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南非太阳紫外线B曝射量的时空变化:对受威胁分类群的影响

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人类环境杂志 1999年第5期28卷 450-456页

作者： CharlesF.Musil Michael C.Rutherford Leslie W.Powrie David j.mcdonald Lars Olof Bjrn 孙颖 National Botanical Institute Private Bag X7Clarent 7735 National Botanical Institute Private Bag X7Claremont 7735 气候变化科研小组生态及保护出生物保护小组隆德大学植物生理学系北京大学城市与环境学系

南非大阳光中的UV-B(28～315nm)曝射量在空间和时间上的变化是按2.5km^2的分辨率用臭氧、相对湿度、云量及海拔高度数据进行模拟并绘图的。计算机处理的结果显示,UV-B曝射量存在着很大的天然梯度,纬度跨越14度,变化幅度为34.2%,经度跨... 详细信息

南非大阳光中的UV-B(28～315nm)曝射量在空间和时间上的变化是按2.5km^2的分辨率用臭氧、相对湿度、云量及海拔高度数据进行模拟并绘图的。计算机处理的结果显示,UV-B曝射量存在着很大的天然梯度,纬度跨越14度,变化幅度为34.2%,经度跨越16度,UV-B变化幅度为44.2%。对未来UV-B年曝射量情况的模拟显示出其小辐增长的趋势,2003年增加2.5%(臭氧耗减过程的最佳状况);2051年增加8.1%(臭氧耗减过程的最差状况)。值得注意的是,防臭氧耗减,UV-B的年内变率显著增加。2003年深秋(5月)曝射量增加12%,2051年同一季节增加35%。对代表103科468属的2146种受威胁(稀有、濒危、脆弱)生物分析其分类、生活型和机能特征,并将它们的分布与模拟得到的UV-B时空分布型式相比较。我们看到,在受威胁分类群中,常绿和内质的生活型及地下芽植物出现的比例很高,这说明,这些植物时太阳先中UV-B作用的增强有很高的生理修复能力,尽管有些生活型(如树木)的抵抗力显得相对差一些。有些植物机能类型(如一年生本本植物)显示出单位繁殖产出的降低及植物总体适应水平的下降,这些可能会导致物种共存型式、植物组成成分和多样性的改变。

关键词：南非太阳光紫外线B曝射量时空变化植物危害

Clay mineral formation and transformation in non-marine environments and implications for Early Cretaceous palaeoclimatic evolution:The Weald Basin,Southeast England

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journal of Palaeogeography 2022年第3期11卷 387-409页

作者： Oladapo O.Akinlotan Ogechukwu A.Moghalu stuart j.Hatter Sunday Okunuwadje Lorna Anquilano Uche Onwukwe Safiyeh Haghani Okwudiri A.Anyiam Byami A.jolly Department of Geography University of SussexFalmerBrightonBN19SJUnited Kingdom Department of Geology University of NigeriaNsukka Road410001NsukkaNigeria Badley Ashton and Associates Ltd Winceby HouseWincebyHorncastleLincolnshireLN96PBUnited Kingdom Department of Geology and Geophysics School of GeosciencesKings’CollegeUniversity of AberdeenScotlandAB243UEUnited Kingdom Experimental Techniques Centre Brunel University LondonBragg 16Brunel University LondonUxbridgeUB83PHUnited Kingdom Department of Geology Ahmadu Bello UniversityZariaNigeria

Analyses of clay minerals within the Early Cretaceous Weald Basin,Southeast England reveal kaolinite,illite and chlorite as the main detrital clay minerals while glauconite and smectite are subordinates.A kaolinite-rich assemblage which characterized the sand-dominated Ashdown and Tunbridge Wells Sand formations and an illite-dominated assemblage associated mostly with the Wadhurst Clay and Weald Clay formations are *** was enriched in the Ashdown and Tunbridge Wells Sand formations during warm and humid climate with high precipitation that encouraged chemical weathering and leaching,while cold and dry conditions favoured the concentration of illite in the Wadhurst Clay and Weald Clay *** patterns associated with warm climate were drastically reduced during the drier climatic *** clay minerals are detrital in origin,with chlorite being more prominent than previously *** to previous studies and assumptions,this study revealed that authigenic clay minerals are present in the Hastings Beds,with vermiform and mica-replacive kaolinite being the most common,consistent with humid depositional *** authigenic illite is also present,along with a chloritized grain,providing evidence for *** absence of dickite and occurrence of kaolinite,suggest that authigenic illite formed in relatively shallow burial conditions,indicating a maximum burial depth of2500 m-3000 m,about 1000 m deeper than previous estimates of 1500 m-2000 *** clay minerals are absent in the Weald Clay Formation possibly because of hindered flow of meteoric water and limited growth space for authigenic *** study is significant in:1)reinforcing multiple methods to facilitate a robust and balanced knowledge of formation and transformation of clay minerals;2)investigating detrital and authigenic clay mineral assemblages when assessing the palaeoenvironments of sedimentary basins.

