Contributors: Ming Bai, Rolf Georg Beutel, Klaus-Dieter Klass, Weiwei Zhang, Xingke Yang, Benjamin Wipfler
... A new insect species (†Alienopterus brachyelytrus Bai, Beutel, Klass, Wipfler et Zhang gen. et sp. nov.) of a new order and family is described, based on a single male embedded in Cretaceous Burmese amber (ca. 99Ma). Unusual characters are shortened forewings combined with fully developed, operational hindwings, similar as in Dermaptera, and specialized attachment pads otherwise only found in mantophasmatodeans (heelwalkers). A cladistic analysis suggests a placement as sister to Mantodea, supported by a profemoral brush and other characters. The male genitalia show the same pattern in both groups. Specialized features are the unusual flight apparatus, attachment structures adapted for locomotion on leaves, and a dense profemoral setation suitable for catching small prey. †Alienopterus was apparently able to fly and likely a predator of small arthropods in bushes or trees. An impressive radiation of Mantodea started in similar habitats at least 35Ma later in the early Cenozoic. In contrast, †Alienopterus was an evolutionary dead end in the roach–mantis transition zone.
Contributors: Giorgio Rizzi, Meredith E. Lodge, Kelly R. Tan
... Operant behavioral tasks for animals have long been used to probe the function of multiple brain regions (i.e., understanding the role of dopamine in electrical brain stimulation reward , or determining the rewarding properties of feeding oriented brain pathways ). The recent development of tools and techniques has opened the door to refine the answer to these same questions with a much higher degree of specificity and accuracy, both in biological and spatial-temporal terms [3,4]. A variety of systems designed to test operant behavior are now commercially available, but have prohibitive costs. Here, we provide a low-cost alternative to a nose poke system for mice. Adapting a freely available sketch for ARDUINO boards, in combination with an in-house built PVC box and inexpensive electronic material we constructed a four-port nose poke system that detects and counts port entries. To verify the applicability and validity of our system we tested the behavior of DAT-CRE transgenic mice injected with an adeno-associated virus to express ChannelRhodopsin 2 in the Ventral tegmental area (VTA) and used the BNC output to drive a blue laser coupled to a fiber implanted above the VTA. Over 6days, mice perform as it has been reported previously  exhibiting a remarkable preference for the port that triggers optogenetic stimulation of VTA dopamine neurons.
Experimental and numerical evaluation of the force due to the impact of a dam-break wave on a structure
Contributors: Francesca Aureli, Susanna Dazzi, Andrea Maranzoni, Paolo Mignosa, Renato Vacondio
... Flood events caused by the collapse of dams or river levees can have damaging consequences on buildings and infrastructure located in prone areas. Accordingly, a careful prediction of the hydrodynamic load acting on structures is important for flood hazard assessment and potential damage evaluation. However, this represents a challenging task and requires the use of suitable mathematical models. This paper investigates the capability of three different models, i.e. a 2D depth-averaged model, a 3D Eulerian two-phase model, and a 3D Smoothed Particle Hydrodynamics (SPH) model, to estimate the impact load exerted by a dam-break wave on an obstacle. To this purpose, idealised dam-break experiments were carried out by generating a flip-through impact against a rigid squat structure, and measurements of the impact force were obtained directly by using a load cell. The dynamics of the impact event was analyzed and related to the measured load time history. A repeatability analysis was performed due to the great variability typically shown by impact phenomena, and a confidence range was estimated. The comparison between numerical results and experimental data shows the capability of 3D models to reproduce the key features of the flip-through impact. The 2D modelling based on the shallow water approach is not entirely suitable to accurately reproduce the load hydrograph and predict the load peak values; this difficulty increases with the strength of the wave impact. Nevertheless, the error in the peak load estimation is in the order of 10% only, thus the 2D approach may be considered appropriate for practical applications. Moreover, when the shallow water approximation is expected to work well, 2D results are comparable with the experimental data, as well as with the numerical predictions of far more sophisticated and computationally demanding 3D solvers. All the numerical models overestimate the falling limb of the load hydrograph after the impact. The SPH model ensures good evaluation of the long-time load impulse. The 2D shallow water solver and the 3D Eulerian model are less accurate in predicting the load impulse but provide similar results. A sensitivity analysis with respect to the model parameters allows to assess model uncertainty. Finally, the experimental data collected have been made available online as supplementary material for validation purposes.
