Showing papers on "Incubation published in 2005"
TL;DR: The data show that in eiders, a long-lived species, the cost of high incubation demand is paid in the currency of reduced future fecundity, possibly mediated by reduced immune function.
Abstract: Life-history theory predicts that increased current reproductive effort should lead to a fitness cost. This cost of reproduction may be observed as reduced survival or future reproduction, and may be caused by temporal suppression of immune function in stressed or hard-working individuals. In birds, consideration of the costs of incubating eggs has largely been neglected in favour of the costs of brood rearing. We manipulated incubation demand in two breeding seasons (2000 and 2001) in female common eiders (Somateria mollissima) by creating clutches of three and six eggs (natural range 3-6 eggs). The common eider is a long-lived sea-duck where females do not eat during the incubation period. Mass loss increased and immune function (lymphocyte levels and specific antibody response to the non-pathogenic antigens diphtheria and tetanus toxoid) was reduced in females incubating large clutches. The increased incubation effort among females assigned to large incubation demand did not lead to adverse effects on current reproduction or return rate in the next breeding season. However, large incubation demand resulted in long-term fitness costs through reduced fecundity the year after manipulation. Our data show that in eiders, a long-lived species, the cost of high incubation demand is paid in the currency of reduced future fecundity, possibly mediated by reduced immune function.
307 citations
TL;DR: Chicks that hatched from eggs incubated at low EST during wk 1 of incubation had lower rectal temperature after hatching, especially under low housing temperatures, and this effect lasted until 7 d posthatch in batch 1, and the highest rectal temperatures were always found in chicks incubation at 37.8 degrees C EST constantly throughout incubation.
268 citations
TL;DR: It is concluded that current granular measures of spawning and incubation habitat quality do not satisfactorily describe the complexity of factors influencing incubation success and casts doubt over the ability of current catchment-based land use management strategies to adequately reduce fine sediment inputs.
259 citations
TL;DR: Investigation of the effect of tea saponins on ruminal fermentation in vitro using gas syringes as incubators found that inclusion with 2, 4, 6 and 8 mg of TS decreased methane concentration by 13, 22, 25 and 26%, respectively.
243 citations
TL;DR: There was a negative association between TBARS and motility, suggesting that lipid peroxidation affected sperm motility and the addition of 200 microg/mL alpha-tocopherol in the semen extender could be useful to preserve boar spermatozoa against the oxidative stress generated by cryopreservation.
170 citations
TL;DR: The results show that hatching experiments aimed at assessing cladoceran species richness and conducted at 15 � C should be continued for a period of at least 2 weeks, after which a random subset of hatchlings can be selected from the total hatchling assemblage.
Abstract: SUMMARY 1. We identified temperature and photoperiod conditions under which the hatching of 45 cladoceran species could be elicited. Identification of appropriate hatching cues is of primary importance for the exploration of the ties between active and diapausing stages. 2. Incubation temperature affected the hatching success of resting eggs isolated from Danish, Belgian/Dutch and Spanish sediments. In general, most hatchlings and species were retrieved at 15 � C. Danish and Belgian/Dutch resting eggs hatched more successfully under a long day photoperiod than in continuous illumination. 3. Most species could be retrieved after incubation of resting eggs isolated from a limited amount of sediment (0.4 kg) under a single, well chosen combination of temperature and photoperiod. Processing additional sediment samples under seven more incubation regimes only allowed detection of 21% (Spain) to 34% (Denmark) more species. 4. The incubation period for resting eggs to hatch was strongly influenced by incubation temperature. Our results show that hatching experiments aimed at assessing cladoceran species richness and conducted at 15 � C should be continued for a period of at least 2 weeks, after which a random subset of hatchlings (e.g. n ¼ 100) can be selected from the total hatchling assemblage.
154 citations
TL;DR: First evidence that microbes can infect unincubated eggs of a wild bird is provided, and that infection and ambient temperature act independently to reduce hatching success is provided.
