Field-effect transitor differential amplifier

The feasibility of using field-effect transistors in wide-band differential amplifier applications has been investigated. An analysis of bipolar transistor differential amplifiers is included which demonstrates the problem of thermal drift and low input impedance present in all low level transistor amplifiers. An investigation of a field-effect transistor shows that such a device possesses the properties of zero thermal drift at a particular bias point, extremely high input impedance, good radiation resistance, low noise, and a high power gain. It is therefore postulated that employing FET\u27s in a differential amplifier will result in a circuit having very high input impedance and low thermal drift

Predicting Students\u27 Spiritual and Religious Competence Based on Supervisor Practices and Institutional Attendance

Counseling students report a lack of competence in spiritual and religious integration (SRI). As such, counselor educators and supervisors (CES) and students want to understand how to develop SRI competence. Although past research highlights SRI dialogue in training, there exists no clear understanding about the role of faculty supervisor SRI on perceived student competence. The supervision models used to inform the study included (a) the integrated developmental model, (b) the discrimination model, and (c) the spirituality in supervision model (SACRED). The purpose of this study is to determine if master’s-level graduate counseling student perceptions of faculty supervisor SRI practices predicts student perceived spiritual competence when considering attendance in faith-based and non-faith-based institutions accredited by the Council for Accreditation of Counseling and Related Education Programs (CACREP). A review of existing literature supports the use of a quantitative, cross-sectional design. An online survey was distributed to students (n = 59) in master’s-level CACREP counseling programs, currently in field experience, to measure perceived SRI in supervision and perceived SRI competence. A multiple linear regression reveals a statistically significant predictive relationship between supervisor SRI and perceived student competence as measured by the Spiritual and Religious Competence Assessment and the Spiritual Issues in Supervision Scale. These results inform CES about the importance of SRI and student ability to work with the spiritual and religious beliefs of clients. On this basis, it is recommended that supervisors focus on SRI in supervision. Future research should focus on additional factors related to SRI competence during counselor training

A Review of Agent Emotion Architectures

This paper attempts to highlight some of the research that has been conducted worldwide in the area of computational models of emotions, with a particular emphasis on agent emotions suitable for simulations and games. The intended outcome is to both review some of the more prominent research in the field, and to also ascertain the level of formal psychology that may underpin such work with a view to proposing that there is scope for an architecture built from the ground up, that arises from non-conflicting theories of emotion

Micron-Scale Plasma Membrane Curvature is Recognized by the Septin Cytoskeleton

Cells change shape in response to diverse environmental and developmental conditions, creating topologies with micron-scale features. Although individual proteins can sense nanometer-scale membrane curvature, it is unclear if a cell could also use nanometer-scale components to sense micron-scale contours, such as the cytokinetic furrow and base of neuronal branches. Septins are filament-forming proteins that serve as signaling platforms and are frequently associated with areas of the plasma membrane where there is micron-scale curvature, including the cytokinetic furrow and the base of cell protrusions. We report here that fungal and human septins are able to distinguish between different degrees of micron-scale curvature in cells. By preparing supported lipid bilayers on beads of different curvature, we reconstitute and measure the intrinsic septin curvature preference. We conclude that micron-scale curvature recognition is a fundamental property of the septin cytoskeleton that provides the cell with a mechanism to know its local shape

Septin assemblies form by diffusion-driven annealing on membranes

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 111 (2014): 2146-2151, doi:10.1073/pnas.1314138111.Septins assemble into filaments and higher-order structures that act as scaffolds for diverse cell functions including cytokinesis, cell polarity, and membrane remodeling. Despite their conserved role in cell organization, little is known about how septin filaments elongate and are knit together into higher-order assemblies. Using fluorescence correlation spectroscopy (FCS), we determined that cytosolic septins are in small complexes suggesting that septin filaments are not formed in the cytosol. When the plasma membrane of live cells is monitored by total internal reflection fluorescence (TIRF) microscopy, we see that septin complexes of variable size diffuse in two dimensions. Diffusing septin complexes collide and make end-on associations to form elongated filaments and higher-order structures, an assembly process we call annealing. Septin assembly by annealing can be reconstituted in vitro on supported lipid bilayers with purified septin complexes. Using the reconstitution assay, we show that septin filaments are highly flexible, grow only from free filament ends and do not exchange subunits in the middle of filaments. This work shows for the first time that annealing is an intrinsic property of septins in the presence of membranes and demonstrates that cells exploit this mechanism to build large septin assemblies.This project was supported with funding from by NSF (MCB-507511, ASG) and NIH (GM100160, TT and ASG), and Colwin, Lemann and Spiegel summer fellowships and The Nikon Award for summer investigation at MBL in Woods Hole, MA (ASG) and instrument support from Micro Video Instruments (MVI).2014-07-2

