Percolation threshold of carbon nanotubes filled unsaturated polyesters

This paper reports on the development of electrically conductive nanocomposites containing multi-walled carbon nanotubes in an unsaturated polyester matrix. The resistivity of the liquid suspension during processing is used to evaluate the quality of the filler dispersion, which is also studied using optical microscopy. The electrical properties of the cured composites are analysed by AC impedance spectroscopy and DC conductivity measurements. The conductivity of the cured nanocomposite follows a statistical percolation model, with percolation threshold at 0.026 wt.% loading of nanotubes. The results obtained show that unsaturated polyesters are a matrix suitable for the preparation of electrically conductive thermosetting nanocomposites at low nanotube concentrations. The effect of carbon nanotubes reaggregation on the electrical properties of the spatial structure generated is discussed

SHOOTING DOWN THE PRICE: EVIDENCE FROM MAFIA HOMICIDES AND HOUSING MARKET VOLATILITY

In this work, we assess the role of a specific type of organized crime in influencing choices on where living within the city territory, and consequently, volatility in house prices. More specifically, we test how organized crime killing may influence house pricing behaviors. Firstly, we show evidences about how organized crime is associated with higher inequality of housing prices for Italian cities in 2011. Then, by collecting and geo referencing data on the city of Naples for the period 2002-2016, we test for the direct influence of homicides on the relevant territory, as on the neighboring districts. Results show a negative and significant impact of killing on the house prices either for sales or for rents and a positive effect in neighboring district, driving increases in within-city inequality

Subcutaneous emphysema during root canal therapy: endodontic accident by sodium hypoclorite

Cervicofacial subcutaneous emphysema is defined as the abnormal introduction of air in the subcutaneous tissues of the head and neck. It is mainly caused by trauma, head and neck surgery, general anesthesia, and coughing or habitual performance of Valsalva manoeuvre. The occurrence of subcutaneous emphysema after dental treatment is rare, and diffusion of gas into the mediastinum is much rarer, especially when the procedure is a nonsurgical treatment. Presented here is a case of subcutaneous emphysema that occurred after sodium hypochlorite irrigation during endodontic treatment, and the description of its etiologies and prevention during nonsurgical endodontic treatment. Endodontic success can be essentially achieved via good debridement of a root canal, and an ideal endodontic irrigant is effective in removing the smear layer, opening the dentinal tubules, and producing a clean surface for closer obturation

Aggregative oviposition varies with density in processionary moths—Implications for insect outbreak propensity

1. In gregarious insects, groups commonly originate from females laying eggs in masses and feeding groups are established as soon as larvae hatch. Some groupliving insect species may aggregate beyond the individual parent level, such that offspring from two or more egg masses develop within a common resource. 2. Here we show that aggregative oviposition can vary with population density at oviposition and possibly be an important factor in outbreak dynamics of phytophagous insects. 3. We analysed density data with respect to egg mass aggregation for two species of pine processionary moths, Thaumetopoea pinivora (in Sweden 2005–2019) and T. pityocampa (in Spain 1973–1991). Both species lay their eggs in egg masses and feed in groups. During the study periods, insect population density for both species varied by at least an order of magnitude. 4. The two species showed strikingly similar patterns of egg mass aggregation. Egg masses were overdispersed at high population density, with few trees showing a high load of egg masses. 5. Our data suggest that aggregative oviposition can be important in explaining the previously documented higher propensity for outbreaks in insects laying eggs in clusters, compared with those laying individual eggs.European Union's Horizon 2020 Program for Research and Innovation 771271Spanish Governmen

Occurrence, ecological function and medical importance of dermestid beetle hastisetae

Hastisetae are a specific group of detachable setae characterizing the larvae of Megatominae (Coleoptera: Dermestidae), commonly known as carpet and khapra beetles. These setae are located on both thoracic and abdominal tergites and they are the primary defense of the larva against invertebrate predators. According to previous studies, the main purpose of hastisetae is to work as a mechanical obstacle, but they are also capable to block and kill a predator. Hastisetae, single or aggregate, function as an extremely efficient mechanical trap, based on an entangling mechanism of cuticular structures (spines and hairs) and body appendages (antennae, legs and mouthparts). It is believed that this defensive system evolved primarily to contrast predation by invertebrates, however it has been observed that hastisetae may affect vertebrates as well. Although information on the impacts of vertebrate predators of the beetles is lacking, hastisetae have been shown to be a possible threat for human health as an important contaminant of stored products (food and fabric), work and living environment. Review of past and recent literature on dermestid larvae has revealed that despite these structures indicated as one of the distinctive characters in species identification, very little is known about their ultrastructure, evolution and mechanism of action. In the present work, we will provide the state of knowledge on hastisetae in Dermestidae and we will present and discuss future research perspectives intended to bridge the existing knowledge gaps

