Miracle-dz/UniFAR-FTUs huggingface dataset:
An improved approximation algorithm for the column subset selection problem

We consider the problem of selecting the "best" subset of exactly k columns from an m x n matrix A. In particular, we present and analyze a novel two-stage algorithm that runs in O(min{mn2, m2n}) time and returns as output an m x k matrix C consisting of exactly k columns of A. In the first stage (the randomized stage), the algorithm randomly selects O(k log k) columns according to a judiciously-chosen probability distribution that depends on information in the top-k right singular subspace of A. In the second stage (the deterministic stage), the algorithm applies a deterministic column-selection procedure to select and return exactly k columns from the set of columns selected in the first stage. Let C be the m x k matrix containing those k columns, let PC denote the projection matrix onto the span of those columns, and let Ak denote the "best" rank-k approximation to the matrix A as computed with the singular value decomposition. Then, we prove that [EQUATION] with probability at least 0.7. This spectral norm bound improves upon the best previously-existing result (of Gu and Eisenstat [21]) for the spectral norm version of this Column Subset Selection Problem. We also prove that [EQUATION] with the same probability. This Frobenius norm bound is only a factor of √k log k worse than the best previously existing existential result and is roughly O(√k! ) better than the best previous algorithmic result (both of Deshpande et al. [11]) for the Frobenius norm version of this Column Subset Selection Problem.
Residents’ perceptions of the impacts of a carnival in Cape Town

Carnival events have become a significant factor in tourism development initiatives of most destinations. The economic and socio-cultural developments experienced by host communities of tourism attractions and resorts have led to the emergence of carnival events as useful destination products. However, an understanding of residents’ perceptions of event impacts on the area where they reside is necessary in order to gain local support for the event and tourism in general. Effects of carnival events at the personal level are increasingly being explored in tourism research. This is an exciting line of research since carnival events are being increasingly used to implement a wide range of public sector policies aimed at enhancing tourism offerings. The aim of this study is to examine residents’ perceptions of the impact of a carnival in Cape Town in order to establish the overall value of the event. The study explores the perceptions of Green Point suburb residents on the Cape Town Carnival event highlighting the positive and negative aspects of their experience with the event. This study will add to the understudied event in Cape Town and advance academic discourse on carnival events. The findings show that residents are in support of the event being hosted in their area. However recommendations to the identified problems such as limited parking and traffic congestion, drunkbehaviors and littering associated to the event are proposed.
University of Groningen Structure-function relationships of family GH70 glucansucrase and 4,6-α-glucanotransferase enzymes, and their evolutionary relationships with family GH13 enzymes

Lactic acid bacteria (LAB) are known to produce large amounts of a-glucan exopolysaccharides. Family GH70 glucansucrase (GS) enzymes catalyze the synthesis of these a-glucans from sucrose. The elucidation of the crystal structures of representative GS enzymes has advanced our understanding of their reaction mechanism, especially structural features determining their linkage specificity. In addition, with the increase of genome sequencing, more and more GS enzymes are identified and characterized. Together, such knowledge may promote the synthesis of a-glucans with desired structures and properties from sucrose. In the meantime, two new GH70 subfamilies (GTFBand GTFC-like) have been identified as 4,6-a-glucanotransferases (4,6-a-GTs) that represent novel evolutionary intermediates between the family GH13 and ‘‘classical GH70 enzymes’’. These enzymes are not active on sucrose; instead, they use (a1 ? 4) glucans (i.e. malto-oligosaccharides and starch) as substrates to synthesize novel a-glucans by introducing linear chains of (a1 ? 6) linkages. All these GH70 enzymes are very interesting biocatalysts and hold strong potential for applications in the food, medicine and cosmetic industries. In this review, we summarize the microbiological distribution and the structure–function relationships of family GH70 enzymes, introduce the two newly identified GH70 subfamilies, and discuss evolutionary relationships between family GH70 and GH13 enzymes.
Cellular reprogramming of human monocytes is regulated by time-dependent IL4 signalling and NCOR2

