240 research outputs found
The customer choice model of commercial retailers based on MarKov analysis
The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity
Enhancement of brain-type creatine kinase activity ameliorates neuronal deficits in Huntington's disease
AbstractHuntington's disease (HD) is a hereditary neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin (HTT) gene. Brain-type creatine kinase (CKB) is an enzyme involved in energy homeostasis via the phosphocreatine–creatine kinase system. Although downregulation of CKB was previously reported in brains of HD mouse models and patients, such regulation and its functional consequence in HD are not fully understood. In the present study, we demonstrated that levels of CKB found in both the soma and processes were markedly reduced in primary neurons and brains of HD mice. We show for the first time that mutant HTT (mHTT) suppressed the activity of the promoter of the CKB gene, which contributes to the lowered CKB expression in HD. Exogenous expression of wild-type CKB, but not a dominant negative CKB mutant, rescued the ATP depletion, aggregate formation, impaired proteasome activity, and shortened neurites induced by mHTT. These findings suggest that negative regulation of CKB by mHTT is a key event in the pathogenesis of HD and contributes to the neuronal dysfunction associated with HD. In addition, besides dietary supplementation with the CKB substrate, strategies aimed at increasing CKB expression might lead to the development of therapeutic treatments for HD
Multistep Hybrid Iterations for Systems of Generalized Equilibria with Constraints of Several Problems
We first introduce and analyze one multistep iterative algorithm by hybrid shrinking projection method for finding a solution of the system of generalized equilibria with constraints of several problems: the generalized mixed equilibrium problem, finitely many variational inclusions, the minimization problem for a convex and continuously Fréchet differentiable functional, and the fixed-point problem of an asymptotically strict pseudocontractive mapping in the intermediate sense in a real Hilbert space. We prove strong convergence theorem for the iterative algorithm under suitable conditions. On the other hand, we also propose another multistep iterative algorithm involving no shrinking projection method and derive its weak convergence under mild assumptions
Triple Hierarchical Variational Inequalities with Constraints of Mixed Equilibria, Variational Inequalities, Convex Minimization, and Hierarchical Fixed Point Problems
We introduce and analyze a hybrid iterative algorithm by virtue of Korpelevich's extragradient method, viscosity approximation method, hybrid steepest-descent method, and averaged mapping approach to the gradient-projection algorithm. It is proven that under appropriate assumptions, the proposed algorithm converges strongly to a common element of the fixed point set of infinitely many nonexpansive mappings, the solution set of finitely many generalized mixed equilibrium problems (GMEPs), the solution set of finitely many variational inequality problems (VIPs), the solution set of general system of variational inequalities (GSVI), and the set of minimizers of convex minimization problem (CMP), which is just a unique solution of a triple hierarchical variational inequality (THVI) in a real Hilbert space. In addition, we also consider the application of the proposed algorithm to solve a hierarchical fixed point problem with constraints of finitely many GMEPs, finitely many VIPs, GSVI, and CMP. The results obtained in this paper improve and extend the corresponding results announced by many others
Strong and Weak Convergence Criteria of Composite Iterative Algorithms for Systems of Generalized Equilibria
We first introduce and analyze one iterative algorithm by using the composite shrinking projection method for finding a solution of the system of generalized equilibria with constraints of several problems: a generalized mixed equilibrium problem, finitely many variational inequalities, and the common fixed point problem of an asymptotically strict pseudocontractive mapping in the intermediate sense and infinitely many nonexpansive mappings in a real Hilbert space. We prove a strong convergence theorem for the iterative algorithm under suitable conditions. On the other hand, we also propose another iterative algorithm involving no shrinking projection method and derive its weak convergence under mild assumptions. Our results improve and extend the corresponding results in the earlier and recent literature
Eff ect of a comprehensive programme to provide universal access to care for sputum-smear-positive multidrugresistant tuberculosis in China: a before-and-after study
Background China has a quarter of all patients with multidrug-resistant tuberculosis (MDRTB) worldwide, but less
than 5% are in quality treatment programmes. In a before-and-after study we aimed to assess the eff ect of a
comprehensive programme to provide universal access to diagnosis, treatment, and follow-up for MDRTB in
four Chinese cities (population 18 million).
Methods We designated city-level hospitals in each city to diagnose and treat MDRTB. All patients with smear-positive
pulmonary tuberculosis diagnosed in Center for Disease Control (CDC) clinics and hospitals were tested for MDRTB
with molecular and conventional drug susceptibility tests. Patients were treated with a 24 month treatment package
for MDRTB based on WHO guidelines. Outpatients were referred to the CDC for directly observed therapy.
