811 research outputs found
Calcium Homeostasis in Escherichia coli: Characterization of Mutants and Genome Expression of MG1655
While the role of calcium ions as secondary messengers has been well described in eukaryotic cells, little is known about calcium homeostasis in bacteria at the physiological and molecular levels. Genetic and genomic approaches were used to address calcium regulation and to identify genes (cal) involved in calcium homeostasis. Transposon mutagenesis of Escherichia coli generated several calcium-sensitive mutants that fell into three categories: (i) Ca2+-sensitive chemotaxis mutants, (ii) Ca2+-sensitive cell division mutants, and (iii) Ca2+-sensitive mutants that showed no defects in cell division or chemotaxis. The physiological properties of these Ca2+-sensitive mutants were determined. Besides calcium-sensitivity to 75 mM calcium, all of the mutants exhibited increased sensitivities to several divalent cations including Ni2+, Mg2+, Mn2+, Co2+, Zn2+, Cu2+, and Cd2+. To identify the cal gene sequence in the Ca2+-sensitive mutants, the region of the genes fused to the reporter gene (phoA) on the transposon TnphoA was amplified by PCR and sequenced. The sites of the gene fusion for three cal mutants were at the fdoG, gpt and pqi5 genes. The pleiotropic nature for the cal mutations suggested that many genes may be globally regulated by calcium. We then investigated global gene expression patterns of wild-type E. coli under calcium-depleted (addition of 10 mM EGTA) and calcium-elevated (addition of 75 mM Ca2+) conditions as compared to cultures grown under unstressed conditions. A comprehensive transcriptome analysis using macroarrys exhibited a global regulation of diverse genes within the E. coli genome during calcium homeostasis
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Six month durability of targeted cognitive training supplemented with social cognition exercises in schizophrenia.
Background:Deficits in cognition, social cognition, and motivation are significant predictors of poor functional outcomes in schizophrenia. Evidence of durable benefit following social cognitive training is limited. We previously reported the effects of 70 h of targeted cognitive training supplemented with social cognitive exercises (TCT + SCT) verses targeted cognitive training alone (TCT). Here, we report the effects six months after training. Methods:111 participants with schizophrenia spectrum disorders were randomly assigned to TCT + SCT or TCT-only. Six months after training, thirty-four subjects (18 TCT + SCT, 16 TCT-only) were assessed on cognition, social cognition, reward processing, symptoms, and functioning. Intent to treat analyses was used to test the durability of gains, and the association of gains with improvements in functioning and reward processing were tested. Results:Both groups showed durable improvements in multiple cognitive domains, symptoms, and functional capacity. Gains in global cognition were significantly associated with gains in functional capacity. In the TCT + SCT group, participants showed durable improvements in prosody identification and reward processing, relative to the TCT-only group. Gains in reward processing in the TCT + SCT group were significantly associated with improvements in social functioning. Conclusions:Both TCT + SCT and TCT-only result in durable improvements in cognition, symptoms, and functional capacity six months post-intervention. Supplementing TCT with social cognitive training offers greater and enduring benefits in prosody identification and reward processing. These results suggest that novel cognitive training approaches that integrate social cognitive exercises may lead to greater improvements in reward processing and functioning in individuals with schizophrenia
Current and Nascent SETI Instruments
Here we describe our ongoing efforts to develop high-performance and
sensitive instrumentation for use in the search for extra-terrestrial
intelligence (SETI). These efforts include our recently deployed Search for
Extraterrestrial Emissions from Nearby Developed Intelligent Populations
Spectrometer (SERENDIP V.v) and two instruments currently under development;
the Heterogeneous Radio SETI Spectrometer (HRSS) for SETI observations in the
radio spectrum and the Optical SETI Fast Photometer (OSFP) for SETI
observations in the optical band. We will discuss the basic SERENDIP V.v
instrument design and initial analysis methodology, along with instrument
architectures and observation strategies for OSFP and HRSS. In addition, we
will demonstrate how these instruments may be built using low-cost, modular
components and programmed and operated by students using common languages, e.g.