Abstract: Many avian species initiate incubation before clutch completion, which causes eggs to hatch asynchronously. This influences brood competitive dynamics and often results in nestling mortality. The prevailing hypotheses contend that parents incubate early because asynchronous hatching provides fitness benefits to parents or surviving offspring. An alternative idea is that early incubation is the best of a bad job because of the costs of delaying incubation to the viability of first-laid eggs. To explore this, we examined the potential for microbial infection, and the relative effects of infection and suboptimal development temperatures on the viability of pearly-eyed thrasher (Margarops fuscatus) eggs. We exposed newly laid eggs for 5 days at either end of a tropical altitudinal gradient and cleaned shells of half the eggs to reduce microbial growth. Uncleaned eggs were infected more than were cleaned eggs, and infection was greater for eggs exposed at the cool, humid site than at the hot, less humid site. Parentally incubated eggs, however, were not infected, suggesting that incubation limits infection. The consequence of exposure to infection and high ambient temperatures was a dramatic reduction in viability; cleaned eggs held at the cool site had the highest hatching success, which was significantly greater than for uncleaned eggs at this site and for cleaned eggs held at the hot site. This provides the first evidence that microbes can infect unincubated eggs of a wild bird, and that infection and ambient temperature act independently to reduce hatching success. These factors could affect avian life-history strategies in diverse habitats. Key words: ambient temperature, egg viability, hatching asynchrony, onset of incubation, saprophytic microorganism, trans-shell transmission. [Behav Ecol]
141 citations
TL;DR: A decrease was observed in caffeine content of the coffee pulp samples during fruiting stage, which could mean that some caffeine accumulates in the fruiting bodies of Pleurotus.
137 citations
TL;DR: PCP degradation was associated with significant changes in bacterial community structure, leading to the appearance of seven bands in both DNA- and RNA-based DGGE profiles, the latter providing clearer evidence of qualitative shifts in community structure.
Abstract: Summary The central aim of this study was to determine which components of an indigenous bacterial community in pristine grassland soil were capable of degrading pentachlorophenol (PCP) using two cultivation- independent, in situ , molecular techniques. The first involved polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT- PCR) amplification of 16S rRNA genes from DNA and RNA, respectively, extracted from PCP-amended soil. The second involved stable isotope probing (SIP), with incubation of soil with 13 C-PCP and molecular analysis of 13 C-labelled RNA, derived from cells incor- porating PCP or its breakdown products, after sepa- ration from 12 C-RNA by ultracentrifugation. Bacterial communities were characterized by denaturing gradi- ent gel electrophoresis (DGGE) analysis of amplifica- tion products. PCP was degraded at an approximate rate of 1.18 ± 0.25 (SEM) mg kg - 1 day - 1 and 39% of the measurable PCP fraction was degraded after incuba- tion for 63 days. PCP degradation was associated with significant changes in bacterial community structure, leading to the appearance of seven bands in both DNA- and RNA-based DGGE profiles, the latter providing clearer evidence of qualitative shifts in community structure. The majority of novel bands increased in relative intensity during the first 35 days and subsequently decreased in relative intensity as incubation continued. Sequence and phylogenetic analysis of six of these bands indicated most to have closest database relatives that were uncultured bac- teria with sequence homologies to reported hydrocar- bon degraders. No band could be detected in RNA- SIP-DGGE profiles derived from 13 C-RNA fractions at day 0 but several faint bands appeared in these frac- tions after incubation of soil for 4 days, indicating assimilation of PCP or its degradation products. These bands increased in intensity during subse- quent incubation for 21 days and decreased with fur- ther incubation. With one exception, RNA-SIP-DGGE and RNA-DGGE profiles were similar, indicating that RNA-targeted DGGE, in this case, provided a good indication of the metabolically active microbial community.
123 citations
TL;DR: In this paper, the physicochemical properties and structural characteristics of microbial transglutaminase (MTGase)-induced biopolymers of sodium caseinate (SC) were investigated.
