期刊文献+
共找到70,979篇文章
< 1 2 250 >
每页显示 20 50 100
Methodology and Equations of Mineral Production Forecast<br>—Part I. Crude Oil in the UK and Gold in Nevada, USA. Prediction of Late Stages of Production 被引量:1
1
作者 Sergio Pérez Rodríguez 《Open Journal of Geology》 2013年第5期352-360,共9页
The equations of mineral production forecast link the change in time of mineral reserves with the production and the ratio of reserves to production. These equations allow us to model the development of the mineral re... The equations of mineral production forecast link the change in time of mineral reserves with the production and the ratio of reserves to production. These equations allow us to model the development of the mineral resources evaluated at any scale. Probabilistic bidimensional charts made from montecarlo simulations provide intervals of confidence for the forecasts. The set of equations is devised and presented for a variety of applications to the oil and gas industry, as well to the production of any other mineral resource, either metals or non metals, whose ore deposit volumes and production might be quantified. The cases studied in the UK and USA are at late stages of production, periods for what the equations are most suitable to be applied without further adjustments. Experimental design allows the diagnosis of the likely values of the variables pertaining to the equations, in order to achieve the results provided by conventional production forecasts or to explore other scenarios of investigation. The method can be practical to evaluate commitments of production of mineral resources with time, to support strategic plans for companies, corporations, countries or regions based on those evaluations, for the screening and ranking of mineral assets based on their production potential and many other tasks where the prediction of future volumes of mineral production is required. 展开更多
关键词 MINERAL Mining Oil Gas MONTECARLO Simulation
下载PDF
Characterization and Propagation of Historical and Projected Droughts in the Umatilla River Basin, Oregon, USA 被引量:1
2
作者 Sudip GAUTAM Alok SAMANTARAY +1 位作者 Meghna BABBAR-SEBENS Meenu RAMADAS 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第2期247-262,I0020-I0028,共25页
Climate change is expected to have long-term impacts on drought and wildfire risks in Oregon as summers continue to become warmer and drier. This paper investigates the projected changes in drought characteristics and... Climate change is expected to have long-term impacts on drought and wildfire risks in Oregon as summers continue to become warmer and drier. This paper investigates the projected changes in drought characteristics and drought propagation in the Umatilla River Basin in northeastern Oregon for mid-century(2030–2059) and late-century(2070–2099) climate scenarios. Drought characteristics for projected climates were determined using downscaled CMIP5 climate datasets from ten climate models and Soil and Water Assessment Tool to simulate effects on hydrologic processes. Short-term(three months) drought characteristics(frequency, duration, and severity) were analyzed using four drought indices, including the Standardized Precipitation Index(SPI-3), Standardized Precipitation-Evapotranspiration Index(SPEI-3), Standardized Streamflow Index(SSI-3), and the Standardized Soil Moisture Index(SSMI-3). Results indicate that short-term meteorological droughts are projected to become more prevalent, with up to a 20% increase in the frequency of SPI-3drought events. Short-term hydrological droughts are projected to become more frequent(average increase of 11% in frequency of SSI-3 drought events), more severe, and longer in duration(average increase of 8% for short-term droughts).Similarly, short-term agricultural droughts are projected to become more frequent(average increase of 28% in frequency of SSMI-3 drought events) but slightly shorter in duration(average decrease of 4%) in the future. Historically, drought propagation time from meteorological to hydrological drought is shorter than from meteorological to agricultural drought in most sub-basins. For the projected climate scenarios, the decrease in drought propagation time will likely stress the timing and capacity of water supply in the basin for irrigation and other uses. 展开更多
关键词 Umatilla DROUGHT SPI SPEI SSI SSMI
下载PDF
Astrocytic calcium waves:unveiling their roles in sleep and arousal modulation
3
作者 Erxi Wu Dan Qi +1 位作者 Damir Nizamutdinov Jason H.Huang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第5期984-987,共4页
