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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Bioaccumulation of Triclocarban, Triclosan, and Methyl-triclosan in a North Texas Wastewater Treatment Plant Receiving Stream and Effects of Triclosan on Algal Lipid Synthesis.

Coogan, Melinda Ann 08 1900 (has links)
Triclosan (TCS) and triclocarban (TCC), widely used antimicrobial agents found in numerous consumer products, are incompletely removed by wastewater treatment plant (WWTP) processing. Methyl-triclosan (M-TCS) is a more lipophilic metabolite of its parent compound, TCS. The focus of this study was to quantify bioaccumulation factors (BAFs) for TCS, M-TCS, and TCC in Pecan creek, the receiving stream for the City of Denton, Texas WWTP by using field samples mostly composed of the alga Cladophora sp. and the caged snail Helisoma trivolvis as test species. Additionally, TCS effects on E. coli and Arabidopsis have been shown to reduce fatty acid biosynthesis and total lipid content by inhibiting the trans-2 enoyl- ACP reductase. The lipid synthesis pathway effects of TCS on field samples of Cladophora spp. were also investigated in this study by using [2-14C]acetate radiolabeling procedures. Preliminary results indicate high TCS concentrations are toxic to lipid biosynthesis and reduce [2-14C]acetate incorporation into total lipids. These results have led to the concern that chronic exposure of algae in receiving streams to environmentally relevant TCS concentrations might affect their nutrient value. If consumer growth is limited, trophic cascade strength may be affected and serve to limit population growth and reproduction of herbivores in these riparian systems.
62

Pecan Production Guidelines for Small Orchards and Home Yards

Call, Rob, Gibson, Rick, Kilby, Mike 05 1900 (has links)
12 pp.
63

Salinity Management and Soil Amendments for Southwestern Pecan Orchards

Walworth, James, Thompson, Thomas L. 07 1900 (has links)
4 pp. / Managing salts in Southwestern pecan orchards can be a major challenge for growers, due to limited soil permeability and/or low-quality irrigation water.
64

Salinity Management and Soil Amendments for Southwestern Pecan Orchards

Walworth, J. L. 10 1900 (has links)
Revised; Originally Published: 2006 / 4 pp.
65

Bats, insects and pecans: habitat use and ecosystem services of insectivorous bats in a pecan agroecosystem in central Texas

Braun de Torrez, Elizabeth Claire 22 January 2016 (has links)
Comprehensive wildlife conservation strategies must include consideration of the agricultural matrix and its integration into the greater landscape. Bats are postulated to provide critical pest suppression services, but the effects of agricultural intensification on insectivorous bats are not clear. Few studies have thoroughly investigated the ecosystem services provided by bats due, in part, to limited understanding of species-specific habitat use in agricultural landscapes, difficulties in prey identification, and the challenge of quantifying the impact of bats on pest populations and crops. My dissertation integrates these components to describe ecological relationships between the insects and bats associated with a pecan agroecosystem in central Texas. Specifically, I focus on the predator-prey relationship between bats and the pecan nut casebearer moth (PNC), a devastating pest of pecans. I begin with a literature review of the ecosystem services of insectivorous bats and the data necessary to thoroughly evaluate these services. I then assess the potential factors influencing species composition and spatio-temporal distributions of bats within the pecan agroecosystem. My results demonstrate higher activity and diversity of bats within the pecan agroecosystem than in the surrounding landscape likely due to roosting opportunities, but species-specific and seasonal differences exist in the effects of management intensity. Next, I investigate direct interactions between bats and PNC by measuring prey consumption patterns. I found that five species of bats prey upon PNC moths during all three critical population peaks prior to insecticide application, but there is variability in consumption among species. Finally, I assess indirect interactions between bats and pecans, by evaluating the effect of bat predation risk on pecan damage by PNC larvae. A negative relationship between foraging activity by bats and both PNC moths and PNC larval damage to pecans provides evidence that bat predation has quantitative downstream effects. My results highlight the conservation value of the agricultural matrix for bats and the complexities of accurately documenting ecosystem services provided by free-ranging mobile organisms.
66

