Induction of First-Order Decision Lists: Results on Learning the Past Tense of English Verbs

This paper presents a method for inducing logic programs from examples that learns a new class of concepts called first-order decision lists, defined as ordered lists of clauses each ending in a cut. The method, called FOIDL, is based on FOIL (Quinlan, 1990) but employs intensional background knowledge and avoids the need for explicit negative examples. It is particularly useful for problems that involve rules with specific exceptions, such as learning the past-tense of English verbs, a task widely studied in the context of the symbolic/connectionist debate. FOIDL is able to learn concise, accurate programs for this problem from significantly fewer examples than previous methods (both connectionist and symbolic).Comment: See http://www.jair.org/ for any accompanying file

The effects of organic farming on the soil physical environment

The aim of this research was to investigate the effects of organic farming practices on the development of soil physical properties, and in particular, soil structure in comparison with conventional agricultural management. The soil structure of organically and conventionally managed soils at one site was compared in a quantitative manner at different scales of observations using image analysis. Key soil physical and chemical properties were measured as well as the pore fractal geometry to characterise pore roughness. Organically managed soils had higher organic matter content and provided a more stable soil structure than conventionally managed soils. The higher porosity (%) at the macroscale in soil under conventional management was due to fewer larger pores while mesoand microscale porosity was found to be greater under organic management. Organically managed soils typically provided spatially well distributed pores of all sizes and of greater roughness compared to those under conventional management. These variations in the soil physical environment are likely to impact significantly on the performance of these soils for a number of key processes such as crop establishment and water availabilit

Highly electronegative metallic contacts to semiconductors using polymeric sulfur nitride

The Schottky barriers formed on n‐ZnS and n‐ZnSe by polymeric sulfur nitride have been compared to barriers formed by Au. Barrier energies as determined by photoresponse, current‐voltage, and capacitance‐voltage methods show that (SN)_x is approximately 1.0 eV higher than Au on n‐ZnS and 0.3–0.4 eV higher than Au on n‐ZnSe. We believe that this is the first report of any metallic contact more electronegative than Au

Masses, luminosities and dynamics of galactic molecular clouds

Star formation in galaxies takes place in molecular clouds and the Milky Way is the only galaxy in which it is possible to resolve and study the physical properties and star formation activity of individual clouds. The masses, luminosities, dynamics, and distribution of molecular clouds, primarily giant molecular clouds in the Milky Way are described and analyzed. The observational data sets are the Massachusetts-Stony Brook CO Galactic Plane Survey and the IRAS far IR images. The molecular mass and infrared luminosities of glactic clouds are then compared with the molecular mass and infrared luminosities of external galaxies

Using local evidence to inform public health priorities for lesbian and bisexual women’s sexual health

The 2010 National Women’s Health Policy (NWHP) acknowledged for the first time that lesbian and bisexual women may be at risk of poor health outcomes. It called for “information and access to services to sexual health, reproductive health, safe sex practices, screening and maternal health”. A lack of systematic, nuanced research on the sexual health of Australian lesbian and bisexual women has resulted in lack of data and difficulty in understanding the needs of and how best to respond to this group. AIM To identify the sexual health needs of lesbian and bisexual wome

Statistical Mechanics of Semi-Supervised Clustering in Sparse Graphs

We theoretically study semi-supervised clustering in sparse graphs in the presence of pairwise constraints on the cluster assignments of nodes. We focus on bi-cluster graphs, and study the impact of semi-supervision for varying constraint density and overlap between the clusters. Recent results for unsupervised clustering in sparse graphs indicate that there is a critical ratio of within-cluster and between-cluster connectivities below which clusters cannot be recovered with better than random accuracy. The goal of this paper is to examine the impact of pairwise constraints on the clustering accuracy. Our results suggests that the addition of constraints does not provide automatic improvement over the unsupervised case. When the density of the constraints is sufficiently small, their only impact is to shift the detection threshold while preserving the criticality. Conversely, if the density of (hard) constraints is above the percolation threshold, the criticality is suppressed and the detection threshold disappears.Comment: 8 pages, 4 figure

Women in contact with the gay and lesbian community in Sydney: Report of the Sydney Women and Sexual Health (SWASH) Survey 2006, 2008, 2010 and 2012

