Lethal and sublethal effects of azadirachtin on the bumblebee Bombus terrestris (Hymenoptera: Apidae)

Background: Lethal and sublethal effects of azadirachtin were studied on Bombus terrestris via oral exposure in the laboratory to bring out the potential risks of the compound to this important pollinator.Results: Microcolonies chronically exposed to azadirachtin via treated sugar water during 11 weeks in the laboratory exhibited a high mortality ranging from 32 to 100 % with a range of concentrations between 3.2 and 320 mg litre-1. No reproduction was scored at concentrations higher than 3.2 mg litre-1. At 3.2 mg litre-1, azadirachtin significantly inhibited the egg laying and, consequently, the production of drones during 6 weeks. When azadirachtin was tested under an experimental setup in the laboratory where bumblebees need to forage for food, the sublethal effects were stronger as the numbers of drones were reduced already with a concentration of 0.64 mg litre-1. Besides, a negative correlation was found between the body mass of male offspring and azadirachtin concentration.Conclusion: Azadirachtin can affect B. terrestris with a range of sublethal effects. This study confirms the need to test compounds on their safety, especially when they have to perform complex tasks such as foraging.Keywords: chronic oral exposure, insect growth regulator (IGR), neem, repellence effect, reproductio

Extended morphometric analysis of neuronal cells with Minkowski valuations

Minkowski valuations provide a systematic framework for quantifying different aspects of morphology. In this paper we apply vector- and tensor-valued Minkowski valuations to neuronal cells from the cat's retina in order to describe their morphological structure in a comprehensive way. We introduce the framework of Minkowski valuations, discuss their implementation for neuronal cells and show how they can discriminate between cells of different types.Comment: 14 pages, 18 postscript figure

Reduced-risk insecticides in Neotropical stingless bee species: impact on survival and activity

Background: As honeybees are the main pollinator species subject to an intense research regarding effects of pesticides, other ecologically important native bee pollinators have received little attention in ecotoxicology and risk assessment of pesticides in general, and insecticides in particular, some of which are perceived as reduced-risk compounds. Here the impact of three reduced-risk insecticides – azadirachtin, spinosad, and chlorantraniliprole – was assessed in two species of stingless bees, Partamona helleri and Scaptotrigona xanthotrica, which are important native pollinators in Neotropical America. The neonicotinoid imidacloprid was used as a positive control.Results: Spinosad exhibited high oral and contact toxicities in adult workers of both species at the recommended label rates, with median survival times (LT50s) ranging from 1 to 4 h, whereas these estimates were below 15 min for imidacloprid. Azadirachtin and chlorantraniliprole exhibited low toxicity at the recommended label rates, with negligible mortality that did not allow LT50 estimation. Sublethal behavioral assessments of these two insecticides indicated that neither one of them affected the overall group activity of workers of the two species. However, both azadirachtin and chlorantraniliprole impaired individual flight take-off of P. helleri and S. xanthotrica worker bees, which may compromise foraging activity, potentially leading to reduced colony survival.Conclusion: These findings challenge the common perception of non-target safety of reduced-risk insecticides and bioinsecticides, particularly regarding native pollinator species.Keywords: behavioral impact; biopesticides; colony and individual level effects; native bee pollinators; sublethal effect

Quantum circuits measuring weak values, Kirkwood--Dirac quasiprobability distributions, and state spectra

Weak values and Kirkwood--Dirac (KD) quasiprobability distributions have been independently associated with both foundational issues in quantum theory and advantages in quantum metrology. We propose simple quantum circuits to measure weak values, KD distributions, and spectra of density matrices without the need for post-selection. This is achieved by measuring unitary-invariant, relational properties of quantum states, which are functions of Bargmann invariants, the concept that underpins our unified perspective. Our circuits also enable experimental implementation of various functions of KD distributions, such as out-of-time-ordered correlators (OTOCs) and the quantum Fisher information in post-selected parameter estimation, among others. An upshot is a unified view of nonclassicality in all those tasks. In particular, we discuss how negativity and imaginarity of Bargmann invariants relate to set coherence.Comment: 23+7 pages, 7+5 figures. v2: new sections 2.3, 2.4, 3, 4.5, revised structure. Comments are welcome

Determination of myricetin derivatives in Chrysobalanus icaco L. (Chrysobalanaceae)

