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Volcano video data characterized and classified using computer vision and machine learning algorithms

Geoscience Frontiers 2020年第5期11卷 1789-1803页

作者： Alex j.C.Witsil jeffrey b.johnson Department of Geosciences Boise State UniversityBoiseIDUSA

Video cameras are common at volcano observatories,but their utility is often limited during periods of crisis due to the large data volume from continuous acquisition and time requirements for manual *** cameras to serve as effective monitoring tools,video frames must be synthesized into relevant time series signals and further analyzed to classify and characterize observable *** this study,we use computer vision and machine learning algorithms to identify periods of volcanic activity and quantify plume rise velocities from video *** were collected at Villarrica Volcano,Chile from two visible band cameras located^17 km from the vent that recorded at 0.1 and 30 frames per second between February and April *** these two months,Villarrica exhibited a diverse range of eruptive activity,including a paroxysmal eruption on 3 *** to and after the eruption,activity included nighttime incandescence,dark and light emissions,inactivity,and periods of cloud *** quantify the color and spatial extent of plume emissions using a blob detection algorithm,whose outputs are fed into a trained artificial neural network that categorizes the observable activity into five *** shifts from primarily nighttime incandescence to ash emissions following the 3 March paroxysm,which likely relates to the reemergence of the buried lava *** periods exhibiting plume emissions are further analyzed using a row and column projection algorithm that identifies plume onsets and calculates apparent plume horizontal and vertical rise *** onsets are episodic,occurring with an average period of^50 s and suggests a puffing style of degassing,which is commonly observed at ***,the lack of clear acoustic transients in the accompanying infrasound record suggests puffing may be controlled by atmospheric effects rather than a degassing regime at the *** presented here offer a generalized toolset for volcano monito

关键词： Volcano monitoring Plume exit velocity Volcano webcam Image processing Machine learning Villarrica

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Modeling the impact of quarantine during an outbreak of Ebola virus disease

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Infectious Disease Modelling 2019年第1期4卷 12-27页

作者： Attila Dénes Abba b.Gumel bolyai Institute University of SzegedAradi vertanúk tere 1.Szeged H-6720Hungary School of Mathematical and Statistical Sciences Arizona State UniversityTempeAZ 85287-1804USA Other affliation:Department of Mathematics and Applied Mathematics University of PretoriaPretoria 0002South Africa

The quarantine of people suspected of being exposed to an infectious agent is one of the most basic public health measure that has historically been used to combat the spread of communicable diseases in human *** study presents a new deterministic model for assessing the population-level impact of the quarantine of individuals suspected of being exposed to disease on the spread of the 2014e2015 outbreaks of Ebola viral *** is assumed that quarantine is imperfect(i.e.,individuals can acquire infection during quarantine).In the absence of quarantine,the model is shown to exhibit global dynamics with respect to the disease-free and its unique endemic equilibrium when a certain epidemiological threshold(denoted byR 0)is either less than or greater than ***,unlike the full model with imperfect quarantine(which is known to exhibit the phenomenon of backward bifurcation),the version of the model with no quarantine does not undergo a backward *** data relevant to the 2014e2015 Ebola transmission dynamics in the three West African countries(Guinea,Liberia and Sierra Leone),uncertainty analysis of the model show that,although the current level and effectiveness of quarantine can lead to significant reduction in disease burden,they fail to bring the associated quarantine reproduction number(R Q0)to a value less than unity(which is needed to make effective disease control or elimination feasible).This reduction of R Q0 is,however,very possible with a modest increase in quarantine rate and *** is further shown,via sensitivity analysis,that the parameters related to the effectiveness of quarantine(namely the parameter associated with the reduction in infectiousness of infected quarantined individuals and the contact rate during quarantine)are the main drivers of the disease transmission ***,this study shows that the singular implementation of a quarantine intervention strategy can lead to the effective control or

关键词： Ebola virus disease Quarantine Global dynamics

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A survey of FLS2 genes from multiple citrus species identifies candidates for enhancing disease resistance to Xanthomonas citri ssp. citri.

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Horticulture Research 2016年第1期3卷 208-218页

作者： Qingchun Shi Vicente j Febres jeffrey b j.nes Gloria A Moore Horticultural Sciences Department University of FloridaGainesvilleFL 32611USA Plant Molecular and Cellular biology Program University of FloridaGainesvilleFL 32611USA Plant Pathology Department University of FloridaGainesvilleFL 32611USA

