Showing papers on "Incubation published in 2001"
TL;DR: It is concluded that more independent control as well as more control of the variability of the classical physical conditions in the incubator are required in order to improve hatchability and chick quality.
Abstract: The quality of the day-old broiler chick is foremost in the minds of many poultry managers. From fertilised ovum to the placement at the broiler farm, some factors such as the characteristics of the incubating eggs, the egg holding conditions, the incubation conditions and the conditions that exist between hatching and placement at the farm and their interactions may affect chick quality. It may be questioned if maximal hatchability is the best indicator for chick quality and/or post-hatching viability, even if optimal hatchability is considered a prerequisite for successful incubation. The environmental conditions during incubation (e.g. the temperature, humidity and ventilation rate (carbon dioxide concentration)) are not set independently from each other, although each may have its own optimum for hatchability and chick quality. These optima for each incubation factor may alter differentially according to the characteristics of the incubating egg. It is concluded that more independent control as well as more control of the variability of the classical physical conditions in the incubator are required in order to improve hatchability and chick quality.
180 citations
TL;DR: Hatching success was significantly correlated with incubation temperature, with nests experiencing very high temperatures exhibiting low hatching success, and incubation duration was found to be significantly correlated to both the mean temperature of nests throughout the incubation period and during the middle third of incubation.
132 citations
TL;DR: The present results clearly indicate that BPA is metabolically activated in terms of estrogenicity under the conditions existing only with combined rat liver microsomes and cytosol.
132 citations
TL;DR: In ovo administration of AA may increase AA concentrations in chicken embryos and other egg contents in the presence or absence of in ovo AA administration.
116 citations
TL;DR: Increased absence from the nest site in individual glaucous gulls with high blood concentrations of OC suggests effects on reproductive behaviour, and it is speculated that endocrine disruption or neurological effects might be involved, leading to increased energetic costs during incubation and reduced reproductive output.
Abstract: Summary 1. Although experimental studies show that organochlorines (OC) can affect bird behaviour, field assessments are invariably confounded by ecological differences between contaminated and uncontaminated sites. The behaviour of individual birds in the field has rarely been related to the contaminant burden. 2. We examined individual patterns of incubation and nest-site attentiveness in relation to OC burden, measured as polychlorinated biphenyl (PCB) concentration in the blood, of 27 glaucous gulls Larus hyperboreus in two breeding areas at Bear Island, in the north-eastern Atlantic. 3. Blood PCB concentrations ranged from 52 ng g - 1 to 1079 ng g - 1 (wet weight). There were significant differences between the two breeding areas, and females had signi ficantly lower concentrations than males. 4. Gull behaviour differed significantly between breeding areas and sexes independently of PCB. Females incubated more than males (54% vs. 46%) but spent more time away from the nest site than males, both overall (23% vs. 12%) and when not incubating (50% vs. 21%). They were also absent for longer periods (4·5 vs. 2·8 h). Moreover, length of incubation bouts (6·4 vs. 4·4 h), the amount of time absent from the nest site when not incubating (51% vs. 25%) and length of absences (5·6 vs. 1·8 h) differed between breeding areas, probably due to different feeding specializations. 5. After controlling for these area and sex effects, the proportion of time absent from the nest site when not incubating, and the number of absences, were both significantly related to blood concentration of PCB. 6. Increased absence from the nest site in individual glaucous gulls with high blood concentrations of OC suggests effects on reproductive behaviour. We speculate that endocrine disruption or neurological effects might be involved, leading to increased energetic costs during incubation and reduced reproductive output.
114 citations
TL;DR: Results indicate that the eggs that incubate best are produced by the hens of 40 to 42 wk of age, and regulation of relative humidity during incubation to achieve optimum weight loss may take into account only the eggs characteristics.
Abstract: SUMMARY The age of broiler breeders is an important parameter to be taken into account by the hatchery manager. Eggs produced by young or old breeders do not hatch as well as the eggs from the breeders of 40 to 42 wks of age. Field reports indicate that there are quadratic relationships between age of breeders and absolute egg weight loss during incubation, age of breeders and hatchability, and age of breeders and embryonic mortality. There is a trend of optimum relative egg weight loss on Day 18 of incubation for the highest hatchability. These results indicate that the eggs that incubate best are produced by the hens of 40 to 42 wk of age. It is suggested that the egg characteristics and the age of breeders have to be taken into account during incubation in order to design optimal incubation conditions and to improve hatchability. However, because the relative egg weight loss is not linked to the age of breeders, regulation of relative humidity during incubation to achieve optimum weight loss may take into account only the eggs characteristics.
