Seasonal and spatial species richness variation of dung beetle (Coleoptera, Scarabaeidae s. str.) in the Atlantic Forest of southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Selective defaunation affects dung beetle communities in continuous Atlantic rainforest

Overhunting has caused severe decline or local extinction in many large-bodied mammals with direct consequences on plant regeneration, yet little is known about indirect impacts of selective defaunation on commensal species. Cascading effects of species extinction across dependent species groups are likely to occur in coprophagous beetles, because these invertebrates rely on mammal dung for food and nesting material. Both mammals and dung beetles provide important ecosystem services and cascading effects are likely to lead to rapid functional losses. In this study, we described changes in dung beetle communities across a gradient of selective defaunation in continuous Brazilian Atlantic rain forest. We compared the dung beetle assemblages in seven sites with different mammalian biomass and composition. The reduction in the mammalian biomass had a major effect on dung beetle communities by (1) increasing dung beetle abundance with decreasing overall mammal, primate and large mammal biomasses, (2) decreasing dung beetle species richness with decreasing overall mammal biomass and (3) decreasing dung beetle size with decreasing large mammal biomass. Moreover, our study demonstrated the importance of the composition of mammal communities in structuring dung beetle communities. This study documented how selective changes in mammalian biomass and composition affect dung beetle species communities, which in turn may have cascading consequences for the ecosystem. Since most of tropical ecosystems are facing dramatic changes in mammalian composition, it is urgent to evaluate the functional losses associated with such co-extinctions. © 2013 Elsevier Ltd.

Acorn consumption improves the immune response of the dung beetle Thorectes lusitanicus

Thorectes lusitanicus, a typically coprophagous species is also actively attracted to oak acorns, consuming, burying them, and conferring ecophysiological and reproductive advantages to both the beetle and the tree. In this study, we explored the possible relation between diet shift and the health status of T. lusitanicus using a generalist entomopathogenic fungus (Metarhizium anisopliae) as a natural pathogen. To measure the health condition and immune response of beetles, we analysed the protein content in the haemolymph, prophenoloxidase (proPO) content, phenoloxidase (PO) activity and mortality of beetles with diets based on either acorns or cow dung. Protein content, proPO levels and PO levels in the haemolymph of T. lusitanicus were found to be dependent on the type of diet. Furthermore, the beetles fed with acorns developed a more effective proPO-PO system than the beetles fed with cow dung. Furthermore, a significant decrease in mortality was observed when infected individuals were submitted to an acorn-based diet. In addition to enhancing an understanding of the relevance of dietary change to the evolutionary biology of dung beetles, these results provide a more general understanding of the ecophysiological implications of differential dietary selection in the context of fitness.

Culturable aerobic and facultative bacteria from the gut of the polyphagic dung beetle Thorectes lusitanicus Jeckel

Unlike other dung beetles, the Iberian geotrupid Thorectes lusitanicus exhibits polyphagous behavior; for example, it is able to eat acorns, fungi, fruits, and carrion in addition to the dung of different mammals. This adaptation to digest a wider diet has physiological and developmental advantages and requires key changes in the composition and diversity of the beetle's gut microbiota. In this study, we isolated aerobic, facultative anaerobic, and aerotolerant microbiota amenable to grow in culture from the gut contents of T. lusitanicus and resolved isolate identity to the species level by sequencing 16S rRNA gene fragments. Using BLAST similarity searches and maximum likelihood phylogenetic analyses, we were able to reveal that the analyzed fraction (culturable, aerobic, facultative anaerobic, and aerotolerant) of beetle gut microbiota is dominated by the phyla Proteobacteria, Firmicutes and Actinobacteria. Among Proteobacteria, members of the order Enterobacteriales (Gammaproteobacteria) were the most abundant. The main functions associated with the bacteria found in the gut of T. lusitanicus would likely include nitrogen fixation, denitrification, detoxification, and diverse defensive roles against pathogens.

