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A brief history of neuroscience at the University of British Columbia
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作者 Max S Cynader Heather Amos 《Journal of Translational Neuroscience》 2016年第1期56-59,共4页
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Differing profiles of people diagnosed with acute and chronic hepatitis B virus infection in British Columbia,Canada 被引量:3
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作者 Mawuena Binka Zahid A Butt +13 位作者 Stanley Wong Mei Chong Jane A Buxton Nuria Chapinal Amanda Yu Maria Alvarez Maryam Darvishian Jason Wong Gina McGowan Mikhail Torban Mark Gilbert Mark Tyndall Mel Krajden Naveed Z Janjua 《World Journal of Gastroenterology》 SCIE CAS 2018年第11期1216-1227,共12页
AIM To describe the characteristics of people diagnosed with acute and chronic hepatitis B virus(HBV) infection in British Columbia(BC).METHODS We used data from the BC Hepatitis Testers Cohort(BCHTC),which includes a... AIM To describe the characteristics of people diagnosed with acute and chronic hepatitis B virus(HBV) infection in British Columbia(BC).METHODS We used data from the BC Hepatitis Testers Cohort(BCHTC),which includes all individuals tested for hepatitis C virus(HCV) or human immunodeficiency virus(HIV) or those diagnosed with HBV or active tuberculosis in BC since 1990.These data were integrated with prescription drug,medical visit,hospitalization and mortality data.HBV cases were classified as acute or chronic according to provincial guidelines.We compared characteristics of individuals by HBV infection group(acute,chronic and negative).Factors associated with acute or chronic HBV infection were assessed with multinomial logistic regression models in comparison to the HBV negative group.RESULTS46498 of the 1058056 eligible BC-HTC participants were diagnosed with HBV infection.4.3% of HBV positive individuals were diagnosed with acute HBV infections while 95.7% had chronic infections.Problematic alcohol use,injection drug use,and HIV or HCV co-infection were more common among individuals diagnosed with acute HBV compared to those with chronic infections and HBV negative individuals.In multivariable multinomial logistic regression models,we observed significant associations between acute or chronic HBV diagnosis and being male,age at HBV diagnosis or birth cohort,South and East Asian ethnicity,HCV or HIV infection,and injection drug use.The odds of acute HBV decreased with increasing age among people who inject drugs,while the opposite was true for chronic HBV.Persons with acute HBV were predominantly White(78%) while those with chronic HBV were mostly East Asian(60%).Relative to Whites,East Asians had 12 times greater odds of being diagnosed with chronic HBV infection.These odds increased with increasing socioeconomic deprivation.CONCLUSION Differences in the profiles of people diagnosed with acute and chronic HBV infection necessitate differentiated screening,prevention,care and treatment programs. 展开更多
关键词 HEPATITIS B virus ETHNICITY Drug use ACUTE HEPATITIS B BC HEPATITIS Testers COHORT North America
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Mental health-related healthcare service utilisation and psychotropic drug dispensation trends in British Columbia during COVID-19 pandemic:a population-based study
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作者 Moe Zandy Sylvia El Kurdi +3 位作者 Hasina Samji Geoff McKee Reka Gustafson Kate Smolina 《General Psychiatry》 CAS CSCD 2023年第1期50-57,共8页
Background The impact of the COVID-19 pandemic on the population’s mental health is vital for informing public health policy and decision-making.However,information on mental health-related healthcare service utilisa... Background The impact of the COVID-19 pandemic on the population’s mental health is vital for informing public health policy and decision-making.However,information on mental health-related healthcare service utilisation trends beyond the first year of the pandemic is limited.Aims We examined mental health-related healthcare service utilisation patterns and psychotropic drug dispensations in British Columbia,Canada,during the COVID-19 pandemic compared with the prepandemic period.Methods We conducted a retrospective population-based secondary analysis using administrative health data to capture outpatient physician visits,emergency department visits,hospital admissions and psychotropic drug dispensations.We examined time trends of mental health-related healthcare service utilisation and psychotropic drug dispensations between January to December 2019(prepandemic period)and January 2020 to December 2021(pandemic period).In addition,we calculated age-standardised rates and rate ratios to compare mental health-related healthcare service utilisation before and during the first two years of the COVID-19 pandemic,stratified by year,sex,age and condition.Results By late 2020,except for emergency department visits,utilisation of healthcare services recovered to prepandemic levels.Between 2019 and 2021,the monthly average rate for overall mental health-related outpatient