946 research outputs found
Comparison of terrestrial and airborne LiDAR in describing stand structure of a thinned lodgepole pine forest
No full textAirborne LiDAR (ALS) has been widely used for measuring canopy structure, but much of the woody components of the canopy are not directly visible with this system. Terrestrial LiDAR (TLS) data may help fill this gap by helping to understand the relationship between above- and below-canopy architecture. In this study, we report on the potential for combining TLS and ALS, thereby focusing on forest inventory and wood quality?related characteristics (such as number and dimension of branches). Our results show that both TLS and ALS were able to describe stand height using the top 10% of LiDAR returns at a high level of precision; however, TLS measurements were negatively biased by approximately 1 m (R 2 = 0.96 and 0.86 for ALS and TLS, respectively; P < 0.05). The distribution of foliage measured by ALS and TLS was strongly related to basal area (R 2 = 0.63 and 0.91 for ALS and TLS, respectively) and stand density (R 2 = 0.89 and 0.72 for ALS and TLS, respectively). Tree-level attributes were more accurately described by TLS (R 2 = 0.63) compared with ALS (R 2 = 0.37) for crown depth and a similar result applied to dbh with R 2 = 0.63 for TLS versus R 2 = 0.43 for ALS
Detektion und akustikophysikalische Analyse von mikroembolischen Signalen mittels transkranieller Zweikanal-Dopplersonographie bei terminal herzinsuffizienten Patienten:mit pulsatilem linksventrikulären Unterstützungssystem und deren Korrelation zu klinischen und hämostaseologischen Parametern
No full textAnzahl und signalmorphologische Eigenschaften von MES wurden bei 15 Patienten mit LVAD (Novacor N 100® oder TCI HeartMate®) mittels serieller TCD detektiert und beide LVAD hinsichtlich MES-Rate und -Morphologie in Korrelation mit effektiver Antikoagulation und thrombembolischen Komplikationen verglichen. Während der kumulativen Unterstützungszeit von 3499 Tagen traten 12 Thrombembolien bei 5 der 9 Novacor®- und 9 Thrombembolien bei 3 der 6 TCI HeartMate®-Patienten auf (p = 0,95). Die MES-Prävalenz zeigte zum Auftreten von thrombembolischen Insulten und zum Anteil effektiv antikoagulierter Tage im Gesamt- (r = 0,37), TCI HeartMate®- (r = 0,27) Novacor®-Kollektiv (r = 0,47) keine signifikante Korrelation. Der MES-Mittelwert korrelierte beim Gesamt- und TCI HeartMate®-Kollektiv (r = 0,54; p = 0,04 und r = 0,88; p = 0,03) signifikant mit der Insultanzahl. In dem Novacor®-Kollektiv ist signalmorphologisch ein größerer Anteil an soliden Mikroembolien anzunehmen als im TCI Heartmate®-Kollektiv (p-Wert <0,0001)
Automated reconstruction of tree and canopy structure for modeling the internal canopy radiation regime
No full textUnderstanding canopy radiation regimes is critical to successfully modeling vegetation growth and function. For instance, the vertical distribution of photosynthetically active radiation (PAR) affects vegetation growth, informative upon carbon and energy cycling. Availing upon advances in information capture and computing power, geometrically explicit modeling of forest structure becomes increasingly possible. A primary challenge however is acquiring the forest mensuration data required to parameterize these models and the related automation of modeling forest structure. In this research, to address these issues we employ a novel and automated approach that capitalizes upon the rich information afforded by ground-based laser scanning technology. The method is implemented in two steps: in the first step, geometric explicit models of canopy structure are created from the ground-based laser scanning data. These geometric explicit models are used to simulate the vertical range to first hit. In the second step, we derive canopy gap probability from full waveform laser scanning data which have been used in a number of studies for characterization of radiation transmission (Jupp et al., 2009; Yang et al., 2010) and do not require any geometric explicit modeling. The radiative consistency of the geometric explicit models from step 1 is validated against the gap probabilities of step 2. The results show a strong relationship between the radiative transmission properties of the geometric models and canopy gap probabilities at plot level (R = 0.91 to 0.97), while the geometric models suggest the additional benefit to serve as a bridge in scaling between shoot level and canopy level radiation
Improved detection of silent atrial fibrillation using 72-hour Holter ECG in patients with ischemic stroke:a prospective multicenter cohort study
