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Mapping tree canopies in urban environments using airborne laser scanning (ALS):a Vancouver case study

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Forest ecosystems 2018年第4期5卷 429-437页

作者： Giona Matasci nicholas C.Coops David A.R.williams Nick Page Department of Forest Resource Management Unlversity of British Columbia2424Main MallVancouverBC V6T IZ4Canada Vancouver Board of Parks and Recreation 2099Beach AvenueVancouverBC V6G IZ4Canada

Background: The distribution of forest vegetation within urban environments is critically important as it influences urban environmental conditions and the energy exchange through the absorption of solar radiation and modulation of evapotranspiration. It also plays an important role filtering urban water systems and reducing storm water ***: We investigate the capacity of ALS data to individually detect, map and characterize large(taller than15 m) trees within the City of Vancouver. Large trees are critical for the function and character of Vancouver’s urban forest. We used an object-based approach for individual tree detection and segmentation to determine tree locations(position of the stem), to delineate the shape of the crowns and to categorize the latter either as coniferous or ***: Results indicate a detection rate of 76.6% for trees > 15 m with a positioning error of 2.11 m(stem location). extracted tree heights possessed a RMSe of 2.60 m and a bias of-1.87 m, whereas crown diameter was derived with a RMSe of 3.85 m and a bias of-2.06 m. Missed trees are principally a result of undetected treetops occurring in dense, overlapping canopies with more accurate detection and delineation of trees in open ***: By identifying key structural trees across Vancouver’s urban forests, we can better understand their role in providing ecosystem goods and services for city residents.

关键词： Urban forest Large trees Light detection and ranging Airborne laser scanning

Utilizing zebrafish and okadaic acid to study Alzheimer's disease

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Neural Regeneration Research 2018年第9期13卷 1538-1541页

作者： Daniel Koehler Frederick e.williams Department of Pharmacology and experimental Therapeutics University of Toledo

Despite the many years of extensive research using rodent models to study Alzheimer＇s disease （AD）, no cure or disease halting drug exists. An increasing number of people are suffering from the disease and a therapeutic intervention is needed. Therefore, it is necessary to have complementary models to aid in the drug discovery. The zebrafish animal model is emerging as a valuable model for the investigation of AD and neurodegenerative drug discovery. The main genes involved in human AD have homologous counter- parts in zebrafish and have conserved function. The basic brain structure of the zebrafish is also conserved when compared to the mammalian brain. Recently an AD model was established by administering okadaic acid to zebrafish. It was used to test the efficacy of a novel drug, lanthionine ketimine-5-ethyl ester, and to elucidate its mechanism of action. This demonstrated the ability of the okadaic acid-induced AD zebrafish model to be implemented in the drug discovery process for therapeutics against AD.

关键词： Alzheimer's disease Zebrafish okadaic acid protein phosphatase 2A learning and memory lanthionine ketimine-5-ethyl ester

Late Cryogenian glaciation in South Australia:Fluctuating ice margin and no extreme or rapid post-glacial sea-level rise

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Geoscience Frontiers 2019年第4期10卷 1397-1408页

作者： George e.williams Victor A.Gostin Department of earth Sciences University of Adelaide

Postulated extreme sea-level rise of up to 1-1.5 km with the late Cryogenian Ghaub deglaciation in Namibia is contentious,as is the great rapidity(<104 yr)of the sea-level *** extreme glacioeustatic events,if real,wou... 详细信息

