检索结果-南通市图书馆

Forest Ecosystems 2024年第2期11卷 140-141页

作者： Klaus von Gadow Faculty of Forestry and Forest Ecology Georg-August-University GöttingenBüsgenweg 5D-37077GöttingenGermany Department of Forestry and Wood Science Faculty of AgriSciencesStellenbosch UniversityStellenbosch Private Bag X1Stellenbosch7602South Africa

In a world of Google and AI, developing an encyclopedic coverage of a theme that is of great interest to biologists, social scientists, politicians and environmental managers, is a daunting challenge. Wattles is a book that presents new knowledge, makes interesting reading, and has the potential to stimulate research in a variety of disciplines. We learn that Acacia, commonly known as the wattles or acacias, is a genus of shrubs and trees comprising 1,083 species of which 417 are known to have been introduced to areas outside their native range. We are surprised to read that Australian acacias are found almost everywhere, in virtually all terrestrial habitats, including woodlands, grasslands, alpine settings,rainforests, coastal dunes and deserts, causing major environmental and socio-economic changes in the invaded regions. Until recently, Acacia comprised a group of plant species native to Africa, South America and Australasia, but the name is now reserved for species predominantly from Australia, including some from Southeast Asia. The genus name Acacia is Neo-Latin, and refers to a preparation extracted from the leaves and fruit pods of Vachellia nilotica, the original type of the genus.

关键词： Richardson outside Latin

Grouping tree species to estimate basal area increment in temperate multispecies forests in Durango,Mexico

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2024年第1期11卷 1-13页

作者： Jaime Roberto Padilla-Martínez Carola Paul Kai Husmann Jose Javier Corral-Rivas Klaus von Gadow Department of Forest Economics and Sustainable Land-use Planning Faculty of Forest Sciences and Forest EcologyUniversity of GottingenBüsgenweg 137077GottingenGermany Facultad de Ciencias Forestales Universidad Juarez del Estado de DurangoRío Papaloapan y Boulevard Durango S/N34120DurangoMexico Faculty of Forestry and Forest Ecology Georg-August-UniversitatBüsgenweg 537077GottingenGermany Department of Forestry and Wood Science Faculty of AgriSciencesStellenbosch UniversityStellenbosch Private Bag X1Stellenbosch7602South Africa

Multispecies forests have received increased scientific attention,driven by the hypothesis that biodiversity improves ecological resilience.However,a greater species diversity presents challenges for forest management and research.Our study aims to develop basal area growth models for tree species cohorts.The analysis is based on a dataset of 423 permanent plots(2,500 m^(2))located in temperate forests in Durango,Mexico.First,we define tree species cohorts based on individual and neighborhood-based variables using a combination of principal component and cluster analyses.Then,we estimate the basal area increment of each cohort through the generalized additive model to describe the effect of tree size,competition,stand density and site quality.The principal component and cluster analyses assign a total of 37 tree species to eight cohorts that differed primarily with regard to the distribution of tree size and vertical position within the community.The generalized additive models provide satisfactory estimates of tree growth for the species cohorts,explaining between 19 and 53 percent of the total variation of basal area increment,and highlight the following results:i)most cohorts show a"rise-and-fall"effect of tree size on tree growth;ii)surprisingly,the competition index"basal area of larger trees"had showed a positive effect in four of the eight cohorts;iii)stand density had a negative effect on basal area increment,though the effect was minor in medium-and high-density stands,and iv)basal area growth was positively correlated with site quality except for an oak cohort.The developed species cohorts and growth models provide insight into their particular ecological features and growth patterns that may support the development of sustainable management strategies for temperate multispecies forests.

关键词： Temperate multispecies forests Cluster analysis Basal area increment Generalized additive models

New indices to balanceα-diversity against tree size inequality

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2024年第1期35卷 229-237页

作者： Li Zhang Brady K.Quinn Cang Hui Meng Lian Johan Gielis Jie Gao Peijian Shi College of Ecology and Environment Bamboo Research InstituteNanjing Forestry University159 Longpan RoadNanjing 210037People’s Republic of China Fisheries and Oceans Canada Andrews Biological Station125 Marine Science DriveSt.AndrewsNB E5B 0E4Canada Department of Mathematical Sciences Centre for Invasion BiologyStellenbosch UniversityMatieland 7602South Africa Mathematical and Physical Biosciences African Institute for Mathematical SciencesCape Town 7945South Africa Department of Biosciences Engineering University of AntwerpB-2020 AntwerpBelgium College of Life Science Xinjiang Normal University102 Xinyi RoadUrumqi 830054People’s Republic of China

