, respiratory sensation, and ventilation during exercise in men". Journal of Applied Physiology 86, n. 4 (1 aprile 1999): 1142–50. http://dx.doi.org/10.1152/jappl.1999.86.4.1142.

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Multiple factors may contribute to the dyspnea associated with restrictive ventilatory disease (RVD). Simple models that examine specific features of this problem are likely to provide insight into the mechanisms. Previous models of RVD utilizing elastic loads may not represent completely the impact on pulmonary and chest wall receptors derived from breathing at low thoracic volumes. The purpose of this study was to investigate the sensory consequences of breathing at low lung volumes induced by external thoracic restriction in an attempt to further elucidate the etiology of dyspnea in this setting. Ten men were studied, with and without an inelastic corset applied at residual volume (restriction resulted in mean reductions in vital capacity, functional residual capacity, residual volume, and forced expired volume in 1 s of 44, 31, 12.5, and 42%, respectively). During 10-min steady-state exercise tests (at a workload set to achieve ∼65% maximum heart rate), restriction resulted in significant increases, compared with control, in minute ventilation (61 vs. 49 l/min), respiratory frequency (43 vs. 23 breaths/min), and visual analog scale measurements of respiratory discomfort (65 vs. 20 mm). Alveolar hyperventilation (end-tidal [Formula: see text] = 39 vs. 44 Torr for control) and mild O2 desaturation (arterial blood O2 saturation = 93 vs. 95% for control) occurred. Hypoxemia, atelectasis, increased work and effort of breathing, or a decrease in the volume-related feedback from chest wall and/or lungs could be responsible for the increased dyspnea reported. External thoracic restriction provides a useful model to study mechanisms of dyspnea in RVD.

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Nuyts, Siegmund, Melissa Wartman, Peter I. Macreadie e Micheli D. P. Costa. "Mapping tidal restrictions to support blue carbon restoration". Science of The Total Environment 949 (novembre 2024): 175085. http://dx.doi.org/10.1016/j.scitotenv.2024.175085.

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Dick, Todd M., e Olusegun O. Osunkoya. "Influence of tidal restriction floodgates on decomposition of mangrove litter". Aquatic Botany 68, n. 3 (novembre 2000): 273–80. http://dx.doi.org/10.1016/s0304-3770(00)00119-4.

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Ferreira, Rafael M., e Segen F. Estefen. "Alternative concept for tidal power plant with reservoir restrictions". Renewable Energy 34, n. 4 (aprile 2009): 1151–57. http://dx.doi.org/10.1016/j.renene.2008.08.014.

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Muñuzuri, Jesús, Elena Barbadilla, Alejandro Escudero-Santana e Luis Onieva. "Planning Navigation in Inland Waterways with Tidal Depth Restrictions". Journal of Navigation 71, n. 3 (16 novembre 2017): 547–64. http://dx.doi.org/10.1017/s0373463317000789.

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The planning of vessel navigation along a tidal river is a complex task that can affect the efficiency of inland ports and intermodal chains. The availability of water may represent a significant restriction to port accessibility, having an impact on waiting times, cost and even safety. This paper presents a heuristic procedure to schedule vessels on a tidal waterway, which seeks to optimise navigation according to a multi-criteria objective function combining the number of vessels serviced, the total waiting time, the waterway occupation time and the number of crossing operations, where the term “crossing” implies inbound and outbound vessels passing each other. The procedure requires a previous step of estimation of real-time water depth, which identifies the critical points or navigation bottlenecks along the waterway, and contemplates the possibility of vessels having to anchor in the middle of their journey and wait for next tide rise. We validate the procedure through its application to a set of real and test problems and show that its results are reliable in terms of performance and solution quality.

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Yanai, M., K. Sekizawa, H. Sasaki e T. Takishima. "Control of the larynx in patients with obstructive and restrictive pulmonary impairment". European Respiratory Journal 2, n. 1 (1 gennaio 1989): 31–35. http://dx.doi.org/10.1183/09031936.93.02010031.

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To study changes in glottic movements associated with pulmonary functional abnormalities, we measured changes in glottic resistance (Rgl) during quiet tidal breathing in normal subjects (N), patients with chronic obstructive pulmonary disease (COPD) and patients with idiopathic pulmonary fibrosis (IPF). Changes in Rgl were measured with a non-invasive method using low frequency sound. Changes in Rgl were tightly coupled to changes in tidal volume and were reproducible in all subjects. Rgl was higher during expiration than during inspiration in N and COPD. COPD showed greater changes in Rgl between inspiration and expiration than did N. However, Rgl did not differ between inspiration and expiration in three of six IPF, and was lower during expiration than during inspiration in two of six IPF. We suggest that glottic movements during quiet tidal breathing change in association with the functional abnormalities of pulmonary diseases.

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Khojasteh, Danial, Steve Hottinger, Stefan Felder, Giovanni De Cesare, Valentin Heimhuber, David J. Hanslow e William Glamore. "Estuarine tidal response to sea level rise: The significance of entrance restriction". Estuarine, Coastal and Shelf Science 244 (ottobre 2020): 106941. http://dx.doi.org/10.1016/j.ecss.2020.106941.

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Rueda-Bayona, Juan Gabriel, José Luis García Vélez e Daniel Mateo Parrado-Vallejo. "Effect of Sea Level Rise and Access Channel Deepening on Future Tidal Power Plants in Buenaventura Colombia". Infrastructures 8, n. 3 (13 marzo 2023): 51. http://dx.doi.org/10.3390/infrastructures8030051.

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The evolution of tidal stream turbines is increasing the feasibility of future tidal plants in shallow depth areas with mid-tidal ranges (<5 m). However, extreme events such as changes in bathymetry due to the access channel deepening of coastal ports and sea level rise modify hydrodynamics and might affect the infrastructure and energy production of tidal energy converters. This research focused on Buenaventura Bay to analyze the effect of these extreme events on marine currents through calibrated-validated numerical modeling. Several monitored points were analyzed, and the results highlighted that the bay has potential for implementing tidal stream turbines because of the reported velocities between 0.25 and 2 m/s. The sea level rise increased 11.39% and access channel deepening reduced by 17.12% the velocity currents of the bay, respectively. These findings convert Buenaventura Bay to a candidate for implementing third generation tidal stream turbines and motivate future research for implementing tidal power systems in crucial areas such as the Colombian Pacific, where communities face restrictions in accessing affordable and clean energy.

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PORTNOY, JOHN W., e JENNY R. ALLEN. "EFFECTS OF TIDAL RESTRICTIONS AND POTENTIAL BENEFITS OF TIDAL RESTORATION ON FECAL COLIFORM AND SHELLFISH-WATER QUALITY". Journal of Shellfish Research 25, n. 2 (agosto 2006): 609–17. http://dx.doi.org/10.2983/0730-8000(2006)25[609:eotrap]2.0.co;2.

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Maugé, R., e T. Gerkema. "Generation of weakly nonlinear nonhydrostatic internal tides over large topography: a multi-modal approach". Nonlinear Processes in Geophysics 15, n. 2 (7 marzo 2008): 233–44. http://dx.doi.org/10.5194/npg-15-233-2008.

