Are conservation units in the Caatinga biome,Brazil, efficient in the protection of biodiversity? An analysis based on the drosophilid fauna

Biodiversity is believed to be low in regions with vegetation that has adapted to water stress. Additionally, there is little interest by authorities in establishing and expanding conservation units in these areas. In Brazil, the Caatinga and the Cerrado biomes comprise this xerophilous vegetation. In both, climate is tropical and the dry season is long and well-defined. The Caatinga is the Brazilian biome with the smallest area protected by conservation units. This study evaluates the efficacy of conservation units in the Caatinga biome based on abundance and richness of drosophilids. Flies were collected inside and outside these areas. In total, approximately 23,000 flies of 32 species were collected in six conservation and six non-conservation sites. Two non-described species occurred exclusively inside protected areas, underlining the importance of conservation efforts in the maintenance of biodiversity. Other species were recorded exclusively outside conservation areas, which emphasizes the importance of establishing and expanding conservation units in the Caatinga. Native species were significantly more abundant inside conservation units, though the richness was similar in protected and non-protected areas. Abundance of exotic species outside conservation areas was statistically different in comparison with that of native ones.     

Is there an energy conservation “system” in brain that protects against the consequences of energy depletion?

A poorly understood marked decrease (circa 50% of control) in local cerebral glucose utilization is caused by sublethal doses of NaCN. The decrease is global, occurring in essentially all brain regions and is entirely reversible within hours, leaving no obvious pathology. This event is not unique to NaCN in so far as a strikingly similar pattern of decreased glucose utilization occus with some other toxins. Nor can it be attributed to a direct action of NaCN since local application by microdialysis to the striatum produces a global depression. These results imply that some widely distributed system or substance is involved. We speculate the existence of a system possibly related to the reticular activating system that senses a fall in energy production and acts globally to make cells quiescent and thus would give some protection from excitotoxic driven damage.Special issue dedicated to Dr. Sidney Ochs.     

METAPOP—A software for the management and analysis of subdivided populations in conservation programs

We introduce a computer program for the dynamic and flexible management of conserved subdivided populations. Using molecular marker data or pedigree information, the software determines the optimal contributions (i.e., number of offspring) of each individual, the number of migrants, and the particular subpopulations involved in the exchange of individuals in order to maintain the largest level of gene diversity in the whole population with a desired control in the rate of inbreeding. Restrictions can be introduced for the total number of migrants, and the mating of particular pairs and their contribution. A full genetic diversity analysis of the population is carried out. The optimal contribution from each subpopulation to a pool of maximal gene diversity is also provided by the program.     

Functional role of β domain in the Thermoanaerobacter tengcongensis glucoamylase

Thermoanaerobacter tengcongensis MB4 glucoamylase (TteGA) contains a catalytic domain (CD), which is structurally similar to eukaryotic GA, and a β domain (BD) with ambiguous function. Firstly, BD is found to be essential to TteGA activity because CD alone could not hydrolyze soluble starch. However, starch hydrolysis activity, similar to that of intact TteGA, was restored to CD in the presence of BD. Secondly, BD is found to be an important helper in the correct folding of CD because CD was mainly expressed in the inclusion bodies on its own in Escherichia coli. By contrast, intact TteGA, BD, and CD combined with BD could be expressed as soluble proteins. Additionally, BD is essential to the thermostability of TteGA because CD displayed lower thermostability compared with the intact TteGA and exhibited enhanced thermostability in the presence of BD in vitro. Truncation of TteGA or mutagenesis of the residues that participate in the interdomain interaction at its BD also led to the reduced thermostability of TteGA.     

Habitat suitability models for the conservation of thermophilic grasshoppers and bush crickets—simple or complex?

One goal of conservation biology is the assessment of effects of land use change on species distribution. One approach for identifying the factors, which determine habitat suitability for a species are statistical habitat distribution models. These models are quantitative and can be used for predictions in management scenarios. However, they often have one major shortcoming, which is their complexity. This means that they need several, often costly-to-determine parameters for predictions of species occurrence. We first used habitat suitability models to investigate and determine habitat preferences of three different Orthoptera species. Second, we compared the predictive powers of simple habitat suitability models considering only the ‘habitat type’ as predictor with more complex models taking different habitat factors into account. We found that the habitat type is the most reliable and robust factor, which determines the occurrence of the species studied. Thus, analyses of habitat suitability can easily be carried out on the basis of existing vegetation maps for the conservation of the three species under study. Our results can serve as a basis for the estimation of spatio-temporal distribution and survival probabilities of the species studied and might also be valuable for other species living in dry grasslands.     

