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1Development of a PWM Precision Spraying Controller for Unmanned Aerial Vehicles显示文摘This paper presents a new Pulse Width Modulation (PWM) controller for Unmanned Aerial Vehicle (UAV) precisionsprayer for agriculture using a TL494 fixed-frequency pulse width modulator together with a data acquisition board and developedsoftware. An UAV can be remotely controlled or flown autonomously by pre-programmed flight plans. The PWMcontroller was implemented through the guidance system on the UAV with control commands sent between the UAV helicopterand the ground control station via a wireless telemetry system. The PWM controller was tested and validated using LabVIEW8.2. Several analyses were performed in a laboratory to test different control signals. The results show that the PWM controllerhas promise as a higher precision technique for spray applications, which will improve efficiency of pesticide application,especially in crop production areas.W.Clint Hoffmann Brad Fritz 2010Journal of Bionic Engineering2010,7,3:27
2ClimateAP: an application for dynamic local downscaling of historical and future climate data in Asia Pacific显示文摘While low-to-moderate resolution gridded climate data are suitable for climate-impact modeling at global and ecosystems levels, spatial analyses conducted at local scales require climate data with increased spatial accuracy. This is particularly true for research focused on the evaluation of adaptive forest management strategies. In this study, we developed an application, Climate AP, to generate scale-free(i.e., specific to point locations) climate data for historical(1901–2015) and future(2011–2100)years and periods. Climate AP uses the best available interpolated climate data for the reference period 1961–1990 as baseline data. It downscales the baseline data from a moderate spatial resolution to scale-free point data through dynamic local elevation adjustments. It also integrates and downscales the historical and future climate data using a delta approach. In the case of future climate data, two greenhouse gas representative concentration pathways(RCP 4.5 and 8.5) and 15 general circulation models are included to allow for the assessment of alternative climate scenarios. In addition, Climate AP generates a large number of biologically relevant climate variables derived from primary monthly variables. The effectiveness of the local downscaling was determined based on the strength of the local linear regression for the estimate of lapse rate. The accuracy of the Climate AP output was evaluated through comparisons of Climate AP output against observations from 1805 weather stations in the Asia Pacific region. The local linear regression explained 70%–80% and 0%–50% of the total variation in monthly temperatures and precipitation, respectively, in most cases. Climate AP reduced prediction error by up to27% and 60% for monthly temperature and precipitation,respectively, relative to the original baselines data. The improvements for baseline portions of historical and futurewere more substantial. Applications and limitations of the software are discussed.Tongli WANG Guangyu WANG John L.INNES Brad SEELY Baozhang CHEN 2017Frontiers of Agricultural Science and Engineering2017,4,4:22