No full textBACKGROUND AND PURPOSE: Adequate diagnosis of atrial fibrillation (AF), including paroxysmal AF, is an important part of stroke workup. Prolonged ECG monitoring may improve the detection of paroxysmal, previously undiagnosed AF (unknown AF). Therefore, we evaluated systematic 72-hour Holter ECG monitoring to detect unknown AF for the workup of patients with stroke.METHODS: Unselected survivors of a stroke or transient ischemic attack (TIA) without known AF were enrolled in a prospective, multicenter cohort study of 72-hour Holter ECG monitoring in 9 German secondary and tertiary stroke centers between May 2010 and January 2011. In addition to standardized workup of stroke pathogenesis according to the German Stroke Unit protocol, all patients underwent 72-hour Holter ECG monitoring directly after admission. All ECGs were centrally analyzed by 2 independent observers. We determined the proportion of unknown AF and compared the detection rates of 72- and 24-hour monitoring.RESULTS: A total of 1135 patients were enrolled (mean age, 67 years [SD, 13.1 years], 45% women, 29% TIA). Unknown AF was detected in 49 out of 1135 patients (4.3%, [95% confidence interval, 3.4-5.2%]) by 72-hour ECG monitoring. Unknown AF was diagnosed in 29 patients (2.6%) within the first 24 hours of ECG monitoring, and in 20 more patients only by 72 hours of ECG monitoring. The number needed to screen by 72-hour ECG was 55 patients (95% confidence interval [35-123]) for each additional AF diagnosis. Patients with unknown AF were significantly older and had more often a history of previous stroke. Patients with unknown AF were equally distributed within categories of pathogenesis according to Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification.CONCLUSIONS: In unselected survivors of stroke or TIA, 72-hour ECG monitoring is feasible and improves the detection rate of silent paroxysmal AF.</p
Detektion und akustikophysikalische Analyse von mikroembolischen Signalen mittels transkranieller Zweikanal-Dopplersonographie bei terminal herzinsuffizienten Patienten:mit pulsatilem linksventrikulären Unterstützungssystem und deren Korrelation zu klinischen und hämostaseologischen Parametern
No full textAnzahl und signalmorphologische Eigenschaften von MES wurden bei 15 Patienten mit LVAD (Novacor N 100® oder TCI HeartMate®) mittels serieller TCD detektiert und beide LVAD hinsichtlich MES-Rate und -Morphologie in Korrelation mit effektiver Antikoagulation und thrombembolischen Komplikationen verglichen. Während der kumulativen Unterstützungszeit von 3499 Tagen traten 12 Thrombembolien bei 5 der 9 Novacor®- und 9 Thrombembolien bei 3 der 6 TCI HeartMate®-Patienten auf (p = 0,95). Die MES-Prävalenz zeigte zum Auftreten von thrombembolischen Insulten und zum Anteil effektiv antikoagulierter Tage im Gesamt- (r = 0,37), TCI HeartMate®- (r = 0,27) Novacor®-Kollektiv (r = 0,47) keine signifikante Korrelation. Der MES-Mittelwert korrelierte beim Gesamt- und TCI HeartMate®-Kollektiv (r = 0,54; p = 0,04 und r = 0,88; p = 0,03) signifikant mit der Insultanzahl. In dem Novacor®-Kollektiv ist signalmorphologisch ein größerer Anteil an soliden Mikroembolien anzunehmen als im TCI Heartmate®-Kollektiv (p-Wert <0,0001)
Prediction of wood fiber attributes from LiDAR-derived forest canopy indicators
No full textWe investigated the potential use of airborne light detection and ranging (LiDAR) data to predict key wood fiber properties from extrinsic indicators in lodgepole pine leading forest stands located in the foothills of central Alberta, Canada. Six wood fiber attributes (wood density, cell perimeter, cell coarseness, mature fiber length, microfibril angle, and modulus of elasticity) were measured at 21 plots, and with use of data reduction techniques, two components of wood properties were derived: wood strength, stiffness, and fiber yield and fiber strength and smoothness. These wood fiber components were then compared with extrinsic indicators of wood characteristic-derived LiDAR-estimated topographic morphology, tree height, and canopy light metrics. The first principal component indicating wood strength and stiffness was significantly correlated to the depth of different canopy zones (or light regimes; r 2 = 0.55, P < 0.05). The second component, related to fiber strength and smoothness, was significantly correlated to the height of the canopy and canopy thickness (r 2 = 0.65, P < 0.05). The results indicate that airborne LiDAR attributes can explain about half of the observed variance in intrinsic wood fiber attributes, which is approximately 5?10% less than that explained by growth-related field-measured variables such as diameter increment and height. This reduction in explained variance can be balanced by the opportunities for much broader spatial characterizations of wood quantity and quality at the stand and landscape levels
Comparing canopy metrics derived from terrestrial and airborne laser scanning in a Douglas-fir dominated forest stand