physician visits,emergency department visits and psychotropic drug dispensations increased significantly by 24%,5%and 8%,respectively.Notable and statistically significant increases were observed among 10–14 year-olds(44%in outpatient physician visits,30%in emergency department visits,55%in hospital admissions and 35%in psychotropic drug dispensations)and 15–19 year-olds(45%in outpatient physician visits,14%in emergency department visits,18%in hospital admissions and 34%in psychotropic drug dispensations).Additionally,these increases were more prominent among females than males,with some variation for specific mental health-related conditions.Conclusions The increase in mental health-related healthcare service utilisation and psychotropic drug dispensations during the pandemic likely reflects significant societal consequences of both the pandemic and pandemic management measures.Recovery efforts in British Columbia should consider these findings,especially among the most affected subpopulations,such as adolescents. 展开更多
关键词 service consequences CANADA
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Comparison of carbon-stock changes, eddycovariance carbon fluxes and model estimates in coastal Douglas-fir stands in British Columbia 被引量:1
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作者 Colin J Ferster JA (Tony) Trofymow +2 位作者 Nicholas C Coops Baozhang Chen Thomas Andrew Black 《Forest Ecosystems》 SCIE CAS CSCD 2015年第2期104-122,共19页
Background: The global network of eddy-covariance(EC) flux-towers has improved the understanding of the terrestrial carbon(C) cycle, however, the network has a relatively limited spatial extent compared to forest inve... Background: The global network of eddy-covariance(EC) flux-towers has improved the understanding of the terrestrial carbon(C) cycle, however, the network has a relatively limited spatial extent compared to forest inventory data and plots. Developing methods to use inventory-based and EC flux measurements together with modeling approaches is necessary evaluate forest C dynamics across broad spatial extents.Methods: Changes in C stock change(ΔC) were computed based on repeated measurements of forest inventory plots and compared with separate measurements of cumulative net ecosystem productivity(ΣNEP) over four years(2003 – 2006) for Douglas-fir(Pseudotsuga menziesii var menziesii) dominated regeneration(HDF00), juvenile(HDF88and HDF90) and near-rotation(DF49) aged stands(6, 18, 20, 57 years old in 2006, respectively) in coastal British Columbia. ΔC was determined from forest inventory plot data alone, and in a hybrid approach using inventory data along with litter fall data and published decay equations to determine the change in detrital pools. These ΔC-based estimates were then compared with ΣNEP measured at an eddy-covariance flux-tower(EC-flux) and modelled by the Carbon Budget Model- Canadian Forest Sector(CBM-CFS3) using historic forest inventory and forest disturbance data.Footprint analysis was used with remote sensing, soils and topography data to evaluate how well the inventory plots represented the range of stand conditions within the area of the flux-tower footprint and to spatially scale the plot data to the area of the EC-flux and model based estimates.Results: The closest convergence among methods was for the juvenile stands while the largest divergences were for the regenerating clearcut, followed by the near-rotation stand. At the regenerating clearcut, footprint weighting of CBM-CFS3 ΣNEP increased convergence with EC flux ΣNEP, but not for ΔC. While spatial scaling and footprint weighting did not increase convergence for ΔC, they did provide confidence that the sample plots represented site conditions as measured by the EC tower.Conclusions: Methods to use inventory and EC flux measurements together with modeling approaches are necessary to understand forest C dynamics across broad spatial extents. Each approach has advantages and limitations that need to be considered for investigations at varying spatial and temporal scales. 展开更多
关键词 不列颠哥伦比亚省 模型估计 碳通量 协方差 储量变化 涡度 森林资源清查 格拉斯
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Analysis of Impervious Surface Area, and the Impacts on Soil-Based Agriculture and the Hydrologic Cycle: A Case Study in the Agricultural Land Reserve in Metro Vancouver, British Columbia, Canada 被引量:1
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作者 Ashley Rose Julie E. Wilson Les M. Lavkulich 《Agricultural Sciences》 2017年第8期837-856,共20页
The province of British Columbia, Canada, has established an Agricultural Land Reserve (ALR) to protect the most suitable soil landscapes for agriculture. Increases in population and urbanization have resulted in deve... The province of British Columbia, Canada, has established an Agricultural Land Reserve (ALR) to protect the most suitable soil landscapes for agriculture. Increases in population and urbanization have resulted in development challenges on ALR lands. The Metro Vancouver area is the most productive agricultural area in British Columbia as well as the most rapidly growing urban region. The increase in impervious areas has decreased the amount of arable land for soil-based agriculture and altered the hydrological cycle. Analysis using a combination of aerial imagery and GIS found that impervious areas comprise about 10 percent of the ALR within Metro Vancouver. Farm residences and greenhouses have the largest effect on reducing the soil surface for water infiltration. This decrease in area has negatively influenced the ecosystem heath of the region, as well as, decreasing the amount of agricultural land for soil based agriculture and both surface and groundwater dynamics. 展开更多
