5,225 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%)
"It's Huge, in a Way." Conflicting Stakeholder Priorities for Managing Hearing Impairment for People Living with Dementia in Residential Aged Care Facilities
Objectives:
The aims of this study were to a) explore the impact of hearing impairment on people living with dementia in residential aged care facilities (RACFs) and b) investigate management of hearing impairment for this population. /
Methods:
A descriptive qualitative approach, consisting of semi-structured interviews, was conducted with 23 participants across four stakeholder groups (audiologists, care staff, family members and individuals with dementia and hearing impairment living in RACFs). /
Results:
Thematic analysis revealed an overarching theme of âdifferent priorities for managing hearing impairmentâ that emerged from the data. Audiologists and care staff prioritized different practices for managing hearing impairment: audiologists emphasized hearing aids and care staff emphasized communication strategies. Care staff also identified that current management of hearing impairment was sub-optimal as they do not prioritize managing it. /
Conclusions:
Residents with dementia and hearing impairment living in RACFs are not receiving optimal hearing management. Further research is required to understand the factors that influence this
Compositional Inversion Symmetry Breaking in Ferroelectric Perovskites
Ternary cubic perovskite compounds of the form A_(1/3)A'_(1/3)A''_(1/3)BO_3
and AB_(1/3)B'_(1/3)B''_(1/3)O_3, in which the differentiated cations form an
alternating series of monolayers, are studied using first-principles methods.
Such compounds are representative of a possible new class of materials in which
ferroelectricity is perturbed by compositional breaking of inversion symmetry.
For isovalent substitution on either sublattice, the ferroelectric double-well
potential is found to persist, but becomes sufficiently asymmetric that
minority domains may no longer survive. The strength of the symmetry breaking
is enormously stronger for heterovalent substitution, so that the double-well
behavior is completely destroyed. Possible means of tuning between these
behaviors may allow for the optimization of resulting materials properties.Comment: 4 pages, two-column style with 3 postscript figures embedded. Uses
REVTEX and epsf macros. Also available at
http://www.physics.rutgers.edu/~dhv/preprints/index.html#sai_is
Testing the paradox of enrichment along a land use gradient in a multitrophic aboveground and belowground community
In the light of ongoing land use changes, it is important to understand how multitrophic communities perform at different land use intensities. The paradox of enrichment predicts that fertilization leads to destabilization and extinction of predator-prey systems. We tested this prediction for a land use intensity gradient from natural to highly fertilized agricultural ecosystems. We included multiple aboveground and belowground trophic levels and land use-dependent searching efficiencies of insects. To overcome logistic constraints of field experiments, we used a successfully validated simulation model to investigate plant responses to removal of herbivores and their enemies. Consistent with our predictions, instability measured by herbivore-induced plant mortality increased with increasing land use intensity. Simultaneously, the balance between herbivores and natural enemies turned increasingly towards herbivore dominance and natural enemy failure. Under natural conditions, there were more frequently significant effects of belowground herbivores and their natural enemies on plant performance, whereas there were more aboveground effects in agroecosystems. This result was partly due to the âboom-bustâ behavior of the shoot herbivore population. Plant responses to herbivore or natural enemy removal were much more abrupt than the imposed smooth land use intensity gradient. This may be due to the presence of multiple trophic levels aboveground and belowground. Our model suggests that destabilization and extinction are more likely to occur in agroecosystems than in natural communities, but the shape of the relationship is nonlinear under the influence of multiple trophic interactions.
Unlocking the Metalation Applications of TMPâpowered Fe and Co(II) bis(amides): Synthesis, Structure and Mechanistic Insights
ProducciĂłn CientĂficaTypified by LiTMP and TMPMgCl.LiCl, (TMP=2,2,6,6-tetramethylpiperidide), s-block metal amides have found widespread applications in arene deprotonative metalation. On the contrary, transition metal amides lack sufficient basicity to activate these substrates. Breaking new ground in this field, here we present the synthesis and full characterisation of earth-abundant transition metals M(TMP)2 (M=Fe, Co). Uncovering a new reactivity profile towards fluoroarenes, these amide complexes can promote direct MâH exchange processes regioselectively using one or two of their basic amide arms. Remarkably, even when using a perfluorinated substrate, selective C-H metalation occurs leaving CâF bonds intact. Their kinetic basicity can be boosted by LiCl or NBu4Cl additives which enables formation of kinetically activated ate species. Combining spectroscopic and structural studies with DFT calculations, mechanistic insights have been gained on how these low polarity metalation processes take place. M(TMP)2 can also be used to access ferrocene and cobaltocene by direct deprotonation of cyclopentadiene and undergo efficient CO2 insertion of both amide groups under mild reaction conditions.Swiss National
Science Foundation (SNF) (projects numbers 206021_
177033 and 188573), the University of Bern, the Irish
Research Council (GOIPG/2021/88, M.M.), and the University
of Valladolid (CONVREC-2021-221, M.N.P.-D.
