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171.
Alexander JokiĆ Radivoje Srejić Petar A. Pfendt Joanna Zakrzewska 《Water, air, and soil pollution》1995,84(1-2):159-173
Humic acids were extracted from the bottom sediment of the three lakes (Zlatari, Vasici and Vodozahvat) that together comprise Lake ?elije a regional drinking water reservoir. The humic acids were examined by high resolution 13C and 1H solution NMR and 13C CPMAS. The aromaticity expressed as the number of benzene rings per 1000 g of humic acid is 1.8 for Zlatari, 2.3 for Vasici and 1.9 for Vodozahvat. Oxygen-substituted aromatic carbon structures in humic acids from the first two lakes (Zlatari and Vasici) are similar and resemble p-coumaryl units in lignin while those in Lake Vodozahvat more closely resemble coniferyl or sinapyl units in lignin. The aromatic rings of all three humic acids are highly substituted. Humic acids from the first two lakes have very similar carbohydrate carbon contents (19.9 and 19.5% respectively) compared to 23.3% for Vodozahvat humic acid. Zlatari and Vodozahvat humic acids have a higher alkyl chain content which indicates a greater potential for forming hydrophobic cavities. The carboxyl and aromatic OH group content of each humic acid influences their capacity for forming complexes with metal ions. 相似文献
172.
Alkylresorcinols are phenolic lipids present at levels of 0.03-0.15% in wheat and rye grains and almost 10 times higher in respective bran products. Despite numerous studies on the influence of dietary fibers on the regulation of energy metabolism, this issue still remains controversial. The objective of our current studies was to investigate whether 5-n-alk(en)ylresorcinols, natural phenolic components of high fiber human diets, may be considered as natural regulators of excessive fat accumulation. Our studies revealed that 5-n-alk(en)ylresorcinols isolated from wheat and rye bran inhibit glycerol-3-phosphate dehydrogenase, the key enzyme in triglyceride synthesis in adipocytes, specifically and effectively. Further in vitro studies showed that these compounds also prevent triglyceride accumulation in 3T3-L1 cells. The most effective compound in both systems was 5-n-heneicosylresorcinol. The results indicate that the potential to prevent triglyceride accumulation increases with the hydrophobicity of the phenolic inhibitor. 相似文献
173.
Summary High level of heterozygosity is directly related to heterosis for yield in polysomic polyploids. Modern breeding schemes in potato (2n=4×=48) involve utilization of wild or cultivated 2 x relatives that provide a source of allelic diversity, and 2n gametes that transfer diversity to the 4 x level. Different levels of allelic diversity and different modes of 2 n egg formation were considered theoretically to determine their significance for the recovery of heterotic 4 x progeny from 2××4× crosses. The support from the experimental data is provided.Decline in parental allelic diversity in 2××4× crosses or 4××4× crosses resulted in significant yield reduction. The average level of homozygosity and loss of intra-locus interactions are equally adequate to predict the trend in yield changes in 4 x potatoes derived from parents of variable allelic diversity utilizing different modes of 2 n egg formation.The differences between the modes of 2 n gamete formation increase when the genetic diversity decreases. The more genetically diverse parents the less pronounced differences between 2 n gametes. Breeding of 4 x cultivars for polygenic traits where nonadditive effects are important should be oriented towards maximizing heterozygosity in terms of allelic diversity. Utilization of 2 n gametes to generate 4 x progeny following 2×–× or 2×–2× crosses upgrades the level of heterozygosity depending on diversity present in parents. 相似文献
174.
175.