关键词： Clay minerals Clay mineral transformation Palaeoclimate Early Cretaceous Weald Basin Wealden Southeast England

Effects of amyloid precursor protein peptide APP96-110,alone or with human mesenchymal stromal cells,on recovery after spinal cord injury

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Neural Regeneration Research 2022年第6期17卷 1376-1386页

作者： stuart I.Hodgetts Sarah j.Lovett D.Baron-Heeris A.Fogliani Marian Sturm C.Van den Heuvel Alan R.Harvey School of Human Sciences The University of Western Australia(UWA)PerthWAAustralia Perron Institute for Neurological and Translational Science PerthWAAustralia Cell and Tissue Therapies WA(CTTWA) Royal Perth HospitalPerthWAAustralia Adelaide Medical School Faculty of Health and Medical SciencesThe University of AdelaideAdelaideSAAustralia

Delivery of a peptide(APP96-110),derived from amyloid precursor protein(APP),has been shown to elicit neuroprotective effects following cerebral stroke and traumatic brain *** this study,the effect of APP96-110 or a mutant version of this peptide(mAPP96-110)was assessed following moderate(200 kdyn,(2 N))thoracic contusive spinal cord injury(SCI)in adult Nude *** received a single tail vein injection of APP96-110 or mAPP96-110 at 30 minutes post-SCI and were then assessed for functional improvements over the next 8 weeks.A cohort of animals also received transplants of either viable or non-viable human mesenchymal stromal cells(hMSCs)into the SC lesion site at one week post-injury to assess the effect of combining intravenous APP96-110 delivery with hMSC *** were perfused 8 weeks post-SCI and longitudinal sections of spinal cord analyzed for a number of factors including hMSC viability,cyst size,axonal regrowth,glial reactivity and macrophage *** of sensorimotor function revealed occasional significant differences between groups using Ladderwalk or Ratwalk tests,however there were no consistent improvements in functional outcome after any of the ***96-110 alone,and APP96-110 in combination with both viable and non-viable hMSCs significantly reduced cyst size compared to SCI *** treatments with donor hMSCs also significantly increased βIII tubulin^(+),glial fibrillary acidic protein(GFAP^(+))and laminin+expression,and decreased ED1^(+)expression in *** preliminary study demonstrates that intravenous delivery of APP96-110 peptide has selective,modest neuroprotective effects following SCI,which may be enhanced when combined with hMSC ***,the effects are less pronounced and less consistent compared to the protective morphological and cognitive impact that this same peptide has on neuronal survival and behaviour after stroke and traumatic brain *** while the efficacy of a

关键词： amyloid precursor protein cell transplantation combination contusion functional recovery mesenchymal stromal cells neuroprotection regeneration spinal cord injury tissue sparing

Doped graphene/carbon black hybrid catalyst giving enhanced oxygen reduction reaction activity with high resistance to corrosion in proton exchange membrane fuel cells

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journal of Energy Chemistry 2022年第5期31卷 143-153页

作者： Zhaoqi ji jianuo Chen María Pérez-Page Zunmin Guo Ziyu Zhao Rongsheng Cai Maxwell T.P.Rigby Sarah j.Haigh stuart M.Holmes School of Automotive Engineering Harbin Institute of TechnologyWeihai264209ShandongChina Department of Chemical Engineering and Analytical Science The University of ManchesterManchester M139PLUK Department of Materials The University of ManchesterManchester M139PLUK

Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(<30 mV). Meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.

