The influence of environmental conditions on the production of pigment bySerratia marcescens

Serratia marcescens biovar A2/A6, isolated from an Indonesian freshwater source, was identified based on extensive morphological, biochemical and genetic characterization. Formation of pigment was found to be strongly influenced by environmental conditions. Placket-Burman design was used to analyze the effect of carbon and nitrogen sources. Based on results of physiological and biochemical studies, the optimum conditions for growth and pigment formation were incubation 30°C in a neutral to slightly alkaline medium containing lactic acid and beef extract.     

The influence of environmental conditions on the reproduction and distribution of epilithic lichens

Summary Humidity and solar radiation condition the distribution of lichen communities on the nuraghi of northwestern Sardinia.The growth of lichens withTrentepohlia algae is favored to the north under conditions of low light intensity and high humidity. Lichens with cyanobacteria prevail under dry conditions. Microclimatic conditions also generate selective pressures on the reproductive strategies of the species.Vegetative reproduction through soredia is maximum under extreme conditions: minimum light intensity and maximum humidity on one hand; maximum light intensity and minimum humidity on the other.For vegetative reproduction through isidia, no significant correlation was found with humidity and light: the maximum frequency of isidia was found in situations with a flow of rainwater.Gametic reproduction through spores has a very high frequency (> 80%) in intermediate microclimatic situations.     

The influence of snow conditions on the date of breeding of wading birds in north-east Greenland

The young of wading birds that breed in some parts of the arctic hatch when their insect food supply is most abundant. This appears to be the ultimate factor determining the date of egg-laying. In various other arctic birds the date of breeding may be influenced, directly or indirectly, by the time at which snow or ice melts. The Joint Biological Expedition to N.E. Greenland 1974 studied Ringed plovers Charadrius hiaticula , Dunlins Calidris aplina , Sanderlings Calidris alba , Knots Calidris canutus , and Turnstones Arenaria interpres breeding in various areas within 80 km of each other.
In 1974 the thaw was two or three weeks later than normal in the region. The time at which snow cleared and the dates of breeding of the waders differed considerably between valleys: breeding was delayed in valleys that cleared late. In all areas egg-laying ceased early in July, probably because chicks hatching from eggs laid later would not be ready to migrate by the end of the summer. Hence the mean date and length of the egg-laying period were determined by the date of snow clearance from the breeding areas.
Studies of the potential food resources indicate that the waders in N.E. Greenland do not appear to time their breeding so that the young hatch at some peak of food abundance. Sufficient food resources are probably available over a long period of time.     

The influence of food on time budgets and timing of breeding of the Dunnock Prunella modularis

In two years, we provided some female Dunnocks with extra food from January through to July. In one year fed females bred ten days earlier than controls and in another year they bred 22 days earlier, but in neither year did they lay larger clutches. Matched comparisons of the same females on the same territories, who had food in one year but not in the other, showed the same effects. Within both feeder and control females, the earliest breeders were those which had spent more time perching in late winter. Perching time may be a good measure of the time an individual has available above that needed for self maintenance. Therefore females who spent more time perching may have been those first able to cross the threshold of extra time needed for the start of breeding activities.     

The influence of conditions at the time of mating on reproduction of commercial pigs

The objective of this study was to compare a new mating system, called the Detection-Mating Area (DM Area), and a conventional mating system on the long-term reproductive performance of commercial pigs. The DM Area treatment basically involved detecting oestrous females in an arena closely surrounded on two sides by boars and mating these females in this arena. This mating system was designed to improve the physical and sexual environments of the pigs at mating. In contrast, the conventional treatment involved conducting oestrus detection and mating in the boar's accommodation pen. The study was conducted over an 18-month period at a commercial farm that housed 2400 breeding female pigs.

In order to control for the effects of the stockperson, an analysis was conducted on the reproductive performance of female pigs in which one stockperson assisted the matings in both treatments over a 12-month period. Gilts mated in the DM Area treatment had a higher (P<0.05) total litter size and a higher (P<0.01) litter size born alive than gilts mated in the conventional treatment (10.31 vs. 8.96 and 9.50 vs. 8.29, respectively). Although gilts in the DM Area treatment had a higher farrowing rate (93.2 vs. 87.9%), this difference was not significant (P>0.05). There were no significant (P>0.05) differences found between the reproductive performance of sows in the two treatments; however this comparison was confounded by sows in the DM Area treatment having a lower number of matings per oestrus than those in the other treatment. Observations on the sexual behaviour of pigs at 145 matings indicated that the boars in the DM Area treatment displayed a higher (P<0.05) number of bouts of courting behaviour directed towards the female than boars in the conventional treatment (8.3 and 6.4, respectively). These very limited observations on sexual behaviour suggest that changes in the courting behaviour of bears may be associated with changes in litter size. While there was some indication from the results of progesterone analysis of blood samples taken from unmated gilts that there may have been some differences between treatments in the sexual age of gilts at matings, these differences are unlikely to explain the differences in litter size between treatments. Further research is required to identify the component (s) of the DM Area treatment that are responsible for the improvement in litter size in gilts and to further examine the effects of the two treatments on the reproductive performance of sows.     

