Ultrastructure of dermal denticles in sharpnose shark (Rhizoprionodon lalandii) (Elasmobranchii,Carcharhinidae)

The presence of denticles in the external surface, oral cavity, fins, and clasper of Elasmobranchii has been widely reported. These structures, called body denticles, may be observed on the body surface of sharks. Dermal and oral denticles are made up by a basal plate that is embedded in the dermis, forming a peduncle that grows from the base to the crown. These denticles may protect the skin against abrasion, and improve hydrodynamics and gill arches function. Rhizoprionodon lalandii is a widely distributed and very common species in Brazilian coastal areas. The aims of this study was to compare the morphology of oral and body denticles of R. lalandii to understand the implications of these structures in the behavior of these animals. Morphological analysis showed that there are differences between dermal and oral denticles, which are related to their role in different body regions. Body denticles have three cusps, and well‐defined crests and ridges, and literature data suggest that suggest that hydrodynamics is their main function. Most of the oral denticles have only one cusp, and their morphology and distribution showed that their main functions are preparing food to be swallowed and protecting the oral cavity against abrasion. Microsc. Res. Tech. 78:859–864, 2015. © 2015 Wiley Periodicals, Inc.     

Mechanical and microstructural characterization of 2124Al/25 vol.%SiCp joints obtained by linear friction welding (LFW)

The aim of this study is to evaluate the possibility of using the linear friction welding (LFW) technique to produce sound joints on a 2124Al/25 vol.%SiC_p composite. The MMC joints were subjected to microstructural and mechanical characterization, including hardness, tensile and fatigue tests, without any post-weld heat treatment. The microstructural analyses showed substantially defect-free joints, with a uniform particle distribution in the central zone and a relevant plastic flow of the aluminium matrix alloy. The hardness decrease in the welded zone was approximately 10% in respect to the base material. The joint efficiency was higher than 80%, both in respect to the ultimate tensile strength and fatigue strength at 10⁷ cycles. S–N probability curves were calculated using the maximum likelihood method. Generally, the fracture occurred in the Thermo-Mechanically Affected Zone (TMAZ), with a relevant reduction in the elongation to failure.     

Targeting acetylcholinesterase molecules to the neuromuscular synapse

The functional integrity of the neuromuscular synapse requires that sufficient numbers of acetylcholinesterase (AChE) molecules be localized on the specialized extracellular matrix between the nerve terminal and the post-synaptic membrane. Multiple interrelated levels of regulation are necessary to accomplish this complex task including the spatial and temporal restriction of AChE mRNA expression within the muscle fiber, local translation and assembly of AChE polypeptides, and focused accumulation of AChE molecules on the extracellular matrix. This is accomplished in part through the organization of other extracellular matrix molecules into a complex which further associates with acetylcholine receptors and their accompanying molecules. Finally, the mature neuromuscular junction contains molecules which can act as receptors for the attachment of AChE which in turn may allow for the turnover of this enzyme at the synapse. This brief review will focus mainly on contributions from our laboratory towards understanding the mechanisms involved in organizing AChE molecules at the neuromuscular synapse.     

Unemployed individuals: Motives, job-search competencies, and job-search constraints as predictors of job seeking and reemployment.

This study investigated 3 broad classes of individual-differences variables (job-search motives, competencies, and constraints) as predictors of job-search intensity among 292 unemployed job seekers. Also assessed was the relationship between job-search intensity and reemployment success in a longitudinal context. Results show significant relationships between the predictors employment commitment, financial hardship, job-search self-efficacy, and motivation control and the outcome job-search intensity. Support was not found for a relationship between perceived job-search constraints and job-search intensity. Motivation control was highlighted as the only lagged predictor of job-search intensity over time for those who were continuously unemployed. Job-search intensity predicted Time 2 reemployment status for the sample as a whole, but not reemployment quality for those who found jobs over the study's duration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antennal olfactory responses to individual cereal volatiles in Theocolax elegans (Westwood) (Hymenoptera: Pteromalidae)

Theocolax elegans (Westwood) is a pteromalid wasp that parasitizes immature stages of stored-grain insect pests. In a previous study, uninfested wheat kernels and their hexane extracts were shown to be attractive to the adult wasps. To contribute to the understanding of the olfactory basis of the host-habitat recognition, the electroantennographic (EAG) responses of both sexes of T. elegans to a range of volatile compounds previously identified from grains of various cereals were recorded. All compounds tested elicited measurable EAG responses. The largest EAG amplitudes were evoked by 2-octanone, 1-hexanol, 2-heptanone, (E)-2-nonenal, decanal, (E)-2-hexenal, propionic acid, (E)-2-octenal and hexanoic acid in males, and by propionic acid, 2-hexanone, (E)-2-heptenal, 2-heptanone, hexanal, (E,E)-2,4-heptadienal, butanal, hexanoic acid and octanal in females. Aromatic compounds were the weaker antennal stimulants in both sexes. Sexual differences in the EAG amplitude to some compounds were found, with males being significantly more responsive to 13 of the 34 compounds tested. Comparison of EAG responses to various chemicals indicated a strong antennal capability to differentiate in respect to structure (aliphatics and aromatics), carbon chain length, functional group (acid, alcohol, aldehyde, ketone) and absence/presence of double bonds (saturated, mono- and di-unsaturated compounds). Possible roles of cereal volatiles in host-habitat location of T. elegans are discussed in relation to the possible future implementation of T. elegans-based biological control strategies.     

