Intrinsic Cornu Ammonis Area 1 Theta-Nested Gamma Oscillations Induced by Optogenetic Theta Frequency Stimulation.

UNLABELLED: Gamma oscillations (30-120 Hz) are thought to be important for various cognitive functions, including perception and working memory, and disruption of these oscillations has been implicated in brain disorders, such as schizophrenia and Alzheimer's disease. The cornu ammonis area 1 (CA1) of the hippocampus receives gamma frequency inputs from upstream regions (cornu ammonis area 3 and medial entorhinal cortex) and generates itself a faster gamma oscillation. The exact nature and origin of the intrinsic CA1 gamma oscillation is still under debate. Here, we expressed channel rhodopsin-2 under the CaMKIIα promoter in mice and prepared hippocampal slices to produce a model of intrinsic CA1 gamma oscillations. Sinusoidal optical stimulation of CA1 at theta frequency was found to induce robust theta-nested gamma oscillations with a temporal and spatial profile similar to CA1 gamma in vivo The results suggest the presence of a single gamma rhythm generator with a frequency range of 65-75 Hz at 32 °C. Pharmacological analysis found that the oscillations depended on both AMPA and GABAA receptors. Cell-attached and whole-cell recordings revealed that excitatory neuron firing slightly preceded interneuron firing within each gamma cycle, suggesting that this intrinsic CA1 gamma oscillation is generated with a pyramidal-interneuron circuit mechanism. SIGNIFICANCE STATEMENT: This study demonstrates that the cornu ammonis area 1 (CA1) is capable of generating intrinsic gamma oscillations in response to theta input. This gamma generator is independent of activity in the upstream regions, highlighting that CA1 can produce its own gamma oscillation in addition to inheriting activity from the upstream regions. This supports the theory that gamma oscillations predominantly function to achieve local synchrony, and that a local gamma generated in each area conducts the signal to the downstream region.J.L.B. is support by a Biotechnology and Biological Sciences Research Council CASE Studentship in collaboration with Eli Lilly and Company, and P.R.F.M. is supported by a CAPES Science without Borders Cambridge Scholarship.This is the final version of the article. It first appeared from the Society for Neuroscience via http://dx.doi.org/10.1523/JNEUROSCI.3150-15.201

Exploring shear alignment of concentrated wormlike micelles using rheology coupled with small-angle neutron scattering

Wormlike micelles (WLMs) are vital components of many consumer products and industrial fluids, adding a shear-dependent viscous texture through their entanglement in solutions. It is now well accepted from experiments such as coupling rheology and scattering that, similar to many polymer solutions and dispersions of highly anisotropic particles, WLM behavior during shear arises from the alignment of the "worms"with the shear field, resulting in ordering that is rapidly lost in the cessation of shear. Most studies of such systems have been limited to dilute systems that are far below concentrations used industrially and commercially, due to the complexity of analyzing shear-induced many-body effects in high volume fraction dispersions. Here, we explore the shear alignment of concentrated WLM solutions comprising sodium laureth sulfate and cocamidopropyl betaine in 0.38 M aqueous sodium chloride. By analyzing only scattering data at high values of the scattering vector (i.e., correlations at short length scales that are dominant in such concentrated systems), we explore whether useful information can be obtained by naïvely approximating the WLMs as an ensemble of unconnected short rods representing sections of the worms. By taking this reductionist approach to analyzing the obtained two-dimensional scattering patterns from these systems under shear, we find that in this regime, such concentrated worms can be approximated as cylinders that become more aligned with the direction of shear as volume fraction and shear rate increase

Functional Diffuse Optical Spectroscopy of Human Breast Tissue

A method was described for using steady-state and frequency-domain reflectance measurements to obtain broad wavelength quantitative data with deep tissue penetration. Fundamental information on tissue biochemistry and structure was provided using the wavelength-dependence of absorption and scattering parameters. Results showed that total hemoglobin content, water and lipid percentage can be measured using this technique

How Valid Are Measures of Children’s Self-Concept/ Self-Esteem? Factors and Content Validity in Three Widely Used Scales

Children’s self-esteem/self-concept, a core psychological construct, has been measured in an overwhelming number of studies, and the widespread use of such measures should indicate they have well-established content validity, internal consistency and factor structures. This study, sampling a demographically representative cohort in late childhood/early adolescence in Dublin, Ireland (total n = 651), examined three major self-esteem/self-concept scales designed for late childhood/early adolescence: Piers-Harris Self-Concept Scale for Children 2 (Piers et al. 2002), Self-Description Questionnaire I (Marsh 1992) and Self-Perception Profile for Children (Harter 1985). It also examined findings in light of the salient self factors identified by participants in a linked mixed-methods study. The factor structure of Piers-Harris Self-Concept Scale was not replicated. The Self-Description Questionnaire I and Self-Perception Profile for Children were replicated only in part although in similar ways. In all three scales, a global/ appearance self evaluation factor accounted for the largest variance in factor analyses. Sport/athletic ability, school ability, school enjoyment, maths and reading ability/enjoyment, behaviour, peer popularity, and parent factors were also identified but did not always reflect existing scale structures. Notably, the factors extracted, or items present in these scales, often did not reflect young people’s priorities, such as friendship over popularity, the importance of family and extended family members, and the significance of incremental personal mastery in activities rather than assessing oneself as comparatively good at preferred activities. The findings raise questions about how self-esteem/self-concept scales are used and interpreted in research with children and young people