3内蒙古草原挥发性有机物排放通量的研究显示文摘2 0 0 2年夏季 ,利用静态箱方法 ,对我国内蒙古草原生态系统挥发性有机物的排放进行了首次测量 ,同时观测了太阳辐射、温湿度等参数 .结果表明 ,异戊二烯是草地挥发性有机物排放中的主要成分 .异戊二烯的排放有明显的日变化、逐日变化和季节变化规律 .因子分析表明 ,可见光辐射、温度、水汽含量是影响异戊二烯排放的主要因子 ,而且可见光辐射是控制其排放过程的最主要因子 .根据相关分析 ,在考虑影响异戊二烯的排放因子时 ,不仅要考虑通常的影响因子———可见光辐射、温度 ,还要考虑水汽的作用 .箱方法的使用不可避免地造成箱内外太阳辐射、温湿度等的差别 ,因此 ,必须考虑修正采样箱对挥发性有机物排放通量带来的影响 .2 0 0 2年夏季 ,异戊二烯排放通量 (C)的最大值为 1 6 4 9 3μg/ (m2 ·h) .6、8、9月采样期间异戊二烯排放通量的日平均值分别为 886 6、70 7 0、4 2 7 2 μg/ (m2 ·h) .白建辉 王庚辰 任丽新 Brad Baker Patrick Zimmerman 梁宝生 2003环境科学2003,24,6:21
4内蒙古草原典型草地异戊二烯的排放特征显示文摘为准确了解内蒙古草原典型草地异戊二烯的排放状况 ,在 2 0 0 2和 2 0 0 3年观测实验的基础上 ,利用已有的经验模式和观测资料 ,计算了羊草样地 2 0 0 2和 2 0 0 3年生长季节异戊二烯的排放通量 .结果表明 :2 0 0 2和 2 0 0 3年异戊二烯排放具有明显的日、逐日、月、年变化 ,其排放通量首先依赖于可见光辐射 ,其次是温度 .2 0 0 2和 2 0 0 3年生长季羊草样地异戊二烯总排放 (以C计 )分别为 1 10 ,1 0 0g·m- 2 ,2 0 0 3年比 2 0 0 2年减少9 0 % .此现象主要是由于 2 0 0 3年可见光辐射减弱和气温降低造成的 .2 0 0 2和 2 0 0 3年生长季排放通量的最大值 (以C计 )分别为 2 3 3 2 0和193 3 8μg·m- 2 ·h- 1 ,当可见光辐射小时累计值小于 0 4MJ·m- 2 时 。白建辉 Brad Baker 2005环境科学学报2005,25,3:20
5草地异戊二烯排放通量影响因子的研究显示文摘20 0 2年夏季对中国内蒙古草原挥发性有机物的排放通量进行的首次测量结果表明 ,其主要成分异戊二烯的排放有明显的日变化和季节变化。采样箱对太阳辐射有非常明显的衰减作用 ,其衰减率为 1 7%~ 35 %。为准确估算异戊二烯的排放通量 ,建立其排放模式是非常必要的。基于可见光辐射传输与守恒的观点 ,在观测数据的基础上建立了异戊二烯排放通量的经验模式。结果表明 ,对日变化、季节变化和日总量的模拟值与测量值比较一致。在使用箱方法时 ,应该考虑箱内外辐射、温湿度、水汽含量之差引起的排放通量的差别 ,特别是箱内外辐射之差所引起排放通量的差别。同时也说明 ,可见光辐射是影响异戊二烯排放的最主要因子。利用异戊二烯排放通量的日总量与 1 1 :0 0通量之比和可见光辐射日总量与 1 1 :0 0时累计值之比的定量关系 ,可以由某日 1 1 :0 0的排放通量来推算该日的日总量 ,其平均相对偏差小于 1 4%。白建辉 Brad Baker 2004大气科学2004,28,5:19
6深圳市显著排放VOCs的园林植物调查与分析显示文摘对深圳地区的主要园林树种、地带性植被的代表种共计158种植物释放的生物源的挥发性有机物(biogenic volatileorganic compounds,BVOCs)采用流动式、封闭式采样法采样,运至美国进行GC-MS分析测量.结果表明,短穗鱼尾葵(Caryotamitis)、海红豆(Adenanthera pavonina var.microsperma)、杧果(Mangifera indica)、海漆(Excoecoria agalloch)等31种植物具有释放异戊二烯的能力;另有鸡蛋果(Passiflora edulis)、小琴丝竹(Bambusa glaucescens cv.silverstripe)、山苍子(Litsea cubeba)、大型双子铁(Dioon spinulosum)等52种植物具有释放单萜烯类化合物的能力.对红树植物的测量表明,该类植物普遍具有释放单萜烯的能力.上述结果为建立深圳及周边地区的环境质量模型提供了重要数据,同时也可为我国热带亚热带城市大面积绿化以及经济林、生态林和防护林等的树种选择提供参考.黄爱葵 李楠 Alex Guenther Jim Greenberg Brad Baker Michael Graessli 白建辉 2011环境科学2011,32,12:16
7Endoscopy and polyps-diagnostic and therapeutic advances in management显示文摘Despite multiple efforts aimed at early detection through screening, colon cancer remains the third leading cause of cancer-related deaths in the United States, with an estimated 51000 deaths during 2013 alone. The goal remains to identify and remove benign neoplastic polyps prior to becoming invasive cancers. Polypoid lesions of the colon vary widely from hyperplastic, hamartomatous and inflammatory to neoplastic adenomatous growths. Although these lesions are all benign, they are common, with up to one-quarter of patients over 60 years old will develop pre-malignant adenomatous polyps. Colonoscopy is the most effective screening tool to detect polyps and colon cancer, although several studies have demonstrated missed polyp rates from 6%-29%, largely due to variations in polyp size. This number can be as high as 40%, even with advanced (> 1 cm) adenomas. Other factors including sub-optimal bowel preparation, experience of the endoscopist, and patient anatomical variations all affect the detection rate. Additional challenges in decision-making exist when dealing with more advanced, and typically larger, polyps that have traditionally required formal resection. In this brief review, we will explore the recent advances in polyp detection and therapeutic options.Scott R Steele Eric K Johnson Bradley Champagne Brad Davis Sang Lee David Rivadeneira Howard Ross Dana A Hayden Justin A Maykel 2013World Journal of Gastroenterology2013,19,27:16
