Anaerobic degradation of papermill sludge in a two-phase digester containing rumen microorganisms and colonized polyurethane foam

Summary The use of reticulated polyurethane foam as a support material for the immobilization of methanogenic associations and its application to the anaerobic treatment of fine particulate solid wastes was investigated. The colonization of polyurethane support particles in a continuous upflow reactor fed on a mixture of acetate, propionate and butyrate, was both rapid and dense. The combination of rumen microorganisms and colonized support particles in a two-phase digester resulted in an efficient anaerobic decomposition of papermill sludge.     

Effects of intracranial prolactin administration on maintenance of incubation readiness, ingestive behavior, and gonadal condition in ring doves

Systemic administration of prolactin (PRL) reportedly maintains readiness to sit on eggs, increases body weights and liver weights, and reduces gonadal and reproductive tract tissue weights in male and female ring doves. To determine if these effects are mediated by PRL-induced changes in the central nervous system, ring doves were isolated from their mates, nests, and eggs on Day 4 of incubation and given twice-daily intracerebroventricular injections of PRL (1 microgram, 0.031 IU) or saline vehicle (2 microliter) during the next 10 days. Food and water consumption were monitored daily during treatment and tests for incubation behavior and observation of organ weight changes were conducted at the end of the period. The incidence of incubation behavior in the PRL-treated group was not significantly different from that in the control group and was significantly lower than that reported in a previous study following subcutaneous PRL injections. However, gonadal and reproductive tract tissue weights were markedly reduced and food and water consumption were significantly elevated in PRL-treated birds. Body weights and liver weights were also increased following PRL administration. In contrast, crop sac weight did not increase in the PRL treated birds, thereby indicating that the effects of icv prolactin treatment were not mediated by increased plasma PRL levels and peripheral target organ stimulation. These results suggest that PRL can act directly on the brain to inhibit gonadotropin release and to stimulate ingestive behavior but central effects of PRL alone are not sufficient to maintain incubation readiness.     

Effect of parental feeding activity on squab-induced crop sac growth in ring doves (Streptopelia risoria)

Effects of parental regurgitation feeding activity on crop sac development were studied in mate-separated male and female ring doves given 2 hr of daily exposure to food-deprived or recently fed squabs, for 4 consecutive days during the early posthatching period of the breeding cycle. In both sexes, food-deprived squabs stimulated more squab-directed activity, more parental regurgitation feeding activity, and greater crop sac development than recently fed young. Crop sac weights of males in both groups tended to be positively correlated with one or more parental activities. Correlations obtained in males exposed to food-deprived young further suggested that tactile stimuli associated with regurgitation behavior may promote crop sac development. In contrast to males, crop sac weights of females in both groups were not highly correlated with any type of contact-related parental activity or group of activities. These results, together with previous findings, suggest that nontactile stimuli from young played some role in mediating female crop sac weight differences in the two exposure conditions.     

Facilitation of parental behavior in ring doves by systemic or intracranial injections of prolactin

Systemic administration of ovine prolactin (PRL) has been previously reported to stimulate parental feeding behavior toward 7-day-old foster squabs by nonbreeding ring doves with previous breeding experience. The first of the present experiments reexamined this claim in experienced, nonbreeding birds given test squabs of different ages. Each visually isolated male and female dove was given twice-daily subcutaneous injections of ovine PRL or vehicle for 7 days and then tested for parental responses toward a single 1-3, 6-8, or 11- to 13-day-old foster squab. Prolactin significantly increased the incidence or frequency of parental regurgitation-feeding episodes in tests with all three squab age groups and, in addition, increased the incidence of parental feeding invitations (squab-oriented bill openings) in tests with 6- to 8-day-old squabs. A second study explored the degree to which PRL can act directly on the central nervous system to facilitate parental activity in the absence of peripheral cues generated from PRL-induced changes in other target organs, such as those associated with crop sac growth and distension. In this experiment, 6- to 8-day-old test squabs were used to determine if parental behavior is enhanced by twice-daily intracerebroventricular (ICV) injections of PRL in doses below those required to stimulate peripheral target organs. Injection schedules and behavior testing procedures were the same as those used in Experiment 1. However, half of the ICV PRL-treated and ICV vehicle-treated birds were food deprived for 16 hr before and during the test in order to control for PRL-induced hyperphagia and resulting crop sac distension, which could confound the results by generating peripheral stimuli conductive to the display of regurgitation-feeding behavior. Intracranial injections of prolactin significantly increased the incidence of feeding behavior, parental feeding invitations, and crouching or sitting in the nest in food-deprived doves but not in freely fed animals. Empty crop sac weights of freely fed and food-deprived PRL-treated birds were not increased above control values, thus indicating that ICV PRL treatment did not result in significant stimulation of peripheral target organs. These results demonstrate a facilitative action of PRL on regurgitation-feeding responses and associated parental behaviors that is not restricted to squabs of one particular age range. They also indicate that PRL is capable of acting directly on the brain to promote these activities in the absence of PRL-induced changes in the crop sac and other peripheral target organs.     

