Relationship between Coefficient of Inbreeding and Parasite Burden in Endangered Gazelles

Abstract: We studied the effects of inbreeding depression on parasite infection in three species of endangered gazelles: Gazella cuvieri , G. dama, and G. dorcas . Coefficients of inbreeding were calculated for all individuals because complete genealogies were available. The levels of inbreeding differ both intra- and interspecifically. We collected samples of feces and determined nematode infection by counting nematode eggs in the samples. At the interspecific level, the species with the highest mean levels of inbreeding (  G. cuvieri ) had the highest levels of gastrointestinal parasites. Analyses done at the intraspecific level revealed a positive relationship between individual coefficient of inbreeding and parasite infection in G. cuvieri , but not in the species with the intermediate and lowest levels of inbreeding. Our findings suggest that high levels of inbreeding may make individuals more susceptible to parasitism, even under favorable environmental conditions, so this factor should be taken into account by those managing endangered species.     

Intranest relatedness and nestmate recognition in the meadow ant Formica pratensis (R.)

The impact of intranest relatedness on nestmate recognition was tested in a population of polydomous and monodomous nests of the mound-building ant Formica pratensis. Nestmate recognition was evaluated by testing aggression levels between 37 pairs of nests (n=206 tests). Workers from donor colonies were placed on the mounds of recipient nests to score aggressive interactions among workers. A total of 555 workers from 27 nests were genotyped using four DNA microsatellites. The genetic and spatial distances of nests were positively correlated, indicating budding and/or fissioning as spread mechanisms. Monodomous and polydomous nests did not show different aggression levels. Aggression behavior between nests was positively correlated with both spatial distance and intranest relatedness of recipient colonies, but not with genetic distance or intranest relatedness of donor colonies. Multiple regression analysis revealed a stronger effect of spatial distance than of genetics on aggression behavior in this study, indicating that the relative importance of environment and genetics can be variable in F. pratensis. Nevertheless, the positive regression between intranest relatedness of recipient colonies and aggression in the multiple analysis supports earlier results that nestmate recognition is genetically influenced in F. pratensis and further indicates that foreign label rejection most likely explains our data.     

Climate Warming and Calling Phenology of Frogs near Ithaca, New York, 1900–1999

Abstract: Because ambient temperature strongly influences reproduction in frogs, the seasonal timing of frog calling provides a sensitive index of biotic response to climate change. Over the last century, daily temperatures increased during 5 of the 8 months key to gametogenesis in frogs and toads near Ithaca, New York ( U.S.A.). Earliest dates of calling frogs recorded by Albert Hazen Wright between 1900 and 1912 near Ithaca were compared to those from the New York State Amphibian and Reptile Atlas Project for 1990–1999 for the three counties surrounding Ithaca. Four species are now calling 10–13 days earlier, two are unchanged, and none is calling later. The data suggest that climate has warmed in central New York State during this century and has resulted in earlier breeding in some amphibians—a possible first indication of biotic response to climate change in eastern North America.     

Natural Rubber-Based Pressure-Sensitive Adhesives: A Review

The purpose of this review is to describe the various aspects of pressure-sensitive adhesives prepared from natural rubber. Pressure-sensitive adhesives (PSAs) adhere instantaneously to a variety of surfaces upon application of slight pressure and can be obtained using different technologies. PSAs are materials that develop tack for low pressures and short contact times. There are number of factors affecting the adhesion property of natural rubber based pressure-sensitive adhesives. In this review, factors affecting adhesion property such as tack, peel and shear are examined in light of their relevance to adhesion in addition to measurement methods of each of the three major adhesion properties. This review paper covers the work being carried out from the last 20 years in the field of natural rubber based pressure sensitive adhesives.     

Constitutive model for municipal solid waste incorporating mechanical creep and biodegradation-induced compression

A constitutive model is proposed to describe the stress–strain behavior of municipal solid waste (MSW) under loading using the critical state soil mechanics framework. The modified cam clay model is extended to incorporate the effects of mechanical creep and time dependent biodegradation to calculate total compression under loading. Model parameters are evaluated based on one-dimensional compression and triaxial consolidated undrained test series conducted on three types of MSW: (a) fresh MSW obtained from working phase of a landfill, (b) landfilled waste retrieved from a landfill after 1.5 years of degradation, and (c) synthetic MSW with controlled composition. The model captures the stress–strain and pore water pressure response of these three types of MSW adequately. The model is useful for assessing the deformation and stability of landfills and any post-closure development structures located on landfills.     