Quantification of the relationship between Fuser Roller Temperature and Laser Printer Emissions

Recently published studies not only demonstrated that laser printers are often significant sources of ultrafine particles, but they also shed light on particle formation mechanisms. While the role of fuser roller temperature as a factor affecting particle formation rate has been postulated, its impact has never been quantified. To address this gap in knowledge, this study measured emissions from 30 laser printers in chamber using a standardized printing sequence, as well as monitoring fuser roller temperature. Based on a simplified mass balance equation, the average emission rates of particle number, PM2.5 and O3 were calculated. The results showed that: almost all printers were found to be high particle number emitters (i.e. > 1.01×1010 particles/min); colour printing generated more PM2.5 than monochrome printing; and all printers generated significant amounts of O3. Particle number emissions varied significantly during printing and followed the cycle of fuser roller temperature variation, which points to temperature being the strongest factor controlling emissions. For two sub-groups of printers using the same technology (heating lamps), systematic positive correlations, in the form of a power law, were found between average particle number emission rate and average roller temperature. Other factors, such as fuser material and structure, are also thought to play a role, since no such correlation was found for the remaining two sub-groups of printers using heating lamps, or for the printers using heating strips. In addition, O3 and total PM2.5 were not found to be statistically correlated with fuser temperature.

Engineering the surface of a sugarcane roller mill roll for grip and durability

Roller mills are typically used to crush sugarcane to express the juice from which sugar is manufactured. The mill rolls need to provide sufficient grip to ensure minimal sliding of the sugarcane along the roll surface. The rolls are subject to pressures up to 55 MPa from the sugarcane bagasse (as the sugarcane is called after first being crushed between a pair of rolls). The insoluble component of sugarcane includes typically 10% ash that largely originates from soil that is harvested with the cane. The sugarcane juice is acidic with pH typically between 5.0 and 5.5. As a result of ash and juice, the mill rolls are subjected to a range of abrasive and corrosive wear mechanisms. Solutions to provide grip and resist wear involve the selection of an appropriate roll shell material and compatible hard facing to provide the desired grip and wear characteristics. This paper reviews the various solutions that have been adopted for grip and durability for mill rolls and highlights the advantages and disadvantages of each method.

The combination of empirical mode decomposition and minimum entropy deconvolution for roller bearing diagnostics in non-stationary operation

Diagnostics is based on the characterization of mechanical system condition and allows early detection of a possible fault. Signal processing is an approach widely used in diagnostics, since it allows directly characterizing the state of the system. Several types of advanced signal processing techniques have been proposed in the last decades and added to more conventional ones. Seldom, these techniques are able to consider non-stationary operations. Diagnostics of roller bearings is not an exception of this framework. In this paper, a new vibration signal processing tool, able to perform roller bearing diagnostics in whatever working condition and noise level, is developed on the basis of two data-adaptive techniques as Empirical Mode Decomposition (EMD), Minimum Entropy Deconvolution (MED), coupled by means of the mathematics related to the Hilbert transform. The effectiveness of the new signal processing tool is proven by means of experimental data measured in a test-rig that employs high power industrial size components.

Effectiveness of MED for Fault Diagnosis in Roller Bearings

Diagnostics of rolling element bearings is usually performed by means of vibration signals measured by accelerometers placed in the proximity of the bearing under investigation. The aim is to monitor the integrity of the bearing components, in order to avoid catastrophic failures, or to implement condition based maintenance strategies. In particular, the trend in this field is to combine in a single algorithm different signal-enhancement and signal-analysis techniques. Among the first ones, Minimum Entropy Deconvolution (MED) has been pointed out as a key tool able to highlight the effect of a possible damage in one of the bearing components within the vibration signal. This paper presents the application of this technique to signals collected on a simple test-rig, able to test damaged industrial roller bearings in different working conditions. The effectiveness of the technique has been tested, comparing the results of one undamaged bearing with three bearings artificially damaged in different locations, namely on the inner race, outer race and rollers. Since MED performances are dependent on the filter length, the most suitable value of this parameter is defined on the basis of both the application and measured signals. This represents an original contribution of the paper.

