Miracle-dz/UniFAR-FTUs huggingface dataset:
Progressive clustering of manifold-modeled data based on tangent space variations

An important research topic of the recent years has been to understand and analyze manifold-modeled data for clustering and classification applications. Most clustering methods developed for data of non-linear and low-dimensional structure are based on local linearity assumptions. However, clustering algorithms based on locally linear representations can tolerate difficult sampling conditions only to some extent, and may fail for scarcely sampled data manifolds or at high-curvature regions. In this paper, we consider a setting where each cluster is concentrated around a manifold and propose a manifold clustering algorithm that relies on the observation that the variation of the tangent space must be consistent along curves over the same data manifold. In order to achieve robustness against challenges due to noise, manifold intersections, and high curvature, we propose a progressive clustering approach: Observing the variation of the tangent space, we first detect the non-problematic manifold regions and form pre-clusters with the data samples belonging to such reliable regions. Next, these pre-clusters are merged together to form larger clusters with respect to constraints on both the distance and the tangent space variations. Finally, the samples identified as problematic are also assigned to the computed clusters to finalize the clustering. Experiments with synthetic and real datasets show that the proposed method outperforms the manifold clustering algorithms in comparison based on Euclidean distance and sparse representations.
The Penumbra System: A Mechanical Device for the Treatment of Acute Stroke due to Thromboembolism

BACKGROUND AND PURPOSE: Data from recent reports have indicated that mechanical thrombectomy may have potential as a treatment for acute ischemic stroke. The purpose of this study was to assess the safety and performance of the Penumbra System (PS): a novel mechanical device designed to reduce clot burden in acute stroke due to large-vessel occlusive disease. MATERIALS AND METHODS: A prospective, single arm, independently monitored and core laboratory adjudicated trial enrolled subjects with an acute neurologic deficit consistent with acute stroke, presenting within 8 hours of symptom onset and an angiographically verified occlusion (Thrombolysis in Myocardial Infarction [TIMI] grade 0 or 1) of a treatable intracranial vessel. The primary end point was revascularization of the target vessel to TIMI grade 2 or 3. Secondary end points were the proportion of subjects who achieved a modified Rankin Scale (mRS) score of 2 or less or a 4-point improvement on the National Institutes of Health Stroke Scale (NIHSS) score at 30-day follow-up, as well as all-cause mortality. RESULTS: Twenty-three subjects were enrolled, and 21 target vessels were treated in 20 subjects by the PS. At baseline, mean age was 60 years, mean mRS score was 4.6, and mean NIHSS score was 21. Postprocedure, all 21 of the treated vessels (100%) were successfully revascularized by the PS to TIMI 2 or 3. At 30-day follow-up, 9 subjects (45%) had a 4-point or more NIHSS improvement or an mRS of 2 or less. The all-cause mortality rate was 45% (9 of 20), which is lower than expected in this severe stroke cohort, where 70% of the subjects at baseline had either an NIHSS score of more than 20 or a basilar occlusion. CONCLUSION: Thus, early clinical experience suggests that the PS allows revascularization in certain subjects experiencing acute ischemic stroke.
Detection of error-related negativity in complex visual stimuli: a new neuroergonomic arrow in the practitioner’s quiver

Abstract Brain processes responsible for the error-related negativity (ERN) evoked response potential (ERP) have historically been studied in highly controlled laboratory experiments through presentation of simple visual stimuli. The present work describes the first time the ERN has been evoked and successfully detected in visual search of complex stimuli. A letter flanker task and a motorcycle conspicuity task were presented to participants during electroencephalographic (EEG) recording. Direct visual inspection and subsequent statistical analysis of the resultant time-locked ERP data clearly indicated that the ERN was detectable in both groups. Further, the ERN pattern did not differ between groups. Such results show that the ERN can be successfully elicited and detected in visual search of complex static images, opening the door to applied neuroergonomic use. Harnessing the brain’s error detection system presents significant opportunities and complex challenges, and implication of such are discussed in the context of human-machine systems. Practitioner Summary: For the first time, error-related negativity (ERN) has been successfully elicited and detected in a visually complex applied search task. Brain-process-based error detection in human-machine systems presents unique challenges, but promises broad neuroergonomic applications.
Extracting Location Information from Crowd-sourced Social Network Data