Neuron-astrocyte interactions are vital for the brain’s connectome.Understanding astrocyte activities is crucial for comprehending the complex neural network,particularly the population-level functions of neurons in ... Neuron-astrocyte interactions are vital for the brain’s connectome.Understanding astrocyte activities is crucial for comprehending the complex neural network,particularly the population-level functions of neurons in different cortical states and associated behaviors in mammals.Studies on animal sleep and wakefulness have revealed distinct cortical synchrony patterns between neurons.Astrocytes,outnumbering neurons by nearly fivefold,support and regulate neuronal and synaptic function.Recent research on astrocyte activation during cortical state transitions has emphasized the influence of norepinephrine as a neurotransmitter and calcium waves as key components of ion channel signaling.This summary focuses on a few recent studies investigating astrocyte-neuron interactions in mouse models during sleep,wakefulness,and arousal levels,exploring the involvement of noradrenaline signaling,ion channels,and glutamatergic signaling in different cortical states.These findings highlight the significant impact of astrocytes on large-scale neuronal networks,influencing brain activity and responsiveness.Targeting astrocytic signaling pathways shows promise for treating sleep disorders and arousal dysregulation.More research is needed to understand astrocytic calcium signaling in different brain regions and its implications for dysregulated brain states,requiring future human studies to comprehensively investigate neuron-astrocyte interactions and pave the way for therapeutic interventions in sleep-and arousal-related disorders. 展开更多
关键词 AROUSAL ASTROCYTE calcium waves locus coeruleus neuron-astrocyte interaction NOREPINEPHRINE SLEEP WAKEFULNESS
下载PDF
Using a New Glacial History Paradigm and Bald Eagle Through Valley Topographic Map Evidence to Determine Central Pennsylvania’s Geomorphic History, USA
4
作者 Eric Clausen 《Open Journal of Geology》 CAS 2024年第9期880-899,共20页
A new glacial history paradigm that describes huge and prolonged southwest-oriented meltwater floods flowing along the rising rim of a deep “hole” (which a large continental icesheet created and occupied) is used to... A new glacial history paradigm that describes huge and prolonged southwest-oriented meltwater floods flowing along the rising rim of a deep “hole” (which a large continental icesheet created and occupied) is used to explain previously unexplained or poorly explained central Pennsylvania Bald Eagle through valley region topographic map evidence. Pennsylvania’s Bald Eagle through valley as defined here extends in a northeast direction from near Altoona to near Williamsport along the Allegheny Front escarpment base and forms the boundary between the Appalachian Plateau to the northwest and the Ridge and Valley Province to the southeast. The Lycoming and Towanda Creek valleys follow a probable northeastern Bald Eagle through valley extension and a probable southern extension continues southward along the Allegheny Front base by crossing Juniata River tributary drainage basins to reach the Potomac River drainage basin. Landform features identified on topographic maps, which include through valleys (valleys crossing drainage divides), barbed tributaries, drainage route orientations, drainage route direction changes, water gaps, and gaps located along the Allegheny Front crest, are used to reconstruct how the Pennsylvania Susquehanna and Juniata River drainage systems developed. The resulting geomorphic history describes how massive southwest-oriented floods moving across what was probably a low relief and rising surface (now preserved if preserved at all by the region’s highest elevations) flowed to an actively eroding Potomac River drainage system before being captured and sometimes reversed first by Juniata River valley headward erosion, second by West Branch Susquehanna River valley headward erosion (to create northeast-oriented Bald Eagle Creek and the northeast-oriented West Branch Susquehanna River segment) and third by North Branch Susquehanna River valley headward erosion. This interpretation explains most if not all of the previously poorly explained and unexplained topographic map evidence. 展开更多
关键词 Allegheny Front Appalachian Plateau Barbed Tributaries Juniata River Susquehanna River Ridge and Valley Province
下载PDF
Yellowstone Region Drainage History as Determined from the 1955 Ashton, Idaho, Montana, and Wyoming 1:250,000 Scale Topographic Map, USA
5
作者 Eric Clausen 《Open Journal of Geology》 CAS 2024年第3期317-338,共22页
The United States Geological Survey (USGS) 1955 (revised in 1972) Ashton topographic map (Ashton map) with a 1:250,000 scale and a 200-foot (about 60-meter) contour interval covers almost all of Yellowstone National P... The United States Geological Survey (USGS) 1955 (revised in 1972) Ashton topographic map (Ashton map) with a 1:250,000 scale and a 200-foot (about 60-meter) contour interval covers almost all of Yellowstone National Park and some adjacent regions to the south and west. In spite of numerous publications discussing Yellowstone region geologic history the drainage system and erosional landform evidence on the Ashton map appears to have been ignored. Drainage divides identifiable on the Ashton map separate the north-oriented Yellowstone, Gallatin, Madison, and Jefferson River drainage basins (which are located to the north and east of the continental divide with their water flowing to the Missouri River and ultimately the Gulf of Mexico) from the south-oriented Snake River drainage basin (with its water eventually reaching the Pacific Ocean). The Ashton map