An Assessment of Bacterial Populations in a Static Windrow Compost Pile

ABSTRACT

Many companies, restaurants, colleges, as well as individual homeowners, have initiated green marketing campaigns, and the composting of food and yard wastes has become commonplace. Thus, it is essential to obtain a more complete understanding of the microbial populations present in such composting processes. The focus of this study was to identify bacterial populations in a static windrow compost pile initiated on a college campus containing food trim and tree debris. Given that the compost pile was initiated during the winter it was uniquely characterized by a pre-mesophilic stage in addition to the characteristic mesophilic, thermophilic, and cooling/maturation stages. Bacteria were cultured from each stage and were identified by sequencing the 16S rRNA gene. Dominating the numbers throughout the study were bacteria within the Bacillus and Bacillus-like genera. Actinobacteria were found primarily within the pre-mesophilic stage. The mesophilic and beginning thermophilic stages displayed the most diversity, characterized by several different genera within the Proteobacteria phylum. In contrast, during the late thermophilic stage, only bacteria within the Bacillus and Brevibacillus genera were cultured. Overall, 49 different species within 27 different genera, 13 families, and 4 phyla, were identified and several genera that have not been commonly associated with household compost. Thus, this study supports a role for the continuation of culture-dependent studies to more completely define the bacterial flora involved in various composting processes.     

A metapopulation perspective for salmon and other anadromous fish

Salmonids are an important component of biodiversity, culture and economy in several regions, particularly the North Pacific Rim. Given this importance, they have been intensively studied for about a century, and the pioneering scientists recognized the critical link between population structure and conservation. Spatial structure is indeed of prime importance for salmon conservation and management. At first glance, the essence of the metapopulation concept, i.e. a population of populations, widely used on other organisms like butterflies, seems to be particularly relevant to salmon, and more generally to anadromous fish. Nevertheless, the concept is rarely used, and barely tested. Here, we present a metapopulation perspective for anadromous fish, assessing in terms of processes rather than of patterns the set of necessary conditions for metapopulation dynamics to exist. Salmon, and particularly sockeye salmon in Alaska, are used as an illustrative case study. A review of life history traits indicates that the three basic conditions are likely to be fulfilled by anadromous salmon: (i) the spawning habitat is discrete and populations are spatially separated by unsuitable habitat; (ii) some asynchrony is present in the dynamics of more or less distant populations and (iii) dispersal links populations because some salmon stray from their natal population. The implications of some peculiarities of salmon life history traits, unusual in classical metapopulations, are also discussed. Deeper understanding of the population structure of anadromous fish will be advanced by future studies on specific topics: (i) criteria must be defined for the delineation of suitable habitats that are based on features of the biotope and not on the presence of fish; (ii) the collection of long‐term data and the development of improved methods to determine age structure are essential for correctly estimating levels of asynchrony between populations and (iii) several key aspects of dispersal are still poorly understood and need to be examined in detail: the spatial and temporal scales of dispersal movements, the origin and destination populations instead of simple straying rates, and the relative reproductive success of immigrants and residents.     

Stormwater runoff from highways

Water, Air, & Soil Pollution - During four rain events, stormwater runoff samples from Interstate Highway 95 in Rhode Island were collected and analyzed for petroleum hydrocarbons, 14...     

Functional MRI activity in the thalamus and occipital cortex of anesthetized dogs induced by monocular and binocular stimulation.

The neuroanatomy of the mammalian visual system has received considerable attention through electrophysiological study of cats and non-human primates, and through neuroimaging of humans. Canine neuroanatomy, however, has received much less attention, limiting our understanding of canine vision and visual pathways. As an early step in applying blood oxygenation level dependant (BOLD) functional magnetic resonance imaging (fMRI) for veterinary use, we compared visual activity in the thalamus and occipital cortex of anesthetized dogs presented with binocular and monocular visual stimuli. Activity in the left and right thalamus and occipital cortex during monocular stimulation was also compared. Six beagles were presented with a vertical grating visual stimulus and scanned at 4 Tesla. Each dog was scanned twice under each of 3 anesthetic protocols (isoflurane, propofol, and fentanyl/midazolam). We found: 1) significant BOLD activation in the lateral geniculate nucleus (LGN) of the thalamus and the occipital cortex; 2) a significantly larger area of activation in the LGN during monocular stimulation than during binocular stimulation; and 3) that activity in the hemisphere contralateral to the stimulus was not significantly greater than that ipsilateral to it.     

Tooth size and skin thickness in mature sockeye salmon: evidence for habitat constraints and variable investment between the sexes

Abstract –  Pacific salmon develop many sexually dimorphic features at maturity, and the extent of development varies among populations. In this study, we compared a suite of traits including body length, body depth, jaw length, tooth size and skin mass in male and female sockeye salmon breeding in beach and creek habitats. Both tooth size and skin mass varied positively with body length. Within each of the breeding habitats, males had longer teeth than females, and within each sex, beach spawners had longer teeth than creek spawners. Males also had heavier skin than females in each habitat but, unlike the case with tooth size, creek spawners showed a much stronger relationship between skin mass and body length than did beach spawners. Tooth length was positively related to jaw length and skin mass among individuals within a given sex and habitat. Taken together, these results suggested that variation in tooth size parallels variation in other sexually dimorphic traits. Males and beach spawners tend to exhibit large trait values relative to females and creek spawners, and 'well-endowed' individuals displayed high values of all traits rather than a trade-off as might occur if investment in one trait compromised investment in others. However, the finding that creek fish tended to have thicker skin for a given body length than did beach fish suggested that factors other than merely defense against conspecifics during battle, such as abrasion and desiccation resistance in small streams, may influence the evolution of skin mass in mature sockeye salmon.     

Bicarbonate solutions control powdery mildew (Leveillula taurica) on sweet red pepper and reduce the development of postharvest fruit rotting

Disease severity of powdery mildew (causal agentLeveillula taurica (Lév.) Arn.) on pepper (Capsicum annuum), defoliation and fruit sunscald rating were significantly reduced (P=0.05) by foliar applications of sodium or potassium bicarbonate solutions, compared with water or penconazole (Ophir). Preharvest application of bicarbonate solutions significantly reduced (P=0.05) postharvest decay development on sweet red pepper fruits.     

Temperature sex reversal implies sex gene dosage in a reptile

Sex in reptiles is determined by genes on sex chromosomes or by incubation temperature. Previously these two modes were thought to be distinct, yet we show that high incubation temperatures reverse genotypic males (ZZ) to phenotypic females in a lizard with ZZ and ZW sex chromosomes. Thus, the W chromosome is not necessary for female differentiation. Sex determination is probably via a dosage-sensitive male-determining gene on the Z chromosome that is inactivated by extreme temperatures. Our data invite a novel hypothesis for the evolution of temperature-dependent sex determination (TSD) and suggest that sex chromosomes may exist in many TSD reptiles.