Landscape-Scale Land-Cover Change and Long-Term Abundance of Scaled Quail and Northern Bobwhite in Texas

Between 1978 and 1998, scaled quail (Callipepla squamata) abundance in the Rolling Plains ecological region declined (r1 = -0.85, P \u3c 0.001), while no trend (P = 0.74) was exhibited in the South Texas Plains. Northern bobwhites (Colinus virginianus) exhibited no trend (P \u3e 0.10) in either ecological region. Changes in land-cover between 1976 and 1998 indicated a loss of Savannah and Shrubland and an increase in Parkland cover types in the Rolling Plains. In the South Texas Plains, Woodland and Brush/Shrubland decreased between 1976 and 1998, whereas Brush/Shrub Parkland and Parkland increased. We examined land-cover change as a possible component in the scaled quail decline in the Rolling Plains. Loss of the Shrubland cover type may explain the decline of scaled quail in the Rolling Plains. Our results further suggest intraspecific spatial usability boundaries. These boundaries differed by species, with scaled quail associated with dense structure near the ground, whereas northern bobwhite were less abundant in areas dominated by scattered shrubs and trees, and large expanses of short, close-canopy cover types. A method is proposed for quickly obtaining data on land-cover changes on time

Reduced Acute Inflammatory Responses to Microgel Conformal Coatings

Implantation of synthetic materials into the body elicits inflammatory host responses that limit medical device integration and biological performance. This inflammatory cascade involves protein adsorption, leukocyte recruitment and activation, cytokine release, and fibrous encapsulation of the implant. We present a coating strategy based on thin films of poly(N-isopropylacrylamide) hydrogel microparticles (i.e. microgels) cross-linked with poly(ethylene glycol) diacrylate. These particles were grafted onto a clinically relevant polymeric material to generate conformal coatings that significantly reduced in vitro fibrinogen adsorption and primary human monocyte/macrophage adhesion and spreading. These microgel coatings also reduced leukocyte adhesion and expression of pro-inflammatory cytokines (TNF-alpha, IL-1 beta, MCP-1) in response to materials implanted acutely in the murine intraperitoneal space. These microgel coatings can be applied to biomedical implants as a protective coating to attenuate biofouling, leukocyte adhesion and activation, and adverse host responses for biomedical and biotechnological applications

Spectroscopy of Globular Clusters in M81

We present moderate-resolution spectroscopy of globular clusters (GCs) around the Sa/Sb spiral galaxy M81 (NGC 3031). Sixteen candidate clusters were observed with the Low Resolution Imaging Spectrograph on the Keck I telescope. All are confirmed as bona fide GCs, although one of the clusters appears to have been undergoing a transient event during our observations. In general, the M81 globular cluster system (GCS) is found to be very similar to the Milky Way (MW) and M31 systems, both chemically and kinematically. A kinematic analysis of the velocities of 44 M81 GCS, (the 16 presented here and 28 from previous work) strongly suggests that the red, metal-rich clusters are rotating in the same sense as the gas in the disk of M81. The blue, metal-poor clusters have halo-like kinematics, showing no evidence for rotation. The kinematics of clusters whose projected galactocentric radii lie between 4 and 8 kpc suggest that they are rotating much more than those which lie outside these bounds. We suggest that these rotating, intermediate-distance clusters are analogous to the kinematic sub-population in the metal-rich, disk GCs observed in the MW and we present evidence for the existence of a similar sub-population in the metal-rich clusters of M31. With one exception, all of the M81 clusters in our sample have ages that are consistent with MW and M31 GCs. One cluster may be as young as a few Gyrs. The correlations between absorption-line indices established for MW and M31 GCs also hold in the M81 cluster system, at least at the upper end of the metallicity distribution (which our sample probes). On the whole, the mean metallicity of the M81 GCS is similar to the metallicity of the MW and M31 GCSs. The projected mass of M81 is similar to the masses of the MW and M31. Its mass profile indicates the presence of a dark matter halo.Comment: 35 pages, including 11 figures and 9 tables. Accepted for publication in the Astronomical Journa