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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.
1

Non-leaf chlorenchyma in Bienertia cycloptera and Suaeda aralocaspica (chenopodiaceae) exhibit single cell C₄ photosynthesis

Clay, Christine Nicole, January 2006 (has links) (PDF)
Thesis (M.S. in botany)--Washington State University, May 2006. / Includes bibliographical references (p. 23-24).
2

The Effects of Tamoxifen on Mammary Development in Prepubertal Heifers

Tucker, Hannah L. 28 August 2013 (has links)
Our purpose was to determine the effects on mammary gland development in prepubertal heifers given the anti-estrogen tamoxifen. Sixteen Holstein calves were randomly assigned to one of two treatment groups: tamoxifen-injected (TAM) or control (CON). Calves were subcutaneously injected daily from 28 to 120 days of age with 0.3 mg/kg tamoxifen or carrier. At 120 days calves were euthanized and udders removed. Weight of trimmed parenchymal tissue (left rear quarter) was dramatically lower in TAM calves than in CON calves (p < 0.0003; 16.1 vs. 34.8 g). Parenchymal samples from three regions of the left rear quarter (lower, middle and outer regions) were processed for immunohistochemical staining for Estrogen Receptor α and Progesterone Receptor, myoepithelial cells, and label retaining cells. Overall, the proportion of neither ER nor PR labeled cells was impacted by TAM treatment. However, imaging analysis indicated a markedly higher intensity of ER expression in CON calves. TAM caused an increase in myoepithelial cell differentiation similar to what is seen in ovariectomy. We were able to effectively use a new technique of multispectral imaging to identify label retaining cells, which led to the discovery of an increase in the percentage of label retaining cells in TAM compared to CON. While treatment with the anti-estrogen tamoxifen reduced mammary parenchymal mass similarly to OVX, the mechanism(s) involved appear to differ. This suggests that the impacts of ovariectomy are only partially explained by the absence of estrogen. / Master of Science
3

Nitrosative and oxidative stress in Nippostrongylus brasiliensis induced pulmonary inflammation

McNeil, Kathryn Suzanne January 1999 (has links)
No description available.
4

The aging process of sapwood ray parenchyma cells in four woody species

Yang, Kung Chi January 1990 (has links)
Aging of ray parenchyma cells from the young sap-wood to recently formed heartwood was studied in single stems of Pinus banksiana Lamb., Picea mariana (Mill.) B.S.P., Abies balsamea (L.) Mill, and Populus tremuloides Michx. Season, radial location of cell within sapwood, and cell location vertically within a ray at a given radius were considered as factors which might influence the aging process. A 12 mm increment core was extracted at breast height, from the north aspect of a tree of each species in May and July for moisture content determination. Another set of cores from the south aspect of the same trees was collected in May, June, July, August, October, and November or December. These cores were used to investigate the physiological and cytological properties of living sapwood ray parenchyma cells. Qualitative and quantitative observations were made of the status of ray cells both with light and transmission electron microscopy in order to draw inferences concerning the sapwood/heartwood transformation from the aging of sapwood ray parenchyma cells. The sapwood moisture content of the three conifers studied was higher than that of heartwood, whereas in Populus tremuloides it was lower than that of heartwood. The sapwood moisture content in May was consistently greater than in July. Vitality of the sapwood ray parenchyma cells expressed by a new nuclear elongation index decreased from the outer sapwood towards the heartwood. The survival rate of the cells decreased curvilinearly from the middle sapwood towards the heartwood. At a given sapwood increment, a greater percentage of dead ray parenchyma cells was found among the marginal cells than among the central cells of a ray. No statistically significant difference was found between the vitality of the marginal and central cells, nor between any two contiguous sampling periods with exceptions in Pinus banksiana and Picea mariana between two contiguous sampling periods from July to December. No typical pattern for the distribution of lipid content was found. The pattern of starch distribution displayed significant species, radial, vertical and seasonal variation and showed two general patterns across the sapwood. Pattern A described a decreasing trend from the outer sapwood towards the inner sapwood. Pattern B was characterized by a relatively low starch content both in the outer as well as the inner sapwood. The starch content in Populus tremuloides and the lipid content in Pinus banksiana and Picea mariana displayed no statistically significant difference between marginal and central ray cells. The majority of ray parenchyma cells showed a statistically significant difference between two contiguous sampling periods in starch and lipid contents. There was no inverse relationship between the starch and lipid content over the growing season studied. Young ray parenchyma cells were rich in chromatin and cytoplasm which contained numerous cell organelles. These cells were characterized by amyloplasts which possessed one or more elongated starch granules with thylakoids and osmiophilic globuli, numerous small lipid droplets and mostly rod-like mitochondria. In contrast, aged ray parenchyma cells featured an aggregated, dense nucleus and cytoplasm which contained few cell organelles. These aged cells possessed enlarged swollen starch granules, large lipid droplets or lumps with two staining densities, round shaped mitochondria with inconspicuous cristae and a rough/broken plasmalemma. Some heartwood substances originated from the lipid lumps which appeared frequently in dying ray cells. Based on microscopic observations and measurements of the loss of vitality of ray parenchyma cells, a declining survival rate, the disintegration of cell organelles and the origin of heartwood substances from lipid lumps, it can be concluded that heartwood formation is largely associated with the death of sapwood ray parenchyma cells. The death of these cells is due to the passage of time. / Forestry, Faculty of / Graduate
5

