Search results for "bee"
showing 10 items of 628 documents
Fate of the herbicides glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron in two Finnish arable soils.
2006
The fate of five herbicides (glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron) was studied in two Finnish sugar beet fields for 26 months. Soil types were sandy loam and clay. Two different herbicide-tolerant sugar beet cultivars and three different herbicide application schedules were used. Meteorological data were collected throughout the study and soil properties were thoroughly analysed. An extensive data set of herbicide residue concentrations in soil was collected. Five different soil depths were sampled. The study was carried out using common Finnish agricultural practices and represents typical sugar beet cultivation conditions in Finland. The overall obse…
Morphological variability in and distributional data on phaleria bimaculata populations from islands of the central mediterranean area
2011
This study aimed to collect new taxonomic and distribution data on Phaleria bimaculata (L.) (Coleoptera Tenebrionidae) from Sicily (southern Italy), the circum-Sicilian islands and the Maltese archipelago. Particular attention was paid to the diagnostic morphological features observed in the populations sampled, focusing on the subspecies Phaleria bimaculata marcuzzii Aliquò. P. bimaculata individuals were collected from 20 different locations, of which 2 were located in the Sicilian mainland, 9 in circum-Sicilian islands and 9 in the Maltese Islands. In addition, four Phaleria acuminata Kuster populations were also recorded along southern Sicilian shores. The two Phaleria species were neve…
Analytical procedure elaboration of total flavonoid content determination and antimicrobial activity of bee bread extracts
2019
Sixteen ethanolic extracts were obtained from seven different bee bread samples. The total flavonoid content in the extracts was determined by aluminium-chloride method and was in the range of 8.3 mg/L ± 6.24% to 195.3 mg/L ± 1.35% and 28.8 mg/L ± 19.33% to 603.3 mg/L ± 4.64% with reference to quercetin and rutin, respectively. The relative standard deviations (RSD) for parallel measurements for the calibration curves of quercetin dehydrate and rutin trihydrate were in the range of 0.51% to 9.39% and 5.02% to 19.91%, respectively. The RSD for parallel measurements for the extracts with reference to quercetin dihydrate and rutin trihydrate were in the range of 0.23% to 11.64% and 4.64% to 19…
Phospha-Fischer Carbenes: Synthesis, Structure, Bonding, and Reactions of Pd(0)− and Pt(0)−Phosphenium Complexes
2009
The analogy between cationic group 10 metal−phosphenium complexes and Fischer carbenes has been formalized through structural and reactivity studies and by energy decomposition analysis (EDA) of the M−P bond. The studied compounds were the three-coordinate, 16-electron species [(NHPMes)M(PPh3)2]OTf (M = Pt (1) and Pd (2); [NHPMes]+ is the N-heterocyclic phosphenium (NHP) cation, [tiebar above startPN(2,4,6-Me3-C6H2)CH2CH2tiebar above endN(2,4,6-Me3-C6H2)]+, OTf = trifluoromethanesulfonate); these were made by reaction of [NHPMes]OTf with M(PPh3)4. The metal−phosphenium bond in both compounds was dominated by metal-to-ligand π-donation. This differed from the M−C bonds in the analogous N-het…
Electron spectra in forbidden β decays and the quenching of the weak axial-vector coupling constant gA
2017
Evolution of the electron spectra with the effective value of the weak axial-vector coupling constant ${g}_{\mathrm{A}}$ was followed for 26 first-, second-, third-, fourth- and fifth-forbidden ${\ensuremath{\beta}}^{\ensuremath{-}}$ decays of odd-$A$ nuclei by calculating the involved nuclear matrix elements (NMEs) in the framework of the microscopic quasiparticle-phonon model (MQPM). The next-to-leading-order terms were included in the $\ensuremath{\beta}$-decay shape factor of the electron spectra. The spectrum shapes of third- and fourth-forbidden nonunique decays were found to depend strongly on the value of ${g}_{\mathrm{A}}$, while first- and second-forbidden decays were mostly unaff…
Excited states in 31S studied via beta decay of 31Cl
2006
The beta decay of 31Cl has been studied with a silicon detector array and a HPGe detector at the IGISOL facility. Previously controversial proton peaks have been confirmed to belong to 31Cl and a new proton group with an energy of 762(14) keV has been found. Proton captures to this state at 6921(15) keV in 31S can have an effect on the reaction rate of 30P(p,γ) in ONe novae. Gamma rays of 1249.1(14) keV and 2234.5(8) keV corresponding to the de-excitations of the first two excited states in 31S have been measured. No beta-delayed protons from the IAS have been observed. peerReviewed
Synchronized rotation in swarms of magnetotactic bacteria.
2017
Self-organizing behavior has been widely reported in both natural and artificial systems, typically distinguishing between temporal organization (synchronization) and spatial organization (swarming). Swarming has been experimentally observed in systems of magnetotactic bacteria under the action of external magnetic fields. Here we present a model of ensembles of magnetotactic bacteria in which hydrodynamic interactions lead to temporal synchronization in addition to the swarming. After a period of stabilization during which the bacteria form a quasiregular hexagonal lattice structure, the entire swarm begins to rotate in a direction opposite to the direction of the rotation of the magnetic …
Uniform climate sensitivity in tree-ring stable isotopes across species and sites in a mid-latitude temperate forest.
2014
Tree-ring stable isotopes, providing insight into drought-induced eco-physiological mechanisms, are frequently used to reconstruct past changes in growing season temperature and precipitation. Their climatic response is, however, still not fully understood, particularly for data originating from non-extreme, mid-latitude environments with differing ecological conditions. Here, we assess the response of δ(13)C, δ(18)O and tree-ring width (TRW) from a temperate mountain forest in the Austrian pre-Alps to climate and specific drought events. Variations in stem growth and isotopic composition of Norway spruce, common beech and European larch from dry, medium and moist sites are compared with re…
General principles in motion vision: Color blindness of object motion depends on pattern velocity in honeybee and goldfish
2011
AbstractVisual systems can undergo striking adaptations to specific visual environments during evolution, but they can also be very “conservative.” This seems to be the case in motion vision, which is surprisingly similar in species as distant as honeybee and goldfish. In both visual systems, motion vision measured with the optomotor response is color blind and mediated by one photoreceptor type only. Here, we ask whether this is also the case if the moving stimulus is restricted to a small part of the visual field, and test what influence velocity may have on chromatic motion perception. Honeybees were trained to discriminate between clockwise- and counterclockwise-rotating sector disks. S…
The effects of short-term glyphosate-based herbicide exposure on insect gene expression profiles
2023
Glyphosate-based herbicides (GBHs) are the most frequently used herbicides worldwide. The use of GBHs is intended to tackle weeds, but GBHs have been shown to affect the life-history traits and antioxidant defense system of invertebrates found in agroecosystems. Thus far, the effects of GBHs on detoxification pathways among invertebrates have not been sufficiently investigated. We performed two different experiments—1) the direct pure glyphosate and GBH treatment, and 2) the indirect GBH experiment via food—to examine the possible effects of environmentally relevant GBH levels on the survival of the Colorado potato beetle (Leptinotarsa decemlineata) and the expression profiles of their deto…