With millions of users worldwide, crowd-sourced social media data provide a valuable data source for events happening around the world. More specifically, microblogs, which are social networks that enforce short text messages, have a high popularity due to their availability as a mobile application and the practicality of short messages. Estimating the location of the events detected by following posts in microblogs have been the motivation of numerous recent studies. Extracting the location information and estimating the event location is a challenging task to maintain satisfactory situation awareness, especially for emergency cases such as fire or traffic accidents. Today, Twitter is among the most popular microblogging platforms, and there are recent research efforts aimed at detection of novel events online by following the Tweets. In order to analyze events, researchers generally focus on spatio-temporal features of the posts. Temporal features denote the time and ordering of posts, whereas spatial features are useful for location extraction or estimation. In this work, we present an overview on the process for toponym recognition and location estimation from microblogs.
Impact of SAMMPRIS on the future of intracranial atherosclerotic disease management: polling results from the ICAD symposium at the International Stroke Conference

Objective There are few data regarding the effect of the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial results on the management of intracranial atherosclerotic disease (ICAD). We sought to understand the impact of the SAMMPRIS trial on current ICAD clinical practices and future trial design. Methods During the ICAD symposium at the 2012 International Stroke Conference, electronic data were collected regarding attendees’ clinical management of ICAD and opinions on the feasibility of future trials post-SAMMPRIS. Results 217 attendees from different specialties, including neurologists (57%), neurointerventionalists (9%) and neurosurgeons (5%), participated in the session. The majority of respondents (77%) indicated that the results of SAMMPRIS have impacted their consideration for intracranial stenting. Post-SAMMPRIS, 84% selected ‘SAMMPRIS-style’ medical management for the treatment of ICAD. For patients with ICAD who failed aggressive medical therapy, 82% would consider an alternative approach to continuing medical therapy (30% considered clinical trial enrollment, 28% suggested angioplasty and stenting and 24% angioplasty). The majority of participants (85%) were willing to randomize patients with symptomatic ICAD in future trials. For the next ICAD trial, 29% indicated that angioplasty alone should be compared with aggressive medical therapy. Conclusions Our polling results suggest that the SAMMPRIS trial has had an impact on the current treatment of ICAD. Treatment of patients who failed medical therapy varied widely from aggressive medical therapy to balloon angioplasty, stenting or enrollment in future clinical trials. The willingness to continue clinical trials and randomize patients supports the need for future ICAD studies.
Glacial integrative modelling

Understanding the mechanisms of past climate changes requires modelling of the complex interaction between all major components of the Earth system: atmosphere, ocean, cryosphere, lithosphere and biosphere. This paper reviews attempts at such an integrative approach to modelling climate changes during the glacial age. In particular, the roles of different factors in shaping glacial climate are compared based on the results of simulations with an Earth–system model of intermediate complexity, CLIMBER–2. It is shown that ice sheets, changes in atmospheric compositions, vegetation cover, and reorganization of the ocean thermohaline circulation play important roles in glacial climate changes. Another example of this approach is the modelling of two major types of abrupt glacial climate changes: Dansgaard–Oeschger and Heinrich events. Our results corroborate some of the early proposed mechanisms, which relate abrupt climate changes to the internal instability of the ocean thermohaline circulation and ice sheets. At the same time, it is shown that realistic representation of the temporal evolution of the palaeoclimatic background is crucial to simulate observed features of the glacial abrupt climate changes.
Lack of hepcidin gene expression and severe tissue iron overload in upstream stimulatory factor 2 (USF2) knockout mice

