Male Behavior in \u3ci\u3eEvagetes Subangulatus\u3c/i\u3e (Hymenoptera: Pompilidae)

Males of Evagetes subangulatus patrolled primarily among shrubs in an area where females dug in soil. Twenty-nine individually-marked males were seen from 0 to 16 days after marking. They shared a home range space of about 400 m3. Although they did not exhibit territoriality, they chased and pounced upon one another and upon unmarked, conspecific males and females

Behavior at a Nesting Site and Prey of \u3ci\u3eCrabro Cribrellifer\u3c/i\u3e (Hymenoptera: Sphecidae)

In Michigan, Crabro cribrellifer tends to show nest clumping within a nest aggregation. Its nesting behavior is similar to that of other Crabro, and it preys on Neoitamus flavofemoratus (Diptera: Asilidae) on warm days in July. Miltogrammine flies Metopia campestris are active at the nesting site

Sodium ion interactions with aqueous glucose: Insights from quantum mechanics, molecular dynamics, and experiment

In the last several decades, significant efforts have been conducted to understand the fundamental reactivity of glucose derived from plant biomass in various chemical environments for conversion to renewable fuels and chemicals. For reactions of glucose in water, it is known that inorganic salts naturally present in biomass alter the product distribution in various deconstruction processes. However, the molecular-level interactions of alkali metal ions and glucose are unknown. These interactions are of physiological interest as well, for example, as they relate to cation-glucose cotransport. Here, we employ quantum mechanics (QM) to understand the interaction of a prevalent alkali metal, sodium, with glucose from a structural and thermodynamic perspective. The effect on B-glucose is subtle: a sodium ion perturbs bond lengths and atomic partial charges less than rotating a hydroxymethyl group. In contrast, the presence of a sodium ion significantly perturbs the partial charges of α-glucose anomeric and ring oxygens. Molecular dynamics (MD) simulations provide dynamic sampling in explicit water, and both the QM and the MD results show that sodium ions associate at many positions with respect to glucose with reasonably equivalent propensity. This promiscuous binding nature of Na + suggests that computational studies of glucose reactions in the presence of inorganic salts need to ensure thorough sampling of the cation positions, in addition to sampling glucose rotamers. The effect of NaCl on the relative populations of the anomers is experimentally quantified with light polarimetry. These results support the computational findings that Na + interacts similarly with a- and B-glucose

Lipid Composition of the Human Eye: Are Red Blood Cells a Good Mirror of Retinal and Optic Nerve Fatty Acids?

International audienceBACKGROUND: The assessment of blood lipids is very frequent in clinical research as it is assumed to reflect the lipid composition of peripheral tissues. Even well accepted such relationships have never been clearly established. This is particularly true in ophthalmology where the use of blood lipids has become very common following recent data linking lipid intake to ocular health and disease. In the present study, we wanted to determine in humans whether a lipidomic approach based on red blood cells could reveal associations between circulating and tissue lipid profiles. To check if the analytical sensitivity may be of importance in such analyses, we have used a double approach for lipidomics. METHODOLOGY AND PRINCIPAL FINDINGS: Red blood cells, retinas and optic nerves were collected from 9 human donors. The lipidomic analyses on tissues consisted in gas chromatography and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS). Gas chromatography did not reveal any relevant association between circulating and ocular fatty acids except for arachidonic acid whose circulating amounts were positively associated with its levels in the retina and in the optic nerve. In contrast, several significant associations emerged from LC-ESI-MS analyses. Particularly, lipid entities in red blood cells were positively or negatively associated with representative pools of retinal docosahexaenoic acid (DHA), retinal very-long chain polyunsaturated fatty acids (VLC-PUFA) or optic nerve plasmalogens. CONCLUSIONS AND SIGNIFICANCE: LC-ESI-MS is more appropriate than gas chromatography for lipidomics on red blood cells, and further extrapolation to ocular lipids. The several individual lipid species we have identified are good candidates to represent circulating biomarkers of ocular lipids. However, further investigation is needed before considering them as indexes of disease risk and before using them in clinical studies on optic nerve neuropathies or retinal diseases displaying photoreceptors degeneration

Flower Biology and Arthropod Associates of Lilium Philadelphicum

Flowers of Lilium philadelphicum bear pollen mostly during the first day of bloom and nectar on an irregular schedule during the first six days of anthesis. Pollination experiments suggest that this species must cross-pollinate to produce seeds. Butterflies which transfer pollen of this lily with their wings and pollinating sweat bees show suboptimal foraging movements on individual flowers. Mirid bugs, ants, and other butterflies steal nectar. Tortricid larvae consume flower parts

An investigation of the polymorphic habits of Polygonum amphibian and P. coccineum.

http://deepblue.lib.umich.edu/bitstream/2027.42/52377/1/808.pdfDescription of 808.pdf : Access restricted to on-site users at the U-M Biological Station

Mating Behavior in Halictine Bees (Hymenoptera: Halictidae): I, Patrolling and Age-specific Behavior in Males

Males of 12 species of bees in both tribes of Halictinae (Halictidae) lived up to 62 days in captivity, patrolled when 3 to 62 days old, and mated when 3 to 18 days old. Patrolling by male bees is defined as the repeated flying of non-feeding males among landmarks which may be rendezvous places (locations where males are likely to find females); these males usually confine patrolling to particular topographical areas. In nature patrolling halictine males fly in zig-zag paths at nesting sites and around plants and in addition to conspecific females, they are attracted to various female-sized objects. In the laboratory these males exhibit non-sequential patrolling, flying among landmarks in no particular order, and they commonly add and delete landmarks from patrolled areas. Males of Augochlora pura and Agapostemon splendens exhibit topographical orientation in that they search for landmarks removed from their patrolled areas. When alighted, halictine males frequently groom, feed, lingualate nectar, and rotate their bodies. They sleep solitarily or gregariously, depending on the species

Robbing of Exotic Plants by Introduced Carpenter and Honey Bees in Hawaii, with Comparative Notes

In Hawaii, a carpenter bee (Xylocopa sonorina) and the honey bee (Apis mellifera) use floral perforations to obtain nectar. With its maxillae, X. sonorina perforates corollas and calyces of introduced plant species; in corollas of different lengths and diameters, the perforations made are significantly different in length. Through these perforations, X. sonorina imbibes nectar without pollinating the flowers. Old and New World Xylocopa spp. perforate the flowers of at least 22 families. Apis mellifera obtains nectar through perforations made by X . sonorina. Elsewhere in the world, A. mellifera uses previously made perforations in flowers to obtain nectar from at least 10 plant families. These bees are robbers of some plants in that they take floral provisions in ways that are unlikely to effect pollination

Individually Distinctive Odors in an Invertebrate

Males of Lasioglossum zephyrum demonstrated that females have odors which are characteristic of individuals. In a sequence of presentations of odors of individual females, male response toward odor of a given female decreased with time. However, renewed response resulted from the presentation of odor of another female. Furthermore males of this species are capable of remembering individual odors of females in nature, since in the laboratory they remained habituated to odors of individual females for at least 60-135 min

Occupancy by Hylaeus of Subterranean Halictid Nests (Hymenoptera: Apoidea)

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