We capped total treatment package cost at US796 to $174), reducing the ratio of patients’ expenses
to annual household income from 17·6% to 3·5% (p<0·0001 for all comparisons between baseline and programme
periods). However, 36 (15%) patients did not start or had to discontinue treatment in the programme period because
of fi nancial diffi culties.
Interpretation This comprehensive programme substantially increased access to diagnosis, quality treatment, and
aff ordable treatment for MDRTB. The programme could help China to achieve universal access to MDRTB care but
greater fi nancial risk protection for patients is needed
How to Report and Benchmark Emerging Field-Effect Transistors
Emerging low-dimensional nanomaterials have been studied for decades in
device applications as field-effect transistors (FETs). However, properly
reporting and comparing device performance has been challenging due to the
involvement and interlinking of multiple device parameters. More importantly,
the interdisciplinarity of this research community results in a lack of
consistent reporting and benchmarking guidelines. Here we report a consensus
among the authors regarding guidelines for reporting and benchmarking important
FET parameters and performance metrics. We provide an example of this reporting
and benchmarking process for a two-dimensional (2D) semiconductor FET. Our
consensus will help promote an improved approach for assessing device
performance in emerging FETs, thus aiding the field to progress more
consistently and meaningfully.Comment: 15 pages, 3 figures, Under review at Nature Electronic
A QoS-Guaranteed Coverage Precedence Routing Algorithm for Wireless Sensor Networks
For mission-critical applications of wireless sensor networks (WSNs) involving extensive battlefield surveillance, medical healthcare, etc., it is crucial to have low-power, new protocols, methodologies and structures for transferring data and information in a network with full sensing coverage capability for an extended working period. The upmost mission is to ensure that the network is fully functional providing reliable transmission of the sensed data without the risk of data loss. WSNs have been applied to various types of mission-critical applications. Coverage preservation is one of the most essential functions to guarantee quality of service (QoS) in WSNs. However, a tradeoff exists between sensing coverage and network lifetime due to the limited energy supplies of sensor nodes. In this study, we propose a routing protocol to accommodate both energy-balance and coverage-preservation for sensor nodes in WSNs. The energy consumption for radio transmissions and the residual energy over the network are taken into account when the proposed protocol determines an energy-efficient route for a packet. The simulation results demonstrate that the proposed protocol is able to increase the duration of the on-duty network and provide up to 98.3% and 85.7% of extra service time with 100% sensing coverage ratio comparing with LEACH and the LEACH-Coverage-U protocols, respectively
Bone-targeting agents in major solid tumour metastases: a multinational cohort study
OBJECTIVE:
To describe the epidemiology, clinical characteristics and utilisation patterns of bone-targeting agents (BTAs) in patients with bone metastases from breast, prostate and lung cancer.
METHODS:
This is a multinational retrospective cohort study including patients with three major solid tumours (breast, prostate and lung cancer) and newly initiated on BTAs (ie, denosumab, zoledronic acid and pamidronate). Records were retrieved from nationwide health databases from Hong Kong and Taiwan (HK and TW: 2013–2017) and Korea (KR: 2012–2016). Descriptive analyses included the annual incidence rates of bone metastases and the cumulative incidence curves of BTA initiation. We used Sankey diagrams to visualise the dynamic BTA utilisation patterns.
RESULTS:
The annual incidence rate of bone metastases ranged from 3.5% to 4.5% in TW, from 9.6% to 10.3% in HK and from 2.9% to 3.8% in KR. We identified 14.1% (5127), 9.3% (883) and 9.4% (4800) of patients with bone metastases newly initiated on BTAs in TW, HK and KR, respectively. The most frequently used BTA in TW (67.1%) and HK (51.9%) was denosumab, while in KR (84.8%) it was zoledronic acid. Sankey diagrams indicated the proportion of patients remaining on denosumab was highest in TW and HK, while it was zoledronic acid in KR. Specifically, in TW, patients who were on bisphosphonates or had discontinued treatment frequently switched to or reinitiated denosumab.
CONCLUSIONS:
We found the rate of BTA utilisation remained low across all sites and tumour types in recent years. The dynamic utilisation patterns of BTAs provide better understanding of the treatment landscape for future evaluation of associated outcomes of patients
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