bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel compressive sensing image encryption using the dynamics of an adjustable gradient Hopfield neural network
Authors: Isaac Sami Doubla , Njitacke Zeric Tabekoueng , Tsafack Nestor , Tchapga Christian Tchito , Kengne Jacques 
Published: February 2022

AbstractIn this contribution, the nonlinear dynamics of a non-autonomous model of two neurons based on the Hopfield neural network is considered. Using activation gradients as bifurcation control parameters, the properties of the model include dissipation with the existence of attractors and equilibrium points with their stability. Using traditional nonlinear analysis tools such as bifurcation diagrams, the graph of the maximum Lyapunov exponent, phase portraits, two-parameter diagrams, and attraction basins, the complex behaviour of the two-dimensional Hopfield neural network has been investigated and several windows of multistability involving the coexistence of up to four coexisting attractors have been found. Besides, the results of our numerical simulation of the multistability have been further supported using some Pspice simulation. The effect of the fractional-order derivative is also explored, and it is found that the route toward chaos is completely different when the order q of the HNN is varied between $$0<q<1$$

0
<
q
<
1

. Finally, a compressive sensing approach is used to compress and encrypt color images based on the sequences of the above-mentioned system. The plain color image is decomposed into Red, Green, and Blue components. The Discrete Wavelet Transform (DWT) is applied to each component to obtain the corresponding sparse components. Confusion keys are obtained from the proposed chaotic system to scramble each sparse component. The measurement matrices obtained from the chaotic sequence are used to compress the confused sparse matrices corresponding to the Red, Green, and Blue components. Each component is quantified and a diffusion step is then applied to improve the randomness and, consequently, the information entropy. Experimental analysis of the proposed method yields a running time (t) of 6.85 ms, a maximum entropy value of 7.9996 for global and 7.9153 for local, an encryption throughput (ET) value of 114.80, and a number of cycles (NC) of 20.90. Analysis of these metrics indicates that the proposed scheme is competitive with some recent literature.
Level-Crossing Sampling with Multiple Temporal Resolutions for Speech Signals
Authors: Premanand B. , Sheeba V. S. 
Published: February 2022

Level-crossing sampling (LCS) is an alternative to the uniform sampling method and is suitable for sparse and bursty signals. LCS, which is adaptive to amplitude variations of the signals, mainly focuses on reducing the total number of samples. Presently, speech signals are sampled with LCS methods that have a constant temporal resolution, and they require time-to-digital converters (TDC) with a wide dynamic range. A long sequence of overflow counts of the TDC counter may be generated during silence regions if the dynamic range is reduced. This paper proposes level-crossing samplers with multiple temporal resolutions for speech signals. Frequency scaling is applied to standard LCS, adaptive LCS and peak sampling. During the silence region, the frequency of the TDC clock is scaled down, which enables the representation of longer intervals with smaller words. The number of bits per sample and hence the total number of samples generated are decreased due to the reduction in the dynamic range of the TDC. Simulation results indicate that the proposed method outperforms the conventional level-crossing samplers, which do not employ frequency scaling. In addition to a significant reduction in data size, this method can also be used for real-time automatic detection of silence regions in a speech signal.
Reinforcement Routing on Proximity Graph for Efficient Recommendation
Authors: Feng Chao , Lian Defu , Wang Xiting , Liu Zheng , Xie Xing , Chen Enhong 
Published: February 2022

