Evaluating mortality rates with a novel integrated framework for nonmonogamous species

The conservation of wildlife requires management based on quantitative evidence, and especially for large carnivores, unraveling cause‐specific mortalities and understanding their impact on population dynamics is crucial. Acquiring this knowledge is challenging because it is difficult to obtain robust long‐term data sets on endangered populations and, usually, data are collected through diverse sampling strategies. Integrated population models (IPMs) offer a way to integrate data generated through different processes. However, IPMs are female‐based models that cannot account for mate availability, and this feature limits their applicability to monogamous species only. We extended classical IPMs to a two‐sex framework that allows investigation of population dynamics and quantification of cause‐specific mortality rates in nonmonogamous species. We illustrated our approach by simultaneously modeling different types of data from a reintroduced, unhunted brown bear (Ursus arctos) population living in an area with a dense human population. In a population mainly driven by adult survival, we estimated that on average 11% of cubs and 61% of adults died from human‐related causes. Although the population is currently not at risk, adult survival and thus population dynamics are driven by anthropogenic mortality. Given the recent increase of human‐bear conflicts in the area, removal of individuals for management purposes and through poaching may increase, reversing the positive population growth rate. Our approach can be generalized to other species affected by cause‐specific mortality and will be useful to inform conservation decisions for other nonmonogamous species, such as most large carnivores, for which data are scarce and diverse and thus data integration is highly desirable.     

Simulating the potential for ecological restoration of dryland forests in Mexico under different disturbance regimes

Examining the potential for ecological restoration is important in areas where anthropogenic disturbance has degraded forest landscapes. However, the conditions under which restoration of degraded tropical dry forests (TDF) might be achieved in practice have not been determined in detail. In this study, we used LANDIS-II, a spatially explicit model of forest dynamics, to assess the potential for passive restoration of TDF through natural regeneration. The model was applied to two Mexican landscapes under six different disturbance regimes, focusing on the impact of fire and cattle grazing on forest cover, structure and composition. Model results identified two main findings. First, tropical dry forests are more resilient to anthropogenic disturbance than expected. Results suggested that under both a scenario of small, infrequent fires and a scenario of large, frequent fires, forest area can increase relatively rapidly. However, forest structure and composition differed markedly between these scenarios. After 400 years, the landscape becomes increasingly occupied by relatively shade-tolerant species under small, infrequent fires, but only species with both relatively high shade tolerance and high fire tolerance can thrive under conditions with large, frequent fires. Second, we demonstrated that different forms of disturbance can interact in unexpected ways. Our projections revealed that when grazing acts in combination with fire, forest cover, structure and composition vary dramatically depending on the frequency and extent of the fires. Results indicated that grazing and fire have a synergistic effect causing a reduction in forest cover greater than the sum of their individual effects. This suggests that passive landscape-scale restoration of TDF is achievable in both Mexican study areas only if grazing is reduced, and fires are carefully managed to reduce their frequency and intensity.     

Alternative low-cost process for large-scale production of Bacillus thuringiensis in a simple and novel culture system

Abstract

An industrial-scale, profitable method for production of the most widely used bioinsecticide, Bacillus thuringiensis (Bt), is challenging because of its widespread application. The aim of this study is to present a strategy to develop a low-cost, large-scale bioprocess to produce Bt H14.

This study was first focused on the design of a culture medium composed of economical and available components, such as glycerol and lysed Saccharomyces cerevisiae. The production goal of 1200 ITU was achieved using a medium composed of 20:20 g L^?1of glycerol:lysed yeast in batch cultures. Efforts were subsequently focused on the design of an appropriate culture system, and an original two-stage culture system was proposed. First, yeast (the primary component of the culture medium) are cultivated using a minimal mineral medium and lysed, and in the second stage, Bt is cultivated in the same bioreactor using the lysed yeasts as culture medium (supplemented with a feeding pulse of 10 g L^?1 glycerol). This system was called fed batch one pot (FOP). A new inoculation strategy is also presented in this study, since these Bt cultures were inoculated directly with heat pre-treated spores instead of vegetative bacteria to facilitate the bioprocess. This study was developed from the laboratory to production-scale bioreactors (measuring from 500 mL to 2500 L), and the efficiency of the proposed strategy was evident in LD₅₀ tests results, achieving 1796 ITU in large-scale processes. Both the use of non-conventional sources and the process development for biomass production are important for cost-effective production of Bt-based insecticides in mosquito control projects.     

Importance of Sulfate Aerosol in Evaluating the Relative Contributions of Regional Emissions to the Historical Global Temperature Change

During the negotiations of the KyotoProtocol the delegation of Brazil presentedan approach for distributing the burden ofemissions reductions among the Partiesbased on the effect of their cumulativehistorical emissions on the global-averagenear-surface temperature. The Letter tothe Parties does not limit the emissions tobe considered to be only greenhouse gas(GHG) emissions. Thus, in this paper weexplore the importance of anthropogenicSO_x emissions that are converted tosulfate aerosol in the atmosphere, togetherwith the cumulative greenhouse gasemissions, in attributing historicaltemperature change. We use historicalemissions and our simple climate model toestimate the relative contributions toglobal warming of the regional emissions byfour Parties: OECD90, Africa and LatinAmerica, Asia, and Eastern Europe and theFormer Soviet Union. Our results show thatfor most Parties the large warmingcontributed by their GHG emissions islargely offset by the correspondingly largecooling by their SO_x emissions. Thus,OECD90 has become the dominant contributorto recent global warming following itslarge reduction in SO_x emissions after1980.     