The number and composition of species in a community can be quantified withα-diversity indices,including species richness(R),Simpson’s index(D),and the Shannon-Wiener index(H΄).In forest communities,there are large variations in tree size among species and individu-als of the same species,which result in differences in eco-logical processes and ecosystem functions.However,tree size inequality(TSI)has been largely neglected in studies using the available diversity indices.The TSI in the diameter at breast height(DBH)data for each of 99920 m×20 m forest census quadrats was quantified using the Gini index(GI),a measure of the inequality of size distribution.The generalized performance equation was used to describe the rotated and right-shifted Lorenz curve of the cumulative proportion of DBH and the cumulative proportion of number of trees per quadrat.We also examined the relationships ofα-diversity indices with the GI using correlation tests.The generalized performance equation effectively described the rotated and right-shifted Lorenz curve of DBH distributions,with most root-mean-square errors(990 out of 999 quadrats)being<0.0030.There were significant positive correlations between each of threeα-diversity indices(i.e.,R,D,and H’)and the GI.Nevertheless,the total abundance of trees in each quadrat did not significantly influence the GI.This means that the TSI increased with increasing spe-cies diversity.Thus,two new indices are proposed that can balanceα-diversity against the extent of TSI in the com-munity:(1−GI)×D,and(1−GI)×H’.These new indices were significantly correlated with the original D and H΄,and did not increase the extent of variation within each group of indices.This study presents a useful tool for quantifying both species diversity and the variation in tree sizes in forest communities,especially in the face of cumulative species loss under global climate change.

关键词： Diameter at breast height(DBH) Gini index Shannon-Wiener index Simpson’s index Quadrat Tree size

Symptom presentation and evolution in the first 48 hours after injury are associated with return to play after concussion in elite Rugby Union

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2024年第3期13卷 387-397页

作者： Ross Tucker Matt Cross Keith Stokes Lindsay Starling Rosy Hyman Simon Kemp Stephen West Martin Raftery Eanna Falvey James Brown Institute of Sport and Exercise Medicine(ISEM) Department of ExerciseUniversity of StellenboschTygerberg 7505South Africa World Rugby Ltd. Dublin D02 AE93Ireland Premiership Rugby London SW1V 1PXUK Centre for Health and Injury and Illness Prevention in SportUniversity of BathClaverton Down BA27AYUK UK Collaborating Centre on Injury and Illness Prevention in Sport(UKCCIIS) University of BathClaverton Down BA27AYUK Rugby Football Union London TW27BAUK London School of Tropical Medicine London WC1E 7HTUK Sport Injury Prevention Research Centre Faculty of KinesiologyUniversity of CalgaryCalgary T2N 1N4Canada Department of Medicine School of Medicine and HealthUniversity College CorkCork T12 EC8PIreland Carnegie Applied Rugby Research(CARR)centre Carnegie School of SportLeeds Beckett UniversityLeeds LS63QSUK

Background:Return to play(RTP)in elite rugby is managed using a 6-stage graduated RTP protocol,which can result in clearance to play within 1 week of injury.We aimed to explore how symptom,cognitive,and balance presentation and evolution during concussion screens 2 h(head injury assessment(HIA2)and 48 h(HIA3)after injury were associated with time to RTP)to identify whether a more conservative graduated RTP may be appropriate.Methods:A retrospective cohort study was conducted in 380 concussed rugby players from elite men’s rugby over 3 consecutive seasons.Players were classified as shorter or longer returns,depending on whether RTP occurred within 7 days(allowing them to be considered to play the match 1 week after injury)or longer than 8 days,respectively.Symptom,cognitive,and balance performance during screens was assessed relative to baseline(normal or abnormal)and to the preceding screen(improving or worsening).Associations between sub-test abnormalities and RTP time were explored using odds ratios(OR,longer vs.shorter).Median day absence was compared between players with abnormal or worsening results and those whose results were normal or improving.Results:Abnormal symptom results during screens 2 h and 48 h after concussion were associated with longer return time(HIA2:OR=2.21,95%confidence interval(95%CI):1.39-3.50;HIA3:OR=3.30,95%CI:1.89-5.75).Worsening symptom number or severity from the time of injury to 2 h and 48 h post-injury was associated with longer return(HIA2:OR=2.49,95%CI:1.36-4.58;HIA3:OR=3.34,95%CI:1.10-10.15).Median days absence was greater in players with abnormal symptom results at both HIA2 and HIA3.Cognitive and balance performance were not associated with longer return and did not affect median days absence.Conclusion:Symptom presentation and evolution within 48 h of concussion were associated with longer RTP times.This may guide a more conservative approach to RTP,while still adhering to individualized concussion management principles.

