Vertical stratification of selected Hymenoptera in a remnant forest of the Po Plain (Italy, Lombardy) (Hymenoptera: Ampulicidae, Crabronidae, Sphecidae)

Communities of the canopy of temperate forests are still relatively unexplored. Furthermore, very little is known on how vertical stratification for some insect groups is related to biological strategies. In this study, we investigated the community composition of both canopy and understory of the families Ampulicidae, Crabronidae and Sphecidae (Hymenoptera) of the Natural Reserve of "Bosco della Fontana", a remnant lowland forest in northeastern Italy. Observed patterns in vertical stratification have been related to species foraging habits. Our study reveals that the bulk of the community of Spheciformes of the understory consists of species predating dipterans and spiders, while species associated with the canopy are mainly predators of sap-sucking honeydew producers and epiphyte grazers, like aphids, thrips, and barkflies. Comparing the communities of canopy and understory may lead to a better understanding of species ecology and provides useful information to forest managers

The corrosion of magnesium: the influence of inorganic ions and selected organic compounds

Magnesium (Mg) and its alloys have been extensively investigated for engineering, energy storage, and biomedical applications owing to their suitable properties. However, the intrinsic high corrosion rate of Mg alloys restricts their general applicability. In the recent years, a number of new-type alloys, surface modification methods, processing routes, and corrosion inhibitors have been developed in order to obtain Mg materials with suitable anticorrosion properties that meet all requirements for the targeted application. For this sake, corrosion tests are frequently employed to evaluate the corrosion resistance and degradation behavior of the investigated materials prior to real application. However, this is complicated by the fact that there are no generally accepted protocols for Mg corrosion tests, especially for testing Mg as implant biomaterials. Until now, a variety of media has been used in these tests and the applicability of these media has not been fully described until now impeding the comparability of results from different research groups. In this thesis, the influence of media components, (e.g. inorganic ions, synthetic pH buffer and selected organic compounds) on the degradation of Mg is systematically studied to provide more insight into the influence of the media composition on Mg corrosion tests. The results show that the synthetic pH buffer (Tris/HCl) accelerates Mg corrosion in simulated body fluid (SBF). Its acceleration effect can be attributed to three factors: the consumption of OH- (caused by the buffering effect), which is needed for the formation of corrosion products, the complexation ability of Tris for Ca2+ and Mg2+, and the increased concentration of Cl-. Moreover, in SBF without synthetic pH buffer, the synergy between Ca2+, carbonates and phosphates plays a significant role in the corrosion protection of Mg. In Tris-free electrolytes, the corrosion rate of Mg in SBF (with Ca2+, HCO3- and HPO42-) is significantly lower than that in the electrolytes missing one of the three ions. The trio of ions leads to the continuous growth of the protective co-precipitation layer above the normal MgO/Mg(OH)2 corrosion products on corroded Mg surface and then slows down the Mg corrosion. In terms of bio-relevant organic compounds, amino acids, vitamins, and saccharides at low concentration have no critical influence on Mg corrosion in NaCl solution and SBF electrolyte. The antibiotics, penicillin and streptomycin, at operating concentration (around 10-4 M), also have no significant influence on Mg corrosion in minimum essential medium (MEM) and SBF. While streptomycin, as a Ca2+ chelating agent, at higher concentration (10-2 M and 10-3 M) increases the corrosion rate of Mg in MEM and SBF, the importance of free Ca2+ concentration on the protection of Mg corrosion in HCO3- and HPO42--containing media is emphasized. In addition, the influence of albumin on Mg corrosion is investigated. The results demonstrated that the influence of albumin on Mg corrosion is susceptible to the albumin sources, test methods, and test conditions. Its influencing mechanism can be summarized in three aspects, adsorption, Ca2+/Mg2+ chelation and pH buffering effects. The results of this work highlight the significant influence of the composition of the used media on Mg corrosion tests. Based on these finding, a general discussion about the advantages, shortcomings, and applicability of the commonly used media is provided and potential medium selection criteria for Mg corrosion tests for various research purposes are suggested. The systematic investigation of the corrosion behavior of Mg in pseudophysiological media presented in this work provides a deeper understanding of the underlying mechanism and lays the foundation for the standardization of the corresponding testing protocols

A single photon produces general W state of N qubits and its application

Based on the Wu's scheme[1], We prepare the general N-qubit W state. We find that the concurrence of two qubits in general N-qubit W state is only related to their coefficients and we successfully apply the general N-qubit W state to quantum state transfer and quantum state prepare like that in two-qubit system

New constraints on cosmic polarization rotation from the ACTPol cosmic microwave background B-Mode polarization observation and the BICEP2 constraint update