Abstract: Some physicochemical properties and structural characteristics of microbial transglutaminase (MTGase)-induced biopolymers of sodium caseinate (SC) were investigated. The sodium dodecyl sulfatepolyacrylamide gel electrophoresis and size-exclusionhigh-performance liquid chromatography analyses showed that all components of SC were easily polymerized or transformed by MTGase to form high-molecular weight biopolymers, and the susceptibility order of individual components was kappa-Casein (C) > alpha-C > beta-C. The emulsifying properties of biopolymers depended on the incubation time with MTGase. The emulsifying activity index of biopolymers persistently increased with the MTGase (0-12 h) incubation time. The emulsion stability also increased with the incubation time (< 4 h), then declined a little with longer incubation (412 h). The differential scanning calorimetry analysis showed that the thermal properties of the biopolymers obtained after a 12-h incubation were different from that of native SC or biopolymers obtained after a shorter incubation time (< 4 h), suggesting that the former has higher thermal stability. In addition, the ultraviolet (UV) spectra showed that the UV absorbance (at 275 nm) of MTGase-induced biopolymers of SC decreased with an increasing incubation time with MTGase, and the maximal emission wavelength (lambda(max)) slightly shifted to the "blue side." The fluorescence spectra showed that the lambda(max) was related with incubation time with MTGase, slightly shifting to the "blue side" after 4 h with no further changes; its relative fluorescence intensity also increased. These results suggest a relationship between the functionalities and structural characteristics of the MTGase-induced biopolymers of SC.
122 citations
TL;DR: The findings suggest that these drugs act by decreasing the rate of hemozoin formation, rather than irreversibly blocking its formation, which can also explain the observation of a sigmoidal dependence of β-hematin inhibition on drug concentration.
TL;DR: The data suggest a sex-biased temperature-sensitive embryo mortality because mortality was greater at the lower and higher temperatures, and minimal at the middle temperature where the sex ratio was 1 : 1.
Abstract: To our knowledge, there is, so far, no evidence that incubation temperature can affect sex ratios in birds, although this is common in reptiles. Here, we show that incubation temperature does affect sex ratios in megapodes, which are exceptional among birds because they use environmental heat sources for incubation. In the Australian brush-turkey Alectura lathami, a mound-building megapode, more males hatch at low incubation temperatures and more females hatch at high temperatures, whereas the proportion is 1:1 at the average temperature found in natural mounds. Chicks from lower temperatures weigh less, which probably affects offspring survival, but are not smaller. Megapodes possess heteromorphic sex chromosomes like other birds, which eliminates temperature-dependent sex determination, as described for reptiles, as the mechanism behind the skewed sex ratios at high and low temperatures. Instead, our data suggest a sex-biased temperature-sensitive embryo mortality because mortality was greater at the lower and higher temperatures, and minimal at the middle temperature where the sex ratio was 1:1.
TL;DR: The main responses elicited by chronic hypoxic incubation, namely, cardiac enlargement, blunted hypoxic response and systemic vasodilation, may provide chronically hypoxic embryos with a new physiological repertoire for responding to hypoxia.
Abstract: Chronic hypoxic incubation is a common tool used to address the plasticity of morphological and physiological characteristics during vertebrate development. In this study chronic hypoxic incubation of embryonic American alligators resulted in both morphological (mass) and physiological changes. During normoxic incubation embryonic mass, liver mass and heart mass increased throughout the period of study, while yolk mass fell. Chronic hypoxia (10%O2) resulted in a reduced embryonic mass at 80% and 90% of incubation. This reduction in embryonic mass was accompanied by a relative enlargement of the heart at 80% and 90% of incubation, while relative embryonic liver mass was similar to the normoxic group. Normoxic incubated alligators maintained a constant heart rate during the period of study, while mean arterial pressure rose continuously. Both levels of hypoxic incubation (15% and 10%O2) resulted in a lower mean arterial pressure at 90% of incubation, while heart rate was lower in the 10%O2 group only. Acute (5 min) exposure to 10%O2 in the normoxic group resulted in a biphasic response, with a normotensive bradycardia occurring during the period of exposure and a hypertensive tachycardic response occurring during recovery. The embryos incubated under hypoxia also showed a blunted response to acute hypoxic stress. In conclusion, the main responses elicited by chronic hypoxic incubation, namely, cardiac enlargement, blunted hypoxic response and systemic vasodilation, may provide chronically hypoxic embryos with a new physiological repertoire for responding to hypoxia.
TL;DR: It is concluded that although lactate/lactic acid incubation regains force in K+‐depressed resting muscle, a similar incubation has no or a negative effect on force development in active muscle.