shows water-eroded passes and through valleys which link diverging and converging valleys which drain in opposite directions from the continental divide. These diverging and converging valleys suggest large volumes of south-oriented water once flowed across the Yellowstone region continental divide and some other Ashton map drainage divides. The accepted geology and glacial history paradigm (accepted paradigm) cannot satisfactorily explain the Ashton map drainage system and erosional landform evidence, which may be why geomorphologists have never addressed the map evidence. A new and fundamentally different geology and glacial history paradigm requiring the Yellowstone region to be located on the rim of a continental ice sheet created and occupied deep “hole” (which was uplifted as immense meltwater floods flowed across it) explains Ashton map drainage system and erosional landform evidence, but raises questions about previously published Yellowstone region geologic histories. 展开更多
关键词 Continental Divide Firehole River Gallatin River GEOMORPHOLOGY Madison River Snake River
下载PDF
Monitoring and evaluation of the water quality of the Lower Neches River, Texas, USA
6
作者 Qin Qian Mengjie He +1 位作者 Frank Sun Xinyu Liu 《Water Science and Engineering》 EI CAS CSCD 2024年第1期21-32,共12页
Increasing bacteria levels in the Lower Neches River caused by Hurricane Harvey has been of a serious concern.This study is to analyze the historical water sampling measurements and real-time water quality data collec... Increasing bacteria levels in the Lower Neches River caused by Hurricane Harvey has been of a serious concern.This study is to analyze the historical water sampling measurements and real-time water quality data collected with wireless sensors to monitor and evaluate water quality under different hydrological and hydraulic conditions.The statistical and Pearson correlation analysis on historical water samples determines that alkalinity,chloride,hardness,conductivity,and pH are highly correlated,and they decrease with increasing flow rate due to dilution.The flow rate has positive correlations with Escherichia coli,total suspended solids,and turbidity,which demonstrates that runoff is one of the causes of the elevated bacteria and sediment loadings in the river.The correlation between E.coli and turbidity indicates that turbidity greater than 45 nephelometric turbidity units in the Neches River can serve as a proxy for E.coli to indicate the bacterial outbreak.A series of statistical tools and an innovative two-layer data smoothing filter are developed to detect outliers,fill missing values,and filter spikes of the sensor measurements.The correlation analysis on the sensor data illustrates that the elevated sediment/bacteria/algae in the river is either caused by the first flush rain and heavy rain events in December to March or practices of land use and land cover.Therefore,utilizing sensor measurements along with rainfall and discharge data is recommended to monitor and evaluate water quality,then in turn to provide early alerts on water resources management decisions. 展开更多
关键词 Water quality Pearson correlation analysis Lower Neches River YSI wireless sensors Non-point pollution
下载PDF
Trends in oxycodone and oxycodone-containing analgesics administration for back pain in emergency departments in the USA(2007–2018)
7
作者 Jonathan Chabon Jemer Garrido +2 位作者 Deanna Schreiber-Gregory Jefferson Drapkin Sergey Motov 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2024年第3期169-174,共6页
BACKGROUND:To describe trends in oxycodone and oxycodone-containing analgesic prescribing for the treatment of back pain among adults in emergency departments(EDs) in the USA from 2007 to 2018.METHODS:Data were gather... BACKGROUND:To describe trends in oxycodone and oxycodone-containing analgesic prescribing for the treatment of back pain among adults in emergency departments(EDs) in the USA from 2007 to 2018.METHODS:Data were gathered from the National Hospital Ambulatory Medical Care Survey(NHAMCS) from 2007 to 2018.The study population included individuals of all ages presenting to USA EDs.The NHAMCS reasons for visit and oxycodone drug ID codes were used to isolate patients with back pain.The main outcome was the proportion of oxycodone and oxycodone-containing analgesics prescribed for back pain in the EDs over the specified time period.RESULTS:There was a relative decrease in the overall administration of oxycodone for back pain in the EDs by 62.3% from 2007(244,000 visits) to 2018(92,000 visits).The proportion of ED patients prescribed with oxycodone-containing analgesics for back pain increased among patients aged 45 years and older(from 43.8% to 57.6%),female patients(from 54.5% to 62.0%),black patients(from 22.5% to 30.4%),and Hispanic/Latino patients(from 9.4% to 19.6%).Oxycodone/acetaminophen was most prescribed and accounted for 90.2% of all oxycodone-containing analgesics in 2007,with a decrease to 68.5% in 2018.Pure oxycodone was the second most prescribed medication,accounting for 6.1% in 2007 and 31.5% in 2018.CONCLUSION:The overall number of oxycodone-containing analgesics decreased significantly from 2007 to 2018.However,that number trended upward in 45-year-old and older,female,black,or Hispanic/Latino patients from 2007 to 2018.The total amount of pure oxycodone increased significantly from 2007 to 2008. 展开更多