Pathogen-associated molecular patterns(PAMPs)-triggered immunity(PTI)is an important component of plant innate *** a previous study,we showed that the PAMP flg22 from Xanthomonas citri ***(Xflg22),the causal agent of citrus canker,induced PTI in citrus,which correlated with the observed levels of canker ***,we identified and sequenced two bacterial flagellin/flg22 receptors(FLS2-1 and FLS2-2)from‘Duncan’grapefruit(Citrus paradisi,CpFLS2-1 and CpFLS2-2)and‘Sun Chu Sha’mandarin(***,CrFLS2-1 and CrFLS2-2).We were able to isolate only one FLS2 from‘Nagami’kumquat(Fortunella margarita,FmFLS2-1)and gene flanking sequences suggest a rearrangement event that resulted in the deletion of FLS2-2 from the *** analysis,gene structure and presence of critical amino acid domains all indicate we identified the true FLS2 genes in ***2-2 was more transcriptionally responsive to Xflg22 than FLS2-1,with induced expression levels higher in canker-resistant citrus than in susceptible ***,‘Nagami’kumquat showed the highest FLS2-1 steady-state expression levels,although it was not induced by *** selected FmFLS2-1,CrFLS2-2 and CpFLS2-2 to further evaluate their capacity to enhance bacterial resistance using Agrobacterium-mediated transient expression *** FmFLS2-1 and CrFLS2-2,the two proteins from canker-resistant species,conferred stronger Xflg22 responses and reduced canker symptoms in leaves of the susceptible grapefruit *** two citrus genes will be useful resources to enhance PTI and achieve resistance against canker and possibly other bacterial pathogens in susceptible citrus types.

关键词： FLS2 citrus citri

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The Chapman-Richards Distribution and its Relationship to the Generalized beta

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Forest Ecosystems 2019年第3期6卷 219-235页

作者： jeffrey H.Gove Thomas b.Lynch Mark j.Ducey USDA Forest Service Northern Research Station271 Mast Road Durham 03824NHUSA Professor Emeritus Department of Natural Resource Ecology and ManagementOklahoma State UniversityAg Hall Room 008CStillwater 74078OKUSA Department of Natural Resources and the Environment University of New Hampshire114 James Hall Durham 03824NHUSA

background: The Chapman-Richards distribution is developed as a special case of the equilibrium solution to the McKendrick-Von Foerster equation. The Chapman-Richards distribution incorporates the vital rate assumptions of the Chapman-Richards growth function, constant mortality and recruitment into the mathematical form of the distribution. Therefore, unlike 'assumed' distribution models, it is intrinsically linked with the underlying vital rates for the forest area under consideration. Methods: It is shown that the Chapman-Richards distribution can be recast as a subset of the generalized beta distribution of the first kind, a rich family of assumed probability distribution models with known properties. These known properties for the generalized beta are then immediately available for the Chapman-Richards distribution, such as the form of the compatible basal area-size distribution. A simple two-stage procedure is proposed for the estimation of the model parameters and simulation experiments are conducted to validate the procedure for four different possible distribution shapes. Results: The simulations explore the efficacy of the two-stage estimation procedure;these cover the estimation of the growth equation and mortality-recruitment derives from the equilibrium assumption. The parameter estimates are shown to depend on both the sample size and the amount of noise imparted to the synthetic measurements. The results vary somewhat by distribution shape, with the smaller, noisier samples providing less reliable estimates of the vital rates and final distribution forms. Conclusions: The Chapman-Richards distribution in its original form, or recast as a generalized beta form, presents a potentially useful model integrating vital rates and stand diameters into a flexible family of resultant distributions shapes. The data requirements are modest, and parameter estimation is straightforward provided the minimal recommended sample sizes are obtained.

关键词： Diameter distributions Chapman-Richards growth Generalized beta distribution of the first kind Maximum likelihood McKendrick-Von Foerster equation Physiologically structured population model Size-structured distributions

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Recent advances in flexible and stretchable electronics, sensors and power sources

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Science China Chemistry 2012年第5期55卷 718-725页

作者： TOK jeffrey b.-H. Department of Chemical Engineering Stanford University Stanford CA 94305 USA

There has been ongoing keen interest to mold electronic devices into desired shapes and be laid on desired configurable surfaces. In specific, the ability to design materials that can bend, twist, compress and stretch repeatedly, while still able to maintain its full capability as conductors or electrodes, has led to numerous efforts to develop flexible and stretchable (bio)devices that are both technologically challenging and environmentally friendly (e.g. biodegradable). In this review, we highlight several recent significant results that have made impacts toward the field of flexible and stretchable electronics, sensors and power sources.