8From filaments to function: The role of the plant actin cytoskeleton in pathogen perception,signaling and immunity显示文摘The eukaryotic actin cytoskeleton is required for numerous cellular processes, including cell shape, development and movement, gene expression and signal transduction, and response to biotic and abiotic stress. In recent years,research in both plants and animal systems have described a function for actin as the ideal surveillance platform, linking the function and activity of primary physiological processes to the immune system. In this review, we will highlight recent advances that have defined the regulation and breadth of function of the actin cytoskeleton as a network required for defense signaling following pathogen infection. Coupled with an overview of recent work demonstrating specific targeting of the plant actin cytoskeleton by a diversity of pathogens,including bacteria, fungi and viruses, we will highlight the importance of actin as a key signaling hub in plants, one that mediates surveillance of cellular homeostasis and the activation of specific signaling responses following pathogen perception. B4 ased on the studies highlighted herein, we propose a working model that posits changes in actin filament organization is in and of itself a highly specific signal, which induces, regulates and physically directs stimulus-specific signaling processes, most importantly, those associated with response to pathogens.Katie Porter Brad Day 2016Journal of Integrative Plant Biology2016,58,4:12
9The BK channel:a vital link between cellular calcium and electrical signaling显示文摘Large-conductance Ca^(2+)-activated K+channels(BK channels)constitute an key physiological link between cellular Ca^(2+) signaling and electrical signaling at the plasma membrane.Thus these channels are critical to the control of action potential firing and neurotrans-mitter release in several types of neurons,as well as the dynamic control of smooth muscle tone in resis-tance arteries,airway,and bladder.Recent advances in our understanding of K^(+) channel structure and function have led to new insight toward the molecular mecha-nisms of opening and closing(gating)of these chan-nels.Here we will focus on mechanisms of BK channel gating by Ca^(2+),transmembrane voltage,and auxiliary subunit proteins.Brad S.Rothberg 2012Protein & Cell2012,3,12:9
10不同类型草地挥发性有机物排放特征的研究显示文摘2003年9月,对内蒙古草原不同类型草地挥发性有机物(VOC)的排放、太阳辐射、气象参数等进行观测,结果表明,固定和新的羊草样地、封育样地、不同程度放牧样地异戊二烯、α蒎烯、β蒎烯、柠檬烯、蒈烯的排放均有明显的日变化规律,并与可见光辐射以及温度有较好的一致性。羊草样地、封育样地、过度放牧、适度放牧样地异戊二烯排放的最大值分别为139.5、25.9、132.3、107.1(单位:μg.m-2.h-1,以碳计)。多数情况下,异戊二烯排放通量的测定结果为羊草样地高于封育样地、过度放牧样地高于适度放牧样地。不同程度放牧样地α蒎烯、β蒎烯、柠檬烯、蒈烯等的排放具有明显差别,一般是过度放牧草地高于适度放牧草地。剪草增大了绝大部分VOC组分的排放、以及过度和适度放牧草地VOC的排放,剪草可以造成过度和适度放牧草地异戊二烯排放在中午前后的增加。剪草后,过度放牧草地异戊二烯、α蒎烯、β蒎烯、柠檬烯、蒈烯等的排放通量均远大于适度放牧草地的相应值。土壤异戊二烯、α蒎烯、β蒎烯等的排放很小,分别占相近可见光辐射和温度条件下固定羊草样地排放的0.2%、0、3.0%。白建辉 Brad Baker 2006大气科学2006,30,1:9