Cognitive architectures as Lakatosian research programmes: two case studies
Cognitive architectures - task-general theories of the structure and function of the complete cognitive system - are sometimes argued to be more akin to frameworks or belief systems than scientific theories. The argument stems from the apparent non-falsifiability of existing cognitive architectures. Newell was aware of this criticism and argued that architectures should be viewed not as theories subject to Popperian falsification, but rather as Lakatosian research programs based on cumulative growth. Newell's argument is undermined because he failed to demonstrate that the development of Soar, his own candidate architecture, adhered to Lakatosian principles. This paper presents detailed case studies of the development of two cognitive architectures, Soar and ACT-R, from a Lakatosian perspective. It is demonstrated that both are broadly Lakatosian, but that in both cases there have been theoretical progressions that, according to Lakatosian criteria, are pseudo-scientific. Thus, Newell's defense of Soar as a scientific rather than pseudo-scientific theory is not supported in practice. The ACT series of architectures has fewer pseudo-scientific progressions than Soar, but it too is vulnerable to accusations of pseudo-science. From this analysis, it is argued that successive versions of theories of the human cognitive architecture must explicitly address five questions to maintain scientific credibility
Controllability and Robustness of Functional and Structural Connectomic Networks in Glioma Patients
Simple Summary
Gliomas are known to impact on large-scale networks beyond the tumor location, but it is unknown how the tumor affects controllability and robustness of neural networks. We applied advanced control theory algorithms on connectivity data of structural and functional networks of prognostically differing glioma patients and healthy controls. We determined the driver nodes of the default-mode network (DMN), which are receptive to outside signals, and critical nodes as the most important elements for network controllability. Patients showed decreased network controllability and robustness mainly in the isocitratedehydrogenase (IDH) wildtype group, while additional topological shifts of driver and critical nodes were observed mainly in the prognostically more favourable IDH mutated patients. We hereby suggest a novel approach for elucidating disease evolution in brain cancer, which may aid in defining potential treatment targets under the aspects of network controllability and robustness in glioma patients.
Abstract
Previous studies suggest that the topological properties of structural and functional neural networks in glioma patients are altered beyond the tumor location. These alterations are due to the dynamic interactions with large-scale neural circuits. Understanding and describing these interactions may be an important step towards deciphering glioma disease evolution. In this study, we analyze structural and functional brain networks in terms of determining the correlation between network robustness and topological features regarding the default-mode network (DMN), comparing prognostically differing patient groups to healthy controls. We determine the driver nodes of these networks, which are receptive to outside signals, and the critical nodes as the most important elements for controllability since their removal will dramatically affect network controllability. Our results suggest that network controllability and robustness of the DMN is decreased in glioma patients. We found losses of driver and critical nodes in patients, especially in the prognostically less favorable IDH wildtype (IDHwt) patients, which might reflect lesion-induced network disintegration. On the other hand, topological shifts of driver and critical nodes, and even increases in the number of critical nodes, were observed mainly in IDH mutated (IDHmut) patients, which might relate to varying degrees of network plasticity accompanying the chronic disease course in some of the patients, depending on tumor growth dynamics. We hereby implement a novel approach for further exploring disease evolution in brain cancer under the aspects of neural network controllability and robustness in glioma patients
Hear-Communicate-Remember: Feasibility of delivering an integrated intervention for family caregivers of people with dementia and hearing impairment via telehealth
PURPOSE: To evaluate the feasibility of Hear-Communicate-Remember, a training programme developed for family caregivers of people with dementia and hearing impairment that integrated hearing, communication and memory strategies, which was intended to be delivered via telehealth. MATERIALS AND METHODS: Participants included six dyads consisting of adults with dementia and hearing impairment and their family caregivers. Data collection involved a combination of semi-structured interviews, self-report questionnaires and field notes. RESULTS: Analysis of the qualitative interviews revealed four themes: appropriateness of intervention resources, considerations for the delivery of intervention via telehealth, knowledge and application of intervention strategies, and impact of the intervention on day-to-day life. Results from the satisfaction survey indicated that caregiver participants were mostly satisfied with all aspects of the intervention except the use of some technological components. The field notes described challenges with implementation via telehealth. CONCLUSIONS: Future research involving a cohort comparison study with a larger cohort of dyads is needed to establish treatment efficacy
The response of perennial and temporary headwater stream invertebrate communities to hydrological extremes
The headwaters of karst rivers experience considerable hydrological variability, including spates and streambed drying. Extreme summer flooding on the River Lathkill (Derbyshire, UK) provided the opportunity to examine the invertebrate community response to unseasonal spate flows, flow recession and, at temporary sites, streambed drying. Invertebrates were sampled at sites with differing flow permanence regimes during and after the spates. Following streambed drying at temporary sites, dewatered surface sediments were investigated as a refugium for aquatic invertebrates. Experimental rehydration of these dewatered sediments was conducted to promote development of desiccation-tolerant life stages. At perennial sites, spate flows reduced invertebrate abundance and diversity, whilst at temporary sites, flow reactivation facilitated rapid colonisation of the surface channel by a limited number of invertebrate taxa. Following streambed drying, 38 taxa were recorded from the dewatered and rehydrated sediments, with Oligochaeta being the most abundant taxon and Chironomidae (Diptera) the most diverse. Experimental rehydration of dewatered sediments revealed the presence of additional taxa, including Stenophylax sp. (Trichoptera: Limnephilidae) and Nemoura sp. (Plecoptera: Nemouridae). The influence of flow permanence on invertebrate community composition was apparent despite the aseasonal high-magnitude flood events
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