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Modeling and Simulation on Signatures of Mars Minerals 火星矿物特征的建模与模拟
Pub Date : 2010-01-01 DOI: 10.25778/AFR9-8X35
W. Elmahboub, Edward Yankey, Olivia Kerwin
The objective of this study was to assess the feasibility of identiying minerals on Mars using remotely sensed data. In the process we also investigated the effect of noise of aerosol and dust particles on the spectra of Mars minerals. The remotely sensed data was obtained through modeling and simulation and compared to the lab spectroscopy of the specific minerals in order to make an accurate identification. A linear model was developed using MATLAB Random Number Generator to obtain a simulated image. Part of the information we needed for the linear model was pure pixel information of Mars which was obtained from Mars Spirit images. Random noise was added to the image in order to simulate a real world image. In addition to the random noise, a mathematical model was developed to represent the noise caused by aerosols and dust particles in Mars’s atmosphere. The simulation was tested to ensure that it satisfied the appropriate model testing. Our results showed that our linear model was appropriate, and was accepted at a confidence interval of about 95%. The simulated image was then corrected from noise through iterations. The overall accuracy of the corrected image showed an improvement in classification by 25%. The signatures of the spectra of the two images were obtained and compared to the lab spectroscopy of specific minerals. The degradation of noise showed improvement in the spectral analysis of Mars data. The spectral analysis showed the presence of iron oxide, calcium oxide and magnesium oxide leading to the conclusion that the image simulation is reliable in mineral spectral identification.
这项研究的目的是评估利用遥感数据查明火星上矿物的可行性。在此过程中,我们还研究了气溶胶和尘埃颗粒噪声对火星矿物光谱的影响。通过建模和模拟获得遥感数据,并与特定矿物的实验室光谱进行比较,以便进行准确的识别。利用MATLAB随机数生成器建立线性模型,得到仿真图像。线性模型需要的部分信息是火星的纯像素信息,这些信息来自火星勇气号图像。为了模拟真实世界的图像,在图像中加入了随机噪声。除了随机噪声外,还建立了一个数学模型来表示火星大气中气溶胶和尘埃颗粒引起的噪声。对仿真进行了测试,以确保其满足适当的模型测试。我们的结果表明,我们的线性模型是合适的,并且在约95%的置信区间内被接受。然后通过迭代对模拟图像进行噪声校正。校正后的图像的总体准确率提高了25%。获得了两幅图像的光谱特征,并与特定矿物的实验室光谱进行了比较。噪声的降低表明火星数据的光谱分析有所改善。光谱分析表明,该矿物中存在氧化铁、氧化钙和氧化镁,因此图像模拟在矿物光谱识别中是可靠的。
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引用次数: 0
First Records of Hypleurochilus geminatus and Centropristis philadelphica from Chesapeake Bay 标题切萨皮克湾双棱棘蝽和费城中部棘蝽的首次记录
Pub Date : 2009-01-01 DOI: 10.25778/D7FW-1P42
A. D. Halvorson
During the fall of 2007, Centropristis philadelphica (rock seabass) and Hypleurochilus geminatus (crested blenny) were collected from Chesapeake Bay. These captures are significant as they represent the first substantiated record of C. philadelphica from Chesapeake Bay and only the second and third validated records of H. geminatus. Additionally, the first record of H. geminatus from Chesapeake Bay was only recently recognized since the specimen had been previously misidentified as Parablennius marmoreus (seaweed blenny). The collection of seven individuals of H. geminatus in 2007, from two locations, indicates that the species may be resident within the Chesapeake Bay estuary. INTRODUCTION The Chesapeake Bay, an ecotone between the Atlantic Ocean and the rivers of Maryland and Virginia, experiences extreme seasonal temperature changes and contains