关键词： organic transistors flexible electronics stretchable electronics electronic skin sensor

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Stable isotope paleohydrology and chemostratigraphy of the Albian Wayan Formation from the wedge-top depozone,North American Western Interior basin

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Science China Earth Sciences 2017年第1期60卷 44-57页

作者： jeffrey b.ROSS Greg A.LUDVIGSON Andreas MOLLER Luis A.GONZALEZ j.D.WALKER Department of Geology University of Kansas Kansas Geological Survey University of Kansas

Understanding of the role of atmospheric moisture and heat transport in the climate system of the Cretaceous greenhouse world represents a major challenge in Earth system science. Stable isotopic paleohydrologic data from mid-Cretaceous paleosols in North America, from paleoequatorial to paleoArctic latitudes, have been used to constrain the oxygen isotope mass balance of the Albian hydrologic cycle. Over the range from 40°-50°N paleolatitude, sideritic paleosols predominate, indicating paleoenvironments with positive precipitation-evaporation （P-E） balances. Local exceptions occur on leeward side of the Sevier Orogen, where calcic paleosols in the wedge-top depozone record paleoenvironments with negative P-E balances in the orographic rain shadow. Stratigraphic sections in the Wayan Formation of Idaho （WF） were sampled from the wedge-top depozone. The units consist of stacked m-scale mudstone paleosols separated by m-scale sandstone-siltstone beds. Sections were sampled for organic carbon isotope profiles, and b-horizons from 6 well-developed paleosols were sampled for detrital zircons to determine maximum depositional ages. The first of these from the WF has produced a U-Pb concordia age of 101.0±1.1 Ma. This same WF section has produced a stratigraphic trend of upwardly decreasing δ18C values ranging from -24‰ upwards to -27‰ VPDb, suggesting correlation to the late Albian C15 C-isotope segment. Pedogenic carbonates from the WF principally consist of micritic calcite, with carbon-oxygen isotope values that array along meteoric calcite lines （MCLs） with δ18O values that range from -9.47‰ up to -8.39‰ VPDb. At approximately 42°N paleolatitude, these MCL values produce calculated paleoprecipitation values of-8.12‰ to -7.04‰ VSMOW, a range that is consistent with the estimates produced from other proxies at the same paleolatitudes across North America. These results indicate that despite the orographic rain shadow effect, the processes of meridional atmospheric moist

关键词： Cretaceous Paleoclimate Wayan Formation Pedogenic carbonates Geochronology

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A note on the estimation of variance for big bAF sampling

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Forest Ecosystems 2020年第4期7卷 819-832页

作者： jeffrey H.Gove Timothy G.Gregoire Mark j.Ducey Thomas b.Lynch USDA Forest Service Northern Research Station271 Mast RoadDurham NH03824USA. School of Forestry&Environmental Studies Yale University360 Prospect StNew Haven CT06511USA. Department of Natural Resources and the Environment University of New Hampshire114 James HallDurham NH03824USA. Professor Emeritus Department of Natural Resource Ecology and ManagementOklahoma State UniversityAg Hall Room 008CStillwater OK74078USA.

background:The double sampling method known as“big bAF sampling”has been advocated as a way to reduce sampling effort while still maintaining a reasonably precise estimate of volume.A well-known method for variance determination,bruce’s method,is customarily used because the volume estimator takes the form of a product of random ***,the genesis of bruce’s method is not known to most foresters who use the method in ***:We establish that the Taylor series approximation known as the Delta method provides a plausible explanation for the origins of bruce’s *** were conducted on two different tree populations to ascertain the similarities of the Delta method to the exact variance of a ***,two alternative estimators for the variance of individual tree volume-basal area ratios,which are part of the estimation process,were compared within the overall variance estimation ***:The simulation results demonstrate that bruce’s method provides a robust method for estimating the variance of inventories conducted with the big bAF *** simulations also demonstrate that the variance of the mean volume-basal area ratios can be computed using either the usual sample variance of the mean or the ratio variance estimators with equal accuracy,which had not been shown previously for big bAF ***:A plausible explanation for the origins of bruce’s method has been set forth both historically and mathematically in the Delta *** most settings,there is evidently no practical difference between applying the exact variance of a product or the Delta method—either can be used.A caution is articulated concerning the aggregation of tree-wise attributes into point-wise summaries in order to test the correlation between the two as a possible indicator of the need for further covariance augmentation.

关键词： bitterlich sampling Delta method Double sampling Forest inventory Horizontal point sampling Variance of a product

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An approximate point-based alternative for the estimation of variance under big bAF sampling

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Forest Ecosystems 2021年第3期8卷 439-457页