Postulated extreme sea-level rise of up to 1-1.5 km with the late Cryogenian Ghaub deglaciation in Namibia is contentious,as is the great rapidity(e sea-level *** extreme glacioeustatic events,if real,would have been global and affected all *** South Australia,up to six glacial advances and retreats during the late Cryogenian elatina glaciation indicate a fluctuating ice *** latter stage of the elatina glaciation and the immediate post-glacial environment are examined here for evidence of extreme and rapid sea-level *** the central Adelaide Rift Complex,diamictite with faceted and striated clasts occurs at the top of the elatina Formationeneath the early ediacaran Nuccaleena Formation’cap carbonate’.One hundred kilometres to the south,~30 m of siltstone and sandstone followed by^6 m of clast-poor diamictite with clasts 10+cm long occur between tidal rhythmites and the cap *** hundred kilo metres further south,~70 m of siltsto ne,dolo mitic siltstone and minor dolomite separate tidal rhythmites and early ediacaran *** the rhythmites were deposited during a high stand(interstadial or interglacial),not during post-glacial sea-level ***-generated erosional surfaces within tidal rhythmites at Warren Gorge indicate intermittent rhythmite deposition,and water depth and other palaeoenvironmental factors are uncertain,casting doubt on a published estimate of rapid sea-level rise during rhythmite *** lack of late Cryogenian deeply incised valleys and thick valley-fill deposits in South Australia and central Australia argues against extreme sea-level variations.A hiatus occurred between elatina deglaciation and deposition of the Nuccaleena cap carbonate,and three palaeomagnetic polarity chrons identified in the cap carbonate imply slow deposition spanning 10^5-10^6 *** is supported by independent evidence from magnetic chronostratigraphy for ediacaran strata in South Australia and Califo

关键词： Late Cryogenian glaciation Sea level Adelaide Rift Complex elatina Formation Nuccaleena Formation

Shuram-Wonoka carbon isotope excursion:ediacaran revolution in the world ocean's meridional overturning circulation

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Geoscience Frontiers 2018年第2期9卷 391-402页

作者： George e.williams Phillip W.Schmidt Department of earth Sciences University of Adelaide Magneticearth

The late ediacaran Shuram-Wonoka excursion, with δ^(13)C_(carb) values as low as-12‰(PDB) in marineshelf deposits and spanning up to 10 Myr, is the deepest and most protracted δ^(13)C_(carb) negative anomaly recognised in earth history. The excursion formed on at least four continents in low(≤32°) palaeolatitudes, and in China is associated with a major phosphogenic event. Global and intrabasinal correlation, magnetostratigraphy, isotope conglomerate tests and further geochemical data are consistent with a primary or syn-depositional origin for the excursion. Continental-margin phosphorites are generated by oceanic upwelling driven by surface winds, and δ^(13)C_(carb) negative anomalies are explicable by oceanic upwelling of 13 C-depleted deep oceanic waters, arguing that a feature common to these exceptional ediacaran events was unprecedented perturbation of the world ocean. These events occurred during the transition from an alien Proterozoic world marked by low-palaeolatitude glaciation near sea level and strong seasonality to the familiar Phanerozoic earth with circum-polar glaciation and temperate climate, suggesting that the Shuram-Wonoka excursion is related to this profound change in earth's climate system. Of various hypotheses for Proterozoic low-palaeolatitude glaciation, only the high obliquity(>54°) hypothesis, which posits secular decrease in obliquity to near the present-day value(23.5°) during the ediacaran, predicts an unparalleled revolution in the ediacaran world ocean. The obliquity controls the sense of the world ocean's meridional overturning circulation, which today is driven by the sinking of cold, dense water at the poles and upwelling driven by zonal surface *** the decreasing obliquity passed the critical value of 54° during the ediacaran the meridional temperature gradient reversed, with the equator becoming warmer than the poles and Hadley lowlatitude(eric zonal circulation reversing. This reversal of the temperat

关键词： ediacaran Shuram-Wonoka carbon isotope excursion Oceanic meridional circulation Atmospheric circulation Proterozoic paleoclimate Obliquity of the ecliptic

Two More Fragmentary Folios from the Book of Zambasta?

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敦煌吐鲁番研究

敦煌吐鲁番研究 2023年第1期 1-13,447-448页

作者： nicholas Sims-williams 英國倫敦大學亞非學院

The Book of Zambasta(abbreviated‘Z’)is a long poem in Old Khotanese which has been described as’a veritable Manual of Buddhism’.[1]The best-preserved copy,sometimes referred to as‘Z1’,seems to have formed part of a manuscript miscellany,in which the 24 chapters of Z occupied folios 143 verso to 440 *** these 298 folios,more than two thirds are still extant in whole or *** Z1each verse is written on a single line,with six lines to the *** text is presented in four columns separated by spaces which in principle correspond to the caesurae between the four padas(‘abcd’)of the *** verse number is frequently indicated at the end of the line,often in abbreviated form(e.g.‘2’in place of‘52’,or‘52’in place of‘152’).