a range of habitats. Species richness is typical of such ecological systems and is evident by the estuary’s diverse and dynamic fish fauna, which includes permanent residents, spawning migrants, and seasonal visitors (Murdy et al. 1997). The fish fauna of Chesapeake Bay has been surveyed extensively since the early 1900’s (Hildebrand and Schroeder 1928; Massman 1962; Massman and Mansueti 1963; Musick 1972; Murdy et al. 1997) yet warmwater species uncommon to the estuary continue to be encountered (Halvorson 2007). Two such species, Centropristis philadelphica (rock seabass) and Hypleurochilus geminatus (crested blenny), were collected in Chesapeake Bay during the fall of 2007 by the Virginia Institute of Marine Science (VIMS) Juvenile Fish and Blue Crab Trawl Survey. MATERIALS AND METHODS Five-minute bottom tows were conducted in lower Chesapeake Bay with a 9.14 m otter trawl (38.11 mm stretched mesh body, 6.35 mm cod-end liner, and a tickler chain) off the 8.5 m R/V Fish Hawk. Fish were identified and measured to the nearest mm (total length for H. geminatus and total length centerline for C. philadelphica). Voucher specimens were deposited in the Ichthyological Collection, Virginia Institute of Marine Science, Gloucester Point, Virginia (H. geminatus-VIMS 11776, C. philadelphicaVIMS 11979). Hydrological measurements (water temperature, salinity) were taken with a YSI 600Q (YSI Incorporated, Yellow Springs, Ohio). Virginia Journal of Science Volume 60, Number 3 Fall 2009 (804) 684-7751, aimeehal@vims.edu 1 142 VIRGINIA JOURNAL OF SCIENCE RESULTS On September 6 , 2007, five individuals of H. geminatus (39-78 mm) were th captured in Chesapeake Bay at 37o17.13’N, 76o 03.11’W, near Cape Charles, Virginia (Figure 1; Table 1). Water depth at this station was 7 m and the bottom water temperature and salinity were 26.59oC and 23.64‰, respectively. Two additional specimens (34-37 mm) were collected on November 14 , 2007, at 36o58.43’N, th 76o16.59’W, near the entrance to Hampton Roads, in 5.5 m of water (Figure 1; Table 1). The bottom water temperature was 13.63oC and bottom salinity was 22.79‰. A single speci
2007年秋天,在切萨皮克湾收集了费城中部海鲈(岩鲈)和双头海鲈(凤头海鲈)。这些捕获具有重要意义,因为它们代表了切萨皮克湾第一份得到证实的费城蠓记录,而只有第二和第三份得到证实的双子座蠓记录。此外,在切萨皮克湾发现的第一个双尾海带记录直到最近才被确认,因为该标本之前被错误地识别为Parablennius marmoreus(海藻混合)。2007年在两个地点采集到的7只双尾海星表明该物种可能居住在切萨皮克湾河口。切萨皮克湾是大西洋与马里兰州和弗吉尼亚州河流之间的过渡带,经历了极端的季节性温度变化,并包含一系列栖息地。物种丰富度是这类生态系统的典型特征,河口的鱼类动物群多样性和动态特征很明显,包括永久居民、产卵洄游者和季节性游客(Murdy et al. 1997)。自20世纪初以来,切萨皮克湾的鱼类动物群已被广泛调查(Hildebrand and Schroeder 1928;Massman 1962;Massman and Mansueti 1963;Musick 1972;Murdy et al. 1997),然而在河口不常见的暖水物种仍然存在(Halvorson 2007)。2007年秋天,弗吉尼亚海洋科学研究所(VIMS)的幼鱼和蓝蟹拖网调查在切萨皮克湾收集了两个这样的物种:费城石鲈(Centropristis philphilica)和双头海鲈(Hypleurochilus geminatus)。材料和方法在切萨皮克湾下游,使用9.14米的水獭拖网(38.11毫米拉伸网体,6.35毫米渔尾衬垫和挠痒链)从8.5米的R/V鱼鹰号进行5分钟的海底拖网。鱼类的鉴定和测量精确到毫米(双尾鱼的全长和费城鱼的全长中心线)。代金券标本保存在弗吉尼亚州格洛斯特角弗吉尼亚海洋科学研究所鱼类学馆藏(H. geminatus-VIMS 11776, C. philphiladelphia avims 11979)。水文测量(水温、盐度)用YSI 600Q (YSI Incorporated, Yellow Springs, Ohio)进行。弗吉尼亚科学杂志2009年秋季第60卷第3期(804)684-7751,aimeehal@vims.edu 1 142弗吉尼亚科学杂志结果2007年9月6日,在弗吉尼亚州查尔斯角附近的切萨皮克湾,在37o17.13'N, 76o 03.11'W,捕获了5只长39-78毫米的双尾圆尾鱼(图1;表1).该站水深7 m,底层水温26.59oC,盐度23.64‰。2007年11月14日,在汉普顿路入口附近5.5米深的水中,在北纬36o58.43度,西经76o16.59度处采集了另外两个标本(34-37毫米)(图1;表1).海底水温13.63oC,海底盐度22.79‰。2007年11月5日,在切萨皮克湾大桥隧道第一条隧道上游约1公里处,在北纬36o58.76度,西经76o07.16度处采集到单株费城杉(210毫米)标本(图1;表1)水深13.4 m,底部水温17.22oC,盐度24.54‰。