关键词 OXYCODONE Back pain Emergency department
下载PDF
Evaluation of Human Impacts on Bartlett Pond Ecosystem, Laredo, Southern Texas, USA, through Empirical Modeling
8
作者 Maya P. Bhatt Amede Rubio +6 位作者 Ganesh B. Malla Cristobal Lopez Virginia Morales Erick Vazquez Cano David Marquez Orlando Berumen Alvarez Alfred Addo-Mensah 《Journal of Environmental Protection》 2024年第4期497-526,共30页
The trace elements chemistry of Bartlett Pond, a small shallow wetland pond in Laredo, Southern Texas, was sampled to evaluate the dynamics of trace elements impacts on water quality and ecosystems ecology of the pond... The trace elements chemistry of Bartlett Pond, a small shallow wetland pond in Laredo, Southern Texas, was sampled to evaluate the dynamics of trace elements impacts on water quality and ecosystems ecology of the pond. Two types of fish (bass and tilapia) were also sampled to see the trace element accumulation in different parts of their body. The concentrations of trace elements in water samples were found in the following order: Fe &Gt;Sb > Pb > As &Gt;Co > Tl > Cr > Cd within Bartlett Pond. Overall, the water quality of the pond is unacceptable for drinking and any other purposes as trace element concentrations (e.g. As, Cd, Co, Cr, Pb, Fe, Sb and Tl) are exceedingly higher (several fold) than the WHO and US EPA guidelines. Predictive and correlation analysis shows that most trace elements exhibit a strong positive correlation among them indicating the same anthropogenic sources and biogeochemical processes regulate these trace elements within the pond. Distributions of the trace elements in water exhibit different shapes mostly as positively skewed distribution for As, Cd, Co, Cr, and Tl, symmetrical distribution for Fe and almost symmetrical distribution for Pb and Sb. Concentrations of As, Co and Tl accumulated much higher in different parts of the Bass than Tilapia fish. The concentrations of As, Tl, Co, and Sb appeared significantly higher in different parts of the body of both Bass and Tilapia than the maximum SRM certified values. Accumulation of these contaminants in fish tissues pose increased health risks to humans who consume these contaminated fish although fishing is prohibited. Anthropogenic activities in the region primarily degrade the whole pond ecosystem ecology of the Bartlett Pond and waters of this pond to be not recommended for any use. These findings may be useful for the scientific community and concerned authorities to improve understanding about these precious natural resources and conservation of the ecosystem ecology. 展开更多
关键词 Trace Elements Bartlett Pond Laredo Southern Texas WETLANDS Ecosystem Ecology
下载PDF
Implications of de Facto Reuse on Future Regulatory Developments for Beaufort-Jasper Water & Sewer Authority in Okatie, South Carolina, USA
9
作者 Tricia H. Kilgore Shubhashini Oza +1 位作者 Jeremy Hatfield Katherine Y. Bell 《Journal of Environmental Protection》 2024年第2期173-192,共20页
A significant portion of the national water supply can be attributed to de facto or unplanned potable reuse, though the extent of its contribution is difficult to estimate. Fortunately, the contribution of Water Resou... A significant portion of the national water supply can be attributed to de facto or unplanned potable reuse, though the extent of its contribution is difficult to estimate. Fortunately, the contribution of Water Resource Recovery Facility (WRRF) effluent to waters that supply drinking water treatment plants has been documented by some communities. In the United States (US), among the top 25 most impacted drinking water treatment plants by upstream WRRF, 16% of the influent flow to the drinking water treatment plant under average streamflow and up to 100% under low-flow conditions is WRRF effluent. Currently, the full extent of de facto reuse in the US may be much higher because of population growth. The scenario is no different for Beaufort-Jasper Water and Sewer Authority (BJWSA) in South Carolina, US, with contributions to the Savannah River originating from numerous WRRF and other upstream dischargers. South Carolina coastal utilities such as BJSWA are considering direct and indirect potable reuse options, driven by disposal limitations and challenges. Currently, South Carolina does not have a framework, guidelines, or regulations for reuse, but discussions have started among the regulated community. In addition to understanding the extent of de facto reuse, the state will need to develop standards and best practices to enable future adoption of planned potable reuse solutions to water resources challenges. Such guidance should address human health risk management and technical considerations regarding treatment in addition to other factors, including source control, storage, fail-safe operation, monitoring, non-cost factors, and public acceptance. This study conducted a mapping assessment specific to BJWSA, sampled at four locations on Savannah River, and observed that de facto reuse is approximately 4.6% to 5.9% during low-flow months and is within the range generally observed nationwide. When coupled with evidence that planned potable reuse can improve human health and environmental risks, this practice is a meaningful option in the water supply portfolio for many utilities. 展开更多