11Modern imaging of the tracheo-bronchial tree显示文摘Recent state-of-the-art computed tomography and improved three-dimensional(3-D) postprocessing techniques have revolutionized the capability of visualizing airway pathology,offering physicians an advanced view of pathology and allowing for appropriate management planning.This article is a comprehensive review of trachea and main bronchi imaging,with emphasis on the dynamic airway anatomy,and a discussion of a wide variety of diseases including,but not limited to,congenital large airway abnormalities,tracheobronchial stenoses,benign and malignant neoplasms and tracheobronchomalacia.The importance of multiplanar reconstruction,3-D reconstruction and incorporation of dynamic imaging for non-invasive evaluation of the large airways is stressed.Archana T Laroia Brad H Thompson Sandeep T Laroia Edwin JR van Beek 2010World Journal of Radiology2010,2,7:8
12两种快速检测西尼罗病毒方法的研究显示文摘目的建立可用于中国的蚊虫携带西尼罗病毒(WNV)监测的快速检测方法。方法选择两种快速检测方法VecTest试剂盒和Ramp系统,对其检测WNV的敏感性、精确性以及与流行性乙型脑炎(乙脑)病毒的交叉反应进行研究,同时对采自北京市野外的蚊虫进行WNV检测。结果Ramp试剂盒检测方法比VecTest试剂盒方法敏感性高,但后者检测时间短、操作简便,更适合现场筛查使用;经RT-PCR方法确认此2种快速检测方法无假阳性及假阴性结果;VecTest试剂盒和Ramp系统与乙脑病毒也无交叉反应。使用这2种检测方法对北京市6种野外蚊虫进行了WNV检测,结果均为阴性。结论VecTest试剂盒和Ramp系统均可用于WNV快速检测。佟颖 曾晓芃 刘婷 肖萧 朱俊伟 Brad Tucker 2006中国媒介生物学及控制杂志2006,17,4:8
13基于GPC和FTIR的再生混合料新旧沥青融合程度研究显示文摘伴随着沥青路面回收料(RAP)在沥青路面修筑和维护中的逐步推广应用,有关RAP对再生路面结构及其力学性能的影响已有了大量的研究,但对RAP旧沥青和新沥青的融合问题还尚不清楚。工程应用中通常假定RAP旧沥青与新沥青发生了完全融合。但如果两者没有完全融合,路面的使用寿命将小于预期水平。该文中,假定再生沥青混合料中集料表面各沥青层可独立完全地分离出来,在此前提下,研究中对再生沥青混合料进行了分层萃取,并利用凝胶渗透色谱(GPC)和傅立叶转换红外光谱(FTIR)对分层萃取出的各层沥青进行定量检测,经对比分析后确定RAP旧沥青和新沥青的融合程度。研究结果表明:再生沥青混合料中RAP表面各层旧沥青与新沥青均发生了一定程度的融合。张德鹏(编译) 徐金枝(编译) 郝培文(编译) benjamin f.bowers baoshan huang xiang shu brad c.miller 2016中外公路2016,36,6:8
14Overhanging rock slope by design:An integrated approach using rock mass strength characterisation,large-scale numerical modelling and limit equilibrium methods显示文摘Overhanging rock slopes(steeper than 90°) are typically avoided in rock engineering design, particularly where the scale of the slope exceeds the scale of fracturing present in the rock mass. This paper highlights an integrated approach of designing overhanging rock slopes where the relative dimensions of the slope exceed the scale of fracturing and the rock mass failure needs to be considered rather than kinematic release of individual blocks. The key to the method is a simplified limit equilibrium(LE) tool that was used for the support design and analysis of a multi-faceted overhanging rock slope. The overhanging slopes required complex geometries with constantly changing orientations. The overhanging rock varied in height from 30 m to 66 m. Geomechanical modelling combined with discrete fracture network(DFN)representation of the rock mass was used to validate the rock mass strength assumptions and the failure mechanism assumed in the LE model. The advantage of the simplified LE method is that buttress and support design iterations(along with sensitivity analysis of design parameters) can be completed for various cross-sections along the proposed overhanging rock sections in an efficient manner, compared to the more time-intensive, sophisticated methods that were used for the initial validation. The method described presents the development of this design tool and assumptions made for a specific overhanging rock slope design. Other locations will have different geological conditions that can control the potential behaviour of rock slopes, however, the approach presented can be applied as a general guiding design principle for overhanging rock cut slope.Paul Schlotfeldt Davide Elmo Brad Panton 2018Journal of Rock Mechanics and Geotechnical Engineering2018,10,1:8