讨论:凤头螺(Hypleurochilus geminatus)是一种亚热带物种,通常与牡蛎礁、壳底相联系(Dahlberg 1972;Crabtree and midaugh 1982;Lehnert and Allen 2002),以及附着在桩子和岩石上的海洋生物(Hildebrand and Cable 1938)。它们以自由游动的生物和无根生物为食(图1)。2007年在切萨皮克湾采集费城中部棘球蚴(" ")和1993年和2007年在切萨皮克湾采集双叶棘球蚴(Ä)。CHESAPEAKE BAY FISH 143生长(Hildebrand and Cable 1938),其饮食主要由甲壳类动物和藻类组成,其次是水螅类和多毛类(Lindquist and Chandler 1978;Lindquist and Dillaman 1986)。Hildebrand和Cable(1938)确定,北卡罗莱纳双叶蠓的产卵时间为5 - 9月,幼虫主要在水面栖息,直到体长10- 15mm,此时它们改变了栖息地偏好。在他们的研究中收集到的最大的鱼是72毫米的雄鱼,最大的雌鱼是58毫米(Hildebrand and Cable 1938)。虽然双子星鱼的分布范围包括新泽西州到佛罗里达州东部中部海岸的水域(Williams 2002),但北卡罗来纳州以北的唯一集合只在新泽西州附近零星发生(Fowler 1914;Allen et al. 1978;可以1992;Able and Fahay, 1998)。在早期对弗吉尼亚水域,包括切萨皮克湾及其支流的研究中,没有报道过双叉棘鱼(Hildebrand and Schroeder 1928;Massman 1962;Massman and Mansueti 1963;Musick 1972;Murdy等人。 1997年)和海岸和入海口(Schwartz 1961;Richards和Castagna 1970;Cowan and Birdsong 1985;Norcross and Hata 1990;2000年门外汉)。Ditty et al.(2005)错误地报道了Hildebrand和Cable(1938)从切萨皮克湾获得的双叶蛾幼虫。正在进行的全海湾调查,包括切萨皮克湾多物种监测和评估计划(ChesMMAP)(詹姆斯·加特兰,弗吉尼亚海洋科学研究所,格洛斯特角,弗吉尼亚州,个人交流)和切萨皮克湾渔业独立多物种调查(CHESFIMS)(米勒和洛温斯坦纳2008),尚未遇到这种物种。切萨皮克湾的标本也不存在于VIMS鱼类学收藏或美国国家博物馆(USNM)鱼类收藏中(L. Palmer, Smithsonian Institution, pers)。通讯)。2007年的捕获并不是在切萨皮克湾收集到的第一次双爪蜥记录。Murdy等(1997)报道了1993年6月捕获的一种Parablennius marmoreus(海带)标本(VIMS标本09086)。根据表1。物种表,显示标本数量、采集年份和采集地点(经纬度)。物种年份标本数量经纬度费城centrropristis philphilica 2007 1 36o58.76N 76o07.16W混血人(Hypleurochilus geminatus, Murdy et al. 1997报道为Parablennius marmoreus) 1993 1 37o16.63N 76o03.43W混血人(Hypleurochilus geminatus) 2007 5 37o17.13N 76o03.11W混血人(Hypleurochilus geminatus) 2007 2 36o58.43N 76o16.59W 144 VIRGINIA JOURNAL of SCIENCE 2007年进一步鉴定,确定该标本曾被误鉴定,确实是混血人。有趣的是,该标本采集于37o16.63'N, 76o03.43'W(图1;表1),于2007年9月收集5只个体的地点1公里范围内。1993年,人们在切萨皮克湾首次发现了一只被误认的双髻
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引用次数: 1
Management and Social Indicators of Soil Carbon Storage in a Residential Ecosystem, Midlothian, VA 住宅生态系统土壤碳储量的管理与社会指标,米德洛西安,弗吉尼亚州
Pub Date : 2009-01-01 DOI: 10.25778/NMD5-XX86
C. Gough, Elizabeth A. Fritz
Soil carbon storage - defined here as carbon mass per unit ground area - is an important ecosystem service, sequestering carbon that might otherwise exist 2 in atmospheric CO . Significant attention has focused on the effects that humans have on carbon cycling, but little is known about how human behaviors and attitudes relate to lawn carbon storage. The objectives of this study were to conduct household surveys in concert with soil carbon sampling in a 10-yr-old exurban neighborhood near Richmond, Virginia to quantify differences in soil carbon storage between residential lawns and mixed pinehardwood forest fragments, and to determine how lawn management and environmental attitudes relate to soil carbon storage. Lawns stored significantly less carbon than forest fragments in the top 10 cm of soils. A significant negative relationship was observed between watering and fertilizer frequency and soil carbon storage, but the goodness-of-fit was sensitive to intra-lawn variability in soil carbon mass. Survey respondents that claimed to be environmentalists stored significantly more carbon and spent one hour less per week managing their lawns, suggesting that environmental attitudes may affect how households manage their lawns and, in turn, the quantity of soil carbon stored in residential soils.
