Nonclassicality of a photon-subtracted Gaussian field

Published versio

An Economic analysis of the potential for precision farming in UK cereal production

The results from alternative spatial nitrogen application studies are analysed in economic terms and compared to the costs of precision farming hardware, software and other services for cereal crops in the UK. At current prices, the benefits of variable rate application of nitrogen exceed the returns from a uniform application by an average of £22 ha−1 The cost of the precision farming systems range from £5 to £18 ha−1 depending upon the system chosen for an area of 250 ha. The benefits outweigh the associated costs for cereal farms in excess of 80 ha for the lowest price system to 200–300 ha for the more sophisticated systems. The scale of benefits obtained depends upon the magnitude of the response to the treatment and the proportion of the field that will respond. To be cost effective, a farmed area of 250 ha of cereals, where 30% of the area will respond to variable treatment, requires an increase in crop yield in the responsive areas of between 0·25 and 1.00 t ha−1 (at £65 t−1) for the basic and most expensive precision farming systems, respectively

O limite de educação especial do Texas: Explorando o atraso e a negação de apoio a alunos com deficiências do Estado

State accountability systems have been a primary school reform initiative in the U.S. for the past twenty years, but often produce unintended negative consequences. In 2004, the Texas Education Agency (TEA) implemented the Performance Based Monitoring and Analysis System (PBMAS) which included an accountability indicator focused on the percentage of students found eligible for special education under the Individuals with Disabilities Education Act (IDEA), the nation’s special education law. From 2004 through 2016, the percentage of students found eligible for special education in Texas declined significantly, while the national rate held constant. Eventually, the U.S. Department of Education (ED) investigated TEA and the statewide implementation of IDEA. The purpose of this study is two-fold: (a) to evaluate the potential impact of the the PBMAS indicator on manipulation of special education identification practices; and (b) to describe how the indicator may have influenced school and district personnel. We highlight several concerning trends in state and district data and, through an analysis of publicly available reports from the ED, show how district and school personnel knowingly and unknowingly acted in ways that delayed and denied special education to potentially eligible students. We conclude with recommendations for TEA and implications for future research and policy. Los sistemas estatales de rendición de cuentas han sido una iniciativa de reforma de la escuela primaria en los Estados Unidos durante los últimos veinte años, pero a menudo producen consecuencias negativas no deseadas. En 2004, la Texas Education Agency (TEA) implementó el Performance Based Monitoring and Analysis System (PBMAS) que incluía un indicador de responsabilidad centrado en el porcentaje de estudiantes elegibles para educación especial bajo el Individuals with Disabilities Education Act (IDEA), ley de educación especial de la nación. Desde 2004 hasta 2016, el porcentaje de estudiantes elegibles para educación especial en Texas disminuyó significativamente, mientras que la tasa nacional se mantuvo constante. Finalmente, el Departamento de Educación de los Estados Unidos (ED) investigó la TEA y la implementación estatal de IDEA. El propósito de este estudio es doble: (a) evaluar el impacto potencial del indicador PBMAS en la manipulación de las prácticas de identificación de educación especial; y (b) describir cómo el indicador puede haber influido en el personal de la escuela y del distrito. Destacamos varias tendencias concernientes a los datos del estado y del distrito y, a través de un análisis de los informes de ED disponibles al público, mostramos cómo el distrito y el personal escolar actuaron a sabiendas e inconscientemente de una manera que retrasó y negó la educación especial a los estudiantes potencialmente elegibles. Concluimos con recomendaciones para TEA e implicaciones para futuras investigaciones y políticas.Os sistemas de responsabilização do Estado têm sido uma iniciativa da reforma do ensino primário nos Estados Unidos nos últimos vinte anos, mas muitas vezes produzem consequências negativas não intencionais. Em 2004, a Texas Education Agency (TEA) implementou o Performance Based Monitoring and Analysis System (PBMAS), que incluiu um indicador de prestação de contas focado na porcentagem de estudantes elegíveis para educação especial sob a  Individuals with Disabilities Education Act (IDEA), a lei de educação especial do país. De 2004 a 2016, a porcentagem de estudantes qualificados para educação especial no Texas diminuiu significativamente, enquanto a taxa nacional permaneceu constante. Finalmente, o Departamento de Educação dos Estados Unidos (DE) investigou o TEA e a implementação estadual do IDEA. O propósito deste estudo é duplo: (a) avaliar o impacto potencial do indicador PBMAS na manipulação de práticas de identificação de educação especial; e (b) descrever como o indicador pode ter influenciado o pessoal da escola e do distrito. Destacamos várias tendências relativas a dados estaduais e distritais e, por meio de uma análise de relatórios de DE disponíveis ao público, mostramos como os funcionários do distrito e da escola agiram consciente e inconscientemente de uma maneira que atrasou e negou a educação. especial para alunos potencialmente elegíveis. Concluímos com recomendações para ASD e implicações para futuras pesquisas e políticas