Biophysical connectivity explains population genetic structure in a highly dispersive marine species

© 2016 Springer-Verlag Berlin Heidelberg Connectivity, the exchange of individuals among locations, is a fundamental ecological process that explains how otherwise disparate populations interact. For most marine organisms, dispersal occurs primarily during a pelagic larval phase that connects populations. We paired population structure from comprehensive genetic sampling and biophysical larval transport modeling to describe how spiny lobster (Panulirus argus) population differentiation is related to biological oceanography. A total of 581 lobsters were genotyped with 11 microsatellites from ten locations around the greater Caribbean. The overall FST of 0.0016 (P = 0.005) suggested low yet significant levels of structuring among sites. An isolation by geographic distance model did not explain spatial patterns of genetic differentiation in P. argus (P = 0.19; Mantel r = 0.18), whereas a biophysical connectivity model provided a significant explanation of population differentiation (P = 0.04; Mantel r = 0.47). Thus, even for a widely dispersing species, dispersal occurs over a continuum where basin-wide larval retention creates genetic structure. Our study provides a framework for future explorations of wide-scale larval dispersal and marine connectivity by integrating empirical genetic research and probabilistic modeling

Environmental Conditions Influence Allometric Patterns in the Blow Fly, Chrysomya albiceps

The objective of this research was to study variations in allometry of body characters in females and males of two populations of blow flies, Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae), under different environmental conditions to establish patterns of morphological variation. Body size of both males and females in the experimental population was significantly higher than in the individuals of the natural population, indicating an important influence of food on body size. All genitalic and non-genitalic characters in males and females of the two populations showed a trend towards negative allometry rather than isometry. Allometric patterns were modified in both sexes and between populations. The data show generally larger allometric slopes in females than in males. We confirmed that the environmental conditions have an important effect on allometric patterns and body size

The psychological-type profile of lay church leaders in Australia

A sample of 845 lay church leaders (444 women and 401 men) from a range of 24 different denominations and movements (including house churches and independent churches) completed the Francis Psychological-Type Scales within the context of the 2006 Australian National Church Life Survey. The psychological-type profiles of these lay church leaders were almost identical to the type profiles of 1527 Australian churchgoers (936 women and 591 men) published in an earlier study by Robbins and Francis. The predominant types among female lay church leaders were ISFJ (21%), ESFJ (21%), and ISTJ (18%). The predominant types among male lay church leaders were ISTJ (28%), ISFJ (17%), ESTJ (13%), and ESFJ (12%). The SJ temperament accounted for 67% of the female lay church leaders and for 70% of the male lay church leaders. The strengths and weaknesses of the SJ leadership style are discussed

Constraints on the Progenitor System of the Type Ia Supernova SN 2011fe/PTF11kly

Type Ia supernovae (SNe) serve as a fundamental pillar of modern cosmology, owing to their large luminosity and a well-defined relationship between light-curve shape and peak brightness. The precision distance measurements enabled by SNe Ia first revealed the accelerating expansion of the universe, now widely believed (though hardly understood) to require the presence of a mysterious "dark" energy. General consensus holds that Type Ia SNe result from thermonuclear explosions of a white dwarf (WD) in a binary system; however, little is known of the precise nature of the companion star and the physical properties of the progenitor system. Here we make use of extensive historical imaging obtained at the location of SN 2011fe/PTF11kly, the closest SN Ia discovered in the digital imaging era, to constrain the visible-light luminosity of the progenitor to be 10-100 times fainter than previous limits on other SN Ia progenitors. This directly rules out luminous red giants and the vast majority of helium stars as the mass-donating companion to the exploding white dwarf. Any evolved red companion must have been born with mass less than 3.5 times the mass of the Sun. These observations favour a scenario where the exploding WD of SN 2011fe/PTF11kly, accreted matter either from another WD, or by Roche-lobe overflow from a subgiant or main-sequence companion star.Comment: 22 pages, 6 figures, submitte

Nucleotide Discrimination with DNA Immobilized in the MspA Nanopore

Nanopore sequencing has the potential to become a fast and low-cost DNA sequencing platform. An ionic current passing through a small pore would directly map the sequence of single stranded DNA (ssDNA) driven through the constriction. The pore protein, MspA, derived from Mycobacterium smegmatis, has a short and narrow channel constriction ideally suited for nanopore sequencing. To study MspA's ability to resolve nucleotides, we held ssDNA within the pore using a biotin-NeutrAvidin complex. We show that homopolymers of adenine, cytosine, thymine, and guanine in MspA exhibit much larger current differences than in α-hemolysin. Additionally, methylated cytosine is distinguishable from unmethylated cytosine. We establish that single nucleotide substitutions within homopolymer ssDNA can be detected when held in MspA's constriction. Using genomic single nucleotide polymorphisms, we demonstrate that single nucleotides within random DNA can be identified. Our results indicate that MspA has high signal-to-noise ratio and the single nucleotide sensitivity desired for nanopore sequencing devices