Serratia entomophila, the causative agent of amber disease, is an endemic bacterium used for the biocontrol of New Zealand grass grub larvae. Although the available biopesticide is effective, its use is limited to areas where sub-surface application is feasible, and is also impacted by soil conditions such as moisture levels and osmolarity. The aim of this study was to elucidate the responses of S. entomophila to osmotic and desiccation stresses in relation to challenges encountered during production, storage and soil application, with the goal of developing a more robust and versatile biocontrol agent. RpoS is a key factor in the stress response of many enteric bacteria. In order to dissociate the effect of RpoS from subsequent cellular stress studies, an rpoS mutant was constructed by site-directed mutagenesis. Assessment of the rpoS mutant showed that RpoS was not implicated in NaC1 or desiccation tolerance of S. entomophila. The rpoS mutant was instead found to have enhanced salt tolerance and could be distinguished from the wild-type by the ability to ferment arabinose, a phenotype that was confirmed through complementation. Complete abolition of the amber disease process was observed using an rpoS strain also missing the Sep virulence genes, suggesting that RpoS is a regulator of the S. entomophila anti-feeding prophage (Afp). These findings indicate a subtle interplay between NaC1 tolerance, virulence and RpoS-mediated regulation of amber disease in S. entomophila. A transposon mutagenesis screen was carried out to identify genes associated with NaC1 tolerance in S. entomophila. Fourteen mutants displaying NaC1 sensitivity were identified, two of which had mutations in genes with potential implications for the formulation of the bacterium as a biocontrol agent. The gene leuO that encodes a LysR-family transcriptional regulator was found to be essential for S. entomophila NaC1 tolerance. The toxicity of increased cellular LeuO from an over-expression vector led to the investigation of the effects of leuO mutation on the proteome. Multiple protein changes observed by two-dimensional gel analysis suggested that LeuO may be a global regulator in S. entomophila, as has been hypothesised for Salmonella species. A second NaC1-sensitive mutant contained an insertion in afp15, the product of which is thought to be involved in assembly of the Afp. As well as being sensitive to NaC1, the afp15 mutant was unable to induce the anti-feeding component of amber disease, again highlighting the link between stress tolerance and virulence in S. entomophila. This study also determined that pre-exposure to NaC1 in conjunction with the provision of exogenous glycine betaine significantly enhanced the survival of S. entomophila either in a desiccated state or after application to soil, regardless of the soil moisture content. The implication of this finding on the future formulation of S. entomophila led to investigation of the underlying genetic mechanisms involved in glycine betaine synthesis and NaC1 tolerance. The genes involved in glycine betaine biosynthesis from choline were identified through genomic comparison, degenerate PCR and primer walking. A 6.5 kb region was sequenced and found to contain four genes with homology and similar chromosomal arrangement to the E. coli bet genes (betTIBA). The S. entomophila betIBA genes comprised an operon, flanked by the divergently-transcribed betT gene whose product is responsible for choline transport. To ascertain the relative transcription levels of components of the bet operon, quantitative RT-PCR was performed. Results of qRT-PCR showed that choline in conjunction with NaC1 induced the greatest levels of bet gene transcription, and that levels of the betA transcript were significantly lower than those of the other bet genes. Examination of the betA 5� non-coding region identified a previously undetected hairpin region, possibly accounting for the observed decrease in betA transcript levels. The findings of this study have significantly advanced our understanding of how S. entomophiia responds to stress, and will contribute to the development of formulation strategies for the production of a robust product capable of application to pasture by a range of teclmiques. In addition, there is significant potential to utilise these findings in the development of other bacterial inocula for a range of biotechnological applications.

