Constraining f(R) Gravity as a Scalar Tensor Theory

We search for viable f(R) theories of gravity, making use of the equivalence between such theories and scalar-tensor gravity. We find that models can be made consistent with solar system constraints either by giving the scalar a high mass or by exploiting the so-called chameleon effect. However, in both cases, it appears likely that any late-time cosmic acceleration will be observationally indistinguishable from acceleration caused by a cosmological constant. We also explore further observational constraints from, e.g., big bang nucleosynthesis and inflation.Comment: 15 pages, 5 figure

CRiBAC: Community-centric role interaction based access control model

As one of the most efficient solutions to complex and large-scale problems, multi-agent cooperation has been in the limelight for the past few decades. Recently, many research projects have focused on context-aware cooperation to dynamically provide complex services. As cooperation in the multi-agent systems (MASs) becomes more common, guaranteeing the security of such cooperation takes on even greater importance. However, existing security models do not reflect the agents' unique features, including cooperation and context-awareness. In this paper, we propose a Community-based Role interaction-based Access Control model (CRiBAC) to allow secure cooperation in MASs. To do this, we refine and extend our preliminary RiBAC model, which was proposed earlier to support secure interactions among agents, by introducing a new concept of interaction permission, and then extend it to CRiBAC to support community-based cooperation among agents. We analyze potential problems related to interaction permissions and propose two approaches to address them. We also propose an administration model to facilitate administration of CRiBAC policies. Finally, we present the implementation of a prototype system based on a sample scenario to assess the proposed work and show its feasibility. © 2012 Elsevier Ltd. All rights reserved

Guide for Controlling Cotton Insects in the High Plains, Rolling Plains and Trans-Pecos Areas of Texas.

8 p

Evaluation of Technology Concepts for Energy, Automation, and System State Awareness in Commercial Airline Flight Decks

A pilot-in-the-loop flight simulation study was conducted at NASA Langley Research Center to evaluate flight deck systems that (1) provide guidance for recovery from low energy states and stalls, (2) present the current state and expected future state of automated systems, and/or (3) show the state of flight-critical data systems in use by automated systems and primary flight instruments. The study was conducted using 13 commercial airline crews from multiple airlines, paired by airline to minimize procedural effects. Scenarios spanned a range of complex conditions and several emulated causal and contributing factors found in recent accidents involving loss of state awareness by pilots (e.g., energy state, automation state, and/or system state). Three new technology concepts were evaluated while used in concert with current state-of-the-art flight deck systems and indicators. The technologies include a stall recovery guidance algorithm and display concept, an enhanced airspeed control indicator that shows when automation is no longer actively controlling airspeed, and enhanced synoptic pages designed to work with simplified interactive electronic checklists. An additional synoptic was developed to provide the flight crew with information about the effects of loss of flight critical data. Data was collected via questionnaires administered at the completion of flight scenarios, audio/video recordings, flight data, head and eye tracking data, pilot control inputs, and researcher observations. This paper presents findings derived from the questionnaire responses and subjective data measures including workload, situation awareness, usability, and acceptability as well as analyses of two low-energy flight events that resulted in near-stall conditions

Keys To Profitable Cotton Production in the Rolling Plains.

8 p

Economic Implications of a Delayed Uniform Planting Date for Cotton Production in the Texas Rolling Plains.

40 p

Father involvement and socioeconomic disparities in child academic outcomes

OBJECTIVE This article explores whether father involvement can reduce socioeconomic disparities in child academic outcomes. BACKGROUND An emerging body of literature points to the benefits to children of involvement by low‐socioeconomic status (SES) fathers. Research has not systematically investigated whether differences in father involvement can account for SES‐based disparities in child outcomes. METHOD This study used data from 12,030 unique children from the 1998 Early Childhood Longitudinal Study. Using multiple regression models and novel simulation analyses, it investigated whether accounting for SES‐based differences in either the amount or effect of involvement by biological fathers explains gaps in reading scores, math scores, and rates of grade retention between low‐SES and high‐SES children. RESULTS Father residence, resident father school involvement, and a comprehensive index of nonresident father involvement were associated with better child academic outcomes. Associations between residence and nonresident father involvement and child outcomes were consistent for fathers in all SES quintiles. School involvement by low‐SES resident fathers was more beneficial than involvement by the highest SES fathers. Simulation analyses indicated that increasing the amount of involvement by low‐SES fathers to that of high‐SES fathers would result in minimal decreases in SES disparities in reading and math scores, but more sizeable decreases in rates of grade retention. CONCLUSION Increasing some types of father involvement may help to narrow academic gaps between low‐ and high‐SES children.Accepted manuscrip

'To live and die [for] Dixie': Irish civilians and the Confederate States of America

Around 20,000 Irishmen served in the Confederate army in the Civil War. As a result, they left behind, in various Southern towns and cities, large numbers of friends, family, and community leaders. As with native-born Confederates, Irish civilian support was crucial to Irish participation in the Confederate military effort. Also, Irish civilians served in various supporting roles: in factories and hospitals, on railroads and diplomatic missions, and as boosters for the cause. They also, however, suffered in bombardments, sieges, and the blockade. Usually poorer than their native neighbours, they could not afford to become 'refugees' and move away from the centres of conflict. This essay, based on research from manuscript collections, contemporary newspapers, British Consular records, and Federal military records, will examine the role of Irish civilians in the Confederacy, and assess the role this activity had on their integration into Southern communities. It will also look at Irish civilians in the defeat of the Confederacy, particularly when they came under Union occupation. Initial research shows that Irish civilians were not as upset as other whites in the South about Union victory. They welcomed a return to normalcy, and often 'collaborated' with Union authorities. Also, Irish desertion rates in the Confederate army were particularly high, and I will attempt to gauge whether Irish civilians played a role in this. All of the research in this paper will thus be put in the context of the Drew Gilpin Faust/Gary Gallagher debate on the influence of the Confederate homefront on military performance. By studying the Irish civilian experience one can assess how strong the Confederate national experiment was. Was it a nation without a nationalism

Supracubital perineurioma misdiagnosed as carpal tunnel syndrome: case report

BACKGROUND: Perineuriomas have been defined as tumorous lesions of the peripheral nerves which derive from perineurial cell proliferation and may be associated with abnormalities on chromosome 22. CASE PRESENTATION: Three years after a painful cubital vein procaine injection, a 33 year-old man developed a median nerve lesion, initially diagnosed as carpal tunnel syndrome. Symptoms progressed despite appropriate surgery. Clinical and electrophysiological re-evaluation revealed a fusiform mass at the distal upper arm, confirmed by MRI. Immunohistochemical studies classified the tumor as a mixed perineurioma and neuroma. CONCLUSIONS: Perineurioma mixed with neuroma may potentially caused by the previous trauma or cytotoxic effects of procaine

Emerging Technologies for Airplane State Awareness and Prediction

Loss of control in flight (LOC-I) is consistently the leading cause of fatal aircraft accidents. A study of LOC accidents and incidents, commissioned by the Commercial Aviation Safety Team (CAST) identified a growing trend in loss of Airplane State Awareness (ASA) by the flight crew. This has led to recommended safety enhancements that include flight deck technologies with the potential of enhancing flight crew awareness of airplane energy state. The goal of this research is to develop and evaluate technologies that predict and assess the future aircraft energy state and auto-flight configuration, and provide appropriate alerting to anticipated problematic auto-flight inputs, with the aim of enhancing pilots situational awareness