We focus on Maximum Inner Product Search (MIPS), which is an essential problem in many machine learning communities. Given a query, MIPS finds the most similar items with the maximum inner products. Methods for Nearest Neighbor Search (NNS) which is usually defined on metric space do not exhibit the satisfactory performance for MIPS problem since inner product is a non-metric function. However, inner products exhibit many good properties compared with metric functions, such as avoiding vanishing and exploding gradients. As a result, inner product is widely used in many recommendation systems, which makes efficient Maximum Inner Product Search a key for speeding up many recommendation systems.
Graph-based methods for NNS problem show the superiorities compared with other class methods. Each data point of the database is mapped to a node of the proximity graph. Nearest neighbor search in the database can be converted to route on the proximity graph to find the nearest neighbor for the query. This technique can be used to solve MIPS problem. Instead of searching the nearest neighbor for the query, we search the item with a maximum inner product with query on the proximity graph. In this article, we propose a reinforcement model to train an agent to search on the proximity graph automatically for MIPS problem if we lack the ground truths of training queries. If we know the ground truths of some training queries, our model can also utilize these ground truths by imitation learning to improve the agent’s searchability. By experiments, we can see that our proposed mode which combines reinforcement learning with imitation learning shows the superiorities over the state-of-the-art methods.
Targeting the Ubiquitin–Proteasome System Using the UBA1 Inhibitor TAK-243 is a Potential Therapeutic Strategy for Small-Cell Lung Cancer
Authors: Majeed Safa , Aparnathi Mansi K. , Nixon Kevin C.J. , Venkatasubramanian Vidhyasagar , Rahman Fariha , Song Lifang , Weiss Jessica , Barayan Ranya , Sugumar Vijithan , Barghout Samir H. , Pearson Joel D. , Bremner Rod , Schimmer Aaron D. , Tsao Ming S. , Liu Geoffrey , Lok Benjamin H. 
Published: February 2022

Abstract

Purpose:
Small cell lung cancer (SCLC) is an aggressive disease with an overall 5-year survival rate of less than 10%. Treatment for SCLC with cisplatin/etoposide chemotherapy (C/E) ± radiotherapy has changed modestly over several decades. The ubiquitin-proteasome system is an underexplored therapeutic target for SCLC. We preclinically evaluated TAK-243, a first-in-class small molecule E1 inhibitor against UBA1.

Experimental Design:
We assessed TAK-243 in 26 SCLC cell-lines as monotherapy and combined with C/E, the PARP-inhibitor, olaparib, and with radiation using cell viability assays. We interrogated TAK-243 response with gene expression to identify candidate biomarkers. We evaluated TAK-243 alone and in combination with olaparib or radiotherapy with SCLC patient-derived xenografts (PDX).

Results:
Most SCLC cell lines were sensitive to TAK-243 monotherapy (EC50 median 15.8 nmol/L; range 10.2 nmol/L–367.3 nmol/L). TAK-243 sensitivity was associated with gene-sets involving the cell cycle, DNA and chromatin organization, and DNA damage repair, while resistance associated with cellular respiration, translation, and neurodevelopment. These associations were also observed in SCLC PDXs. TAK-243 synergized with C/E and olaparib in vitro across sensitive and resistant SCLC cell lines. Considerable TAK-243–olaparib synergy was observed in an SCLC PDX resistant to both drugs individually. TAK-243 radiosensitization was also observed in an SCLC PDX.

Conclusions:
TAK-243 displays efficacy in SCLC preclinical models. Enrichment of gene sets is associated with TAK-243 sensitivity and resistance. TAK-243 exhibits synergy when combined with genotoxic therapies in cell lines and PDXs. TAK-243 is a potential therapeutic strategy to improve SCLC patient outcomes, both as a single agent and in combination with existing therapies.
Tumor Drug Concentration and Phosphoproteomic Profiles After Two Weeks of Treatment With Sunitinib in Patients with Newly Diagnosed Glioblastoma
Authors: van Linde Myra E. , Labots Mariette , Brahm Cyrillo G. , Hovinga Koos E. , De Witt Hamer Philip C. , Honeywell Richard J. , de Goeij-de Haas Richard , Henneman Alex A. , Knol Jaco C. , Peters Godefridus J. , Dekker Henk , Piersma Sander R. , Pham Thang V. , Vandertop William P. , Jiménez Connie R. , Verheul Henk M.W. 
Published: February 2022

Abstract

Purpose:
Tyrosine kinase inhibitors (TKI) have poor efficacy in patients with glioblastoma (GBM). Here, we studied whether this is predominantly due to restricted blood–brain barrier penetration or more to biological characteristics of GBM.

Patients and Methods:
Tumor drug concentrations of the TKI sunitinib after 2 weeks of preoperative treatment was determined in 5 patients with GBM and compared with its in vitro inhibitory concentration (IC50) in GBM cell lines. In addition, phosphotyrosine (pTyr)-directed mass spectrometry (MS)-based proteomics was performed to evaluate sunitinib-treated versus control GBM tumors.