土壤碳储量——这里定义为每单位地面面积的碳质量——是一项重要的生态系统服务,将原本可能存在于大气CO中的碳封存起来。人类对碳循环的影响一直备受关注,但人类的行为和态度与草坪碳储存的关系却鲜为人知。本研究的目的是在弗吉尼亚州里士满附近的一个10年历史的郊区社区进行家庭调查,并进行土壤碳采样,以量化住宅草坪和混合松木林碎片之间土壤碳储量的差异,并确定草坪管理和环境态度与土壤碳储量的关系。草坪在土壤顶部10厘米处储存的碳明显少于森林碎片。水肥频率与土壤碳储量呈显著负相关,但拟合优度对草地内土壤碳质量变异敏感。自称是环保主义者的调查受访者储存了更多的碳,每周花在管理草坪上的时间少了一个小时,这表明环保态度可能会影响家庭管理草坪的方式,进而影响住宅土壤中储存的土壤碳量。
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引用次数: 1
Seasonal Variation in Diet of a Marginal Population of the Hispid Cotton Rat, Sigmodon hispidus 毛棉大鼠边缘种群日粮的季节变化
Pub Date : 2009-01-01 DOI: 10.25778/RQWG-EN57
Lynn A. Walker, R. K. Rose
Cotton rats live in oldfields, habitats with a variety of mostly herbaceous plants. Based on other studies, the hispid cotton rat, Sigmodon hispidus, eats many kinds of herbaceous plants but grasses predominate. In contrast, our population of cotton rats ate many monocots but mostly they were not grasses. Our study sought to determine the diet of the cotton rat in eastern Virginia, near the northern limit of distribution on the Atlantic Coast. Fecal samples, collected each month during an on-going capture-mark-release demographic study of the rodent community, were analyzed using a standard method. A greater variety of foods (including insects) was eaten in the summer and autumn than in winter and spring. In winter, when much herbaceous vegetation is standing dead, cotton rats supplemented their diets with pine bark. Cotton rats ate significantly greater proportions of monocots in winter and spring, an apparent response to the need for more calories to compensate for greater heat loss. In summer and autumn, cotton rats enhanced their diets with significantly greater proportions of the more nutritious but harder to digest dicots. Reproductive females ate significantly more dicots and less monocots than males and non-reproductive females, whose diets were similar.
棉鼠生活在古老的田野里,那里有各种各样的草本植物。根据其他研究,棉鼠(Sigmodon hispidus)以多种草本植物为食,但以禾草为主。相比之下,我们的棉鼠种群吃很多单子叶植物,但它们大多不是草。我们的研究试图确定弗吉尼亚州东部棉花鼠的饮食,靠近大西洋海岸分布的北部界限。在正在进行的啮齿动物群落捕获-标记-释放人口统计研究中,每个月收集的粪便样本使用标准方法进行分析。与冬季和春季相比,夏季和秋季食用的食物(包括昆虫)种类更多。在冬天,当许多草本植物枯死时,棉鼠以松树皮作为补充。棉花大鼠在冬季和春季吃的单子叶的比例明显更高,这显然是对需要更多卡路里来补偿更多热量损失的反应。在夏季和秋季,棉花大鼠增加了更多营养丰富但难以消化的坚果的饮食比例。与饮食相似的雄性和非生殖雌性相比,有生殖能力的雌性吃更多的双子叶,吃更少的单子叶。
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引用次数: 4
Phytoplankton Blooms: Their Occurrence and Composition Within Virginia's Tidal Tributaries 浮游植物大量繁殖:它们在弗吉尼亚潮汐支流中的发生和组成
Pub Date : 2009-01-01 DOI: 10.25778/3KCS-7J11
H. Marshall, T. Egerton
Sporadic algal bloom development within a IO year monitoring program in Virginia tidal tributaries of Chesapeake Bay is reviewed. These blooms were common events, characteristically producing a color signature to the surface water, typically short lived, occurring mainly from spring into autumn throughout different salinity regions of these rivers. and were produced primarily by dinoflagcilatcs. The abundance threshold levels that would identify bloom status from a non-bloom presence were species specific, varied with the taxon's cell size, and ranged from ca. 10 to () cells ml • Among the most consistent sporadic bloom producers were the dinoflagcllatcs Akashiwo sanguinea, Cochlodinium polvkrikoides, Heterocapsa rotundata, Hetcrocapsa triquetra, Karlodinium l'eneficum, Prorocentrum minimum, Scrippsiella trochoidea, the cyanobacterium lvficrocystis aeruginosa, and two categories containing several species of often unidentified Gymnodinium spp. and Gyrodinium spp. Additional bloom producers within these tributaries arc also discussed.
