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Effects of grass and shrub cover on the critical unit stream power in overland flow

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International Journal of Sediment Research 2011年第3期26卷 385-392页

作者： M.J.M.Rmkens usda-ars National Sedimentation Laboratory OxfordMississippiUSA.

Improved knowledge of the effects of grass and shrub cover in overland flow can provide valuable information for soil and water conservation programs.Laboratory simulated rainfall studies were conducted to determine effects of grass and shrub on runoff and soil loss and to ascertain the relationship between the rate of soil loss and the unit stream power of runoff for a 20°slope subjected to rainfall intensities of 45,87,and 127 mm/h.The results indicated that the average runoff rates ranged from 4.2 to 73.1 mm/h for grass plots and from 9.3 to 58.2 mm/h for shrub plots.Runoff rates from shrub plots were less than those from grass plots for all but the 45 mm/h rainfall intensity regime. Average soil loss rates varied from 5.7 to 120.3 g/min.m~2 for grass plots and from 5.6 to 84.4 g/min.m~2 for shrub plots.Soil loss rates from shrub plots were generally lower than those from grass plots.Runoff and soil loss were strongly influenced by soil surface conditions due to the formation of erosion pits and rills.The rate of soil loss increased linearly with the unit stream power of runoff on both grass and shrub plots.Critical unit stream power values were 0.0127 m/s for grass plots and 0.0169 m/s for shrub plots.Shrub plots showed a greater stability to resist soil detachment and transport by surface flow than grass plots.

关键词： Soil erosion Soil loss Unit stream power

Antifungal Activity of Poncirus trifoliata Roots against Colletotrichum Species

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Agricultural Sciences 2023年第3期14卷 346-355页

作者： Kumudini M. Meepagala Tamang Prabin usda-ars Natural Products Utilization Research Unit University MS USA

Fruits and vegetables are an essential part of a healthy diet, providing humans with vitamins, phytonutrients, and minerals. They are significantly vulnerable, however, to post-harvest diseases caused by numerous fungal and bacterial pathogens. These pathogens can cause significant quantitative and qualitative losses from harvest to consumption during the handling and storage processes. Chemical fungicides are commonly used but are likely to leave residues on the produce, rendering short shelf-life produce, such as berries, unsuitable for human consumption. Identifying eco-friendly methods to control post-harvest disease is, therefore, of utmost importance. The presence of antifungal constituents in the roots of Poncirus trifoliata extracts was detected by thin layer chromatography-based bioautography. The active constituents were isolated and identified by bioautography assay-guided fractionation using flash chromatography followed by spectroscopic techniques. In this study, xanthoxyletin, demethylsuberosin, dentatin, nordentatin, ponfolin, and clausarin were isolated from the root extracts. The antifungal activity of these compounds was moderate to weak compared to the commercial fungicide captan. This study reports the isolation and identification of natural compounds from Poncirus trifoliata that exhibited antifungal activity against Colletotrichum fragariae and Botrytis cinerea, two major post-harvest pathogens.

关键词： Poncirus trifoliata Bioautography Colletotrichum fragariae Fungicide

A behavior and physiology-based decision support tool to predict thermal comfort and stress in non-pregnant,mid-gestation,and late-gestation sows

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Journal of Animal Science and Biotechnology 2023年第2期14卷 814-826页

作者： Betty R.McConn Allan P.Schinckel Lindsey Robbins Brianna N.Gaskill Angela R.Green‑Miller Donald C.Lay Jr Jay S.Johnson Oak Ridge Institute for Science and Education Oak RidgeTN 37830USA Department of Animal Sciences Purdue UniversityWest LafayetteIN 47907USA Department of Agricultural and Biological Engineering University of IllinoisUrbanaIL 61801USA usda-ars Livestock Behavior Research Unit West LafayetteIN 47907USA.

Background:Although thermal indices have been proposed for swine,none to our knowledge differentiate by reproductive stage or predict thermal comfort using behavioral and physiological data.The study objective was to develop a behavior and physiology-based decision support tool to predict thermal comfort and stress in multiparous(3.28±0.81)non-pregnant(n=11),mid-gestation(n=13),and late-gestation(n=12)sows.Results:Regression analyses were performed using PROC MIXED in SAS 9.4 to determine the optimal environmental indicator[dry bulb temperature(TDB)and dew point]of heat stress(HS)in non-pregnant,mid-gestation,and lategestation sows with respiration rate(RR)and body temperature(TB)successively used as the dependent variable in a cubic function.A linear relationship was observed for skin temperature(T_(S))indicating that TDB rather than the sow HS response impacted T_(S)and so T_(S)was excluded from further analyses.Reproductive stage was significant for all analyses(P<0.05).Heat stress thresholds for each reproductive stage were calculated using the inflections points of RR for mild HS and TB for moderate and severe HS.Mild HS inflection points differed for non-pregnant,mid-gestation,and late gestation sows and occurred at 25.5,25.1,and 24.0℃,respectively.Moderate HS inflection points differed for non-pregnant,mid-gestation,and late gestation sows and occurred at 28.1,27.8,and 25.5℃,respectively.Severe HS inflection points were similar for non-pregnant and mid-gestation sows(32.9℃)but differed for late-gestation sows(30.8℃).These data were integrated with previously collected behavioral thermal preference data to estimate the TDB that non-pregnant,mid-gestation,and late-gestation sows found to be cool(TDB

