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Abstract  PbZrO3 powders have been prepared by an alkoxide-based sol–gel route, starting from lead acetate, zirconium n-butoxide, and n-butanol as a solvent, and hydrolysed with different amounts of water in neutral and alkaline medium. The local environment of Zr and Pb atoms was pursued from the sol to the dried (150 °C) and heated (400 °C) powders, by extended x-ray absorption fine structure (EXAFS). The analysis of the sol revealed links between Pb and Zr, and even more links between Zr and Zr. The metal neighbourhoods in the dried powders are not influenced by the hydrolysis conditions. Pb-Zr correlations are gradually lost from the sol to the dried and heated powders, while the loss of Zr–Zr correlations is considerably lower. [ABSTRACT FROM AUTHOR]

Abstract  Porous ceramics are of interest for ultrasonic transducer applications. Porosity allows to decrease acoustical impedance, thus improving transfer of acoustical energy to water or biological tissues. For underwater applications, the dhgh figure of merit can also be improved as compared to dense materials. In the case of high frequency transducers, namely for high resolution medical imaging, thick film technology can be used. The active films are generally porous and this porosity must be controlled. An unpoled porous PZT substrate is also shown to be an interesting solution since it can be used in a screen-printing process and as a backing for the transducer. This paper describes the fabrication process to obtain such materials, presents microstructure analysis as well as functional properties of materials. Modelling is also performed and results are compared to measurements. Finally, transducer issues are addressed through modelling and design of several configurations. The key parameters are identified and their effect on transducer performance is discussed. A comparison with dense materials is performed and results are discussed to highlight in which cases porous piezoceramics can improve transducer performance, and improvements are quantified. [ABSTRACT FROM AUTHOR]

The cell membrane of ram spermatozoa is more sensitive to the freezing process than in other species due to its composition. As a result, the quality and viability of frozen thawed ram spermatozoa are often poor, which together with the specific structure of the ewe's cervix are the main reasons for lower fertility in ewes after intracervical insemination. In the present study we investigated the effects of semen centrifugation through a single layer of a species-specific colloid (Androcoll-O) on post-thaw quality of ram spermatozoa. Motility, viability and morphology were analysed 0, 6, 12 and 24 h after thawing. DNA fragmentation index (%DFI) of the samples was assessed 0 h after thawing, by SCSA™. Membrane and acrosome integrity of spermatozoa were analysed by Sybr-14/PI/PNA test 0 h after thawing. The proportion of motile spermatozoa was significantly higher in SLC - selected samples in comparison to control (not SLC - selected) samples at 0, 6, 12 (P < 0.001) and 24 h (P < 0.05). The proportion of viable spermatozoa was also significantly higher in SLC - selected samples in comparison to control samples at all times (P < 0.001). The proportion of abnormal acrosomes and morphologically abnormal spermatozoa (MAS) were significantly lower in SLC - selected samples compared to control samples at all times (P < 0.001). Analysis of chromatin stability revealed significantly lower %DFI values in SLC - selected samples compared to control samples (P < 0.001). The SYBR-14/PI/PNA test also revealed significantly better values in SLC - selected compared to control samples (P < 0.05). In conclusion, single layer colloid centrifugation significantly improved post-thaw quality and longevity of ram spermatozoa, making it suitable for artificial insemination initiatives., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Reasons for Performing Study: The interest in donkeys is growing due to their integration in the systems of ecological farming, among other reasons., Objectives: Due to limited reports on leptin concentrations in donkeys, the aim of the present study was to examine age-dependent and seasonal changes in the circulating leptin concentration in female donkeys (jennies) and thus contribute to knowledge about the physiological characteristics of this species., Study Design: Prospective longitudinal study., Methods: The study was performed over a year (September 2008 to September 2009) on 20 yearling and young adult (pregnant, lactating or barren) jennies aged 1-5 years at the onset of the study; the animals were kept on pasture from May to September and stabled for the rest of the year. Blood samples were taken monthly and analysed for serum leptin concentrations by a commercial radioimmunoassay kit., Results: Circulating leptin concentrations in studied jennies were lower than those reported for donkeys and horses. Despite the tendency for lower values in yearling vs. young adult jennies, the age range of the examined animals was insufficient to confirm any age-related leptin variations. Significant seasonal leptin fluctuations with peak levels in late spring and the lowest levels in autumn months, correlated with photoperiod, were detected in yearling, barren as well as pregnant jennies. Therefore, it was impossible to identify any effects of gestation or lactation on leptin concentrations of jennies., Conclusions: The results of this study cannot be used as evidence of a causal relationship between the photoperiod and seasonal circulating leptin fluctuations in donkeys, but could reflect changes induced by various external or internal factors enabling adaptations of grazing animals in variable submediterranean environments., (© 2014 EVJ Ltd.)