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Abstract. A set of evolution equations is derived for the modal coefficients in a weakly nonlinear nonhydrostatic internal-tide generation problem. The equations allow for the presence of large-amplitude topography, e.g. a continental slope, which is formally assumed to have a length scale much larger than that of the internal tide. However, comparison with results from more sophisticated numerical models show that this restriction can in practice be relaxed. It is shown that a topographically induced coupling between modes occurs that is distinct from nonlinear coupling. Nonlinear effects include the generation of higher harmonics by reflection from boundaries, i.e. steeper tidal beams at frequencies that are multiples of the basic tidal frequency. With a seasonal thermocline included, the model is capable of reproducing the phenomenon of local generation of internal solitary waves by a tidal beam impinging on the seasonal thermocline.

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Chen, Yuqing, Yueyang Yuan, Hai Zhang, Feng Li e Xin Zhou. "Accuracy of the dynamic signal analysis approach in respiratory mechanics during noninvasive pressure support ventilation: a bench study". Journal of International Medical Research 49, n. 2 (febbraio 2021): 030006052199218. http://dx.doi.org/10.1177/0300060521992184.

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Objective To evaluate the accuracy of respiratory mechanics using dynamic signal analysis during noninvasive pressure support ventilation (PSV). Methods A Respironics V60 ventilator was connected to an active lung simulator to model normal, restrictive, obstructive, and mixed obstructive and restrictive profiles. The PSV was adjusted to maintain tidal volumes (VT) that achieved 5.0, 7.0, and 10.0 mL/kg body weight, and the positive end-expiration pressure (PEEP) was set to 5 cmH2O. Ventilator performance was evaluated by measuring the flow, airway pressure, and volume. The system compliance (Crs) and airway resistance (inspiratory and expiratory resistance, Rinsp and Rexp, respectively) were calculated. Results Under active breathing conditions, the Crs was overestimated in the normal and restrictive models, and it decreased with an increasing pressure support (PS) level. The Rinsp calculated error was approximately 10% at 10.0 mL/kg of VT, and similar results were obtained for the calculated Rexp at 7.0 mL/kg of VT. Conclusion Using dynamic signal analysis, appropriate tidal volume was beneficial for Rrs, especially for estimating Rexp during assisted ventilation. The Crs measurement was also relatively accurate in obstructive conditions.

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Plummer, Andrew R., Jonathan L. du Bois, Joseph M. Flynn, Jens Roesner, Siu Man Lee, Patrick Magee, Malcolm Thornton, Andrew Padkin e Harinderjit S. Gill. "A simple method to estimate flow restriction for dual ventilation of dissimilar patients: The BathRC model". PLOS ONE 15, n. 11 (16 novembre 2020): e0242123. http://dx.doi.org/10.1371/journal.pone.0242123.

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Background With large numbers of COVID-19 patients requiring mechanical ventilation and ventilators possibly being in short supply, in extremis two patients may have to share one ventilator. Careful matching of patient ventilation requirements is necessary. However, good matching is difficult to achieve as lung characteristics can have a wide range and may vary over time. Adding flow restriction to the flow path between ventilator and patient gives the opportunity to control the airway pressure and hence flow and volume individually for each patient. This study aimed to create and validate a simple model for calculating required flow restriction. Methods and findings We created a simple linear resistance-compliance model, termed the BathRC model, of the ventilator tubing system and lung allowing direct calculation of the relationships between pressures, volumes, and required flow restriction. Experimental measurements were made for parameter determination and validation using a clinical ventilator connected to two test lungs. For validation, differing amounts of restriction were introduced into the ventilator circuit. The BathRC model was able to predict tidal lung volumes with a mean error of 4% (min:1.2%, max:9.3%). Conclusion We present a simple model validated model that can be used to estimate required flow restriction for dual patient ventilation. The BathRC model is freely available; this tool is provided to demonstrate that flow restriction can be readily estimated. Models and data are available at DOI 10.15125/BATH-00816.

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Rojanapairat, Oragun, Abigail Beggs, Melisa Chang e Aaron Thomas. "1235 REM Sleep Associated Hypoventilation". Sleep 43, Supplement_1 (aprile 2020): A471. http://dx.doi.org/10.1093/sleep/zsaa056.1229.

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Abstract Introduction Hypoventilation is a spectrum of respiratory disorders that is frequently found in patients with chronic obstructive pulmonary disease, restrictive lung disease (eg obesity, neuromuscular, severe interstitial lung disease, and chest wall disease), chronic sedative use, and hypothyroidism. Rapid eye movement (REM) sleep hypoventilation may be the first manifestation of hypoventilation prior to development of non-REM sleep hypoventilation and eventual awake alveolar hypoventilation. We present a case of hypoventilation during REM sleep with mild restriction on pulmonary function testing, prior to the development of obesity hypoventilation syndrome (OHS). Report of Case 68-year-old male with past medical history of diastolic heart failure, class Ill obesity (BMI 46), hypertension, chronic kidney disease lllb, and diabetes mellitus underwent split night polysomnography for evaluation of snoring, witnessed apneas and excessive daytime sleepiness. The study was significant for an apnea hypopnea index of 105/hour, and REM sleep sustained desaturation to a nadir of 72% without apneas or hypopneas, suspicious for hypoventilation. The derangements during REM sleep did not correct during PAP titration despite CPAP and supplemental oxygen. End tidal capnography was not available for the study. Follow up PFT demonstrated normal spirometry, mild restrictive lung volumes, ERV 27%, and severely depressed DLCO which corrected for alveolar volume. Daytime arterial blood gas did not reveal hypercapnia or hypoxemia (7.37/39/78/23). He underwent successful nocturnal titration with average volume assured pressure support with the final settings of IPAP 24-30, EPAP 20, VT 560 (8 ml/kg IBW), rate of 12 breaths per minute and no supplemental oxygen. Conclusion This patient demonstrates REM sleep hypoventilation without overt OHS during all stages of sleep, which likely would progress to OHS over time. OHS is associated with increased rates of chronic heart failure, pulmonary hypertension, hospitalizations for respiratory failure, and mortality. Early recognition and treatment are important in improving morbidity and mortality.

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Moreno-Valcárcel, R., FJ Oliva-Paterna, S. Bevilacqua, A. Terlizzi e C. Fernández-Delgado. "Long-term effects of tidal restriction on fish assemblages in east Atlantic coastal marshlands". Marine Ecology Progress Series 543 (3 febbraio 2016): 209–22. http://dx.doi.org/10.3354/meps11578.

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Raposa, Kenneth B., e Charles T. Roman. "Using gradients in tidal restriction to evaluate nekton community responses to salt marsh restoration". Estuaries 26, n. 1 (febbraio 2003): 98–105. http://dx.doi.org/10.1007/bf02691697.

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Sun, Shucun, Yongli Cai e Xingjun Tian. "Salt marsh vegetation change after a short-term tidal restriction in the Changjiang estuary". Wetlands 23, n. 2 (giugno 2003): 257–66. http://dx.doi.org/10.1672/5-20.

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Qi, Man, Tao Sun, Min Zhan e SuFeng Xue. "Simulating Dynamic Vegetation Changes in a Tidal Restriction Area with Relative Stress Tolerance Curves". Wetlands 36, S1 (12 febbraio 2015): 31–43. http://dx.doi.org/10.1007/s13157-015-0639-1.

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Costa, L. Filipe O., e Carlos A. R. Herdeiro. "Reference frames and the physical gravito-electromagnetic analogy". Proceedings of the International Astronomical Union 5, S261 (aprile 2009): 31–39. http://dx.doi.org/10.1017/s1743921309990111.