关键词 Water Reuse De Facto Reuse Planned Potable Reuse Water Recycling Wastewater Derived Contaminants
下载PDF
Soil Profile Concentration Distributions of Antimony and Bismuth across Southeastern Missouri (USA)
10
作者 Michael Aide 《Journal of Environmental Protection》 2024年第5期537-551,共15页
Recent research has suggested that increased industrial and technological utilization of antimony and bismuth necessitates greater research to determine the soil and water chemistry and the environmental risks associa... Recent research has suggested that increased industrial and technological utilization of antimony and bismuth necessitates greater research to determine the soil and water chemistry and the environmental risks associated with these elements. The near-total soil profile concentrations of antimony and bismuth were determined for key soil series across southeastern Missouri. The antimony concentrations ranged from 0.65 to 0.08 mg kg<sup>−</sup><sup>1</sup>, whereas the bismuth soil profile concentrations ranged from 0.92 to 0.03 mg kg<sup>−</sup><sup>1</sup>. Most pedons showed antimony concentrations ranging from 20 to 30 mg kg<sup>−</sup><sup>1</sup>, whereas bismuth concentrations were commonly 10 to 20 mg kg<sup>−</sup><sup>1</sup>. For soils having argillic horizons, antimony and bismuth concentrations were greater for the illuvial horizons than the eluvial horizons, whereas Entisols, Inceptisols, and one Vertisol showed rather uniform antimony and bismuth concentrations, features paralleling the soil texture distribution. Both antimony and bismuth showed significant correlations with iron. 展开更多
关键词 Trace Elements ANTIMONY BISMUTH SOILS Group 15
下载PDF
Perceptions of Bark Beetle Landscape Disturbance Effects on Natural Resources and Drinking Water: Assessing Communication and Knowledge Exchange in the Rocky Mountain Region, USA
11
作者 Stuart P. Cottrell Katherine Mattor Jana Raadik Cottrell 《Open Journal of Ecology》 2024年第1期77-100,共24页
Widespread changes to forested watersheds affected by the mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic across western North America raised concerns about the effects of this climate-induced disturba... Widespread changes to forested watersheds affected by the mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic across western North America raised concerns about the effects of this climate-induced disturbance on drinking water and natural resources. Effective communication and knowledge exchange across scientists and stakeholders (i.e., drinking water managers) is essential for constructively responding to such landscape scale disturbances, providing improved adaptive capacity through knowledge sharing. An assessment of stakeholder knowledge levels, information needs, primary concerns, and suggested communication strategies were conducted via an online elicitation survey and World Science Café workshops. Knowledge levels, assessed via a survey of local water managers and experts, were relatively low with approximately half of the respondents reporting little to no knowledge of the effects of mountain pine beetle on drinking water quality and quantity, thereby indicating limited knowledge exchange between scientists and drinking water stakeholders. Increased accessibility and dissemination of research findings pertinent to the mountain pine beetle epidemic’s effects on drinking water quality and quantity is necessary for natural resource management. Recommendations for improved communication among scientists and drinking water stakeholders in particular and forest health in general include dispersal of non-academic research summaries, information exchange through existing media and community resources, demonstration projects, and information clearinghouses. This information provides a better understanding of the challenges, concerns, and first-hand experience of stakeholders of a landscape disturbance issue to apply this knowledge to enhance land management practice and how researchers on this overall project enhanced science communication efforts. 展开更多
关键词 Adaptive Capacity Climate Change Forested Watersheds Water Quality Water Quantity
下载PDF
Diversity, Ecology, and Environmental Significance of Foraminifera in Al Hamama and Susah Coastal Regions, Northeastern Libya: Insights from Holocene Sediments
12
作者 Belkasim Khameiss Husamaldeen Zubi 《Journal of Environmental Protection》 2024年第1期13-25,共13页