The clinical and therapeutic value of human in vitro generated monocyte-derived dendritic cell (moDC) and macrophages is well established. However, in line with recent findings regarding myeloid cell ontogeny and due to our limited understanding of their physiological counterparts, transcriptional regulation and heterogeneity, the full potential of these important cellular systems is still underestimated. In this study, we use cutting edge high-dimensional analysis methods to better understand the transcriptional organization, phenotypic heterogeneity and functional differences between human ex vivo isolated and in vitro generated mononuclear phagocytes with the aim to better realize their full potential in the clinic. We demonstrate that human monocytes activated by MCSF or GMCSF most closely resemble inflammatory macrophages identified in vivo, while IL4 signalling in the presence of GMCSF generates moDCs resembling inflammatory DCs in vivo, but not steady state cDC1 or cDC2. Moreover, these reprogramming regimes lead to activated monocytes that present with profoundly different transcriptomic, metabolic, phenotypic and functional profiles. Furthermore, we demonstrate that CD14+ monocytes are integrating multiple exogenous activation signals such as GMCSF and IL4 in a combinatorial and temporal fashion, resulting in a high-dimensional cellular continuum of reprogrammed monocytes dependent on the mode and timing of cytokine exposure. Utilizing nanostraw-based knockdown technology, we demonstrate that the IL4-dependent generation of moDCs relies on the induction, nuclear localization and function of the transcriptional regulator NCOR2. Finally, we unravel unappreciated heterogeneity within the clinically moDCs population and propose a novel high-dimensional phenotyping strategy to better tailor clinical quality control strategies for patient need and culture conditions to enhance therapeutic outcome.
Semi-supervised multi-task learning for predicting interactions between HIV-1 and human proteins

Motivation: Protein–protein interactions (PPIs) are critical for virtually every biological function. Recently, researchers suggested to use supervised learning for the task of classifying pairs of proteins as interacting or not. However, its performance is largely restricted by the availability of truly interacting proteins (labeled). Meanwhile, there exists a considerable amount of protein pairs where an association appears between two partners, but not enough experimental evidence to support it as a direct interaction (partially labeled). Results: We propose a semi-supervised multi-task framework for predicting PPIs from not only labeled, but also partially labeled reference sets. The basic idea is to perform multi-task learning on a supervised classification task and a semi-supervised auxiliary task. The supervised classifier trains a multi-layer perceptron network for PPI predictions from labeled examples. The semi-supervised auxiliary task shares network layers of the supervised classifier and trains with partially labeled examples. Semi-supervision could be utilized in multiple ways. We tried three approaches in this article, (i) classification (to distinguish partial positives with negatives); (ii) ranking (to rate partial positive more likely than negatives); (iii) embedding (to make data clusters get similar labels). We applied this framework to improve the identification of interacting pairs between HIV-1 and human proteins. Our method improved upon the state-of-the-art method for this task indicating the benefits of semi-supervised multi-task learning using auxiliary information. Availability: http://www.cs.cmu.edu/∼qyj/HIVsemi Contact: qyj@cs.cmu.edu
Endoscopic surgical treatment of laryngotracheal clefts: indications and limitations.