No full textAccurate estimates of vegetation structure are important for a large number of applications including ecological modeling and carbon budgets. Light detection and ranging (LiDAR) measures the three-dimensional structure of vegetation using laser beams. Most LiDAR applications today rely on airborne platforms for data acquisitions, which typically record between 1 and 5 “discrete” returns for each outgoing laser pulse. Although airborne LiDAR allows sampling of canopy characteristics at stand and landscape level scales, this method is largely insensitive to below canopy biomass, such as understorey and trunk volumes, as these elements are often occluded by the upper parts of the crown, especially in denser canopies. As a supplement to airborne laser scanning (ALS), a number of recent studies used terrestrial laser scanning (TLS) for the biomass estimation in spatially confined areas. One such instrument is the Echidna® Validation Instrument (EVI), which is configured to fully digitize the returned energy of an emitted laser pulse to establish a complete profile of the observed vegetation elements. In this study we assess and compare a number of canopy metrics derived from airborne and TLS. Three different experiments were conducted using discrete return ALS data and discrete and full waveform observations derived from the EVI. Although considerable differences were found in the return distribution of both systems, ALS and TLS were both able to accurately determine canopy height (? height < 2.5 m) and the vertical distribution of foliage and leaf area (0.86 > r 2 > 0.90, p < 0.01). When using more spatially explicit approaches for modeling the biomass and volume throughout the stands, the differences between ALS and TLS observations were more distinct; however, predictable patterns exist based on sensor position and configuration
The Book of Daniel and manticism: a critical assessment of the view that the Book of Daniel derives from a mantic tradition
No full textThis dissertation examines the consensus view that is based on Hans-Peter
Müller's 1969 and 1972 articles: Daniel was a mantic wise man in the Mesopotamian
ASA
court, and this was the self-understanding or aspiration of the maskilim of Dan 11:33, 35,
12:3, 10, who wrote the book. Chapter 1 reviews the arguments that make the mantic connection and Chapter 2 concludes that a direct connection with the Danes of Aqht, Ezek, and Jub, and with the angel in 1 Enoch should be rejected. There is evidence that the
tradition of a priest in Ezra 8: 2 and Neh 10: 7, and found also in the superscription to
the Old Greek of Bel, and 4 Ezra 12:10-11, and suggested the name.
Chapter 3 concludes that the portrayal of the court diviners in Dan 1-6 is wholly
negative and includes both the diviners, and the essence of the professions, i. e., the
ability to interpret a divine revelation. The critique is conveyed through the story line,
explicit criticisms, irony, and humour. Chapter 4 concludes that Daniel, the interpreter
of dreams and the writing on the wall, is distinguished from every other character and role. In the final form of Dan, Daniel as the divinely assisted each time he interprets, just as when he receives help from an interpreting angel in Dan 7-12.
Chapter 5 demonstrates that the portrayal of Daniel as the divinely assisted
interpreter makes sense of the reinterpretation of old prophecies against the Assyrians
as prophecies against Antiochus IV Epiphanes. Hab 2:2-4 and Isa 52-53 were also
understood as predictions about the maskilim themselves. Comparisons are then made
with the Teacher of Righteousness, the writers of the Hodayot, and with three Essenes
portrayed by Josephus. These too were portrayed as divinely assisted interpreters
Theodore R. Weeks. Nation and state in late imperial Russia. Nationalism and Russification on the Western Frontier, 1863-1914 : recenzija
No full text1996 m. pasirodžiusiTeodoro R. Weekso knyga atskleidžia imperinės Rusijos tautinę politiką XIX a. pab. – XX a. pr. Lenkijoje ir vadinamajame Šiaurės vakarų krašte. Knyga paremta solidžia archyvine medžiaga ir tinkamų šiai temai tyrimų duomenimis. Knygą sudaro devyni skyriai. Pirmuose dviejuose skyriuose pristatomos nacionalizmo teorijos ir imperinėje Rusijoje vykusios viešos diskusijos tautinių mažumų klausimais. Trečiame skyriuje nagrinėjamos Rusijos valdžios atstovų nuostatos minėtu klausimu. Ketvirta ir penkta knygos dalys skirtos apžvelgti Lenkijos ir Šiaurės vakarų krašto padėtį po 1863 m. sukilimo, aptarti imperinę rusifikacijos politiką. Šeštame leidinio skyriuje analizuojamos Lenkijoje ir Šiaurės vakarų krašte 1863–1914 m. aktyviai veikusių tautinių judėjimų politinės ambicijos ir imperijos reakcija. Trys paskutiniai skyriai skirti siauresniems Rusijos tautinės politikos aspektams aptarti. Knygos privalumu laikytinas Rusijos tautinės politikos analizės kompleksiškumas. Įdomu