104 citations
TL;DR: Results of this study suggest TNF‐α may induce caspase‐3 activation but not calpain activation in septo‐hippocampal cultures and that this activation of casp enzyme‐3 at least partially contributes to T NF‐α‐induced apoptosis.
Abstract: Primary septo-hippocampal cell cultures were incubated in varying concentrations of tumor necrosis factor (TNF-α; 0.3–500 ng/ml) to examine proteolysis of the cytoskeletal protein α-spectrin (240 kDa) to a signature 145 kDa fragment by calpain and to the apoptotic-linked 120-kDa fragment by caspase-3. The effects of TNF-α incubation on morphology and cell viability were assayed by fluorescein diacetate-propidium iodide (FDA-PI) staining, assays of lactate dehydrogenase (LDH) release, nuclear chromatin alterations (Hoechst 33258), and internucleosomal DNA fragmentation. Incubation with varying concentrations of TNF-α produced rapid increases in LDH release and nuclear PI uptake that were sustained over 48 hr. Incubation with 30 ng/ml TNF-α yielded maximal, 3-fold, increase in LDH release and was associated with caspase-specific 120-kDa fragment but not calpain-specific 145-kDa fragment as early as 3.5 hr after injury. Incubation with the pan-caspase inhibitor, carbobenzosy- Asp-CH2-OC (O)-2-6-dichlorobenzene (Z-D-DCB, 50-140 μM) significantly reduced LDH release produced by TNF-α. Apoptotic-associated oligonucleosomal-sized DNA fragmentation on agarose gels was detected from 6 to 72 hr after exposure to TNF-α. Histochemical changes included chromatin condensation, nuclear fragmentation, and formation of apoptotic bodies. Results of this study suggest TNF-α may induce caspase-3 activation but not calpain activation in septo-hippocampal cultures and that this activation of caspase-3 at least partially contributes to TNF-α-induced apoptosis. J. Neurosci. Res. 64:121–131, 2001. © 2001 Wiley-Liss, Inc.
102 citations
TL;DR: Co-incubation of spermatozoa with dead EB abolished the chlamydia-mediated response, indicating that a detrimental effect on sperm function by some serovars may be an as yet unrecognized component of infertility problems.
Abstract: The aim of this work was to investigate the effect of elementary bodies (EB) of Chlamydia trachomatis serovars E and LGV on sperm motility, viability and acrosomal status. Highly motile preparations of spermatozoa from normozoospermic patients were co-incubated for 6 h with 0.54x10(6) EB per ml. At 1, 3 and 6 h of incubation, sperm motility was determined by computer-assisted semen analysis (CASA) and the proportion of dead cells determined by the hypo-osmotic swelling (HOS) test. Acrosomal status was also examined using a standard monoclonal antibody assay. In the absence of EB, the percentage of motile spermatozoa remained >69% over the 6h incubation and the proportion of dead spermatozoa at <12%. However, during the incubation with EB of serovar E there was a significant decline in the percentage of motile spermatozoa (P < 0.05), and a corresponding increase in the proportion of dead spermatozoa (P < 0.05) at all time-points. However, following incubation with serovar LGV, only the percentage of dead spermatozoa after 6 h incubation was significantly different from the control (P < 0.05). The amount of acrosome-reacted spermatozoa remained unchanged (<16%) in all incubations at all time-points. Dose-response experiments indicated that increasing the concentration of EB to 2.5x10(6) per ml did not significantly alter the results. Furthermore, co-incubation of spermatozoa with dead EB (killed by heat treatment) abolished the chlamydia-mediated response, indicating that the effect is a result of the live organism and not soluble components or membrane elements. These data suggest that a detrimental effect on sperm function by some serovars may be an as yet unrecognized component of infertility problems.
101 citations
TL;DR: Motility may be a relevant physiological marker for DNA-intact sperm after exposure of spermatozoa to H(2)O( 2) and alpha irradiation and when only motile spermatoza from irradiated samples were analysed, only 0.5% were TUNEL positive.
Abstract: BACKGROUND: In this study we present the physiological changes observed in ejaculated spermatozoa of normospermic men after exposure to hydrogen peroxide (H2O2 )o rγ irradiation. METHODS: Motility changes as well as membrane and DNA-damage were determined in spermatozoa after incubation with 25 µmol/l of H2O2 during increasing intervals of time (0–60 min and after 24 h) or after irradiation of cells using α rays. Annexin V-binding in combination with propidium iodide was used for the assessment of membrane changes after each incubation time. TdT-mediated-dUTP nick-end labelling (TUNEL) was used to evaluate DNA damage. RESULTS: After 1 h incubation of the spermatozoa with H2O2, almost all cells were positive for Annexin-V, while no significantly increase in TUNEL positivity was observed. TUNEL results were significantly higher 24 h after incubation with H2O2 (10–16.3%, P 0.03). In the control group (cumulus cells), an increase in the percentage of TUNEL positive cells was observed after 15 min of incubation with H2O2 and showed a five-fold increase after 24 h (from 8.1– 72.1%, P < 0.001). TUNEL positive cells after α irradiation increased with the doses and post-irradiation time (from 10.8–47.2%). Interestingly, when only motile spermatozoa from irradiated samples were analysed, only 0.5% were TUNEL positive. CONCLUSION: Motility may be a relevant physiological marker for DNA-intact sperm after exposure of spermatozoa to H2O2 and α irradiation.