Analysing countries’ contribution to climate change: scientific and policy-related choices

This paper evaluates the influence of different policy-related and scientific choices on the calculated regional contributions to global climate change (the “Brazilian Proposal”). Policy-related choices include the time period of emissions, the mix of greenhouse gases and different indicators of climate change impacts. The scientific choices include historical emissions and model representations of the climate system. We generated and compared results of several simple climate models. We find that the relative contributions of different nations to global climate change—from emissions of greenhouse gases alone—are quite robust, despite the varying model complexity and differences in calculated absolute changes. For the default calculations, the average calculated contributions to the global mean surface temperature increase in 2000 are about 40% from OECD, 14% from Eastern Europe and Former Soviet Union, 24% from Asia and 22% from Africa and Latin America. Policy-related choices, such as time period of emissions, climate change indicator and gas mix generally have larger influence on the results than scientific choices. More specifically, choosing a later attribution start date (1990 instead of 1890) for historical emissions, decreases the contributions of regions that started emitting early, such as the OECD countries by 6 percentage points, whereas it increases the contribution of late emitters such as Asia by 8 percentage points. However, only including the fossil CO₂ emissions instead of the emissions of all Kyoto gases (fossil and land use change), increases the OECD contributions by 21 percentage points and decreases the contribution of Asia by 14 percentage points.     

Liquid chromatography-hydride generation-atomic absorption spectrometry for the speciation of tin in seafoods

Liquid chromatography with hydride generation atomic absorption spectrometry as the detection system was applied to the separation and determination of inorganic tin, tributyltin, dibutyltin, monobutyltin, diphenyltin and monophenyltin. A reversed phase C18 column and a methanol/water/acetic acid (70:27:3, v/v/v) mixture containing 0.05%(v/v) triethylamine and 0.1%(w/v) tropolone as the mobile phase (isocratic elution) were used. Extraction of organotins from the samples was carried out using methanol containing 0.05%(w/v) tropolone, a process that was repeated twice. The supernatants were shaken with water and dichloromethane in a separating funnel and the organic phase was collected and evaporated to dryness. When the method was applied to the speciation of tin in fresh and canned mussels, no organotins above the detection limits were identified in any of the samples, inorganic tin being the only species detected. The reliability of the procedure was checked by analyzing the total tin content of the samples by electrothermal atomic absorption spectrometry and by speciation of tin in a certified reference material, mussel tissue (CRM 477). The method can be used for environmental monitoring of organotins contaminated samples.     

A Gradient Study of 34 Elements in the Vicinity of a Copper-Nickel Smelter in the Kola Peninsula

Concentrations of 34 elements determined by ICP mass spectrometry were studied in surface soil and vegetation along a north–south gradient through the Pechenganickel smelter complex in Kola peninsula, northern Russia. Strong influence from the smelter was evident for Fe, Co, Ni, and Cu, mainly associated with dry deposition of large particles. Also for As, Se, Mo, Sb, Te, Bi, and Pb the smelter or associated sources appeared to be distinct contributors of contamination consisting presumably of smaller particles. Significant but less distinct effects leading to enhanced concentration levels were observed for P, S, V, Cr, Zn, and Tl. In the case of Mn, Rb, Sr, Cs, and Ba the concentrations in vegetation were generally lower near the source, which may be due to cation exchange with protons or heavy metal cations in the soil and subsequent leaching from the root zone. For Li, Be, B, Na, Mg, Al, Ca, Y, Cd, La, Th, and U no particular influence from the smelter complex was observed. Some characteristic differences observed in element concentrations in different plant species and between different years of Pinus sylvestris needles are discussed. The high concentrations observed for many trace elements in the humus horizon indicates that it acts as an active biogeochemical barrier against downward transport of these elements.     

Antibodies Against Hepatitis E Virus (HEV) in European Moose and White-Tailed Deer in Finland

Food and Environmental Virology - The main animal reservoirs of zoonotic hepatitis E virus (HEV) are domestic pigs and wild boars, but HEV also infects cervids. In this study, we estimated the...     

Artisanal fishers’ ethnobotany: from plant diversity use to agrobiodiversity management

Artisanal fishers interact with plants in many ways, and with different intensities. In spite of being characterized by fisheries, Caiçaras use plants with varied degrees of management, since the less intensive management actions, extraction of forest products, until intensively management actions through the cultivation of the agrobiodiversity. This study presents the results of different research projects and includes the North and the South regions of São Paulo state coast. The objective is to characterize the diversity of extracted and cultivated species by traditional fishers at Southeastern region of Brazilian Atlantic forest. Ethnobotanical surveys revealed a high diversity of plants known and used, ranging up to a richness of 272 species known in two communities for the South coast, most of them being native. However, depending on the management intensity, this diversity can be rather particularized: we found 68 varieties of cassava (Manihot esculenta Crantz) at North region and 58 varieties at the South region, with exclusive vernacular names. Through an ethnobotanical perspective, we compare and discuss the different dynamic systems underlying the relationships between fishers and plants. The diversity of cultivated plants is analyzed in depth, focusing on the historical importance of agriculture among people who are currently characterized as fishers. A schematic model is proposed to explain the dynamic systems operating in the relationships between fishers and plants.