76 research outputs found
Branching ratio of the H (n=2) shape resonance
[[abstract]]The relative photodetachment cross section for decay into the H(N=2) channel by the 1P° shape resonance in H- was measured, as well as that for decay into all channels. The branching ratio σ(N=2)/σ(total) was computed for a series of energies between 10.95 and 11.3 eV after normalizing the cross sections to theoretical peak amplitudes. The maximum branching ratio (≊0.8) appears at an energy about 20 meV higher than the central energy of the resonance. Results are compared with recent theoretical calculations.[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]US
Electric-field effects on H- photodetachment partial cross sections above 13.4 eV
[[abstract]]When static electric fields (F≤90 kV/cm) were applied to the H- photodetachment interaction region, new structure and lowered thresholds for production of neutral hydrogen were observed. Relative partial cross sections were measured by detection of excited states of the fragment neutral hydrogen atom H(N=4, 5, or 6) resulting from laser interaction with relativistic H- ions. Downward shifts in the onset of excited hydrogen production are observed to increase with field strength, and agree with a recent hyperspherical coordinate interpretation of Zhou and Lin [Phys. Rev. Lett. 69, 3294 (1992)]. Field-induced window-type resonance structure is observed both below and above the zero-field threshold (ZFT) energy. Quenching of high-lying autoionizing states was also monitored, providing evidence of field-induced tunneling by resonances lying just below the associated ZFT.[[incitationindex]]SCI[[booktype]]紙
Central Atlantic Coastal Plain - A Summary of the Geological Evolution of Chesapeake Bay, Eastern United States
The seaward margin of the U.S. Atlantic Coastal Plain has fluctuated through time, from near the Fall Line to near the edge of the present Outer Continental Shelf, owing to changes in relative sea level. The strata that underlie the Coastal Plain were deposited in environments that ranged from fully terrestrial to fully marine. Estuarine environments are critical components of the Coastal Plain; they represent the interface, otherwise known as the shoreline, between the marine and terrestrial depositional systems. The Quaternary evolution of estuaries has important implications for both documenting the history of sea-level changes and interpreting ancient coastal-plain strata. In this paper, we briefly summarize the Quaternary history of the Chesapeake Bay, the largest of the many Coastal Plain estuaries on the Atlantic coast. This summary is based on recent syntheses of a wide variety of data (Colman and others, 1988, 1990; Colman and Mixon, 1988) on the history and evolution of the bay.https://scholarworks.wm.edu/vimsbooks/1114/thumbnail.jp
Quaternary Geology of the Chesapeake Bay
The Chesapeake Bay, which is a classic coastal plain estuary, is located on a trailing edge continental margin. It has a surface area of nearly 6,000 km2 and ranges in width from 8 to 48 km. The morphology of the bay clearly reflects its formation as a response to fluctuating sea level during and following the last major continental glaciation. The shoreline is highly irregular, the tributaries form an intricate dendritic drainage pattern, and a deep axial channel occurs along much of its length (fig. 1). Water depths commonly exceed 30m in this deep channel, which is flanked by broad shallow benches. Overall, the bay is quite shallow and has an average depth _of only 8 m. more....https://scholarworks.wm.edu/vimsbooks/1115/thumbnail.jp
Ancient channels of the Susquehanna River beneath Chesapeake Bay and the Delmarva Peninsula
Three generations of the ancestral Susquehanna River system have been mapped beneath Chesapeake Bay and the southern Delmarva Peninsula. Closely spaced seismic reflection profiles in the bay and boreholes in the bay and on the southern Delmarva Peninsula allow detailed reconstruction of each paleochannel system. The channel systems were formed during glacial low sea-level stands, and each contains a channel-fill sequence that records the subsequent transgression. The trunk channels of each system are 2 to 4 km wide and are incised 30 to SO m into underlying strata; they have irregular longitudinal profiles and very low gradients within the Chesapeake Bay area
Expression of Growth Factors and Growth Factor Receptor in Non-healing and Healing Ischaemic Ulceration