93 citations
Journal Article•
TL;DR: The cellular metabolism of these drugs and their actions in a human multiple myeloma cell line are identified and demonstrate that the cytotoxic metabolite of 8-Cl-Ado and 8- Cl-cAMP is 8-cl-ATP.
Abstract: Previous work with 8-chloro-cAMP (8-Cl-cAMP) has raised questions as to whether it works as a cAMP analogue or as a nucleoside analogue after its conversion to 8-chloro-adenosine (8-Cl-Ado). Although degradation of 8-Cl-cAMP to 8-Cl-Ado in culture medium or plasma has been shown, cellular pharmacology data are missing. The purpose of the present study was to identify the cellular metabolism of these drugs and their actions in a human multiple myeloma cell line. The cells were incubated with either 8-Cl-Ado or 8-Cl-cAMP to follow the cellular metabolism of these agents. Both 8-Cl-cAMP and 8-Cl-Ado incubation resulted in the accumulation of 8-Cl-Ado mono-, di-, and tri-phosphate (8-Cl-ATP), however, the triphosphate was the major cytotoxic metabolite. Accumulation of 8-Cl-ATP was dependent on both the exogenous concentration of 8-Cl-Ado and incubation time. At the 10 microM level of 8-Cl-Ado, >400 microM 8-Cl-ATP accumulated in multiple myeloma cells after continuous incubation for 12 h. Similar incubation with 8-Cl-cAMP also resulted in accumulation of 8-Cl-ATP in the cells, albeit at a lower level. The formation of 8-Cl-ATP from 8-Cl-cAMP was inhibited by >80% in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine in the medium, suggesting extracellular conversion of 8-Cl-cAMP to 8-Cl-Ado. Cells lacking Ado kinase did not accumulate 8-Cl-ATP, either from 8-Cl-Ado or 8-Cl-cAMP, and were resistant to these agents. There was also a decline in the endogenous level of the cellular ATP pool parallel to the accumulation of 8-C1-ATP. The elimination of 8-Cl-ATP was biphasic and slow from the cells. The accumulation of 8-Cl-ATP and a decline in the ATP pool inhibited RNA synthesis but did not affect DNA synthesis for up to 12 h of incubation. Taken together, these data demonstrate that the cytotoxic metabolite of 8-Cl-Ado and 8-Cl-cAMP is 8-Cl-ATP. Hence, 8-Cl-cAMP serves as a prodrug and is converted to 8-Cl-Ado in medium with subsequent phosphorylation to accumulate as 8-Cl-ATP in cells. At the cellular level, 8-Cl-ATP is associated with a decrease in the endogenous ATP pool; at the nuclear level, it inhibits RNA synthesis.
90 citations
TL;DR: The effect of soil treatment with pesticides on arylsulphataseactivity fluctuated between promotion and inhibition, but inhibition was predominant, suggesting a direct role of alkaline soil pH in increasing resistance of alkali phosphatase to pesticides.
Abstract: The effect of soil treatment with brominal (a herbicide) and theinsecticide selecron (the equivalent field rates and five-fold) on population counts of bacteria, actinomycetes and celluloyticfungi in soil was tested throughout 10 weeks incubation at28 °C. Also, tested their effect on four soil enzymes:cellulase, acid phosphatase, alkaline phosphatase andarylsulphatase. Bacterial and actinomycetes populations in soiltreated with the two pesticides were promoted at fieldapplication rates and inhibited at higher levels. The twopesticides significantly decreased the total number ofcellulolytic fungi and most fungal species after most incubationperiods either by one or the two used levels but the effect ofselecron was more pronounced.Cellulase activity in soil treated with brominal and selecronwas inhibited after most incubation periods. The effect of soiltreatment with the two pesticides on acid phosphatase waspromotive at field application rates after some incubationperiods but the enzyme activity was delayed at the higherapplication doses. Alkaline phosphatase activity in treated soilwas accelerated with both pesticides even at the higherapplication rates, suggesting a direct role of alkaline soil pHin increasing resistance of alkaline phosphatase to pesticides.The effect of soil treatment with pesticides on arylsulphataseactivity fluctuated between promotion and inhibition, butinhibition was predominant.