OBJECTIVE To present the indications, techniques, results, and limitations of endoscopic surgical treatment of laryngotracheal cleft. DESIGN Retrospective case note study (2005-2009). SETTING Department of Otolaryngology-Head and Neck Surgery, Armand Trousseau Children's Hospital, Paris, France. PATIENTS Eleven patients who underwent endoscopic cleft closure as a primary (n = 8) or secondary (n = 3) procedure among 22 patients treated for laryngotracheal clefts. We report patients' demographics, symptoms leading to the diagnosis, endoscopic evaluation method, medical examination results, and surgical techniques. INTERVENTION Endoscopic closure of the cleft under spontaneous ventilation via 2-layer interrupted sutures after excision of the mucosal edge using a carbon dioxide laser in 10 patients and a thulium laser in 1. MAIN OUTCOME MEASURES Analysis of postoperative complications, revision surgery, need for intensive care unit admission, closure of the cleft, and long-term symptom results. RESULTS Successful closure of the 11 clefts (with revision surgery in 3 patients) without the need for intubation or intensive care unit admission enabled the elimination of aspiration in 10 patients and significant improvement in 1 patient with bilateral vocal cord paralysis. There were no significant postoperative complications. CONCLUSIONS Endoscopic closure of laryngotracheal clefts is a reliable technique that significantly reduces perioperative and postoperative morbidity. The results of this technique are entirely satisfactory, and we suggest that it is suitable as a primary procedure for the treatment of type I, II, and III clefts extending to the cervical trachea, including in neonates.
The Role of the Caudal Superior Parietal Lobule in Updating Hand Location in Peripheral Vision: Further Evidence from Optic Ataxia

Patients with optic ataxia (OA), who are missing the caudal portion of their superior parietal lobule (SPL), have difficulty performing visually-guided reaches towards extra-foveal targets. Such gaze and hand decoupling also occurs in commonly performed non-standard visuomotor transformations such as the use of a computer mouse. In this study, we test two unilateral OA patients in conditions of 1) a change in the physical location of the visual stimulus relative to the plane of the limb movement, 2) a cue that signals a required limb movement 180° opposite to the cued visual target location, or 3) both of these situations combined. In these non-standard visuomotor transformations, the OA deficit is not observed as the well-documented field-dependent misreach. Instead, OA patients make additional eye movements to update hand and goal location during motor execution in order to complete these slow movements. Overall, the OA patients struggled when having to guide centrifugal movements in peripheral vision, even when they were instructed from visual stimuli that could be foveated. We propose that an intact caudal SPL is crucial for any visuomotor control that involves updating ongoing hand location in space without foveating it, i.e. from peripheral vision, proprioceptive or predictive information.
Prevalence and Occupational Impact of Arthritis in Saskatchewan Farmers

ABSTRACT Agricultural workers have physically demanding occupations. In this study of Saskatchewan farmers, the authors examined (1) self-reported prevalence of physician-diagnosed rheumatoid arthritis and osteoarthritis; and (2) the impact of these chronic arthridities on engagement in physical tasks related to farming. This study was conducted through a cross-sectional analysis of baseline data from the Saskatchewan Farm Injury Cohort Study in which 2,473 adult residents upon 1,216 farms participated. Collected survey data included demographic and health information; regional musculoskeletal symptoms for each participant assessed via the Standard Nordic Questionnaire; and engagement in various specific physical tasks or activities associated with mixed farming practices. Of the 2,473 respondents, 13% reported chronic arthritic diagnoses (10% osteoarthritis, 4% rheumatoid arthritis, with 1% from each category overlapping with both forms of arthritis). Participants reporting arthritis were more likely to also report disabling musculoskeletal symptoms involving their shoulders, elbows, hands, lower back, hips, knees, and ankles. Farmers with arthritis reported less participation in all physical farming activities studied, including various machinery operations, herd maintenance and veterinary activities, overhead work, shoveling/pitchfork work, and lifting/carrying. When adjusted for age, gender, and comorbidities, operation of combines and shoveling/pitchfork work continued to be significantly less engaged in by farmers with arthritis. The overall prevalence of arthritis was consistent with general population prevalence, although the category of rheumatoid arthritis was overrepresented. Farmers with arthritis were significantly less likely to participate in combine operation and shoveling/pitchfork chores compared with their counterparts without arthritis.
Viscosity of Fluids in Subduction Zones

