Dead wood such as coarse dead wood debris (CWD) is an important component in natural forests since it increases the diversity of plants, fungi, and animals. It serves as habitat, provides nutrients ...and is conducive to forest regeneration, ecosystem stabilization and soil protection. In commercially operated forests, dead wood is often unwanted as it can act as an originator of calamities. Accordingly, efficient CWD monitoring approaches are needed. However, due to the small size of CWD objects satellite data-based approaches cannot be used to gather the needed information and conventional ground-based methods are expensive. Unmanned aerial systems (UAS) are becoming increasingly important in the forestry sector since structural and spectral features of forest stands can be extracted from the high geometric resolution data they produce. As such, they have great potential in supporting regular forest monitoring and inventory. Consequently, the potential of UAS imagery to map CWD is investigated in this study. The study area is located in the center of the Hainich National Park (HNP) in the federal state of Thuringia, Germany. The HNP features natural and unmanaged forest comprising deciduous tree species such as Fagus sylvatica (beech), Fraxinus excelsior (ash), Acer pseudoplatanus (sycamore maple), and Carpinus betulus (hornbeam). The flight campaign was controlled from the Hainich eddy covariance flux tower located at the Eastern edge of the test site. Red-green-blue (RGB) image data were captured in March 2019 during leaf-off conditions using off-the-shelf hardware. Agisoft Metashape Pro was used for the delineation of a three-dimensional (3D) point cloud, which formed the basis for creating a canopy-free RGB orthomosaic and mapping CWD. As heavily decomposed CWD hardly stands out from the ground due to its low height, it might not be detectable by means of 3D geometric information. For this reason, solely RGB data were used for the classification of CWD. The mapping task was accomplished using a line extraction approach developed within the object-based image analysis (OBIA) software eCognition. The achieved CWD detection accuracy can compete with results of studies utilizing high-density airborne light detection and ranging (LiDAR)-based point clouds. Out of 180 CWD objects, 135 objects were successfully delineated while 76 false alarms occurred. Although the developed OBIA approach only utilizes spectral information, it is important to understand that the 3D information extracted from our UAS data is a key requirement for successful CWD mapping as it provides the foundation for the canopy-free orthomosaic created in an earlier step. We conclude that UAS imagery is an alternative to laser data in particular if rapid update and quick response is required. We conclude that UAS imagery is an alternative to laser data for CWD mapping, especially when a rapid response and quick reaction, e.g., after a storm event, is required.
Accurate detection and delineation of individual trees and their crowns in dense forest environments are essential for forest management and ecological applications. This study explores the potential ...of combining leaf-off and leaf-on structure from motion (SfM) data products from unoccupied aerial vehicles (UAVs) equipped with RGB cameras. The main objective was to develop a reliable method for precise tree stem detection and crown delineation in dense deciduous forests, demonstrated at a structurally diverse old-growth forest in the Hainich National Park, Germany. Stem positions were extracted from the leaf-off point cloud by a clustering algorithm. The accuracy of the derived stem co-ordinates and the overall UAV-SfM point cloud were assessed separately, considering different tree types. Extracted tree stems were used as markers for individual tree crown delineation (ITCD) through a region growing algorithm on the leaf-on data. Stem positioning showed high precision values (0.867). Including leaf-off stem positions enhanced the crown delineation, but crown delineations in dense forest canopies remain challenging. Both the number of stems and crowns were underestimated, suggesting that the number of overstory trees in dense forests tends to be higher than commonly estimated in remote sensing approaches. In general, UAV-SfM point clouds prove to be a cost-effective and accurate alternative to LiDAR data for tree stem detection. The combined datasets provide valuable insights into forest structure, enabling a more comprehensive understanding of the canopy, stems, and forest floor, thus facilitating more reliable forest parameter extraction.