TL;DR: Data do not support the generalization that water availability during embryogenesis is more important than temperature in determining the phenotypes of hatchling reptiles, and suggest that hatchling lizards react less plastically to variation in moisture levels than they do to thermal conditions.
Abstract: Recent studies have shown that incubation temperatures can profoundly affect the phenotypes of hatchling lizards, but the effects of hydric incubation environments remain controversial. We examined incubation-induced phenotypic variation in Bassiana duperreyi (Gray, 1938; Sauria: Scincidae), an oviparous montane lizard from south-eastern Australia. We incubated eggs from this species in four laboratory treatments, mimicking cool and moist, cool and dry, warm and moist, and warm and dry natural nest-sites, and assessed several morphological and behavioural traits of lizards after hatching. Incubation temperature influenced a lizard's hatching success, incubation period, tail length and antipredator behaviour, whereas variation in hydric conditions did not engender significant phenotypic variation for most traits. However, moisture affected incubation period slightly differently in males and females, and for a given snout-vent length moisture interacted weakly with temperature to affect lizard body mass. Although incubation conditions can substantially affect phenotypic variation among hatchling lizards, the absence of strong hydric effects suggests that hatchling lizards react less plastically to variation in moisture levels than they do to thermal conditions. Thus, our data do not support the generalization that water availability during embryogenesis is more important than temperature in determining the phenotypes of hatchling reptiles.
TL;DR: Sex differences in phenotypic responses of hatchling snakes support a major assumption of the Charnov-Bull hypothesis for the evolution of temperature-dependent sex determination.
Abstract: 1. The physical conditions experienced by reptile embryos inside natural nests can influence the size, shape and behaviour of the resultant hatchlings. Although most reptiles are tropical, the effects of incubation temperatures on offspring phenotypes have received little attention in tropical species. 2. The consequences of differences in thermal variance during incubation on offspring were studied in a tropical natricine snake (the Keelback Tropidonophis mairii), which lays eggs in soil cracks of varying depths. Some 253 eggs from 19 clutches were incubated under two thermal regimes with identical mean temperatures (25.6 degreesC), but temperatures in the 'variable' treatment fluctuated more (21.8-29.6 degreesC) than those in the 'constant' temperature treatment (25.2-26.5 degreesC). These thermal regimes were similar to those of shallow (20 cm deep) and deep (40 cm deep) soil cracks, respectively, and represent thermal conditions inside natural nests and potential nest sites. 3. Incubation temperatures affected body size, shape and antipredator behaviour of hatchling snakes. Snakes from constant temperature incubation were longer and thinner than snakes from high variance incubation. Clutch effects influenced all offspring traits, with significant interactions between clutch of origin and incubation treatment for body size, but not swimming speed or behaviour. 4. There was a significant interaction between incubation treatment and offspring sex on neonate swimming speed. Incubation under cycling thermal regimes significantly increased swimming speeds of females, but had little effect on males. Such sex differences in phenotypic responses of hatchling snakes support a major assumption of the Charnov-Bull hypothesis for the evolution of temperature-dependent sex determination.
TL;DR: The major alteration observed in sperm function during the prolonged in vitro incubation was a reduction in the number of motile spermatozoa, together with an impairment in the quality of sperm movement.
Abstract: Summary. Prolonged incubation of human spermatozoa can have deleterious effects on sperm function. The aim of this paper was to describe the effects of a prolonged in vitro incubation, under similar conditions to those employed in human assisted reproduction, on various sperm functional parameters, and to investigate the effect of an antioxidant (catalase) on this system. Freshly collected ejaculates from 20 healthy donors were studied. Samples were divided into two aliquots: the first was incubated with Ham's F10 containing 3.5% HAS, and the second was incubated in the same medium plus catalase (100 units ml−1). All experiments were carried out with spermatozoa isolated using the swim-up technique. Spermatozoa recovered from the supernatant after 1 h (T1) of incubation in 5% CO2 in air at 37 °C, and after 5 h (T6), 23 h (T24) and 47 h (T48), were evaluated for concentration, motion parameters including hyperactivation (computer-assisted analysis), viability, ATP concentration, reactive oxygen species (ROS) generation, DNA integrity (acridine orange), and acrosome reaction (AR). The major alteration observed in sperm function during the prolonged in vitro incubation was a reduction in the number of motile spermatozoa, together with an impairment in the quality of sperm movement. ROS levels increased with the incubation time. No substantial modifications of sperm viability, chromatin condensation and AR inducibility were observed. The addition of catalase to the medium, while keeping ROS values within baseline levels, did not prevent the loss of motility or the corresponding increase in ATP.