Superoxide dismutase (SOD), total antioxidant capacity (TAC), and thiobarbituric acid reactive substances (TBARS) in seminal plasma were evaluated on the basis of receiver operating characteristics (ROC) analysis as predictors for distinguishing satisfactory from unsatisfactory boar semen samples after storage. SOD on day 0 correlated significantly with progressive motility (r=-0.686; P<0.05) and viability (r=-0.513; P<0.05) after storage; TBARS correlated only with motility (r=-0.480; P<0.05). Semen samples that, after 3 days of storage, fulfilled all criteria for semen characteristics (viability>85%, motility>70%, progressive motility>25%, and normal morphology>50%) had significantly lower SOD levels on the day 0 than those with at least one criterion not fulfilled (P<0.05) following storage. SOD levels of less than 1.05 U/mL predicted with 87.5% accuracy that fresh semen will suit the requirements for satisfactory semen characteristics after storage, while semen with SOD levels higher than 1.05 U/mL will not fulfill with 100% accuracy at least one semen characteristic after storage. These results support the proposal that SOD in fresh boar semen can be used as a predictor of semen quality after storage.

The objective of this study was to evaluate metabolic disorders and oxidative stress in dairy heifers during the transition period. Possible relationships between lipid mobilisation indicators and oxidative stress markers were investigated as well. Nineteen dairy heifers were included in the study. Blood samples were collected at the time of estrus synchronisation in heifers, at insemination, three weeks after insemination, one week before calving, at calving and 1, 2, 4 and 8 weeks postpartum. Common metabolic parameters, beta-hydroxybutyrate (BHB), free fatty acids (FFA), paraoxonase-1 (PON1) activity and total antioxidative status (TAS) were analysed. Around insemination, no significant difference was observed in the majority of tested parameters (P>0.05). However, the transition period markedly affected the concentration of triglycerides, total cholesterol, HDL-C, BHB, FFA, TAS and PON1activity. Positive correlations between PON1 activity and total cholesterol, HDL-C and triglycerides were noted but inverse correlations with FFA, BHB and bilirubin were found indicating that PON1 activity changed with lipid metabolism and was influenced by negative energy balance. These findings suggest that lipid mobilisation and oxidative stress are part of a complex metabolic adaptation to low energy balance which reaches equilibrium later in advanced lactation., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The aim of this study was to address the question whether changes in boar semen quality after short-term storage could be predicted on the basis of standard semen parameters and TNF-α level determined on the day of semen collection under commercial conditions. Progressive motility showed the highest positive correlation with morphology on day 0 of collection, and progressive motility on day 3 (P < 0.05) showed a negative correlation with acrosome abnormalities (P < 0.05). According to the area under receiver operating characteristics (ROC) curves (AUCs), progressive motility could also be used in predicting semen quality after 3 days of storage (AUC > 0.5; P < 0.05). TNF-α in seminal plasma is the only parameter measured on day 0 to show a significant correlation with the percentage of viable spermatozoa after 3 days of semen storage (r = 0.495, P < 0.05). ROC analysis shows that TNF-α level is helpful in discriminating viability outcome after semen storage (AUC = 0.94, P < 0.001). We can predict with 92.35% certainty that fresh semen samples with more than 150 pg/ml of TNF-α in the seminal plasma will retain more than 85% of viable spermatozoa after 3 days of storage. Thus, TNF-α can contribute to predicting the quality of short-term stored semen.

A significant part of the uniformity degradation in the acquired hyperspectral images can be attributed to the coregistration distortions and spectrally and spatially dependent resolution arising from the misalignments and the operation principle of the spectrograph based hyperspectral imaging system. The aim of this study was the development and validation of a practical method for characterization of the geometric coregistration distortions and position dependent resolution. The proposed method is based on modeling the imaging system response to several affordable reference objects. The results of the characterization can be used for calibration of the acquired images or as a tool for assessment of the expected errors in various hyperspectral imaging systems.

