Effect pf genotype, age of dams, litter size, birth weight and rams on morphological parameters of the placenta in sheep

It is well established that especially in prolific ewes the mortality rates are high in lambs with low birth weights and that after birth the absolute growth rates are lower in the surviving light lambs than in the heavier lambs. Differences in the prenatal placental development as the feto-maternal connection could be one of the reasons for this effect. The aim of the present study was to ascertain primary data for the placenta characteristics. Therefore three different genotypes which varied in litter size and weight of all born lambs were studied. In 197 placentas the weight, the number of cotyledones, the diameter of the cotyledones and the weight of ten cotyledones were determined. The total weight of all cotyledones and surface area of the cotyledones (the feto-maternal contact area) were calculated. The effects of the breed, the age of the dams (1.5-7.5 years), the litter size (1-4), the weight of all born lambs (5 classes between 3 and 15 kg) and the ram were tested with the ANOVA/MANOVA procedure (co-variable = weight of the dams before mating). Litter size and weight of all born lambs influenced significantly the morphologicaly parameters of the placenta. In the examined genotypes the placenta weight increased from a minimum of 500 g to 1100 g and the surface of the cotyledones grew from 200 cm2 to 350 cm2 with increasing litter size and increasing weight of all born lambs. This seems to be a maternal compensation mechanism for the raising fetal requirements. With the increase of the litter size the surface area of the cotyledones for each lamb decreases because the possible placental compensation mechanism collapses. This could be a reason for low birth weights and increasing deaths of lambs. A possible influence of the genotype on the characteristics of the placentas is discussed by considering the litter size and the condition of the ewe. Paternal effects were not found.     

Beating crystallization in glass-forming metals by millisecond heating and processing

The development of metal alloys that form glasses at modest cooling rates has stimulated broad scientific and technological interest. However, intervening crystallization of the liquid in even the most robust bulk metallic glass-formers is orders of magnitude faster than in many common polymers and silicate glass-forming liquids. Crystallization limits experimental studies of the undercooled liquid and hampers efforts to plastically process metallic glasses. We have developed a method to rapidly and uniformly heat a metallic glass at rates of 10(6) kelvin per second to temperatures spanning the undercooled liquid region. Liquid properties are subsequently measured on millisecond time scales at previously inaccessible temperatures under near-adiabatic conditions. Rapid thermoplastic forming of the undercooled liquid into complex net shapes is implemented under rheological conditions typically used in molding of plastics. By operating in the millisecond regime, we are able to "beat" the intervening crystallization and successfully process even marginal glass-forming alloys with very limited stability against crystallization that are not processable by conventional heating.     

Bacterial community structure in lake sediments of microcosms contaminated with nonylphenol

The impact of nonylphenol, an estrogenic degradation product of alkylphenol polyethoxylates, on the bacterial community structure in contaminated sediments of aquatic microcosms was investigated over a period of 20 weeks using a 16S rDNA-based molecular phylogenetic approach. All microcosms showeda strong seasonal fluctuation of the dominant as well as the active bacterial microflora independent of their degree of contamination with nonylphenol. These changes were correlated with the dynamic of the total organic carbon content (TOC), ranging from 4–39 g/kg sediment dry weight and the redox potential in the sediment. Even at the highest observed nonylphenol concentration (3.4 mg/kg sediment dry weight) the bacterial community structure was mostly unchanged.     

Withdrawn: Effects of OmniGen‐AF on blood neutrophil gene expression,milk leucocyte populations and production performance of early lactating dairy cows

The following article from Journal of Animal Physiology and Animal Nutrition, ‘Effects of OmniGen‐AF on blood neutrophil gene expression, milk leucocyte populations and production performance of early lactating dairy cows’ by R. D. Schramm, S. L. Shields, P. Rezamand, K. S. Seo, M. A. McGuire, published online on 6th July 2011 in Wiley Online Library ( wileyonlinelibrary.com ), has been withdrawn by agreement between the journal Editors and Blackwell Verlag GmbH. The article has been withdrawn for legal reasons.     