ANSI C.Comment: 12 pages, 5 figures, Original version appears as Chapter 2 in "The
Proceedings of SETI Sessions at the 2010 Astrobiology Science Conference:
Communication with Extraterrestrial Intelligence (CETI)," Douglas A. Vakoch,
Edito
Contaminant Analysis of Domestic Well Water in Norton and Phillips Counties, Kansas
The Alluvial aquifer in Kansas is responsible for supplying much of western Kansas with fresh domestic well water Samples from these domestic wells were collected from participating landowners along the Alluvial aquifer of Norton and Phillips counties, Kansas The collected samples were shipped to the Kansas Department of Health and Environment ( Laboratories for analysis of various regulated contaminants The following parameters were measured from each water sample uranium, nitrate, sulfate, iron, selenium, manganese, chloride, arsenic, and conductivity Using ArcGIS Pro, the locations of the sampled wells were converted into point data with their respective parameter data attached Several cartographic maps were constructed to represent the concentration of each contaminant along the length of the Alluvial aquifer Additional maps representing soil type, land use, and local geology were constructed to aid in the analysis of wells containing contaminants over the maximum contamination level ( The resulting collection of attribute data and maps were returned to the KDHE for future purposes This is an ongoing project with an aim to express the importance of consistent monitoring of contaminants in domestic wells This summer, we will continue analysis of the Alluvial aquifer traveling westward into the Kansas counties of Rawlins and Decatur We look forward to gathering more data to help us determine if land use and local geology could be a contributing source of contaminatio
The Process of Marriage Equality
This article offers the first comprehensive history of the marriageequality litigation process leading from Windsor to Obergefell. It explores how four aspects of federal procedure and jurisdiction doctrine both enabled and frustrated marriage equality\u27s advancement to the Supreme Court. First, we examine common misconceptions about how judgments, injunctions, and judicial precedent control real-world conduct and how litigation brings about legal reform. These misconceptions reached their nadir in Alabama in spring 2015. Guided by Chief Justice Roy Moore, Alabama officials properly declined to follow persuasive precedent, prompting unfortunate and inaccurate comparisons to George Wallace and Massive Resistance, and to Brown and desegregation. Second, we examine the pivotal but underappreciated role of stays pending appeal in constitutional litigation. In particular, we consider how denials of stays triggered concurrent races to the courts of appeals and to the altars. The Court\u27s transmission of signals through unexplained stays and denials of certiorari exacerbated the confusion in the lower courts and the states, highlighting a penumbra of what one scholar calls the Court\u27s shadow docket. Finally, we examine unsuccessful efforts by state attorneys general to move marriage cases out of federal court by initiating state-court litigation and urging federal abstention. This article makes a first contribution to the scholarly discussion of marriage equality by focusing on the critical but underdeveloped procedural nuances of high-stakes civil rights litigation. By considering the process of marriage equality, we better understand this societal evolution and future constitutional revolutions
A Comparison of Relativistic and Reader-Writer Locking Approaches to Shared Data Access
This paper explores the relationship between reader-writer locking and relativistic programming approaches to managing accesses to shared data. It demonstrates that by placing certain restrictions on writers, relativistic programming allows more concurrency than reader-writer locking while still providing the same isolation guarantees. Relativistic programming also allows for a straightforward model for reasoning about the correctness of programs that allow concurrent read-write accesses
Automated design of pneumatic soft grippers through design-dependent multi-material topology optimization
In recent years, soft robotic grasping has rapidly spread through the
academic robotics community and pushed into industrial applications. At the
same time, multimaterial 3D printing has become widely available, enabling
monolithic manufacture of devices containing rigid and elastic section. We
propose a novel design technique which leverages both of these technologies and
is able to automatically design bespoke soft robotic grippers for fruit-picking
and similar applications. We demonstrate the novel topology optimisation
formulation which generates multi-material soft gippers and is able to solve
both the internal and external pressure boundaries, and investigate methods to
produce air-tight designs. Compared to existing methods, it vastly expands the
searchable design space whilst increasing simulation accuracy
A 'MAP' to find high-performing soft robot designs: Traversing complex design spaces using MAP-elites and Topology Optimization
Soft robotics has emerged as the standard solution for grasping deformable
objects, and has proven invaluable for mobile robotic exploration in extreme
environments. However, despite this growth, there are no widely adopted
computational design tools that produce quality, manufacturable designs. To
advance beyond the diminishing returns of heuristic bio-inspiration, the field
needs efficient tools to explore the complex, non-linear design spaces present
in soft robotics, and find novel high-performing designs. In this work, we
investigate a hierarchical design optimization methodology which combines the
strengths of topology optimization and quality diversity optimization to
generate diverse and high-performance soft robots by evolving the design
domain. The method embeds variably sized void regions within the design domain
and evolves their size and position, to facilitating a richer exploration of
the design space and find a diverse set of high-performing soft robots. We
demonstrate its efficacy on both benchmark topology optimization problems and
soft robotic design problems, and show the method enhances grasp performance
when applied to soft grippers. Our method provides a new framework to design
parts in complex design domains, both soft and rigid
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