Serratia entomophila, the causative agent of amber disease, is an endemic bacterium used for the biocontrol of New Zealand grass grub larvae. Although the available biopesticide is effective, its use is limited to areas where sub-surface application is feasible, and is also impacted by soil conditions such as moisture levels and osmolarity. The aim of this study was to elucidate the responses of S. entomophila to osmotic and desiccation stresses in relation to challenges encountered during production, storage and soil application, with the goal of developing a more robust and versatile biocontrol agent. RpoS is a key factor in the stress response of many enteric bacteria. In order to dissociate the effect of RpoS from subsequent cellular stress studies, an rpoS mutant was constructed by site-directed mutagenesis. Assessment of the rpoS mutant showed that RpoS was not implicated in NaC1 or desiccation tolerance of S. entomophila. The rpoS mutant was instead found to have enhanced salt tolerance and could be distinguished from the wild-type by the ability to ferment arabinose, a phenotype that was confirmed through complementation. Complete abolition of the amber disease process was observed using an rpoS strain also missing the Sep virulence genes, suggesting that RpoS is a regulator of the S. entomophila anti-feeding prophage (Afp). These findings indicate a subtle interplay between NaC1 tolerance, virulence and RpoS-mediated regulation of amber disease in S. entomophila. A transposon mutagenesis screen was carried out to identify genes associated with NaC1 tolerance in S. entomophila. Fourteen mutants displaying NaC1 sensitivity were identified, two of which had mutations in genes with potential implications for the formulation of the bacterium as a biocontrol agent. The gene leuO that encodes a LysR-family transcriptional regulator was found to be essential for S. entomophila NaC1 tolerance. The toxicity of increased cellular LeuO from an over-expression vector led to the investigation of the effects of leuO mutation on the proteome. Multiple protein changes observed by two-dimensional gel analysis suggested that LeuO may be a global regulator in S. entomophila, as has been hypothesised for Salmonella species. A second NaC1-sensitive mutant contained an insertion in afp15, the product of which is thought to be involved in assembly of the Afp. As well as being sensitive to NaC1, the afp15 mutant was unable to induce the anti-feeding component of amber disease, again highlighting the link between stress tolerance and virulence in S. entomophila. This study also determined that pre-exposure to NaC1 in conjunction with the provision of exogenous glycine betaine significantly enhanced the survival of S. entomophila either in a desiccated state or after application to soil, regardless of the soil moisture content. The implication of this finding on the future formulation of S. entomophila led to investigation of the underlying genetic mechanisms involved in glycine betaine synthesis and NaC1 tolerance. The genes involved in glycine betaine biosynthesis from choline were identified through genomic comparison, degenerate PCR and primer walking. A 6.5 kb region was sequenced and found to contain four genes with homology and similar chromosomal arrangement to the E. coli bet genes (betTIBA). The S. entomophila betIBA genes comprised an operon, flanked by the divergently-transcribed betT gene whose product is responsible for choline transport. To ascertain the relative transcription levels of components of the bet operon, quantitative RT-PCR was performed. Results of qRT-PCR showed that choline in conjunction with NaC1 induced the greatest levels of bet gene transcription, and that levels of the betA transcript were significantly lower than those of the other bet genes. Examination of the betA 5� non-coding region identified a previously undetected hairpin region, possibly accounting for the observed decrease in betA transcript levels. The findings of this study have significantly advanced our understanding of how S. entomophiia responds to stress, and will contribute to the development of formulation strategies for the production of a robust product capable of application to pasture by a range of teclmiques. In addition, there is significant potential to utilise these findings in the development of other bacterial inocula for a range of biotechnological applications.