TL;DR: Natator depressus eggs seem to be laid with sufficient water reserves for successful embryonic growth and development, which would make them independent of supplementary water from the environment.
Abstract: During the Australian summers of 1996/1997 and 1997/1998, the embryonic development of Natator depressus was investigated in the laboratory. Eggs were incubated under different thermal and hydric conditions on vermiculite substrates. The thermal environment between 26 and 32 C significantly influenced the water exchange of eggs, incubation duration, nutrient mobilization of embryos, and the size, tissue hydration, and energy reserves of hatchlings. Hatchlings produced at 26 C and 29 C were larger but had lower energy reserves than those produced at 32 C. The influence of the hydric environment depended greatly on the range of substrate water potentials used in experiments. Nutrient mobilization of embryos and the size and energy reserves of hatchlings were dependent on total egg water exchange over the range of 2% gain to 29% loss (at approximately −180 to −3500 kPa incubation substrates) of initial egg mass but independent within the narrower range of 6% gain to 19% loss (at approximately −200 t...
TL;DR: Evidence is added showing that embryonic development in reptiles with pliable-shelled eggs is relatively insensitive to variation in hydric environments during incubation.
Abstract: We examined the effects of thermal and hydric environments on hatching success, the embryonic use of energy and hatchling traits in a colubrid snake, Elaphe carinata. The eggs were incubated at four temperatures ranging from 24 to 32 degrees C on substrates with water potentials of 0 and -220 kPa using a 4x2 factorial design. Both thermal and hydric environments affected the water exchange between eggs and their surroundings. Eggs incubated in wetter substrates gained mass throughout the course of incubation, whereas eggs in drier substrates gained mass during the first half of incubation and lost mass thereafter. Hatching success was noticeably higher at 26 and 30 degrees C than at 24 and 32 degrees C, but among treatments, differences in hatching success were not significant. Temperature significantly affected the duration of incubation and most hatchling traits examined. Deformed hatchlings were found in all temperature treatments, with more deformities observed at 32 degrees C. Hatchlings from eggs incubated at different temperatures differed in wet body mass, but the differences stemmed mainly from variation in water contents. Embryos at different temperatures completed development at nearly the same expenditure of energy and catabolized nearly the same amount of lipids, but hatchlings from different temperatures differed in the development condition of carcass at hatching. Hatchlings from eggs incubated at 26 degrees C were larger in SVL than those from other higher or lower incubation temperatures, characteristically having larger carcasses; hatchlings from 32 degrees C eggs were smaller in SVL and had smaller carcasses but larger residual yolks than those from lower incubation temperatures. Hatchlings from eggs incubated at 24 degrees C were shorter in tail length but greater in size (SVL)-specific body wet mass than those from higher incubation temperatures. Within the range from -220 to 0 kPa, the substrate water potential did not affect hatching success, the embryonic use of energy and all hatchling traits examined, and the effects of temperature were independent of the effects of substrate water potential. Therefore, our data add evidence showing that embryonic development in reptiles with pliable-shelled eggs is relatively insensitive to variation in hydric environments during incubation.
TL;DR: The results from both experiments suggest that intersexual advertisement, rather than territorial aggression, may be dependent on high T levels in this species.
TL;DR: Temperature influenced the developmental rate, survival and early growth of eggs and embryos of spotted wolffish, Anarhichas minor (Olafsen), an interesting candidate for cold water cultivation and the transformation of yolk to body mass during incubation appeared to be most efficient at 4 °C.
Abstract: Temperature influenced the developmental rate, survival and early growth of eggs and embryos of spotted wolffish, Anarhichas minor (Olafsen), an interesting candidate for cold water cultivation. The total incubation period decreased from 220 days at 4 °C (880 daydegrees), to 177 days at 6 °C (1062 daydegrees) and 150 days at 8 °C (1200 daydegrees) in these experiments. The proportion of normal embryos and survival of eggs until hatching were highest when the eggs were incubated at 6 °C. During the incubation period, the embryo and yolk sac size at 280 daydegrees was not significantly different but at 850 daydegrees the embryo size was inversely related to temperature and the remaining yolk sac size positively correlated with the incubation temperature. The transformation of yolk to body mass during incubation appeared to be most efficient at 4 °C, and the embryos hatched with a larger visible yolk sac at 6 and 8 °C. The largest larvae (wet-weight) hatched from the largest eggs and the egg groups incubated at the lowest temperature (4 °C). There was no effect of temperature on meristic characters. During 6 weeks post-hatching, all larvae from the three temperature groups were fed formulated dry feed in excess at 8 °C in low water-level raceway systems. During startfeeding, the larvae from eggs incubated at the lowest temperature (4 °C) showed the highest growth rates (SGR). Best survival of larvae was noted among batches incubated at 6 °C.