关键词： Nitrogen doped graphene Low-temperature hydrogen fuel cell Catalyst degradation Carbon corrosion

Vegetation productivity responses to drought on tribal lands in the four corners region of the Southwest USA

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Frontiers of Earth Science 2018年第1期12卷 37-51页

作者： Mohamed Abd Salam EL-VILALY Kamel DIDAN stuart E. MARSH Willem j.D. VAN LEEUWEN Michael A. CRIMMINS Armando Barreto MUNOZ The Intemational Food Policy Research Institute Washington DC 20006-1002 USA Vegetation Index and Phenology Lab Department of Agricultural and Biosystems Engineering The University of Arizona Tucson AZ 85721-0036 USA Arizona Remote Sensing Center School of Natural Resources and the Environment The University of Arizona Tucson AZ 85721-0043 USA Department of Soils Water and Environmental Science The University of Arizona Tucson AZ 85721-0038 USA

For more than a decade, the Four Comers Region has faced extensive and persistent drought conditions that have impacted vegetation communities and local water resources while exacerbating soil erosion. These persistent droughts threaten ecosystem services, agriculture, and livestock activities, and expose the hypersensitivity of this region to inter-annual climate variability and change. Much of the intermountain Western United States has sparse climate and vegetation monitoring stations, making fine-scale drought assessments difficult. Remote sensing data offers the opportunity to assess the impacts of the recent droughts on vegetation productivity across these areas. Here, we propose a drought assessment approach that integrates climate and topographical data with remote sensing vegetation index time series. Multisensor Normalized Difference Vegetation Index （NDVI） time series data from 1989 to 2010 at 5.6 km were analyzed to characterize the vegetation productivity changes and responses to the ongoing drought. A multi-linear regression was applied to metrics of vegetation productivity derived from the NDVI time series to detect vegetation productivity, an ecosystem service proxy, and changes. The results show that around 60.13% of the study area is observing a general decline of greenness （p 〈 0.05）, while 3.87% show an unexpected green up, with the remaining areas showing no consistent change. Vegetation in the area show a significant positive correlation with elevation and precipitation gradients. These results, while, confirming the region＇s vegetation decline due to drought, shed further light on the future directions and challenges to the region＇s already stressed ecosystems. Whereas the results provide additional insights into this isolated and vulnerable region, the drought assessment approach used in this study may be adapted for application in other regions where surfacebased climate and vegetation monitoring record is spatially and temporally limited.

关键词： drought remote sensing Hopi Navajo Nation

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平面广告:与电视广告不分伯仲

广告主 2007年第12期 70-72页

作者： Robert Heath stuart mcdonald 全智

平面广告不仅比电视广告省钱得多,而且在塑造强大品牌上与电视广告具有同样的能力,在引起注意和传达信息上更比电视广告技高一筹。

关键词：电视广告平面广告省钱品牌

Electrophysiological assessment of primary cortical neurons genetically engineered using iron oxide nanoparticles

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Nano Research 2017年第8期10卷 2881-2890页

作者： Michael G. Evans Arwa Al-Shakli stuart I. jenkins Divya M. Chari School of Life Sciences Keele University Keele Staffordshire ST5 5BG UK Institute for Science and Technology in Medicine Keele University Keele Staffordshire ST5 5BG UK

The development of safe technologies to genetically modify neurons is of great interest in regenerative neurology, for both translational and basic science applications. Such approaches have conventionally been heavily reliant on viral transduction methods, which have safety and production limitations. Magnetofection （magnet-assisted gene transfer using iron oxide nanoparticles as vectors） has emerged as a highly promising non-viral alternative for safe and reproducible genetic modification of neurons. Despite the high potential of this technology, there is an important gap in our knowledge of the safety of this approach, namely, whether it alters neuronal function in adverse ways, such as by altering neuronal excitability and signaling. We have investigated the effects of magnetofection in primary cortical neurons by examining neuronal excitability using the whole cell patch clamp technique. We found no evidence that magnetofection alters the voltage-dependent sodium and potassium ionic currents that underpin excitability. Our study provides important new data supporting magnetofection as a safe technology for bioengineering of neuronal cell populations.