Entomopathogenic nematodes (EPN) (Heterorhabditis bacteriophora and H. megidis) and entomopathogenic fungi (EPF) (Metarhizium anisopliae and Beauveria bassiana) were evaluated for efficacy against masked chafer white grub, Cyclocephala spp., under laboratory and greenhouse conditions, as well as their efficacy against various grub stages in the field.  Under both laboratory and greenhouse conditions, additive interactions were found between EPN and EPF in their combined application against Cyclocephala spp., except a few observations that showed antagonism or synergism.  Significantly greater control occurred from the combination of a nematode and a fungus compared with a fungus alone, but not compared with a nematode alone.  The combined effect did not differ significantly for nematode and fungi applied simultaneously or at different times.  EPF had no significant impact on EPN infection and production of infective juveniles (IJs) in grub carcasses.  Nematodes alone or in combination with fungi were comparable to the insecticide Merit 75 WP (imidacloprid) against 3rd instar Cyclocephala spp in the greenhouse. Efficacy of EPF and EPN varied dramatically between field sites and conditions; EPN and EPF applied alone or in combination were less effective than Merit 75 WP in >50% field trials, but some EPN + EPF treatments were more effective than the insecticide in reducing grub numbers.  EPN and EPF showed better potential than insecticides for providing extended control of white grubs in the subsequent generation.  In addition, the sub-lethal effects of EPF on southern masked chafer, C. lurida, were investigated.  Neither M. anisopliae nor B. bassiana had a sub-lethal effect on grub weight gain, adult longevity, oviposition, pupation and eclosion.  Finally, interaction between H. bacteriophora and M. anisopliae was examined to determine the potential of the nematode in improving fungal distribution in soil.  H. bacteriophora enhanced fungal distribution in sandy loam soil without grass thatch, but not in sandy soil with thatch.  In both soil types, soil depths significantly affected nematode and fungal distribution. In water profile, M. anisopliae conidia germinated hyphae that attached to sheath of H. bacteriophora IJs, which molted to detach from the fungus.  IJs mortality and virulence were not affected by the presence of M. anisopliae. / Ph. D.

Darbo tikslas – nustatyti maisto medžiagų kiekius išmatose, nustatyti pasisavinimo lygį vokiečių aviganių veislės suaugusių šunų (kalių ir patinų) organizme; įvertinti įtaką kraujo biocheminiams ir morfologiniams rodikliams; įvertinti išskiriamų išmatų konsistenciją. Mokslinio darbo naujumas –mūsų šalyje pirmą kartą atliktas virškinamumo-balansinis bandymas su suaugusiomis vokiečių aviganių veislės kalėmis ir patinais ir įvertintas ceolito poveikis sausosios medžiagos, organinės medžiagos, žalių baltymų, žalių riebalų, žalios ląstelienos, žalių pelenų ir neazotinių ekstraktinių medžiagų pasisavinamumui ramybės, kergimo, šuningumo, laktacijos laikotarpiuose. Praktinė darbo reikšmė – panaudojant naujus priedus gaminti ėdalus šunims bei katėms, kad galima būtų optimizuoti virškinimo ir rezorbcijos procesus šių gyvūnų organizme. Remiantis atliktų bandymų duomenimis nustatytas klinoptilolito teigiamas poveikis kai kurių maisto medžiagų pasisavinamumui gyvūnų organizme, sveikatingumui, o taip pat mažesnis taršos laipsnis aplinkai. Šunų šėrimui šiuo metu yra gaminama daugybė skirtingų ėdalų, panaudojant įvairius papildus bei priedus. Sudaromi pilnai subalansuoti ėdalų receptai, kurių sudėtyje pateikiami įvairiausi augaliniai ir gyvūniniai komponentai. Ėdalams gaminti panaudojami tik geros kokybės produktai, kurie lengvai gyvūno organizme suskaidomi, aukštame lygyje pasisavinami ir nekenkia jo sveikatingumui. Pastaraisiais metais susirūpinimas ėdalų sauga vis didėja, kokybė ir sauga... [toliau žr. visą tekstą] / Aim of the study – to determine the volumes of nutrients in the faeces and to identify the level of digestion in German shepherd breed dog system (males and females); to assess the impact to the blood biochemical and morphological indexes; to evaluate the consistency of the faeces secretion. The novelty of scientific study – for the first time in our country a balance experiment of digestion was performed with grown up German shepherd breed female and male dogs and the influence of zeolite to the digestion of dry matter, organic matter, raw proteins, raw fat, raw fiber, raw ash and non-nitrogenous extractive materials during calm, mating, breeding and lactation periods. Practical significance of the scientific study – to produce dog and cat food by using new supplements in order of optimizing the digestion and absorption processes in these animals organisms. The positive effect of clynoptilolite to digestion of some nutrients, wellbeing and lower emission levels were identified by using the data of the performed experiments. Currently there is a vast range of mash manufactured by using various supplements and additives. Fully balanced mash recipes are composed, which contains various herbal and animal components. Only good quality products, which are easily digestable, have high level of absorption and doesn‘t have a negative impact to the health of an animal are used. The safety concerns of the mash are on the rise in the latter year and are becoming more relevant in the... [to full text]