This research initiative, conducted along the coastal zones of Al Hamama and Susah in northeastern Libya, aimed to enhance our understanding of Holocene benthic foraminifera assemblages and the paleoenvironmental para... This research initiative, conducted along the coastal zones of Al Hamama and Susah in northeastern Libya, aimed to enhance our understanding of Holocene benthic foraminifera assemblages and the paleoenvironmental parameters in the region. We meticulously gathered five sediment samples to analyze the composition of foraminifera populations within the unconsolidated sedimentary deposits adjacent to these locations. We successfully identified nine distinct benthic foraminifera species, including Amphistegina lobifera, Eliphidium crispum, Sigmoilinita tenuis, Sorites orbiculus, Stomatorbina concentrica, Peneroplis planatus, Pseudotriloculina rotunda, Pyrgoella sphaera, and Triloculina schreberiana. Notably, Eliphidium crispum and Amphistegina lobifera emerged as the most prevalent species. These foraminifera species exhibited distinct ecological preferences, shedding light on paleoenvironmental conditions and climatic fluctuations during the Quaternary Period in the Susah and Al Hamama coastal regions. The presence of Orbulina universa, a planktonic foraminifera species, further enriched our understanding of the paleoenvironment by providing insights into specific water depths and temperature ranges. This research significantly contributes to paleoceanography and environmental reconstruction, highlighting the invaluable use of foraminifera as proxies for exploring past environmental changes. Additionally, the study investigated the impacts of anthropogenic influences on benthic ecosystems in the Al Hamama and Susah coastal areas. These influences included reworked foraminifera specimens and the effects of karst formations, acid rain, and eutrophication. Notably, human-induced factors have visibly affected biogenic fauna and ecosystem dynamics in the study area. Consequently, this research provides valuable insights into paleoenvironmental conditions and ecological dynamics within the Susah and Al Hamama coastal regions, emphasizing the crucial role of foraminifera in reconstructing historical environmental fluctuations. 展开更多
关键词 Al Hamama Susah Northeastern Libya Holocene Sediments
下载PDF
Spatiotemporal dynamics of the social structure of Indo-Pacific humpback dolphins(Sousa chinensis)in Xiamen waters from 2007 to 2019
13
作者 Yi Lu Xin-Rong Xu +3 位作者 Bing-Yao Chen Thomas A Jefferson Holly Fearnbach Guang Yang 《Zoological Research》 SCIE CSCD 2024年第2期439-450,共12页
As highly social animals,Indo-Pacific humpback dolphins(Sousa chinensis)exhibit community differentiation.Nevertheless,our understanding of the external and internal factors influencing these dynamics,as well as their... As highly social animals,Indo-Pacific humpback dolphins(Sousa chinensis)exhibit community differentiation.Nevertheless,our understanding of the external and internal factors influencing these dynamics,as well as their spatiotemporal variations,is still limited.In the present study,variations in the social structure of an endangered Indo-Pacific humpback dolphin population in Xiamen Bay,China,were monitored over two distinct periods(2007–2010 and 2017–2019)to analyze the effects of habitat utilization and the composition of individuals within the population.In both periods,the population demonstrated a strikingly similar pattern of social differentiation,characterized by the division of individuals into two main clusters and one small cluster.Spatially,the two primary clusters occupied the eastern and western waters,respectively,although the core distribution area of the eastern cluster shifted further eastward between the two periods.Despite this distribution shift,the temporal stability of the social structure and inter-associations within the eastern cluster remained unaffected.A subset of 16individuals observed in both periods,comprising 51.6%and 43.2%of the population in each respective period,emerged as a foundational element of the social structure and may be responsible for sustaining social structure stability,especially during the 2007–2010 period.These observations suggest that the composition of dominant individuals,an internal factor,had a more substantial influence on the formation of the social network than changes in habitat use,an external factor.Consequently,the study proposes distinct conservation measures tailored to each of the two main clusters. 展开更多
关键词 Social differentiation Social structure Sousa chinensis DYNAMICS CONSERVATION
下载PDF
What-If XAI Framework (WiXAI): From Counterfactuals towards Causal Understanding
14
作者 Neelabh Kshetry Mehmed Kantardzic 《Journal of Computer and Communications》 2024年第6期169-198,共30页