The viscosities of aqueous fluids with 10 to 80 weight percent dissolved silicates have been measured at 600° to 950°C and 1.0 to 2.0 gigapascals by in situ observation of falling spheres in the diamond anvil cell. The viscosities at 800°C range from 10–4 to 100.5 pascal seconds. The combination of low viscosities with a favorable wetting angle makes silicate-rich fluid an efficient agent for material transport at low-volume fractions. Our results therefore suggest that there may be a direct relationship between the position of the volcanic front and the onset of complete miscibility between water and silicate melt in the subducting slab.
Effects of Fluoride Dentifrices on Enamel Lesion Formation

An in vitro pH cycling model was used to test the hypothesis that the effects of 3 different fluoride compounds on de/remineralization are a function of the free fluoride ion concentration. Groups of 10 human enamel specimens were treated with one of: (a) amine fluoride (AmF), 1250 ppm F; (b) sodium monofluorophosphate (NaMFP), 1000 ppm F; (c) sodium fluoride (NaF), 1100 ppm F; (d) NaF, 250 ppm F; (e) Placebo (< 1 ppm F) dentifrices; or with aqueous solutions (f) NaF 900 ppm F or (g) NaF 30 ppm F. Lesions were assessed by cross-sectional microhardness. Mean ± SEM ΔZ (vol.% x μm) values of 3 dentifrices were: (a) 344 ± 155, (b) 4259 ± 257, and (c) 591 ± 83. The AmF (1250 ppm F) was not statistically significantly different from the NaF (1100 ppm F) dentifrice in this model. The NaMFP (1000 ppm F) dentifrice, without hydrolysis, had only the same efficacy as the NaF (30 ppm F) aqueous solution.
A Fast and Provable Method for Estimating Clique Counts Using Turán's Theorem

Clique counts reveal important properties about the structure of massive graphs, especially social networks. The simple setting of just 3-cliques (triangles) has received much attention from the research community. For larger cliques (even, say 6-cliques) the problem quickly becomes intractable because of combinatorial explosion. Most methods used for triangle counting do not scale for large cliques, and existing algorithms require massive parallelism to be feasible. We present a new randomized algorithm that provably approximates the number of k-cliques, for any constant k. The key insight is the use of (strengthenings of) the classic Turán's theorem: this claims that if the edge density of a graph is sufficiently high, the k-clique density must be non-trivial. We define a combinatorial structure called a Turàn shadow, the construction of which leads to fast algorithms for clique counting. We design a practical heuristic, called TURÀN-SHADOW, based on this theoretical algorithm, and test it on a large class of test graphs. In all cases, TURÀN-SHADOW has less than 2% error, in a fraction of the time used by well-tuned exact algorithms. We do detailed comparisons with a range of other sampling algorithms, and find that TURÀN-SHADOW is generally much faster and more accurate. For example, TURÀN-SHADOW estimates all cliques numbers up to size 10 in social network with over a hundred million edges. This is done in less than three hours on a single commodity machine.
Segmenting Retinal Blood Vessels With Deep Neural Networks

The condition of the vascular network of human eye is an important diagnostic factor in ophthalmology. Its segmentation in fundus imaging is a nontrivial task due to variable size of vessels, relatively low contrast, and potential presence of pathologies like microaneurysms and hemorrhages. Many algorithms, both unsupervised and supervised, have been proposed for this purpose in the past. We propose a supervised segmentation technique that uses a deep neural network trained on a large (up to 400 \thinspace000) sample of examples preprocessed with global contrast normalization, zero-phase whitening, and augmented using geometric transformations and gamma corrections. Several variants of the method are considered, including structured prediction, where a network classifies multiple pixels simultaneously. When applied to standard benchmarks of fundus imaging, the DRIVE, STARE, and CHASE databases, the networks significantly outperform the previous algorithms on the area under ROC curve measure (up to > 0.99) and accuracy of classification (up to > 0.97). The method is also resistant to the phenomenon of central vessel reflex, sensitive in detection of fine vessels ( sensitivity > 0.87), and fares well on pathological cases.
Ecological and economic impacts of exotic fish species on fisheries in the Pearl River basin