关键词： Decision support Gestation Heat stress Management Sows Thermal index

Identification of a novel pathway involving a GATA transcription factor in yeast and possibly in plant Zn uptake and homeostasis

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Journal of Integrative Plant Biology 2014年第3期56卷 271-280页

作者： Matthew J.Milner Nicole S.Pence Jiping Liu Leon V.Kochian Robert W.Holley Center for Agriculture and Health USDA‐ARS Cornell University Department of Plant Biology Cornell University

To gain a better understanding of the regulation of Zn homeostasis in plants and the degree of conservation of Zn homeostasis between plants and yeast, a cDNA library from the Zn/Cd hyperaccumulating plant species, Noccaea caerulescens, was screened for its ability to restore growth under Zn limiting conditions in the yeast mutant zaplA. ZAP1 is a transcription factor that activates the Zn dependent transcription of yeast genes involved in Zn uptake, including ZRT1, the yeast high affinity Zn transporter. From this screen two members of the E2F family of transcription factors were found to activate ZRT1 expression in a Zn independent manner. The activation of ZRTI by the plant E2F proteins involves E2F- mediated activation of a yeast GATA transcription factor which in turn activates ZRT1 expression. A ZRT1 promoter region necessary for activation by E2F and GATA proteins is upstream of two zinc responsive elements previously shown to bind ZAP1 in ZRT1. This activation may not involve direct binding of E2F to the ZRT1 promoter. The expression of E2F genes in yeast does not replace function of ZAP1; instead it appears to activate a novel GATA regulatory pathway involved in Zn uptake and homeostasis that is not Zn responsive.

关键词： E2F transcription factor GATA transcription factor ZRT1 Znhomeostasis

Application of Cydia pomonella expressed sequence tags： Identification and expression of three general odorant binding proteins in codling moth

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Insect Science 2013年第5期20卷 559-574页

作者： Stephen F. Garczynski Brad S. Coates Thomas R. Unruh Scott Schaeffer Derick Jiwan Tyson Koepke Amit Dhingra usda-ars Yakima Agricultural Research Laboratory Wapato WA 98951 usda-ars Corn Insect and Crop Genetics Research Unit Genetics Laboratory Iowa State University Ames IA 50011 Department of Horticulture and Landscape Architecture Washington State University Pullman WA 99164 USA

The codling moth, Cydia pomonella, is one of the most important pests of pome fruits in the world, yet the molecular genetics and the physiology of this insect remain poorly understood. A combined assembly of 8？341 expressed sequence tags was generated from Roche 454 GS-FLX sequencing of eight tissue-specific cDNA libraries. Putative chemosensory proteins （12） and odorant binding proteins （OBPs）（18） were annotated, which included three putative general OBP （GOBP）, one more than typically reported for other Lepidoptera. To further characterize CpomGOBPs, we cloned cDNA copies of their transcripts and determined their expression patterns in various tissues. Cloning and sequencing of the 698？nt transcript for CpomGOBP1 resulted in the prediction of a 163 amino acid coding region, and subsequent RT-PCR indicated that the transcripts were mainly expressed in antennae and mouthparts. The 1？289 nt （160 amino acid） CpomGOBP2 and the novel 702 nt （169 amino acid） CpomGOBP3 transcripts are mainly expressed in antennae, mouthparts, and female abdomen tips. These results indicate that next generation sequencing is useful for the identification of novel transcripts of interest, and that codling moth expresses a transcript encoding for a new member of the GOBP subfamily.

关键词： codling moth EST odorant binding proteins

Survival of boll weevil （Coleoptera： Curculionidae） adults after feeding on pollens from various sources

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Insect Science 2007年第6期14卷 503-510页

作者： SHOIL M. GREENBERG GRETCHEN D. JONES FRANK EISCHEN RANDY J. COLEMAN JOHN J. ADAMCZYK, JR. TONG-XIAN LIU MAMOUDOU SETAMOU usda-ars KSARC-BIRU Weslaco usda-ars APMRU College Station usda-ars KSARC-Honey Bee Research Unit Department of Entomology Texas AgriLife Research Texas A&M University System Texas A&M University Kingsville Citrus Center Weslaco Texas USA