tai, jog Rusija daugiausia dėmesio skyrė lenkams ir žydams, o apie lietuvius beveik neužsiminta. Tarp studijos trūkumų atsiduria netolygus autoriaus dėmesys skirtingiems tyrimui pasirinkto laikotarpio momentams, nepakankama anuometinių „tautos“ ir „tautiškumo“ sampratų bei Rusijos politikos lietuvių atžvilgiu po 1863 m. sukilimo analizė, kai kada pernelyg kategoriški autoriaus teiginiai, abejotinas šiuolaikinių sąvokų taikymas imperinės Rusijos laikmečiui. Vis dėlto paminėti trūkumai ne mažina akademinę šio svarbaus veikalo vertę, o kviečia tolimesnei akademinei diskusijai. Reikšminiai žodžiai: Sukilimas, 1863-1864 (Lenkijos ir Lietuvos sukilimas; Sausio sukilimas; January Uprising); Tautinis atgimimas; Nacionalizmas; Polonizacija; Rusifikacija; Th.R.Weeks, tautinė valstybė, nacionalizmas, rusifikacija, imperinės Rusijos Vakarų regionas; Theodore R. Weeks; „Nation and State in Late Imperial Russia“; Nationalism; Th.R.Weeks, nation state, nationalism, russification, imperial Russia, Western borderlands; The Lithuanian National Revival; The Polonisation; The Russification; The Uprising of 1863; Theodore R. Weeks; „Nation and State in Late Imperial Russia“Theodore R. Weeks’ book that came out in 1996 uncovers imperial Russia’s national policy in Poland and the so-called Northwestern Krai in the late 19th - early 20th c. The book is based on solid archival material and relevant research data. The book consists of nine chapters. In the first two chapters, the theories of nationalism and the public discussion that took place in imperial Russia on the issues of ethnic minorities are presented. Chapter 3 examines the views of Russian authorities on said matter. The fourth and fifth parts of the book are devoted to examining the status of Poland and the Northwestern Krai after the January Uprising and discussing the imperial policy of Russification. In the sixth section of the publication, the political ambitions of the national movements that were active in Poland and the Northwestern Krai in 1863-1914 are analysed, as well as the Empire’s reaction. The final three chapters are devoted to discussing more narrow aspects of the Russian national policy. The complexity of analysis of the Russian national policy is considered to be the book’s strongpoint. Interestingly, Russia paid the most attention to the Poles and the Jews, and barely made mention of Lithuanians. The study’s flaws include the author’s unequal attention to different moments of the period selected for research, insufficient analysis of the concepts of the "nation" and "nationalism" of that time and the Russian policy in regards to Lithuanians after the January Uprising, assertions made by the author that are occasionally too categorical, and questionable application of modern concepts to the era of imperial Russia. Nevertheless, these shortcomings do not diminish the academic value of this important treatise, but rather - call for further academic discussion
Surplus Appropriation from R&D and Health Care Technology Assessment Procedures
No full textGiven the rapid growth in health care spending that is often attributed to technological change, many private and public institutions are grappling with how to best assess and adopt new health care technologies. The leading technology adoption criteria proposed in theory and used in practice involve so called "cost-effectiveness" measures. However, little is known about the dynamic efficiency implications of such criteria, in particular how they influence the R&D investments that make technologies available in the first place. We argue that such criteria implicitly concern maximizing consumer surplus, which many times is consistent with maximizing static efficiency after an innovation has been developed. Dynamic efficiency, however, concerns aligning the social costs and benefits of R&D and is therefore determined by how much of the social surplus from the new technology is appropriated as producer surplus. We analyze the relationship between cost-effectiveness measures and the degree of surplus appropriation by innovators driving dynamic efficiency. We illustrate how to estimate the two for the new HIV/AIDS therapies that entered the market after the late 1980's and find that only 5% of the social surplus is appropriated by innovators. We show how this finding can be generalized to other existing cost-effectiveness estimates by deriving how those estimates identify innovator appropriation for a set of studies of over 200 drugs. We find that these studies implicitly support a low degree of appropriation as well. Despite the high annual cost of drugs to patients, very low shares of social surplus may go to innovators, which may imply that cost-effectiveness is too high in a dynamic efficiency sense.
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