Azalea growth in response to azalea lace bug (Heteroptera: Tingidae) feeding

The effects of azalea lace bug, Stephanitis pyrioides (Scott), feeding injury on azalea growth and development were investigated using 'Girard's Rose' azaleas during a 2-yr field study in Georgia Low, medium, and high injury treatments, which corresponded to 6, 8, and 14% maximum canopy area injury, were compared with control azaleas that received no lace bug infestation. Flower number, whole-shrub leaf and stem dry mass, and dry mass and size of new growth tissues were unaffected by treatments. In contrast, growth index measurements, a general measure of variability frequently used for horticultural differentiation, showed significant reductions for all treatments in comparison to control azaleas after 20 wk. Though not directly quantified, this apparent discrepancy may be explained as an artifact of lace bug feeding-induced leaf abscission. Growth index measurements had considerable variability and may not be the most reliable measurement of size. In July 1998, plant canopy densities among azaleas maintained in the high injury treatments were approximately 15% less full than the canopies of control shrubs. Predaceous insects had a significant negative association with azalea lace bug number during the 2-yr study. Flower and new tissue production, measured destructively during two growing seasons, revealed azalea tolerance to 14% of maximum canopy area lace bug feeding-injury levels.     

The Roles of Stimuli from Young, Previous Breeding Experience, and Prolactin in Regulating Parental Behavior in Ring Doves (Streptopelia risoria)

In addition to stimulating crop "milk" formation in ring doves, prolactin (PRL) may promote the parental regurgitation behavior that transfers this "milk" to the young at the time of hatching. Although earlier studies suggest that previous breeding experience is an important modulator of PRL-induced parental regurgitation behavior in ring doves, the ways in which experience, hormones, and stimuli from young interact to promote parental behavior have not been well characterized in this species. In the first study, untreated, nonbreeding female doves with and without previous breeding experience were given 10 daily parental behavior tests (2 h/day) with a hungry 5- to 10-day-old foster squab. Experienced females exhibited a higher incidence of regurgitation behavior, defensive behavior, and crouching or sitting in the nest than did inexperienced females. In a second study, nonbreeding females were given 10 daily tests for parental behavior while they received sc injections of ovine PRL or vehicle. Prolactin reduced squab-directed aggression and increased the incidence of regurgitation feeding behavior of foster squabs in both experienced and inexperienced females. However, the average number of regurgitation feeding acts displayed by those PRL-treated females that showed the behavior was over eight times higher in experienced females than in inexperienced females. Previous experience also enhanced the stimulatory effects of PRL on defensive behavior and crouching or sitting in the nest. The parental behavior exhibited by nonbreeding, PRL-treated experienced females was qualitatively and quantitatively similar to that observed in normally breeding females during a single test with their own hungry 5- to 10-day-old squabs. These findings indicate that PRL and previous breeding experience both enhance the parental responsiveness of nonbreeding female doves and that under optimal hormonal, experiential, and squab exposure conditions, nonbreeding doves exhibit levels of parental activity that rival those of normally breeding parents.     

Identification of growth-hormone- and prolactin-containing neurons within the avian brain