关键词： transfection magnetic nanoparticle green fluorescent protein (GFP) whole-cell patch clamp fluorescence microscopy

Post-weaning and whole-of-life performance of pigs is determined by live weight at weaning and the complexity of the diet fed after weaning

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Animal Nutrition 2017年第4期3卷 372-379页

作者： Cherie L.Collins john R.Pluske Rebecca S.Morrison Trevor N.mcdonald Robert j.Smits David j.Henman Ingunn Stensland Frank R.Dunshea Rivalea Australia Pty Ltd School of Veterinary and Life Sciences Murdoch University Faculty of Veterinary and Agricultural Sciences The University of Melbourne

The production performance and financial outcomes associated with weaner diet complexity for pigs of different weight classes at weaning were examined in this experiment. A total of 720 weaner pigs(360 entire males and 360 females) were selected at weaning(27 ± 3 d) and allocated to pens of 10 based on individual weaning weight(light weaning weight: pigs below 6.5 kg; medium weaning weight: 6.5 to8 kg; heavy weaning weight: above 8.5 kg). Pens were then allocated in a 3 x 2 x 2 factorial arrangement of treatments with the respective factors being weaning weight(heavy, medium and light; H, M and L,respectively), weaner diet complexity(high complexity/cost, HC; low complexity/cost, LC), and gender(male and female). Common diets were fed to both treatment groups during the final 4 weeks of the weaner period(a period of 39 days). In the first 6 d after weaning, pigs offered the HC diets gained weight faster and used feed more efficiently than those offered the LC diets(P = 0.031). Pigs fed a HC diet after weaning tended to be heavier at the sale live weight of 123 d of age compared with pigs fed the LC diet(P = 0.056). There were no other main effects of the feeding program on growth performance through to slaughter. Weaning weight had a profound influence on lifetime growth performance and weight at 123 d of age, with H pigs at weaning increasing their weight advantage over the M and L pigs(101.3,97.1, 89.6 kg respectively, P < 0.001). Cost-benefit analyses suggested there was a minimal benefit in terms of cost per unit live weight gain over lifetime when pigs were offered a HC feeding program to L,with a lower feed cost/kg gain. The results from this investigation confirm the impact of weaning weight on lifetime growth performance, and suggest that a HC feeding program should be focused on L weaner pigs(i.e., weaning weight less than 6.5 kg at 27 d of age) in order to maximise financial returns.

关键词： Pigs Performance Diet complexity Weaning weight Carcass characteristics Cost benefit analyses

Graphene/carbon structured catalyst layer to enhance the performance and durability of the high-temperature proton exchange membrane fuel cells

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journal of Energy Chemistry 2022年第12期75卷 399-407,I0011页

作者： Zhaoqi ji jianuo Chen Zunmin Guo Ziyu Zhao Rongsheng Cai Maxwell T.P.Rigby Sarah j.Haigh Maria Perez-Page Yitao Shen stuart M.Holmes School of Automotive Engineering Harbin Institute of Technology(Weihai)Weihai 264209ShandongChina Department of Chemical Engineering The University of ManchesterManchester M139PLUK Department of Materials The University of ManchesterManchester M139PLUK

In this study,nitrogen doped electrochemically exfoliated reduced graphene oxide and carbon black supported platinum(Pt/Nr EGO_(2)-CB_(3))has been prepared to enhance the performance and durability of hightemperature PEMFCs with lower Pt *** the one hand,Pt/Nr EGO_(2)-CB_(3)with the strong interaction between the Pt and nitrogen(N)prevent agglomeration of Pt particles and Pt particles is 5.46±1.46 nm,which is smaller than that of 6.78±1.34 nm in Pt/***,ECSA of Pt/Nr EGO_(2)-CB_(3)decrease 13.65%after AST,which is much lower than that of 97.99%in Pt/*** the other hand,the Nr EGO flakes in MEAac act as a barrier to mitigate phosphoric acid redistribution,which improves the formation of triple-phase boundaries(TPBs)and gives stable operation of the MEAacwith a lower decay rate of 0.02 mV h^(-1)within100 *** steady-state operation,the maximum power density of Pt/Nr EGO_(2)-CB_(3)(0.411 W cm^(-2))is three times higher than that of conventional Pt/C(0.134 W cm^(-2))in high-temperature *** AST,the mass transfer resistance of Pt/Nr EGO_(2)-CB_(3)electrode(0.560Ωcm^(2))is lower than that in Pt/C(0.728Ωcm^(2)).

关键词： High-temperature proton exchange membrane fuel cell Phosphoric acid loss Pt catalyst degradation Accelerated stress test Durability