关键词 AGRICULTURAL Land Reserve Impervious Surfaces Watershed Health STORMWATER Runoff HYDROLOGY
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Effects of thinning and understory removal on water use efficiency of Pinus massoniana:evidence from photosynthetic capacity and stable carbon isotope analyses
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作者 Ting Wang Qing Xu +4 位作者 Beibei Zhang Deqiang Gao Ying Zhang Jing Jiang Haijun Zuo 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期42-53,共12页
Understanding the relationship between forest management and water use efficiency(WUE)is important for evaluating forest adaptability to climate change.However,the effects of thinning and understory removal on WUE and... Understanding the relationship between forest management and water use efficiency(WUE)is important for evaluating forest adaptability to climate change.However,the effects of thinning and understory removal on WUE and its key controlling processes are not well understood,which limits our comprehension of the physiological mechanisms of various management practices.In this study,four forest management measures(no thinning:NT;understory removal:UR;light thinning:LT;and heavy thinning:HT)were carried out in Pinus massoniana plantations in a subtropical region of China.Photosynthetic capacity and needle stable carbon isotope composition(δ^(13)C)were measured to assess instantaneous water use efficiency(WUE_(inst))and long-term water use efficiency(WUE_(i)).Multiple regression models and structural equation modelling(SEM)identified the effects of soil properties and physiological performances on WUE_(inst)and WUE_(i).The results show that WUE_(inst)values among the four treatments were insignificant.However,compared with the NT stand(35.8μmol·mol^(-1)),WUE_(i)values significantly increased to 41.7μmol·mol^(-1)in the UR,50.1μmol·mol^(-1)in the LT and 46.6μmol·mol^(-1)in HT treatments,largely explained by photosynthetic capacity and soil water content.Understory removal did not change physiological performance(needle water potential and photosynthetic capacity).Thinning increased the net photosynthetic rate(A_n)but not stomatal conductance(g_s)or predawn needle water potential(ψ_(pd)),implying that the improvement in water use efficiency for thinned stands was largely driven by radiation interception than by soil water availability.In general,thinning may be an appropriate management measure to promote P.massoniana WUE to cope with seasonal droughts under future extreme climates. 展开更多
关键词 Stable carbon isotope Water use efficiency THINNING Understory removal Photosynthetic capacity Needle water potential
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Lithium-ion and solvent co-intercalation enhancing the energy density of fluorinated graphene cathode
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作者 Hao Wang Jie Jiang +5 位作者 Pengyu Chen Zhenrui Wu Xiaobin Niu Chuying Ouyang Jian Liu Liping Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期208-215,I0006,共9页
Fluorinated carbons CF_xhold the highest theoretical energy density(e.g.,2180 W h kg^(-1)when x=1)among all cathode materials of lithium primary batteries.However,the low conductivity and severe polarization limit it ... Fluorinated carbons CF_xhold the highest theoretical energy density(e.g.,2180 W h kg^(-1)when x=1)among all cathode materials of lithium primary batteries.However,the low conductivity and severe polarization limit it to achieve its theory.In this study,we design a new electrolyte,namely 1 M LiBF_(4)DMSO:DOL(1:9 vol.),achieving a high energy density in Li/CF_xprimary cells.The DMSO with a small molecular size and high donor number successfully solvates Li^(+)into a defined Li^(+)-solvation structure.Such solvated Li^(+)can intercalate into the large-spacing carbon layers and achieve an improved capacity.Consequently,when discharged to 1.0 V,the CF_(1.12)cathode demonstrates a specific capacity of 1944 m A h g^(-1)with a specific energy density of 3793 W h kg^(-1).This strategy demonstrates that designing the electrolyte is powerful in improving the electrochemical performance of CF_(x) cathode. 展开更多
关键词 Fluorinated carbon Conversion reaction High-energy-density primary battery Li^(+)-solvation structure Solvent co-intercalation
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Effect of coir geotextile and geocell on ephemeral gully erosion in the Mollisol region of Northeast China
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作者 QIN Xijin SUN Yiqiu +4 位作者 ZHANG Yan GUAN Yinghui WU Hailong WANG Xinyu WANG Guangyu 《Journal of Arid Land》 SCIE CSCD 2024年第4期518-530,共13页