15Application of Cydia pomonella expressed sequence tags: Identification and expression of three general odorant binding proteins in codling moth显示文摘幼鳕蛾, Cydia pomonella,是在世界上的梨果水果的最重要的害虫之一,然而,分子的遗传和这个昆虫遗体的生理学糟糕理解。8341 个表示顺序标签的一个联合集会从八个织物特定的 cDNA 图书馆定序的 Roche 454 GS-FLX 被产生。通常认为的化学感应的蛋白质(12 ) 和有气味的东西绑定蛋白质(OBP )(18 ) 被注解,它包括了三通常认为的一般 OBP (GOBP ) ,一个人典型地非常为另外的鳞翅目报导了。为了推进,描绘 CpomGOBPs,我们克隆他们的抄本的 cDNA 拷贝并且在各种各样的纸巾决定了他们的表示模式。为 CpomGOBP1 698nt 抄本克隆并且定序导致了编码区域的 163 氨基酸的预言,并且随后的 RT-PCR 显示抄本主要在天线和 mouthparts 被表示。CpomGOBP3 抄本主要是的 702 nt (169 氨基酸) 在天线, mouthparts,和女腹部表示了的 CpomGOBP2 和小说付小费给的 1289 nt (160 氨基酸) 。这些结果显示定序的那下一代为兴趣的新奇抄本的鉴定是有用的,并且那幼鳕蛾表示为 GOBP 亚科的一个新成员编码的一个抄本。Stephen F. Garczynski Brad S. Coates Thomas R. Unruh Scott Schaeffer Derick Jiwan Tyson Koepke Amit Dhingra 2013Insect Science2013,20,5:6
16The complexity of sediment recycling as revealed by common Pb isotopes in K-feldspar显示文摘Detrital zircon U-Pb geochronology has become the gold standard in evaluating source to sink relationships in sedimentary basins. However, the physical and chemical robustness of zircon, which make it such a useful mineral for provenance studies, is also a hindrance as zircon can be recycled through numerous sedimentary basins, thus obscuring the first cycle source to sink relationship. An elegant approach to addressing this potential issue is to compare the Pb isotope composition of detrital K-feldspar, a mineral which is unlikely to survive more than one erosion-transport-deposition cycle, with that of magmatic K-feldspar from potential basement source terranes. Here we present new in situ Pb isotope data on detrital K-feldspar from two Proterozoic arkosic sandstones from Western Australia, and magmatic K-feldspar grains from potential igneous source rocks, as inferred by the age and Hf isotope composition of detrital zircon grains. The data indicate that the detrital zircon and K-feldspar grains could not have been liberated from the same source rocks, and that the zircon has most likely been recycled through older sedimentary basins. These results provide a more complete understanding of apparently simple source to sink relationships in this part of Proterozoic Western Australia.Simon P.Johnson Christopher L.Kirkland Noreen J.Evans Brad J.McDonald Huntly N.Cutten 2018Geoscience Frontiers2018,9,5:5
17The Early-Middle Pleistocene Transition: characterization and proposed guide for the defining boundary显示文摘Martin J. Head Brad Pillans Sarah A. Farquhar 2008Episodes2008,31,2:5
18Discussions on rockburst and dynamic ground support in deep mines显示文摘The paper is a summary of discussions on four topics in rockburst and dynamic ground support.Topic 1 is the mechanisms of rockburst.Rockburst events are classified into two categories in accordance with the triggering mechanisms,i.e.strain burst and fault-slip burst.Strain burst occurs on rock surfaces when the tangential stress exceeds the rock strength in hard and brittle rocks.Fault-slip burst is triggered by fault-slip induced seismicity.Topic 2 is prediction and forecasting of rockburst events.Prediction for a rockburst event must tell the location,timing and magnitude of the event.Forecasting could simply foresee the probability of some of the three parameters.It is extremely challenging to predict rockbursts and large seismic events with current knowledge and technologies,but forecasting is possible,for example the possible locations of strain burst in an underground opening.At present,the approach using seismic monitoring and numerical