Contributors: Ramzan Ullah, Han Li, YiMing Zhu
... Time domain terahertz (0.2–2THz) and FTIR (400–4000cm−1) spectra of ‘Bisphenol A’ are presented. An average refractive index of 1.34 from 0.2 to 2THz and an absorption peak at 1.69THz that is considered as the twisting of aromatic rings with hydroxyl groups along the shared carbon atom are found. The simulated results by using density functional theory (DFT) with B3LYP 6-311++G (3df, 3pd), B3LYP 6-31G (3df 3pd) and B3LYP 3-21G after anharmonic corrections are well agreed with the experimental results. Furthermore, Pulay’s Method is adopted to overcome the incapability of DFT in describing C–H and O–H stretching interactions to match with experimental values.
Physical controls on mixing and transport within rising submarine hydrothermal plumes: A numerical simulation study
Contributors: Houshuo Jiang, John A. Breier
... A computational fluid dynamics (CFD) model was developed to simulate the turbulent flow and species transport of deep-sea high temperature hydrothermal plumes. The model solves numerically the density weighted unsteady Reynolds-averaged Navier–Stokes equations and energy equation and the species transport equation. Turbulent entrainment and mixing is modeled by a k–ε turbulence closure model. The CFD model explicitly considers realistic vent chimney geometry, vent exit fluid temperature and velocity, and background stratification. The model uses field measurements as model inputs and has been validated by field data. These measurements and data, including vent temperature and plume physical structure, were made in the ABE hydrothermal field of the Eastern Lau Spreading Center. A parametric sensitivity study based on this CFD model was conducted to determine the relative importance of vent exit velocity, background stratification, and chimney height on the mixing of vent fluid and seawater. The CFD model was also used to derive several important scalings that are relevant to understanding plume impact on the ocean. These scalings include maximum plume rise height, neutrally buoyant plume height, maximum plume induced turbulent diffusivity, and total plume vertically transported water mass flux. These scaling relationships can be used for constructing simplified 1-dimensional models of geochemistry and microbial activity in hydrothermal plumes. Simulation results show that the classical entrainment assumptions, typically invoked to describe hydrothermal plume transport, only apply up to the vertical level of ~0.6 times the maximum plume rise height. Below that level, the entrainment coefficient remains relatively constant (~0.15). Above that level, the plume flow consists of a pronounced lateral spreading flow, two branches of inward flow immediately above and below the lateral spreading, and recirculation flanking the plume cap region. Both turbulent kinetic energy and turbulence dissipation rate reach their maximum near the vent; however, turbulent viscosity attains its maximum near the plume top, indicating strong turbulent mixing in that region. The parametric study shows that near vent physical conditions, including chimney height and fluid exit velocity, influence plume mixing from the vent orifice to a distance of ~10 times the vent orifice diameter. Thus, physical parameters place a strong kinetic constraint on the chemical reactions occurring in the initial particle-forming zone of hydrothermal plumes.
Contributors: Leen Alawieh, Timothy P. Weihs, Omar M. Knio
... A multiscale inference analysis is conducted in order to infer intermixing rates prevailing during different reaction regimes in Ni/Al nanolaminates. The analysis combines the results of molecular dynamics (MD) simulations, used in conjunction with a mixing measure theory to characterize intermixing rates under adiabatic conditions. When incorporated into reduced reaction models, however, information extracted from MD computations leads to front propagation velocities that conflict with experimental observations, and the discrepancies indicate that our MD simulations over-estimate the atomic intermixing rates. Thus, using only insights gained from MD computations, a generalized diffusivity law is developed that exhibits a sharp rise near the melting temperature of Al. By calibrating the intermixing rates at high temperatures from experimental observations of self-propagating fronts, and inferring the intermixing rates at low and intermediate temperatures from ignition and nanocalorimetry experiments, the dependence of the diffusivity on temperature is inferred in a suitably wide temperature range. Using this generalized diffusivity law, one obtains a generalized reduced model that, for the first time, enables us to reproduce measurements of low-temperature ignition, homogeneous reactions at intermediate temperatures, as well as the dependence of the velocity of self-propagating reaction fronts on microstructural parameters.
Signal complexity and modular organization of the courtship behaviours of two sibling species of wolf spiders (Araneae: Lycosidae)
Contributors: Alberto Chiarle, Marco Isaia
... In this study, we compare the courtship behaviours of Pardosa proxima and P. vlijmi, two species of wolf spiders up to now regarded as “ethospecies”, by means of motion analysis methodologies. In particular, we investigate the features of the signals, aiming at understanding the evolution of the courtship and its role in species delimitation and speciation processes. In our model, we highlight a modular structure of the behaviours and the presence of recurring units and phases. According to other similar cases concerning animal communication, we observed one highly variable and one stereotyped phase for both species. The stereotyped phase is here regarded as a signal related to species identity or an honest signal linked directly to the quality of the signaler. On the contrary, the variable phase aims to facilitate signal detection and assessment by the female reducing choice costs or errors. Variable phases include cues arisen from Fisherian runaway selection, female sensory exploitation and remaining of past selections.