We previously reported the disruption of the murine gene encoding the transcription factor USF2 and its consequences on glucose-dependent gene regulation in the liver. We report here a peculiar phenotype of Usf2−/− mice that progressively develop multivisceral iron overload; plasma iron overcomes transferrin binding capacity, and nontransferrin-bound iron accumulates in various tissues including pancreas and heart. In contrast, the splenic iron content is strikingly lower in knockout animals than in controls. To identify genes that may account for the abnormalities of iron homeostasis in Usf2−/− mice, we used suppressive subtractive hybridization between livers from Usf2−/− and wild-type mice. We isolated a cDNA encoding a peptide, hepcidin (also referred to as LEAP-1, for liver-expressed antimicrobial peptide), that was very recently purified from human blood ultrafiltrate and from urine as a disulfide-bonded peptide exhibiting antimicrobial activity. Accumulation of iron in the liver has been recently reported to up-regulate hepcidin expression, whereas our data clearly show that a complete defect in hepcidin expression is responsible for progressive tissue iron overload. The striking similarity of the alterations in iron metabolism between HFE knockout mice, a murine model of hereditary hemochromatosis, and the Usf2−/− hepcidin-deficient mice suggests that hepcidin may function in the same regulatory pathway as HFE. We propose that hepcidin acts as a signaling molecule that is required in conjunction with HFE to regulate both intestinal iron absorption and iron storage in macrophages.
The Determinants and Financial Statement Effects of IFRS Adoption in Nigeria

The chapter examines the determinants and financial statement effect s of IFRS adoption in Nigeria. It also investigate into the impact of effect of the adoption of IFRS on accounting figures and ratios in the financial statements of 50 companies quoted in the Nigerian Stock Exchange. The determinants considered include firm’s characteristics (firm size, operating cash flow, leverage, turnover, growth in turnover, profitability, liquidity and earnings quality) and corporate governance variables (board size, board independence and audit type). The data were obtained from the annual reports of companies listed in the Nigerian Stock Exchange between 2011 and 2013 and was analyzed using the ordinary least square (OLS) and logistic regression which were used to test for determinants of IFRS adoption while the independent t-test was used to examine the financial statement effects. With regard to the determinants, the empirical result indicates only profitability and earnings quality have significant but negative association with IFRS adoption. Moreover, IFRS adoption has significant effect on the return on equity.
Parallel Structure Fractional Repetitive Control for PWM Inverters

In this paper, a parallel structure fractional repetitive control (RC) scheme is proposed to improve the performance of pulsewidth-modulation (PWM) inverters in fractional cases where the sampling rate of the digital control system is not an integral multiple of the fundamental frequency. By introducing a correction factor, the new control scheme increases the control gains for all harmonics and locates poles accurately at targeted harmonic frequencies. As a result, the proposed control scheme achieves better tracking and rejection performance than conventional RC. Moreover, the parallel structure fractional repetitive controller requires less data memory. Dynamic response is also improved. The stability and convergence of this method are proved. Experimental results on a single-phase PWM inverter illustrate the advantages of this control scheme.
A Brucellosis Disease Control Strategy for the Kakheti Region of the Country of Georgia: An Agent‐Based Model

Brucellosis has been reported in livestock and humans in the country of Georgia with Brucella melitensis as the most common species causing disease. Georgia lacked sufficient data to assess effectiveness of the various potential control measures utilizing a reliable population‐based simulation model of animal‐to‐human transmission of this infection. Therefore, an agent‐based model was built using data from previous studies to evaluate the effect of an animal‐level infection control programme on human incidence and sheep flock and cattle herd prevalence of brucellosis in the Kakheti region of Georgia. This model simulated the patterns of interaction of human–animal workers, sheep flocks and cattle herds with various infection control measures and returned population‐based data. The model simulates the use of control measures needed for herd and flock prevalence to fall below 2%. As per the model output, shepherds had the greatest disease reduction as a result of the infection control programme. Cattle had the greatest influence on the incidence of human disease. Control strategies should include all susceptible animal species, sheep and cattle, identify the species of brucellosis present in the cattle population and should be conducted at the municipality level. This approach can be considered as a model to other countries and regions when assessment of control strategies is needed but data are scattered.
Tumor-infiltrating NY-ESO-1–specific CD8+ T cells are negatively regulated by LAG-3 and PD-1 in human ovarian cancer