Leveraging low-cost drone technology, specifically the DJI Mini 2, this study presents an innovative method for creating accurate, high-resolution digital surface models (DSMs) to enhance topographic ...mapping with off-the-shelf components. Our research, conducted near Jena, Germany, introduces two novel flight designs, the “spiral” and “loop” flight designs, devised to mitigate common challenges in structure from motion workflows, such as systematic doming and bowling effects. The analysis, based on height difference products with a lidar-based reference, and curvature estimates, revealed that “loop” and “spiral” flight patterns were successful in substantially reducing these systematic errors. It was observed that the novel flight designs resulted in DSMs with lower curvature values compared to the simple nadir or oblique flight patterns, indicating a significant reduction in distortions. The results imply that the adoption of novel flight designs can lead to substantial improvements in DSM quality, while facilitating shorter flight times and lower computational needs. This work underscores the potential of consumer-grade unoccupied aerial vehicle hardware for scientific applications, especially in remote sensing tasks.
Forests’ ecosystems are an essential part of the global carbon cycle with vast carbon storage potential. These systems are currently under external pressures showing increasing change due to climate ...change. A better understanding of the biophysical properties of forests is, therefore, of paramount importance for research and monitoring purposes. While there are many biophysical properties, the focus of this study is on the in-depth analysis of the connection between the C-band Copernicus Sentinel-1 SAR backscatter and evapotranspiration (ET) estimates based on in situ meteorological data and the FAO-based Penman–Monteith equation as well as the well-established global terrestrial ET product from the Terra and Aqua MODIS sensors. The analysis was performed in the Free State of Thuringia, central Germany, over coniferous forests within an area of 2452 km2, considering a 5-year time series (June 2016–July 2021) of 6- to 12-day Sentinel-1 backscatter acquisitions/observations, daily in situ meteorological measurements of four weather stations as well as an 8-day composite of ET products of the MODIS sensors. Correlation analyses of the three datasets were implemented independently for each of the microwave sensor’s acquisition parameters, ascending and descending overpass direction and co- or cross-polarization, investigating different time series seasonality filters. The Sentinel-1 backscatter and both ET time series datasets show a similar multiannual seasonally fluctuating behavior with increasing values in the spring, peaks in the summer, decreases in the autumn and troughs in the winter months. The backscatter difference between summer and winter reaches over 1.5 dB, while the evapotranspiration difference reaches 8 mm/day for the in situ measurements and 300 kg/m2/8-day for the MODIS product. The best correlation between the Sentinel-1 backscatter and both ET products is achieved in the ascending overpass direction, with datasets acquired in the late afternoon, and reaches an R2-value of over 0.8. The correlation for the descending overpass direction reaches values of up to 0.6. These results suggest that the SAR backscatter signal of coniferous forests is sensitive to the biophysical property evapotranspiration under some scenarios.
Virus-specific antibodies are crucial for protective immunity against SARS-CoV-2. Assessing functional antibodies through conventional or pseudotyped virus neutralisation tests (pVNT) requires high ...biosafety levels. Alternatively, the virus-free surrogate virus neutralisation test (sVNT) quantifies antibodies interfering with spike binding to angiotensin-converting enzyme 2. We evaluated secreted nanoluciferase-tagged spike protein fragments as diagnostic antigens in the sVNT in a vaccination cohort. Initially, spike fragments were tested in a capture enzyme immunoassay (EIA), identifying the receptor binding domain (RBD) as the optimal diagnostic antigen. The sensitivity of the in-house sVNT applying the nanoluciferase-labelled RBD equalled or surpassed that of a commercial sVNT (
, GenScript Diagnostics) and an in-house pVNT four weeks after the first vaccination (98% vs. 94% and 72%, respectively), reaching 100% in all assays four weeks after the second and third vaccinations. When testing serum reactivity with Omicron BA.1 spike, the sVNT and pVNT displayed superior discrimination between wild-type- and variant-specific serum reactivity compared to a capture EIA. This was most pronounced after the first and second vaccinations, with the third vaccination resulting in robust, cross-reactive BA.1 construct detection. In conclusion, utilising nanoluciferase-labelled antigens permits the quantification of SARS-CoV-2-specific inhibitory antibodies. Designed as flexible modular systems, the assays can be readily adjusted for monitoring vaccine efficacy.