World Interest Rates, Inequality and Growth: an Empirical Analysis of the Galor-Zeira Model

Following Galor and Zeira (1993), we study the effect of the world interest rate on inequality and growth for the period 1985-2005, characterized by falling world interest rates and cross-country income polarization. We argue that the two phenomena are related on th e basis of the following findings, which are in accordance with the predictions of the Galor and Zeira model: 1) a reduction of the world inter est rates increases inequality in rich countries and decreases inequ ality in poor countries; 2) inequality has a negative (and significant) eff ect on human capital accumulation in rich countries and a positive (b ut mostly not significant) effect in poor countries; 3) human capital po sitively affects GDP in both group of countries, in particular with a higher marginal effect in poor countries. The overall effect of these facts is polarization in the world income distribution

High mobility reduces beta-diversity among orthopteran communities - implications for conservation

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The complete mitochondrial genome of the bag-shelter moth Ochrogaster lunifer (Lepidoptera, Notodontidae)

BACKGROUND: Knowledge of animal mitochondrial genomes is very important to understand their molecular evolution as well as for phylogenetic and population genetic studies. The Lepidoptera encompasses more than 160,000 described species and is one of the largest insect orders. To date only nine lepidopteran mitochondrial DNAs have been fully and two others partly sequenced. Furthermore the taxon sampling is very scant. Thus advance of lepidopteran mitogenomics deeply requires new genomes derived from a broad taxon sampling. In present work we describe the mitochondrial genome of the moth Ochrogaster lunifer. RESULTS: The mitochondrial genome of O. lunifer is a circular molecule 15593 bp long. It includes the entire set of 37 genes usually present in animal mitochondrial genomes. It contains also 7 intergenic spacers. The gene order of the newly sequenced genome is that typical for Lepidoptera and differs from the insect ancestral type for the placement of trnM. The 77.84% A+T content of its alpha strand is the lowest among known lepidopteran genomes. The mitochondrial genome of O. lunifer exhibits one of the most marked C-skew among available insect Pterygota genomes. The protein-coding genes have typical mitochondrial start codons except for cox1 that present an unusual CGA. The O. lunifer genome exhibits the less biased synonymous codon usage among lepidopterans. Comparative genomics analysis study identified atp6, cox1, cox2 as cox3, cob, nad1, nad2, nad4, and nad5 as potential markers for population genetics/phylogenetics studies. A peculiar feature of O. lunifer mitochondrial genome it that the intergenic spacers are mostly made by repetitive sequences. CONCLUSION: The mitochondrial genome of O. lunifer is the first representative of superfamily Noctuoidea that account for about 40% of all described Lepidoptera. New genome shares many features with other known lepidopteran genomes. It differs however for its low A+T content and marked C-skew. Compared to other lepidopteran genomes it is less biased in synonymous codon usage. Comparative evolutionary analysis of lepidopteran mitochondrial genomes allowed the identification of previously neglected coding genes as potential phylogenetic markers. Presence of repetitive elements in intergenic spacers of O. lunifer genome supports the role of DNA slippage as possible mechanism to produce spacers during replication

Disentangling effects of habitat diversity and area on orthopteran species with contrasting mobility

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Egg mass structure of the processionary caterpillar Ochrogaster lunifer (Lepidoptera: Notodontidae): is the outer egg layer sacrificed for attack by the egg parasitoid Anastatus fuligispina (Hymenoptera: Chalcidoidea: Eupelmidae)?

Each life stage of an insect faces the challenge of various mortality factors. Through experimental and observational studies, we use those mortality agents to our advantage to control outbreaks of pest insects. The processionary caterpillar Ochrogaster lunifer Herrich-Schaffer, 1855, is a widespread native moth in Australia that defoliates host trees and causes medical problems in humans and animals. Anastatus fuligispina (Girault 1939) is an egg parasitoid described from eggs of O. lunifer in eastern Australia nearly 80 years ago for which few life history traits are known. This is the first study to investigate the life history of A. fuligispina, factors associated with parasitism levels in O. lunifer egg masses and its impacts on egg mortality. We found that parasitism level was related to the total number of eggs in an O. lunifer egg mass, with higher parasitism occurring in masses with fewer eggs. The inaccessible physical structure of the O. lunifer egg mass by layering and encasing eggs with other eggs and the searching efficiency of the parasitoid are possible key factors. Other variables such as exposure time in the field, host tree species and number of undeveloped eggs in the egg mass did not affect the level of parasitism. Further investigations on the life history of A. fuligispina may open possibilities for its application in controlling O. lunifer populations