Scent trailing by virgin females ofPseudococcm calceolariae

Virgin females of the citrophilous mealybugPseudococcus calceolariae (Mask.) deposit scent marks as trails on the substrate on which they rest or move. These substances elicit attraction and sexual behavior by conspecific males. The same responses were obtained when males were bioassayed on extracts from filter paper disks on which females had rested. The significance of scent trailing in mealybugs is discussed.Homoptera, Coccoidea, Pseudococcidae.This work was supported by the Italian National Research Council (CNR).     

Behavioral Responses of Adult <Emphasis Type="Italic">Sitophilus granarius</Emphasis> to Individual Cereal Volatiles

The antennae of Sitophilus granarius (L.) (Coleoptera: Curculionidae) adults detect a wide variety of compounds in the odor blend of various cereal grains (Germinara et al., Tec. Molit., 53:27–34, 2002). In the present study, we looked at the behavioral responses of the granary weevil to 20 of these individual volatiles (aliphatic alcohols, aldehydes, ketones, and aromatics) in a two-choice pitfall olfactometer, using the aggregation pheromone and propionic acid as the attractant and repellent controls, respectively. Five doses, ranging from 1 μg to 1 mg, of each compound were tested. At least one concentration of eight compounds attracted beetles but required doses 1,000- to 5,000-fold higher than the concentration of aggregation pheromone to elicit a response. Three compounds, while attractive at lower concentrations, acted as repellents at higher doses. Twelve compounds were repellent at concentrations similar to the quantity of propionic acid that significantly repelled beetles. The data show that granary weevil adults have the ability to respond behaviorally to a wide range of cereal volatiles and that responses may change as a function of concentration. The results suggest that host finding behavior of weevils will depend on the balance of positive and negative volatile stimuli from grain as the relative concentrations of volatiles may change during storage. An understanding of how the weevils respond to such changes could be useful for the development of effective integrated pest management strategies.     

Electrophysiological and behavioral activity of (E)-2-hexenal in the granary weevil and its application in food packaging

The purpose of this work was to develop a biodegradable carrier material to control insect pests in cereal products. To this aim, (E)-2-hexenal was used, being a natural compound with antimicrobial activity that is also commonly adopted as a flavoring agent. Three coating layers of polycaprolactone (PCL) were spread onto the internal side of a paperboard carton, the first being the active coating containing (E)-2-hexenal. The antennal sensitivity of Sitophilus granarius to a broad range of doses of (E)-2-hexenal was first demonstrated. Next, the ability of different concentrations of this compound to disrupt the orientation of adult S. granarius beetles to odors of intact wheat kernels was established in a two-choice pitfall bioassay. In addition, invasion tests were carried out over an 8-week period to highlight the effects of the biobased repellent packaging and their potential persistence. The results demonstrated that during the entire monitoring period, the percentage of S. granarius adults found in cartons coated with (E)-2-hexenal-loaded multilayer PCL was about 10 % of the total number of insects used in the bioassay, very low compared with the respective control samples, thus assessing both the effectiveness and persistence of the repellent system developed. Although the infestation level of treated packages was reduced relative to the infestation levels in the controls, any infestation of food packages is unacceptable to consumers, so further tests are required to determine whether infestation can be completely prevented using (E)-2-hexenal.     

A meta-analytic review of gender differences in perceptions of sexual harassment.

Research on gender differences in perceptions of sexual harassment informs an ongoing legal debate regarding the use of a reasonable person standard instead of a reasonable woman standard to evaluate sexual harassment claims. The authors report a meta-analysis of 62 studies of gender differences in harassment perceptions. An earlier quantitative review combined all types of social–sexual behaviors for a single meta-analysis; the purpose of this study was to investigate whether the magnitude of the female–male difference varies by type of behavior. An overall standardized mean difference of 0.30 was found, suggesting that women perceive a broader range of social–sexual behaviors as harassing. However, the meta-analysis also found that the female–male difference was larger for behaviors that involve hostile work environment harassment, derogatory attitudes toward women, dating pressure, or physical sexual contact than sexual propositions or sexual coercion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)