Light Phase Testing of Social Behaviors: Not a Problem

The rich repertoire of mouse social behaviors makes it possible to use mouse models to study neurodevelopmental disorders characterized by social deficits. The fact that mice are naturally nocturnal animals raises a critical question of whether behavioral experiments should be strictly conducted in the dark phase and whether light phase testing is a major methodologically mistake. Although mouse social tasks have been performed in both phases in different laboratories, there seems to be no general consensus on whether testing phase is a critical factor or not. A recent study from our group showed remarkably similar social scores obtained from inbred mice tested in the light and the dark phase, providing evidence that light phase testing could yield reliable results as robust as dark phase testing for the sociability test. Here we offer a comprehensive review on mouse social behaviors measured in light and dark phases and explain why it is reasonable to test laboratory mice in experimental social tasks in the light phase

Environmental factors influence both abundance and genetic diversity in a widespread bird species.

Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors may drive patterns of genetic diversity. However, the relationship between the genetic diversity of a population and how this interacts with ecological processes has so far only been investigated in a few studies. Here, we investigate the link between ecological factors, local population size, and allelic diversity, using a field study of a common bird species, the house sparrow (Passer domesticus). We studied sparrows outside the breeding season in a confined small valley dominated by dispersed farms and small-scale agriculture in southern France. Population surveys at 36 locations revealed that sparrows were more abundant in locations with high food availability. We then captured and genotyped 891 house sparrows at 10 microsatellite loci from a subset of these locations (N = 12). Population genetic analyses revealed weak genetic structure, where each locality represented a distinct substructure within the study area. We found that food availability was the main factor among others tested to influence the genetic structure between locations. These results suggest that ecological factors can have strong impacts on both population size per se and intrapopulation genetic variation even at a small scale. On a more general level, our data indicate that a patchy environment and low dispersal rate can result in fine-scale patterns of genetic diversity. Given the importance of genetic diversity for population viability, combining ecological and genetic data can help to identify factors limiting population size and determine the conservation potential of populations

Study of Giant Pairing Vibrations with neutron-rich nuclei

We investigate the possible signature of the presence of giant pairing states at excitation energy of about 10 MeV via two-particle transfer reactions induced by neutron-rich weakly-bound projectiles. Performing particle-particle RPA calculations on $^{208}$Pb and BCS+RPA calculations on $^{116}$Sn, we obtain the pairing strength distribution for two particles addition and removal modes. Estimates of two-particle transfer cross sections can be obtained in the framework of the 'macroscopic model'. The weak-binding nature of the projectile kinematically favours transitions to high-lying states. In the case of (~^6He, \~^4He) reaction we predict a population of the Giant Pairing Vibration with cross sections of the order of a millibarn, dominating over the mismatched transition to the ground state.Comment: Talk presented in occasion of the VII School-Semina r on Heavy Ion Physics hosted by the Flerov Laboratory (FLNR/JINR) Dubna, Russia from May 27 to June 2, 200

Adaptive latitudinal variation in Common Blackbird Turdus merula nest characteristics

Nest construction is taxonomically widespread, yet our understanding of adaptive intraspecific variation in nest design remains poor. Nest characteristics are expected to vary adaptively in response to predictable variation in spring temperatures over large spatial scales, yet such variation in nest design remains largely overlooked, particularly amongst open-cup-nesting birds. Here, we systematically examined the effects of latitudinal variation in spring temperatures and precipitation on the morphology, volume, composition, and insulatory properties of open-cup-nesting Common Blackbirds’ Turdus merula nests to test the hypothesis that birds living in cooler environments at more northerly latitudes would build better insulated nests than conspecifics living in warmer environments at more southerly latitudes. As spring temperatures increased with decreasing latitude, the external diameter of nests decreased. However, as nest wall thickness also decreased, there was no variation in the diameter of the internal nest cups. Only the mass of dry grasses within nests decreased with warmer temperatures at lower latitudes. The insulatory properties of nests declined with warmer temperatures at lower latitudes and nests containing greater amounts of dry grasses had higher insulatory properties. The insulatory properties of nests decreased with warmer temperatures at lower latitudes, via changes in morphology (wall thickness) and composition (dry grasses). Meanwhile, spring precipitation did not vary with latitude, and none of the nest characteristics varied with spring precipitation. This suggests that Common Blackbirds nesting at higher latitudes were building nests with thicker walls in order to counteract the cooler temperatures. We have provided evidence that the nest construction behavior of open-cup-nesting birds systematically varies in response to large-scale spatial variation in spring temperatures

Light particle spectra from 35 MeV/nucleon 12C-induced reactions on 197Au

Energy spectra for p, d, t, 3He, 4He, and 6He from the reaction 12C+197Au at 35 MeV/nucleon are presented. A common intermediate rapidity source is identified using a moving source fit to the spectra that yields cross sections which are compared to analogous data at other bombarding energies and to several different models. The excitation function of the composite to proton ratios is compared with quantum statistical, hydrodynamic, and thermal models

The six-sphere framework: A practical tool for assessing monitoring and evaluation systems