Abstract: Lactic acid accumulation is generally believed to be involved in muscle fatigue. However, one study reported that in rat soleus muscle (in vitro), with force depressed by high external K+ concentrations a subsequent incubation with lactic acid restores force and thereby protects against fatigue. However, incubation with 20 mm lactic acid reduces the pH gradient across the sarcolemma, whereas the gradient is increased during muscle activity. Furthermore, unlike active muscle the Na+–K+ pump is not activated. We therefore hypothesized that lactic acid does not protect against fatigue in active muscle. Three incubation solutions were used: 20 mm Na-lactate (which acidifies internal pH), 12 mm Na-lactate +8 mm lactic acid (which mimics the pH changes during muscle activity), and 20 mm lactic acid (which acidifies external pH more than internal pH). All three solutions improved force in K+-depressed rat soleus muscle. The pH regulation associated with lactate incubation accelerated the Na+–K+ pump. To study whether the protective effect of lactate/lactic acid is a general mechanism, we stimulated muscles to fatigue with and without pre-incubation. None of the incubation solutions improved force development in repetitively stimulated muscle (Na-lactate had a negative effect). It is concluded that although lactate/lactic acid incubation regains force in K+-depressed resting muscle, a similar incubation has no or a negative effect on force development in active muscle. It is suggested that the difference between the two situations is that lactate/lactic acid removes the negative consequences of an unusual large depolarization in the K+-treated passive muscle, whereas the depolarization is less pronounced in active muscle.
TL;DR: It is suggested that sex difference in oocyte growth and egg-laying sequence is an adaptive outcome of hormonal constraints imposed by the overlap of early incubation and oogenesis in this population, and that the close integration of maternal incubation, oocytes' sex-determination and growth might be under control of the same hormonal mechanism.
Abstract: Maternal modification of offspring sex in birds has strong fitness consequences, however the mechanisms by which female birds can bias sex of their progeny in close concordance with the environment of breeding are not known. In recently established populations of house finches (Carpodacus mexicanus), breeding females lay a sex-biased sequence of eggs when ambient temperature causes early onset of incubation. We studied the mechanisms behind close association of incubation and sex-determination strategies in this species and discovered that pre-ovulation oocytes that produce males and females differed strongly in the temporal patterns of proliferation and growth. In turn, sex-specific exposure of oocytes to maternal secretion of prolactin and androgens produced distinct accumulation of maternal steroids in oocyte yolks in relation to oocyte proliferation order. These findings suggest that sex difference in oocyte growth and egg-laying sequence is an adaptive outcome of hormonal constraints imposed by the overlap of early incubation and oogenesis in this population, and that the close integration of maternal incubation, oocytes' sex-determination and growth might be under control of the same hormonal mechanism. We further document that population establishment and the evolution of these maternal strategies is facilitated by their strong effects on female and offspring fitness in a recently established part of the species range.
TL;DR: Mechanistic models that account for the biology of spore clearance and germination are developed based on a competing risks formulation and suggest that male gender and younger ages were associated with longer incubation periods as was lower dose of inhaled spores.
Abstract: Models of the incubation period of anthrax are important to public health planners because they can be used to predict the delay before outbreaks are detected, the size of an outbreak and the duration of time that persons should remain on antibiotics to prevent disease. The difficulty is that there is little direct data about the incubation period in humans. The objective of this paper is to develop and apply models for the incubation period of anthrax. Mechanistic models that account for the biology of spore clearance and germination are developed based on a competing risks formulation. The models predict that the incubation period distribution depends critically on the rate that spores are cleared from the lung and to a lesser extent on the dose of inhaled spores. The models are used in a statistical analysis of data from an anthrax outbreak that occurred in Sverdlovsk, Russia. The analysis suggests that spores are cleared from the lung at a rate between 8 per cent per day and 14 per cent per day, which is in good agreement with experimental studies of animals. The analysis suggests that at low doses, the overall median incubation period time is about 10 days, which includes a median lag of about 2 days between spore germination and onset of symptoms. Male gender and younger ages were associated with longer incubation periods as was lower dose of inhaled spores.
TL;DR: The data show that there is a significant relationship between cytokine production and ozone concentrations and that PBMC are very sensitive to oxidation particularly in presence of serum with low antioxidant capacity.
Journal Article•
TL;DR: It is concluded that ELF-MF influences antioxidative enzyme activities and increases lipid peroxidation in 3T3-L1 preadipocyte cultures.