The unique geomorphological features and farming methods in the Mollisol region of Northeast China increase water catchment flow and aggravate the erosion of ephemeral gully(EG).Vegetation suffers from rain erosion an... The unique geomorphological features and farming methods in the Mollisol region of Northeast China increase water catchment flow and aggravate the erosion of ephemeral gully(EG).Vegetation suffers from rain erosion and damage during the growth stage,which brings serious problems to the restoration of grass in the early stage.Therefore,effects of coir geotextile and geocell on EG erosion under four confluence intensities were researched in this study.Results of the simulated water discharge erosion test showed that when the confluence strength was less than 30 L/min,geocell and coir geotextile had a good effect on controlling EG erosion,and sediment yield of geocell and coir geotextile was reduced by 25.95%–37.82%and 73.73%–88.96%,respectively.However,when confluence intensity increased to 40 L/min,protective effect of coir geotextile decreased,and sediment yield rate increased sharply by 189.03%.When confluence intensity increased to 50 L/min,the protective effect of coir geotextile was lost.On the other hand,geocell showed that the greater the flow rate,the better the protective effect.In addition,with the increase in confluence intensity,erosion pattern of coir geotextile developed from sheet erosion to intermittent fall and then to completion of main rill,and the protective effect was gradually weakened.In contrast,the protective effect of EG under geocell was gradually enhanced from the continuous rill to the intermittent rill and finally to the intermittent fall.This study shows that coir geotextile and geocell can prevent EG erosion,and the effect of geocell is better than that of coir geotextile on the surface of EG. 展开更多
关键词 GEOCELL coir geotextile ephemeral gully confluence intensity erosion control
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VR-based digital twin for remote monitoring of mining equipment:Architecture and a case study
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作者 Jovana PLAVŠIĆ Ilija MIŠKOVIĆNorman BKeevil 《虚拟现实与智能硬件(中英文)》 EI 2024年第2期100-112,共13页
Background Traditional methods for monitoring mining equipment rely primarily on visual inspections,which are time-consuming,inefficient,and hazardous.This article introduces a novel approach to monitoring mission-cri... Background Traditional methods for monitoring mining equipment rely primarily on visual inspections,which are time-consuming,inefficient,and hazardous.This article introduces a novel approach to monitoring mission-critical systems and services in the mining industry by integrating virtual reality(VR)and digital twin(DT)technologies.VR-based DTs enable remote equipment monitoring,advanced analysis of machine health,enhanced visualization,and improved decision making.Methods This article presents an architecture for VR-based DT development,including the developmental stages,activities,and stakeholders involved.A case study on the condition monitoring of a conveyor belt using real-time synthetic vibration sensor data was conducted using the proposed methodology.The study demonstrated the application of the methodology in remote monitoring and identified the need for further development for implementation in active mining operations.The article also discusses interdisciplinarity,choice of tools,computational resources,time and cost,human involvement,user acceptance,frequency of inspection,multiuser environment,potential risks,and applications beyond the mining industry.Results The findings of this study provide a foundation for future research in the domain of VR-based DTs for remote equipment monitoring and a novel application area for VR in mining. 展开更多
关键词 Virtual reality Digital twin Condition monitoring Mining equipment
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Sexual dimorphism of G protein-coupled receptor signaling in the brain
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作者 Sara Aljoudi Hamdan Hamdan Khaled S.Abd-Elrahman 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第8期1635-1636,共2页
G protein-coupled receptors(GPCRs)represent the most substantial family of membrane receptors that are targeted by U.S.Food and Drug Administration-approved drugs.Much of the preclinical research to understand the pha... G protein-coupled receptors(GPCRs)represent the most substantial family of membrane receptors that are targeted by U.S.Food and Drug Administration-approved drugs.Much of the preclinical research to understand the pharmacology of many membrane receptors including GPCRs is derived from studies in male animal models(Karp and Reavey,2019). 展开更多
关键词 DRUGS CLINICAL TARGETED
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Decoding the inconsistency of six cropland maps in China
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作者 Yifeng Cui Ronggao Liu +6 位作者 Zhichao Li Chao Zhang Xiao-Peng Song Jilin Yang Le Yu Mengxi Chen Jinwei Dong 《The Crop Journal》 SCIE CSCD 2024年第1期281-294,共14页