Background: Successful evaluation capacity development (ECD) at regional, national and institutional levels has been built on a sound understanding of the opportunities and constraints in establishing and sustaining a monitoring and evaluation system. Diagnostics are one of the tools that ECD agents can use to better understand the nature of the ECD environment. Conventional diagnostics have typically focused on issues related to technical capacity and the ‘bridging of the gap’ between evaluation supply and demand. In so doing, they risk overlooking the more subtle organisational and environmental factors that lie outside the conventional diagnostic lens. Method: As a result of programming and dialogue carried out by the Centre for Learning on Evaluation and Results Anglophone Africa engaging with government planners, evaluators, civil society groups and voluntary organisations, the author has developed a modified diagnostic tool that extends the scope of conventional analysis. Results: This article outlines the six-sphere framework that can be used to extend the scope of such diagnostics to include considerations of the political environment, trust and collaboration between key stakeholders and the principles and values that underpin the whole system. The framework employs a graphic device that allows the capture and organisation of structural knowledge relating to the ECD environment. Conclusion: The article describes the framework in relation to other organisational development tools and gives some examples of how it can be used to make sense of the ECD environment. It highlights the potential of the framework to contribute to a more nuanced understanding of the ECD environment using a structured diagnostic approach and to move beyond conventional supply and demand models

Electrochemical Determination of the Heterogeneous Electron Transfer Kinetics of Soluble Spinach Ferredoxin

The application of electrochemical techniques to biological systems has become an attractive method for characterizing the redox and electron transfer behavior of biomacromolecules. This study focuses on the role of soluble spinach ferredoxin (Fd) in photosynthesis where it functions as an electron carrier to membrane bound species in the plant chloroplast. An electrochemical model is used where in Fd now serves as a soluble redox species which undergoes oxidation and reduction via electron transfer at an electrode. This type of model is significant in that both the membrane and electrode reactive sites are characterized by charged bilayer interfacial regions which significantly influence electron transfer rates. The formal heterogeneous electron transfer rate constant, kf0:h\u27 and the eletrochemical transfer coefficient, a, were determined using transient and steady state electrochemical techniques. Transient oxidative and reductive kinetic data were obtained spectroelectrochemically via single potential step chronoabsorptometry (SPSC) at three different surfaces: methyl viologen modified gold (MVMG) minigrid electrodes, tin oxide (Sn02) semiconductor electrodes and at metallized plastic gold optically transparent electrodes (MPOTE). The steady state measurements were made via hydrodynamic voltammetry at a MVMG rotating ring - disk electrode (RRDE). Only the modified gold surfaces resulted in behavior suitable for the determination of heterogeneous electron transfer kinetic parameters. The transient kinetics of Fd were initially evaluated using an irreversible Butler-Volmer kinetic model descriptive of species exhibiting slow rates of electron transfer at an electrode surface. This yielded an average kf0;h = 6.5 (± 1.3) x 10- 5cm/sec and a = 0.60 (±0.16) for reductive experiments performed at four different modified gold surfaces . Recently the theory for SPSC was extended to quasi-reversible systems, which undergo moderate rates of electron transfer. Since Fd exhibits quasi-reversible behavior at the MVMG grid, the transient reductive data were reanalyzed using this more exact model. The values obtained using the quasi-reversible model were kf,0’h= 1.16 (±0.5) x 10-4 cm/sec and α = 0.42 ( ±0.06 ). The corresponding reductive steady state results at the modified RRDE yielded kf,0’h = 5.9 ( ±0.05 ) x 10-4 cm/sec and α=0.476 (± 0.001). Oxidative experiments were only successful with transient experiments at the MVMG minigrid surface where in kf,0’h =3.39 (± 0.01) x 1 0- 5 cm/sec and α = 1.17 (0.02). Absorbance data also indicates protein adsorption as a prestep to electron transfer. This type of phenomenon is common to biological molecules reacting at electrodes. The behavior of Fd at these surfaces and the kinetic results are discussed in terms of mechanistic implications.The formal heterogeneous electron transfer rate constant, kf0h and the eletrochemical transfer coefficient, a, were determined using transient and steady state electrochemical techniques. Transient oxidative and reductive kinetic data were obtained spectroelectrochemically via single potential step chronoabsorptometry (SPSC) at three different surfaces: methyl viologen modified gold (MVMG) minigrid electrodes, tin oxide (Sn02) semiconductor electrodes and at metallized plastic gold optically transparent electrodes (MPOTE). The steady state measurements were made via hydrodynamic voltammetry at a MVMG rotating ring - disk electrode (RRDE). Only the modified gold surfaces resulted in behavior suitable for the determination of heterogeneous electron transfer kinetic parameters. The transient kinetics of Fd were initially evaluated using an irreversible Butler-Volmer kinetic model descriptive of species exhibiting slow rates of electron transfer at an electrode surface. This yielded an average kf0h = 6.5 (± 1.3) x 10- 5cm/sec and a = 0 . 60 (±0.16) for reductive experiments performed at four different modified gold surfaces . Recently the theory for SPSC was extended to quasi-reversible systems, which undergo moderate rates of electron transfer. Since Fd exhibits quasi-reversible behavior at the MVMG grid, the transient reductive data were reanalyzed using this more exact model. The values obtained using the quasi-reversible model were kf0h= 1.16 (±0 . 5) x 10-4 cm/sec and α = 0.42 ( ±0.06 ). The corresponding reductive steady state results at the modified RRDE yielded kf0h = 5.9 ( ±0.05 ) x 10-4 cm/sec and α=0.476 (± 0.001). Oxidative experiments were only successful with transient experiments at the MVMG minigrid surface where in kf0h =3.39 (± 0.01) x 1 0- 5 cm/sec and α = 1.17 (0.02). Absorbance data also indicates protein adsorption as a prestep to electron transfer. This type of phenomenon is common to biological molecules reacting at electrodes. The behavior of Fd at these surfaces and the kinetic results are discussed in terms of mechanistic implications

Optimum operating policies for multiple reservoir systems

Thesis (M.Eng.Sci.) -- University of Adelaide, Dept. of Civil Engineering, 199