Differential gene expression in the culm of sugarcane during development, with special emphasis on the storage parenchyma cells

Rogbeer, Omeswaree 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: For the expression of transgenes in plant cells, appropriate promoter sequences have to be introduced upstream of the gene to ensure efficient transcription. While to date the maize ubiquitin (Ubi1) promoter has been the most effective transgene promoter for sugarcane, there is a high demand for tissue and stage specific promoters for localised transgene expression in the mature culm. The present study sought to characterise genes preferentially expressed in the core and peripheral tissues of the mature culm, which can further be used as research tools for specific promoter isolation. cDNA expression arrays containing 3840 clones from a late stage cDNA library representative of the core and peripheral tissues of the mature culm were prepared. The cDNA expression arrays were then differentially screened in independent hybridisation experiments with radioactively-labeled cDNA representations of core and peripheral tissues of internode 7, and peripheral tissues of internode 10. Comparison of the expression profiles of the arrayed cDNA targets in the three probes led to the identification of 60 tissue-specific, 17 stage-specific and 50 selectively expressed cDNAs within the mature sugarcane culm. ~ESTs of 33 chosen selectively expressed cDNAs with a relatively stronger pattern of expression in the core than in the peripheral tissues revealed sequence homology to a diverse collection of genes in the mature culm. These included genes associated with general cellular metabolism such as protein synthesis, protein modification and structural protein. Also identified were stress-responsive genes. The putative translational products of some of these clones had homologs that are involved in cell-wall structure in other species. These included the [acalin homolog, a lectin, hydroxyproline rich glycoprotein and structured polyprotein C. Many of the cDNAs thought to be involved in cell wall structure or stress related responses also accumulate in a developmental manner in other plants. These may indicate that specific mature culm mRNAs accumulate in response to stresses such as rapid cell expansion or as part of the late developmental program. An unexpected observation was that only one gene associated with sucrose metabolism was identified, namely sucrose synthase. These results confirmed that culm maturation was not controlled by sucrose metabolism despite its distinct physiological characteristic of storing high levels of sugars. ESTs analysis further revealed that sequence homology was not obtained for all the cDNAs exhibiting stage and tissue specific expression in the core and peripheral tissues of the mature culm. These could represent novel genes not only from sugarcane but all plants. Northern analysis demonstrated that 9 putatively identified selectively expressed genes tested so far accumulated specifically in the core and peripheral tissues of the mature culm. No expression was detected in root, leaf, leafroll and internode 3. However, their selective expression in a single internode as observed on the arrays (i.e hybridisation signal intensity being higher in the core than in the peripheral tissue) was not detected on the northern blots. These showed that cDNA expression arrays were not a highcapacity gene expression assay since they were prone to false expression analysis. The validity of results obtained through array screening should always be verified in an independent manner, preferably by the northern hybridisation analysis. Hence, the present study shows that the combination of differential screening, northern blot and DNA sequence analysis permits the rapid characterisation of differentially expressed genes in the core and peripheral tissues of the mature sugarcane