Roller Derby Dolls

In the sprawling outer suburbs of Brisbane, a revolution is brewing. A sassy group of women from all walks of life has a dream: to resurrect the lost sport of full-contact roller derby in Australia. Led by their president Evil Doll, and despite none having experience in business, the roller girls have set up a roller derby league, one of 220 now dotted around the globe. Roller Derby Dolls is a story of female empowerment and of women with a dream—the dream of inspiring women in Australia to strap on the skates and give the sport a go.

A molecular phylogeny of the checkered beetles and a description of Epiclininae a new subfamily (Coleoptera: Cleroidea: Cleridae)

We provide the first molecular phylogeny of the clerid lineage (Coleoptera: Cleridae, Thanerocleridae) within the superfamily Cleroidea to examine the two most recently-proposed hypotheses of higher-level classification. Phylogenetic relationships of checkered beetles were inferred from approximately ~5,000nt of both nuclear and mitochondrial rDNA (28S, 16S, and 12S) and the mitochondrial protein-coding gene COI. A worldwide sample of ~70 genera representing almost a quarter of generic diversity of the clerid lineage was included and phylogenies were reconstructed using Bayesian and Maximum Likelihood approaches. Results support the monophyly of many proposed subfamilies but were not entirely congruent with either current classification system. The subfamilial relationships within the Cleridae are resolved with support for three main lineages. Tillinae are supported as the sister group to all other subfamilies within the Cleridae, whereas Thaneroclerinae, Korynetinae and a new subfamily formally described here, Epiclininae subf. n, form a sister group to Clerinae + Hydnocerinae.

The impact of fuser roller temperature on laser printer particle emission

The emission of particles in the ultrafine range (<100 nm) from laser printers has not been reported until recently (Uhde et al., 2006; He et al., 2007; Morawska et al., 2009). The research reported to date has provided a body of information about printer emissions and shed light on particle formation mechanisms. However, until now, the effect of fuser roller temperature on particle emissions had not been comprehensively investigated...

A comparative analysis of Mitochondrial genomes in Coleoptera (Arthropoda: Insecta) and genome descriptions of six new beetles

Coleoptera is the most diverse group of insects with over 360,000 described species divided into four suborders: Adephaga, Archostemata, Myxophaga, and Polyphaga. In this study, we present six new complete mitochondrial genome (mtgenome) descriptions, including a representative of each suborder, and analyze the evolution of mtgenomes from a comparative framework using all available coleopteran mtgenomes. We propose a modification of atypical cox1 start codons based on sequence alignment to better reflect the conservation observed across species as well as findings of TTG start codons in other genes. We also analyze tRNA-Ser(AGN) anticodons, usually GCU in arthropods, and report a conserved UCU anticodon as a possible synapomorphy across Polyphaga. We further analyze the secondary structure of tRNA-Ser(AGN) and present a consensus structure and an updated covariance model that allows tRNAscan-SE (via the COVE software package) to locate and fold these atypical tRNAs with much greater consistency. We also report secondary structure predictions for both rRNA genes based on conserved stems. All six species of beetle have the same gene order as the ancestral insect. We report noncoding DNA regions, including a small gap region of about 20 bp between tRNA-Ser(UCN) and nad1 that is present in all six genomes, and present results of a base composition analysis.

Revision of the dung beetle genus Temnoplectron Westwood (Coleoptera: Scarabaeidae: Scarabaeini)

Temnoplectron Westwood is revised and five new species described, four from North Queensland: cooki, finnigani, lewisense, monteithi, one from New Guinea: wareo. Temnoplectron reyi Paulian is removed from synonymy with T. politulum Macleay, Temnoplectron laevigatum Matthews is placed in synonymy with T. boucomonti Paulian, T. heurni Paulian and Z howdeni Paulian are synonymised with Z atropolitum Gillet, and T. major Paulian is recognised in Australia for the first time. All known species are redescribed. A key is provided for the 19 species of Temnoplectron and new distribution records are noted. A cladistic analysis of the genus is presented, the results of which suggest at least two origins for flightlessness in the genus. The biogeography of Temnoplectran is discussed with reference to isolation of rainforest blocks during periods of maximum aridity.