Modeling microbiological and chemical processes in municipal solid waste bioreactor,part I: Development of a three-phase numerical model BIOKEMOD-3P

The numerical computer models that simulate municipal solid waste (MSW) bioreactor landfills have mainly two components – a biodegradation process module and a multi-phase flow module. The biodegradation model describes the chemical and microbiological processes. The models available to date include predefined solid waste biodegradation reactions and participating species. Some of these models allow changing the basic composition of solid waste. In a bioreactor landfill several processes like anaerobic and aerobic solids biodegradation, nitrogen and sulfate related processes, precipitation and dissolution of metals, and adsorption and gasification of various anthropogenic organic compounds occur simultaneously. These processes may involve reactions of several species and the available biochemical models for solid waste biodegradation do not provide users with the flexibility to simulate these processes by choice. This paper presents the development of a generalized biochemical process model BIOKEMOD-3P which can accommodate a large number of species and process reactions. This model is able to simulate bioreactor landfill operation in a completely mixed condition, when coupled with a multi-phase model it will be able to simulate a full-scale bioreactor landfill. This generalized biochemical model can simulate laboratory and pilot-scale operations in order to determine biochemical parameters important for simulation of full-scale operations.     

A mass transfer model of ammonia volatilisation from anaerobic digestate

Anaerobic digestion (AD) is becoming increasingly popular for treating organic waste. The methane produced can be burned to generate electricity and the digestate, which is high in mineral nitrogen, can be used as a fertiliser. In this paper we evaluate potential losses of ammonia via volatilisation from food waste anaerobic digestate using a closed chamber system equipped with a sulphuric acid trap. Ammonia losses represent a pollution source and, over long periods could reduce the agronomic value of the digestate. Observed ammonia losses from the experimental system were linear with time. A simple non-steady-state partitioning model was developed to represent the process. After calibration, the model was able to describe the behaviour of ammonia in the digestate and in the trap very well. The average rate of volatilisation was approximately 5.2 g N m^?2 week^?1. The model was used to extrapolate the findings of the laboratory study to a number of AD storage scenarios. The simulations highlight that open storage of digestate could result in significant losses of ammonia to the atmosphere. Losses are predicted to be relatively minor from covered facilities, particularly if depth to surface area ratio is high.     

Generating CO2-credits through landfill in situ aeration

Landfills are some of the major anthropogenic sources of methane emissions worldwide. The installation and operation of gas extraction systems for many landfills in Europe and the US, often including technical installations for energy recovery, significantly reduced these emissions during the last decades. Residual landfill gas, however, is still continuously produced after the energy recovery became economically unattractive, thus resulting in ongoing methane emissions for many years. By landfill in situ aeration these methane emissions can be widely avoided both, during the aeration process as well as in the subsequent aftercare period. Based on model calculations and online monitoring data the amount of avoided CO_2-eq. can be determined. For an in situ aerated landfill in northern Germany, acting as a case study, 83–95% (depending on the kind and quality of top cover) of the greenhouse gas emission potential could be reduced under strictly controlled conditions. Recently the United Nations Framework Convention on Climate Change (UNFCCC) has approved a new methodology on the “Avoidance of landfill gas emissions by in situ aeration of landfills” (UNFCCC, 2009). Based on this methodology landfill aeration projects might be considered for generation of Certified Emission Reductions (CERs) in the course of CDM projects. This paper contributes towards an evaluation of the potential of landfill aeration for methane emissions reduction.     

Briquetting of charcoal from sugar-cane bagasse fly ash (scbfa) as an alternative fuel

Brazil is the largest worldwide producer of alcohol and sugar from sugar-cane and has an extensive alternative program for car fuel which is unique. The objective of this work is to offer one management option of a solid residue produced by this industrial segment. The pressed sugar-cane bagasse is burned to produce steam and electricity by cogeneration. The combustion yields both bottom and fly ashes which contain high amounts of silicon oxide as a major component. Fly ash which contains a high volume (>30% by weight) of charcoal was used in this work. The ash was sieved to separate the thick charcoal from inorganic materials which are concentrated in the thinner fraction. The briquettes were hand pressed using charcoal mixed with a binder (starch) obtained from cassava flour (a tropical root). The results (density, mechanical resistance) obtained with 8% by weight of starch binder are presented here. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to characterize the ashes and the briquettes. The results show that sugar-cane bagasse fly ash (SCBFA) can be used to produce briquettes with an average density of 1.12 g cm^?3 and an average calorific value of 25,551 kJ/kg.