culm. These can further be used as research tools for mature culm - specific promoter isolation in the sugarcane. / AFRIKAANSE OPSOMMING: Die doeltreffende uitdrukking van transgene in plantselle is afhanklik van 'n gepaste promotorvolgorde wat stroomop van die geen ingevoeg word. Die Ubi1-promotor van mielies was tot dusver die doeltreffendste transgeenpromotor in suikerriet, maar daar is 'n groot behoefte aan promotors wat weefsel- en ontwikkelingstadium-spesifieke geenuitdrukking kan beheer. Hierdie studie het op die isolering en karakterisering van gene wat selektief in die kern- of periferale stingelweefsel van suikerriet uitgedruk word, gefokus. Hierdie gene sal verder benut kan word om promotors te isoleer. eDNA uitdrukkingsreekse ("expression arrays") van 'n volwasse stingel eDNA biblioteek is voorberei. Hierdie reekse, wat 3840 klone bevat het, is in onafhanklike hibridiseringseksperimente met radioaktiefgemerkte eDNA van onderskeidelik kern- en periferale stingelweefsel van lit 7 en periferale stingelweefsel van lit 10 afgetas. 'n Vergelyking van die uitdrukkingsprofiele van die eDNA teikens in dié drie peilergroepe het tot die identifisering van 60 weefsel-spesifieke-, 17 ontwikkelingstadium-spesifiekeen 50 selektief uitgedrukte eDNAs in die volwasse suikerrietstingel gelei. Uitdrukkingsvolgordemerkers ("ESTs") van 33 geselekteerde eDNAs wat in hoër vlakke in die kern uitgedruk is, se volgordes toon homologie aan 'n wye verskeidenheid gene in die volwasse stingel. Hierdie groep sluit gene in wat met algemene sellulêre ..metabolisme soos proteïensintese, proteïenmodifisering en strukturele proteïene geassosieer is. Spanningsverwante gene is ook hier geïdentifiseer. Die transleringsprodukte van sommige klone het homoloë wat by selwandstruktuur in ander spesies betrokke is, soos die jaealin-homoloog, 'n lektien, hidroksiprolien-ryke glikoproteïen en gestruktureerde poliproteïen C. 'n Wye verskeidenheid eDNAs wat by selwandstruktuur of spanningsverwante reaksies betrokke is, akkumuleer ook in 'n ontwikkelingsafhanklike wyse in ander plante. Dit mag 'n aanduiding wees dat spesifieke mRNAs in die volwasse stingel in reaksie op spanning wat met vinnige seluitsetting gepaardgaan, versamel. Slegs een geen wat met sukrose metabolisme geassosieer is, nl. sukrosesintase, is in hierdie studie geïdentifiseer. Hierdie onverwagte waarneming het bevestig dat, ondanks suikerriet se kenmerkende vermoë om hoë konsentrasies suiker te berg, stingelveroudering nie net met sukrose metabolisme geassosieer kan word nie. Nie al die eDNA-fragmente wat geïsoleer is, het homologie aan ander gene in die internasionale databasisse getoon nie, wat moontlik kan aandui dat nuwe gene suksesvol geïsoleer is. Nege ontwikkelingstadium-spesifieke gene wat slegs in die volwasse stingelweefsels uitgedruk word, is dmv noordelike oordraganalises geïdentifiseer. Geen transkripte van hierdie gene is in die wortels, blaarrol, blare of jong stingel waargeneem nie. Die weefselspesifisiteit wat met die uitdrukkingsreekse waargeneem is, kon nie mbv noordelike orrdraganalises bevestig word nie. Dit mag 'n aanduiding wees dat die uitdrukkingsreekse vals positiewe resultate kan oplewer en dit is raadsaam om voortaan altyd die verkrygde profiele met ander, meer sensitiewe tegnieke, te bevestig. Die studie het aangetoon dat 'n kombinasie van differensiële aftasting, noordelike oordraganalise en DNA-volgordebepaling gebruik kan word om gene wat differensieel uitgedruk word in die volwasse suikerrietstingel, te identifiseer. Hierdie geenfragmente kan nou vir promotorisoleringsdoeleindes aangewend word.
6

Functional and ecological significance of leaf vein / 葉脈の機能と生態学的意義

Kawai, Kiyosada 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21824号 / 農博第2337号 / 新制||農||1067(附属図書館) / 学位論文||H31||N5196(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 大澤 晃, 教授 北山 兼弘, 教授 北島 薫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
7