Results:
The median tumor sunitinib concentration of 1.9 μmol/L (range 1.0–3.4) was 10-fold higher than in concurrent plasma, but three times lower than sunitinib IC50s in GBM cell lines (median 5.4 μmol/L, 3.0–8.5; P = 0.01). pTyr-phosphoproteomic profiles of tumor samples from 4 sunitinib-treated versus 7 control patients revealed 108 significantly up- and 23 downregulated (P &lt; 0.05) phosphopeptides for sunitinib treatment, resulting in an EGFR-centered signaling network. Outlier analysis of kinase activities as a potential strategy to identify drug targets in individual tumors identified nine kinases, including MAPK10 and INSR/IGF1R.

Conclusions:
Achieved tumor sunitinib concentrations in patients with GBM are higher than in plasma, but lower than reported for other tumor types and insufficient to significantly inhibit tumor cell growth in vitro. Therefore, alternative TKI dosing to increase intratumoral sunitinib concentrations might improve clinical benefit for patients with GBM. In parallel, a complex profile of kinase activity in GBM was found, supporting the potential of (phospho)proteomic analysis for the identification of targets for (combination) treatment.
Neck Circumference and Risk of Incident Atrial Fibrillation in the Framingham Heart Study
Authors: Kornej Jelena , Lin Honghuang , Trinquart Ludovic , Jackson Corban R. , Ko Darae , Benjamin Emelia J. , Preis Sarah R. 
Published: February 2022

Background
Increased neck circumference, a proxy for upper‐body subcutaneous fat, is associated with cardiovascular risk and metabolic risk factors, accounting for body mass index (BMI) and waist circumference. The association between neck circumference and incident atrial fibrillation (AF) is unclear. The aim of current study was to evaluate the association between neck circumference and incident AF.

Methods and Results

We selected participants from the Framingham Heart Study aged ≥55 years without diagnosed AF and with available neck circumference, BMI, and waist circumference measurements. We defined high neck circumference as ≥14 inches in women and ≥17 inches in men on the basis of the Contal and O’Quigley changepoint method. We used Fine‐Gray models to estimate subdistribution hazards ratios (sHRs) for the association between neck circumference and incident AF accounting for the competing risk of death. We adjusted models for clinical risk factors. We then additionally adjusted separately for BMI, waist circumference, and height/weight. The study sample included 4093 participants (mean age 64±7 years, 55% female). During 11.2±5.7 mean years of follow‐up, incident AF occurred in 571 participants. High neck circumference was associated with incident AF (sHR for high versus low: 1.58; 95% CI, 1.32–1.90,
P
<0.0001). The association remained significant after adjustment for BMI (sHR, 1.51; 95% CI, 1.21–1.89;
P
=0.0003), waist circumference (sHR, 1.47; 95% CI, 1.18–1.83;
P
<0.0001), and height/weight (sHR, 1.37; 95% CI, 1.09–1.72;
P
=0.007).

Conclusions
High neck circumference was associated with incident AF adjusting for traditional adiposity measures such as BMI and waist circumference.
Seasonal Variation of Atrial Fibrillation Admission and Quality of Care in the United States
Authors: Sheehy Shanshan , Fonarow Gregg C. , Holmes DaJuanicia N. , Lewis William R. , Matsouaka Roland A. , Piccini Jonathan P. , Zhi Lillian , Bhatt Deepak L. 
Published: February 2022

Background
Currently, little is known regarding seasonal variation for atrial fibrillation (AF) in the United States and whether quality of care for AF varies between seasons.