There is no doubt that unmanned aerial systems (UAS) will play an increasing role in Earth observation in the near future. The field of application is very broad and includes aspects of environmental ...monitoring, security, humanitarian aid, or engineering. In particular, drones with camera systems are already widely used. The capability to compute ultra-high-resolution orthomosaics and three-dimensional (3D) point clouds from UAS imagery generates a wide interest in such systems, not only in the science community, but also in industry and agencies. In particular, forestry sciences benefit from ultra-high-structural and spectral information as regular tree level-based monitoring becomes feasible. There is a great need for this kind of information as, for example, due to the spring and summer droughts in Europe in the years 2018/2019, large quantities of individual trees were damaged or even died. This study focuses on selective logging at the level of individual trees using repeated drone flights. Using the new generation of UAS, which allows for sub-decimeter-level positioning accuracies, a change detection approach based on bi-temporal UAS acquisitions was implemented. In comparison to conventional UAS, the effort of implementing repeated drone flights in the field was low, because no ground control points needed to be surveyed. As shown in this study, the geometrical offset between the two collected datasets was below 10 cm across the site, which enabled a direct comparison of both datasets without the need for post-processing (e.g., image matching). For the detection of logged trees, we utilized the spectral and height differences between both acquisitions. For their delineation, an object-based approach was employed, which was proven to be highly accurate (precision = 97.5%; recall = 91.6%). Due to the ease of use of such new generation, off-the-shelf consumer drones, their decreasing purchase costs, the quality of available workflows for data processing, and the convincing results presented here, UAS-based data can and should complement conventional forest inventory practices.
In this study, a dense Copernicus Sentinel-1 time series is analyzed to gain a better understanding of the influence of undergrowth vegetation, in particular of eagle fern (Pteridium aquilinum), on ...the C-band SAR signal in a temperate forest in the Free State of Thuringia, Germany. Even if signals from the ground below the canopy may not be expected at C-band, previous studies showed seasonal fluctuations of the backscatter for temperate forests without canopy closure, notably for evergreen coniferous stands. Many factors can be responsible for these observed fluctuations, but in this study, we analyze one possible factor: the presence of undergrowth vegetation, in particular, of fern. Especially, the Sentinel-1 backscatter signal is analyzed for different acquisition configurations regarding its temporal and its spatial stability at different growth stages. This time series study shows that a difference of backscattered signal of up to 0.7 dB exists between forest patches with a dense fern density in the understory and the ones with low undergrowth vegetation. This signal difference depends on the season and is remarkably strong comparing winter (no fern undergrowth) with summer (major fern undergrowth).
Prelingual non-syndromic (isolated) deafness is the most frequent hereditary sensory defect. In >80% of the cases, the mode of transmission is autosomal recessive. To date, 14 loci have been ...identified for the recessive forms (DFNB loci). For two of them, DFNB1 and DFNB2, the genes responsible have been characterized; they encode connexin 26 and myosin VIIA, respectively. In order to evaluate the extent to which the connexin 26 gene (Cx26) contributes to prelingual deafness, we searched for mutations in this gene in 65 affected Caucasian families originating from various countries, mainly Tunisia, France, New Zealand and the UK. Six of these families are consanguineous, and deafness was shown to be linked to the DFNB1 locus, 10 are small non consanguineous families in which the segregation of the trait has been found to be compatible with the involvement of DFNB1, and in the remaining 49 families no linkage analysis has been performed. A total of 62 mutant alleles in 39 families were identified. Therefore, mutations in Cx26 represent a major cause of recessively inherited prelingual deafness since according to the present results they would underlie approximately half of the cases. In addition, one specific mutation, 30delG, accounts for the majority (∼70%) of the Cx26 mutant alleles. It is therefore one of the most frequent disease mutations so far identified. Several lines of evidence indicate that the high prevalence of the 30delG mutation arises from a mutation hot spot rather than from a founder effect. Genetic counselling for prelingual deafness has been so far considerably impaired by the difficulty in distinguishing genetic and non genetic deafness in families presenting with a single deaf child. Based on the results presented here, the development of a simple molecular test could be designed which should be of considerable help.