Abstract: The exposure to extremely low frequency electromagnetic field (ELF-MF, frequencies less than 200-300 Hz) can alter the transcription and translation of genes, influence the cell proliferation rate and affect enzyme activities Moreover, the hypothesis that ELF-MF increases free oxygen metabolites generation has been proposed Since recent in vivo studies suggest that electric and magnetic fields are able to affect adipose cells metabolism The aim of the study was to examine the effects of ELF-MF (frequency of basic impulse 180-195 Hz, induction 120 microT) on cell proliferation, antioxidative enzyme activities and malondialdehyde (MDA) concentration in 3T3-L1 preadipocyte cell culture We found that ELF-MF application lasting 36 minutes daily failed to influence cell count after 24h and 48 h of incubation After 24 h, in the ELF-MF treated group, manganese- and copper-zinc-containing superoxide dismutase (MnSOD and Cu/ZnSOD) isoenzymes media activities were decreased, catalase activity was increased, whereas there were no significant differences in glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-Rd) activities in comparison to the control After 48 h of incubation, all enzyme activities were reduced, except for GSSG-Rd, in which no changes were noticed MDA concentration at 24 h after incubation with the exposure to ELF-MF was significantly higher in comparison to the control, without ELF-MF After 48 h of incubation, MDA levels were significantly lower in both groups with no differences between the groups without and with ELF-MF We conclude that ELF-MF influences antioxidative enzyme activities and increases lipid peroxidation in 3T3-L1 preadipocyte cultures
TL;DR: In this article, the authors evaluated the degradability of tumbleweed hay harvested at three stages by chemical composition, in vitro (gas production) and in situ dry matter degradation methods.
TL;DR: Under capacitating conditions (TCM), the coefficients of linearity (LIN) and straightness (STR) significantly increased over time and suggests that capacitated boar spermatozoa may have a species-specific motility pattern.
TL;DR: It is concluded that the shade of brown pigment, intensity of light during incubation and age of the breeder hens influenced the hatchability performance of embryos from brown eggs.
Abstract: 1. The effects of intensity of brown eggshell pigment (light (LBP), medium (MBP) and dark (DBP)) and light intensity during incubation (low and high, 900 to 1380 and 1430 to 2080 lux, respectively) on eggshell characteristics, embryonic growth, hatchability traits, chick hatching weight and hatching time were investigated using eggs from a meat-type breeder (Hybro) flock at 32, 36 and 41 weeks of age in three trials. 2. With eggs of similar weights the intensity of brown pigment was not associated with eggshell weight and thickness, and did not influence embryo weight and egg weight loss during incubation. 3. The shade of brown pigment of eggs laid by young hens influenced the percentage hatchability (HP) of eggs incubated under light. Illuminated incubation improved HP of LBP eggs (compared with MBP and DBP eggs) from 32- and 36-week-old hens, but had no significant effect on HP of eggs from 41-week-old hens. 4. Light intensity during incubation did not influence egg weight loss. High intensity of light ...
TL;DR: Results show that suppressive effects of T on male parental care generalize to incubation behaviour in this species and reinforce the view of T as a mediator of trade-offs between parental and mating effort.
TL;DR: Analysis after 1, 7 and 14 days showed that incubation temperature and storage time significantly influenced overall properties of the samples, but titratable acidity, lactic acid and volatile fatty acid contents increased.
Abstract: Yogurt and bio-yogurt were manufactured from ewe s milk using a starter culture and a probiotic culture. Incubation was carried out at 3 7 °C and 42 °C until pH 4.6 was reached and the yogurts were stored at 4 +1°C for 14 days. Analysis after 1, 7 and 14 days showed that incubation temperature and storage time significantly influenced overall properties of the samples. During the storage, whey separation andpH decreased, but titratable acidity, lactic acid and volatile fatty acid contents increased. Viable bacterial counts in all bio-yogurts were above 10 7 cfu g -1 at the end of storage.
TL;DR: Results showed that M2 was better fit than M1 for describing the ecological toxicity dose effect of cadmium on soil microbial biomass and its activity in a paddy soil and the ecological dose increased in turn with increased incubation time.