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AbstractThe similarities between linearized gravity and electromagnetism are known since the early days of General Relativity. Using an exact approach based on tidal tensors, we show that such analogy holds only on very special conditions and depends crucially on the reference frame. This places restrictions on the validity of the “gravito-electromagnetic” equations commonly found in literature.

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Degraeuwe, P. L. J., G. D. Vos e C. E. Blanco. "Perfluorochemical Liquid Ventilation: From the Animal Laboratory to the Intensive Care Unit". International Journal of Artificial Organs 18, n. 10 (ottobre 1995): 674–83. http://dx.doi.org/10.1177/039139889501801020.

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Perfluorochemical or perfluorocarbon liquids have an enormous gas-carrying capacity. During tidal liquid ventilation the respiratory medium of both functional residual capacity and tidal volume is replaced by neat perfluorocarbon liquid. Tidal liquid ventilation is characterized by convective and diffusive limitations, but offers the advantage of preserved functional residual capacity, high compliance and improved ventilation-perfusion matching. During partial liquid ventilation only the functional residual capacity is replaced by perfluorocarbon liquid. Both tidal and partial liquid ventilation improve gas exchange and lung mechanics in hyaline membrane disease, adult respiratory distress models and meconium aspiration. Compared to gas ventilation, there is less histologic evidence of barotrauma after liquid ventilation. Cardio-pulmonary interaction, inherent to the high density of liquid, and long term safety need further study. However, extrapolating from animal data, and taking into account promising human pilot studies, liquid ventilation has the desired properties to occupy an important place in the therapy of restrictive lung disease in man.

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Mendonca, Cassandra T., Michele R. Schaeffer, Patrick Riley e Dennis Jensen. "Physiological mechanisms of dyspnea during exercise with external thoracic restriction: Role of increased neural respiratory drive". Journal of Applied Physiology 116, n. 5 (1 marzo 2014): 570–81. http://dx.doi.org/10.1152/japplphysiol.00950.2013.

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We tested the hypothesis that neuromechanical uncoupling of the respiratory system forms the mechanistic basis of dyspnea during exercise in the setting of “abnormal” restrictive constraints on ventilation (VE). To this end, we examined the effect of chest wall strapping (CWS) sufficient to mimic a “mild” restrictive lung deficit on the interrelationships between VE, breathing pattern, dynamic operating lung volumes, esophageal electrode-balloon catheter-derived measures of the diaphragm electromyogram (EMGdi) and the transdiaphragmatic pressure time product (PTPdi), and sensory intensity and unpleasantness ratings of dyspnea during exercise. Twenty healthy men aged 25.7 ± 1.1 years (means ± SE) completed symptom-limited incremental cycle exercise tests under two randomized conditions: unrestricted control and CWS to reduce vital capacity (VC) by 21.6 ± 0.5%. Compared with control, exercise with CWS was associated with 1) an exaggerated EMGdi and PTPdi response; 2) no change in the relationship between EMGdi and each of tidal volume (expressed as a percentage of VC), inspiratory reserve volume, and PTPdi, thus indicating relative preservation of neuromechanical coupling; 3) increased sensory intensity and unpleasantness ratings of dyspnea; and 4) no change in the relationship between increasing EMGdi and each of the intensity and unpleasantness of dyspnea. In conclusion, the increased intensity and unpleasantness of dyspnea during exercise with CWS could not be readily explained by increased neuromechanical uncoupling but likely reflected the awareness of increased neural respiratory drive (EMGdi) needed to achieve any given VE during exercise in the setting of “abnormal” restrictive constraints on tidal volume expansion.

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Duncan, S. R., F. T. Kagawa, M. R. Kramer, V. A. Starnes e J. Theodore. "Effects of pulmonary restriction on hypercapnic responses of heart-lung transplant recipients". Journal of Applied Physiology 71, n. 1 (1 luglio 1991): 322–27. http://dx.doi.org/10.1152/jappl.1991.71.1.322.

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Previous studies of hypercapnic ventilatory responses (HCVR) in human heart-lung transplant recipients (HLTX) have yielded conflicting results. We compared the HCVR of restricted transplant recipients (HLTX-R) to recipients with normal pulmonary function (HLTX-N), and normal controls (C). HLTX-R exhibited limited tidal volume responses, whereas their frequency responses were essentially identical to those of other subjects. Accordingly, HCVR of HLTX-R (1.45 +/- 0.59 l.min-1.Torr CO2(-1)) were significantly depressed compared with both HLTX-N and C (2.90 +/- 0.55 vs 3.05 +/- 1.23, respectively) (P less than 0.02). Despite undoubtedly greater ventilatory impedances, airway (mouth) occlusion pressure responses (Pm0.1) during hypercarbia of HLTX-R (0.46 +/- 0.28 cmH2O) were similar to those of C (0.43 +/- 0.20) and paradoxically blunted compared with HLTX-N (0.83 +/- 0.36) (P less than 0.02). We conclude that pulmonary reflexes are superfluous for maintenance of HCVR in HLTX with normal respiratory mechanics, whereas the presence of moderate restriction results in profound depression of CO2 responses among these subjects.

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Vazquez, Angela, e Gregorio Iglesias. "A HOLISTIC METHOD TO SELECT TIDAL STREAM ENERGY HOTSPOTS". Coastal Engineering Proceedings, n. 35 (23 giugno 2017): 5. http://dx.doi.org/10.9753/icce.v35.management.5.

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Potential areas for tidal stream energy development are conventionally selected on the basis of resource assessments. For all the importance of the resource, there are other elements (technological, economic, spatial, etc.) that must be taken into account in this selection. The objective of the present work is to develop a new methodology to select tidal stream hotspots accounting for all these relevant elements, and to apply it to a case study, showing in the process how the potential for tidal energy development can be fundamentally altered by technological, economic and spatial constraints. The case study is conducted in the Bristol Channel and Severn Estuary (UK), one of the regions with the largest tidal resource in the world. First, the most energetic areas are identified by means of a hydrodynamics model, calibrated and validated with field data. Second, the method calculates the energy that can be harnessed in these areas by means of a geospatial Matlab-based program designed ad hoc, and on the basis of the power curve and dimensions of a specific tidal turbine. Third, the spatial distribution of the levelised cost of energy (LCOE) is calculated, and a number of locations are selected as potential tidal sites. The fourth element in the approach is the consideration of restrictions due to overlap with other marine uses, such as shipping. As a result, potential conflict-free areas for tidal stream energy exploitation at an economical cost are identified. Thus, the case study illustrates this holistic approach to selecting tidal stream sites and the importance of elements other than the resource, which â€“ for all its relevance â€“ is shown to not guarantee by itself the potential for tidal stream energy development.

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Karberg, Jennifer. "Salinity Tolerance of Common Reed (Phragmites australis) at the Medouie Creek Restoration Site, Nantucket MA". Wetland Science & Practice 31, n. 1 (marzo 2015): 19–23. http://dx.doi.org/10.1672/ucrt083-284.

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I n 2008, the Nantucket Conservation Foundation (NCF) initiated a salt marsh restoration project at the Medouie Creek Wetland Complex, Nantucket, Massachusetts. This involved installing a box culvert under a restrictive dike road to reconnect tidal, saltwater hydrology throughout the marsh, in which the restricted portion had converted to freshwater conditions sometime in the 1930s.