The Sydney Women and Sexual Health (SWASH) survey is run by a collaboration of ACON and researchers at the University of Sydney (prior to 2009, researchers were based at the University of New South Wales). It was first carried out in 1996, initiated by workers from two ACON projects, Women Partners of Gay and Bisexual Men and the Gay and Lesbian Injecting Drug Use Project, who were faced with a lack of empirical evidence on which to base their intervention work. The survey is regularly revised to reflect the needs of the community and knowledge deficits identified through research literature. Over its lifetime, SWASH has become a comprehensive survey of sexual health and wellbeing, violence, mental health and levels of psychological distress, and a number of other important health issues relevant to lesbian, bisexual and queer (LBQ) women, such as tobacco use, illicit drug use, alcohol consumption, and cancer screening behaviours. Where possible, questions have been used from established national surveys such as the Australian Health Survey, National Drug Strategy Household Survey, Australian Study of Health and Relationships, and Australian Longitudinal Survey of Women’s Health. While research on LBQ women’s health and wellbeing has increased since the birth of the survey, epidemiological data on sexual health, mental health, experiences of abuse and violence and behaviours such as screening, illicit drug use, alcohol and smoking that can leave women vulnerable to adverse health outcomes, is still inconsistent. Moreover, as long as the inclusion of sexuality questions in large epidemiological surveys remains patchy or data is reported only by sexuality and not by sexuality and gender, SWASH provides a unique and important source of health-related information about Australian LBQ women. This report presents results from surveys conducted at the Sydney Gay and Lesbian Mardi Gras Fair Day and other community events and venues during the Sydney Gay and Lesbian Mardi Gras seasons in 2006, 2008, 2010 and 2012

Soil strength influences wheat root interactions with soil macropores

Deep rooting is critical for access to water and nutrients found in subsoil. However, damage to soil structure and the natural increase in soil strength with depth, often impedes root penetration. Evidence suggests that roots use macropores (soil cavities greater than 75μm) to bypass strong soil layers. If roots have to exploit structures, a key trait conferring deep rooting will be the ability to locate existing pore networks; a trait called trematotropism.In this study, artificial macropores were created in repacked soil columns at bulk densities of 1.6g cm‐3 and 1.2g cm‐3, representing compact and loose soil. Near isogenic lines of wheat, Rht‐B1a and Rht‐B1c, were planted and root‐macropore interactions were visualized and quantified using X‐ray Computed Tomography.In compact soil, 68.8% of root‐macropore interactions resulted in pore colonisation, compared to 12.5% in loose soil. Changes in root growth trajectory following pore interaction were also quantified, with 21.0% of roots changing direction (±3°) in loose soil compared to 76.0% in compact soil.These results indicate colonisation of macropores is an important strategy of wheat roots in compacted subsoil. Management practices to reduce subsoil compaction and encourage macropore formation could offer significant advantage in helping wheat roots penetrate deeper into subsoil

An oxygen-rich atmosphere or systemic fluoxetine extend the time to respiratory arrest in a rat model of obstructive apnea

© 2019 Elsevier Inc. Audiogenic seizure-prone mice can be protected from seizure-associated death by exposure to an oxygen atmosphere or treatment with selective serotonergic reuptake inhibitors (SSRIs). We have shown previously in a rat model that epileptic seizure activity can spread through brainstem areas to cause sufficient laryngospasm for obstructive apnea and that the period of seizure-associated obstructive apnea can last long enough for respiratory arrest to occur. We hypothesized that both the oxygen-rich atmosphere and SSRIs function by prolonging the time to respiratory arrest, thus ensuring that seizure activity stops before the point of respiratory arrest to allow recovery of respiratory function. To test this hypothesis, we evaluated each preventative treatment in a rat model of controlled airway occlusion where the times to respiratory arrest can be measured. Adult male Sprague Dawley rats (median age = 66 days) were studied in the absence of any seizure activity. By directly studying responses to controlled airway occlusion, rather than airway occlusion secondary to seizure activity, we could isolate the effects of manipulations that might prolong respiratory arrest from the effects of those manipulations on seizure intensity. All group sizes were ≥ 8 animals per group. We found that both oxygen exposure and fluoxetine significantly increased the time to respiratory arrest by up to 65% (p \u3c .0001 for 5 min oxygen exposure; p = .031 for 25 mg/kg fluoxetine tested 60 min after injection) and, given that neither treatment has been shown to significantly alter seizure duration, these increases can account for the protection of either manipulation against death in sudden death models. Importantly, we found that 30 s of exposure to oxygen produced nearly the same protection as 5 min exposure suggesting that oxygen exposure could start after a seizure starts (p = .0012 for 30 s oxygen exposure). Experiments with 50% oxygen/50% air mixtures indicate that the oxygen concentration needs to be above about 60% to ensure that times to respiratory arrest will always be longer than a period of seizure-induced airway occlusion. Selective serotonin reuptake inhibitors, while instructive with regard to mechanism, require impractical dosing and may carry additional risk in the form of greater challenges for resuscitation. We conclude that oxygen exposure or SSRI treatment prevent seizure associated death by sufficiently prolonging the time to respiratory arrest so that respiratory function can recover after the seizure abates and eliminates the stimulus for seizure-induced apnea