Abstract: Cadmium (Cd) is ubiquitous in the human environment and has toxic effect on soil microbial biomass or its activity, including microbial biomass carbon (Cmic), dehydrogenase activity (DHA) and basal respiration (BR), etc., Cmic, DHA, BR were used as bioindicators of the toxic effect of Cd in soil. This study was conducted to determine the effects of Cd on soil microbial biomass and its activity in a paddy soil. The inhibition of microbial biomass and its activity by different Cd concentrations was described by the kinetic model (M1) and the sigmoid dose-response model (M2) in order to calculate three ecological doses of Cd: ED50, ED10 and ED5. Results showed that M2 was better fit than M1 for describing the ecological toxicity dose effect of cadmium on soil microbial biomass and its activity in a paddy soil. M2 for ED values (mg/kg soil) of Cmic, DHA, BR best fitted the measured paddy soil bioindicators. M2 showed that all ED values (mg/kg) increased in turn with increased incubation time. ED50, ED10 and ED5 of Cmic with M2 were increased in turn from 403.2, 141.1, 100.4 to 1000.7, 230.9, 144.8, respectively, after 10 d to 60 d of incubation. ED50, ED10 and ED5 of DHA with M2 increased in turn from 67.6, 6.2, 1.5 to 101.1, 50.9, 41.0, respectively, after 10 d to 60 d of incubation. ED50, ED10 and ED5 of BR with M2 increased in turn from 149.7, 6.5, 1.8 to 156.5, 50.8, 35.5, respectively, after 10 d to 60 d of incubation. So the ecological dose increased in turn with increased incubation time for M2 showed that toxicity of cadmium to soil microbial biomass and its activity was decreased with increased incubation time.
TL;DR: Silage fermentation acids appeared to interfere with relationships between gas production and in vitro substrate degradability measures because they were removed from the incubation residue without having contributed to fermentation, and silage acids should be accounted for when using combined in vitroGas production and true substrate de gradability estimates to evaluate EMP of silage-based diets.
TL;DR: The largest stress response occurred during late incubation and was independent of sex, although males were in relatively poor condition and females in relatively good condition, and birds may be physiologically primed for extended fasts.
Abstract: We report the results of the first field study examining seasonal changes in corticosterone responses of typically long-lived birds of the order Procellariiformes. In particular, we examined whether grey-faced petrels Pterodroma macroptera gouldi showed changes in circulating baseline corticosterone concentrations and corticosterone responses to a standardized handling protocol across the breeding season. Such changes have been associated with changes in body condition and variations in energy demands on adult birds through the breeding season. During early incubation, males were in significantly better condition than females that had just completed laying, whereas during late incubation, males were in significantly poorer condition than females. In spite of these differences, there was no significant difference in baseline corticosterone concentrations between sexes or among birds at different reproductive stages. However, we detected significant differences in corticosterone responses associated with a standardized handling protocol at different stages through the breeding season. Responses were significantly greater during incubation compared with the prelay period and late chick rearing. Body condition was weakly and negatively correlated with maximum and total integrated corticosterone level, indicating that some of the individual variability in stress corticosterone responses could be explained by variation in body condition. However, the largest stress response occurred during late incubation and was independent of sex, although males were in relatively poor condition and females in relatively good condition. This period coincided with the breeding stage in which energy constraints on individual adults were higher than at other periods of the reproductive cycle and birds may be physiologically primed for extended fasts.
TL;DR: Variation in &dgr;13C composition of individual phospholipid fatty acids (PLFA) during the incubation indicated that different components of the microbial community played different roles in the cycling of the added glucose.
Abstract: A short-term incubation of soil amended with 13 C-glucose was conducted to determine the extent of labeled C recycling that might occur within the microbial community. Changes in the production and isotopic composition of CO 2 and biomass suggest that two phases of microbial activity occurred after the glucose addition. The initial phase due directly to the metabolism of the added glucose was characterized by an increase in biomass and a high growth efficiency. A second phase appeared to be driven by less available substrates (e.g., cell wall structures, soil organic matter) and characterized by insignificant changes in biomass but significant generation of CO 2 suggestive of low growth efficiency. Glucose-C supported 12 to 73% of the CO 2 -C evolved and 17 to 21% of biomass-C, suggesting glucose was the principle energy rather than a C source during the 15- to 48-hour phase of the incubation. Variation in δ 13 C composition of individual phospholipid fatty acids (PLFA) during the incubation indicated that different components of the microbial community played different roles in the cycling of the added glucose. The most enriched δ 13 C values were initially those PLFA associated with Gram-positive bacteria, suggesting they were responsible for much of the initial incorporation. By contrast, at the end of the 48-hour incubation, 4 of 24 PLFA biomarkers were not labeled with 13 C. Actinomycetes, however, probably played a larger role in the use of recycled glucose-derived C, as suggested by the enrichment in 13 C of 10-methyl 18:0 PLFA after the exhaustion of glucose. Results from this study show that the element of time needs to be considered carefully in the interpretation of any stable isotope labeling and biomarker study.