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Amorim, D. O., e T. V. Gudkova. "Internal Structure of Venus Based on the PREM Model". Solar System Research 57, n. 5 (ottobre 2023): 414–25. http://dx.doi.org/10.1134/s0038094623040020.

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Abstract— Models of the internal structure of Venus have been constructed with a wide range of crustal thickness (30–70 km) and core radius (2800–3500 km). An analysis of the pressure values in the center of the planet allows us to conclude that the presence of a solid inner core is unlikely if the composition and temperature profile of Venus correspond to that of the Earth. Andrade’s rheology was used to take into account the inelasticity of the interior of Venus when calculating the tidal Love numbers and the angle of delay of the tidal hump. Comparison of experimental values of the Love number k2 with the model gives the radius of the core of Venus in the range of 3100–3500 km. It is shown that to determine the characteristic viscosity of the Venusian mantle, the key factor is the determination of the angle of retardation of the tidal bulge: values of 0.9° correspond to low viscosity and high temperature, and 0.4° to high viscosity and low temperature, so the planned measurements of tidal parameters and the moment of inertia of the planet in the VERITAS and EnVision missions will be able to impose restrictions on the distribution of viscosity and temperature in the interior of Venus.

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Amorim, D. O., e T. V. Gudkova. "Internal Structure of Venus Based on the PREM Model". Астрономический вестник 57, n. 5 (1 settembre 2023): 403–14. http://dx.doi.org/10.31857/s0320930x23040023.

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Abstract (sommario):

Models of the internal structure of Venus have been constructed with a wide range of crustal thickness (30–70 km) and core radius (2800–3500 km). An analysis of the pressure values in the center of the planet allows us to conclude that the presence of a solid inner core is unlikely if the composition and temperature profile of Venus correspond to that of the Earth. Andrade’s rheology was used to take into account the inelasticity of the interior of Venus when calculating the tidal Love numbers and the angle of delay of the tidal hump. Comparison of experimental values of the Love number k2 with the model gives the radius of the core of Venus in the range of 3100–3500 km. It is shown that to determine the characteristic viscosity of the Venusian mantle, the key factor is the determination of the angle of retardation of the tidal bulge: values of 0.9° correspond to low viscosity and high temperature, and 0.4° to high viscosity and low temperature, so the planned measurements of tidal parameters and the moment of inertia of the planet in the VERITAS and EnVision missions will be able to impose restrictions on the distribution of viscosity and temperature in the interior of Venus.

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Zhang, Haifeng, Lin Zhao, Wen Du, Qing Liu, Yifei Zhao e Min Xu. "Research on the Limit Values of Reclamation Based on Ecological Security: A Case Study of Tongzhou Bay in Rudong, Jiangsu Province". International Journal of Environmental Research and Public Health 19, n. 14 (7 luglio 2022): 8301. http://dx.doi.org/10.3390/ijerph19148301.

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Abstract (sommario):

Due to the growing demand for land resources, many coastal reclamation projects have been implemented around the world in recent decades. Although coastal zone reclamation provides economic benefits, it produces a series of threats to coastal environments and ecosystems. Hence, the ecological costs and economic benefits of reclamation projects must be balanced. In this study, we select Tongzhou Bay, a key development area of the marine industry in the Jiangsu Province, as the research region to study the limits of reclamation control of the port operation area based on regional ecological security. First, we determine the standard limit values of the tidal catchment water line and the water dividing line, the change rate of the tidal flux ±5%, and water area of sandbars above the 0 m line based on key factors and evaluation indices for the ecological impact of reclamation in this region. Then, eight reclamation cases are investigated in Tongzhou Bay, which include the undeveloped natural state, development status, construction projects to be built, and possible construction scale based on the results of tidal current numerical simulation calculations. Although case 3 has impacts on Section 2 (DM2) tidal flux of less than 5% and on Section 1 (DM1) tidal flux of less than 10%, it causes a northward shift of the flood catchment water line in the middle of Yaosha. Finally, case 8 meets the requirements of the standard limit values of evaluation indicators, e.g., 1455 hectares of reclamation is the limit value to maintain the natural state of the Sanshahong channel and the stability of the tidal creek system and Yaosha. Therefore, the results suggest optimizing the structure and layout of breakwaters, controlling the restriction of reclamation, and further maintaining and protecting the ecological function of Tongzhou Bay.

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Tan, Li-Shan, Zhen-Ming Ge, Shi-Hua Li, Ya-Lei Li, Li-Na Xie e Jian-Wu Tang. "Reclamation-induced tidal restriction increases dissolved carbon and greenhouse gases diffusive fluxes in salt marsh creeks". Science of The Total Environment 773 (giugno 2021): 145684. http://dx.doi.org/10.1016/j.scitotenv.2021.145684.

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30

Alexander, Izakson, Sindawi Ahmad, Ben Shachar Inbar e Pikkel Joseph. "The Effect of Perioperative Fluid Management on Intraocular Pressure during Gynecologic Laparoscopic Pelvic Surgery". Journal of Ophthalmology 2018 (2018): 1–6. http://dx.doi.org/10.1155/2018/1457851.

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Abstract (sommario):

Purpose. Visual loss is a devastating perioperative complication that can result from elevated intraocular pressure (IOP). The Trendelenburg position during surgery increases IOP. The purpose of this study was to quantify IOP changes in patients undergoing laparoscopic hysterectomy, at different time points and body positions throughout the procedure, and to compare fluctuations of IOP during the perioperative period according to two fluid management protocols.Methods. Thirty women scheduled to undergo elective gynecologic laparoscopic pelvic surgery were randomly allocated to receive a liberal or restrictive fluid management protocol. IOP, mean arterial pressure, heart rate, exhaled tidal volume, end-tidal CO2, and ocular perfusion pressure were assessed prior, during, and postsurgery, at 8 time points altogether.Results. Mean changes in IOP were similar for the two protocols; the peak IOP was at the steep (peak) Trendelenburg position. For each protocol, IOP correlated positively with mean arterial pressure, and mean blood pressure correlated with ocular perfusion pressure.Conclusion. IOP was elevated during laparoscopic pelvic surgery and particularly at the steep Trendelenburg position. No differences were found in any of the parameters examined according to a liberal or restrictive fluid management protocol.

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Hureau, Thomas J., Joshua C. Weavil, Taylor S. Thurston, Hsuan-Yu Wan, Jayson R. Gifford, Jacob E. Jessop, Michael J. Buys, Russell S. Richardson e Markus Amann. "Pharmacological attenuation of group III/IV muscle afferents improves endurance performance when oxygen delivery to locomotor muscles is preserved". Journal of Applied Physiology 127, n. 5 (1 novembre 2019): 1257–66. http://dx.doi.org/10.1152/japplphysiol.00490.2019.