New books in review Glancy, Donald R.; Kennedy, Theodore R.; Sillars, Malcolm O. ...
Quarterly Journal of Speech,
12/1/1968, 1968-12-00, Letnik:
54, Številka:
4
Book Review, Journal Article
Recenzirano
ROOSEVELT AND WILLKIE: THE PRECEDENT BREAKING PRESIDENTIAL CAMPAIGN OF 1940-ITS ANTAGONISTS, ITS BATTLES, ITS IMPACT. By Warren Moscow. Englewood Cliffs, N. J.: Prentice-Hall, 1968; pp. xi+210. ...$6.95.
REORGANIZING ROOSEVELT'S GOVERNMENT: THE CONTROVERSY OVER EXECUTIVE REORGANIZATION, 1936-1939. By Richard Polenberg. Cambridge, Mass.: Harvard University Press, 1966; pp. viii+275. $5.95.
THE PRESIDENT AS CHIEF ADMINISTRATOR: A STUDY OF FRANKLIN D. ROOSEVELT. By A. J. Wann. Washington, D. C: Public Affairs Press, 1968; pp. v+219. $6.00.
THE COMMITTEE: THE EXTRAORDINARY CAREER OF THE HOUSE COMMITTEE ON UN-AMERICAN ACTIVITIES. By Walter Goodman. New York: Farrar, Straus and Giroux, 1968; pp. xviii+564. $10.00.
THE KU KLUX KLAN IN THE CITY, 1915-1930. By Kenneth T. Jackson. Foreword by Richard C. Wade. (Urban Life in America Series.) New York: Oxford University Press, 1967; pp. xv+326. $7.50.
POLITICS AND DIPLOMACY OF PEACEMAKING: CONTAINMENT AND COUNTERREVOLUTION AT VERSAILLES, 1918-1919. By Arno J. Mayer. New York: Alfred A. Knopf, 1967; pp. vii+918+xx. $15.00.
THE PAPERS OF WOODROW WILSON, VOLUME III, FEBRUARY 1884-JANUARY 1885. Edited by Arthur S. Link. Princeton, N. J.: Princeton University Press, 1967; pp. xi+648. $15.00.
WOODROW WILSON: A PROFILE. Edited by Arthur S. Link. New York: Hill and Wang, 1968; pp. xxi+197. $5.95.
WILLIAM JAMES: A BIOGRAPHY. By Gay Wilson Allen. New York: Viking Press, 1967; pp. xx+556. $10.00.
THE SOUTH REJECTS A PROPHET: THE LIFE OF SENATOR D. M. KEY, 1824-1900. By David M. Abshire. Foreword by Ralph McGill. New York: Praeger, 1967; pp. xii+250. $5.95.
THE RECONSTRUCTION OF THE NATION. By Rembert W. Patrick. New York: Oxford University Press, 1967; pp. xi+324. $7.50.
AN ANALYSIS OF LINCOLN AND DOUGLAS AS PUBLIC SPEAKERS AND DEBATERS. By Lionel Crocker. Springfield: Charles C Thomas, 1968; pp. xviii+550. $15.50.
AARON BURR: PORTRAIT OF AN AMBITIOUS MAN. By Herbert S. Parmet and Marie B. Hecht. New York: Macmillan, 1967; pp. xii+399. $8.95.
LORD NORTH. By Alan Valentine. (Two volumes.) Norman: University of Oklahoma Press, 1967; Vol. I, pp. xi+568; Vol. II, pp. 517. $19.95.
THE CHATHAMITES: A STUDY IN THE RELATIONSHIP BETWEEN PERSONALITIES AND IDEAS IN THE SECOND HALF OF THE EIGHTEENTH CENTURY. By Peter Brown. New York: St. Martins, 1967; pp. xv+516. $15.00.