NY-ESO-1 is a “cancer-testis” antigen frequently expressed in epithelial ovarian cancer (EOC) and is among the most immunogenic tumor antigens defined to date. In an effort to understand in vivo tolerance mechanisms, we assessed the phenotype and function of NY-ESO-1–specific CD8+ T cells derived from peripheral blood lymphocytes (PBLs), tumor-infiltrating lymphocytes (TILs), and tumor-associated lymphocytes (TALs) of EOC patients with NY-ESO-1-expressing tumors, with or without humoral immunity to NY-ESO-1. Whereas NY-ESO-1–specific CD8+ T cells were readily detectable ex vivo with tetramers in TILs and TALs of seropositive patients, they were only detectable in PBLs following in vitro stimulation. Compared with PBLs, tumor-derived NY-ESO-1–specific CD8+ T cells demonstrated impaired effector function, preferential usage of dominant T-cell receptor, and enriched coexpression of inhibitory molecules LAG-3 and PD-1. Expression of LAG-3 and PD-1 on CD8+ T cells was up-regulated by IL-10, IL-6 (cytokines found in tumor ascites), and tumor-derived antigen-presenting cells. Functionally, CD8+LAG-3+PD-1+ T cells were more impaired in IFN-γ/TNF-α production compared with LAG-3+PD-1− or LAG-3−PD-1− subsets. Dual blockade of LAG-3 and PD-1 during T-cell priming efficiently augmented proliferation and cytokine production by NY-ESO-1–specific CD8+ T cells, indicating that antitumor function of NY-ESO-1-specific CD8+ T cells could potentially be improved by therapeutic targeting of these inhibitory receptors.
Endothelin receptor B, a candidate gene from human studies at high altitude, improves cardiac tolerance to hypoxia in genetically engineered heterozygote mice

Significance Although model organisms have been used to understand the underlying basis of hypoxia and how to treat it, it has always been useful to learn from natural experiments in humans, such as in high-altitude dwellers. In this study, we demonstrate that decreased Endothelin receptor type B (EdnrB), a gene associated with altitude adaptation from our human study, improves cardiac tolerance to hypoxia. We show that heterozygote EdnrB mice maintain higher cardiac output and peripheral perfusion and better O2 delivery to vital organs, even in severe hypoxia. Furthermore, the transcriptome profile revealed three atria-specific genes, natriuretic peptide type A (Nppa), sarcolipin (Sln), and myosin light polypeptide 4 (Myl4), which were down-regulated by hypoxia and possibly have a role in improving cardiac performance during normoxia and hypoxia. To better understand human adaptation to stress, and in particular to hypoxia, we took advantage of one of nature’s experiments at high altitude (HA) and studied Ethiopians, a population that is well-adapted to HA hypoxic stress. Using whole-genome sequencing, we discovered that EDNRB (Endothelin receptor type B) is a candidate gene involved in HA adaptation. To test whether EDNRB plays a critical role in hypoxia tolerance and adaptation, we generated EdnrB knockout mice and found that when EdnrB−/+ heterozygote mice are treated with lower levels of oxygen (O2), they tolerate various levels of hypoxia (even extreme hypoxia, e.g., 5% O2) very well. For example, they maintain ejection fraction, cardiac contractility, and cardiac output in severe hypoxia. Furthermore, O2 delivery to vital organs was significantly higher and blood lactate was lower in EdnrB−/+ compared with wild type in hypoxia. Tissue hypoxia in brain, heart, and kidney was lower in EdnrB−/+ mice as well. These data demonstrate that a lower level of EDNRB significantly improves cardiac performance and tissue perfusion under various levels of hypoxia. Transcriptomic profiling of left ventricles revealed three specific genes [natriuretic peptide type A (Nppa), sarcolipin (Sln), and myosin light polypeptide 4 (Myl4)] that were oppositely expressed (q < 0.05) between EdnrB−/+ and wild type. Functions related to these gene networks were consistent with a better cardiac contractility and performance. We conclude that EDNRB plays a key role in hypoxia tolerance and that a lower level of EDNRB contributes, at least in part, to HA adaptation in humans.
Path analysis of IT application maturity

