Miracle-dz/UniFAR-FTUs huggingface dataset:
Approximate Clustering via Metric Partitioning

In this paper we consider two metric covering/clustering problems - \textit{Minimum Cost Covering Problem} (MCC) and $k$-clustering. In the MCC problem, we are given two point sets $X$ (clients) and $Y$ (servers), and a metric on $X \cup Y$. We would like to cover the clients by balls centered at the servers. The objective function to minimize is the sum of the $\alpha$-th power of the radii of the balls. Here $\alpha \geq 1$ is a parameter of the problem (but not of a problem instance). MCC is closely related to the $k$-clustering problem. The main difference between $k$-clustering and MCC is that in $k$-clustering one needs to select $k$ balls to cover the clients. For any $\eps > 0$, we describe quasi-polynomial time $(1 + \eps)$ approximation algorithms for both of the problems. However, in case of $k$-clustering the algorithm uses $(1 + \eps)k$ balls. Prior to our work, a $3^{\alpha}$ and a ${c}^{\alpha}$ approximation were achieved by polynomial-time algorithms for MCC and $k$-clustering, respectively, where $c > 1$ is an absolute constant. These two problems are thus interesting examples of metric covering/clustering problems that admit $(1 + \eps)$-approximation (using $(1+\eps)k$ balls in case of $k$-clustering), if one is willing to settle for quasi-polynomial time. In contrast, for the variant of MCC where $\alpha$ is part of the input, we show under standard assumptions that no polynomial time algorithm can achieve an approximation factor better than $O(\log |X|)$ for $\alpha \geq \log |X|$.
A forward application of age associated gray and white matter networks

To capture patterns of normal age‐associated atrophy, we previously used a multivariate statistical approach applied to voxel based morphometry that identified age‐associated gray and white matter covariance networks (Brickman et al. [ 2007 ]: Neurobiol Aging 28:284–295). The current study sought to examine the stability of these patterns by forward applying the identified networks to an independent sample of neurologically healthy younger and older adults. Forty‐two younger and 35 older adults were imaged with standard high‐resolution structural magnetic resonance imaging. Individual images were spatially normalized and segmented into gray and white matter. Covariance patterns that were previously identified with scaled subprofile model analyses were prospectively applied to the current sample to identify to what degree the age‐associated patterns were manifested. Older individuals were also assessed with a modified version of the Mini Mental State Examination (mMMSE). Gray matter covariance pattern expression discriminated between younger and older participants with high optimal sensitivity (100%) and specificity (90.5%). While the two groups differed in the degree of white matter pattern expression (t (75) = 5.26, P < 0.001), classification based on white matter expression was relatively low (sensitivity = 80% and specificity = 61.9%). Among older adults, chronological age was significantly associated with increased gray matter pattern expression (r (32) = 0.591, P < 0.001) but not with performance on the mMMSE (r (31) = −0.314, P = 0.085). However, gray matter pattern expression was significantly associated with performance on the mMMSE (r (31) = −0.405, P = 0.024). The findings suggest that the previously derived age‐associated covariance pattern for gray matter is reliable and may provide information that is more functionally meaningful than chronological age. Hum Brain Mapp 2008. © 2007 Wiley‐Liss, Inc.
[Analysis of the patients who missed their appointments at the neurology clinic of the Marina Alta].