Accurate cropland information is critical for agricultural planning and production,especially in foodstressed countries like China.Although widely used medium-to-high-resolution satellite-based cropland maps have been... Accurate cropland information is critical for agricultural planning and production,especially in foodstressed countries like China.Although widely used medium-to-high-resolution satellite-based cropland maps have been developed from various remotely sensed data sources over the past few decades,considerable discrepancies exist among these products both in total area and in spatial distribution of croplands,impeding further applications of these datasets.The factors influencing their inconsistency are also unknown.In this study,we evaluated the consistency and accuracy of six cropland maps widely used in China in circa 2020,including three state-of-the-art 10-m products(i.e.,Google Dynamic World,ESRI Land Cover,and ESA WorldCover)and three 30-m ones(i.e.,GLC_FCS30,GlobeLand 30,and CLCD).We also investigated the effects of landscape fragmentation,climate,and agricultural management.Validation using a ground-truth sample revealed that the 10-m-resolution WorldCover provided the highest accuracy(92.3%).These maps collectively overestimated Chinese cropland area by up to 56%.Up to 37%of the land showed spatial inconsistency among the maps,concentrated mainly in mountainous regions and attributed to the varying accuracy of cropland maps,cropland fragmentation and management practices such as irrigation.Our work shed light on the promotion of future cropland mapping efforts,especially in highly inconsistent regions. 展开更多
关键词 Consistency and accuracy 10-and 30 m Cropland mapping Agricultural management China
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Autoimmune liver disease and the Canadian First Nations Aboriginal Communities of British Columbia's Pacific Northwest
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作者 Eric M Yoshida Mark Riley Laura T Arbour 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第23期3625-3627,共3页
Primary biliary cirrhosis (PBC) is a well-known but uncommon chronic liver disease that is presumed to be of autoimmune etiology. Recently, investigations in British Columbia (BC), a province of Canada situated along ... Primary biliary cirrhosis (PBC) is a well-known but uncommon chronic liver disease that is presumed to be of autoimmune etiology. Recently, investigations in British Columbia (BC), a province of Canada situated along the Pacific North-West of North America, have suggested that PBC is not a rare disease amongst BC's Aboriginal (i.e. First Nations) communities. Geographically, BC is adjacent to South East Alaska, an American state that has also reported an increased prevalence of PBC amongst its Aboriginal communities. In this article, the medical evidence supporting a hypothesis of increased risk of PBC amongst BC's First Nations communities is reviewed. Evidence suggesting that autoimmune hepatitis is also more likely amongst BC's First Nations communities is also presented. 展开更多
关键词 自体免疫肝疾病 土著社会 加拿大 哥伦比亚 英国
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Healthcare needs and access in a sample of Chinese young adults in Vancouver, British Columbia: A qualitative analysis
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作者 Christine H.K.Ou Sabrina T.Wong +1 位作者 Jean-Fréderic Levesque Elizabeth Saewyc 《International Journal of Nursing Sciences》 2017年第2期173-178,共6页
Objectives: Immigrants of Chinese ethnicity and young people (between 18 and 30 years of age) are known to access health services less frequently and may be at greater risk for experiencing unmet health needs. The pur... Objectives: Immigrants of Chinese ethnicity and young people (between 18 and 30 years of age) are known to access health services less frequently and may be at greater risk for experiencing unmet health needs. The purpose of this study was to examine the health beliefs, health behaviors, primary care access, and perceived unmet healthcare needs of Chinese young adults.Methods: Semi-structured in-depth interviews were carried out with eight Chinese young adults in Vancouver, Canada. Results: A content analysis revealed that these Chinese young adults experienced unmet healthcare needs, did not have a primary care provider, and did not access preventive services. Cultural factors such as strong family ties, filial piety, and the practice of Traditional Chinese Medicine influenced their health behaviors and healthcare access patterns. Conclusion: Chinese young adults share similar issues with other young adults in relation to not having a primary care provider and accessing preventive care but their health beliefs and practices make their needs for care unique from other young adults. 展开更多
关键词 Chinese young adults IMMIGRANTS Primary healthcare Unmet health needs Health behaviours ACCULTURATION
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Integration of Agriculture and Wildlife Ecosystem Services: A Case Study of Westham Island, British Columbia, Canada