Electrophoretic deposition (EPD) is an attractive method for the fabrication of a few tens of micrometer-thick piezoelectric layers on complex-shape substrates that are used for manufacturing high-frequency transducers. Niobium-doped lead-zirconate titanate (PZT Nb) particles were stabilized in ethanol using poly(acrylic acid) (PAA). With Fourier-transform infrared spectroscopy (FT-IR), we found that the deprotonated carboxylic group from the PAA is coordinated with the metal in the perovskite PZT Nb structure, resulting in a stable ethanol-based suspension. The hydroxyl group from the polyvinyl butyral added into the suspension to prevent the formation of cracks in the as-deposited layer did not interact with the PAA-covered PZT Nb particles. PVB acts as a free polymer in ethanol-based suspensions. The electrophoretic deposition of micro- and nanometer-sized PZT Nb particles from ethanol-based suspensions onto electroded alumina substrates was attempted in order to obtain uniform, crack-free deposits. The interactions between the PZT Nb particles, the PAA, and the PVB in ethanol will be discussed and related to the properties of the suspensions, the deposition yield and the morphology of the as-deposited PZT Nb thick film.

Among the variety of available hyperspectral imaging systems, the line-scan technique stands out for its short acquisition time and good signal-to-noise ratio. However, due to imperfections in the camera lens and, in particular, optical components of the imaging spectrograph, the acquired images are spatially and spectrally distorted, which can significantly degrade the accuracy of the subsequent hyperspectral image analysis. In this work, we propose and evaluate an automated method for correction of spatial and spectral distortions introduced by a line-scan hyperspectral imaging system operating in the short wavelength infrared (SWIR) spectral range from 1000 nm to 2500 nm. The proposed method is based on non-rigid registration of the distorted and reference images corresponding to two passive calibration objects. The results of the validation show that the proposed method is accurate, efficient, and applicable for calibration of line-scan hyperspectral imaging systems. Moreover, the design of the method and of the calibration objects allows integration with systems operating in diffuse reflectance or transmittance modes.

This article describes some of our work on ₀.₆₅Pb(Mg₁/₃Nb(₂/₃)O₃-₀.₃₅PbTiO₃ (0.65PMN-0.35PT) thick films printed on alumina substrates. These thick films, with the nominal composition ₀.₆₅Pb(Mg₁/₃Nb(₂/₃)O₃-₀.₃₅PbTiO₃, were produced by screen-printing and firing a paste prepared from an organic vehicle and pre-reacted fine particles of avery chemically homogeneous powder. To improve the adhesion of the 0.65PMN-0.35PT to the platinized alumina substrate,a Pb(Zr₀.₅₃Ti₀.₄₇)O₃ layer was deposited between the electrode and the substrate. The samples were then sintered at 950 °C for 2 h with various amounts of packing powder on the alumina (Al₂O₃) substrates. The sintering procedure was optimized to obtain dense 0.65PMN-0.35PT films. The films were then characterized using scanning electron microscopy as well as measurements of the dielectric and piezoelectric constants.The electrostrictive behavior of the 0.65PMN-0.35PT thick films was investigated using an atomic force microscope(AFM). Finally, substrate-free, large-displacement bending type actuators were prepared and characterized, and the normalized displacement (i.e., the displacement per unit length) of the actuators was determined to be 55 μm/cm at 3.6 kV/cm.

Piezoelectric 0.65Pb(Mg(1/3)Nb(2/3))O(3)-0.35PbTiO(3) (PMN-35PT) thick film with a thickness of approximately 12 µm has been deposited on the platinum buffered Si substrate via a sol-gel composite method. The separation of the film from the substrate was achieved using a wet chemical method. The lifted-off PMN-35PT thick film exhibited good dielectric and ferroelectric properties. At 1 kHz, the dielectric constant and the dielectric loss were 3,326 and 0.037, respectively, while the remnant polarization was 30.0 µC/cm(2). A high frequency single element acoustic transducer fabricated with this film showed a bandwidth at -6 dB of 63.6% at 110 MHz.