RHETORIC: A SYNTHESIS. By W. Ross Win-terowd. New York: Holt, Rinehart, and Winston, 1968; pp. xii+228. $5.95.
LECTURES READ TO THE SENIORS IN HARVARD COLLEGE. (Landmarks in Rhetoric and Public Address Series.) By Edward T. Channing. Edited with a critical introduction by Dorothy I. Anderson and Waldo W. Braden. Foreword by David Potter. Carbon-dale: Southern Illinois University Press, 1968; pp. liv+xx+303. $10.00.
A BIBLIOGRAPHY OF JOSEPH PRIESTLEY, 1733-1804. By Ronald E. Crook. London: Library Association, 1966; pp. xiv+202. $5.76.
THE FORMATION OF ENGLISH NEO-CLASSICAL THOUGHT. By James William Johnson. Princeton: Princeton University Press, 1967; pp. xxi+359. $9.00.
THE ELOQUENT "I": STYLE AND SELF IN SEVENTEENTH-CENTURY PROSE. By Joan Webber. Madison: University of Wisconsin Press, 1968; pp. xiv+298. $8.50.
THE RISE OF MODERN PROSE STYLE. By Robert Adolph. Cambridge, Mass.: M.I.T. Press, 1968; pp. x+372. $12.50.
CICERO'S LETTERS TO ATTICUS: VOLUME V. Edited by D. R. Shackleton Bailey. New York: Cambridge University Press, 1966; pp. xi+428. $11.50.
CICERO'S LETTERS TO ATTICUS: VOLUME VI. Edited by D. R. Shackleton Bailey. New York: Cambridge University Press, 1967; pp. viii+331. $9.50.
CICERO: ON OLD AGE AND ON FRIENDSHIP. Translated with an introduction by Frank Q. Copley. Ann Arbor: University of Michigan Press, 1967; pp. XV1+115. $4.95.
LANGUAGE AND SYMBOLIC SYSTEMS. By Yuen Ren Chao. New York: Cambridge University Press, 1968; pp. xv+240. $5.00; paper $1.95.
DEVELOPMENTS IN APPLIED PSYCHOLIN-GUISTICS RESEARCH. Edited by Sheldon Rosenberg and James H. Koplin. New York: Macmillan, 1968; pp. vii+311. $8.95.
TRAGIC THEORY AND THE EIGHTEENTH-CENTURY FRENCH CRITICS. By James Herbert Davis, Jr. (University of North Carolina Studies in the Romance Languages and Literatures, No. 68.) Chapel Hill: University of North Carolina Press, 1967; pp. 121. $3.50.
BERNARD SHAW AND THE THEATER IN THE NINETIES: A STUDY OF SHAW'S DRAMATIC CRITICISM. By Harold Fromm. Lawrence, Kansas: University of Kansas Press, 1967; pp. viii+234. $5.00.
SHAW AND THE CHARLATAN GENIUS: A MEMOIR. By John O'Donovan. Chester Springs, Pa.: Dufour, 1966; pp. 160. $4.50.
MAX FRISCH. By Ulrich Weisstein. (Twayne's World Authors Series, No. 21.) New York: Twayne, 1967; pp. 192. $4.50.
A THEATRE DIVIDED: THE POSTWAR AMERICAN STAGE. By Martin Gottfried. Boston: Little, Brown, 1967; pp. 330. $7.50.
FOGIE: THE LIFE OF ELSIE FOGERTY. By Marion Cole. Foreword by Sir Laurence Olivier. New York: Hillary House, 1968; pp. x+229. $8.50.
TWO PLAYS OF ANCIENT INDIA: THE LITTLE CLAY CART AND THE MINISTER'S SEAL. Translated by J. A. B. von Buitenen. Foreword by Ainslie T. Embree. New York: Columbia University Press, 1968; pp. viii+278. $7.50.
THE TRIUMPHS AND TRIALS OF LOTTA CRABTREE. By David Dempsey with Raymond P. Baldwin. New York: William Morrow, 1968; pp. viii+341. $6.93.
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