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Abstract (sommario):

We sought to investigate the role of group III/IV muscle afferents in limiting endurance exercise performance, independently of their role in optimizing locomotor muscle O2 delivery. While breathing 100% O2 to ensure a similar arterial O2 content ([Formula: see text]) in both trials, eight male cyclists performed 5-km time trials under control conditions (HCTRL) and with lumbar intrathecal fentanyl (HFENT) impairing neural feedback from the lower limbs. After each time trial, common femoral artery blood flow (FBF) was quantified (Doppler ultrasound) during constant-load cycling performed at the average power of the preceding time trial. The assessment of end-tidal gases, hemoglobin content and saturation, and FBF facilitated the calculation of leg O2 delivery. Locomotor muscle activation during cycling was estimated from vastus lateralis EMG. With electrical femoral nerve stimulation, peripheral and central fatigue were quantified by pre- to postexercise decreases in quadriceps twitch torque (ΔQtw) and voluntary activation (ΔVA), respectively. FBF (~16 mL·min−1·W−1; P = 0.6), [Formula: see text] (~24 mL O2/dL; P = 0.9), and leg O2 delivery (~0.38 mL O2·min−1·W−1; P = 0.9) were not different during HCTRL and HFENT. Mean power output and time to completion were significantly improved by 9% (~310 W vs. ~288 W) and 3% (~479 s vs. ~463 s), respectively, during HFENT compared with HCTRL. Quadriceps muscle activation was 9 ± 7% higher during HFENT compared with HCTRL ( P < 0.05). ΔQtw was significantly greater in HFENT compared with HCTRL (54 ± 8% vs. 39 ± 9%), whereas ΔVA was not different (~5%; P = 0.3) in both trials. These findings reveal that group III/IV muscle afferent feedback limits whole body endurance exercise performance and peripheral fatigue by restricting neural activation of locomotor muscle. NEW & NOTEWORTHY Group III/IV muscle afferent feedback facilitates endurance performance by optimizing locomotor muscle O2 delivery but also limits performance by restricting neural drive to locomotor muscle. To isolate the performance-limiting effect of these sensory neurons, we pharmacologically attenuated their central projection during a cycling time trial while controlling for locomotor muscle O2 delivery. With no difference in leg O2 delivery, afferent blockade attenuated the centrally mediated restriction in motoneuronal output and improved cycling performance.

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Yang, Hyunyoung, Jae Hyun Kim e Eun Ju Lee. "Impacts of tidal restriction caused by embankments on the plastic growth responses of Bolboschoenus planiculmis in Korea". Regional Studies in Marine Science 41 (gennaio 2021): 101616. http://dx.doi.org/10.1016/j.rsma.2021.101616.

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33

Addison, Anthony P., Paul S. Addison, Philip Smit, Dominique Jacquel e Ulf R. Borg. "Noncontact Respiratory Monitoring Using Depth Sensing Cameras: A Review of Current Literature". Sensors 21, n. 4 (6 febbraio 2021): 1135. http://dx.doi.org/10.3390/s21041135.

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Abstract (sommario):

There is considerable interest in the noncontact monitoring of patients as it allows for reduced restriction of patients, the avoidance of single-use consumables and less patient–clinician contact and hence the reduction of the spread of disease. A technology that has come to the fore for noncontact respiratory monitoring is that based on depth sensing camera systems. This has great potential for the monitoring of a range of respiratory information including the provision of a respiratory waveform, the calculation of respiratory rate and tidal volume (and hence minute volume). Respiratory patterns and apneas can also be observed in the signal. Here we review the ability of this method to provide accurate and clinically useful respiratory information.

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Kinnear, W., M. Petch, G. Taylor e J. Shneerson. "Assisted ventilation using cuirass respirators". European Respiratory Journal 1, n. 3 (1 marzo 1988): 198–203. http://dx.doi.org/10.1183/09031936.93.01030198.

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Abstract (sommario):

The effects of cuirass-assisted ventilation have been studied in 25 subjects with chest wall disease. Cuirass respirators increase ventilation in proportion to the peak negative pressure within the cuirass shell and the respiratory rate. Positive pressure applied during expiration produces little additional ventilation. During cuirass-assisted ventilation end-expiratory volume increases, arterial carbon dioxide tension (PaCO2) falls and arterial oxygen tension (PaO2) rises. Cardiac output is unchanged. Paradoxical chest wall motion is corrected by cuirass-assisted ventilation and restriction of chest wall expansion by the cuirass shell is minimal. Jacket-type respirators can produce larger tidal volumes than the cuirass at the same peak negative pressure, but are associated with greater air leakage.

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Ivanov, P. B., e J. C. B. Papaloizou. "On the evolution of a binary system with arbitrarily misaligned orbital and stellar angular momenta due to quasi-stationary tides". Monthly Notices of the Royal Astronomical Society 500, n. 3 (5 novembre 2020): 3335–67. http://dx.doi.org/10.1093/mnras/staa3409.

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Abstract (sommario):

ABSTRACT We consider the evolution of a binary system interacting due to tidal effects without restriction on the orientation of the orbital, and where significant, spin angular momenta, and orbital eccentricity. We work in the low tidal forcing frequency regime in the equilibrium tide approximation. Internal degrees of freedom are fully taken into account for one component, the primary. In the case of the companion the spin angular momentum is assumed small enough to be neglected but internal energy dissipation is allowed for as this can be significant for orbital circularization in the case of planetary companions. We obtain a set of equations governing the evolution of the orbit resulting from tidal effects. These depend on the masses and radii of the binary components, the form and orientation of the orbit, and for each involved component, the spin rate, the Coriolis force, the normalized rate of energy dissipation associated with the equilibrium tide due to radiative processes and viscosity, and the classical apsidal motion constant, k2. These depend on stellar parameters with no need of additional assumptions or a phenomenological approach as has been invoked in the past. They can be used to determine the evolution of systems with initial significant misalignment of spin and orbital angular momenta as hypothesized for systems containing Hot Jupiters. The inclusion of the Coriolis force may lead to evolution of the inclination between orbital and spin angular momenta and precession of the orbital plane which may have observational consequences.

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María Tirado Patiño e Daniel Paz Martín. "¿Cuál es el volumen tidal ideal en pacientes ingresados en UCI sin SDRA que requieren ventilación mecánica más de 24 horas?" Revista Electrónica AnestesiaR 11, n. 8 (2 settembre 2019): 3. http://dx.doi.org/10.30445/rear.v11i8.768.

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Abstract (sommario):

La protección pulmonar en los pacientes críticos sometidos a ventilación mecánica, es uno de los objetivos que persiguen los facultativos cuando utilizan esta herramienta terapéutica; que, pese a todos sus beneficios y su uso extendido, no está exenta de efectos adversos. El apoyo ventilatorio en el Síndrome de Distrés Respiratorio Agudo (SDRA) consta de una serie de medidas, entre las que se incluye el volumen tidal (VT) bajo. Pero, ¿qué ocurre con aquellos pacientes que precisan más de 24 horas de ventilación mecánica sin criterios de SDRA? ¿Cuál es su VT recomendado? La evidencia científica apoya que la ventilación con VT bajo se asocia a la disminución del número de complicaciones respiratorias en comparación con VT alto (si bien, los ensayos clínicos preexistentes comparaban volúmenes bajos de 6 ml/kg vs volúmenes muy altos, de más de 10 ml/kg) (1)(2). Por contra, los VT bajos pueden incrementar la necesidad de sedación, aumentan la tasa de asincronía entre el paciente y el ventilador e incluso algunos trabajos hablan de que podría aumentar el riesgo de delirio.(3) El objetivo principal del estudio fue determinar si una estrategia de ventilación con VT bajo es más efectiva que una estrategia de VT intermedio en función del número de días libres de ventilación en el día 28 en los pacientes vivos tras la aleatorización. ABSTRACT Which is the ideal tidal volume for patients in ICU without ARDS who need mechanical ventilation more than 24h? Invasive ventilation, one of the most frequently applied strategies in the intensive care unit (ICU), is increasingly recognized as a potentially harmful intervention. There is evidence that lung-protective ventilation using low tidal volumes improves survival in patients with acute respiratory distress syndrome (ARDS), but it is less certain whether tidal volume restriction benefits patients without ARDS. Two randomized clinical trials found tidal volume reduction to be associated with a lower number of pulmonary complications in patients without ARDS, and 2 individual patient data meta-analyses suggested that tidal volume reduction may shorten the time spent on the ventilator and duration of stay in the ICU and hospital. However, the use of low tidal volumes could lead to an in- creased need for sedation because of higher respiratory rate or patient-ventilator asynchrony and, possibly, self- inflicted lung injury due to compensatory injurious inspiratory efforts. In addition, it has been suggested that low tidal volumes may increase the risk of delirium. The Protective Ventilation in Patients Without ARDS (PReVENT) trial was conducted to test whether a ventilation strategy using low tidal volumes is superior to a ventilation strategy using intermediate tidal volumes with respect to the number of ventilator-free days and alive at day.

