Gap bootstrap methods for massive data sets with an application to transportation engineering

In this paper we describe two bootstrap methods for massive data sets. Naive applications of common resampling methodology are often impractical for massive data sets due to computational burden and due to complex patterns of inhomogeneity. In contrast, the proposed methods exploit certain structural properties of a large class of massive data sets to break up the original problem into a set of simpler subproblems, solve each subproblem separately where the data exhibit approximate uniformity and where computational complexity can be reduced to a manageable level, and then combine the results through certain analytical considerations. The validity of the proposed methods is proved and their finite sample properties are studied through a moderately large simulation study. The methodology is illustrated with a real data example from Transportation Engineering, which motivated the development of the proposed methods.Comment: Published in at http://dx.doi.org/10.1214/12-AOAS587 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Internuclear gene silencing in Phytophthora infestans is established through chromatin remodelling

In the plant pathogen Phytophthora infestans, nuclear integration of inf1 transgenic DNA sequences results in internuclear gene silencing of inf1. Although silencing is regulated at the transcriptional level, it also affects transcription from other nuclei within heterokaryotic cells of the mycelium. Here we report experiments exploring the mechanism of internuclear gene silencing in P. infestans. The DNA methylation inhibitor 5-azacytidine induced reversion of the inf1-silenced state. Also, the histone deacetylase inhibitor trichostatin-A was able to reverse inf1 silencing. inf1-expression levels returned to the silenced state when the inhibitors were removed except in non-transgenic inf1-silenced strains that were generated via internuclear gene silencing, where inf1 expression was restored permanently. Therefore, inf1-transgenic sequences are required to maintain the silenced state. Prolonged culture of non-transgenic inf1-silenced strains resulted in gradual reactivation of inf1 gene expression. Nuclease digestion of inf1-silenced and non-silenced nuclei showed that inf1 sequences in silenced nuclei were less rapidly degraded than non-silenced inf1 sequences. Bisulfite sequencing of the endogenous inf1 locus did not result in detection of any cytosine methylation. Our findings suggest that the inf1-silenced state is based on chromatin remodelling

Drug resistance outcomes of long-term ART with tenofovir disoproxil fumarate in the absence of virological monitoring

Objectives: The resistance profiles of patients receiving long-term ART in sub-Saharan Africa have been poorly described. This study obtained a sensitive assessment of the resistance patterns associated with long-term tenofovir-based ART in a programmatic setting where virological monitoring is yet to become part of routine care. Methods: We studied subjects who, after a median of 4.2 years of ART, replaced zidovudine or stavudine with tenofovir disoproxil fumarate while continuing lamivudine and an NNRTI. Using deep sequencing, resistance-associated mutations (RAMs) were detected in stored samples collected at tenofovir introduction (T0) and after a median of 4.0 years (T1). Results: At T0, 19/87 (21.8%) subjects showed a detectable viral load and 8/87 (9.2%) had one or more major NNRTI RAMs, whereas 82/87 (94.3%) retained full tenofovir susceptibility. At T1, 79/87 (90.8%) subjects remained on NNRTI-based ART, 5/87 (5.7%) had introduced lopinavir/ritonavir due to immunological failure, and 3/87 (3.4%) had interrupted ART. Whilst 68/87 (78.2%) subjects maintained or achieved virological suppression between T0 and T1, a detectable viral load with NNRTI RAMs at T0 predicted lack of virological suppression at T1. Each treatment interruption, usually reflecting unavailability of the dispensary, doubled the risk of T1 viraemia. Tenofovir, lamivudine and efavirenz selected for K65R, K70E/T, L74I/V and Y115F, alongside M184V and multiple NNRTI RAMs; this resistance profile was accompanied by high viral loads and low CD4 cell counts. Conclusions: Viraemia on tenofovir, lamivudine and efavirenz led to complex resistance patterns with implications for continued drug activity and risk of onward transmission

Supporting independent living for older adults; employing a visual based fall detection through analysing the motion and shape of the human body

Falls are one of the greatest risks for older adults living alone at home. This paper presents a novel visual-based fall detection approach to support independent living for older adults through analysing the motion and shape of the human body. The proposed approach employs a new set of features to detect a fall. Motion information of a segmented silhouette when extracted can provide a useful cue for classifying different behaviours, while variation in shape and the projection histogram can be used to describe human body postures and subsequent fall events. The proposed approach presented here extracts motion information using best-fit approximated ellipse and bounding box around the human body, produces projection histograms and determines the head position over time, to generate 10 features to identify falls. These features are fed into a multilayer perceptron neural network for fall classification. Experimental results show the reliability of the proposed approach with a high fall detection rate of 99.60% and a low false alarm rate of 2.62% when tested with the UR Fall Detection dataset. Comparisons with state of the art fall detection techniques show the robustness of the proposed approach

Pesticidal Effects of Extracts from Hyptis suaveolens and Hyptis spicigera on Cowpea Weevils

This experimental research was conducted with the view of determining the effectiveness of Hyptis suaveolens and Hyptis spicigera extracts on cowpea seeds in deterring the feeding habit and life span of cowpea weevils. Masses of 400 and 500 grammes of pulverized samples of the two plants, Hyptis suaveolens and Hyptis spicigera were separately extracted by percolation with 2200 millilitres of 95% ethanol respectively. The percolates were evaporated to dryness at room temperature to give crude extracts of both plants which were each subjected to a partition process. Soluble solvent extracts of the two plants were applied on cowpea seeds and subjected to cowpea weevils by two-choice feeding deterrent method. The chloroform soluble extracts were found to be most active extracts of both plants with the least percentage consumption indices and higher percentage mortalities. This was a clear indication that these chloroform soluble extracts contained most of the toxic component(s) of the plants which can be used to protect cowpea seeds to some period of time. The study tasks the Ministry of Food and Agriculture to consider providing funding and further research into the use of the pesticides from these plant extracts to maintain the buoyancy of biodiversity as well as the environment in Ghana

Evaluation of herbs as potential alternatives for bear bile and rhino horn used in traditional Chinese medicines: chemical and biological analysis.