关键词： abbreviated occupied columns

east African topography and volcanism explained by a single,migrating plume

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Geoscience Frontiers 2020年第5期11卷 1669-1680页

作者： Rakib Hassan Simon e.williams Michael Gurnis Dietmar Muller School of Geosciences Room 412Madsen Building F09 Eastern AvenueThe University of SydneyNSW2006Australia Seismological Laboratory California Institute of TechnologyPasadenaCA91125USA Now at Geoscience Australia GPO Box 378CanberraACT2601Australia State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi’an 710069China

Anomalous topographic swells and Cenozoic volcanism in east Africa have been associated with mantle *** models involving one or more fixed plumes beneath the northeastward migrating African plate have been suggested to explain the space-time distribution of magmatism in east *** devise paleogeographically constrained global models of mantle convection and,based on the evolution of flow in the deepest lower mantle,show that the Afar plume migrated southward throughout its *** models suggest that the mobile Afar plume provides a dynamically consistent explanation for the spatial extent of the southward propagation of the east African rift system(eARS),which is difficult to explain by the northeastward migration of Africa over one or more fixed plumes alone,over the last≈45 *** further show that the age-progression of volcanism associated with the southward propagation of eARS is consistent with the apparent surface hotspot motion that results from southward motion of the modelled Afar plume beneath the northeastward migrating African *** models suggest that the Afar plume became weaker as it migrated southwards,consistent with trends observed in the geochemical record.

关键词： Numerical mantle flow models Deep mantle flow LLSVP morphology Plume dynamics Plume motion Dynamic topography

Advanced biomedical hydrogels:molecular architecture and its impact on medical applications

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Regenerative Biomaterials 2021年第6期8卷 297-317页

作者： Jonathan T.Peters Marissa e.Wechsler nicholas A.Peppas McKetta Department of Chemical engineering The University of Texas at AustinAustin200 E.Dean KeetonAustinTX 78712USA Institute for Biomaterials Drug Deliveryand Regenerative MedicineThe University of Texas at Austin107 W.Dean KeetonAustinTX 78712USA Department of Biomedical engineering and Chemical engineering The University of Texas at San AntonioOne UTSA CircleSan AntonioTX78249USA Department of Biomedical engineering The University of Texas at Austin107 W.Dean KeetonAustinTX 78712USA Division of Molecular Pharmaceutics and Drug Delivery College of PharmacyThe University of Texas at Austin107 W.Dean KeetonAustinTX 78712USA Department of Surgery and Perioperative Care and Department of PediatricsDell Medical SchoolThe University of Texas at Austin1601 Trinity St.Bldg.BAustinTX 78712USA

Hydrogels are cross-linked polymeric networks swollen in water,physiological aqueous solutions or biological *** are synthesized by a wide range of polymerization methods that allow for the introduction of linear and branched units with specific molecular *** addition,they can be tuned to exhibit desirable chemical characteristics including hydrophilicity or *** synthesized hydrogels can be anionic,cationic,or amphiphilic and can contain multifunctional crosslinks,junctions or tie *** these characteristics,hydrogels exhibit compatibility with biological systems,and can be synthesized to render systems that swell or collapse in response to external *** versatility and compatibility have led to better understanding of how the hydrogel’s molecular architecture will affect their physicochemical,mechanical and biological *** present a critical summary of the main methods to synthesize hydrogels,which define their architecture,and advanced structural characteristics for macromolecular/biological applications.