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作者 Yuan Zhang Julie E. Wilson Les M. Lavkulich 《Agricultural Sciences》 2017年第5期409-425,共17页
There is concern regarding the loss of ecosystem goods and services as a result of land use changes such as the expansion and intensification of agricultural activities. Assessments of these interactions require innov... There is concern regarding the loss of ecosystem goods and services as a result of land use changes such as the expansion and intensification of agricultural activities. Assessments of these interactions require innovative analyses that combine qualitative and quantitative economic analyses. The Millennium Ecosystem Assessment framework was applied to a peri-urban region in British Columbia, Canada to assess the effects of the integration of agricultural programs and the maintenance of waterfowl habitat located on the Pacific Flyway. The Delta Farmland & Wildlife Trust, a non-governmental organization, has implemented several activities to enhance ecosystem goods and services by cooperative programs among the agricultural community and wildlife interests. The successful collaborative framework has resulted in enhanced soil quality, increased biodiversity, and the maintenance of valuable agriculture and waterfowl habitat. 展开更多
关键词 ECOSYSTEM Services AGRICULTURE LAND Use Change WILDLIFE HABITAT
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Water, Energy and Nutrient Losses from Food Wastage of Selected Crops in Three Agro-Climatic Zones in British Columbia, Canada
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作者 Ana Reinesch Lewis Fausak +1 位作者 Anne Joseph Les Lavkulich 《Agricultural Sciences》 CAS 2022年第8期947-972,共26页
Food waste is a growing global concern. Data on the factors and magnitude are largely global estimates, thus local studies aid in providing information on the impacts of food waste. Three important agro-climatic zones... Food waste is a growing global concern. Data on the factors and magnitude are largely global estimates, thus local studies aid in providing information on the impacts of food waste. Three important agro-climatic zones in British Columbia and nine common crops, both annual and perennial, were selected to evaluate the environmental and nutritional implications of local food waste. Using Canadian estimates of total food waste, the constituent water, caloric content, protein, vitamin C, phosphorus and potassium wasted by each crop were estimated. Regionally, the total production and losses were the highest in the Lower Fraser Valley which had high production of potatoes and blueberries, followed by the Okanagan, with grapes and apples, and Vancouver Island, with potatoes. Virtual water was estimated by the BC Agriculture Water Calculator and used to assess the soil and climatic factors impacting the local water demand. Although soil texture seemed to influence water demand, the agro-climatic zone was the main factor controlling the water demand and the corresponding amount of water wasted. Dry agro-climatic zones had annual virtual water up to two times higher for the same crop and soil texture. Lower water demand crops, finer soils and more efficient irrigation systems were more congruent with water stress scenarios. Total losses for each region were based on conservative estimates and would have supplied the caloric energy and protein for over 40,000 adults, and vitamin C for over 300,000 adults for one year. Additionally, the total N, P and K wasted accounted for up to 32, 2 and 13 kg/ha respectively for common fertilizers used in British Columbia. This study confirmed the significance of food waste impacts on local water demand, human nutrition and soil management based on regional data for representative crops. 展开更多
关键词 Food Loss Food Waste Crop Water Demand Virtual Water NUTRITION
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Interaction of Trembling Aspen and Lodgepole Pine in a Young Sub-Boreal Mixedwood Stand in Central British Columbia
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作者 Amalesh Dhar Jian R. Wang Christopher D. B. Hawkins 《Open Journal of Forestry》 2015年第2期129-138,共10页
Strategies for managing mixed broadleaf-conifer stands in British Columbia (BC) have been under review in recent years as the benefits of mixedwood management have been recognized. More has been learned about the role... Strategies for managing mixed broadleaf-conifer stands in British Columbia (BC) have been under review in recent years as the benefits of mixedwood management have been recognized. More has been learned about the role of broadleaves in forest ecosystems however ecosystem-specific knowledge about the competitive interactions between mixed broadleaf-conifer stands is still scarce. Therefore a competitive interactions study was conducted to facilitate ecosystem-specific management for lodgepole pine (Pinus contorta Dougl. Ex Loud. Var. latifolia Engelm.) and trembling aspen (Populus tremuloides Michx.) in the sub-boreal spruce (SBS) zone of central BC. The experiment was a completely randomized block design with six different aspen densities replicated three times. Each