TL;DR: There were no differences between the slopes of the temperature adaptation indices over time for peat samples incubated at 55°C 3 or 11 days before incubation at 25°C, indicating that different levels of bacterial activity did not affect the temperature-driven adaptation of the bacterial community.
Abstract: The temperature-driven adaptation of the bacterial community in peat was studied, by altering temperature to simulate self-heating and a subsequent return to mesophilic conditions. The technique used consisted of extracting the bacterial community from peat using homogenization-centrifugation and measuring the rates of thymidine (TdR) or leucine (Leu) incorporation by the extracted bacterial community at different temperatures. Increasing the peat incubation temperature from 25°C to 35, 45, or 55°C resulted in a selection of bacterial communities whose optimum temperatures for activity correlated to the peat incubation temperatures. Although TdR and Leu incorporations were significantly correlated, the Leu/TdR incorporation ratios were affected by temperature. Higher Leu/TdR incorporation ratios were found at higher temperatures of incubation of the extracted bacterial community. Higher Leu/TdR incorporation ratios were also found for bacteria in peat samples incubated at higher temperatures. The reappearance of the mesophilic community and disappearance of the thermophilic community when the incubation temperature of the peat was shifted down were monitored by measuring TdR incorporation at 55°C (thermophilic activity) and 25°C (mesophilic activity). Shifting the peat incubation temperature from 55 to 25°C resulted in a recovery of the mesophilic activity, with a subsequent disappearance of the thermophilic activity. The availability of substrate for bacterial growth varied over time and among different peat samples. To avoid confounding effects of substrate availability, a temperature adaptation index was calculated. This index consisted of the log10 ratio of TdR incorporation at 55 and 25°C. The temperature index decreased linearly with time, indicating that no thermophilic activity would be detected by the TdR technique 1 month after the temperature downshift. There were no differences between the slopes of the temperature adaptation indices over time for peat samples incubated at 55°C 3 or 11 days before incubation at 25°C. Thus, different levels of bacterial activity did not affect the temperature-driven adaptation of the bacterial community.
TL;DR: I(n) has a role in promoting neural differentiation and growth, but exogenous insulin promoted neural differentiated and growth beyond I(n).
TL;DR: The effect of spawning on European catfish females with an average body weight of 5.6 kg and 11.2 kg was investigated, with carp pituitary and Ovopel being used as ovulation stimulators and induced ovulation in a higher percentage of females of both smaller and larger body weight.
Abstract: The effect of spawning on European catfish females with an average body weight of 5.6 kg and 11.2 kg was investigated, with carp pituitary and Ovopel being used as ovulation stimulators. Ovopel induced ovulation in a higher percentage of females of both smaller and larger body weight. The applied ovulation stimulators did not significantly affect the weight of the obtained eggs. On the other hand, the effect of the stimulators was highly significant (P≤ 0.01) with respect to the percentage of live embryos after 24-, 48- and 56-h incubation. The fish of greater body weight yielded eggs of a significantly (P≤ 0.05) greater weight, although of poorer quality. The interaction between the ovulation stimulator and female body weight was statistically significant (P≤ 0.05) for the weight of the obtained eggs and highly significant (P≤ 0.01) for the percentage of live embryos after 48-h incubation. For the percentage of live embryos after 24- and 56-h incubation, the statistical significance (P≤ 0.05) of this interaction was determined. In the case of females of smaller body weight, a statistically significant (P≤ 0.05) phenotypic correlation was found between the percentage of live embryos after 24-h incubation and that after 48-h incubation, and also between the percentage of live embryos after 24- and 56-h incubation.
TL;DR: Results suggest that supplemental Cr may alter systemic lipid metabolism and in vitro fermentation altered VFA production with graded concentration of Cr and was not toxic to ruminal microorganisms at concentrations up to 25.6 mg/kg.
TL;DR: Progesterone inhibits the proliferation and elicites apoptosis of SNU‐840 cells, Also, it up‐regulates the p53 mRNA transiently.