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Hernandez, L. A., K. J. Peevy, A. A. Moise e J. C. Parker. "Chest wall restriction limits high airway pressure-induced lung injury in young rabbits". Journal of Applied Physiology 66, n. 5 (1 maggio 1989): 2364–68. http://dx.doi.org/10.1152/jappl.1989.66.5.2364.

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Abstract (sommario):

High peak inspiratory pressures (PIP) during mechanical ventilation can induce lung injury. In the present study we compare the respective roles of high tidal volume with high PIP in intact immature rabbits to determine whether the increase in capillary permeability is the result of overdistension of the lung or direct pressure effects. New Zealand White rabbits were assigned to one of three protocols, which produced different degrees of inspiratory volume limitation: intact closed-chest animals (CC), closed-chest animals with a full-body plaster cast (C), and isolated excised lungs (IL). The intact animals were ventilated at 15, 30, or 45 cmH2O PIP for 1 h, and the lungs of the CC and C groups were placed in an isolated lung perfusion system. Microvascular permeability was evaluated using the capillary filtration coefficient (Kfc). Base-line Kfc for isolated lungs before ventilation was 0.33 +/- 0.31 ml.min-1.cmH2O-1.100g-1 and was not different from the Kfc in the CC group ventilated with 15 cmH2O PIP. Kfc increased by 850% after ventilation with only 15 cmH2O PIP in the unrestricted IL group, and in the CC group Kfc increased by 31% after 30 cmH2O PIP and 430% after 45 cmH2O PIP. Inspiratory volume limitation by the plaster cast in the C group prevented any significant increase in Kfc at the PIP values used. These data indicate that volume distension of the lung rather than high PIP per se produces microvascular damage in the immature rabbit lung.

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S, Lakshmikanthcharan, e MN Sivakumar. "Prone Ventilation in ARDS". Indian Journal of Respiratory Care 04, n. 02 (2 dicembre 2022): 624–31. http://dx.doi.org/10.5005/jp-journals-11010-04206.

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Abstract (sommario):

ARDS is a clinical syndrome characterised by severe refractory hypoxaemia associated with significant mortality and morbidity. Low tidal volume ventilation and restricting plateau pressure has got maximum survival benefit. Various others measures to tackle refractory hypoxaemia in patients with ARDS have been studied. Prone ventilation is one such rescue therapy which has shown promising results. This article is intended to discuss the benefits of prone ventilation and to clarify some of the common queries one has in practising prone ventilation.

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Rodríguez, Adrian, Sylvio Ferraz-Mello, Tatiana A. Michtchenko, Cristian Beaugé e Octavio Miloni. "Tidal evolution of a close-in planet with a more massive outer companion". Proceedings of the International Astronomical Union 6, S276 (ottobre 2010): 508–10. http://dx.doi.org/10.1017/s1743921311021004.

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Abstract (sommario):

AbstractWe investigate the motion of a two-planet coplanar system under the combined effects of mutual interaction and tidal dissipation. The secular behavior of the system is analyzed using two different approaches, restricting to the case of a more massive outer planet. First, we solve the exact equations of motion through the numerical simulation of the system evolution. We also compute the stationary solutions of the mean equations of motion based on a Hamiltonian formalism. An application to the real system CoRoT-7 is investigated.

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40

Waggitt, James J., Holly K. Dunn, Peter G. H. Evans, Jan Geert Hiddink, Laura J. Holmes, Emma Keen, Ben D. Murcott et al. "Regional-scale patterns in harbour porpoise occupancy of tidal stream environments". ICES Journal of Marine Science 75, n. 2 (31 agosto 2017): 701–10. http://dx.doi.org/10.1093/icesjms/fsx164.

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Abstract (sommario):

Abstract As harbour porpoises Phocoena phocoena are abundant within tidal stream environments, mitigating population-level impacts from tidal stream energy extraction is considered a conservation priority. An understanding of their spatial and temporal occupancy of these habitats at a regional-scale will help steer installations towards locations which maximize energy returns but reduce the potential for interactions with populations. This study quantifies and compares relationships between the presence of harbour porpoise and several hydrodynamic characteristics across four tidal stream environments in Anglesey, UK—a region that has been earmarked for extensive industrial development. Within sites (0.57–1.13 km2), encounters with animals were concentrated in small areas (<200 m2) and increased during certain tidal states (ebb vs. flood). In sites showing relatively high maximum current speeds (2.67–2.87 ms−1), encounters were strongly associated with the emergence of shear-lines. In sites with relatively low maximum current speeds (1.70–2.08 ms−1), encounters were more associated with areas of shallow water during peak current speeds. The overall probability of encounters was higher in low current sites. It is suggested that the likelihood of interactions could be reduced by restricting developments to sites with high maximum current speeds (>2.5 ms−1), and placing turbines in areas of laminar currents therein. This study shows that a combination of local and regional hydrodynamic characteristics can partially explain variations in occupancy patterns across tidal-stream environments. However, it was found that such hydrodynamic characteristics could not comprehensively explain these occupancy patterns. Further studies into the biophysical mechanisms creating foraging opportunities within these habitats are needed to identify alternative explanatory variables that may have universal applications.

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Hussain, S. N., B. Rabinovitch, P. T. Macklem e R. L. Pardy. "Effects of separate rib cage and abdominal restriction on exercise performance in normal humans". Journal of Applied Physiology 58, n. 6 (1 giugno 1985): 2020–26. http://dx.doi.org/10.1152/jappl.1985.58.6.2020.