replicate was sampled three times between ages 14 to 19 years. Pine diameter and height growth were influenced by aspen density. Our current quantitative findings suggest that lodgepole pine growth was not impacted when growing with aspen densities up to 2500 stems ha-1. Considering free growing (FTG) and not free growing (NFTG) pine at the time of trial establishment, an insignificant difference was found for DBH, height and crown volume responses. Leaf area index (LAI) and diffuse non-interceptance (DIFN) radiation were also not significantly different between FTG or NFTG trees suggesting our results exceed the current BC’s free growing standard. Further work is recommended to determine whether or not the current free growing standards are appropriate for producing the desired crop outcome. 展开更多
关键词 COMPETITIVE NEIGHBOURHOODS Free Growing Leaf Area Index Mixedwood Management Vegetation
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Disturbance Legacy on Soil Carbon Stocks and Stability within a Coastal Temperate Forest of Southwestern British Columbia, Canada
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作者 Camille E. Defrenne Julie E. Wilson +1 位作者 Suzanne W. Simard Les M. Lavkulich 《Open Journal of Forestry》 2016年第5期305-323,共19页
Although it has been recognized that soils play a critical role in carbon storage and that coastal temperate forests have considerable potential to sequester soil organic carbon (SOC), studies related to SOC stocks an... Although it has been recognized that soils play a critical role in carbon storage and that coastal temperate forests have considerable potential to sequester soil organic carbon (SOC), studies related to SOC stocks and stability are scarce in these ecosystems. Forest disturbances may leave legacies on SOC properties and may further compromise SOC storage capacity of these ecosystems. In the Pacific Spirit Regional Park of southwestern British Columbia, we compared SOC stocks and stability among three second-growth forests that have been affected by disturbances of different magnitudes. We collected data on soil chemical and physical properties to estimate SOC content and assess SOC stability. We found that SOC stocks in the forest characterized by low magnitude disturbance were greater than those of the forest characterized by high magnitude disturbance (8.2 ± 1.3 kg·Cm<sup>-2</sup> versus 5.3 ± 0.1 kg·Cm<sup>-2</sup> to 30 cm depth). SOC was less stable in the highly disturbed forest and subsequent vegetation changes might have further reduced SOC stability. Our results provide insight into the role of disturbance history in the current SOC storage capacity of coastal temperate rainforests of British Columbia. 展开更多
关键词 Soil Carbon Coastal Forest Disturbances History Carbon Storage Carbon Stocks
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Effects of Aggregate Extraction on Water Storage in the Pepin Creek Watershed, British Columbia, Canada
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作者 Yining Wang Julie E. Wilson +1 位作者 Drew Brayshaw Les M. Lavkulich 《Natural Resources》 2017年第7期461-477,共17页
Aggregate extraction in the Lower Fraser Valley of British Columbia, Canada, has affected the soil water storage of the Pepin Creek watershed. Although local government has set regulations for aggregate extraction pro... Aggregate extraction in the Lower Fraser Valley of British Columbia, Canada, has affected the soil water storage of the Pepin Creek watershed. Although local government has set regulations for aggregate extraction projects to avoid negative environmental impacts, the gradual loss of soil materials and associated changes in vegetative cover has led to an alteration of the water balance within the watershed, which may affect surface or groundwater levels, and aquatic habitats. The study assessed the effects of aggregate extraction on the water storage of the Pepin Creek watershed and estimated that 25% of the surface area of the Canadian portion of the watershed has been affected by aggregate mining with an estimated loss of water storage of 10%. Evapotranspiration has decreased as a result of the removal of the vegetative cover. Precipitation has remained relatively constant over the study period but the annual discharge measured at Pepin Creek has decreased. Recommendations for enhancing environmental monitoring to better measure and understand ecological functions of the watershed during aggregate extraction are provided. 展开更多
关键词 Soil WATER STORAGE AGGREGATE EXTRACTION WATER Balance WATERSHED STORAGE
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A Historical Review of the Development of Women’s Higher Education in China (1908-2020): Stages, Explanations, and Trends
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作者 TIAN Fen ZHENG Yaqian Ray Taheri 《Journal of Sociology Study》 2024年第1期39-53,共15页