In this work we investigated the chemical composition and structure of (K0.5Na0.5)NbO3 (KNN) single crystals grown by the solid state crystal growth method. The optical, scanning, and transmission electron microscopies were employed for the analysis of the chemical homogeneity and domain structure of the KNN crystal. No compositional inhomogeneities within experimental error were encountered in the KNN single crystals. The domain structure of the KNN single crystal, with a monoclinic unit cell, is composed of large 90 degrees domains of up to 100 microm width, which further consist of smaller 180 degrees domains with widths from 50 to 300 nm.

Phonons in both ceramic samples KNbO(3) (KN) and K(0.5)Na(0.5)NbO(3) (KNN-50) were investigated from 10 to 900 K by means of Raman, infrared, and THz spectroscopy. First-order transitions from cubic to tetragonal phases were detected at about 755 K (in KN) and 710 K (in KNN-50), where the first component of the polarization appears. Transitions from the tetragonal to the orthorhombic phases take place around 510 and 475 K, respectively. The last transitions from orthorhombic to rhombohedral phases are strongly first-order type. T(C) is shifted from 200 K in KN to about 90 K in KNN-50. All Raman active modes below 200 cm(-1). disappear in KN but not in KNN-50. The overdamped soft mode present at high temperatures in the THz range changes its dielectric strength at each phase transition (when the corresponding component jumps to higher frequencies) and abruptly disappears from THz spectra in the rhombohedral phase, because it stiffens up to 200 cm(-1). This mode has lower frequency and higher dielectric strength in KNN-50.

This paper deals with the transmission of acoustic waves through multilayered piezoelectric materials. It is modeled in an octet formalism via the hybrid matrix of the structure. The theoretical evolution with the angle and frequency of the transmission coefficients of ultrasonic plane waves propagating through a partially depoled PZT plate is compared to finite element calculations showing that both methods are in very good agreement. The model is then used to study a periodic stack of 0.65 PMN-0.35 PT/0.90 PMN-0.10 PT layers. The transmission spectra are interpreted in terms of a dispersive behavior of the critical angles of longitudinal and transverse waves, and band gap structures are analysed. Transmission measurements confirm the theoretical calculations and deliver an experimental validation of the model.

To determine seasonal changes in circulating leptin concentrations, as well as leptin fluctuations in various patterns of seasonal ovarian activity, blood samples were taken in 107 Lipizzan fillies aged 1-4 years over the whole year from January to December. Serum concentrations were measured in samples obtained once a month (leptin) or twice a month (progesterone), and evaluated with respect to the age of animals (yearlings, 2-, 3- and 4-year olds) and the pattern of ovarian activity (anoestrous, seasonal cycle, prolonged cyclicity, continuous cyclicity). The mean and monthly leptin concentrations in 3- and 4-year olds were significantly higher than in yearlings and 2-year olds (p < 0.001). Circulating leptin levels in 3- and 4-year olds increased significantly in summer, to peak in August and then decline significantly (p < 0.001) in autumn. The fluctuations in younger fillies were less evident. The highest mean serum leptin concentrations were observed in fillies exhibiting continuous cyclicity and the lowest in those, exhibiting seasonal cyclicity (p < 0.001). In anoestrous fillies, leptin concentrations were lower than in fillies with prolonged or continuous cyclicity but higher than in fillies with seasonal cyclic activity (p > 0.05).

In the present study, a new one-step real-time reverse transcription-polymerase chain reaction (RT-PCR) strategy with minor-groove-binder (MGB) technology for the detection of EAV from 40 semen samples of Slovenian carrier stallions was tested. A novel MGB probe (EAVMGBpr) and a reverse primer (EAV-R) based on the multiple sequence alignment of 49 different EAV strain sequences of the highly conserved ORF7 (nucleocapsid gene) were designed. The performance of the assay was compared with different molecular detection methods. Three different primer pairs targeting the ORF1b and ORF7 were used, respectively. The real-time RT-PCR assay was at least 2 log(10) more sensitive than the classical RT-PCR and at least 1 log(10) more sensitive than the primer set used in the semi-nested PCR. The specificities of the amplification reactions were confirmed with biotinylated probes in the PCR-enzyme-linked immunosorbent assay (PCR-ELISA). Under the conditions described in our study, the sensitivity of the real-time RT-PCR was found to be superior to the PCR-ELISA assay. Thus, while the PCR-ELISA method was found to be both relatively demanding and time consuming, better sensitivity coupled with high specificity and speed of the assay makes the real-time RT-PCR a valuable tool for diagnosis of EAV infection.