There is currently an unsustainable rate of exploitation of certain species of plants and animals for use in traditional medicines. Bear bile and rhino horn are derived from endangered species and are traditionally combined with medicinal herbs as anti-bacterial and anti-inflammatory agents. This study was designed to assess herbs for use as possible alternatives for these two products. Herbs were selected based on their traditional use as antiinflammatory and anti-bacterial agents. Chemical methods were used to confirm the plant species of the herbs and to measure concentrations of metals and pesticide residues as a means for assessing their quality. Antibacterial activities were determined using a direct bioautography technique. Anti-inflammatory activities of the herb extracts and isolated compounds were ascertained using an in vitro nuclear factor kappaB (NF-KB) activity, as assessed by IL-6 luciferase gene reporter assay. A novel assay was developed to estimate drug-herb interactions by measuring the effects of selected herbs and drugs on the production of eicosatrienoic acids from hepatic cytochrome P450 (CYP450) metabolism of arachidonic acid. In addition, CYP3A4 enzyme assays were conducted. The pesticide residue and heavy metal concentrations of the tested herbs was found not to exceed the existing legally permitted concentrations in foodstuffs, but the rhino horn sample contained elevated levels of Cd, Pb, Hg and Zn. Rhino horn was not found to be an effective anti-bacterial or anti-inflammatory agent In the assays used in this study. Seventeen herbs demonstrated anti-bacterial activity. Also, nine herbs demonstrated inhibitory NF-KB activity. Preliminary results indicate that co-administration of Scutel/aria baicalensis, Salvia miltiorrhiza, Rehmann/a glutinosa or Coptidis Rhizoma with drugs metabolised by CYP3A4, could lead to possible drug-herb interactions. Based on the Information obtained in these studies nine herbs are proposed as alternatives to rhino horn; eight herbs and two Kampo medicines are proposed as alternatives to bear bile

Is diversity good?

Prominent ethical and policy issues such as affirmative action and female enrollment in science and engineering revolve around the idea that diversity is good. However, even though diversity is an ambiguous concept, a precise definition is seldom provided. We show that diversity may be construed as a factual description, a craving for symmetry, an intrinsic good, an instrumental good, a symptom, or a side effect. These acceptions differ vastly in their nature and properties. The first one cannot lead to any action and the second one is mistaken. Diversity as intrinsic good is a mere opinion, which cannot be concretely applied; moreover, the most commonly invoked forms of diversity (sexual and racial) are not intrinsically good. On the other hand, diversity as instrumental good can be evaluated empirically and can give rise to policies, but these may be very weak. Finally, symptoms and side effects are not actually about diversity. We consider the example of female enrollment in science and engineering, interpreting the various arguments found in the literature in light of this polysemy. Keywords: ethics, policy, higher education, female students, minority students, affirmative actionComment: 7 page

Madness decolonized?: Madness as transnational identity in Gail Hornstein’s Agnes’s Jacket

The US psychologist Gail Hornstein’s monograph Agnes’s Jacket: A Psychologist’s Search for the Meanings of Madness (2009) is an important intervention in the identity politics of the mad movement. Hornstein offers a resignified vision of mad identity that embroiders the central trope of an “anti-colonial” struggle to reclaim the experiential world “colonized” by psychiatry. A series of literal and figurative appeals make recourse to the inner world and (corresponding) cultural world of the mad, as well as to the ethno-symbolic cultural materials of dormant nationhood. This rhetoric is augmented by a model in which the mad comprise a diaspora without an origin, coalescing into a single transnational community. The mad are also depicted as persons displaced from their metaphorical homeland, the “inner” world “colonized” by the psychiatric regime. There are a number of difficulties with Hornstein’s rhetoric, however. Her “ethnicity-and-rights” response to the oppression of the mad is symptomatic of Western parochialism, while her proposed transmutation of putative psychopathology from limit upon identity to parameter of successful identity is open to contestation. Moreover, unless one accepts Hornstein’s porous vision of mad identity, her self-ascribed insider status in relation to the mad community may present a problematic “re-colonization” of mad experience

Personal identity (de)formation among lifestyle travellers: A double-edged sword?

This article explores the personal identity work of lifestyle travellers – individuals for whom extended leisure travel is a preferred lifestyle that they return to repeatedly. Qualitative findings from in-depth semi-structured interviews with lifestyle travellers in northern India and southern Thailand are interpreted in light of theories on identity formation in late modernity that position identity as problematic. It is suggested that extended leisure travel can provide exposure to varied cultural praxes that may contribute to a sense of social saturation. Whilst a minority of the respondents embraced a saturation of personal identity in the subjective formation of a cosmopolitan cultural identity, several of the respondents were paradoxically left with more identity questions than answers as the result of their travels