AbstractObjectivesTo characterise the histological and cytokinetic characteristics of purely ischaemic ulcers and the processes that underpin healing following successful revascularisation.DesignProspective observational study.Materials and methodsBiopsies were taken immediately pre- and 6 weeks following successful revascularisation of solely ischaemic ulceration. They were evaluated for morphological differences using H&E staining for the platelet derived growth factor receptor (PDGFR), epidermal growth factor receptor (EGFR), TGFβreceptorIII (TGFβRIII), transforming growth factor beta 1 and 3 (TGFβ1 and TGFβ3) and von Willebrand factor (vWF) expression using immunohistochemistry. Localisation and quantification of these growth factors and receptors was assessed systematically by three independent investigators who were blinded to the timing of biopsy.ResultsPre-operatively, small vessel vasculitis, necrosis and infection with a profuse neutrophil and macrophage infiltrate was observed in all samples. Post-operative biopsies revealed a proliferation of new capillaries in and around the ulcer edge and base. vWF staining confirmed an endothelial layer within these new vessels. Following successful revascularisation there was less infection and inflammation with minimal vasculitis. These newly formed capillaries had increased staining for TGFβ3, PDGFR and TGFβRIII with staining for PDGFR also localised to dermal fibroblasts which were larger and more numerous. Accelerated epithelial cell proliferation was observed with detachment from the underlying dermis.ConclusionsHealing of purely ischaemic ulcers is characterised by vasculogenesis associated with increased presence of the proangiogenic cytokines PDGF and TGFβ3. These findings show promise for the use of growth factor manipulation to aid healing in ischaemic ulcers
Сучасний стан бджільництва в Україні та перспективи розвитку апі-туризму в Рівненській області
The article examines the current state and problems of beekeeping products market development in the Rivne region and Ukraine. The prospects for the development of apiturism in the Rivne region have been assessed. It has been established that Ukraine has sufficient resources for the intensification of the development of tourist and recreational activities, the use of which will contribute to the development of infrastructure and the solution of a number of social and economic issues of the activities of territorial communities, the development of environmental education, the dissemination of knowledge about the history and culture of our people, and the improvement of the population. Apitourism, as a component of rural green tourism of the Rivne region, will contribute to the preservation of jobs in rural areas and is a way to ensure the development of the infrastructure of non-urbanized rural areas with minimal technogenic load. The further development of apitourism will contribute to the growth of a positive image of Ukraine in the international arena as a producer and exporter of high-quality beekeeping products. The territory of the Rivne region is sufficiently equipped with natural objects for the development of beekeeping and apitourism in particular. In the presence of significant areas of the objects of the nature reserve fund, the territory of which is not subject to significant anthropogenic load, it is possible to increase the production of beekeeping products from ecologically clean territories and the implementation of state and regional programs for the development of this type of activity. On the example of one of the personal peasant households, it was established that the apitherapy of the private estate of Malih Sadiv is a young direction of modern medicine in the Rivne region. It consists in the use of healing products produced by bees. They are used to improve the health of the human body to strengthen immunity. The air inside the api-inhalation room is saturated with biologically active substances of propolis, which has antimicrobial properties.У статті розглянуто сучасний стан та проблеми розвитку ринку продукції бджільництва в Рівненській області та Україні. Оцінено перспективи розвитку апітуризму в Рівненській області. Встановлено, що Україна володіє достатніми для інтенсифікації розвитку туристично-рекреаційної діяльності ресурсами, використання яких сприятиме розвитку інфраструктури та вирішенню ряду соціальних та економічних питань діяльності територіальних громад, розвитку екологічної освіти, поширенню знань про історію та культуру нашого народу, оздоровлення населення. Апітуризм як складова сільського зеленого туризму Рівненщини, сприятиме збереженню робочих місць в сільській місцевості та є способом забезпечення розвитку інфраструктури неурбанізованих сільських територій при мінімальному техногенному навантаженні. Подальший розвиток апітуризму сприятиме зростанню позитивного іміджу України на міжнародній арені, як виробника і експортера якісної продукції бджільництва. Територія Рівненської області достатньо забезпечена природними об’єктами для розвитку бджільництва та апітуризму зокрема. За наявності значних площ об’єктів природно-заповідного фонду, територія яких не зазнає значного антропогенного навантаження, можливе збільшення обсягів виробництва продукції бджільництва з екологічно чистих територій та впровадження державних і регіональних програм розвитку даного виду діяльності. На прикладі одного з особистих селянських господарств встановлено, що апітерапія приватної садиби с. Малих Садів є молодим напрямком сучасної медицини Рівненської області. Вона полягає у використанні цілющих продуктів, вироблених бджолами. Їх застосовують для оздоровлення організму людини та зміцнення імунітету. Повітря апі-інгаляційної кімнати всередині насичене біологічно активними речовинами прополісу, який має антимікробні властивості
Rapid sea level rise and ice sheet response to 8,200-year climate event
Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 34 (2007): L20603, doi:10.1029/2007GL031318.The largest abrupt climatic reversal of the Holocene interglacial, the cooling event 8.6–8.2 thousand years ago (ka), was probably caused by catastrophic release of glacial Lake Agassiz-Ojibway, which slowed Atlantic meridional overturning circulation (AMOC) and cooled global climate. Geophysical surveys and sediment cores from Chesapeake Bay reveal the pattern of sea level rise during this event. Sea level rose ~14 m between 9.5 to 7.5 ka, a pattern consistent with coral records and the ICE-5G glacio-isostatic adjustment model. There were two distinct periods at ~8.9–8.8 and ~8.2–7.6 ka when Chesapeake marshes were drown as sea level rose rapidly at least ~12 mm yr−1. The latter event occurred after the 8.6–8.2 ka cooling event, coincided with extreme warming and vigorous AMOC centered on 7.9 ka, and may have been due to Antarctic Ice Sheet decay.Cronin, Willard, Thunell, Berke
supported by USGS Earth Surface Dynamics Program; Vogt and Pohlman
by Office of Naval Research; Halka by MGS
Impact of renal impairment on atrial fibrillation: ESC-EHRA EORP-AF Long-Term General Registry
Background: Atrial fibrillation (AF) and renal impairment share a bidirectional relationship with important pathophysiological interactions. We evaluated the impact of renal impairment in a contemporary cohort of patients with AF. Methods: We utilised the ESC-EHRA EORP-AF Long-Term General Registry. Outcomes were analysed according to renal function by CKD-EPI equation. The primary endpoint was a composite of thromboembolism, major bleeding, acute coronary syndrome and all-cause death. Secondary endpoints were each of these separately including ischaemic stroke, haemorrhagic event, intracranial haemorrhage, cardiovascular death and hospital admission. Results: A total of 9306 patients were included. The distribution of patients with no, mild, moderate and severe renal impairment at baseline were 16.9%, 49.3%, 30% and 3.8%, respectively. AF patients with impaired renal function were older, more likely to be females, had worse cardiac imaging parameters and multiple comorbidities. Among patients with an indication for anticoagulation, prescription of these agents was reduced in those with severe renal impairment, p <.001. Over 24 months, impaired renal function was associated with significantly greater incidence of the primary composite outcome and all secondary outcomes. Multivariable Cox regression analysis demonstrated an inverse relationship between eGFR and the primary outcome (HR 1.07 [95% CI, 1.01–1.14] per 10 ml/min/1.73 m2 decrease), that was most notable in patients with eGFR <30 ml/min/1.73 m2 (HR 2.21 [95% CI, 1.23–3.99] compared to eGFR ≥90 ml/min/1.73 m2). Conclusion: A significant proportion of patients with AF suffer from concomitant renal impairment which impacts their overall management. Furthermore, renal impairment is an independent predictor of major adverse events including thromboembolism, major bleeding, acute coronary syndrome and all-cause death in patients with AF
Clinical complexity and impact of the ABC (Atrial fibrillation Better Care) pathway in patients with atrial fibrillation: a report from the ESC-EHRA EURObservational Research Programme in AF General Long-Term Registry
Background: Clinical complexity is increasingly prevalent among patients with atrial fibrillation (AF). The ‘Atrial fibrillation Better Care’ (ABC) pathway approach has been proposed to streamline a more holistic and integrated approach to AF care; however, there are limited data on its usefulness among clinically complex patients. We aim to determine the impact of ABC pathway in a contemporary cohort of clinically complex AF patients. Methods: From the ESC-EHRA EORP-AF General Long-Term Registry, we analysed clinically complex AF patients, defined as the presence of frailty, multimorbidity and/or polypharmacy. A K-medoids cluster analysis was performed to identify different groups of clinical complexity. The impact of an ABC-adherent approach on major outcomes was analysed through Cox-regression analyses and delay of event (DoE) analyses. Results: Among 9966 AF patients included, 8289 (83.1%) were clinically complex. Adherence to the ABC pathway in the clinically complex group reduced the risk of all-cause death (adjusted HR [aHR]: 0.72, 95%CI 0.58–0.91), major adverse cardiovascular events (MACEs; aHR: 0.68, 95%CI 0.52–0.87) and composite outcome (aHR: 0.70, 95%CI: 0.58–0.85). Adherence to the ABC pathway was associated with a significant reduction in the risk of death (aHR: 0.74, 95%CI 0.56–0.98) and composite outcome (aHR: 0.76, 95%CI 0.60–0.96) also in the high-complexity cluster; similar trends were observed for MACEs. In DoE analyses, an ABC-adherent approach resulted in significant gains in event-free survival for all the outcomes investigated in clinically complex patients. Based on absolute risk reduction at 1 year of follow-up, the number needed to treat for ABC pathway adherence was 24 for all-cause death, 31 for MACEs and 20 for the composite outcome. Conclusions: An ABC-adherent approach reduces the risk of major outcomes in clinically complex AF patients. Ensuring adherence to the ABC pathway is essential to improve clinical outcomes among clinically complex AF patients
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