In this work, the results of compositional and microstructural analysis of lead zirconate titanate--lanthanum ruthenate thin film structures prepared by chemical solution deposition are discussed. The cross-section transmission electron microscope (TEM) micrographs of the La-Ru-O film deposited on a SiO2/Si substrate and annealed at 700 degrees C revealed RuO2 crystals embedded in a glassy silicate matrix. When the La-Ru-O film was deposited on a Pt/TiO2/SiO2/Si substrate, RuO2 and La4Ru6O19 crystallized after annealing at 700 degrees C. After firing at 550 degrees C randomly oriented lead zirconate titanate (PZT) thin films crystallized on the La-Ru-O/SiO2/Si substrate, while on La-Ru-O/Pt/TiO2/SiO2/Si substrates PZT thin films with (111) preferred orientation were obtained. No diffusion of the Ru atoms in the PZT film was found. Ferroelectric response of PZT thin films on these substrates is shown in comparison with the PZT film deposited directly on the Pt/TiO2/SiO2/Si substrate without a La-Ru-O layer., ((c) 2007 Wiley Periodicals, Inc.)

A screen-printed PZT thick film with a final thickness of about 40 microm was deposited on a porous PZT substrate to obtain an integrated structure for ultrasonic transducer applications. This process makes it possible to decrease the number of steps in the fabrication of high-frequency, single-element transducers. The porous PZT substrates allow high acoustic impedance and attenuation to be obtained, satisfying transducer backing requirements for medical imaging. The piezoelectric thick films deliver high electromechanical performance, comparable to that of standard bulk ceramics (thickness coupling factor over 45%). Based on these structures, high-frequency transducers with a center frequency of about 25 MHz were produced and characterized. As a result, good sensitivity and axial resolution were obtained in comparison with similar transducers integrating a lead titanate (PT) disk as active material. The two transducers were integrated into a high-frequency imaging system, and comparative skin images are shown.

Reasons for Performing Study: The onset of puberty and duration of seasonal cyclicity in Lipizzan fillies and young mares have been determined mostly by empirical data, but very little is known about the hormonal changes at puberty and during the seasonal cyclicity in this breed., Objectives: To determine the onset of puberty and the course of the cyclicity in young Lipizzan mares from age 1-4 years., Methods: Blood samples were collected twice a month for 2 years from 46 Lipizzan fillies age 1-4 years. Progesterone concentrations, indicating ovarian activity, were measured using an EIA kit. Values above 6.4 nmol/l were taken to indicate luteal phase and those below 3.4 nmol/l, oestrus., Results: Fifty percent of Lipizzan fillies entered puberty during the first spring after their birth at mean +/- s.e. age 15.25 +/- 0.31 months and 50% during the second spring, at age 25.2 +/- 0.57 months. For several fillies of all ages, manifesting anoestrus during the winter months, the oestrus started in March and reached a peak in June to September. The duration of the oestrus activity was age-dependent, at 2.37 +/- 0.62 months in yearlings and 8.56 +/- 0.46 months in fillies age 4 years. In December, >50% of fillies age 2-4 years still exhibited oestrus activity and some entered anoestrus in January the following year. A small proportion of fillies age 3-4 years remained cyclic during the whole year, indicating that factors other than photoperiod can be involved in regulating seasonal cyclicity., Conclusions and Potential Relevance: Our results demonstrate the influence of seasonal factors on the onset of puberty and on the course of oestrus activity in the majority of Lipizzan fillies. However, certain exceptions were also demonstrated but reasons for the prolonged periods of oestrus activity in some Lipizzan fillies were not identified, and the role of the hormone leptin should be studied in future investigations.

Aim: To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality., Methods: The accuracy of the spectrophotometric application of the resazurin reduction assay was assessed using receiver operating characteristic (ROC) analysis., Results: Areas under ROC curves (AUC) for motile sperm concentration and sperm index (SI) (sperm concentration multiplied by the square root of percentage sperm motility multiplied by the percentage normal sperm morphology) were 0.922. The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A610 = 0.209, where high sensitivity (94.1%) and specificity (91.7%) were calculated. The assay was less accurate when motile sperm concentration was used as the criterion value, yielding sensitivity of 88.2% and specificity of 87.5%, respectively. Likelihood ratios (LR) indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI, whereas in the case of motile sperm concentration, the LR was calculated to be 7.06., Conclusion: These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.