Abstract: Progesterone has been used as an ingredient of anticancer drug for patients with ovarian carcinoma. However, the mechanism of anticancer effects by progesterone has not been understood. In this study, the effects of progesterone on ovarian cancer cells, SNU-840, were investigated. After the incubation with progesterone, the viability of the cells was evaluated by MTT assay. As a result, 45% of the cells were viable after 48 h of incubation with 100 microM progesterone. In addition, [(3)H]thymidine incorporation assay showed that the proliferation of the cells was completely inhibited by progesterone after 48 h of incubation at 100 microM concentration. Colorimetric TUNEL assay revealed the fragmentation of the chromosomal DNA, suggesting that the process of the cell death was apoptosis. The level of the p53 mRNA was determined by northern blotting assay, since many apoptosis processes are mediated by up-regulation of the p53 expression. The level of the p53 mRNA reached its maximum at 12 h and decreased after 24 h of incubation with progesterone. In conclusion, progesterone inhibits the proliferation and elicits apoptosis of SNU-840 cells. Also, it up-regulates the p53 mRNA transiently.
TL;DR: In this article, methylmercury (MeHg) methylation was studied in water, sediment and Eichhornia crassipes roots of a freshwater lake, in Rio de Janeiro(Brazil).
Abstract: Mercury (Hg) methylation was studied in water,sediment and Eichhornia crassipesroots of a freshwater lake, in Rio de Janeiro(Brazil). Samples were incubated with203HgCl2 and the Me203Hg producedwas measured by liquid scintillation.Methylmercury (MeHg) production was <10-3% in water, low in sediment (up to5.8%) and high in E. crassipesroots (21–27%). Higher MeHg formation wasfound in aerobic conditions for the roots and inanaerobic conditions for the sediment.Methylation increased with incubation time, upto 5 days. A 3-day incubation period was used inthe majority of the assays, to avoid large scalephysico-chemical changes inside the incubationflasks. Methylation was not detected inheat-sterilized root samples. Sodium sulphatestimulated Hg methylation while sodium molybdateinhibited the process in samples incubated for3, 6, 12, 24, 48 and 72 hr. This suggeststhat sulphidogenic bacteria are responsible forthe methylation process. Experiments with rootsstored at 5 and 25 °C fordifferent periods before incubation, indicatethat methylation is modified by storage time and temperature.
TL;DR: Larvae reared during the first 3 months of exogenous feeding in a common environment at constant 21° C, revealed maximum survival for an incubation temperature of 15° C (43% of burrowed larvae) decreasing strongly at 19°C (16%) and 23° C and one suvivor among 240 larvae.
Abstract: This study assesses the influence of thermal regime on the development, survival rates and early growth of embryos of sea lamprey Petromyzon marinus incubated at five constant temperatures (7, 11, 15, 19 and 23° C). The time from fertilization to 50% hatching and from hatching to 50% burrowing were inversely related to incubation temperature. All the embryos incubated at 7° C died at very early stages, while those maintained at 11° C did not attain the burrowing stage. Survival from fertilization to hatching was 61, 89, 91 and 89% at 11, 15, 19 and 23° C, decreasing to 58, 70 and 70% from hatching to burrowing at 15, 19 and 23° C, respectively. Larvae reared during the first 3 months of exogenous feeding in a common environment at constant 21° C, revealed maximum survival for an incubation temperature of 15° C (43% of burrowed larvae) decreasing strongly at 19° C (16%) and 23° C (one suvivor among 240 larvae). Body length at the burrowing stage was maximum for embryos incubated at 19° C, but body mass increased in the interval 15–23° C. Mean incubation temperatures experienced by 117 broods during the embryonic development in the source river were estimated in 15·3±2·30° C and 16·7±1·76° C (mean±1 s.d.) for the periods fertilization-to-hatching and hatching-to burrowing, respectively.
TL;DR: Both developmental success and hatching success of laboratory-incubated eggs were dependent to a greater extent on temperature than on moisture, with an increase in mortality as sand temperature increased.
Abstract: We investigated the effect of sand moisture content and sand temperature on developmental success and the mobilization of calcium during development using laboratory incubated eggs (n=251) collected from leatherbacks nesting at Parque Nacional Marino Las Baulas, Costa Rica. Calcium concentrations of egg components [eggshell, yolk plus albumen (Y+A) and embryo] changed significantly through incubation for both viable and undeveloped eggs. In developed eggs, eggshell calcium content decreased 42.9% by day 60 of incubation. The Y+A calcium decreased by 20.8% until the last quarter of incubation, and then increased to 0.99% above initial Y+A calcium concentrations just prior to hatching. In undeveloped eggs, eggshell calcium content decreased by 25.7%, with the rate of decrease slowing significantly beyond day 30 of incubation. In contrast, Y+A calcium increased steadily through the 60-day incubation period. Embryos incorporated a higher proportion of calcium when incubated at a lower sand moisture content (5% H(2)O>12% H(2)O) and at lower sand temperatures (28.5 degrees C, 29.5 degrees C>31.0 degrees C). The total wet mass of freshly oviposited eggs was negatively correlated with calcium concentration per gram of eggshell (r=-0.569; P<0.001). Thus, each yolked egg, regardless of initial wet mass, had an average of 1.23 g (+/-0.43 g) of calcium per egg (Mean egg mass: 76.24+/-1.21 g). Both developmental success (24.1%) and hatching success (7.4%) of laboratory-incubated eggs were dependent to a greater extent on temperature than on moisture, with an increase in mortality as sand temperature increased. For natural nests on Playa Grande, developmental success (37.4%) and hatching success (19.8%) were similar in magnitude to the results obtained from the laboratory. The recent ENSO (El Nino Southern Oscillation) event and increased tidal activity may be responsible for the high embryonic mortality measured during the 1997-1998 nesting season.
