Determination of Flower Constancy in Bombus atratus Franklin and Bombus bellicosus Smith (Hymenoptera: Apidae) through Palynological Analysis of Nectar and Corbicular Pollen Loads

The flower constancy (the visit to a single plant species during a foraging trip) in pollinator insects is a theme widely discussed in behavioral ecology and has an important implication in the evolution of angiosperms. This behavior was studied in the bumblebees Bombus atratus Franklin and Bombus bellicosus Smith through palynological analysis of the nectar and pollen loads of individuals captured while foraging in a restricted area. In both species, there were more individuals with constant flights than with non-constant ones, although in the nectar loads of B. atratus there were no significant differences between individuals with each flight types. It was verified that the nectar loads of the individuals that made either constant or non-constant flights did not differ in the number of pollen grains they contained. Considering this measurement as an estimate for flight duration, the results would indicate that the probability of changing between plant species during nectar collection is independent of the foraging trip duration. In both species, most individuals who collected nectar and/or pollen from more than one plant species visited just two plant species. In these cases, the pollen of one plant species was predominant. In the bumblebees in which it was possible to analyze nectar and pollen loads, the botanical origin of both resources was the same or they shared the principal species (with the exception of two individuals), showing that bumblebees do not often use a botanical source in an exclusive way to collect nectar and another to collect pollen.

Molecular dissociation in the presence of catalysts: interpreting bond breaking as a quantum dynamical phase transition

In this work we show that molecular chemical bond formation and dissociation in the presence of the d-band of a metal catalyst can be described as a quantum dynamical phase transition (QDPT). This agrees with DFT calculations that predict sudden jumps in some observables as the molecule breaks. According to our model this phenomenon emerges because the catalyst provides for a non-Hermitian Hamiltonian. We show that when the molecule approaches the surface, as occurs in the Heyrovsky reaction of H2, the bonding H2 orbital has a smooth crossover into a bonding molecular orbital built with the closest H orbital and the surface metal d-states. The same occurs for the antibonding state. Meanwhile, two resonances appear within the continuous spectrum of the d-band, which are associated with bonding and antibonding orbitals between the furthest H atom and the d-states at the second metallic layer. These move toward the band center, where they collapse into a pure metallic resonance and an almost isolated H orbital. This phenomenon constitutes a striking example of the non-trivial physics enabled when one deals with non-Hermitian Hamiltonian beyond the usual wide band approximation.

Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with [Formula: see text] eV by analyzing cosmic rays with energies above [Formula: see text] eV arriving within an angular separation of approximately 15[Formula: see text]. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.

Hydrogen evolution reaction on palladium multilayers deposited on Au(111): a theoretical approach

We have investigated the electrocatalytic properties of multilayers of Pd epitaxially deposited on Au(111). In contrast to the numerous previous works in this area, we have focused on the kinetics of the electrochemical step for hydrogen adsorption (Volmer reaction) and determined its energies of activation. We have used a combination of density functional theory calculations and our own theory of electrocatalysis, which allows us to investigate the systems in an electrochemical environment. Contrary to our previous work with a submonolayer of Pd in Au(111), the activation barrier for the hydrogen adsorption process from proton is very low or almost zero for all bimetallic systems investigated. It is about 0.2 eV for pure Pd(111). In the case of two layers of Pd on Au(111) containing absorbed hydrogen in the subsurface, the adsorption free energy is less negative and the barrier lower than for the other investigated systems. This is in agreement with experimental data that shows a larger activity for hydrogen oxidation with hydride Pd systems.

First measurement of neutrino and antineutrino coherent charged pion production on argon

We report on the first cross section measurements for charged current coherent pion production by neutrinos and antineutrinos on argon. These measurements are performed using the ArgoNeuT detector exposed to the NuMI beam at Fermilab. The cross sections are measured to be 2.6(-1.0)(+1.2)(stat)(-0.4)(+0.3)(syst)×10(-38)  cm(2)/Ar for neutrinos at a mean energy of 9.6 GeV and 5.5(-2.1)(+2.6)(stat)(-0.7)(+0.6)(syst)×10(-39)  cm(2)/Ar for antineutrinos at a mean energy of 3.6 GeV.

Application of cell encapsulation for controlled delivery of biological therapeutics

Cell microencapsulation technology is likely to have an increasingly important role in new approaches rather than the classical and pioneering organ replacement. Apart from becoming a tool for protein and morphogen release and long-term drug delivery, it is becoming a new three-dimensional platform for stem cell research. Recent progress in the field has resulted in biodegradable scaffolds that are able to retain and release the cell content in different anatomical locations. Additional advances include the use biomimetic scaffolds that provide greater control over material-cell interactions and the development of more precise encapsulated cell-tracking systems. This review summarises the state of the art of cell microencapsulation and discusses the main directions and challenges of this field towards the controlled delivery of biological therapeutics.

Magnetic ionic liquids: synthesis, properties and applications

Magnetic ionic liquids are room temperature ionic liquids, which have paramagnetic properties by themselves without the need of adding magnetic particles.

Abstract P2-16-09: Retrospective analysis of long-term survivors with HER2+ metastatic breast cancer (MBC) treated with trastuzumab in a community setting

Background: The median survival for patients (pts) receiving trastuzumab (T) in the metastatic setting is approximately 3 years. There are limited data on real world use and outcomes in T treated pts who live longer than 3 years. The objective of this study was to identify and characterize pts with HER2+ MBC who initiated treatment with T (alone or in combination) in a community setting and to determine their treatment patterns and outcomes, including duration of treatment, overall survival (OS) and time to permanent discontinuation of T. Methods: A retrospective observational study was performed using the IKnowMed electronic medical record (EMR) used by the US Oncology Network with the primary time period of 2007 through Dec. 2012. Eligible pts had at least 2 visits at practice locations with full EMR capability. Pts on T when the EMR was implemented had chart review to determine the dates of diagnosis and start of T treatment. Results: The study population included 1856 women with HER2+ MBC who started T (alone or in combination with chemotherapy or hormonal therapy); 873 presented with MBC and 983 developed recurrence following diagnosis of early-stage disease. The median age was 58, range 23 to 96, 59% had ER+ cancer, 64% were postmenopausal and 35% had multiple sites of disease at presentation. Median OS for the entire group was 40.9 months and the median time to permanent discontinuation of T was slightly less, at 39.9 months. Interestingly, the median OS and duration of T use were similar in the recurrent MBC population and in the population who presented with de novo MBC. The proportion of pts receiving T and OS by year are presented (Table). Thirty-two percent of pts are still alive at 6 years, with 17% continuing to receive T.

Outcomes of 1856 Patients Treated with TrastuzumabYear1356Pts still receiving T (%)82%53%27%17%OS (%)84%54%36%32%

Ongoing analysis will evaluate whether there are pt and treatment characteristics that may predict for longer term OS. Conclusions: Using an EMR database we identified 1856 women with HER2+ MBC who initiated treatment with T (alone or in combination) with one third still alive at 5 years and 27% still on T. Future research that focuses on understanding the characteristics of this population can potentially improve care for women with HER2+ MBC with T and newer anti-HER2 agents.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-09.

Oesophageal involvement in bullous pemphigoid

Bullous pemphigoid (BP) is an acquired autoimmune disease that predominantly affects older people. Mucosal involvement is rare in BP. We report an unusual case of an elderly patient with BP with involvement of the oesophagus presenting as gastrointestinal (GI) bleeding. Although mucosal involvement is typically rare in BP, it should be considered in the differential diagnosis of GI bleeding in patients affected with the disease.