Benign prostatic hyperplasia was diagnosed in an American Staffordshire Terrier of high breeding value presenting concurrent haematuria. Castration as a treatment was synchronized with the oestrus cycle of a bitch selected for insemination. After castration the cauda epididymis was flushed with Gent semen extender and collected spermatozoa were filtered and analysed by Hamilton Thorn computer assisted sperm analysis. A total of 7 ml semen containing 742 x 10(6) spermatozoa with 76.5% mean motility was used for insemination. Intravaginal insemination of the bitch was performed with an insemination catheter for dogs (Kruuse, Marslev, Denmark) on the day when plasma progesterone levels reached 9.9 ng/ml. Normal pregnancy without complications resulted in eight live-born puppies 63 days after insemination. This is the first report of a normal pregnancy and birth of puppies from a bitch inseminated with epididymal semen obtained from a dog affected by benign prostate hyperplasia.

Using electron microscopy, K0.5Na0.5NbO3 (KNN) ceramics sintered at 1030 degrees C for 8 h and 1100 degrees C for 2 and 24 h was studied. The scanning electron microscopy and X-ray spectrometry revealed that the materials consisted of a matrix phase in which the (Na+K)/Nb ratio corresponded closely to the nominal composition and a small amount of Nb-rich secondary phase. A bimodal microstructure of cube-shaped grains was revealed in the fracture and thermally-etched surfaces of the KNN. In the ceramics sintered at 1100 degrees C, the larger grains (up to 30 mum across), contained angular trapped pores. The transmission electron microscopy analysis revealed that the crystal planes of the grains bordering the intragranular pore faces were of the {100} family with respect to the simple perovskite cell. Ferroelectric domains were observed in the grains of this material.

Reasons for Performing Study: The success rate of artificial insemination following the freezing of stallion semen is limited; therefore, improving the stallion semen quality after the freezing and thawing process is a necessary objective., Objectives: To investigate the influence of glass bead column separation on the freezability of stallion semen., Hypothesis: Glass beads in a column separator remove damaged and dead spermatozoa in the ejaculate during centrifugation., Methods: In total, 50 ejaculates from 6 Lipizzaner stallions were studied. Each ejaculate was divided into 2 parts, one half processed following standard procedure and the second half used for the column separation procedure. After freezing, semen quality was evaluated using standard tests for motility, morphology and viability of semen., Results: Motility and progressive motility of the column-separated (CS) semen were significantly higher (P < 0.001) before freezing and immediately, 24 and 48 h after thawing. A significant increase (P < 0.001) in the percentage of hypoosmotic positive spermatozoa was observed in CS samples. The percentage of total morphological changes in the separated samples before and after freezing was significantly lower (P < 0.001) compared with samples prepared using the standard procedure. A substantial decrease (P < 0.001) was found in the percentage of spermatozoa with damaged acrosomes. However, the percentage of spermatozoa with coiled tails was increased in the separated samples (P < 0.001)., Conclusions: Column separation before freezing has a positive effect on the quality of thawed equine semen., Potential Relevance: The quality of CS frozen/thawed samples indicates their potential use for increasing insemination success in mares.

The resazurin reduction assay depends on the ability of metabolically active cells to reduce the resazurin redox dye to resorufin. In the present study we applied and made a diagnostic evaluation of a spectrophotometric application of the resazurin reduction assay to assess the colour change of resazurin reduction in butanol extracted colour to evaluate boar semen quality. Forty-one samples of boar semen from various breeds were included in the study. The absorption peaks for resazurin and resorufin were found to be 610 and 575 nm, respectively. Absorbance at 610 nm, where the minimum overlap of the two peaks was observed, was used in further analysis. Spearman rank correlation analysis was used to determine the correlation between the resazurin reduction assay and various semen parameters. The highest correlations were observed with the concentration of motile spermatozoa (r = -0.841; p < 0.001), sperm concentration (r = -0.833; p < 0.001), sperm index (-0.826; p < 0.001) and concentration of viable spermatozoa (r = -0.763; p < 0.001). Sensitivity and specificity, at 94.1 and 91.7%, respectively, indicate that the present test is highly accurate in discriminating between the samples according to the sperm index. When motile sperm concentration was used to distinguish between good and poor samples, high sensitivity (93.6%) was also found, whereas the test was only moderately, 80%, specific. The stability of butanol extracts in terms of A610 at different times of measurement confirmed that the resazurin reduction could be spectrophotometrically measured within 7 days from the time of assay performance, making the assay much more useful. Based on these results, the assay could be used as an additional tool for evaluating the quality of boar semen.