modelling is a promising forecasting method.Topic 3 is preconditioning methods.The current preconditioning methods are blasting,relief-hole drilling and hydrofracturing.Defusing fault-slip seismicity is difficult and challenging but has been achieved.In very deep locations(>3000 m),the fracturing could extend from the excavation face to a deep location ahead of the face and therefore preconditioning is usually not required.Topic 4 is dynamic ground support against rockburst.Dynamic ground support requires that the support system be strong enough to sustain the momentum of the ejecting rock on one hand and tough enough on the other hand to absorb the strain and seismic energies released from the rock mass.The current dynamic support systems in underground mining are composed of yielding tendons and flexible surface retaining elements like mesh/screen and straps.Yielding props and engineered timber props are also used for dynamic support.Charlie C.Li Peter Mikula Brad Simser Bruce Hebblewhite William Joughin Xiaowei Feng Nuwen Xu 2019Journal of Rock Mechanics and Geotechnical Engineering2019,11,5:5
19Discovery of nigral dopaminergic neurogenesis in adult mice显示文摘Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra. As a result, intensive efforts have focused upon mechanisms that facilitate the death of mature dopaminergic neurons. Unfortunately, these efforts have been unsuccessful in providing an effective treatment to address neurodegeneration in this disease. Therefore, alternative theories of pathogenesis are being explored. Adult neurogenesis of dopaminergic neurons is an attractive concept that would provide a possible mechanism of neurodegeneration as well as offer an endogenous means to replenish affected neurons. To determine whether dopaminergic neurons experience neurogenesis in adult mice we developed a novel cell lineage tracing model that permitted detection of neurogenesis without many of the issues associated with popular techniques. Remarkably, we discovered that dopaminergic neurons are replenished in adult mice by Nestin+/Sox2- progenitor cells. What's more, the rate of neurogenesis is similar to the rate of dopaminergic neuron loss reported using a chronic, systemic inflammatory response mouse model. This observation may indicate that neuron loss in Parkinson's disease results from inhibition of neurogenesis.Brad E.Morrison 2016Neural Regeneration Research2016,11,6:5
20The Patatin-Containing Phospholipase A pPLAIIα Modulates Oxylipin Formation and Water Loss in Arabidopsis thaliana显示文摘patatin 相关的 phospholipase A (pPLA ) 水解膜 glycerolipids 将生产 monoacyl 混合物和免费的丰满的酸。Phospholipids 被 pPLAII 在 sn-1 和 sn-2 劈开包括那些包含的 oxophytodienoic 酸,位置,和 galactolipids 能也用作底层。pPLAII 的脱离减少了 lysophosphatidylcholine 和 lysophosphatidylethanolamine 层次,而是增加的免费的亚麻酸的酸。pPLAII 缺乏的植物显示了 jasmonic 酸和甲基的高水平 jasmonate,以及 oxylipin-biosynthetic 中介 13-hydroperoxylinolenic 酸和比酸的 12-oxophytodienoic 野类型(WT ) 植物。涉及 oxylipin 生产的基因的表示比在 WT 植物在 pPLAII 缺乏的异种也是更高的。变异的植物比 WT 植物更快速失去了水。WT 和变异的植物的 stomata 对 abscisic 酸同样作出回应。响应干燥,异种和 WT 叶子以一样的率生产了 abscisic 酸,,但是,在干燥的 4h 以后, jasmonic 酸水平比 WT 离开的在异种是高得多的。这些结果显示 pPLAII 否定地调整 oxylipin 生产并且从膜在氧化地修改的丰满的酸的移动建议一个角色。Wen-Yu Yang Yong Zheng Sung Chul Bahn Xiang-Qing Pan Mao-Yin Li Hieu Sy Vu Mary R.Roth Brad Scheu Ruth Welt Yue-Yun Hong Xue-Min Wang 2012Molecular Plant2012,5,2:5
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