关键词： Brain injury Concussion management General return to play Medical management

Antimicrobial peptide gene expression and the microbiome in Black Soldier Fly

在线全文

学校读者我要写书评

暂无评论

Insect Science 2023年第4期30卷 1017-1021页

作者： Clint Rhode Matthew P.Greenwood Department of Genetics Stellenbosch UniversityStellenboschSouth Africa

Dear Editor,The black soldier fly(BSF)(Hermetia illucens Linnaeus,1758)is an important insect in the sustainable agriculture sector that has attracted much interest over the last few years.The larvae of this species reduce agricultural waste and convert it into usable biomass that can be reintroduced into food production value chains,creating self-sustained and sanitized systems.The nutritional profile of these larvae is comparable to fishmeal and soy,which has been conventionally used in animal feeds,and other secondary products have also been retrieved,for example,chitin,fertilizers,and biofuels.

关键词： sustained chains convert

Smoke Alarms for Informal Settlements: Monitoring and Challenges from a Large‑Scale Community Rollout in Cape Town, South Africa

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2022年第6期13卷 936-947页

作者： Robyn Pharoah Patricia Zweig Richard Walls Rodney Eksteen Research Alliance for Disaster and Risk Reduction(RADAR) Stellenbosch UniversityStellenbosch 7602South Africa Fire Engineering Research Unit(FireSUN) Stellenbosch UniversityStellenbosch 7602South Africa College of Engineering Architecture and TechnologyOklahoma State UniversityStillwaterOK 74078USA

This article presents the findings of a pilot project to test the large-scale rollout of smoke alarms in an informal community in Cape Town, South Africa. The work provides novel insight into the effectiveness and challenges associated with using smoke detectors in low-income communities. Technical details and detector considerations are also provided that will assist in enhancing future interventions.The project installed 1200 smoke detection devices in TRA informal settlement in the suburb of Wallacedene, in the City of Cape Town, and monitored their effectiveness for a period of 12 months. The monitoring showed that there were 11 real activations, where the presence of the devices likely saved lives and homes. The project also identified a series of challenges, especially in relation to nuisance alarms,where everyday household emissions, dust, and insect ingress caused false alarms, leading some participants to uninstall devices. The findings of the pilot study suggest that although smoke detectors could provide a valuable tool for reducing the frequency and impact of informal settlement fires in South Africa and elsewhere, they need to be adapted to meet the specific needs and conditions encountered in informal dwellings. Modifications, such as adjusting device sensitivity,preventing dust and insect ingress and tailoring devices to everyday conditions, will be essential to make smoke alarms more suitable and effective in the future. Smoke alarms could become an important component of low-income community fire safety if such challenges can be addressed.

关键词： Fire safety Informal dwellings Smoke alarms South Africa

A novel stochastic modeling framework for coal production and logistics through options pricing analysis

在线全文

学校读者我要写书评

暂无评论

Financial Innovation 2023年第1期9卷 1430-1448页

作者： Mesias Alfeus James Collins Department of Statistics and Actuarial Science University of StellenboschStellenboschSouth Africa INSEAD Asia Campus SingaporeSingapore

We propose a novel stochastic modeling framework for coal production and logistics using option pricing theory.The problem of valuing the inherent real optionality a coal producer has when mining and processing thermal coal is modelled as pricing spread options of three assets under the stochastic volatility model.We derive a three-dimensional Fast Fourier Transform(“FFT”)lower bound approximation to value the inherent real optionality and for robustness check,we compare the semi-analytical pricing accuracy with the Monte Carlo simulation.Model parameters are estimated from the historical monthly data,and stochastic volatility parameters are obtained by matching the Kurtosis of the low-ash diff data to the Kurtosis of the stochastic volatility process which is assumed to follow Cox–Ingersoll–Ross(“CIR”)model.

关键词： Stochastic volatility Real option analysis Fast Fourier transform method Coal Monte-Carlo Closed-form solution

Social Meanings of Attempted Suicide of Men in Bangladesh

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fudan Journal of the Humanities and Social Sciences 2022年第4期15卷 553-571页

作者： Anisur Rahman Khan Sipho Dlamini Kopano Ratele Department of Sociology East West UniversityDhaka1212Bangladesh Department of Psychology University of JohannesburgJohannesburgSouth Africa Centre for Critical and Creative Thought Stellenbosch UniversityStellenboschSouth Africa

Émile Durkheim’s Le Suicide(1897/2005)paved the way for the development of the sociology of suicide.However,Durkheim’s positivistic approach in studying suicide was trenchantly challenged by,amongst others,Jack Douglas,who,in Social Meanings of Suicide(1968),advocated extricating the social meanings of suicide from the interpretive tradition of social research.Drawing on Douglas’approach to the sociology of suicide,this paper reports and reflects on part of a study conducted across several rural areas of Jhenaidah,an area in Bangladesh highly affected by suicide,with 17 males who have attempted suicide.The responses of the participants were interpreted with a view to understanding the social meanings associated with their suicide attempts.Although there was a diversity of individual experiences among the participants with regard to suicide attempts,the paper synthesises these and reflects on three themes which most closely represent the commonalities of experience of the 17 men,namely:(i)inability to provide;(ii)intimate relationship stress;and(iii)loss of social status.In conclusion,the paper contributes to understanding suicide attempts by men as social meaningfully events,delineating the roles and complexities associated with constructions of masculine identities.

