338 research outputs found
Improve the performance of transfer learning without fine-tuning using dissimilarity-based multi-view learning for breast cancer histology images
Breast cancer is one of the most common types of cancer and leading
cancer-related death causes for women. In the context of ICIAR 2018 Grand
Challenge on Breast Cancer Histology Images, we compare one handcrafted feature
extractor and five transfer learning feature extractors based on deep learning.
We find out that the deep learning networks pretrained on ImageNet have better
performance than the popular handcrafted features used for breast cancer
histology images. The best feature extractor achieves an average accuracy of
79.30%. To improve the classification performance, a random forest
dissimilarity based integration method is used to combine different feature
groups together. When the five deep learning feature groups are combined, the
average accuracy is improved to 82.90% (best accuracy 85.00%). When handcrafted
features are combined with the five deep learning feature groups, the average
accuracy is improved to 87.10% (best accuracy 93.00%)
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Projected WIMP sensitivity of the LUX-ZEPLIN dark matter experiment
LUX-ZEPLIN (LZ) is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with weakly interacting massive particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6-tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above 1.4×10-48 cm2 for a 40 GeV/c2 mass WIMP. Additionally, a 5σ discovery potential is projected, reaching cross sections below the exclusion limits of recent experiments. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of 2.3×10-43 cm2 (7.1×10-42 cm2) for a 40 GeV/c2 mass WIMP is expected. With underground installation well underway, LZ is on track for commissioning at SURF in 2020
Simulations of events for the LUX-ZEPLIN (LZ) dark matter experiment
The LUX-ZEPLIN dark matter search aims to achieve a sensitivity to the WIMP-nucleon spin-independent cross-section down to (1–2)×10−12 pb at a WIMP mass of 40 GeV/c2. This paper describes the simulations framework that, along with radioactivity measurements, was used to support this projection, and also to provide mock data for validating reconstruction and analysis software. Of particular note are the event generators, which allow us to model the background radiation, and the detector response physics used in the production of raw signals, which can be converted into digitized waveforms similar to data from the operational detector. Inclusion of the detector response allows us to process simulated data using the same analysis routines as developed to process the experimental data
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Projected sensitivity of the LUX-ZEPLIN experiment to the 0νββ decay of Xe 136
The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double β decay search in parallel to the main science goal of discovering dark matter particle interactions. We report the expected LZ sensitivity to Xe136 neutrinoless double β decay, taking advantage of the significant (>600 kg) Xe136 mass contained within the active volume of LZ without isotopic enrichment. After 1000 live-days, the median exclusion sensitivity to the half-life of Xe136 is projected to be 1.06×1026 years (90% confidence level), similar to existing constraints. We also report the expected sensitivity of a possible subsequent dedicated exposure using 90% enrichment with Xe136 at 1.06×1027 years
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Relationship between early development of spelling and reading
The research reported in this thesis examined the relationship between beginning spelling and reading. More specifically, it focussed on the relationship between the development of early reading and spelling in a context where the approach to early reading instruction includes systematic phonological awareness and decoding instruction. A critical assumption made by proponents of developmental early literacy models is that transfer of skills and knowledge from reading to spelling will occur spontaneously and without formal instruction (Frith, 1980). By contrast instruction-centred approaches make the assumption that there are critical pre-requisite skills that can and should be taught explicitly (Carnine, Silbert & Kameenui, 1997). The difference between these approaches is highlighted in the treatment of invented spelling, a popular activity in Western Australian junior primary classes. A series of studies was undertaken to examine the effect on invented and standard spelling performance of teaching Year 1 children phonological awareness and the strategy of sounding out words. Data were gathered from a range of settings using different research tools. The relationship between phonological awareness and beginning reading and spelling performance was explored initially through a single case study. A post-hoc study was then undertaken with a cohort of students who had received systematic decoding instruction to examine whether proficiency in the decoding of nonwords was related to spelling performance. This permitted an analysis of common sub-skills of decoding and encoding. In the main study the effect on different aspects of reading and spelling performance of using Let\u27s Decode, an approach that includes explicit phonological awareness and systematic decoding instruction, was investigated. In addition, an analysis was made of whether students who received explicit instruction in skills known to contribute to beginning reading and spelling produced superior invented spelling samples. A qualitative analysis was made of the. pre and post invented spelling tests of two pairs of students from the control and intervention groups matched on invented spelling and phonological awareness skills at the beginning of the year, and re tested at the end of Year 1. The final research question involved a single-subject research design to examine the effect of explicit instruction in isolating phonemes in words and prompts to \u27listen for sounds\u27 prior to, and during, the process of spelling words. The single case study revealed a child who was regarded as a competent speller and reader but who could only read words in a familiar context and who had developed a strategy for spelling words based on copying an adult model. This was interpreted as evidence supporting the need for phonological awareness instruction as a pre-requisite for spelling. The post-hoc analysis of a class of students who had received systematic decoding instruction showed that no student classified as a \u27good decoder\u27 could also be classified as a \u27poor speller\u27. This result was considered evidence of a strong link between the phonological knowledge that is required to decode and the role of alphabetic knowledge in spelling. The main study revealed phonological awareness and systematic decoding instruction was associated with superior invented and conventional spelling and reading performance on all reading and spelling measures. Of particular importance was the finding that students who commenced the study with very weak phonological awareness and who subsequently received systematic phonological and decoding instruction showed greater gains in invented spelling than matched students in the control condition. The single subject design showed the effectiveness of phonological awareness individualised instruction on invented spelling for weak students from both intervention and control conditions. It was concluded that the ability to invent spelling is improved when students receive explicit instruction in phonological awareness and systematic decoding but that some students, namely those with persistent weakness in phonological awareness, also require explicit prompts to apply their alphabetic knowledge to spelling words. The implications for instruction of these findings are discussed
Projected Range Contractions of European Protected Oceanic Montane Plant Communities: Focus on Climate Change Impacts Is Essential for Their Future Conservation
Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the northwest hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1) oceanic montane bryophytes and vascular plants; 2) species belonging to different montane plant communities; 3) species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need significantly greater focus on potential climate change impacts, including models with higher-resolution species distribution and environmental data, to aid these communities’ long-term survival
Muscle protein metabolism in neonatal alloxan-administered rats: effects of continuous and intermittent swimming training
<p>Abstract</p> <p>Background</p> <p>This study aimed to examine the effects of intermittent and continuous swimming training on muscle protein metabolism in neonatal alloxan-administered rats.</p> <p>Methods</p> <p>Wistar rats were used and divided into six groups: sedentary alloxan (SA), sedentary control (SC), continuous trained alloxan (CA), intermittent trained alloxan (IA), continuous trained control (CC) and intermittent trained control (IC). Alloxan (250 mg/kg body weight) was injected into newborn rats at 6 days of age. The continuous training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 5% of body weight; uninterrupted swimming for 1 h/day, five days a week. The intermittent training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 15% of body weight; 30 s of activity interrupted by 30 s of rest for a total of 20 min/day, five days a week.</p> <p>Results</p> <p>At 28 days, the alloxan animals displayed higher glycemia after glucose overload than the control animals. No differences in insulinemia among the groups were detected. At 120 days, no differences in serum albumin and total protein among the groups were observed. Compared to the other groups, DNA concentrations were higher in the alloxan animals that were subjected to continuous training, whereas the DNA/protein ratio was higher in the alloxan animals that were subjected to intermittent training.</p> <p>Conclusion</p> <p>It was concluded that continuous and intermittent training sessions were effective in altering muscle growth by hyperplasia and hypertrophy, respectively, in alloxan-administered animals.</p
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