Prolactin (PRL)- and growth-hormone (GH)-containing perikarya and fibers independent of the anterior pituitary gland have been reported to exist in the central nervous system of several mammalian species. The specific distributions of PRL- or GH-like neurons in the avian forebrain and midbrain, however, have not been reported. The objective of the study was to identify GH- and PRL-containing neurons in the hypothalamus and a few extrahypothalamic areas of two avian species. Brain and peripheral blood samples were collected from laying and broody turkey hens and ring doves. Broody turkey hens and doves had significantly higher plasma PRL concentrations compared with laying hens. Coronal brain sections were prepared and immunostained using anti-turkey GH and anti-chicken synthetic PRL antibodies. In turkey hens, the most dense GH-immunoreactive (ir) perikarya and fibers were found in hippocampus (Hp), periventricular hypothalamic nucleus, paraventricular nucleus, inferior hypothalamic nucleus, infundibular hypothalamic nucleus, medial and lateral septal area, and external zone of the median eminence (ME). In the ring dove, a similar pattern of distribution of GH-ir neurons was noticed at the brain sites listed above except that GH-ir fibers and granules were found only in the internal zone of ME and not in the external zone. In both turkeys and doves, the most immunoreactive PRL-ir perikarya and fibers were found in the medial and lateral septal area, Hp (turkey only), and bed nucleus of the stria terminalis pars magnocellularis. There were no apparent differences in the staining pattern of GH- or PRL-ir neurons between the laying and broody states in either species. However, the presence of GH-ir- and PRL-ir perikarya and fibers in several hypothalamic nuclei indicates that GH and PRL may influence parental behavior, food intake, autonomic nervous system function, and/or reproduction.     

Greenhouse and field evaluations of transgenic canola against diamondback moth, shape Plutella xylostella, and corn earworm, shape Helicoverpa zea

Canola (Brassica napus L.) cultivars Oscar and Westar, engineered with a Bacillus thuringiensis (Bt) cryIA(c) gene, were evaluated for resistance to lepidopterous pests, diamondback moth, Plutella xylostella L. (Plutellidae) and corn earworm, Helicoverpa zea (Boddie) (Noctuidae) in greenhouse and field conditions. In greenhouse preference assays conducted at vegetative and flowering plant stages, transgenic plants recorded very low levels of damage. A 100% diamondback moth mortality and 90% corn earworm mortality were obtained on transgenic plants in greenhouse antibiosis assays. The surviving corn earworm larvae on transgenic plants had reduced head capsule width and body weight. Mortality of diamondback moth and corn earworm were 100% and 95%, respectively, at different growth stages (seedling, vegetative, bolting, and flowering) on the transgenic plants in greenhouse tests. In field tests conducted during 1995–1997, plots were artificially infested with neonates of diamondback moth or corn earworm or left for natural infestation. Transgenic plants in all the treatments were highly resistant to diamondback moth and corn earworm larvae and had very low levels of defoliation. Plots infested with diamondback moth larvae had greater damage in both seasons as compared with corn earworm infested plots and plots under natural infestation. After exposure to defoliators, transgenic plants usually had higher final plant stand and produced more pods and seeds than non-transgenic plants. Diamondback moth injury caused the most pronounced difference in plant stand and pod and seed number between transgenic and non-transgenic plants. Our results suggest that transgenic canola could be used for effective management of diamondback moth and corn earworm on canola.     

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis

Background and methods

Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.

Results

We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 10⁵ viral copies/ml in nasal lavage and 1.88 × 10⁵ viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.

Conclusion

HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely.     

Damage loss assessment and control of the cereal leaf beetle (Coleoptera: Chrysomelidae) in winter wheat

Cereal leaf beetle, Oulema melanopus (L.), invaded northern Alabama and Georgia more than a decade ago and since has become an economic pest of winter wheat and other cereal crops in the southeastern United States. A series of trials was conducted beginning in 1995 to determine optimal rate and timing of applications of selected foliar insecticides for managing cereal leaf beetle in soft red winter wheat. These trials, cage studies with larvae, and a manual defoliation experiment were used to provide information on cereal leafbeetle yield loss relationships and to develop economic decision rules for cereal leaf beetle in soft red winter wheat. Malathion, methomyl, carbaryl, and spinosad effectively controlled larval infestations when treatments were applied after most eggs had hatched. Encapsulated endotoxin of Bacillus thuringiensis, methyl parathion, and disulfoton applied at the lowest labeled rates were not effective treatments. Organophosphate insecticides generally were not effective when applied before most eggs had hatched. The most effective treatments were the low rates of lambda cyhalothrin when applied early while adults were still laying eggs and before or near 50% egg hatch. These early applications applied at or before spike emergence virtually eliminated cereal leaf beetle injury. The manual defoliation study demonstrated that defoliation before spike emergence has greater impact on grain yield and yield components than defoliation after spike emergence. Furthermore, flag leaf defoliation causes more damage than injury to lower leaves. Grain test weight and kernel weight were not affected by larval injury in most trials. Regression of larval numbers and yield losses calculated a yield loss of 12.65% or 459 kg/ha per larva per stem, which at current application costs suggested an economic threshold of 0.4 larvae per stem during the spike emergence to anthesis stages.