Efeito protetor e/ou restaurador do chá da casca de noz-pecã (Carya illinoensis) sobre a espermatogênese de ratos wistar submetidos ao choque térmico testicular

LIMA, Luiz André Rodrigues de 10 February 2011 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-05-18T14:02:23Z No. of bitstreams: 1 Luiz Andre Rodrigues de Lima.pdf: 2120469 bytes, checksum: 547b856a4a41c79b0e6825587dbb6569 (MD5) / Made available in DSpace on 2016-05-18T14:02:23Z (GMT). No. of bitstreams: 1 Luiz Andre Rodrigues de Lima.pdf: 2120469 bytes, checksum: 547b856a4a41c79b0e6825587dbb6569 (MD5) Previous issue date: 2011-02-10 / The directly heat applied on the testis has given new information about the mechanisms triggers of spermatogenesis damages. Pecan nut shell [Carya illinoensis (Wangenh) K. Koch], is a vegetal by-product with low cost and elevated antioxidant potential and therefore can be considered a promissory substance, because it is rich in polifenols, condensed tannins, flavonoids substances and proanthocyanidis. The aim of this study was to verify whether the pecan nut tea has been protective effects against deleterious actions, produced by heat in the testicular parenchyma and its capacity to accelerate the spermatogenesis recovery process. Forty-five male Wistar rats (Rattus norvegicus, var. albinus) were used and divided in three groups. The testicular heat shock (HS) were been applied in all animals. The first one group G1 hadn’t received pecan nut tea on its diet; the second G2, only received the cited tea before (HS) and the third group G3 received the pecan nut tea before and after HS. The animals were evaluated on 15, 30 and 60 days after heat shock according to histopathological and histometrical testis alterations as well plasmatic testosterone. The occurrence of oxidative stress (OS) was observed through the determination of lipid peroxidation (LP), measured by the thiobarbituric acid reactive substances (TBARS). Carbonil group, reduced glutathione (GSH), vitamin C levels, catalase activity and protein content in testis were evaluated. In this work was observed a recover of testis weight recover in animals belong to G1 and G2 groups at 30 and 60 days. The epididymal weight of G3, at 15 and 30 days showed an improvement when related with G1 and G2 groups. The prostate and seminal gland weight in G2 and G3 had an improvement in weight when compared with G1 group, at 30 day. The pecan nut tea prevented a total Leydig cell volume reduction at 30 day post thermal injury. The total volume of seminiferous tubules was quickly recovered on G2 and G3 groups at 30 days than G1 group. The seminiferous tubule volume followed the same pattern of seminiferous tubule. Regarding to tunica propria and blood vessel, animals treated with pecan nut tea had a reduction of this parameter at 60 days. The total length of seminiferous tubules was maintained in animals that took continuously pecan nut tea. The plasmatic levels of testosterone were maintained at 15 days in G2 and G3 groups, and after that was noted a lower testosterone levels tendency at 30 and 60 days. By the other side, testosterone levels in animals of G1 group become higher gradually at 15 until 60 days. According to histopathological findings was noted that prior administration of pecan nut tea, before heat shock had better effect on recovery of spermatogenic process at 30 and 60 days. The treatment with pecan nut tea was able to prevent the TBARS increase and GSH depletion in testis. There weren’t significative changes on the plasmatic vitamin C levels, carbonil groups, catalase activity and protein content in the testis of animals. / O calor aplicado diretamente sobre o testículo tem fornecido novas informações sobre os mecanismos desencadeadores dos danos à espermatogênese. A casca da noz pecã [Carya illinoensis (Wangenh) K. Koch] é um sub-produto de origem vegetal de baixo custo e com elevado potencial antioxidante, constituída por polifenóis, taninos condensados, substâncias flavonóides e proantocianinas. O objetivo deste trabalho foi verificar se o chá de noz-pecã apresenta efeito preventivo e/ou restaurador contra as ações deletérias produzidas pelo calor no parênquima testicular, assim como avaliar a capacidade deste em acelerar a recuperação do processo espermatogênico. Foram utilizados 45 ratos Wistar machos (Rattus norvegicus, var. albinus) divididos em três grupos: G1- choque térmico, G2 - chá de noz-pecã pré-choque térmico e G3 - chá de noz-pecã pré e pós-choque térmico. Os animais foram avaliados aos 15, 30 e 60 dias pós-choque térmico quanto às alterações histopatológicas e histomorfométricas dos testículos, assim como, determinou-se níveis plasmáticos de testosterona. Parâmetros de estresse oxidativo (EO) foram avaliados no homogenato de testículo através da peroxidação lipídica (LPO), medida por meio da formação de espécies reativas ao ácido tiobarbitúrico (TBARS). Grupo carbonil, glutationa reduzida (GSH), níveis de vitamina C (VIT C), atividade da catalase e conteúdo protéico também foram determinados. Neste trabalho foi constatada tendência de recuperação do peso testicular dos animais dos grupos G2 e G3 aos 30 e 60 dias. O peso epididimário dos animais do grupo G3, aos 15 e 30 dias apresentou uma melhora significativa em relação aos grupos G1 e G2. Os pesos da próstata e vesícula seminal em G2 e G3 aumentaram em relação ao grupo G1, aos 30 dias. A administração do chá da casca de noz-pecã preveniu a redução do volume total de células de Leydig no período de 30 dias pós-injúria. O volume total de túbulos seminíferos foi recuperado mais rapidamente nos grupos G2 e G3 aos 30 dias do que o grupo G1. O volume de epitélio seminífero seguiu o mesmo padrão do túbulo seminífero, porém aos 60 dias. No tocante à túnica própria e vasos sanguíneos, os animais tratados com chá tiveram redução volumétrica neste parâmetro aos 60 dias. O comprimento total dos túbulos seminíferos foi preservado nos animais que fizeram uso contínuo do chá de noz-pecã. Os níveis plasmáticos de testosterona foram mantidos aos 15 dias nos grupos G2 e G3, e posteriormente notou-se tendência de diminuição destes níveis aos 30 e 60 dias. Por outro lado, os níveis plasmáticos de testosterona nos animais do grupo G1 aumentaram gradativamente dos 15 aos 60 dias. De acordo com os achados histopatológicos, constatou-se que a administração prévia de chá de noz-pecã ao insulto térmico proporcionou uma melhor qualidade na recuperação do processo espermatogênico aos 30 e 60 dias. O tratamento com chá de noz-pecã foi capaz de prevenir o aumento do TBARS e diminuição do GHS nos testículos. Não houve diferença significativa nos níveis de VIT C, grupos carbonil, atividade da catalase e no conteúdo protéico dos testículos dos animais. Os resultados obtidos demonstraram que o tratamento com chá da casca de noz-pecã, tanto administrado previamente aos animais como depois da injúria térmica testicular apresentaram efeitos preventivos e restauradores da espermatogênese.
67