关键词： Suicide attempt Men Masculinity Social meaning Sociology of suicide

Crop type mapping using LiDAR,Sentinel-2 and aerial imagery with machine learning algorithms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2021年第2期24卷 215-227,I0003页

作者： Adriaan Jacobus Prins Adriaan Van Niekerk Department of Geography&Environmental Studies Stellenbosch UniversityStellenboschSouth Africa

LiDAR data are becoming increasingly available,which has opened up many new applications.One such application is crop type mapping.Accurate crop type maps are critical for monitoring water use,estimating harvests and in precision agriculture.The traditional approach to obtaining maps of cultivated fields is by manually digitizing the fields from satellite or aerial imagery and then assigning crop type labels to each field-often informed by data collected during ground and aerial surveys.However,manual digitizing and labeling is time-consuming,expensive and subject to human error.Automated remote sensing methods is a cost-effective alternative,with machine learning gaining popularity for classifying crop types.This study evaluated the use of LiDAR data,Sentinel-2 imagery,aerial imagery and machine learning for differentiating five crop types in an intensively cultivated area.Different combinations of the three datasets were evaluated along with ten machine learning.The classification results were interpreted by comparing overall accuracies,kappa,standard deviation and f-score.It was found that LiDAR data successfully differentiated between different crop types,with XGBoost providing the highest overall accuracy of 87.8%.Furthermore,the crop type maps produced using the LiDAR data were in general agreement with those obtained by using Sentinel-2 data,with LiDAR obtaining a mean overall accuracy of 84.3%and Sentinel-2 a mean overall accuracy of 83.6%.However,the combination of all three datasets proved to be the most effective at differentiating between the crop types,with RF providing the highest overall accuracy of 94.4%.These findings provide a foundation for selecting the appropriate combination of remotely sensed data sources and machine learning algorithms for operational crop type mapping.

关键词： LiDAR multispectral imagery sentinel-2 machine learning crop type classification per-pixel classification

Consensus-based dispatch optimization of a microgrid considering meta-heuristic-based demand response scheduling and network packet loss characterization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

能源与人工智能(英文)

能源与人工智能(英文) 2023年第1期11卷 71-89页

作者： Ali M.Jasim Basil H.Jasim Soheil Mohseni Alan C.Brent Electrical Engineering Department University of BasrahBasrah61001Iraq Department of Communications Engineering Iraq University CollegeBasrahIraq Sustainable Energy Systems Wellington Faculty of EngineeringVictoria University of WellingtonWellington6140New Zealand Department of Industrial Engineering and the Centre for Renewable and Sustainable Energy Studies Stellenbosch UniversityStellenbosch7600South Africa

The uncertainty inherent in power load forecasts represents a major factor in the mismatches between supply and demand in renewables-rich electricity networks, which consequently increases the energy bills and curtailed generation. As the transition to a power grid founded on the so-called grid-of-grids becomes more evident, the need for distributed control algorithms capable of handling computationally challenging problems in the energy sector does so as well. In this light, the consensus-based distributed algorithm has recently been shown to provide an effective platform for solving the complex energy management problem in microgrids. More specifically, in a microgrid context, the consensus-based distributed algorithm requires reliable information exchange with customers to achieve convergence. However, packet losses remain an important issue, which can potentially result in the failure of the overall system. In this setting, this paper introduces a novel method to effectively characterize such packet losses during information exchange between the customers and the microgrid operator, whilst solving the microgrid scheduling optimization problem for a multi-agent-based microgrid. More specifically, the proposed framework leverages the virulence optimization algorithm and the earth-worm optimization algorithm to optimally shift the energy consumption during peak periods to lower-priced off-peak hours. The effectiveness of the proposed method in minimizing the overall active power mismatches in the presence of packet losses has also been demonstrated based on benchmarking the results against the business-as-usual iterative scheduling algorithm. Also, the robustness of the overall meta-heuristic- and multi-agent-based method in producing optimal results is confirmed based on comparing the results obtained by several well-established meta-heuristic optimization algorithms, including the binary particle swarm optimization, the genetic algorithm, and the cuckoo search optimization.

关键词： Demand-side management Optimal scheduling Microgrids Distribution generation Consensus algorithm Meta-heuristics