本文回顾了切萨皮克湾弗吉尼亚潮汐支流50年监测项目中零星藻华的发展。这些水华是常见的事件,其特征是在地表水中产生一种颜色特征,通常是短暂的,主要发生在春季到秋季,遍布这些河流的不同盐度区域。主要是由鞭毛虫产生的。丰度阈值水平与非华的存在有物种特异性,随分类单元的细胞大小而变化,范围从10到10个细胞ml不等。最一致的偶发性华的产生者是dinoflagclclcs Akashiwo sanguinea, cochlordinium polvkrikoides, Heterocapsa rotundata, Hetcrocapsa triquetra, Karlodinium l'eneficum, proorocentrum minimum, Scrippsiella trochoidea, lvficrocystis aeruginosa,另外还讨论了在这些支流中产生花的其他植物。
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引用次数: 25
Graminicolous Fungi of Virginia: Fungi in Collections 2004-2007 弗吉尼亚禾本科真菌:真菌收藏2004-2007
Pub Date : 2009-01-01 DOI: 10.25778/DPBH-D446
C. W. Roane
Fungus-grass associations recognized in Virginia from 2004 to 2007 are recorded. Many associations are new to the United States (U), eastern United States (EU), and Virginia (V); other associations extend the known distribution of those previously discovered. These reports contribute further to knowledge of the mycoflora of Virginia.
记录了2004年至2007年在弗吉尼亚州确认的真菌-草协会。许多协会对美国(U),美国东部(EU)和弗吉尼亚州(V)都是新的;其他关联扩展了先前发现的已知分布。这些报告有助于进一步了解弗吉尼亚州的真菌菌群。
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引用次数: 7
A Standardized RNA Isolation Protocol for Yam (Dioscorea alata L) cDNA Library Construction 薯蓣(薯蓣)cDNA文库构建的标准化RNA分离方法
Pub Date : 2009-01-01 DOI: 10.25778/HY8W-M911
S. S. Narina, A. Mohamed, R. Asiedu, H. Mignouna
For the purpose of constructing yam cDNA libraries, attempts to isolate high quality RNA using several previously reported protocols were unsuccessful. Therefore a protocol was standardized for yam total RNA isolation by using guanidium buffer at the Department of Biology, Virginia Sate University. The RNA isolated using this standardized protocol was high in quality and led to successful good quality cDNA library construction and identification of functional ESTs in yam. INTRODUCTION Yam, (Dioscorea alata L), is the main food source for over 100 million people in humid and sub-humid tropics. Its production is affected by several biotic and abiotic factors (Abang et al., 2003). Anthracnose, caused by Colletotrichum gloeosporioides, is the most severe foliar disease of water yam (Dioscorea alata L) and is a major hurdle in yam production. It is reported that anthracnose causes yield reduction up to 90% (http://annualreport.iita.org). There are no cost effective control measures and the long-term solution to the problem will be through the development of resistant genotypes (Mignouna et al., 2002. Very limited yam sequence information is available from public genome databases. A review of previous efforts to develop cDNAs towards EST development in yams revealed that housekeeping genes were prevalent in the libraries constructed using total RNA from male flowers (Mignouna et al., 2002a, b, c). It is realized that obtaining high quality, intact RNA is the first and the most critical step in conducting cDNA library construction and for further analysis of gene of interest. After many attempts of total RNA isolations from yam leaf samples using standard plant RNA isolation protocols (Verwoerd et al,1989), only 6-10 ug of total RNA was extracted from the leaves and no colonies were observed when this RNA was used for cDNA library construction. The RNA appeared as a smear on 1.1% agarose gel (Fig. 1). The most likely reason for not getting good quality RNA is the mucilagenous tissue in yam plant parts like leaf, stem and tuber. This tissue causes problem because of polyphenols, polysaccharides and other secondary metabolites that are rich in yam plant parts