SEASONAL POPULATION TRENDS OF BLACKMARGINED APHID (MONELLIA CARYELLA) AND GREEN LACEWING (CHRYSOPA CARNEA) ON ALDICARB TREATED AND UNTREATED PECAN TREES IN SOUTHEASTERN ARIZONA.

Nowell, Catherine Ellen. January 1983 (has links)
No description available.
68

Just like Ole' Mammy used to Make: Reinterpreting New Orleans African-American Praline Vendors as Entrepreneurs

Nunez, Chanda 20 May 2011 (has links)
Women commonly sold goods on the streets of New Orleans throughout the city‘s colonial and antebellum history. Forming a significant presence among the city‘s market places, they sold various food items which included coffee, calas, and pralines. Perhaps the most popular of the African-American street vendors was the praline women. They attracted the attention of visitors as well as residents. Despite the popularity of these treats, the highly visible and enterprising praline vendors were simultaneously celebrated and caricatured by white observers who depicted them as mammy figures not only in store advertisements and logos, but also in everyday annotations.
69

AÇÃO PROTETORA DA Carya illinoensis SOBRE A TOXICIDADE INDUZIDA POR CICLOFOSFAMIDA EM RATOS / ACTION OF Carya illinoensis ON THE CYCLOPHOSPHAMIDE INDUCED TOXICITY IN RATS

Benvegnú, Dalila Moter 29 January 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cyclophosphamide (CP) is an alkylating agent widely used in anticancer and immunosuppression therapy. Like other chemotherapies, this drug can induce damage in healthy tissues, generating multiple organ toxicity. The study of natural substances able to prevent or reduce the toxicity induced by the chemotherapy is very important. Pecan nut shell (Carya illinoensis) is a vegetal by-product with low cost and elevated antioxidant potential and therefore can be considered a promissory substance. The aim of this study was to verify whether the cited antioxidant protects against multiple tissue damage induced by CP. Wistar rats received water or pecan shell aqueous extract (AE - 5%) ad libitum in place of drinking water up to the end of the experiment. On day 30, half of each group received a single administration of vehicle or CP 200 mg/kg-ip. After 7 days, the animals were sacrificed by exsanguination. The blood was collected to obtain plasma and erythrocytes. Vital tissues as heart, liver, kidney, testis and bladder were removed. The occurrence of oxidative stress (OS) was observed through the determination of lipid peroxidation (LP), measured by the thiobarbituric acid reactive substances (TBARS) formation and reduced glutathione (GSH) in all removed tissues, the enzyme catalase (CAT) in the heart, liver, kidney and testis, the enzyme superoxide dismutase (SOD) in the testis and the plasmatic vitamin C (VIT C) levels. Furthermore, the testicular function was evaluated by the enzyme lactate deydrogenase (LDH) and the macroscopic and histopathological analysis of the bladder was carried out. Results demonstrated that the CP treatment increased TBARS and decreased GSH levels in all studied tissues. Moreover, the activities of SOD in the testis and CAT in the heart were increased. However, in the other organs, the activity of the latter was diminished. The testicular LDH and plasmatic VIT C levels were also decreased. Finally, the bladder of the CP treated rats showed dark color and various histological alterations, such as thickening of the lines, hemorrhage, edema, leukocyte infiltration and vascular proliferation. The co-treatment with AE was able to prevent the TBARS increase and GSH depletion in all tissues, except heart and plasma, respectively. The extract also prevented changes in the testicular SOD and CAT activity in all organs, except the kidney. Besides, the