作者： Thomas b.Lynch jeffrey H.Gove Timothy G.Gregoire Mark j.Ducey Professor Emeritus Department of Natural Resource Ecology and ManagementOklahoma State UniversityAg Hall Room 008CStillwater 74078OKUSA USDA Forest Service Northern Research Station271 Mast RoadDurham 03824NHUSA Yale School of Environment Yale University360 Prospect StNew Haven 06511CTUSA Department of Natural Resources and the Environment University of New Hampshire114 James HallDurham 03824NHUSA

background:A new variance estimator is derived and tested for big bAF(basal Area Factor)sampling which is a forest inventory system that utilizes bitterlich sampling(point sampling)with two bAF sizes,a small bAF for tree counts and a larger bAF on which tree measurements are made usually including DbHs and heights needed for volume ***:The new estimator is derived using the Delta method from an existing formulation of the big bAF estimator as consisting of three sample *** new formula is compared to existing big bAF estimators including a popular estimator based on bruce’s ***:Several computer simulation studies were conducted comparing the new variance estimator to all known variance estimators for big bAF currently in the forest inventory *** simulations the new estimator performed well and comparably to existing variance ***:A possible advantage of the new estimator is that it does not require the assumption of negligible correlation between basal area counts on the small bAF factor and volume-basal area ratios based on the large bAF factor selection trees,an assumption required by all previous big bAF variance estimation *** this correlation was negligible on the simulation stands used in this study,it is conceivable that the correlation could be significant in some forest types,such as those in which the DbH-height relationship can be affected substantially by density perhaps through *** derived a formula that can be used to estimate the covariance between estimates of mean basal area and the ratio of estimates of mean volume and mean basal *** also mathematically derived expressions for bias in the big bAF estimator that can be used to show the bias approaches zero in large samples on the order of 1n where n is the number of sample points.

关键词： bitterlich sampling Delta method Double sampling Estimator bias Forest inventory Horizontal point sampling Variance of a product Volume basal area ratio Covariance estimation

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Sexual selection on color and behavior within and between cichlid populations： Implications for speciation

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Current Zoology 2012年第3期58卷 475-483页

作者： Michael j.PAUERS jeffrey S.MCKINNON Section of Vertebrate Zoology The Milwaukee Public MuseumMilwaukeeWI 53233USA Department of biology N108 Howell Science ComplexEast Carolina UniversityGreenvilleNC 27858-4353USA

Sexual selection is widely viewed as playing a central role in haplochromine cichlid speciation. Hypothetically, once divergent mate preferences evolve among populations of these fishes, reproductive isolation follows and the populations begin to behave as different species. Various studies have examined patterns of assortative mating among species and sometimes populations, but few have examined variation in directional preferences, especially among populations of the same species. We investi- gated mate choice behavior in two populations of Labeotropheus fueUeborni, a Lake Malawi endemic. We test whether mating preferences between populations are based on the same traits and in the same direction as preferences within populations. We examine the potential contributions of two classes of trait, color patterns and behaviors, to reproductive isolation. When females chose between either two males of their own population, or two from another, female preferences were generally similar （for the female population） across the two contexts. Mate choice patterns differed between （female） populations for a measure of color, but only modestly for male behavior. In a separate experiment we simultaneously offered females a male of their own population and a male from a different population. In these trials, females consistently preferred males from their own population, which were also the males that displayed more frequently than their opponents, but not necessarily those with color traits suggested to be most attractive in the previous experiment. Thus directional preferences for chroma and related aspects of color may be important when females are presented with males of otherwise similar phenotypes, but may play little role in mediating assortative mating among populations with substantially different color patterns. A preference for male behavior could play some role in speciation if males preferentially court same-population females, as we have observed for the populations

关键词： Haplochromine cichlid Sexual selection Speciation Color Labeotropheus

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Female and male visually based mate preferences are consistent with reproductive isolation between populations of the Lake Malawi endemic Labeotropheus fuelleborni

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Current Zoology 2010年第1期56卷 65-72页

作者： Michael j.PAUERS Timothy j.EHLINGER jeffrey S.McKINNON Department of biological Sciences The University of Wisconsin-Milwaukee Division of Natural and Health Sciences Carroll University Department of biology East Carolina University

Sexual selection via female mate choice is thought to have played a key role in the speciation ofhaplochromine cichlids, but a dominant role for visual signals in such processes has lately been called into question. In addition, the possible role of male mating preferences in haplochromine speciation has been little studied. We studied patterns of both female and male mate choice, based exclusively on visual signals, in order to evaluate potential reproductive isolation between two populations of the Lake Malawi haplochromine Labeotropheus fuelleborni. In the first experiment, females were allowed to choose between two males, one from the same population and the other allopatric with respect to the female. Females in this experiment responded more frequently to males from their own population. Similarly, the males in these trials displayed more frequently when presented with females of their own population. In the second experiment, a female was allowed to choose between two males, either both from her own population or both allopatric. In these trials, both males and females from the Katale population interacted significantly more frequently in settings in which all three individuals were from the same population （＂same-population trios＂）, and those from the Chipoka population showed a similar trend. Thus, patterns in both male and female courtship behavior suggest that visual signals contribute to at least incipient reproductive isolation between populations of L. fuelleborni [Current Zoology 56 （ 1 ）： 65-72 2010].

关键词： Cichlid Mate choice Reproductive isolation Sexual selection Speciation

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