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Abstract (sommario):

We assessed the effects of selective restriction of movements of the rib cage (Res,rc) and abdomen (Res,ab) on ventilatory pattern, transdiaphragmatic pressure (Pdi), and electrical activity of the diaphragm (Edi) in five normal subjects exercising at a constant work rate (80% of maximum power output) on a cycle ergometer till exhaustion. Restriction of movements was achieved by an inelastic corset applied tightly around the rib cage or abdomen. Edi was recorded by an esophageal electrode, rectified, and then integrated, and peak values during inspiration were measured. Each subject exercised at the same work rate on 3 days: with Res,rc, with Res,ab, and without restriction (control). Res,rc but not Res,ab reduced exercise time (tlim). Up to tlim, minute ventilation (VE) was similar in all three conditions. At any level of VE, however, Res,rc decreased tidal volume and inspiratory and expiratory time, whereas Res,ab had no effect on the pattern of breathing. Res,ab was associated with higher inspiratory Pdi swings at any level of VE, whereas peak Edi was similar to control. Inspiratory Pdi swings were the same with Res,rc as control, but the peak Edi for a given Pdi was greater with Res,rc (P less than 0.05). During Res,rc the abdominal pressure swings in expiration were greater than with Res,ab and control. We conclude that Res,rc altered the pattern of breathing in normal subjects in high-intensity exercise, decreased diaphragmatic contractility, increased abdominal muscle recruitment in expiration, and reduced tlim. On the other hand, Res,ab had no effect on breathing pattern or tlim but was associated with increased diaphragmatic contractility.

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O’Dell, Alexander, e Maria C. Babiuc Hamilton. "RisingTides: An Analytic Modeling Code of Tidal Effects in Binary Neutron Star Mergers". Astronomy 3, n. 3 (2 luglio 2024): 167–88. http://dx.doi.org/10.3390/astronomy3030011.

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Abstract (sommario):

Gravitational waves produced by binary neutron star mergers offer a unique window into matter behavior under extreme conditions. In this context, we analytically model the effect of matter on gravitational waves from binary neutron star mergers. We start with a binary black hole system, leveraging the post-Newtonian formalism for the inspiral and the Backwards-one-Body model for the merger. We combine the two methods to generate a baseline waveform and we validate our results against numerical relativity simulations. Next, we integrate tidal effects in phase and amplitude to account for matter and spacetime interaction using the NRTidal model and test its accuracy against numerical relativity predictions for two equations of state, finding a mismatch around the merger. Subsequently, we lift the restriction on the coefficients to be independent of the tidal deformability and recalibrate them using the numerical relativity predictions. We obtain better fits for phase and amplitude around the merger and are able to extend the phase modeling beyond the merger. We implement our method in new open-source, user-friendly Python code, steered by a Jupyter Notebook, named RisingTides. Our research offers new perspectives on analytically modeling the effect of tides on the gravitational waves from binary neutron star mergers.

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Wilding, Craig S., John Grahame e Peter J. Mill. "Nuclear DNA Restriction Site Polymorphisms and the Phylogeny and Population Structure of an Inter Tidal Snail Species Complex (Littorina)". Hereditas 133, n. 1 (ottobre 2000): 9–18. http://dx.doi.org/10.1111/j.1601-5223.2000.00009.x.

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44

Gonzalez-Montesinos, Jose L., Jorge R. Fernandez-Santos, Carmen Vaz-Pardal, Ruben Aragon-Martin, Aurelio Arnedillo-Muñoz, Jose Reina-Novo, Eva Orantes-Gonzalez, Jose Heredia-Jimenez e Jesus G. Ponce-Gonzalez. "Chronic Effects of a Training Program Using a Nasal Inspiratory Restriction Device on Elite Cyclists". International Journal of Environmental Research and Public Health 18, n. 2 (18 gennaio 2021): 777. http://dx.doi.org/10.3390/ijerph18020777.

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Abstract (sommario):

This study compared the response of a 9-week cycling training on ventilatory efficiency under two conditions: (i) Combined with respiratory muscle training (RMT) using a new nasal restriction device (FeelBreathe) (FB group) and (ii) without RMT (Control group). Eighteen healthy elite cyclists were randomly separated into the FB group (n = 10) or Control group (n = 8). Gas exchange was measured breath by breath to measure ventilatory efficiency during an incremental test on a cycloergometer before (Pre) and after (Post) the nine weeks of training. The FB group showed higher peak power (Δ (95%HDI) (0.82 W/kg (0.49, 1.17)), VO2max (5.27 mL/kg/min (0.69, 10.83)) and VT1 (29.3 W (1.8, 56.7)) compared to Control at PostFINAL. The FB group showed lower values from Pre to PostPRE in minute ventilation (VE) (−21.0 L/min (−29.7, −11.5)), Breathing frequency (BF) (−5.1 breaths/min (−9.4, −0.9)), carbon dioxide output (VCO2) (−0.5 L/min (−0.7, −0.2)), respiratory equivalents for oxygen (EqO2) (−0.8 L/min (−2.4, 0.8)), heart rate (HR) (−5.9 beats/min (−9.2, −2.5)), respiratory exchange ratio (RER) (−0.1 (−0.1, −0.0) and a higher value in inspiratory time (Tin) (0.05 s (0.00, 0.10)), expiratory time (Tex) (0.11 s (0.05, 0.17)) and end-tidal partial pressure of CO2 (PETCO2) (0.3 mmHg (0.1, 0.6)). In conclusion, RMT using FB seems to be a new and easy alternative ergogenic tool which can be used at the same time as day-to-day training for performance enhancement.

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Williams, David T. "Against the Tide: Christian Self-limitation". Evangelical Quarterly: An International Review of Bible and Theology 70, n. 3 (12 settembre 1998): 247–60. http://dx.doi.org/10.1163/27725472-07003004.

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Abstract (sommario):

The desire for continual growth and expansion is an almost unquestioned part of the modern Western world-view, expressed in technological progress and particularly in economic policy. Such an attitude must be questioned by Christianity in the light of God who limited himself in creation and of the limitation of Christ in incarnation and redemption. Such self-limitation was done from a desire for relationship with the world and in particular with the redeemed. In imitation of this, the Christian attitude should also be of self-limitation, both on a personal level and also on a social level, manifested in attitudes of restricted use of resources and of restriction in population growth.

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LeMaster, William, Dale Jun, Sharon De Cruz, Michelle Zeidler e Rajan Saggar. "824 Case Series on the Use of Volume Assured Pressure Support in Patients with Chronic Pulmonary Disease and Progressive Hypercapnia". Sleep 44, Supplement_2 (1 maggio 2021): A321—A322. http://dx.doi.org/10.1093/sleep/zsab072.821.

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Abstract (sommario):

Abstract Introduction Chronic hypercapnia results from destruction of lung parenchyma which occurs in chronic lung diseases including interstitial lung disease (ILD), bronchiectasis, and chronic lung transplant rejection. Many patients with these diseases will experience progressive respiratory failure eventually requiring consideration of transplantation or re-transplantation. Due to physiologic changes in sleep including reduction in tidal volume, worsening air tapping, and REM atonia, hypoventilation can be exacerbated during the sleeping hours. We present four patients who were prescribed nocturnal Volume Assured Pressure Support VAPS for their progressive hypercapnia. Report of case(s) Subject 1 is a 72 year old female with severe bronchiectasis and restrictive lung disease due to TB pneumonia at a young age. Subject 2 is a 45 year old male with history of pulmonary cavitation due to extensive TB disease when he was younger. Subject 3 is a 45-year-old woman with rheumatoid arthritis related ILD with associated pulmonary arterial hypertension. Subject 4 is a 74 year old patient with a bilateral lung transplant for IPF complicated by bronchiolitis obliterans syndrome who presented with progressive dyspnea and hypercapnia. Despite optimal therapy, all of these patients were admitted for hypercapnic and hypoxemic respiratory failure requiring treatment with BPAP then transitioned to nocturnal VAPS on discharge. For all patients, dyspnea and pCO2 improved as outpatients although all patients did eventually experience an exacerbation of their lung disease requiring repeat admission. Conclusion Due to the physiologic changes that occur with sleep, patients with severe lung disease may experience worsening CO2 retention while sleeping. There is little data assessing the use of chronic nocturnal non-invasive ventilation (NIV) to treat the hypercapnia of chronic lung diseases other than chronic obstructive pulmonary disease, extra-thoracic restriction, and neuromuscular disease. In this case series, nocturnal VAPS stabilized and/or reduced pCO2 in patients with pulmonary parenchymal disease of various etiologies. Additional studies are needed to assess long term effects of VAPS in these patients, including exacerbations, symptoms, and overall mortality. Support (if any):

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Hackett, Daniel A., Boliang Wang e Derek L. Tran. "Effect of Blood Flow Restriction during the Rest Periods of Squats on Accuracy of Estimated Repetitions to Failure". Sports 12, n. 1 (31 dicembre 2023): 14. http://dx.doi.org/10.3390/sports12010014.