Methods and Results
The GWTG‐AFib (Get With The Guidelines–AFib) registry was initiated by the American Heart Association to enhance national guideline adherence for treatment and management of AF. Our analyses included 61 291 patients who were admitted at 141 participating hospitals from 2014 to 2018 across the United States. Outcomes included numbers of AF admissions and quality‐of‐care measures (defect‐free care, defined as a patient’s receiving all eligible measures). For quality‐of‐care measures, generalized estimating equations accounting for within‐site correlations were used to estimate odds ratios (ORs) with 95% CIs, adjusting patient and hospital characteristics. The proportion of AF admissions for each season was similar, with the highest percentage of AF admissions being observed in the fall (spring 25%, summer 25%, fall 27%, and winter 24%). Overall, AF admissions across seasons were similar, with no seasonal variation observed. No seasonal variation was observed for incident AF. There were no seasonal differences in care quality (multivariable adjusted ORs and 95% CIs were 0.93 (0.87–1.00) for winter, 1.09 (1.01–1.18) for summer, and 1.08 (0.97–1.20) for fall, compared with spring).

Conclusions
In a nationwide quality improvement registry, no seasonal variation was observed in hospital admissions for AF or quality of care for AF.
Transitions of Care Among Patients Undergoing Percutaneous Coronary Intervention for Stable Angina: Insights From the Veterans Affairs Clinical Assessment Reporting and Tracking Program
Authors: Waldo Stephen W. , Glorioso Thomas J. , Barón Anna E. , Doll Jacob A. , Plomondon Mary E. , Ho P. Michael 
Published: February 2022

Background
Effective transitions from the procedural to outpatient setting are essential to ensure high‐quality cardiovascular care across health care systems, particularly among patients undergoing invasive cardiac procedures. We evaluated the association of postprocedural follow‐up visits and antiplatelet prescriptions with clinical outcomes among patients undergoing percutaneous coronary intervention for stable angina at community or Veterans Affairs (VA) hospitals.

Methods and Results
Patients who actively received care within the VA Healthcare System and underwent percutaneous coronary intervention for stable angina at a community or VA hospital between October 1, 2015, and September 30, 2019, were identified. We compared mortality for patients receiving community or VA care, and among subgroups of community‐treated patients by the presence of a postprocedural follow‐up visit within 30 days or prescription for antiplatelet (P2Y12) medication within 120 days of the procedure. Among 12 837 patients who survived the first 30 days, 5133 were treated at community hospitals, and 7704 were treated in the VA. Prescriptions for antiplatelet therapy were less common for those treated in the community (85%) compared with the VA at 1 year (95%; hazard ratio [HR], 0.46; 95% CI, 0.44–47). Compared with VA‐treated patients, the hazards for death were similar for patients treated in the community with a follow‐up visit (HR, 1.17; 95% CI, 0.97–1.40) or with a fill for an antiplatelet therapy (HR, 1.08; 95% CI, 0.90–1.30). However, patients treated in the community without a follow‐up visit had an 86% (HR, 1.86; 95% CI, 1.40–2.48) increased hazard of death, and those without antiplatelet prescription fill had a 144% increased hazard of death (HR, 2.44; 95% CI, 1.85–3.21) compared with all VA‐treated patients.

Conclusions
Patients treated at community facilities have a decreased chance of receiving antiplatelet prescriptions after percutaneous coronary intervention with a concordant increased hazard of mortality, emphasizing the importance of transitions of care across health care systems when assessing cardiovascular quality.
Christian-Buddhist Intercommunication of Late Antiquity
Authors: Schumann Andrew 
Published: February 2022

Abstract
The paper is devoted to a historical reconstruction of cultural and commercial contacts which took place between Egypt and India at the peak of the maritime Silk Road to the West in antiquity, i.e. from the first to the fifth century AD, and to how these contacts were reflected by the Roman authors of that time. It is shown that in this context the story of Siddhārtha Gautama can have been transmitted to the West from the first to the fifth century AD. This study is based on the world-systems approach to late antiquity and it has the following two complementary dimensions: (i) reconstructing archeological evidences for the contacts of that time; (ii) cross-cultural textual analysis. As a result, it was detected that almost all the main claims of late antique authors about Buddhism and the ways of its expansion are well confirmed by archeology.
Temporal Greenness Trends in Stable Natural Land Cover and Relationships with Climatic Variability across the Conterminous United States
Authors: Ji Lei , Brown Jesslyn F. 
Published: February 2022