Theoretical and numerical modelling of biologically inspired composite materials

Ongaro, Federica January 2017 (has links)
The cellular nature of many biological materials, providing them with low density, high strength and high toughness, have fascinated many researchers in the field of botany and structural biology since at least one century. Bamboo, sponges, trabecular bone, tooth and honeybee combs are only few examples of natural materials with cellular architecture. It has been widely recognised that the geometric and mechanical characteristics of the microscopic building blocks play a fundamental role on the behavior observed at the macroscale. Up to date, many efforts have been devoted to the analysis of cellular materials with empty cells to predict the structure-property relations that link the macroscopic properties to the mechanics of their underlying microstructure. Surprisingly, notwithstanding the great advantages of the composite solutions in nature, in the literature a limited number of investigations concern cellular structures having the internal volumes of the cells filled with fluids, fibers or other bulk materials as commonly happens in biology. In particular, a continuum model has not been derived and explicit formulas for the effective elastic constants and constitutive relations are currently not available. To provide a contribution in this limitedly explored research area, this thesis describes the mathematical formulation and modelling technique leading to explicit expressions for the macroscopic elastic constants and stress-strain relations of biologically inspired composite cellular materials. Two examples are included. The first deals with a regular hexagonal architecture inspired by the biological parenchyma tissue. The second concerns a mutable cellular structure, composed by mutable elongated hexagonal cells, inspired by the hygroscopic keel tissue of the ice plant Delosperma nakurense. In both cases, the predicted results are found to be in very good agreement with the available data in the literature. Then, by taking into account the benefits offered by the complex hierarchical organisation of many natural systems, the attention is focused on the potential value of adding structural hierarchy into two-dimensional composite cellular materials having a self-similar hierarchical architecture, in the first case, and different levels with different cell topologies, in the second. In contrast to the traditional cellular materials with empty cells, the analysis reveals that, in the cell-filled configuration, introducing levels of hierarchy leads to an improvement in the specific stiffness. Finally, to offer concrete and relevant tools to engineers for developing future generations of materials with enhanced performance and unusual functionalities, a novel strategy to obtain a honeycomb with mutable cells is proposed. The technique, based on the ancient Japanese art of kirigami, consists in creating a pattern of cuts into a flat sheet of starting material, which is then stretched to give a honeycomb architecture. It emerges a vast range of effective constants that the so-called kirigami honeycomb structures can be designed with, just by changing the value of the applied stretch.
8

Methodological aspects on microdialysis sampling and measurements

Abrahamsson, Pernilla January 2010 (has links)
Background:     The microdialysis (MD) technique is widely spread and used both experi­mentally and in clinical practice. The MD technique allows continuous collection of small molecules such as glucose, lactate, pyruvate and glycerol. Samples are often analysed using the CMA 600 analyser, an enzymatic and colorimetric analyser.  Data evaluating the performance of the CMA 600 analysis system and associated sample han­dling are sparse. The aim of this work was to identify sources of variability related to han­dling of microdialysis samples and sources of error associated with use of the CMA 600 analyser. Further, to develop and compare different application techniques of the micro­dialysis probes both within an organ and on the surface of an organ.  Material and Methods:  Papers I and II are mainly in vitro studies with the exception of the No Net Flux calibration method in paper I where a pig model (n=7) was used to exam­ine the true concen­tration of glucose and urea in subcutaneous tissue. Flow rate, sampling time, vial and caps material and performance of the analyser device (CMA 600) were examined. In papers III and IV normoventilated anaesthetised pigs (n=33) were used. In paper III, heart ischemia was used as intervention to compare microdialysis measurements in the myocardium with corresponding measurements on the heart surface. In paper IV, microdialysis measurements in the liver parenchyma were compared with measurements on the liver surface in associa­tion with induced liver ischemia. All animal studies were approved by the Animal Experi­mental Ethics Committee at Umeå University Sweden. Results:  In paper I we succeeded to measure true concentrations of glucose (4.4 mmol/L) and Urea (4.1 mmol/L) in subcutaneous tissue. Paper II showed that for a batch analyse of 24 samples it is preferred to store microdialysis samples in glass vials with crimp caps. For reliable results, samples should be centrifuged before analysis. Paper III showed a new application area for microdialysis sampling from the heart, i.e. surface sampling. The sur­face probe and myocardial probe (in the myocardium) showed a similar pattern for glucose, lactate and glycerol during baseline, short ischemic and long ischemic interventions. In paper IV, a similar pattern was observed as in paper III, i.e. data obtained from the probe on the liver surface showed no differences compared with data from the probe in liver paren­chyma for glucose, lactate and glycerol concentrations during baseline, ischemic and reperfusion interven­tions. Conclusion:  The MD technique is adequate for local metabolic monitoring, but requires methodological considerations before starting a new experimental serie. It is important to consider factors such as flow rate, sampling time and handling of samples in association with the analysis device chosen. The main finding in this thesis is that analyses of glucose, lactate and glycerol in samples from the heart surface and liver surface reflect concentra­tions sampled from the myocardium and liver parenchyma, respectively.
9

Avaliação dos diferentes níveis de feno de alfafa sobre parâmetros morfométricos e qualitativos do parênquima testicular e níveis séricos de testosterona em ovinos (Ovis aries) sem raça definida.