extract prevented alteration in plasmatic VIT C and testicular LDH as well as various visual and histological changes in the rat bladder. These findings provided important evidences of the protective effect of pecan shell AE against the general organic toxicity induced by CP. Therefore, this natural substance may be considered to minimize adverse effects related with this chemotherapy, improving the life quality of patients who need to use this type of drug. / A ciclofosfamida (CP) é um agente alquilante muito usado na terapia anticâncer e imunossupressora. Assim como outros quimioterápicos, este fármaco pode causar danos aos tecidos saudáveis, gerando toxicidade em múltiplos órgãos. Desta forma, o estudo de substâncias naturais capazes de prevenir ou minimizar a toxicidade decorrente do tratamento quimioterápico vem ganhando sua importância. A casca da noz pecã (Carya illinoensis), é um sub-produto de origem vegetal de baixo custo e com elevado potencial antioxidante, constituindo uma substância promissora. O objetivo deste estudo foi verificar se o extrato aquoso bruto do vegetal citado apresenta efeito protetor contra os danos teciduais múltiplos induzidos pela CP. Ratos Wistar receberam água potável ou extrato aquoso bruto (EAB 5%) da casca da noz pecã, ad libitum, no lugar da água de beber até o final do experimento. No trigésimo dia, a metade de cada grupo recebeu uma administração única de veículo ou CP 200 mg/kg-ip. Após 7 dias, os animais foram sacrificados por exsanguinação, para obtenção de plasma e eritrócitos, enquanto alguns tecidos como coração, fígado, rim, testículos e bexiga foram removidos. Parâmetros de estresse oxidativo (EO) foram avaliados através da peroxidação lipídica (LPO), medida por meio da formação de espécies reativas ao ácido tiobarbitúrico (TBARS) e glutationa reduzida (GSH) em todos os tecidos avaliados, bem como a enzima catalase (CAT) no coração, fígado, rim e testículos. A enzima superóxido dismutase (SOD) testicular e os níveis plasmáticos de vitamina C (VIT C) também foram determinados. A função testicular foi determinada através dos níveis da enzima lactato desidrogenase (LDH). A bexiga foi submetida à avaliação macroscópica e histopatológica, já que é um tecido intensamente danificado pela CP. Os resultados obtidos demonstraram que o tratamento com CP aumentou os níveis de TBARS e diminuiu os níveis de GSH em todos os tecidos avaliados. A atividade da SOD testicular apresentou-se aumentada, bem como a atividade da CAT no coração. Nos demais órgãos, a atividade desta última enzima encontrou-se diminuída. Os níveis da enzima LDH testicular e os níveis plasmáticos de VIT C também se apresentaram reduzidos. Por último, as bexigas dos ratos tratados com CP mostraram coloração escura e diversas alterações histológicas, tais como: espessamento das camadas, hemorragia, edema, infiltração leucocitária e proliferação vascular. O co-tratamento com EAB foi capaz de prevenir o aumento do TBARS e diminuição do GSH em todos os tecidos, exceto coração e plasma, respectivamente. O extrato também preveniu modificações na atividade da SOD testicular e da CAT em todos os órgãos, exceto no rim. Além disso, o extrato também preveniu as alterações nos níveis de VIT C plasmática e LDH testicular, bem como as modificações macroscópicas e histopatológicas na bexiga dos ratos tratados com CP. Os resultados apresentados aqui evidenciam os efeitos protetores do EAB das casca da noz pecã sobre a toxicidade generalizada da CP. Deste modo, este sub-produto da indústria da noz pode ser considerado para minimizar os efeitos indesejáveis relacionados ao tratamento com CP, melhorando a qualidade de vida dos pacientes que necessitam deste quimioterápico.
70