Abstract
Assessment of temporal trends in vegetation greenness and related influences aids understanding of recent changes in terrestrial ecosystems and feedbacks from weather, climate, and environment. We analyzed 1-km normalized difference vegetation index (NDVI) time series data (1989–2016) derived from the Advanced Very High Resolution Radiometer (AVHRR) and developed growing-season time-integrated NDVI (GS-TIN) for estimating seasonal vegetation activity across stable natural land cover in the conterminous United States (CONUS). After removing areas from analysis that had experienced land-cover conversion or modification, we conducted a monotonic trend analysis on the GS-TIN time series and found that significant positive temporal trends occurred over 35% of the area, whereas significant negative trends were observed over only 3.5%. Positive trends were prevalent in the forested lands of the eastern one-third of CONUS and far northwest, as well as in grasslands in the north-central plains. We observed negative and nonsignificant trends mainly in the shrublands and grasslands across the northwest, southwest, and west-central plains. To understand the relationship of climate variability with these temporal trends, we conducted partial and multiple correlation analyses on GS-TIN, growing-season temperature, and water-year precipitation time series. The GS-TIN trends in northern forests were positively correlated with temperature. The GS-TIN trends in the central and western shrublands and grasslands were negatively correlated with temperature and positively correlated with precipitation. Our results revealed spatial patterns in vegetation greenness trends for different stable natural vegetation types across CONUS, enhancing understanding gained from prior studies that were based on coarser 8-km AVHRR data.

Significance Statement
Assessing vegetation trends, cycles, and related influences is important for understanding the responses and feedbacks of terrestrial ecosystems to climatic and environmental changes. We analyzed vegetation greenness trends (1989–2016) for stable natural land cover across the conterminous United States, based on vegetation index time series derived from coarse-resolution optical satellite sensors. We found greening trends in the forests of the east and far northwest and the grasslands of the northern central plains that correlated with increasing temperature in the regions. We observed browning and no trends mainly in the shrublands and grasslands across the northwest, southwest, and western central plains, associated with increasing temperature and decreasing precipitation. Future research should focus on vegetation greenness analysis using finer-resolution satellite data.
A Variational Method for Analyzing Vortex Flows in Radar-Scanned Tornadic Mesocyclones. Part III: Sensitivities to Vortex Center Location Errors
Authors: Xu Qin , Wei Li 
Published: February 2022

Abstract
When the vortex center location is estimated from a radar-scanned tornadic mesocyclone, the estimated location is not error-free. This raises an important issue concerning the sensitivities of analyzed vortex flow (VF) fields by the VF-Var (formulated in Part I of this paper series and tested in Part II) to vortex center location errors, denoted by Δxc. Numerical experiments are performed to address this issue with the following findings: The increase of |Δxc| from zero to a half of vortex core radius causes large analysis error increases in the vortex core but the increased analysis errors decrease rapidly away from the vortex core especially for dual-Doppler analyses. The increased horizontal-velocity errors in the vortex core are mainly in the Δxc-normal component, because this component varies much more rapidly than the other component along the Δxc direction in the vortex core. The vertical variations of Δxc distort the vertical correlation structure of Δxc-dislocated VF-dependent background error covariance, which can increase the analysis errors in the vortex core. The dual-Doppler analyses have adequate accuracies outside the vortex core even when |Δxc| increases to a half of vortex core radius, while single-Doppler analyses can also have adequate accuracies outside the vortex core mainly for the single-Doppler-observed velocity component. The sensitivities to Δxc are largely unaffected by the vortex slanting. The above findings are important and useful for assessing the accuracies of analyzed VFs for real radar-observed tornadic mesocyclones.

Significance Statement
When the vortex center location is estimated from a radar-scanned tornadic mesocyclone, the estimated location is not error-free. This raises an issue concerning the sensitivity of analyzed vortex flow (VF) by the VF-Var (formulated in Part I of this paper series and tested with simulated radar observations in Part II) to vortex center location error. This issue and its required investigations are very important for the VF-Var to be applied to real radar-observed tornadic mesocyclones, especially in an operational setting with the WSR-88Ds. Numerical experiments are performed to address this issue. The findings from these experiments are important and useful for assessing the accuracies of VF-Var analyzed VF fields for real radar-observed tornadic mesocyclones.