People learn causal relations since childhood using counterfactual reasoning. Counterfactual reasoning uses counterfactual examples which take the form of “what if this has happened differently”. Counterfactual exam... People learn causal relations since childhood using counterfactual reasoning. Counterfactual reasoning uses counterfactual examples which take the form of “what if this has happened differently”. Counterfactual examples are also the basis of counterfactual explanation in explainable artificial intelligence (XAI). However, a framework that relies solely on optimization algorithms to find and present counterfactual samples cannot help users gain a deeper understanding of the system. Without a way to verify their understanding, the users can even be misled by such explanations. Such limitations can be overcome through an interactive and iterative framework that allows the users to explore their desired “what-if” scenarios. The purpose of our research is to develop such a framework. In this paper, we present our “what-if” XAI framework (WiXAI), which visualizes the artificial intelligence (AI) classification model from the perspective of the user’s sample and guides their “what-if” exploration. We also formulated how to use the WiXAI framework to generate counterfactuals and understand the feature-feature and feature-output relations in-depth for a local sample. These relations help move the users toward causal understanding. 展开更多
关键词 XAI AI WiXAI Causal Understanding COUNTERFACTUALS Counterfactual Explanation
下载PDF
Glacial Cover Assessment from 1993 to 2021 Using Normalized Difference Snow Index with Landsat Imagery in the Colorado Front Range, USA
15
作者 Jiaqi Zhang 《Journal of Geoscience and Environment Protection》 2024年第5期69-80,共12页
Cirque glaciers found on the Colorado Front Range, USA are sensitive to climate change and are important for water supply and the delivery of water downstream. These glaciers are shrinking at a rapid rate in response ... Cirque glaciers found on the Colorado Front Range, USA are sensitive to climate change and are important for water supply and the delivery of water downstream. These glaciers are shrinking at a rapid rate in response to the global climate change, and thus it is important to track and analyze them. One of the ways to monitor these glaciers is by using multispectral satellite imagery (Landsat imagery). In this article, the feasibility of tracking glacial area via Landsat satellites has been discussed and the trend of 13 glaciers in the Colorado Front Range Region has been analyzed from 1993 to 2021. In this period, the total glacial area across 13 glaciers in the Colorado Front Range Region has decreased by 63.6%, and a significant correlation (p-value p < 0.05) found with the annual global average temperature indicates that the retraction of glaciers is likely a response to the global warming. 展开更多
关键词 Cirque Glaciers Colorado Front Range Global Warming Landsat Satellites NDSI
下载PDF
Psychiatric comorbidities in epilepsy:population co-occurrence,genetic correlations and causal effects
16
作者 Viktor H Ahlqvist Christina Dardani +14 位作者 Paul Madley-Dowd Harriet Forbes Jessica Rast Caichen Zhong Renee M Gardner Christina Dalman Kristen Lyal cRAIG Newschaffer Torbjorn Tomson Michael Lundberg Daniel Berglind Neil M Davies Brian K Lee Cecilia Magnusson Dheeraj Rai 《General Psychiatry》 CSCD 2024年第1期103-111,共9页
Background Psychiatric comorbidities are common in patients with epilepsy.Reasons for the co-occurrence of psychiatric conditions and epilepsy remain poorly understood.Aim We aimed to triangulate the relationship betw... Background Psychiatric comorbidities are common in patients with epilepsy.Reasons for the co-occurrence of psychiatric conditions and epilepsy remain poorly understood.Aim We aimed to triangulate the relationship between epilepsy and psychiatric conditions to determine the extent and possible origins of these conditions.Methods Using nationwide Swedish health registries,we quantified the lifetime prevalence of psychiatric disorders in patients with epilepsy.We then used summarydata from genome-wide association studies to investigate whether the identified observational associations could be attributed to a shared underlying genetic aetiology using cross-trait linkage disequilibrium score regression.Finally,we assessed the potential bidirectional relationships using two-sample Mendelian randomisation.Results In a cohort of 7628495 individuals,we found that almost half of the 94435 individuals diagnosed with epilepsy were also diagnosed with a psychiatric condition in their lifetime(adjusted lifetime prevalence,44.09%;95%confidence interval(Cl)43.78%to 44.39%).We found evidence for a genetic correlation between epilepsy and some neurodevelopmental and psychiatric conditions.For example,we observed a genetic correlation between epilepsy and attention-deficit/hyperactivity disorder(r,=0.18,95%Cl 0.09 to 0.27,p<0.001)—a correlation that was more pronounced in focal epilepsy(r=0.23,95%CI 0.09 to 0.36,p<0.001).Findings from Mendelian randomisation using common genetic variants did not support bidirectional effects between epilepsy and neurodevelopmental or psychiatric conditions.Conclusions Psychiatric comorbidities are common in patients with epilepsy.Genetic correlations may partially explain some comorbidities;however,there is little evidence of a bidirectional relationship between the genetic liability of epilepsy and psychiatric conditions.These findings highlight the need to understand the role of environmental factors or rare genetic variations in the origins of psychiatric comorbidities in epilepsy. 展开更多
关键词 EPILEPSY Psychiat LIFETIME
下载PDF
Causal associations between major depressive disorder and COVID-19 被引量:2
17
作者 Ancha Baranova Yi Zhao +1 位作者 Hongbao Cao Fuquan Zhang 《General Psychiatry》 CSCD 2023年第2期114-120,共7页