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Abstract (sommario):

This study investigated the impact of resistance training with blood flow restriction during rest (BFRrest) on the accuracy of estimated repetitions to failure (ERF). It also explored associations between error in ERF and mean concentric velocity (MCV) along with physiological responses. In a randomised cross-over study, 18 male trainers (23.4 ± 2.7 years) performed three sets of squats at 70% of their one-repetition maximum until failure. One session integrated BFRrest, while another employed traditional passive inter-set rest (TRAD) during the 3 min inter-set rest intervals. Cardiorespiratory and metabolic measures were taken in the inter-set recovery periods. The results revealed no significant differences between BFRrest and TRAD in terms of ERF and error in ERF. A notable set effect for ERF was observed, with a greater ERF during set 1 compared to sets 2 and 3 (p < 0.001). Additionally, a lower error in ERF was observed during sets 2 and 3 compared to set 1 (p < 0.001). Error in ERF were strongly associated with the respiratory exchange ratio, and moderately associated with end-tidal carbon dioxide partial pressure, carbon dioxide output, and MCV variables. Notably, the precision of ERF seems to be predominantly influenced by indicators of physiological stress rather than the incorporation of BFRrest.

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Wootton, David M., Haiyan Luo, Steven C. Persak, Sanghun Sin, Joseph M. McDonough, Carmen R. Isasi e Raanan Arens. "Computational fluid dynamics endpoints to characterize obstructive sleep apnea syndrome in children". Journal of Applied Physiology 116, n. 1 (1 gennaio 2014): 104–12. http://dx.doi.org/10.1152/japplphysiol.00746.2013.

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Abstract (sommario):

Computational fluid dynamics (CFD) analysis may quantify the severity of anatomical airway restriction in obstructive sleep apnea syndrome (OSAS) better than anatomical measurements alone. However, optimal CFD model endpoints to characterize or assess OSAS have not been determined. To model upper airway fluid dynamics using CFD and investigate the strength of correlation between various CFD endpoints, anatomical endpoints, and OSAS severity, in obese children with OSAS and controls. CFD models derived from magnetic resonance images were solved at subject-specific peak tidal inspiratory flow; pressure at the choanae was set by nasal resistance. Model endpoints included airway wall minimum pressure (Pmin), flow resistance in the pharynx (Rpharynx), and pressure drop from choanae to a minimum cross section where tonsils and adenoids constrict the pharynx ( dP TAmax). Significance of endpoints was analyzed using paired comparisons ( t-test or Wilcoxon signed rank test) and Spearman correlation. Fifteen subject pairs were analyzed. Rpharynx and dP TAmax were higher in OSAS than control and most significantly correlated to obstructive apnea-hypopnea index (oAHI), r = 0.48 and r = 0.49, respectively ( P < 0.01). Airway minimum cross-sectional correlation to oAHI was weaker ( r = −0.39); Pmin was not significantly correlated. CFD model endpoints based on pressure drops in the pharynx were more closely associated with the presence and severity of OSAS than pressures including nasal resistance, or anatomical endpoints. This study supports the usefulness of CFD to characterize anatomical restriction of the pharynx and as an additional tool to evaluate subjects with OSAS.

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Creane, Shauna, Michael O’Shea, Mark Coughlan e Jimmy Murphy. "Morphological Modelling to Investigate the Role of External Sediment Sources and Wind and Wave-Induced Flow on Sand Bank Sustainability: An Arklow Bank Case Study". Journal of Marine Science and Engineering 11, n. 10 (22 ottobre 2023): 2027. http://dx.doi.org/10.3390/jmse11102027.

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Offshore anthropogenic activities such as the installation of Offshore Renewable Energy (ORE) developments and sediment extraction for marine aggregates have been shown to disrupt current flow, wave propagation, and sediment transport pathways, leading to potential environmental instability. Due to the complexity of the interconnected sediment transport pathways in the south-western Irish Sea combined with an increase in planned anthropogenic activities, the assessment of this risk is imperative for the development of a robust marine spatial plan. Subsequently, this study uses two-dimensional morphological modelling to build upon previous studies to assess the dependency of Arklow Bank’s local sediment transport regime on external sediment sources. Additionally, scenario modelling is used to identify vulnerable areas of this offshore linear sand bank to wind and wave-forcing and to examine the nature of this impact. A sediment budget is estimated for Arklow Bank, whereby seven source and nine sink pathways are identified. New evidence to support the exchange of sediment between offshore sand banks and offshore independent sand wave fields is also provided. The areas of the bank most vulnerable to changes in external sediment sources and the addition of wind- and wave-induced flow are analogous. These high vulnerability zones (HVZs) align with regions of residual cross-flow under pure current conditions. The restriction of sediment sources off the southern extent of Arklow Bank impacts erosion and accretion patterns in the mid- and northern sections of the bank after just one lunar month of simulation. Where tidal current is the primary driver of sand bank morphodynamics, wind- and wave-induced flow is shown to temporarily alter sediment distribution patterns. Wind and wave-induced flow can both accelerate and decelerate the east-west fluctuation of the upper slopes of the bank, yet the nature of this impact is inconsistent due to the misalignment of the directionality of these two forces. The methods and new knowledge derived from this study are directly applicable to tidally-dominated environments outside the Irish Sea.

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50

Wirana, Andjar Pachta. "LARANGAN PRAKTEK MONOPOLI DAN PERSAlNGAN USAHA TIDAK SEHAT PENGECUALIAN-TERHADAP BADAN USAHA KOPERASI". Jurnal Hukum & Pembangunan 39, n. 1 (3 marzo 2009): 74. http://dx.doi.org/10.21143/jhp.vol39.no1.198.

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AbstrakThis article elaborates two law discourses regarding cooperative (koperasi)status and anti monopoly restriction. Under the Constitution of the RepublicIndonesia the cooperative as people business lInit is facilitated by economicpolicy. The policy has been aimed to delivery wider portion througheconomic system which closes to people. It has been known as peopleeconomic system with motlo wider spread and national democratic economy.The author concedes to giving any exclusion to cooperative disregardstoward anti monopoly law. Exclusion itself is explicitly reflected any legalprotection from the State to people economic. It protection by shields andgives opportunity for cooperatives and small business units to develop andbecomes strong in their business proportionally.

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