The development of women’s higher education in China can be divided into four stages:emergence(1908-1948);foundation(1949-1976);accelerating development(1977-2008);and the qualitative leap(2009-2020).This work consid... The development of women’s higher education in China can be divided into four stages:emergence(1908-1948);foundation(1949-1976);accelerating development(1977-2008);and the qualitative leap(2009-2020).This work considers the principal institutional mechanisms that contributed to this development.First,flexibly planned parenthood gradually promoted gender equality and openness in society facilitated by systematic“awards,grants,and loans”initiatives to support women’s higher education economically.Second,compulsory education ensured that left-out and migrant children had access to higher education.Third,effective connectivity across different education types bridged education gaps between those with different levels of education.Fourth,China made great efforts to invite and integrate international experiences that promoted the development of women’s higher education.Looking beyond these achievements,we also discuss the future trends of women’s higher education in China. 展开更多
关键词 Chinese higher education women’s higher education educational equity development process
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Seismology in the Light of Fundamental Sciences
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作者 Bychkov Serguei 《Open Journal of Earthquake Research》 2024年第1期84-112,共29页
According to the definition, seismology is a science that studies the processes and causes of seismic phenomena and the structure of the Earth, i.e. a scientific discipline that studies the movement of blocks of rocks... According to the definition, seismology is a science that studies the processes and causes of seismic phenomena and the structure of the Earth, i.e. a scientific discipline that studies the movement of blocks of rocks of the Earth’s crust and mantle and related phenomena. Seismology conducts research in the following areas and is designed to scientifically explain two main issues: 1) Study of the nature of seismic phenomena and the internal structure of the Earth. Why, how and where do seismic impacts occur? 2) Protecting humanity from the catastrophic consequences of seismic events. Is it possible to predict seismic impacts? Like any other scientific discipline, seismology is obliged to follow the laws of science and its fundamental principles. This article is devoted to the description of violations of the fundamental laws of science committed by seismologists in the study of seismic processes and raises the question of compliance of the stated research directions with the current level of development of sciences. Answering point No. 1, regarding the structure of the Earth, it is possible to recognize some successes of seismology, which nevertheless cause great doubts in the scientific community of geophysicists, because if the stratigraphic data of ultra-deep wells often refute [1] the conclusions made by seismologists on the structure of the Earth’s crust at shallow depth, then to assert something unambiguously about the structure of the mantle and at the present stage, seismology cannot. Answering the main questions of seismology, why seismic phenomena occur, and how earthquake energy is formed, seismologists have not had, and have not. Answering point No. 2, we can confidently say that in the matter of forecasting seismic phenomena, seismology has not advanced one iota over the past century, and as seismologists have been confused in the search for earthquake prediction algorithms, they are also confused without any hope of success. All that modern seismology can “boast” is the theory of Elastic recoil [2], the absurdity of which does not cause any doubt among the progressive part of geophysicists. But, the fact that most of the leading scientists-seismologists continue to piously believe the conclusions of the Elastic Recoil theory puts seismology in a humiliating position, because Mr. Reid’s theory is the clearest example of a false theory based on scientific incompetence of scientists, a model of brazen violation of the fundamental laws of science and the foundation of false and ignorant conclusions. Based on the results achieved, or rather on their absence, we regret to draw a sad conclusion: modern seismology is in the deepest decline, the cause of which is the incompetence of researchers as a result of their catastrophically low level of academic training, who stuff the scientific community with scientific geophysical rubbish, breeding similar ignoramuses in seismology. We understand that by asserting this, we offend most seismologists, but it is impossible to continue to tolerate this state of affairs in geophysics, because: “Amicus plato, sed magis amica est veritas.” Obviously, the time has come for a new meteorologist, Alfred Wagener [3], who will come and teach seismologists not to guess on coffee grounds, but to investigate seismic processes using the fundamental laws of science. In this article, we not only investigate the reasons for the unsatisfactory state of affairs in seismology, but also give our answers to the questions, of why earthquakes occur and how seismic energy is formed. 展开更多
关键词 SEISMOLOGY EARTHQUAKE Fundamental Laws of Science
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