Municipal and agricultural wastewater remediation using modified biochars

Crisler, Glenn, II 09 August 2019 (has links)
Water contaminated by heavy metals and plant nutrients pose a threat to human health and safety as well as the environment. The aim of this body of work is to develop, characterize, and understand the adsorption properties of green sorbents to mitigate these risks. Biochar, an adsorbent known to be both environmentally friendly and inexpensive was used. Advantages of biochar are its high surface area, easy modification, and native surface functionality. Biochars used in this study are of pecan shell or douglas fir origin, although biochar can be made from a host of waste organic materials. Pecan shell biochar was modified using a simple water soaking activation technique which is totally green and free of any harsh solvents, whereas the douglas fir biochar was modified to contain both aluminum and magnesium oxides via coprecipitation of Al and Mg sulfate salts and NaOH treatment. Chapter I provides an introduction of biochar production methods as well as a brief history of its utilization. Chapter II is a study of lead removal using biochars obtained from slow pyrolysis of dry and water soaked pecan shell biomass. In this study, water, a green and low cost reagent, was used to maximize the surface area of pecan shell biochar allowing it to adsorb more lead from aqueous solution. In this study, pecan shell biochar is analyzed using several methods including SEM, SEM-EDX, TEM, PZC, XRD, elemental analysis, and BET. Chapter III discusses the remediation of agricultural runoff water using slag and Al/ Mg modified biochar. This study characterizes both biochar and slag using various methods including SEM, SEM-EDX, TEM, PZC, XRD, elemental analysis, and BET. Chapter IV focuses phosphates in soils: An undergraduate exploration according to soil texture and amendment. The purpose of this study was to bring the cutting edge research regarding phosphate retention into the undergraduate laboratory setting.

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