The survival of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, adults on non-cotton hosts in the Lower Rio Grande Valley （LRGV） of Texas was examined from 2001 to 2006. The success of the Boll Weevil Eradication Program, which was reintroduced into the LRGV in 2005, depends on controlling overwintering boll weevil populations. Laboratory studies were conducted using boll weevil adults that were captured in pheromone traps from September through March. The number of adults captured per trap declined significantly in the field from fall to the beginning of spring （3.5-7.0-fold）. The proportion of trapped males and females did not differ significantly. The mean weight of boll weevil adults captured in September was 13.3 mg, while those of captured adults from November to February were significantly lower and ranged from 6.7 to 7.8 mg. Our results show that boll weevil adults can feed on different plant pollens. The highest longevity occurred when adults were fed almond pollen or mixed pollens （72.6 days and 69.2 days, respectively） and the lowest when they fed on citrus pollen or a non-food source （9.7 days or 7.4 days, respectively）. The highest adult survival occurred on almond and mixed pollens [88.0%-97. 6% after 1st feeding period （10 days）, 78.0%-90.8% after 3rd feeding period （10 days）, 55. 0%-83.6% after 5th feeding period （10 days）, and 15.2%-32.4% after lOth feeding period （10 days）]. The lowest adult survival occurred on citrus pollen [52.0%-56.0% after 1st feeding period （10 days）, 13.3% after 3rd and 5th feeding periods （10 days）, and 0 after 6th feeding period （10 days）]. Pollen feeding is not a behavior restricted to adult boll weevils of a specific sex or physiological state. Understanding how boll weevil adults survive in the absence of cotton is important to ensure ultimate success of eradicating this pest in the subtropics.

关键词： boll weevil Anthonomus grandis grandis Curculionidae subtropics pollen

Circadian rhythms of feeding, oviposition, and emergence of the boll weevil （Coleoptera： Curculionidae）

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Insect Science 2006年第6期13卷 461-467页

作者： SHOIL M. GREENBERG J. SCOTT ARMSTRONG MAMOUDOUSETAMOU THOMAS W. SAPPINGTON RANDY J. COLEMAN TONG-XIAN LIU usda-ars-SARC-BIRU Texas A&M University Agricultural Experiment Station Weslaco Texas usda-ars-CICGRU Ames Iow USA

Circadian rhythm of feeding, oviposition, and emergence of boll weevil adults were determined at five different photophases （24, 14, 12, 10, and 0 hours） and a constant 27℃ temperature, 65% RH in the laboratory. Squares from Petri dishes, where they were exposed to boll weevil females, were removed and examined for feeding and oviposition punctures every 4 hours during daylight （0700-1900 h） and every 12 h at night （1900-0700 h） over eight consecutive days. Cohorts of randomly selected egg-punctured squares were sampled from ovipositing females at 0700, 1100, 1500, and 1900 during 24 hours and under different photophase treatments, and maintained in Petri dishes at 27 ＋ I℃, 65% RH. Dishes were observed twice daily （1900 and 0700 h） for adults emerging at day or night. Circadian rhythm of oviposition was not affected by the length of the photophase. The boll weevil has round-the-clock circadian rhythm of oviposition, with a daytime preference. We observed that 82.4%-86.0% of the boll weevil eggs were deposited between 0700 and 1900 h, and 14.0%-17.6% between 1900 and 0700 h during a 24-h period. Feeding of boll weevil females in photoperiods 24：0 h （complete light） and 0：24 h （complete darkness） did not significantly change between 0700-1900 h versus 1900-0700 h, while the d .ally cycle of light and darkness in other photoperiods significantly increased the feeding punctures from 0700-1900 compared with 1900-0700 h. The circadian rhythm of emergence depended significantly on the time of oviposition and the length of the photophase. Investigation of boll weevil circadian rhythm provides a better understanding of boll weevil ecology and reveals potential weak links for improving control technologies targeting their reproductive strategies.

关键词： Anthonomus grandis emergence circadian rhythm oviposition photophase

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Root architecture

Journal of Integrative Plant Biology 2016年第3期58卷 190-192页

作者： leon v.kochian robert w.holley center for agriculture and health usda-arscornell universityIthacaNY 14853USA

Numerous research publications over the past 20 years have made it quite clear that a better understanding of the molecular and genetic basis for variation in root system architecture（RSA）will greatly aid the develo... 详细信息

关键词： Root publications nutrient entitled limiting maize breeding pioneering roots drought

Rapid Identification of Rice Samples Using an Electronic Nose

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Journal of Bionic Engineering 2009年第3期6卷 290-297页

作者： John Westbrook W.C.Hoffmann R.E.Lacey usda-ars College Station Department of Biological and Agricultural Engineering Texas A&M UniversityCollege Station

Four rice samples of long grain type were tested using an electronic nose (Cyranose-320).Samples of 5 g of each variety of rice were placed individually in vials and were analyzed with the electronic nose unit consisting of 32 polymer sensors.The Cyranose-320 was able to differentiate between varieties of rice.The chemical composition of the rice odors for differentiating rice samples needs to be investigated.The optimum parameter settings should be considered during the Cyranose-320 training process especially for multiple samples,which are helpful for obtaining an accurate training model to improve identification capability.Further,it is necessary to investigate the E-nose sensor selection for obtaining better classification accuracy.A re- duced number of sensors could potentially shorten the data processing time,and could be used to establish an application pro- cedure and reduce the cost for a specific electronic nose.Further research is needed for developing analytical procedures that adapt the Cyranose-320 as a tool for testing rice quality.

关键词： rice grain identification electronic nose data analysis pattern recognition