VENÂNCIO, Anna Kelly de Lima Pontes 29 May 2015 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2016-05-31T12:03:46Z No. of bitstreams: 1 Anna Kelly de Lima Pontes Venancio.pdf: 1035454 bytes, checksum: 3e71ac64c4a92627a7ead6a5f6bc4e4a (MD5) / Made available in DSpace on 2016-05-31T12:03:46Z (GMT). No. of bitstreams: 1 Anna Kelly de Lima Pontes Venancio.pdf: 1035454 bytes, checksum: 3e71ac64c4a92627a7ead6a5f6bc4e4a (MD5) Previous issue date: 2015-05-29 / Aiming to evaluate the different levels of alfalfa hay on morphometric and qualitative parameters of the testicular parenchyma and serum testosterone levels in sheep (Ovisaries) of mixed breeds, 40 sheep were used in growth, with average body weight of 26 ± 1.85 kg to approximately eight months of age. The animals were subjected to 100 days confinement (with 44 days for adaptation to management and 56 days for the administration of the experimental diets). The treatments consisted of four levels of alfalfa hay: 0%, 20%, 40% and 60%, so was maintained proportion of 60% forage for all diets. At the end of the experiment, blood collection was performed for serum testosterone measurement and weighing of animals. After slaughter, the complex testicle-epididymis were removed and individually weighed, after we calculated the GSI. Histological sections were obtained (4 mm) of testicle, which were stained with hematoxylin-Phloxine and Toluidine Blue, mounted with entelan and analyzed morphologically and morphometrically in optical microscope. The body weight, scrotal circumference and IGS showed no statistical difference neither regression effect. Among the tubular parameters, height and epithelium area suffered decreasing linear effect. The volumetric ratio, the tunic, the individual volumes and the total Leydig cells as well as blood vessels suffered increasing linear regression effect. In sperm production there was also much effect regression as statistical difference, besides the regression suffered by the rounded number of spermatids per section. Thus, it was concluded that the inclusion of alfalfa a ratio above 20% is not recommended for breeding sheep because it compromises the testicular parenchyma. / Objetivando-se avaliar os diferentes níveis de feno de alfafa sobre os parâmetros morfométricos e qualitativos do parênquima testicular e níveis séricos de testosterona em ovinos (ovis aries) sem raça definida, foram utilizados 40 carneiros em crescimento, com peso corporal médio inicial de 26 ± 1,85 kg e oito meses de idade aproximadamente. Os animais foram submetidos ao confinamento de 100 dias(sendo 44 dias para adaptação ao manejo e 56 dias para a administração das dietas experimentais). Os tratamentos foram compostos por quatro níveis de feno alfafa: 0%, 20%, 40% e 60%, de modo que foi mantida proporção de 60% de volumoso para todas as rações. Ao final do confinamento, foi realizada a coleta de sangue para dosagem de testosterona sérica e pesagem dos animais. Após o abate, os complexos testículo-epidídimo foram removidos e pesados individualmente, logo após foi calculado o índice gonadossomático. Foram obtidos cortes histológicos (4 μm) do testículo, os quais foram corados em Hematoxilina-Floxina e Azul de Toluidina, montados com Entelan e analisados morfologicamente e morfometricamente em microscópio Óptico.O peso corporal, biometria testicular e IGS não apresentaram diferença estatística nem efeito de regressão. Dentre os parâmetros tubulares, a altura e área de epitélio sofreram efeito linear decrescente. Na proporção volumétrica,a túnica própria, os volumes total e individual das células de Leydig,assim como os vasos sanguíneos sofreram efeito de regressão linear crescente. Na produção espermática também houve tanto efeito de regressão quanto diferença estatística, além da regressão sofrida pelo número de espermátides arredondadas por secção. Desta forma, foi possível concluir que a inclusão de alfafa numa proporção acima de 20% não é recomendada para ovinos reprodutores, pois compromete o parênquima testicular.
10

Ultrassonografia dos testículos e epidídimos de carneiros jovens na fase peri-puberal / Ultrasonography of testis and epididymis of youth sheep in peri-pubertal phase