Phytosociological,structural and conservation analysis of the habitats of Dupont’s lark in Europe: a phytosociological survey applied to the conservation of an endangered species

Based on an updated census for the endangered Dupont’s lark (Chersophilus duponti), we conducted a phytosociological survey of 167 sites representative of the distribution area of the species in Europe. Results were used as a starting point for conservation assessment. According to our observations, the bird selects flat deforested areas colonized by small shrubs corresponding to successional, subclimax stages that are either naturally or artificially exploited. Four groups of scrubs were occupied by the bird: (1) supramediterranean dwarf cushion scrubs dominated by Genista pumila ssp. rigidissima or Erinacea anthyllis; (2) gypicolous shrublands and grasslands associated with Lygeum spartum; (3) shrubs dominated by chamaephytes producing allelopathic substances (Thymus, Lavandula, Salvia) and showing different facies according to the level of disturbance; and (4) supramediterranean acidophilous scrubs dominated by Cistus, Erica or Cytisus species. As management measures, we propose reducing tree density in flat areas, promoting the growth of chamaephytes by clearing phanerophytes, and encouraging traditional low-level transhumance grazing. These measures will provide high-quality habitats and help preserve, or even expand, habitable patches to ensure the viability of the European metapopulation of this rare and sensitive songbird.     

Is bigger always better? A critical appraisal of the use of volumetric analysis in the study of the hippocampus

A well-developed spatial memory is important for many animals, but appears especially important for scatter-hoarding species. Consequently, the scatter-hoarding system provides an excellent paradigm in which to study the integrative aspects of memory use within an ecological and evolutionary framework. One of the main tenets of this paradigm is that selection for enhanced spatial memory for cache locations should specialize the brain areas involved in memory. One such brain area is the hippocampus (Hp). Many studies have examined this adaptive specialization hypothesis, typically relating spatial memory to Hp volume. However, it is unclear how the volume of the Hp is related to its function for spatial memory. Thus, the goal of this article is to evaluate volume as a main measurement of the degree of morphological and physiological adaptation of the Hp as it relates to memory. We will briefly review the evidence for the specialization of memory in food-hoarding animals and discuss the philosophy behind volume as the main currency. We will then examine the problems associated with this approach, attempting to understand the advantages and limitations of using volume and discuss alternatives that might yield more specific hypotheses. Overall, there is strong evidence that the Hp is involved in the specialization of spatial memory in scatter-hoarding animals. However, volume may be only a coarse proxy for more relevant and subtle changes in the structure of the brain underlying changes in behaviour. To better understand the nature of this brain/memory relationship, we suggest focusing on more specific and relevant features of the Hp, such as the number or size of neurons, variation in connectivity depending on dendritic and axonal arborization and the number of synapses. These should generate more specific hypotheses derived from a solid theoretical background and should provide a better understanding of both neural mechanisms of memory and their evolution.     

An analysis of temperature adaptation in cold active, mesophilic and thermophilic Bacillus α-amylases

A comparative biochemical and structural study was performed on a cold active α-amylase from Bacillus cereus (BCA) and two well-known homologous mesophilic and thermophilic α-amylases from Bacillus amyloliquefaciens (BAA) and Bacillus licheniformis (BLA). In spite of a high degree of sequence and structural similarity, drastic variations were found for T_opt as 50, 70 and 90 °C for BCA, BAA and BLA, respectively. The half-lives of thermoinactivation were 1 and 9 min for BCA and BAA at 80 °C respectively, whilst there was no inactivation for BLA at this temperature. Thermodynamic studies on inactivation process suggested that lower thermostability of BCA is due to lower inactivation slope of the Arrhenius plots and subsequently, lower E_a and ΔH^#. Increased K_m and accessible surface area for catalytic residues along with a decreased number of internal interactions in this region in BCA compared to BLA suggest that BCA substrate-binding site might be temperature sensitive and is probably more flexible. On the other hand, fewer ion pairs, destructive substitutions and disruption of aromatic interaction networks in structurally critical regions of Bacillus α-amylases result in a severe decrease in BCA thermostability compared to its mesophilic and thermophilic homologues.     