RESUMO: "Determinação de derivados de miricetina em Chrysobalanus icaco L. (Chrysobalanaceae)". A fração fl avonoídica do extrato hidroalcoólico de folhas de Chrysobalanus icaco L. (Chrysobalanaceae), que são largamente utilizadas na medicina tradicional do Norte do Brasil para controlar a glicemia de pacientes diabéticos, foi caracterizada. Miricetina-3-Oglucuronídeo (miricitrina) e quercitrina, entre outros derivados de miricetina minoritários, foram evidenciados por análises com sistemas CLAE/DAD e CLAE/EM. Unitermos: Chrysobalanus icaco, Chrysobalanaceae, miricetina, medicina tradicional, diabetes. ABSTRACT: The fl avonoidic fraction composition of the hydroalcoholic extract of Chrysobalanus icaco L. (Chrysobalanaceae) leaves, which are largely used in the traditional medicine in Northern Brazil to control the glycaemia of diabetic patients, was characterised. Myricetin 3-O-glucuronide (miricitrin) and quercitrin, among other minor myricetin derivatives, were evidenced by HPLC/ DAD and HPLC/MS analysis

Quantum circuits for measuring weak values, Kirkwood–Dirac quasiprobability distributions, and state spectra

Weak values and Kirkwood–Dirac (KD) quasiprobability distributions have been independently associated with both foundational issues in quantum theory and advantages in quantum metrology. We propose simple quantum circuits to measure weak values, KD distributions, and spectra of density matrices without the need for post-selection. This is achieved by measuring unitary-invariant, relational properties of quantum states, which are functions of Bargmann invariants, the concept that underpins our unified perspective. Our circuits also enable experimental implementation of various functions of KD distributions, such as out-of-time-ordered correlators (OTOCs) and the quantum Fisher information in post-selected parameter estimation, among others. An upshot is a unified view of nonclassicality in all those tasks. In particular, we discuss how negativity and imaginarity of Bargmann invariants relate to set coherence

Analytical method validation for in vitro permeation of Calendula officinalis L. gel

The objective of this study was to evaluate preliminary stability, as well as to validate an analytical method for in vitro skin permeation study of a gel containing tincture of Calendula officinalis L., aiming at the implementation and consolidation of methodologies to be used as prototype for future development of herbal medicine in the Brazilian Amazon region. The gel showed a satisfactory result during the assessment of its preliminary stability considering that the formulation remained stable throughout cycles at temperatures of 45 °C and 25 °C. Parameters obtained in the validation of the analytical method presented satisfactory results for specificity, linearity (r > 0.99), precision (intra-day and inter-day) with relative standard deviation values (R.S.D. %) below the required maximum of 5 %. Accuracy and robustness were consistent with both the objectives of the work and recommendations of the existing laws, providing the reliability of the data obtained during the skin permeation study, evidenced by the gel tendency to promote the permeation of flavonoids, expressed in rutin, through models of synthetic and biological membrane. However, it was observed that the gel had a higher permeability ratio through synthetic membrane, due to greater cumulative mass of rutin quantified after permeation.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Indication for the disappearance of reactor electron antineutrinos in the Double Chooz experiment

The Double Chooz Experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. A ratio of 0.944 $\pm$ 0.016 (stat) $\pm$ 0.040 (syst) observed to predicted events was obtained in 101 days of running at the Chooz Nuclear Power Plant in France, with two 4.25 GW$_{th}$ reactors. The results were obtained from a single 10 m$^3$ fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 measurement as an anchor point. The deficit can be interpreted as an indication of a non-zero value of the still unmeasured neutrino mixing parameter \sang. Analyzing both the rate of the prompt positrons and their energy spectrum we find \sang = 0.086 $\pm$ 0.041 (stat) $\pm$ 0.030 (syst), or, at 90% CL, 0.015 $<$ \sang $\ <$ 0.16.Comment: 7 pages, 4 figures, (new version after PRL referee's comments

Physicochemical and phytochemical control of Arrabidaea chica (H. & B.) Verlot leaf powder and standardized tincture

The quality control of herbal drugs and their intermediates is essential, especially when they are used as feedstock for medicine development. This study aimed at applying the methodologies established by Brazilian legislation for the development of parameters concerning the characterization and quality control of leaf powder and tincture of Arrabidaea chica (H & B) Verlot. Known as cipó-pau (vinestick), carajeru, pariri, among others, it presents antifungal activity and is used in several diseases such as mycosis and ringworm. The physico-chemical characteristics of the plant drug. The phytochemical screening of the t inc tur e indi cat ed the pr e s enc e of r educ ing sugar s , anthocyanidins , anthocyanins , anthraquinones, steroids, triterpenoids, phenols, flavanonols, flavanols, flavanones, saponins and tannins catechists. HPLC chromatograms showed peaks at 275 nm and 290 nm, with Rt of 8.91 and 13.57 min, whose corresponding spectra showed absorption maxima which is characteristic of flavones and biflavonols -283 nm and 334 nm. Some metabolites found in the phytochemical screening and detected by HPLC may justify the popular use of A. chica as antimicrobial and antifungal medicine.Colegio de Farmacéuticos de la Provincia de Buenos Aire