Relationships between reflectance and absorbance chlorophyll indices with RGB (Red,Green, Blue) image components in seedlings of tropical tree species at nursery stage

Methods based on RGB (Red, Green, Blue) image segmentation may emerge as a new and low-cost method for estimation the quality of tree seedlings. However, the vast number of indexes based on the use of the RGB image segmentation and the lack of references in the literature still hinder the widespread use of this technology. Thus, we conducted a study aiming to test the relationships between methods based on absorbance and reflectance, widely used for the estimation of chlorophyll contents and physiological status of trees, and ten indexes based on RGB component analysis. We used leaves of five tropical tree species, belonging to different botanical families. Leaf absorbance was measured using the handheld chlorophyll meter SPAD-502, reflectance was measured using a spectrometer and the RGB indices were obtained from digitalized images of the leaves using a flatbed scanner. Modified linear regression models including all five species were used to relate RGB indices to absorbance and reflectance indices. Data collected from leaves of seedlings of five tropical tree species indicated that digital image processing technology can be a useful and rapid nondestructive method for assessment of physiological status of tree seedlings at nursery stage. Among the RGB indexes tested in this study the R, 2R*(G???B)/(G?+?B) and 2G*(G???B)/(G?+?B) are the most promising for analysis the tropical seedlings physiological status and quality.

     

Germination and seedling growth of <Emphasis Type="Italic">Dimorphandra jorgei</Emphasis> MF Silva and <Emphasis Type="Italic">Swartzia macrostachya</Emphasis> Benth. var. <Emphasis Type="Italic">riedelii</Emphasis> Cowan

Dimorphandra jorgei MF Silva (Caesalpinaceae) and Swartzia macrostachya Benth. var. riedelii Cowan (Fabaceae) are tree species from the southern Bahian Atlantic Forest, identified for the restoration of degraded areas. The objective of this research is to study their seed germination and seedling growth to develop simple methods for seedling production in small scale nurseries. Because the species have distinct dormancy and germination characteristics, the seeds were submitted to different treatments. D. jorgei seeds were immersed in hot water, scarified and stored for 12 weeks in the laboratory environment (25°C). S. macrostachya seeds were submitted to different combinations of drying and storage in the laboratory environment or refrigerator (4°C). Seedlings were submitted to two light treatments for 3 months: partial shade (52% of full sun) and full shade (12% of full sun). In D. jorgei, the highest germination occurred for scarified seeds (87%) and for seeds stored for 12 weeks and then scarified (69%). In S. macrostachya the undried control seeds had the highest germination, followed by that of the refrigeration storage treatment, without predrying (99% and 97%, respectively). The average values for the growth parameters were greater in full shade for D. jorgei, while S. macrostachya seedlings showed greater growth rates in partial shade. Two months growth is recommended before D. jorgei seedlings are of the sufficient size and leaf number for field planting. On the other hand, a period of 4 months is recommended for S. macrostachya, due to its relatively slow growth.     

Reduced postpartum anestrus of suckled beef cows treated with microencapsulated luteinizing hormone-releasing hormone analog.

This study evaluated the effect of microencapsulated LHRH agonist (D-Trp6-LHRH) on gonadotropin release and occurrence of estrus in early postpartum beef cows. Angus cows (n = 54) were assigned randomly to two treatment groups at d 5 postpartum. Group 1 received a single i.m. injection of D-Trp6-LHRH (LHRH-A) encapsulated in poly-DL-lactide-coglycolide, calculated to release 15 micrograms of LHRH-A per day for 30 d (n = 23). Group 2 received vehicle only (control, n = 31). Blood samples (15-min intervals for 6 h) were obtained on d 5, 10, 20, 30, and 40 postpartum for evaluation of LH and FSH concentrations (n = 12 per group). Days to first postpartum estrus were reduced by treatment with LHRH-A (Group 1, 43.7 +/- 4.2 d vs Group 2, 55.9 +/- 4.7 d; P < .05). However, days to conception were similar between groups (68.9 +/- 7.9 vs 76.7 +/- 6.7 d, respectively). On the day of treatment, cows treated with LHRH-A had higher mean concentrations of LH and FSH than did controls (8.3 +/- 1.4 vs 2.0 +/- .4 ng/mL for LH and 211.0 +/- 8.6 vs 51.2 +/- 2.7 ng/mL for FSH (P < .05). There were no differences in mean concentrations of LH or FSH between treatment groups on d 10, 20, 30, and 40 postpartum. Cows given LHRH-A had more (P < .05) LH pulses on d 10 and 30 postpartum than did controls. This study demonstrated that microencapsulated D-Trp6-LHRH reduced the postpartum anestrous interval in suckled beef cows.     

Application of coupled liquid chromatography–mass spectrometry in photolysis studies of the herbicide triflusulfuron‐methyl

The photochemical fate of the herbicide triflusulfuron‐methyl in aqueous solution under UV light (λ > 290 nm) was investigated. Nine photoproducts were detected and tentatively identified by LC/MS and LC/MS/MS analysis. The main routes of degradation involve the cleavage and/or contraction of the sulfonylurea bridge with the elimination of sulfur dioxide, which increases the acidity of the reaction medium. On the basis of the results obtained a photodegradation pathway is proposed. © 2001 Society of Chemical Industry