Joanna Szlendak Christine Adler Jakob Scherzer Anna Niwinska Ewa Kautz Ricardo Faundez 《Reproduction in domestic animals》2020,55(6):691-700
The aim of the present study was to evaluate the effect of sperm selection by single-layer centrifugation (SLC) performed before freezing on sperm quality after thawing of Fleckvieh bull semen. Ejaculates from 22 bulls were collected by artificial vagina and divided into two aliquots. One aliquot (control sample) was diluted with Steridyl® and frozen over nitrogen vapour in a Digitcool freezer (IMV Technologies). Sperm from the second aliquot (SLC sample) was selected using the SLC technique with Bovicoll colloid and then frozen over nitrogen vapour in a Digitcool freezer. After thawing, both samples (control and SLC) were evaluated by computer-aided sperm analysis (CASA; SCA 6.4 System; Microptic S.L) for sperm motility parameters. Integrity of the plasma membrane (viability), high mitochondrial membrane potential (HMMP) and acrosome integrity were assessed using a Guava® easyCyte flow cytometer (IMV Technologies). Morphological examination of spermatozoa was performed by Differential Interference Contrast microscopy (Leica DMi8). Morphological examination of live, immobilized spermatozoa was analysed under high magnification (≥6,600×). After thawing, the mean sperm viability of the control sample was 51.57%, compared to 40.37% for the SLC sample (p < .01). HMMP was higher (p < .01) in the control sample (40.37% versus 28.96%), and the mean of live spermatozoa with damaged acrosome was significantly higher (p < .03) in the SLC sample (1.63% versus 1.95%). The mean percentage of motile spermatozoa was 80.17% in the control sample, compared to 75.14% in the SLC sample (p < .0195), and rapid subpopulation reduced from 20.08% to 8.99% (p < .0001) after SLC. Percentage of hyperactivated sperm decreased from 12.23% to 4.28% (p < .0001) after SLC. Given the overall results, the sperm quality of thawed Fleckvieh bull semen was not improved when sperm were selected by SLC before freezing. 相似文献
176.
Marina Monteiro Netto Mario Felipe Alvarez Balaro Isabel Oliveira Cosentino Caroline Gomes do Espírito Santo Rodrigo Vasconcelos de Oliveira Joanna Maria Gonçalves Souza-Fabjan Felipe Zandonadi Brandão Jeferson Ferreira Fonseca 《Reproduction in domestic animals》2020,55(8):965-973
This study assessed the efficiency of synchronous oestrous induction by light programme followed by two doses of cloprostenol in acyclic Saanen goats of different parity orders. Primiparous (n = 22) and multiparous (n = 33) goats were subjected to 16 hr of light and 8 hr of darkness for 60 days (D0-D60), starting 10 days after the winter solstice. All goats received 120 µg cloprostenol doses on D130 (morning) and D141.5 (afternoon) (11.5 days apart). Oestrus behaviour, ovarian follicular dynamics and serum progesterone (P4) analyses were recorded from D0 to D174 at different intervals. Animals in oestrus after D141.5 were randomly assigned into two groups: assisted natural mating (NM) or artificial insemination (AI; 10–24 hr after oestrus onset with frozen-thawed semen). From D57 to D120, 89.0% of goats presented large follicles (5–8 mm) and P4 concentrations were subluteal from D0 to D120. More multiparous compared to primiparous goats (54.5%, 18/33 vs. 18.2%, 4/22) exhibited oestrus after both injections. More primiparous compared to multiparous goats (54.5%, 12/22 vs. 12.1%, 4/33) did not exhibit oestrus after any injection. A total of 35 goats (64%) were in oestrus after the second prostaglandin injection and were subjected to NM or AI. The conception rate was similar among primiparous (70.0%, 7/10) and multiparous (68.0%, 17/25) goats but the pregnancy rate differed, being 31.8% (7/22) and 51.5% (17/33), respectively. No interaction was found between parity order and P4 concentrations in does that became pregnant or not. Thus, the association between light programme (60 days, starting at the beginning of winter) and two cloprostenol administrations 11.5 days apart (starting 70 days after the end of the light treatment) resulted in sufficient synchronous oestrous response in multiparous acyclic Saanen goats to reach satisfactory fertility levels after both NM and AI. 相似文献
177.