and are not easily removed by conventional extraction methods. The aim of this study was to establish a protocol for RNA isolation from Dioscorea alata to get high quality and high quantity RNA that is suitable for generation of molecular markers, such as EST-SSRs and SNPs. Therefore, the following article discusses successful and reproducible method of RNA isolation Virginia Journal of Science Volume 60, Number 4 Winter 2009 172 VIRGINIA JOURNAL OF SCIENCE procedure employed for yam cDNA library constrcution and ways of increasing RNA yields MATERIALS AND METHODS Tissue collection: In order to standardize the protocol for RNA isolation, the yam (source: local grocery store) were grown in the green house in pots. Fresh 1g leaf tissues are collected in 50ml BD Falcon tubes, frozen quickly in liquid ni
为了构建山药cDNA文库,使用先前报道的几种方法分离高质量RNA的尝试都不成功。因此,弗吉尼亚州立大学生物系标准化了使用胍缓冲液分离山药总RNA的方案。利用该标准化方案分离的RNA质量高,并成功构建了高质量的cDNA文库和鉴定了山药的功能ESTs。山药(Dioscorea alata L)是湿润和半湿润热带地区1亿多人的主要食物来源。它的生产受到几种生物和非生物因素的影响(Abang et al., 2003)。炭疽病是由炭疽菌(Colletotrichum gloeosporioides)引起的水山药最严重的叶面病害,是山药生产的主要障碍。据报道,炭疽病导致产量降低高达90% (http://annualreport.iita.org)。没有具有成本效益的控制措施,长期解决问题的办法将是开发耐药基因型(Mignouna et al., 2002)。公共基因组数据库提供的山药序列信息非常有限。回顾了之前在番薯EST发育中开发cDNA的工作,发现管家基因在使用雄花总RNA构建的文库中普遍存在(Mignouna等人,2002a, b, c)。我们认识到,获得高质量、完整的RNA是进行cDNA文库构建和进一步分析感兴趣基因的第一步也是最关键的一步。在使用标准植物RNA分离方案(Verwoerd et al,1989)多次尝试从山药叶片样品中分离总RNA后,仅从叶片中提取了6-10 ug的总RNA,并且在将该RNA用于cDNA文库构建时未观察到菌落。在1.1%琼脂糖凝胶上出现了RNA涂片(图1)。无法获得高质量RNA的最可能原因是山药植物部分(如叶、茎和块茎)的粘液组织。这种组织会造成问题,因为多酚、多糖和其他次生代谢物富含山药植物部分,不容易被传统的提取方法去除。本研究旨在建立薯蓣RNA的分离方法,以获得高质量、高数量的RNA,用于EST-SSRs和snp等分子标记的生成。因此,下面的文章讨论了成功的和可重复的RNA分离方法,弗吉尼亚科学杂志,第60卷,第4期,2009年冬季,172弗吉尼亚科学杂志,山药cDNA文库构建的程序和提高RNA产量的方法材料和方法组织收集:为了标准化RNA分离方案,山药(来源:当地杂货店)在温室盆栽中生长。新鲜的1g叶片组织收集在50ml BD Falcon管中,在液氮中快速冷冻。图1所示。采用1.1%甲醛琼脂糖凝胶RNA分离方案173 RNA分离,对抗dm山药基因型和bmsensitive山药基因型的rRNA样本进行涂片。本文仅报道了对标准植物RNA分离方案进行修改后成功分离RNA的过程。·萃取缓冲液(100 ml原液):8M盐酸胍76.424g + 20mM MES 425 mg + 20mMEDTA 740mg + DEPC水35ml。用10M NaOH调节ph,放入高压灭菌器,4℃保存。使用前加入1.38μl <s:1>巯基乙醇(50mM)。·苯酚:氯仿:异丙醇(24:23:1)用液氮研磨1g组织,用2ml萃取缓冲液+ 2ml Ph:Chl:IAA匀浆。{样品均质使用动力操作的微型研磨机(钢研磨机部分在液氮中预冷),该研磨机完全适合于猎鹰管。为了提高目标RNA的质量,有必要在整个提取过程中保持冷冻状态。}。2. 样品在10,000rpm(0-2°C)下离心10分钟。3.在上清液中加入Ph:Chl:IAA(1:1体积),在-20中沉淀RNA过夜。4. 第二天,样品在10,000rpm(0-2°C)下离心20分钟,将颗粒和溶解在去离子水中(体积根据所需浓度)。5. RNA保存在-80℃。采用BIO-RAD Smartspec +分光光度计和甲醛琼脂糖凝胶电泳(Sambrook et al, 1989)确认RNA的质量。从尼日利亚Ibadon IITA地区获得了对gloeosporioides FGS菌株抗性、对SGG菌株敏感、对FGS和SGG菌株敏感的D. alata L基因型Tda 95/00328冻干叶片。叶片在液氮中研磨,并使用标准化方案分离总RNA。 6 6.438 2.9
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引用次数: 1
Dinoflagellate Cysts Within Sediment Collections From the Southern Chesapeake Bay, and Tidal Regions of the James, York, and Rappahannock Rivers, Virginia 切萨皮克湾南部沉积物中的鞭毛藻囊肿,以及弗吉尼亚州詹姆斯、约克和拉帕汉诺克河的潮汐区
Pub Date : 2008-12-31 DOI: 10.25778/2JQN-DB31
David W. Seaborn, H. Marshall
The upper 2 cm of sediment core samples from 70 stations in the tidal waters of three Virginia rivers and at 23 stations in the lower Chesapeake Bay were sampled for dinoflagellate cysts. The river sediment cysts were dominated by three common bloom producing species (Heterocapsa triquetra, Scrippsiella trochoidea, and Cochlodinium polykrikoides ), whereas these were in low concentration in the Chesapeake Bay sediments which contained mainly dinoflagellate cysts of neritic and oceanic taxa. The mean sediment concentrations from stations in the James, York, and Rappahannock rivers were respectively 1174.8, 536.2, and 323.6 cysts g1. The mean cyst concentration in the Chesapeake Bay sediment was 714. 8 t 1. Cysts of 2 potentially harmful species were recorded from the sediment, with the river sediments identified as seed beds and a source for re-occurring algal blooms in