Background We aimed to evaluate whether major depressive disorder(MDD)could aggravate the outcomes of coronavirus disease 2019(COVID-19)or whether the genetic liability to COVID-19 could trigger MDD.Aims We aimed to a... Background We aimed to evaluate whether major depressive disorder(MDD)could aggravate the outcomes of coronavirus disease 2019(COVID-19)or whether the genetic liability to COVID-19 could trigger MDD.Aims We aimed to assess bidirectional causal associations between MDD and COVID-19.Methods We performed genetic correlation and Mendelian randomisation(MR)analyses to assess potential associations between MDD and three COVID-19 outcomes.Literature-based network analysis was conducted to construct molecular pathways connecting MDD and COVID-19.Results We found that MDD has positive genetic correlations with COVID-19 outcomes(rg:0.10–0.15).Our MR analysis indicated that genetic liability to MDD is associated with increased risks of COVID-19 infection(odds ratio(OR)=1.05,95%confidence interval(CI):1.00 to 1.10,p=0.039).However,genetic liability to the three COVID-19 outcomes did not confer any causal effects on MDD.Pathway analysis identified a panel of immunity-related genes that may mediate the links between MDD and COVID-19.Conclusions Our study suggests that MDD may increase the susceptibility to COVID-19.Our findings emphasise the need to increase social support and improve mental health intervention networks for people with mood disorders during the pandemic. 展开更多
关键词 IMMUNITY connecting ANALYSIS
下载PDF
Shared genetics and bidirectional causal relationships between type 2 diabetes and attention-deficit/hyperactivity disorder 被引量:1
18
作者 Ancha Baranova Vikas Chandhoke +1 位作者 Hongbao Cao Fuquan Zhang 《General Psychiatry》 CSCD 2023年第2期106-113,共8页
Background Type 2 diabetes(T2D)is a chronic metabolic disorder with high comorbidity with mental disorders.The genetic links between attention-deficit/hyperactivity disorder(ADHD)and T2D have yet to be elucidated.Aims... Background Type 2 diabetes(T2D)is a chronic metabolic disorder with high comorbidity with mental disorders.The genetic links between attention-deficit/hyperactivity disorder(ADHD)and T2D have yet to be elucidated.Aims We aim to assess shared genetics and potential associations between ADHD and T2D.Methods We performed genetic correlation,two-sample Mendelian randomisation and polygenic overlap analyses between ADHD and T2D.The genome-wide association study(GWAS)summary results of T2D(80154 cases and 853816 controls),ADHD2019(20183 cases and 35191 controls from the 2019 GWAS ADHD dataset)and ADHD2022(38691 cases and 275986 controls from the 2022 GWAS ADHD dataset)were used for the analyses.The T2D dataset was obtained from the DIAGRAM Consortium.The ADHD datasets were obtained from the Psychiatric Genomics Consortium.We compared genome-wide association signals to reveal shared genetic variation between T2D and ADHD using the larger ADHD2022 dataset.Moreover,molecular pathways were constructed based on large-scale literature data to understand the connection between ADHD and T2D.Results T2D has positive genetic correlations with ADHD2019(rg=0.33)and ADHD2022(rg=0.31).Genetic liability to ADHD2019 was associated with an increased risk for T2D(odds ratio(OR):1.30,p<0.001),while genetic liability to ADHD2022 had a suggestive causal effect on T2D(OR:1.30,p=0.086).Genetic liability to T2D was associated with a higher risk for ADHD2019(OR:1.05,p=0.001)and ADHD2022(OR:1.03,p<0.001).The polygenic overlap analysis showed that most causal variants of T2D are shared with ADHD2022.T2D and ADHD2022 have three overlapping loci.Molecular pathway analysis suggests that ADHD and T2D could promote the risk of each other through inflammatory pathways.Conclusions Our study demonstrates substantial shared genetics and bidirectional causal associations between ADHD and T2D. 展开更多
关键词 diabetes OVERLAP CAUSAL
下载PDF
拔尖创新人才培养的理论基础和实践思路 被引量:25
19
作者 戴耘 《华东师范大学学报(教育科学版)》 北大核心 2024年第1期1-23,共23页
拔尖创新人才的培养是一个现实而又紧迫的话题,但关于什么是“拔尖创新人才”,如何选拔和培养这类人才,尚缺乏成熟的理论准备和实践引导。本文旨在对创新潜能、发展、成就的理论以及对应的识别、培养、文化支持等社会实践做一个系统概... 拔尖创新人才的培养是一个现实而又紧迫的话题,但关于什么是“拔尖创新人才”,如何选拔和培养这类人才,尚缺乏成熟的理论准备和实践引导。本文旨在对创新潜能、发展、成就的理论以及对应的识别、培养、文化支持等社会实践做一个系统概要的阐述。首先,在拔尖创新人才的界定上,本文提出了创新的五种形态和创新人才的两种不同类型。第二,在创新人才的识别问题上,本文提出了基于人才动态发展观并结合“总体筛选”和“个体考察”的人才识别模式。第三,在发展和培养问题上,本文提出兼顾成长阶段和领域具体性同时突出“探索未知”和“开放性”的培养模式。第四,在创新成就的文化支持上,本文探讨了如何在创新实践中营造兼容认知多样性和鼓励自由探索的生态环境。第五,本文进一步针对现有教育体制提出了五个实践策略上的着眼点。最后,关于教育实践的政策导向,本文提出了四个基本原则和四种认知误区。 展开更多
关键词 创新人才 创新类型 创新潜能 心智发展 人才识别 培养模式 创新文化 教育政策
下载PDF
下一代个性化学习:生成式人工智能增强智能辅导系统 被引量:6
20
作者 徐升 佟佳睿 胡祥恩 《开放教育研究》 北大核心 2024年第2期13-22,共10页
长期以来,教育技术领域的研究者致力于利用计算机开展个性化自适应教学。智能辅导系统作为这一领域的核心,其目标是通过计算机技术提供个性化学习体验和支持。近年来,生成式人工智能,尤其是大语言模型的发展,为智能辅导系统带来了突破... 长期以来,教育技术领域的研究者致力于利用计算机开展个性化自适应教学。智能辅导系统作为这一领域的核心,其目标是通过计算机技术提供个性化学习体验和支持。近年来,生成式人工智能,尤其是大语言模型的发展,为智能辅导系统带来了突破性机遇,为个性化学习开辟了新的路径。本文回顾了研究者为实现个性化学习所作的努力及其成果和局限,探讨了大语言模型在个性化学习中的潜力和影响,介绍了“苏格拉底游乐园”——一个基于对话的智能辅导系统,如何利用大语言模型实施苏格拉底式教学,揭示了生成式人工智能如何革新个性化学习方式。针对大语言模型的潜在误用,文章提出了相应的建议,并构建了框架,旨在引导研发者在生成式人工智能和大语言模型范式下开发高效的智能教育应用。 展开更多
关键词 个性化学习 智能辅导系统 ChatGPT 对话教学系统
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部