Young boars were treated with propiothiouracil to induce hypothyroidism to examine its effects on postnatal testicular development. Treatments with 0.1% 4-propyl-2-thiouracil (PTU) in drinking water started after weaning, at 3 weeks of age and all boars were severely hypothyroid at 6 weeks of age as determined by measuring T3 and T4 in blood plasma. Boars were castrated at different ages up to 20 weeks and their testes used for histological and immunohistochemical analyses. Although small but significant reduction in testis weight was observed from 8 to 12 weeks of age, this was not accompanied by significant difference in testicular volume. By 20 weeks of age, at the beginning of puberty, the differences in testis weights between control and treated groups of boars disappeared suggesting there is no lasting effect of hypothyroidism on postnatal development of boar testis. Immunohistochemical staining was used to determine the presence of molecular markers in both Sertoli and Leydig cells. Again, there were no differences between testes from control and treated boars in the pattern or intensity of immunostaining using antibodies against 3beta-hydroxysteroid dehydrogenase, antimullerian hormone or proliferating cell nuclear antigen (PCNA). Immunostaining with antibodies against PCNA showed interesting results as it was observed that Sertoli cells still express this marker of proliferating cells at 14 weeks of age, later than previously suggested cessation of Sertoli cell proliferation. This study suggests that hypothyroidism in boars does not have similar effects on postnatal testis development as reported in some other species.

Microcystin-LR is the most frequently studied cyclic heptapeptide produced by different genera of cyanobacteria and is hepatotoxic to livestock and human populations. The adverse effects of microcystin-LR on morphology and cytoskeletal elements in different stages of early embryonal development have been studied in vitro. Embryos and whole embryo cultures have been exposed to microcystin-LR (10-100 microM). Actin filaments were visualized by fluorescence staining and the microtubular network labelled by immunostaining. Growth, development and cytoskeleton organization of the embryos embedded in zona pellucida are not affected by microcystin-LR in concentrations up to 100 microM, while whole embryo cell cultures are affected by the presence of microcystin-LR in the culture medium. High microcystin-LR concentrations (100 microM) cause cells to be detached and destroyed, while lower concentrations (10-20 microM) profoundly affect actin and microtubule organization. These effects are confirmed also by the presence of transformed microcystin-LR in all the media at the lowest concentrations. It seems that the changes to the cells are far more serious than that expressed in cell morphology. From our experiments we conclude that the presence of zona pellucida is an effective way of embryo protection against xenobiotics like microcystin-LR.

Total and differential leucocyte counts (lymphocytes, neutrophils, monocytes, eosinophils and basophils) were measured in 140 stallions, 101 mares and 25 foals of Lipizzan breed. The values fell in the normal ranges for warm-blooded horses. Differences between mares and stallions were not significant with the exception of foals, having higher white blood cell, neutrophil, lymphocyte, monocyte and basophil values in females than in males. Foals exhibited an age-related increase of total leucocyte count during the first 4 months of life, accompanied by a decrease in neutrophil and increase in lymphocyte and eosinophil counts. In mares and stallions, the total number of leucocytes, lymphocytes, monocytes and basophils significantly decreased but the number of neutrophils and eosinophils remained almost unchanged with age gain.

Chemical solution-deposited thin films of PbZr(0.53)Ti(0.47)O(3)/La(0.5)Sr(0.5)CoO(3) on Pt/TiO(2)/SiO(2)/Si substrates have been investigated by dynamic SIMS. The PbZr(0.53)Ti(0.47)O(3) (PZT) is intended to serve as a ferroelectric layer for microelectronic or microelectromechanical applications; conducting La(0.5)Sr(0.5)CoO(3) (LSCO) is a buffer layer intended to eliminate fatigue effects which usually occur at the Pt/PZT interface. Depth profiles of the main components were obtained and revealed that significant diffusion occurred during the deposition and crystallisation processes. Two types of sample, with different thickness of PZT and different types of poly(vinyl alcohol) (PVA) added to the LSCO precursor, were investigated.