Is the ubiquinone pool in the respiratory chain of the bacterium Paracoccus denitrificans really unhomogeneous?

We have established the participation of a mobile redox pool in the respiratory chain of anaerobically grown bacterium Paracoccus denitrificans. In testing the kinetical homogeneity of the pool it was found that the ratio of fluxes of electron transport toward the terminal acceptors oxygen and nitrate was coincident for the respiratory substrates NADH and succinate; this provides evidence against the preferential link of one dehydrogenase with a distinct terminal enzyme through the separate pool of ubiquinone. The deviation from the expected behavior observed in comparing the titration of NADH oxidase and succinate oxidase with respiratory inhibitors such as mucidin (inhibitor in the bc₁ region) or cyanide can be accounted for by the activation of succinate dehydrogenase upon the increase in the reduced state of respiratory components during the titration.     

Recycling ofd-glucose in collagenous cuticle: A means of nutrient conservation?

Summary Transport by an epithelium, possessing an accumulating, saturable transport system in the apical membrane as well as a finite Fick permeability to the transported solute, was considered in the steady state in the case of zerocis concentration, and in the presence of a peripheral diffusion resistance in a layer apposing thecis face of the tissue (unstirred solution or structural coating). Under suitable conditions, the combination of peripheral diffusion resistance and accumulating epithelial transport may lead to recycling of solute at thecis face of the epithelium. This causes a decrease of the effective permeability to diffusionaltrans-cis flow across the tissue. The phenomenon is discussed in terms of epidermald-glucose transport by the integument of aquatic animals with a collagenous cuticle, such as the seawater-acclimated polychaete wormNereis diversicolor. The recycling phenomenon may be of significance to other epithelia with the function of maintaining large concentration gradients of permeating substances.List of Symbols and Fixed Parameter Values C _m Bulk medium solute concentration,cis face of epidermisC _m=0 mol cm^–3 - C _i Concentration of solute at interface between cuticle and unstirred medium (mol cm^–3) - C _s Concentration of solute atcis face of apical epidermal membrane (mol cm^–3) - C _e Concentration of solute in extracellular fluid,trans-side of epidermisC _e=1.0×10^–6 mol cm^–3 - D _m Diffusion coefficient of solute in outside mediumD _m=6.7×10^–6 cm² sec^–1 - D _c Diffusion coefficient of solute in cuticleD _c=7.4×10^–9 cm² sec^–1 - _m Operative thickness of unstirred medium layer - _c Thickness of cuticle - J Steady-state net flux of solute through cuticle or unstirred layer (flux is positive indirectioncis-trans) (mol cm^–2 sec^–1) - J _i ^max Maximal influx through saturable transport system in apical membraneJ _i ^max =2.0×10^–12 mol cm^–2 sec^–1 - K _t Transport constant, saturable systemK _t=1.0×10^–7 mol cm^–3 - P Epithelial permeability (cm sec^–1)     

Identification of a VapBC toxin–antitoxin system in a thermophilic bacterium Thermus thermophilus HB27

Extremophiles - There are 12 putative toxin–antitoxin (TA) loci in the Thermus thermophilus HB27 genome, including four VapBC and three HicBA families. Expression of these seven putative...     

An ontological crisis? A review of large felid conservation in India

The need for a solid knowledge base to inform conservation activity is now universally recognised. We critically scrutinised the scientific knowledge of large felids in India located in peer-reviewed research papers to assess the information available to make landscape-level management decisions that aid conservation, which is a stated goal of both the Indian government and the international community. We found two striking patterns: the biological sciences dominate in the published literature, and nearly all the research has been carried out in protected areas, though a substantial number of large felids also live outside protected areas. We argue that these patterns are not incidental, but the result of the dualistic ontology of science that uses processes of ‘purification’ and ‘translation’ to fit complex realities into disciplinary prerogatives organised around creating dichotomies (like nature–culture). In addition, since this body of scientific knowledge locates large felids in ‘pure’ biological landscapes, there is little or no insight from multi-use landscapes. These findings, we believe, highlight important knowledge gaps in our present research-based knowledge of large felids in India, which urgently need to be addressed if progress is to be made in conservation.     