Age at menarche: the influence of environmental conditions

Age at menarche was studied by the recollection method in two groups of Causasian Jewish high school girls, inhabitants of two towns in Israel, Safad and Elat. The two towns differ mainly in climatic conditions. The age at menarche was found to be significantly lower (P<0.02) in the hot town of Elat than in the temperate town of Safad: 13.30±1.21 and 13.58±0.9 years, respectively (mean ±SD). A significant association was found between the age at menarche and the town in which the girls lived. Accordingly, in the hot town of Elat, the percentage of girls who had their first menstrual cycle by the age of 12 years and earlier, was more than double that of the girls in Safad (17.9% and 7.1%, respectively). It is concluded that the environmental temperature, with or without any possible interaction of humidity, is probably responsible for the tendency for an earlier onset of menarche in girls living in the hot town of Elat.     

Adverse environmental conditions influence age-related innate immune responsiveness

Background-  

The innate immune system plays an important role in the recognition and induction of protective responses against infectious pathogens, whilst there is increasing evidence for a role in mediating chronic inflammatory diseases at older age. Despite indications that environmental conditions can influence the senescence process of the adaptive immune system, it is not known whether the same holds true for the innate immune system. Therefore we studied whether age-related innate immune responses are similar or differ between populations living under very diverse environmental conditions.     

The influence of climatic conditions around the time of spraying isoproturon on the subsequent injury to barley

Winter barley cv. Igri was grown in pots, either outside under cover, in a glasshouse or under controlled conditions and treated post-emergence with isoproturon. There was a linear relationship between the subsequent weight of plants treated with 2.5 kg a.i./ha and either evaporation from a water surface between 2–7 days post spraying or cumulative temperature between sowing and spraying. The relationship between subsequent weight of plants treated to the foliage only with 5 kg a.i./ha and cumulative temperature between sowing and spraying varied between years 1984–86. The post spraying environment had the major influence on subsequent activity of isoproturon at 2.5 kg a.i./ha applied overall to barley under controlled conditions. There was a greater reduction in CO₂ exchange in plants grown after treatment under high compared to low relative humidity. When isoproturon at 5 kg a.i./ha was applied to barley plants with wet foliage, plants were slower to recover their initial rate of photosynthesis when kept wet for 24 h as compared with 11 h or when allowed to dry after treatment. Photosynthesis was decreased to a lesser extent under the same post spray conditions by 2.5 than by 5 kg a.i./ha and reduction was greater and recovery of photosynthesis slower in plants grown inside compared to outside.     

The influence of nutritional and environmental conditions on the accumulation of poly-beta-hydroxybutyrate in Bacillus mycoides RLJ B-017

AIMS: To optimize the nutritional and environmental conditions for growth of and poly-beta-hydroxybutyrate (PHB) accumulation in Bacillus mycoides RLJ B-017. METHODS AND RESULTS: An isolate, identified as B. mycoides, was grown on different sources of carbon and nitrogen. Among these, sucrose, beef extract and di-ammonium sulphate were found to be the most suitable for growth and PHB accumulation. The overall maximum value of PHB (%) in cells, PHB yield (Yp/s) and productivities (Qp and qp) were 69.4 +/- 0.4% dry cell weight (DCW), 0.21 gp gS(-1), 0.104 +/- 0.012 gp l(-1) h(-1) and 0.03 gp gx(-1) h(-1), respectively when grown in a medium containing 20 gs l(-1) sucrose, supplemented with di-ammonium sulphate. The addition of beef extract increased the value of PHB (%) in cells, PHB yield and productivities by 17.58 +/- 0,3, 23.8, 19.23 +/- 0.3 and 13.8 +/- 0.2% , respectively. The overall maximum values of PHB (% DCW), PHB yield and productivities were obtained at pH 7.0 +/- 0 .1, temperature 30 +/- 0.5 degrees C, agitation 650 rev min(-1) and oxygen transfer rate 3.8 mmol O(2) l(-1) h(-1). CONCLUSIONS: Sucrose, glucose and fructose were found to be more suitable for cell growth and PHB accumulation, but sucrose was less expensive than glucose. Among the nitrogen sources, beef extract and di-ammonium sulphate promoted PHB synthesis. The accumulation of PHB was observed to be growth associated. SIGNIFICANCE AND IMPACT OF THE STUDY: Gram-positive bacteria have not been reported to accumulate large amounts of polyhydroxyalkanoate and hence have not been considered as potent candidates for industrial production. A number of Bacillus spp. have been reported to accumulate 9-44.5% DCW PHB. By comparison, Bacillus RLJ B-017 contained 69.4 +/- 0.4% DCW PHB. Therefore, this strain has been considered as a potent organism for industrial interest. A relatively high yield of PHB was obtained in this wild strain and PHB synthesis was independent of nutrient limitation. The conditions for the higher PHB yield and productivity will be optimized in the next phase using fed-batch culture.     