Agnieszka Nowak Joanna Kochan Ewa Świętek Barbara Kij Sylwia Prochowska Wojciech Witarski Monika Bugno-Poniewierska Wojciech Niżański 《Reproduction in domestic animals》2020,55(8):992-997
The aim of this study was to evaluate the applicability of the Cryotech technique for the vitrification of domestic cat (Felis catus) oocytes, as a model for other feline species threatened with extinction. This technique, in which oocytes are stored in a minimal volume of medium, is already widely used in human assisted reproductive technology. In the first part of this study, a viability test (EtBr/FDA) was used to evaluate the toxicity of the vitrification media (solutions). After IVM, oocytes were placed in vitrification and warming solutions according to the manufacturer's procedure, with or without exposure to liquid nitrogen. The solutions and the vitrification procedure each caused a reduction in oocyte viability, with survival rates of 71.4% in oocytes exposed to the Cryotech media (without cooling in liquid nitrogen), and 62% in oocytes that were vitrified. In the second part of the experiment, parthenogenetic activation was used to evaluate the developmental potential of oocytes previously vitrified using the Cryotech method. After warming, the oocytes were activated using a combination of 0.7 µM ionomycin in TCM 199 medium (5 min) followed by 2 mM 6-DMAP in TCM 199 supplemented with 10% FBS (3 hr), then cultured and evaluated every 24 hr for parthenogenetic cleavage. In the experimental group, 23/50 (46%) cleaved embryos were obtained. Domestic cat oocytes, vitrified by the Cryotech method, are characterized by high survival rates. However, it is necessary to improve the technique to increase the developmental competence of embryos obtained from vitrified oocytes. 相似文献
178.
179.
Dariusz Piwczyski Beata Sitkowska Magdalena Kolenda Marcin Brzozowski Joanna Aerts Pamela M. Schork 《Animal Science Journal》2020,91(1)
The purpose of this paper was to utilize the decision trees technique to determine the factors responsible for high monthly milk yield in Polish Holstein‐Friesian cows from 27 herds equipped with milking robots. The applied statistical method—the decision tree technique—showed that the most important factors responsible for monthly milk yield of dairy cows using robots were, in descending order of importance: milking frequency, lactation number, month of milking, and type of lying stall. At the same time, it has been ascertained that the highest monthly milk yield (47.24 kg) can be expected from multiparous cows kept in barns with a deep bedding that were milked more frequently than three times per day. On the other hand, the lowest milk production (13.56 kg) was observed among dairy cows milked less frequently than two times a day, with an average number of milked quarters lower than 3.97. The application of the decision trees technique allows a breeder to select appropriate levels of environmental factors and parameters that will help to ensure maximized milk production. 相似文献
180.
Murray D. Wiegand Cheryl L. Kitchen Joy M. Hataley 《Fish physiology and biochemistry》1991,9(3):199-213
In five separate experiments, eggs from a single female goldfish were fertilized at 20°C. They were incubated at 22°C for 6 hours, after which some of the eggs were transferred to 13°C. When a defined post-hatch developmental stage was reached, lipid extracts were prepared from larvae, both with yolk sacs intact and after removal of the yolk sac by dissection. Other larvae were sampled at yolk exhaustion. Gas chromatographic analysis of fatty acid profiles revealed that larvae incorporated 16:0, 18:0, 20:4 (n–6) and 22:6 (n–3) into their tissues in proportions higher than those present in the eggs from which they were derived. At 22°C, these trends were particularly apparent at yolk exhaustion. At 13°C, proportions of polyunsaturated fatty acids in the bodies of newly hatched larvae were higher than those in the 22°C larval bodies. Monounsaturated fatty acids were preferentially depleted during development, especially in larvae from high quality eggs. No dependence of egg quality, as assessed by larval viability at 22°C, on total egg lipid mass or fatty acid composition was found. Larvae from the lowest quality eggs showed a reduced preference for incorporation of (n–3) polyunsaturated fatty acids into their tissues. 相似文献