What are 60 warblers worth? Killing in the name of conservation

Ecological research sometimes entails animal suffering and even animal killing. The ethical appropriateness of animal suffering and killing in conservation research may entail considerations that differ from many other kinds of research. This is true, insomuch as conservation research is specifically motivated by an ethical premise: an appreciation for non-human life. In striking contrast with other academic fields (e.g. medicine), however, the ethical dimension of conservation research is only rarely discussed. When it is discussed, it tends to be characterized by logical errors. These errors are important because they are general (i.e. both common and with far-reaching implications), and they are easily made by intelligent people; especially those with no formal training in ethics or logic. Failure to recognize these errors could stymie efforts to increase the ethical quality of ecological research conducted in the name of conservation.
We take advantage of a recently published dialogue concerning the ethical appropriateness of a specific field experiment that entailed killing black-throated blue warblers, Dendroica caerulescens . Both sides of this debate exemplify the kinds of errors to which we refer. In this paper we briefly review the arguments presented on each side of this debate, highlight their mistakes, and indicate necessary corrections. We argue that: (1) compliance with animal research regulations, while important, inadequately accommodates the ethical aspects of animal research, and (2) individual ecologists ought to understand themselves what does and does not represent sound and valid arguments for ethical decisions. Finally, we discuss how any ecological researcher might begin to apply our analysis to his or her own research.     

Who likes it hot? A global analysis of the climatic,ecological, and evolutionary determinants of warming tolerance in ants

Effects of climate warming on wild populations of organisms are expected to be greatest at higher latitudes, paralleling greater anticipated increases in temperature in these regions. Yet, these expectations assume that populations in different regions are equally susceptible to the effects of warming. This is unlikely to be the case. Here, we develop a series of predictive models for physiological thermal tolerances in ants based on current and future climates. We found that tropical ants have lower warming tolerances, a metric of susceptibility to climate warming, than temperate ants despite greater increases in temperature at higher latitudes. Using climatic, ecological and phylogenetic data, we refine our predictions of which ants (across all regions) were most susceptible to climate warming. We found that ants occupying warmer and more mesic forested habitats at lower elevations are the most physiologically susceptible to deleterious effects of climate warming. Phylogenetic history was also a strong indicator of physiological susceptibility. In short, we find that ants that live in the canopies of hot, tropical forest are the most at risk, globally, from climate warming. Unfortunately this is where many, perhaps most, ant and other species on Earth live.     

Is the Natura 2000 network sufficient for conservation of butterfly diversity? A case study in Slovenia

Slovenia has one of the most extensive Natura 2000 networks in Europe with 259 SAC’s covering 31.4% of the country. To determine how well does the current network cover the areas of high butterfly diversity and/or aggregation of the butterfly species of conservation concern, the data from the recent survey for a distribution atlas were used. Altogether 99,423 records of 173 species collated after 1979 were used. The data distribution is slightly biased towards SAC’s, with 44.8% of localities within them, most likely due to sparsely sampled urban areas and intensive farmland areas which are found only outside SAC’s. The diversity and distribution of red listed species was evaluated at a 5 × 5 km grid square level. Additionally the importance of the size of the SAC’s was compared to their butterfly species diversity. In general the high diversity areas also hold the largest aggregation of red listed species with core areas concentrated in SW Slovenia. The SAC’s cover majority of areas with high diversity and the distribution of all but one threatened butterfly species. That species is Colias myrmidone, which is now considered extinct in Slovenia with no records after 1993. The most prominent areas with high conservation value in Slovenia not included in the SAC’s network are the Koro?ka region, Gori?ka Brda region, lower Sava River valley and Slovenske Gorice region. The butterfly diversity in small SAC’s is relatively high with increases in size only gradually increasing the species numbers, thus emphasizing the importance and conservation value of small SAC’s for sustaining high butterfly diversity in Slovenia.     

Does the antibacterial activity of silver nanoparticles depend on the shape of the nanoparticle? A study of the Gram-negative bacterium Escherichia coli

In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron microscopy images revealed considerable changes in the cell membranes upon treatment, resulting in cell death. Truncated triangular silver nanoplates with a {111} lattice plane as the basal plane displayed the strongest biocidal action, compared with spherical and rod-shaped nanoparticles and with Ag(+) (in the form of AgNO(3)). It is proposed that nanoscale size and the presence of a {111} plane combine to promote this biocidal property. To our knowledge, this is the first comparative study on the bactericidal properties of silver nanoparticles of different shapes, and our results demonstrate that silver nanoparticles undergo a shape-dependent interaction with the gram-negative organism E. coli.