The Pearl River basin has the highest fish diversity in China and has been identified as a global hotspot of fish biodiversity. Twenty-three exotic fish species are distributed in the Pearl River basin, tilapias, North African catfish, roho labeo, and mrigal carp have become important exotic species to the local fisheries economy. We investigated catches in the Pearl River basin using an isometric random sampling method and analyzed the ecological and economic impacts of exotic species. The results show that the biomass percentage of exotic species in the upper reaches of the Pearl River basin was higher than that in other regions, and was higher in the drought season than in the flood season. Pearson correlation analysis indicated that the abundances of exotic species were significantly positively correlated, which indicates that they might have joint impacts. Although exotic species enhance fishing production, they decrease the income of fishermen. A multiple linear model indicated that as the biomass percentage of exotic species increased by one percent, the income decreased by 20.19 RMB/vessel/month (RMB, Ren Min Bi, Chinese currency) at a given site. This inevitably caused the fishermen to catch more fish to increase their income. It is urgent to assess the invasion potential of introduced species in southern China and limit both the biomass and spread of exotic species.
Topographically specific hippocampal projections target functionally distinct prefrontal areas in the rhesus monkey

The sources of ipsilateral projections from the hippocampal formation, the presubiculum, area 29a‐c, and parasubiculum to medial, orbital, and lateral prefrontal cortices were studied with retrograde tracers in 27 rhesus monkeys. Labeled neurons within the hippocampal formation (CA1, CA1′, prosubiculum, and subiculum) were found rostrally, although some were noted throughout the entire rostrocaudal extent of the hippocampal formation. Most labeled neurons in the hippocampal formation projected to medial prefrontal cortices, followed by orbital areas. In addition, there were differences in the topography of afferent neurons projecting to medial when compared with orbital cortices. Labeled neurons innervating medial cortices were found mainly in the CA1′ and CA1 fields rostrally, but originated in the subicular fields caudally. In contrast, labeled neurons which innervated orbital cortices were considerably more focal, emanating from the same relative position within a field throughout the rostrocaudal extent of the hippocampal formation.
Intraoperative assessment of the stability of the distal tibiofibular joint in supination-external rotation injuries of the ankle: sensitivity, specificity, and reliability of two clinical tests.

BACKGROUND This study was designed to assess the sensitivity, specificity, and interobserver reliability of the hook test and the stress test for the intraoperative diagnosis of instability of the distal tibiofibular joint following fixation of ankle fractures resulting from supination-external rotation forces. METHODS We conducted a prospective study of 140 patients with an unstable unilateral ankle fracture resulting from a supination-external rotation mechanism (Lauge-Hansen SE). After internal fixation of the malleolar fracture, a hook test and an external rotation stress test under fluoroscopy were performed independently by the lead surgeon and assisting surgeon, followed by a standardized 7.5-Nm external rotation stress test of each ankle under fluoroscopy. A positive stress test result was defined as a side-to-side difference of >2 mm in the tibiotalar or the tibiofibular clear space on mortise radiographs. The sensitivity and specificity of each test were calculated with use of the standardized 7.5-Nm external rotation stress test as a reference. RESULTS Twenty-four (17%) of the 140 patients had a positive standardized 7.5-Nm external rotation stress test after internal fixation of the malleolar fracture. The hook test had a sensitivity of 0.25 (95% confidence interval, 0.12 to 0.45) and a specificity of 0.98 (95% confidence interval, 0.94 to 1.0) for the detection of the same instabilities. The external rotation stress test had a sensitivity of 0.58 (95% confidence interval, 0.39 to 0.76) and a specificity of 0.96 (95% confidence interval, 0.90 to 0.98). Both tests had excellent interobserver reliability, with 99% agreement for the hook test and 98% for the stress test. CONCLUSIONS Interobserver agreement for the hook test and the clinical stress test was excellent, but the sensitivity of these tests was insufficient to adequately detect instability of the syndesmosis intraoperatively.