Thermal convection in fluidized granular systems

Thermal convection is observed in molecular dynamic simulation of a fluidized granular system of nearly elastic hard disks moving under gravity, inside a rectangular box. Boundaries introduce no shearing or time dependence, but the energy injection comes from a slip (shear-free) thermalizing base. The top wall is perfectly elastic and lateral boundaries are either elastic or periodic. The observed convection comes from the effect of gravity and the spontaneous granular temperature gradient that the system dynamically develops.Comment: 4 pages, 5 figure

Introduction to the computational structural mechanics testbed

The Computational Structural Mechanics (CSM) testbed software system based on the SPAR finite element code and the NICE system is described. This software is denoted NICE/SPAR. NICE was developed at Lockheed Palo Alto Research Laboratory and contains data management utilities, a command language interpreter, and a command language definition for integrating engineering computational modules. SPAR is a system of programs used for finite element structural analysis developed for NASA by Lockheed and Engineering Information Systems, Inc. It includes many complementary structural analysis, thermal analysis, utility functions which communicate through a common database. The work on NICE/SPAR was motivated by requirements for a highly modular and flexible structural analysis system to use as a tool in carrying out research in computational methods and exploring computer hardware. Analysis examples are presented which demonstrate the benefits gained from a combination of the NICE command language with a SPAR computational modules

Prevalence and causes of low vision and blindness in northern KwaZulu

A survey of the prevalence of blindness and low vision was conducted in the Ingwavuma district of KwaZulu to assess the effectiveness of existing eye care facilities in the prevention and treatInent of impaired vision and blindness. One hundred subjects from each of 60 randomly selected clusters (N =6 090) were screened. Of these, 293 were identified and referred to an ophthalmologist for examination. Of the 268 (91,5%) examined, 241 were found to have visual impairment. Sixty-one of these people were blind, 85 had low vision, 61 were blind in one eye but had normal vision in the other, and 34 had low vision in one eye but normal vision in the other. The prevalence of blindness was 1,0% (95% confidence interval 0,7 - 1,2%), and the prevalence of impaired vision was 1,4% (95% confidence interval 1,1 - 1,7%). Age-related cataract (59,0%) and chronic glaucom.a (22,9%) were the two m.ain causes of blindness. Age-related cataract (75,3%), refractive error (10,0%) and chronic glaucom.a (4,7%) were the main causes of im.paired vision. Existing eye care services for the region have reduced the prevalence of blindness by only 7,0%. The training of ophthalmic nurses and the establishment of a sight-saver clinic in the area are necessary to reduce the prevalence of low vision and blindness

Posttransplant lymphoproliferative disorders in neuronal xenotransplanted macaques

Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations that occur in the setting of depressed T-cell function due to immunosuppressive therapy used following solid organ transplantation, hematopoietic stem cell transplantation, and also xenotransplantation. In the present study, 28 immunosuppressed parkinsonian Macaca fascicularis were intracerebrally injected with wild-type or CTLA4-Ig transgenic porcine xenografts to identify a suitable strategy to enable long-term cell survival, maturation, and differentiation. Nine of 28 (32%) immunosuppressed primates developed masses compatible with PTLD, located mainly in the gastrointestinal tract and/or nasal cavity. The masses were classified as monomorphic PTLD according to the World Health Organization classification. Immunohistochemistry and polymerase chain reaction (PCR) analyses revealed that the PTLDs were associated with macaca lymphocryptovirus as confirmed by double-labeling immunohistochemistry for CD20 and Epstein-Barr nuclear antigen 2 (EBNA-2), where the viral protein was located within the CD20+ neoplastic B cells. In sera from 3 distinct phases of the experimental life of the primates, testing by quantitative PCR revealed a progression of the viral load that paralleled the PTLD progression and no evidence of zoonotic transmission of porcine lymphotropic herpesvirus through xenoneuronal grafts. These data suggest that monitoring the variation of macaca lymphocryptovirus DNA in primates could be used as a possible early diagnostic tool for PTLD progression, allowing preemptive treatment such as immunosuppression therapy reduction

Egalitarian justice and expected value

According to all-luck egalitarianism, the differential distributive effects of both brute luck, which defines the outcome of risks which are not deliberately taken, and option luck, which defines the outcome of deliberate gambles, are unjust. Exactly how to correct the effects of option luck is, however, a complex issue. This article argues that (a) option luck should be neutralized not just by correcting luck among gamblers, but among the community as a whole, because it would be unfair for gamblers as a group to be disadvantaged relative to non-gamblers by bad option luck; (b) individuals should receive the warranted expected results of their gambles, except insofar as individuals blamelessly lacked the ability to ascertain which expectations were warranted; and (c) where societal resources are insufficient to deliver expected results to gamblers, gamblers should receive a lesser distributive share which is in proportion to the expected results. Where all-luck egalitarianism is understood in this way, it allows risk-takers to impose externalities on non-risk-takers, which seems counterintuitive. This may, however, be an advantage as it provides a luck egalitarian rationale for assisting ‘negligent victims’

A Research-Based Curriculum for Teaching the Photoelectric Effect

Physics faculty consider the photoelectric effect important, but many erroneously believe it is easy for students to understand. We have developed curriculum on this topic including an interactive computer simulation, interactive lectures with peer instruction, and conceptual and mathematical homework problems. Our curriculum addresses established student difficulties and is designed to achieve two learning goals, for students to be able to (1) correctly predict the results of photoelectric effect experiments, and (2) describe how these results lead to the photon model of light. We designed two exam questions to test these learning goals. Our instruction leads to better student mastery of the first goal than either traditional instruction or previous reformed instruction, with approximately 85% of students correctly predicting the results of changes to the experimental conditions. On the question designed to test the second goal, most students are able to correctly state both the observations made in the photoelectric effect experiment and the inferences that can be made from these observations, but are less successful in drawing a clear logical connection between the observations and inferences. This is likely a symptom of a more general lack of the reasoning skills to logically draw inferences from observations.Comment: submitted to American Journal of Physic

Network-wide Configuration Synthesis

Computer networks are hard to manage. Given a set of high-level requirements (e.g., reachability, security), operators have to manually figure out the individual configuration of potentially hundreds of devices running complex distributed protocols so that they, collectively, compute a compatible forwarding state. Not surprisingly, operators often make mistakes which lead to downtimes. To address this problem, we present a novel synthesis approach that automatically computes correct network configurations that comply with the operator's requirements. We capture the behavior of existing routers along with the distributed protocols they run in stratified Datalog. Our key insight is to reduce the problem of finding correct input configurations to the task of synthesizing inputs for a stratified Datalog program. To solve this synthesis task, we introduce a new algorithm that synthesizes inputs for stratified Datalog programs. This algorithm is applicable beyond the domain of networks. We leverage our synthesis algorithm to construct the first network-wide configuration synthesis system, called SyNET, that support multiple interacting routing protocols (OSPF and BGP) and static routes. We show that our system is practical and can infer correct input configurations, in a reasonable amount time, for networks of realistic size (> 50 routers) that forward packets for multiple traffic classes.Comment: 24 Pages, short version published in CAV 201