This paper studies effects of two management capabilities on IT application maturity. Data were collected from 123 companies in China. A basic regression finds that both capabilities have significant positive effects on IT application maturity as well as on dimension variables of IT application maturity. Further, a path analysis model is established to describe the intertwining relationship among two management capabilities and IT application maturity. Three hypotheses are accepted through model estimation. It is found that process management capability has a stronger positive direct effect on IT application than management institutional capability. Furthermore, process management capability has a positive indirect effect on IT application maturity through management institutional capability. The results provide companies with a practical insight: improvement through process management capability should be emphasised first, and it will lead to greater improvement of IT application maturity.
Apparatus for studying ultrasmall contacts

On-chip IC dimensions have been scaled down without a corresponding decrease in the size of off-chip interconnects, including pressure contacts. As the number of I/O lines increases, pressure contacts need to operate at low forces. The use of scanning tunneling microscope/atomic force microscope (STM/AFM) technology (treating an STM tip-sample junction either as a model for an ultrasmall contact per se, or a microscopic element of a larger contact) is investigated. A combined AFM/STM has been built to allow electrical characterization of contacts under a range of forces and tip and substrate materials. The contact force can be varied from 10/sup -6/ to 10/sup -9/ N, and contact dimensions (as determined by SEM) are approximately 100-nm in diameter. Initial results demonstrate that the reversibility of a contact depends on the hardness of the contact materials. <<ETX>>
Association between cerebrospinal fluid levels of asymmetric dimethyl-L-arginine, an endogenous inhibitor of endothelial nitric oxide synthase, and cerebral vasospasm in a primate model of subarachnoid hemorrhage.

OBJECT Decreased availability of nitric oxide (NO) has been proposed to evoke delayed cerebral vasospasm after sub-arachnoid hemorrhage (SAH). Asymmetric dimethyl-L-arginine (ADMA) inhibits endothelial NO synthase (eNOS) and, therefore, may be responsible for decreased NO availability in cases of cerebral vasospasm. The goal of this study was to determine whether ADMA levels are associated with cerebral vasospasm in a primate model of SAH. METHODS Twenty-two cynomolgus monkeys (six control animals and 16 with SAH) were used in this study. The levels of ADMA, L-arginine, L-citrulline, nitrites, and nitrates in cerebrospinal fluid (CSF) and serum were determined on Days 0, 7, 14, and 21 following onset of SAH. Cerebral arteriography was performed to assess the degree of vasospasm. Western blot analyses of the right and left middle cerebral arteries (MCAs) were performed to assess the expression of eNOS, type I protein-arginine methyl transferase (PRMT1) and dimethylarginine dimethylaminohydrolase (DDAH2). Cerebrospinal fluid levels of ADMA remained unchanged in the control group (six animals) and in animals with SAH that did not have vasospasm (five animals; p = 0.17), but the levels increased in animals with vasospasm (11 animals) on Day 7 post-SAH (p < 0.01) and decreased on Days 14 through 21 (p < 0.05). Cerebrospinal fluid levels of ADMA correlated directly with the degree of vasospasm (correlation coefficient = 0.7, p = 0.0001; 95% confidence interval: 0.43-0.83). Levels of nitrite and nitrate as well as those of L-citrulline in CSF were decreased in animals with vasospasm. Furthermore, DDAH2 expression was attenuated in the right spastic MCA on Day 7 post-SAH, whereas eNOS and PRMT1 expression remained unchanged. CONCLUSIONS Changes in the CSF levels of ADMA are associated with the development and resolution of vasospasm found on arteriograms after SAH. The results indicate that endogenous inhibition of eNOS by ADMA may be involved in the development of delayed cerebral vasospasm. Inhibition of ADMA production may provide a new therapeutic approach for cerebral vasospasm after SAH.