Digenetic trematodes are a common pest problem in aquaculture where their unappetizing appearance often reduces the marketability of food fish. Aquatic snails are intermediate hosts in the trematode lifecycle and are commonly targeted with control measures to prevent the crop fish from becoming infected. I evaluated several chemical and biological snail control strategies as alternatives to the potentially invasive black carp. Copper sulfate, hydrated lime slurry, and several fish and decapod species were tested for effectiveness against physid (Physa spp.) and planorbid (Helisoma spp.) snails in laboratory aquaria trials. Hydrated lime demonstrated effectiveness with the least potential to be toxic to cultured fish in regional application. Hybrid sunfish (redear × green sunfish) consumed large quantities of both snails in ad libitum feedings. The most effective biological (redear × green sunfish) and chemical (hydrated lime) control methods identified in the laboratory were evaluated further in research ponds. Hydrated lime applications of 9.07 kg over 9.14 m2 were found to be effective against Helisoma spp. confined to enclosures along the pond shoreline; average survival was 2%. When stocked in aquaculture ponds, hybrid redear sunfish did not significantly influence snail capture rates; however ponds stocked with redear sunfish experienced a gradual decrease in snail populations throughout the 2008 growing season. Hydrated lime and a combination of redear sunfish and hybrid redear sunfish were evaluated separately and in tandem as a combined chemical/biological treatment in the 2009 growing season. Evaluation occurred under mock production conditions in which hybrid striped bass were raised in the research ponds to determine snail treatment effects on trematode abundance. Ponds stocked with sunfish at 494 fish/ha had snail densities significantly (P ≤ 0.05) lower than control ponds after two months. Ponds treated with hydrated lime at 31.7 kg/31.5 m of shoreline in a 1 m swath experienced 99% estimated reductions in snail densities following application, but snail populations rebounded to previous levels within two months. The mean snail density in ponds treated with both hydrated lime and sunfish was significantly lower than control one month post treatment; this mean rebounded slightly by the conclusion of the trial, but not as much as in the chemical treatment group. Hybrid striped bass examined thoroughly for trematodes revealed a positive relationship between trematode abundance in fish and increasing Helisoma densities. This relationship was most apparent when estimates of snail density from only the beginning of the trial were used. Based on these results, it appears that a nearly complete reduction of Helisoma, particularly at the time of stocking fingerlings, is necessary to avoid a high abundance of trematodes in cultured fish. To this end, an early-season application of molluscicides followed closely by stocking of predator sunfish has potential to achieve a uniformly low density of snails throughout the growing season.

Buddhist tantric practitioners embrace the liminal status of the human body to manifest divine identity. In piercing to the pith of human embodiment, the tantric practitioner reconfigures the shape and contours of his/her reality. This article investigates the evolution of one particular technique for piercing to the pith of the body on Tibetan soil, a ritual practice known as body mandala [lus dkyil Skt. deha-man. d. ala]. In particular, it uncovers a significant shift of emphasis in the application of the Guhyasamaja body mandala practice initiated by champions of the emerging Gandenpa [Dga' ldan pa] or Gelukpa [Dge lugs pa] tradition of Tibetan Buddhism, Tsongkhapa (1357-1419) and Mkhas grub rje (1385-1438). This article reveals some of the radical implications of ritual exegesis, ranging from the socioreligious aspects of securing prestige for a tradition to the ultimate soteriological goals of modifying the boundaries between life and death and ordinary and enlightened embodiment.