从弗吉尼亚州三条河流潮汐水域的70个站点和切萨皮克湾下游的23个站点采集沉积物岩心上部2厘米的样本进行鞭毛藻囊肿取样。在切萨皮克湾沉积物中,主要以浅海和海洋分类群的鞭毛藻包囊为主,而以三角异花藻(Heterocapsa triquetra)、trochoidea Scrippsiella trochoidea和多核样cochlordinium polykrikoides) 3种常见产华菌为主。詹姆斯河、约克河和拉帕汉诺克河站点的平均沉积物浓度分别为1174.8、536.2和323.6个囊1。切萨皮克湾沉积物中平均囊泡浓度为714。8 . 1。从沉积物中记录了2种潜在有害物种的囊肿,河流沉积物被确定为种子床和再次发生藻华的来源
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引用次数: 15
Topographic Factors Affecting the Tree Species Composition of Forests in the Upper Piedmont of Virginia 影响弗吉尼亚上山前森林树种组成的地形因素
Pub Date : 2008-01-01 DOI: 10.25778/1SM7-XG66
Rachael C. Brown, T. Fredericksen
There are many factors that influence forest species composition and many are linked to topographical features. This study, conducted on the Ferrum College campus in the Upper Piedmont Physiographic Province of Virginia revealed three major forest types associated with topographic factors using cluster analysis and detrended correspondence analysis . The first type of forest occurred mostly on northeastern slopes on toe slope topographic positions and was mainly composed of tulip tree (Liriodendron tulipifera) and red maple (Acer rub rum). The second type of forest was found on shoulder and side slope positions and was composed mostly of high densities of sourwood ( Oxydendrum arboreum ), red maple and chestnut oak (Quercus prinus) species. The final forest type was located mostly on ridgetops and shoulder slope positions with a southwestern aspect and was composed mostly of white pine (Pinus strobus), sourwood, chestnut oak and scarlet oak (Quercus coccinea). In general, tree density increased with ascending slope position while DBH decreased. Species richness did not differ significantly by topographic position or aspect. INTRODUCTION There are many variables that influence forest species composition including soil moisture and nutrients, air temperature, light and disturbance regime. These variables are often strongly linked to topographic features such as aspect, slope position, inclination and elevation (Desta et al. 2004). Edaphic and topographic factors exert important influences along the upper Piedmont and Blue Ridge physiographic provinces of Virginia (Stephenson 1982, Harrison et al. 1989, Farrell and Ware 1991, Copenheaver et al. 2006). These forests, however, also have a long and complex disturbance history that has affected forest species composition. The forests in this region of Virginia were once dominated by American chestnut (Castanea dentata) until the invasion of the chestnut blight fungus (Endothia parasitica) in the 1920s (Johnson and Ware 1982). Following this event, highest rankings of density and basal area have been shared by a number of tree species, 1 corresponding author; tfredericksen@ferrum.edu 4 VIRGINIA JOURNAL OF SCIENCE predominately oaks (Quercus) and hickories (Carya) (Johnson and Ware 1982). A wide range of other natural and anthropogenic factors including recent ice storms (Stueve et al. 2007) and gypsy moth defoliation (Whitmire and Tobin 2006) also influence the species composition of Appalachian and Piedmont forests in Virginia. In addition, selective logging, deer browsing and the spread of invasive plant species, particularly ailanthus (Ailanthus altissima), continue to impact the structure and composition of these forests (Carter and Fredericksen 2007). This study characterized the species composition of the forests on the property of Ferrum College located on the Upper Piedmont Physiographic Province close to the Blue Ridge Escarpment in Franklin County, Virginia. Data were collected on topographic p