TL;DR: In this article, the effect of maturity stage on the nutritive value of wild mustard straw in terms of chemical composition, in situ, in vitro dry matter degradability and calculated ME was determined.
Abstract: The aim of this study was to determine the effect of maturity stage on the nutritive value of wild mustard straw in terms of chemical composition, in situ, in vitro dry matter degradability and calculated ME. The nutritive values of wild mustard, Sinapsis arvensis hays harvested at three stages were evaluated by chemical composition, in vitro gas production and in situ dry matter degradation methods. Gas production or dry matter (DM) degradation were determined at 0, 3, 6, 12, 24, 48, 72 and 96 h and their kinetics were described using the equation p = a+b(1-e -ct ). Maturity had a significant effect on both the chemical composition and degradability of wild mustard. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) (p<0.001) increased with increasing maturity whereas the crude protein (CP) (p<0.001) decreased. The gas produced after 96 h incubation ranged between 64.7 and 81.5 ml per 0.200 g of dry matter. The gas production (ml) at all incubation times and estimated parameters decreased with increasing maturity of wild mustard. The gas production at all incubation times and estimated parameters (a, b (a+b), metabolizable energy (ME) and organic matter digestibility (OMD)) were negatively correlated with NDF and ADF. The DM disappearance after 96 h incubation ranged between 50.8 and 76.1%. The in situ DM disappearance at all incubation times and estimated parameters decreased with increasing maturity of wild mustard. The in situ dry matter disappearance at all incubation times and some estimated parameters (c, a, b and effective dry matter degradability (EDMD)) were negatively correlated with NDF and ADF but positively correlated with CP. The nutritive value of wild mustard continually changed as it matured. Wild mustard, harvested at the proper stage of maturity offers considerable potential as a high quality forage for ruminants during the winter feeding period. The present study showed that if higher quality forage is an objective, wild mustard should be harvested at the early flowering stage. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 9 : 1249-1254)
Journal Article•
TL;DR: In this paper, a single strain E. coli serotype O157:H7, isolated from milk in Poland, was examined in water environment (water, bottom-shore sediments and in muddy water over sediments) at 6°C and 24°C.
Abstract: Survival of a single strain E. coli serotype O157:H7, isolated from milk in Poland, was examined in water environment (water, bottom-shore sediments and in muddy water over sediments) at 6°C and 24°C. Pathogenic bacteria were not detected (direct plating method) in water within 32 and 51 days of incubation at 6°C and within 21 and 32 days of incubation at 24°C (except water from one of the rivers, where the disappearance of serotype O157:H7 was noticed only after 54 incubation days). The target bacteria survived in muddy water 49-65 days at 6°C and 26-60 days at 24°C. Bacteria died at the slowest rate in bottom-shore sediments. The disappearance of the enterohemorrhagic serotype in these environmental materials was noticed only after 73-100 (6°C) and 30-60 (24°C) incubation days. The obtained results evidently indicate the existence of possible hazards connected with relatively long survival periods of pathogenic bacteria in water environment. The bottom-shore sediments in particular can be a reservoir of this bacteria.
TL;DR: For example, this paper examined male and female incubation contributions in House Sparrows (Passer domesticus), quantifying the incubation behavior of free-living, individually color-banded parents during 47 nesting cycles.
Abstract: In the great majority of animal taxa, males do not participate in parental care, but substantial paternal care is common across avian species. We examined male and female incubation contributions in House Sparrows (Passer domesticus), quantifying the incubation behavior of free-living, individually color-banded parents during 47 nesting cycles. We also measured the relative warmth of male and female incubation surfaces. Females spent more time incubating than their male partners, and female time incubating served as the best single predictor for hatching success. Considered alone, male time incubating correlated negatively with hatching success, but that effect was nullified when female incubation was taken into account. Females had warmer abdomens than males, a difference that may reflect greater development of brood patch and effectiveness of incubation in that sex. Here, male badge size was not demonstrably associated with either male or female incubation patterns or hatching success. Division...