AMORIM, Anny Kaline Gomes de Andrade 25 February 2010 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2016-08-01T16:15:27Z No. of bitstreams: 1 Anny Kaline Gomes Andrade Amorim.pdf: 1952052 bytes, checksum: 10023cd9df1426aca187a1cf4d10b2da (MD5) / Made available in DSpace on 2016-08-01T16:15:27Z (GMT). No. of bitstreams: 1 Anny Kaline Gomes Andrade Amorim.pdf: 1952052 bytes, checksum: 10023cd9df1426aca187a1cf4d10b2da (MD5) Previous issue date: 2010-02-25 / Aiming to evaluate the ultrasonographic appearance of testis and epididymis of sheep in pubertal and peripubertal age in order to establish normal parameters for this stage of reproductive development, 38 animals clinically healthy were used, twenty Santa Inês breed and 18 crossbred (Dorper x Santa Inês). In Santa Ines lambs, periodic evaluations of the development of weight, measurements of biometric characteristics of the testes and ultrasound examinations of the testes and epididymis were performed from 84 to 280 days of age, at intervals of 28 days. In crossbreed lambs, the same evaluations were performed from 140 to 280 days. Was used Falco 100 (Pie Medical) ultrasound scanner and linear transducer of 8.0 MHz. Scans were performed in the sagittal, transverse, frontal and oblique planes on the testis and tails of right and left epididymis of each animal, evaluating the echotexture of the testicular parenchyma, mediastinum and epididymis cauda, and measuring the thickness mediastinum and testis width. The testicular parenchyma showed homogeneous echogenicity, ranging from low to moderate, which increased in direct proportion to the age, being higher in pubertal lambs when compared to pre-pubertal. The echogenicity and thickness of the mediastinum increased with age, being classified as diffuse, moderately and highly echogenic. The tail of the epididymis showed hypoechoic appearance in relation to the testicular parenchyma. It was observed mild calcification in the testis parenchyma of five crossbreed lambs as multifocal hyperechoic images. Results of this study showed that ultrasound imaging can be used as an additional resource in the selection and evaluation morphophisiological of breeding sheep in pubertal and peripubertal age , helping to identify and monitoring changes progressive occurring in the testes and epididymis at this stage of reproductive development. / Objetivando-se avaliar o aspecto ultrassonográfico de testículos e epidídimos de ovinos em idade peri-puberal e puberal, visando o estabelecimento de parâmetros de normalidade para esta fase do desenvolvimento reprodutivo, foram utilizados 38 animais clinicamente sadios, dos quais 20 eram da raça Santa Inês e 18 mestiços (Dorper x Santa Inês). Nos cordeiros Santa Inês, avaliações periódicas do desenvolvimento ponderal, mensurações das características biométricas testiculares e exames ultrassonográficos dos testículos e epidídimos foram realizados dos 84 (desmame) aos 280 dias de idade, em intervalos de 28 dias. Nos mestiços, as mesmas avaliações foram realizadas dos 140 aos 280 dias. Foi utilizado aparelho de ultrassom Falco 100 (Pie Medical) e transdutor linear de 8,0 MHz. As varreduras foram realizadas nos planos sagital, transversal, frontal e oblíquo dos testículos e caudas dos epidídimos direito e esquerdo de cada animal, avaliando-se a ecotextura do parênquima testicular, mediastino e cauda do epidídimo, e aferindo-se a espessura do mediastino e a largura testicular. O parênquima testicular apresentou ecogenicidade homogênea, variando de baixa a moderada, que aumentou em proporção direta com a idade, sendo maior nos cordeiros púberes quando comparados aos pré-púberes. A ecogenicidade e espessura do mediastino também aumentaram com a idade, sendo classificado em difuso, moderadamente e altamente ecogênico. A cauda do epidídimo apresentou aspecto hipoecóico em relação ao parênquima testicular. Observaram-se calcificações de grau leve no parênquima testicular de cinco dos cordeiros mestiços avaliados, as quais foram visibilizadas como imagens multifocais hiperecóicas. Concluiu-se que a ultrassonografia por imagem pode ser utilizada como recurso complementar na seleção e avaliação morfofisiológica de reprodutores ovinos em idade puberal e peri-puberal, contribuindo na identificação e monitoramento das mudanças progressivas que ocorrem nos testículos e estruturas relacionadas nesta fase do desenvolvimento reprodutivo.

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