关键词： hydrogels networks mesh size hydrogel reactions biological applications biomedical applications

Colonic lesion characterization in inflammatory bowel disease:A systematic review and meta-analysis

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World Journal of Gastroenterology 2018年第10期24卷 1167-1180页

作者： Richard Lord nicholas e Burr Noor Mohammed Venkataraman Subramanian Department of Gastroenterology Leeds Teaching Hospitals NHS TrustLeeds LS97TFUnited Kingdom University of Leeds Leeds Institute of Biomedical and Clinical SciencesLeeds LS97TFUnited Kingdom

AIM To perform a systematic review and meta-analysis for the diagnostic accuracy of in vivo lesion characterization in colonic inflammatory bowel disease(IBD), using optical imaging techniques, including virtual chromoendoscopy(VCe), dye-based chromoendoscopy(DBC), magnification endoscopy and confocal laser endomicroscopy(CLe). MeTHODS We searched Medline, embase and the Cochrane library. We performed a bivariate meta-analysis to calculate the pooled estimate sensitivities, specificities, positive and negative likelihood ratios(+LHR,-LHR), diagnostic odds ratios(DOR), and area under the SROC curve(AUSROC) for each technology group. A subgroup analysis was performed to investigate differences in real-time nonmagnified Kudo pit patterns(with VCe and DBC) and real-time *** We included 22 studies [1491 patients; 4674 polyps, of which 539(11.5%) were neoplastic]. Real-time CLe had a pooled sensitivity of 91%(95%CI: 66%-98%), specificity of 97%(95%CI: 94%-98%), and an AUSROC of 0.98(95%CI: 0.97-0.99). Magnification endoscopy had a pooled sensitivity of 90%(95%CI: 77%-96%)and specificity of 87%(95%CI: 81%-91%). VCe had a pooled sensitivity of 86%(95%CI: 62%-95%) and specificity of 87%(95%CI: 72%-95%). DBC had a pooled sensitivity of 67%(95%CI: 44%-84%) and specificity of 86%(95%CI: 72%-94%). CONCLUSION Real-time CLe is a highly accurate technology for differentiating neoplastic from non-neoplastic lesions in patients with colonic IBD. However, most CLe studies were performed by single expert users within tertiary centres, potentially confounding these results.

关键词： Inflammatory bowel disease dysplasia Lesion characterization Confocal laser endomicroscopy Narrow band imaging I-scan Fujinon intelligence chromoendoscopy

Crustacean parasites associated with hermit crabs from the western Mediterranean Sea,with first documentation of egg predation by the burrowing barnacle Trypetesa lampas(Cirripedia:Acrothoracica:Trypetesidae)

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Integrative Zoology 2011年第1期6卷 13-27页

作者： Jason D.williams Alejandra GALLARDO Angela e.MURPHY Department of Biology Hofstra UniversityHempsteadNYUSA

Parasitic isopods(family Bopyridae)and burrowing barnacles(family Trypetesidae)infesting hermit crabs were investigated from shallow subtidal collections made along the southeastern coast of Spain in 2009.A total of 713 specimens of Clibanarius erythropus(Latreille,1818)and 82 Calcinus tubularis(L.,1767)were *** shells and worm tubes inhabited by hermit crabs were collected by hand while snorkeling and were cracked to determine host species,size,sex and presence of *** species of bopyrid isopods were found on ***:the branchial parasite Bopyrissa fraiseii(Carayon,1943)and the abdominal parasite Parathelges cardonae Codreanu and Codreanu in Codreanu,*** all *** examined,Bopyrissa fraiseii was found on 0.6%of hermit crabs and *** was found on 0.3%.A redescription of *** is provided and the species is documented with light and scanning electron microscopy for the first *** Calcinus tubularis harbored parasitic isopods,but one specimen was parasitized by an unidentified rhizocephalan barnacle of the genus Septosaccus(1.2%).The burrowing barnacle Trypetesa lampas(Hancock,1849)was found associated with both hermit crab species and evidence of predation on host eggs by this barnacle is shown for the first *** lampas was found in 4.2%of the shells *** present study expands our knowledge of the parasite fauna of hermit crabs from the Mediterranean Sea and indicates that additional research is needed to determine the impact of trypetesid egg predators on hermit crab populations.

关键词： Bopyridae egg predator Isopoda parasitism Rhizocephala