Detection of odor perception in Asiatic honeybee (Apis cerana Fabricius, 1793) workers by changing membrane potential of the antennal sensilla

The role of honeybee mandibular gland compounds is poorly understood, although they may act as alarm pheromones. We measured forager and guard bee antennal responses evoked by two major components of mandibular gland secretions of the Asiatic honeybee, Apis cerana. Membrane potentials of antennal sensilla were measured after exposure to three concentrations of the synthetic alarm pheromones 2-heptanone and (Z)-11-eicosen-1-ol using a potentiostat (EA161) connected to an e-corder (ED401) with microelectrodes. The resting membrane potential of A. cerana foragers and guards was -55.23 ± 1.44 and -56.41 ± 1.21. mV, respectively. The membrane potential of foragers after exposure to 1.0, 5.0 and 10.0 2-heptanone was -5.32 ± 0.46, -8.41 ± 1.33 and -11.53 ± 2.16. mV, respectively. The membrane potential of guards was -5.49 ± 1.66, -8.46 ± 1.32 and -7.31 ± 3.46. mV, respectively. Exposure of foragers to 1.0, 5.0 and 10.0 (Z)-11-eicosen-1-ol induced membrane potentials of -24.00 ± 6.56, -36.36 ± 5.18 and -14.60 ± 8.20. mV, respectively; for guards they were -47.62 ± 1.46, -46.08 ± 0.87 and -9.35 ± 1.96. mV, respectively. The highest membrane potential was found in foragers exposed to 1.0 2-heptanone. The membrane potentials of foragers were higher than that of guards except at the highest concentration (10.0) of both pheromones. These findings suggest that antennal sensory receptors of foragers may have higher specific thresholds than those of guards. © 2010 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society

Fluorescently labeled bacteria provide insight on post-mortem microbial transmigration

AbstractMicrobially mediated mechanisms of human decomposition begin immediately after death, and are a driving force for the conversion of a once living organism to a resource of energy and nutrients. Little is known about post-mortem microbiology in cadavers, particularly the community structure of microflora residing within the cadaver and the dynamics of these communities during decomposition. Recent work suggests these bacterial communities undergo taxa turnover and shifts in community composition throughout the post-mortem interval. In this paper we describe how the microbiome of a living host changes and transmigrates within the body after death thus linking the microbiome of a living individual to post-mortem microbiome changes. These differences in the human post-mortem from the ante-mortem microbiome have demonstrated promise as evidence in death investigations. We investigated the post-mortem structure and function dynamics of Staphylococcus aureus and Clostridium perfringens after intranasal inoculation in the animal model Mus musculus L. (mouse) to identify how transmigration of bacterial species can potentially aid in post-mortem interval estimations. S. aureus was tracked using in vivo and in vitro imaging to determine colonization routes associated with different physiological events of host decomposition, while C. perfringens was tracked using culture-based techniques. Samples were collected at discrete time intervals associated with various physiological events and host decomposition beginning at 1h and ending at 60 days post-mortem. Results suggest that S. aureus reaches its highest concentration at 5–7 days post-mortem then begins to rapidly decrease and is undetectable by culture on day 30. The ability to track these organisms as they move in to once considered sterile space may be useful for sampling during autopsy to aid in determining post-mortem interval range estimations, cause of death, and origins associated with the geographic location of human remains during death investigations

Protecting the environment through insect farming as a means to produce protein for use as livestock, poultry, and aquaculture feed

Securing protein for the approximate 10 billion humans expected to inhabit our planet by 2050 is a major priority for the global community. Evidence has accrued over the past 30 years that strongly supports and justifies the sustainable use of insects as a means to produce protein products as feed for pets, livestock, poultry, and aquacultured species. Researchers and entrepreneurs affiliated with universities and industries, respectively, from 18 nations distributed across North and South America, Europe, Asia, Africa and Australia contributed to the development of this article, which is an indication of the global interest on this topic. A brief overview of insects as feed for the aquaculture industry along with a review of the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae), as a model for such systems is provided

Insights into the high-energy γ-ray emission of Markarian 501 from extensive multifrequency observations in the Fermi era

We report on the γ-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) γ-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 ± 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 ± 0.14, and the softest one is 2.51 ± 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size ≲0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (≃1044 erg s-1) constitutes only a small fraction (∼10-3) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude. © 2011. The American Astronomical Society

Bioassay of the mandibular gland pheromones of Apis florea on the foraging activity of dwarf honey bees

In this study, we tested the responses (attractiveness or repellence) of two species of dwarf honey bee (Apis andreniformis and Apis florea) foragers to the synthetic mandibular gland pheromones 1-eicosanol, eicosane, heneicosane and 2-heptanol. The pheromone concentrations were varied from 0.0, 0.1, 0.5, 1.0, 5.0 and 10.0 (v/v) in n-hexane. A. andreniformis foragers were repelled by 5.0 eicosane and 5.0 and 10.0 heptanol, while 0.5 and 1.0 1-eicosanol, 0.1, 0.5, 1.0, 5.0 and 10.0 eicosane, 0.5 and 1.0 heneicosane and 0.1, 0.5, 1.0, 5.0 and 10.0 2-heptanol repelled A. florea foragers. A. andreniformis foragers were attracted to 0.1 1-eicosanol, 10.0 eicosane, 1.0, 5.0 and 10.0 heneicosane and 0.1 2-heptanol. None of the pheromones were attractive to A. florea foragers. © 2011 IBRA

The applicability of forensic time since death estimation methods for buried bodies in advanced decomposition stages

Estimation of the postmortem interval in advanced postmortem stages is a challenging task. Although there are several approaches available for addressing postmortem changes of a (human) body or its environment (ecologically and/or biochemically), most are restricted to specific timeframes and/or individual and environmental conditions. It is well known, for instance, that buried bodies decompose in a remarkably different manner than on the ground surface. However, data on how established methods for PMI estimation perform under these conditions are scarce. It is important to understand whether and how postmortem changes are affected under burial conditions, if corrective factors could be conceived, or if methods have to be excluded for respective cases. We present the first multi-methodological assessment of human postmortem decomposition carried out on buried body donors in Europe, at the Amsterdam Research Initiative for Sub-surface Taphonomy and Anthropology (ARISTA) in the Netherlands. We used a multidisciplinary approach to investigate postmortem changes of morphology, skeletal muscle protein decomposition, presence of insects and other necrophilous animals as well as microbial communities (i.e., microbiomes) from August to November 2018 associated with two complete body exhumations and eight partial exhumations. Our results clearly display the current possibilities and limitations of methods for PMI estimation in buried remains and provide a baseline for future research and application