Elucidating geochemical response of shallow heterogeneous aquifers to CO2 leakage using high-performance computing: Implications for monitoring of CO2 sequestration
Contributors: Alexis K. Navarre-Sitchler, Reed M. Maxwell, Erica R. Siirila, Glenn E. Hammond, Peter C. Lichtner
... Predicting and quantifying impacts of potential carbon dioxide (CO2) leakage into shallow aquifers that overlie geologic CO2 storage formations is an important part of developing reliable carbon storage techniques. Leakage of CO2 through fractures, faults or faulty wellbores can reduce groundwater pH, inducing geochemical reactions that release solutes into the groundwater and pose a risk of degrading groundwater quality. In order to help quantify this risk, predictions of metal concentrations are needed during geologic storage of CO2. Here, we present regional-scale reactive transport simulations, at relatively fine-scale, of CO2 leakage into shallow aquifers run on the PFLOTRAN platform using high-performance computing. Multiple realizations of heterogeneous permeability distributions were generated using standard geostatistical methods. Increased statistical anisotropy of the permeability field resulted in more lateral and vertical spreading of the plume of impacted water, leading to increased Pb2+ (lead) concentrations and lower pH at a well down gradient of the CO2 leak. Pb2+ concentrations were higher in simulations where calcite was the source of Pb2+ compared to galena. The low solubility of galena effectively buffered the Pb2+ concentrations as galena reached saturation under reducing conditions along the flow path. In all cases, Pb2+ concentrations remained below the maximum contaminant level set by the EPA. Results from this study, compared to natural variability observed in aquifers, suggest that bicarbonate (HCO3−) concentrations may be a better geochemical indicator of a CO2 leak under the conditions simulated here.
Research papers - Horizontal Lagrangian transport in a tidal-driven estuary—Transport barriers attached to prominent coastal boundaries
Contributors: Florian Huhn, Alexandra von Kameke, Silvia Allen-Perkins, Pedro Montero, Anabela Venancio, Vicente Pérez-Muñuzuri
... Horizontal Lagrangian surface transport is studied in the Ria de Vigo, an estuary in NW Spain with tidal and wind-driven dynamics. Surface drifters and the surface flow from a high-resolution 3-D hydrodynamic model are compared to each other. In particular, our analysis is based on a classical comparison of real and artificial trajectories and on Lagrangian Coherent Structures (LCS) defined as ridges in spatial fields of the Finite-Time Lyapunov Exponent (FTLE). The trajectories of the drifters are in good agreement with the prediction of the model in two out of four cases. Further, FTLE ridges computed from the model velocity fields are found to mark transport barriers for the drifters. The results indicate that the model is able to represent the general circulation in the estuary. Main patterns in the Lagrangian surface transport in the model are shown for two typical meteorological situations, north wind and south wind. They can be interpreted as an imprint of a 3-dimensional circulation pattern in the Ria de Vigo and reveal in detail the separation of the time-dependent in- and outflow at the surface of the estuary.
Contributors: Timothy L. Turner, Victoria H. Nguyen, Craig C. McLauchlan, Zaneta Dymon, Benjamin M. Dorsey, Jaqueline D. Hooker, Marjorie A. Jones
... Multiple studies report apparent effects of vanadium on various systems in vivo and in vitro. Vanadium species may be possible deterrents for the growth of the Leishmania parasite, which causes the sometimes deadly diseases known as leishmaniasis. The current studies focus specifically on decavanadate V10O286- (V10), which has a potential to be a potent effector for disease treatment. The X-ray structure of a new solvate salt of V10, namely (NH4)6V10O28·5H2O, is also reported. Other vanadium complexes with imidazole carboxylate, anthranilate, or picolinate were also evaluated. The yellow-orange oxoanion, used as the (NH4)6V10O28·6H2O salt, was tested (at 1–100μM) directly with two strains of Leishmania tarentolae promastigotes in culture to evaluate the effect on cell viability. Vanadium coordination complexes are known effective inhibitors of phosphatases. Using the artificial phosphatase substrate para-nitrophenylphosphate in the presence of a bovine calf intestine alkaline phosphatase enzyme, V10 (from 5 to 100μM) was shown to be a mixed inhibitor for this enzyme and decreased the activity of the other two phosphatases tested. The effect of V10 and the other vanadium complexes on the activity of phosphoglycerate mutase B (PGAM), an important enzyme in glycolysis and gluconeogenesis, was also evaluated. At 10μM, V10 was the most potent inhibitor of PGAM, with an apparent reduction of about 50%. Taken together, we speculate that V10 could have a role in treating Leishmania diseases.