Recently ACTPol has measured the cosmic microwave background (CMB) B-mode and E-mode polarizations and obtained TE, EE, BB, TB and EB power spectra in the multipole range 225-8725. In our previous paper (Ap. J. 792 (2014) 35 [Paper I]), we have analyzed jointly the results of three experiments on the CMB B-mode polarization -- SPTpol, POLARBEAR and BICEP2 to include in the model, in addition to the gravitational lensing and the inflationary gravitational waves components, also the fluctuation effects induced by the cosmic polarization rotation (CPR), if it exists within the upper limits at the time. In this paper, we fit both the mean CPR angle and its fluctuation from the new ACTPol data, and update our fitting of CPR fluctuations using BICEP2 data taking the new Planck dust measurement results into consideration. We follow the method of Paper I. The mean CPR angle is constrained from the EB correlation power spectra to || < 14 mrad (0.8{\deg}) and the fluctuation (rms) is constrained from the BB correlation power spectra to 1/2 < 29.3 mrad (1.68{\deg}). Assuming that the polarization angle of Tau A does not change from 89.2 to 146 GHz, the ACTPol data give = 1.0 {\pm} 0.63{\deg}. These results suggest that the inclusion of the present ACTPol data is consistent with no CPR detection. With the new Planck dust measurement, we update our fits of the BICEP2 CPR fluctuation constraint to be 32.8 mrad (1.88{\deg}). The joint ACTpol-BICEP2-POLARBEAR CPR fluctuation constraint is 23.7 mrad (1.36{\deg}).Comment: 15 pages, 2 figures, 2 tables, version to match the accepted submission to ApJ. Unfortunately there is a sign error in equation (6b). This propagated to equations (7b) and (8a) and to the results for \alpha_\beta. The errors in the last raw of Table 1 had been overestimated and correcte

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Studying the impact of microtopography on irrigation performance is important for improving the management of basin irrigation systems. However, the limitation of field experiments will restrict the studies on the impact of microtopography spatial variability on basin irrigation performance. Thus, firstly this paper analyzed the spatial variability characteristics of field-measured Surface Relative Elevations (SRE). The correlations between the field geometry parameters and the spatial variability characteristics of SRE were evaluated, and the estimation methods for parameters of the semi-variogram of SRE were determined. Secondly, a microtopography stochastic generating model was built up based on the Monte-Carlo and the Kriging interpolation techniques. Lastly, the effect of spatial variability of microtopography on the performance of basin irrigation was evaluated by using of the numerical simulation model. Results showed that the microtopography undulation degree and the spatial distribution difference of undulation location had obvious effect on the basin irrigation performance. The average irrigation depth (Z'avg), corresponding to the water just cover the whole basin surface is increased while the irrigation application efficiency (Ea) and the irrigation uniformity (CU) is decreased when the field elevation non-uniformity, measured by the standard deviation of SRE (Sd) is increased. The effect of spatial distribution of undulation location on the irrigation performance was dependent upon the microtopography undulation degree, when Sd is less than 2cm the impacts can be neglected, while Sd is greater than 2cm, the influence should be considered

Detailed morphological descriptions of the immature stages of the ant parasite Microdon mutabilis (Diptera: Syrphidae: Microdontinae) and a discussion of its functional morphology, behaviour and host specificity

The myrmecophilous immature stages of hover flies of the genus Microdon Meigen, 1803 (Diptera, Syrphidae) are still poorly known and only about 15 species were previously incompletely described and/or illustrated using light microscopy based on occasional findings mainly of pupae and third instar larvae. The exceptional finding of a large number of second and third instar larvae and pupae (159 specimens) of Microdon mutabilis (Linnaeus, 1758) inside the nest of a new host species, Formica cunicularia Latreille,1798, enabled us to rear them and obtain a great number of eggs and first instar larvae. We filmed and described the feeding behaviour and locomotion of these highly derived slug-like larvae. Combining light, fluorescence and scanning electron (SEM) microscopy, we describe in detail and illustrate the external features of all the immature stages of M. mutabilis (eggs, larvae and pupae). Covering the entire chorion of the egg is a peculiar microsculpture composed of volcano-like processes. The three larval instars strongly differ from each other, especially at the level of the shape of the body, the posterior spiracular tubercle and the cephaloskeleton. SEM microscopy was used to describe in detail the microsculpture, sensorial structures, spiracles and cephalic appendages of larvae and pupae. Fluorescence microscopy was used to reveal the exceptional presence of resilin in the external layer of the posterior spiracular tubercle in first instar larvae. The possible functional significance of these structures is discussed

Computational modeling of degradation process of biodegradable magnesium biomaterials

Despite the advantages of using biodegradable metals in implant design, their uncontrolled degradation and release remain a challenge in practical applications. A validated computational model of the degradation process can facilitate the tuning of implant biodegradation by changing design properties. In this study, a physicochemical model was developed by deriving a mathematical description of the chemistry of magnesium biodegradation and implementing it in a 3D computational model. The model parameters were calibrated using the experimental data of hydrogen evolution by performing a Bayesian optimization routine. The model was validated by comparing the predicted change of pH in saline and buffered solutions with the experimentally obtained values from corrosion tests, showing maximum 5% of difference, demonstrating the model's validity to be used for practical cases