No description available.

Root-feeding insects can have top-down influence on vegetative composition and ecosystem processes; however, they may respond to bottom-up factors such as soil resources, site productivity, and disturbance.  My research addressed the following questions: (1) Do disturbance (fire), vegetative composition, soil resources, and fine root standing mass influence the structure of root-feeding insect assemblages? (2) What types of roots do root-feeding insects eat, and do they forage selectively?  (3) Do root-feeding insects influence fine root productivity?  To address these questions, I studied root-feeding insect assemblages in longleaf pine wiregrass (Pinus palustris-Aristida stricta) ecosystems of southwestern Georgia, U.S.A.  On a random basis, study sites were burned at least every other year (B), or left unburned (UB) for about 9 years.  Fine root productivity and root-feeding insect abundances were sampled repeatedly across 54 random plots in UB and B sites.  In Chapter 2, I characterized spatial and temporal patterns of root-feeding insect abundance, understory plant composition, soil resource availability, and fine root standing mass within each plot.  Insect population densities were low overall, but abundance, patchiness, and diversity were greater in UB sites.  Abundance patterns were significantly related to vegetative composition.  In Chapter 3, I quantified the diet of root-feeding insects by measuring the natural abundance of carbon (C) and nitrogen (N) stable isotopes in insects and fine roots.  Using 13C abundance, I examined the contribution of warm season grass roots to insect diet, relative to the proportion of warm season grass roots within adjacent root standing crop samples; 15N abundance was used to detect omnivory.  Overall, insects appeared to be non-selective herbivores and omnivores that may alter foraging behavior to maintain a mixed diet (i.e. reducing or increasing warm season grass consumption when its abundance was high or low, respectively).  The extent of omnivory varied within and among taxa.  In Chapter 4, I estimated the top-down influence of root-feeding insects on fine root productivity by comparison of ingrowth cores with or without an insecticide treatment.  I detected a weak positive effect of herbivores on the productivity of non-grass fine roots (< 10% of fine root productivity). / Ph. D.

Murderer, bastard, spy: Richard Savage was no stranger to scandal and controversy. And yet, for a man who lived such a varied life, little is known for certain about him. There are rumors, suggestions, and accusations, but little that can be said without debates and arguments. It certainly does not help that Savage is often marginalized in eighteenth-century scholarship as scholars seek to discover and analyze all they can about his more famous, and more upstanding, contemporaries. While Savage's relationship with Johnson is well known and discussed frequently, all that is known of his relationship with Pope is that he contributed information to Pope's Dunciad Variorum (1729) and that Pope later contributed large sums to Savage's support. Pope was the driving force behind Savage's retirement to Wales, possibly alluded to in Johnson's London (1738), as well as the chief financial contributor to this retirement plan. No serious effort has been made to connect these two important episodes in Savage's life, perhaps because no serious effort has been made to establish the extent of his involvement with the Dunciad. It may have been this connection with Pope that drew Johnson to Savage in the first place. The intent of this thesis is to clarify the nature of Savage's collaborations with Pope and the extent of his contributions to the Dunciad Variorum of 1729. The Dunciad seeks to make fun not only of Pope's critics, but of writers who write for bread, the "hack writers" of Grub Street. It was here that Pope would most likely turn to Savage for information; Savage was much better acquainted with those writers than was Pope. But Savage may have done more than simply supply Pope with gossip, and I will consider the possibility that he had a more active role in the publication of the Dunciad Variorum. / Master of Arts

No description available.