The influence of experimental conditions on the spectrin-hemoglobin interaction

Human spectrin, when isolated, purified and stored in such conditions that preserve its tetrameric form, is able to associate with human hemoglobin as it is clearly shown by gel filtration. However, this hemoglobin-spectrin association does not seem to have a significant effect on hemoglobin oxygenation as indicated by equilibrium and rapid kinetics measurements.     

The influence of environmental change on the behaviour of sheltered dogs

The majority of sheltered dogs are overlooked for purchase because they are considered undesirable by potential buyers. Many factors may determine a dog's appeal, although of interest here are the dog's behaviour and cage environment which can influence its desirability. People prefer dogs which are at the front rather than the back of the cage, quiet as opposed to barking, and alert rather than non-alert. Potential buyers also prefer dogs which are held in complex as opposed to barren environments. This study examined the behaviour of sheltered dogs in response to environmental change, to determine whether it influenced dog behaviour in ways that could be perceived as desirable to potential dog buyers, and/or had any effect upon the incidence of dogs purchased from the shelter. One hundred and twenty dogs sheltered by the Ulster Society for the Prevention of Cruelty to Animals were studied over a 4-h period. The dogs' position in the cage, vocalisation, and activity were investigated in response to increased human social stimulation, moving the dog's bed to the front of the cage, or suspending a toy from the front of the dog's cage. Social stimulation resulted in dogs spending more time at the front of the enclosure, more time standing, and slightly more time barking. Moving the bed to the front of the cage encouraged dogs to this position, but did not influence activity or vocalisation. Suspending a toy at the front of the pen exerted no effect on dog behaviour, although its presence in the pen may help to promote more positive perceptions of dog desirability. The incidence of dogs purchased from the rescue shelter increased whenever the dogs' cages were fitted with a bed at the front of the pen, whenever the dogs were subjected to increased regular human contact, and whenever a toy was placed at the front of the enclosure. Findings highlight the important role that cage environment can play in shaping the behaviour of sheltered dogs and influencing whether or not an animal will become purchased.     

The complex influence of environmental factors on the state of microcirculation

The state of microcirculation system and its regulation in peace and after growing physical activity is analyzed on people living in different ecological regions. There are three main types of microcirculation. The level of regulation mechanisms activity depends on the type of microcirculation, region of residence and the value of physical activity. People living in a relatively clean regions have stable mechanisms of regulation despite of the level of activity. Mesoemic type living in toxic radiation regions have reduced contribution of VLF and LF-fluctuation (p < 0.05); hypoemic type living in toxic regions have VLF and LF-fluctuation (p < 0.05); hyperemic type living in toxic regions have LF-fluctuation (p < 0.05). We can conclude the tension of regulatory machanisms in microcirculation system increases under ecological pressure and borders on failure of adaptation process.     

The influence of environmental temperature on appetite-related hormonal responses

Background

Acute exercise in the heat has been shown to reduce appetite. However, the influence of exercise in the cold on appetite regulation remains unclear. The aim of this study was to compare exercise-induced appetite regulation under three different environmental temperatures.

Methods

Eleven male participants completed three experimental trials on the following separate days: exercise in the heat (36°C), exercise at neutral temperature (24°C), and exercise in the cold (12°C). The exercise trials consisted of pedaling exercises for 30 min at 65% of maximal oxygen uptake (VO_2max). Blood samples were collected repeatedly to determine plasma ghrelin, peptide YY (PYY) and other hormonal concentrations. Subjective feelings of hunger and tympanic temperature were also monitored.

Results

Tympanic temperature was significantly higher in the 36°C trial than that of the other two trials (P < 0.05). The subjective feelings of hunger in the 36°C and 24°C trials were significantly lower than those in the 12°C trial (P < 0.05). Plasma ghrelin concentration decreased significantly with exercise in all conditions (P < 0.05), and the responses were not significantly different among the three conditions. Plasma PYY concentration increased significantly after the exercise in the 24°C trial only (P < 0.05), with no significant difference among the three trials.

Conclusions

These results suggest that exposure to hot or cold temperatures during exercise did not affect exercise-induced plasma ghrelin and PYY responses. However, the exercise-induced reduction of subjective hunger was significantly attenuated in a cold environment.     

The influence of environmental enrichment on Chinese visitor behavior

Welfare improvements for nonhuman animals should aim to satisfy the needs of visitors as well as those of the animals. Little research has been conducted, however, and existing work is confined to zoos in developed countries. This article reports the behavioral responses of Chinese visitors to environmental enrichment improvements in a zoo enclosure. Visit, viewing, and stopping behaviors significantly increased at the transformed exhibit, indicating that it provoked greater visitor interest. Furthermore, increased intragroup behaviors suggested that the exhibit probably motivated visitors to interact socially. The positive impact of the exhibit changes supports the enrichment efforts taking place in zoos around the world. The changes also provide encouragement for zoos in developing countries such as China because greater visitor interest provides a strong argument and an incentive for improving welfare standards.