根据聚类分析(图1),图1、11、5、3和
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引用次数: 5
New Records, Biogeography, and Habitat Protection Needs of Four Species of Potamon (Decapoda: Brachyura) in Greece 希腊四种马铃薯的新记录、生物地理及生境保护需求
Pub Date : 2008-01-01 DOI: 10.25778/2GPZ-WQ21
E. Maurakis, David V. Grimes
Objectives are to determine the occurrence of species of Potamon in eastern Crete and the Aegean Islands (Chios, Naxos, Paros, Mykonos, Tinos and Andros); generate phylogenetic relationships among species to propose a biogeographic hypothesis relative to current distributions of the four species of the freshwater crab genus, Potamon, in Greece; and comment on the need to protect habitat suitable for the survival of species of Potamon in the country. Our collections, made in areas not previously sampled by researchers, indicate the presence of Potamon fluviatile on Tinos, N axos, and Andros, and Potamon potamios from central to eastern Crete; and verified the presence of Potamon ibericum on Chios. Cladistic analyses resulted in a single parsimonious tree (CI=85, RI=75). Potamon in the Balkan peninsula and islands in the Mediterranean region is a monophyletic group composed of two main clades: Clade 1 (P.fluviatile andPotamon algeriense) and Clade 2 (P. ibericum and its sister group composed of Potamon rhodium and Potamon potamios). Vicariant events (e.g. marine transgression and regression, orogeny, volcanism) are hypothesized as major factors that have shaped current distributions of species of Potamon in the Balkan Peninsula, Asia Minor, and the islands of the North Aegean Sea, Eastern Sporades, the Cyclades, and Crete. We recommend an increase in environmental education and communication among older and younger generations, agriculturalists, politicians, policy writers, land developers and economists to create an understanding for the need to protect land and aquatic environments that harbor unique species and the potential benefits for economic activities such as ecotourism. We also recommend the creation of an action plan to develop ecotourism around conservation areas ( e.g. from the source of existing springs downstream for about 200 m before the installation of water withdrawal equipment for irrigation and potable supplies) to generate revenue for funding protection initiatives and to promote green economic development that is ecologically and socio-culturally sustainable.
目标是确定在克里特岛东部和爱琴海群岛(希俄斯岛、纳克索斯岛、帕罗斯岛、米科诺斯岛、蒂诺斯岛和安德罗斯岛)出现的马铃薯品种;生成物种间的系统发育关系,提出一个关于希腊淡水蟹属(Potamon)四种目前分布的生物地理假说;并评论需要保护该国适合马铃薯物种生存的栖息地。我们在研究人员以前没有取样的地区收集的样品表明,在蒂诺斯岛、纳克索斯岛和安德洛斯岛以及克里特岛中部到东部地区存在流质钾;并证实了希俄斯岛上有伊比利亚马铃薯。枝源分析结果为单一简约树(CI=85, RI=75)。巴尔干半岛和地中海地区岛屿上的马铃薯是一个单系类群,由两个主要进化支组成:进化支1 (P.fluviatile和阿尔及利亚马铃薯)和进化支2 (P. ibericum及其姐妹类群,由铑马铃薯和马铃薯组成)。替代事件(如海侵和海退、造山运动、火山活动)被假设为形成了巴尔干半岛、小亚细亚、北爱琴海、东斯波拉迪斯、基克拉迪群岛和克里特岛的波达蒙物种当前分布的主要因素。我们建议在老一辈和年轻一代、农学家、政治家、政策制定者、土地开发商和经济学家之间增加环境教育和交流,以了解保护拥有独特物种的土地和水生环境的必要性,以及生态旅游等经济活动的潜在利益。我们还建议制定一项行动计划,在保护区周围发展生态旅游(例如,在安装用于灌溉和饮用水的取水设备之前,从现有泉源向下游约200米),为保护倡议创造收入,并促进生态和社会文化可持续的绿色经济发展。
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引用次数: 0
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Virginia journal of science
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