TL;DR: The short-term inhibitory effects of LAS on soil microbiology were decreased in the presence of sewage sludge and by a prolonged laboratory incubation period.
Abstract: The anionic surfactant linear alkylbenzene sulfonate (LAS) may inhibit soil microorganisms and may occur in agricultural soil through the application of sewage sludge. For five microbial parameters (microbial biomass C and the potentials of iron reduction, ammonium oxidation, dehydrogenase activity, and arylsulfatase activity), we compared the effects of aqueous LAS and LAS-spiked sewage sludge added to existing levels of 0, 3, 8, 22, 22, 62, 174, and 488 mg/kg soil (dry wt) in a Danish sandy agricultural soil that was incubated for 5 d to eight weeks. Arylsulfatase activity (measured after four weeks of incubation) was rather insensitive to LAS, with an EC 10 of 222 and more than 488 mg/kg in soil samples treated with aqueous LAS and LAS-spiked sewage sludge, respectively. For the other microbial parameters, the short-term effects (approximately one to two weeks) of aqueous LAS were characterized by an EC10 in the range of 3 to 39 mg/kg. Application of LAS via sewage sludge generally reduced the short-term effects for the microbial parameters, and the EC10 for LAS in sludge-amended soil after approximately one to two weeks of incubation ranged from less than 8 to 102 mg/kg. Recovery potential was seen for most microbial parameters as a result of prolonged incubation, both under conditions of LAS persistence (anaerobic conditions, the iron-reduction test) and LAS depletion (aerobic incubations, all other assays). In conclusion, the short-term inhibitory effects of LAS on soil microbiology were decreased in the presence of sewage sludge and by a prolonged (two to eight weeks) laboratory incubation period.
TL;DR: Two experiments were conducted to study the effect of in vitro hydrolysis of phytate on the nutritional value of canola meal for broiler chickens and both purified and crude phytases improved AME n but only purified phytase improved amino acid availability.
TL;DR: The results suggest that the conductance constant principle, which describes the relationship among egg weight, length of incubation, and eggshell conductance, can be used in commercial hatcheries to improve embryo survival and poult quality.
Abstract: SUMMARY Embryonic growth relationships exist for egg weight, eggshell conductance, and length of the incubation period. These relationships have been well established for comparisons of embryonic development across species; however, very little is known about these relationships within a species. The hypothesis was tested that survival of embryos in turkey eggs could be changed by manipulating incubation periods. Fertile eggs were obtained three times from the same breeder flocks (two strains). Two incubator temperature treatments were used to create two different incubation periods for the eggs. Eggs produced at 33 weeks of age hatched better at shorter incubation periods, eggs produced at 43 weeks of age hatched equally well at both incubation temperatures, and eggs produced at 54 weeks of age hatched better at longer incubation periods. Livability for 5 days in brooder houses was highly variable but indicated survival differences between strains. Additionally, longer incubation periods produced poults that lived better than did controls. The results suggest that the conductance constant principle, which describes the relationship among egg weight, length of incubation, and eggshell conductance, can be used in commercial hatcheries to improve embryo survival and poult quality.
TL;DR: Phospholipase production by various isolates of Pseudomonas was investigated and pasteurization reduced the activity, but did not eliminate it in skim milk.
Abstract: Many psychrotrophic bacteria contaminating raw milk produce phospholipase that withstands pasteurization and UHT treatments. This enzyme acts on the milk fat globule membrane and exposes triacylglycerides to the action of lipase. Phospholipase production by various isolates of Pseudomonas was investigated. The isolates were cultured aerobically at 8 °C in nutrient broth, McKellar's minimal salts medium, Chrisope's medium, and skim milk. Each strain produced phospholipase during the 50 h incubation. Enzyme production varied significantly (P < 0·001) with strain and growth medium. Strains varied significantly (P < 0·001) in their enzyme production in each medium and during the incubation time as well. Strain, incubation time, and the growth medium significantly influenced (P < 0·001) heat stability of the enzyme activity. Pasteurization reduced the activity, but did not eliminate it in skim milk.