Haematological parameters [red blood cell count (RBC), white blood cell count (WBC), packed cell volume (PCV), haemoglobin concentration, mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC)] in resting Lipizzan horses were determined for 143 stallions, 104 mares and 25 foals. The mean RBC and WBC values in Lipizzans were in the lower part of the normal range for warm-blooded horses. The mean PCV, MCV and MCH values were higher, but the mean haemoglobin concentration and MCHC values were lower than reported for other warm-blooded horses. In foals, the mean RBC, WBC, PCV, haemoglobin concentration and MCHC values were higher, whereas MCV and MCH were lower than in older animals. Results indicating a significant decrease in WBC (P < 0.01) and an increase in MCV, MCH and MCHC (P < 0.05) with increasing age are consistent with some other reports on warm-blooded horses. The age-related variations in RBC and PCV were less marked. Contrary to some reports, RBC (P < 0.01), WBC and haemoglobin concentration (P < 0.001) were higher in Lipizzan stallions than in mares, but differences in MCHC, MCH and MCV were insignificant. The specific haematological values determined in Lipizzans are presumably a result of selection and should be taken into consideration when dealing with this race of horses.

The aim of this study was to investigate the role of P-glycoprotein (P-gp) in the adrenal gland. It has been presumed that P-gp, rather than being involved in physiological cortisol secretion, plays a role in protecting the adrenacortical cells from xenobiotics. To explore this a study was performed on perfused bovine adrenal glands. Individual experimental groups were perfused with either a selective P-gp blocker (valspodar) alone, with a xenobiotic (mitotane or doxorubicin) alone or with both valspodar and a xenobiotic. The cumulative amounts of cortisol secreted in each individual group were calculated and the two-sample t-test was used to compare the mean values of cumulative amounts. The mean value of cortisol secreted from the group of adrenals perfused with the P-gp blocker was not significantly different from that of the control group. Treatment with either mitotane or doxorubicin decreased the amount of cortisol secreted but not significantly when compared to the amount of cortisol secreted in basal conditions. However, treatment with the P-gp blocker valspodar in addition to either mitotane or doxorubicin significantly decreased cortisol secreted compared to the amount of cortisol secreted by the glands treated with either mitotane (p=0.009) or doxorubicin (p=0.017) alone. The regressive changes discovered in all experimental groups were most prominent when valspodar was used with either mitotane or doxorubicin. We found that P-gp blockade increases by xenobiotic (mitotane and doxorubicin)-induced damage of adrenocortical cells, which points to a role of P-gp in the protection of adrenal gland from xenobiotics.

The subchronic effects of cyanobacterial lyophilizate (CL) containing microcystins on liver were investigated in female New Zealand rabbits. Sterilised CL containing microcystins was injected i.p. Liver toxicity was assessed by histological examination of liver samples. Non-invasive magnetic resonance imaging (MRI) of liver was also performed in order to assess changes in the homogeneity of liver tissue. Subchronical intoxication with microcystins caused morphological changes of liver tissue that were also detected by use of MRI. Histological analysis showed that changes seen on MRI represent liver injury characterised with fatty infiltration and periportal fibrosis. This demonstrates that subchronic exposure to microcystins can lead to liver degeneration, which can easily be detected in vivo by use of MRI.

Thyroid hormones appear to determine adult testis size in rodents by regulating the period of Sertoli cell proliferation in the neonatal period. In the present study, the correlation between neonatal thyroid hormone levels (T3 and thyroxin, T4) and postpubertal testis size in Simental bulls was examined. T3 and T4 levels were measured in blood plasma from 35 calves immediately after their arrival at the AI centre at age 3-6 months. Testis size (height and width) was measured at 12 months of age in the same live animals. A significant negative correlation (r = -0.55; p < or = 0.001) was found between T4 and calculated testicular volume using either the Pearson correlation test or linear regression analysis, while the levels of T3 and testis volume showed a negative correlation, although this did not reach statistical significance (r = -0.20, p < or = 0.05). The results of this study suggest, therefore, that neonatal thyroid hormone levels might have the same effect on testicular size in cattle as they do in rodents.