OBJECTIVES To analyze the frequency, reasons and characteristics of patients who missed their appointments (NP) at the Neurology Clinic (CEN). To compare the characteristics of the NP with the patients who did not miss their appointment. Suggest measures to reduce avoidable causes of NP. PATIENTS AND METHODS During the period 1/10/99 to 30/4/2000 the cases of NP were prospectively recorded and compared with a sample of patients who attended the CEN during the same period. We analyze the data on age, sex, distance of home from CEN, diagnosis, type of consultation and date of last consultation. The NP were contacted by phone and asked why they had not gone for their appointments. The reasons given were then classified as avoidable or unavoidable. RESULTS Of the 1,842 consultations scheduled, 19% were NP. When the NP and the patients who did attend were compared we found statistically significant differences regarding the distance home/CEN. According to the diagnosis, the NP had more 'symptoms/signs' and other MIA, whilst those who attended the clinic had more 'neuropathies' and 'awaiting diagnosis'. The commonest avoidable reasons (55.8%) for NP were forgetting, administrative error and communication failure, and for unavoidable reasons (44.2%) physical disability, other priorities and improvement. CONCLUSIONS There is a large proportion of NP in the CEN of the Marina Alta. The distance from home to CEN (over 25 km) was the main factor affecting the rate of NP. Since 56% of the NP were due to avoidable causes, strategies could be designed to reduce this percentage. In the NP group, the main causes were forgetting, administrative errors and communication failure.
Correlation in a Bayesian framework

The authors consider the correlation between two arbitrary functions of the data and a parameter when the parameter is regarded as a random variable with given prior distribution. They show how to compute such a correlation and use closed form expressions to assess the dependence between parameters and various classical or robust estimators thereof, as well as between p‐values and posterior probabilities of the null hypothesis in the one‐sided testing problem. Other applications involve the Dirichlet process and stationary Gaussian processes. Using this approach, the authors also derive a general nonparametric upper bound on Bayes risks.
Application of essential work of fracture concept to toughness characterization of high-density polyethylene

Deformation and fracture toughness of high-density polyethylene (HDPE) in plane-stress tension was studied using the concept of essential work of fracture (EWF). Strain range for necking was determined from uniaxial tensile test, and was used to explain the deformation transition for 2-staged crack growth in double-edge-notched tensile test. Through work-partitioning, EWF values for HDPE were determined for each stage of the crack growth. Appropriateness of these EWF values to represent the material toughness is discussed. The study concludes that the EWF values for ductile polymers like HDPE may not be constant, but vary with the deformation behaviour involved in the crack growth process. POLYM. ENG. SCI., 47:1327–1337, 2007. © 2007 Society of Plastics Engineers
SMOOTH OPTIMIZATION APPROACH FOR SPARSE COVARIANCE SELECTION∗

In this paper we first study a smooth optimization approach for solving a class of nonsmooth strictly concave maximization problems whose objective functions admit smooth convex minimization reformulations. In particular, we apply Nesterov’s smooth optimization technique [Y. E. Nesterov, Dokl. Akad. Nauk SSSR, 269 (1983), pp. 543–547; Y. E. Nesterov, Math. Programming, 103 (2005), pp. 127–152] to their dual counterparts that are smooth convex problems. It is shown that the resulting approach has O(1/ √ ) iteration complexity for finding an -optimal solution to both primal and dual problems. We then discuss the application of this approach to sparse covariance selection that is approximately solved as an l1-norm penalized maximum likelihood estimation problem, and also propose a variant of this approach which has substantially outperformed the latter one in our computational experiments. We finally compare the performance of these approaches with other first-order methods, namely, Nesterov’s O(1/ ) smooth approximation scheme and blockcoordinate descent method studied in [A. d’Aspremont, O. Banerjee, and L. El Ghaoui, SIAM J. Matrix Anal. Appl. , 30 (2008), pp. 56–66; J. Friedman, T. Hastie, and R. Tibshirani, Biostatistics, 9 (2008), pp. 432–441] for sparse covariance selection on a set of randomly generated instances. It shows that our smooth optimization approach substantially outperforms the first method above, and moreover, its variant substantially outperforms both methods above.
A comprehensive study of deep bidirectional LSTM RNNS for acoustic modeling in speech recognition

Recent experiments show that deep bidirectional long short-term memory (BLSTM) recurrent neural network acoustic models outperform feedforward neural networks for automatic speech recognition (ASR). However, their training requires a lot of tuning and experience. In this work, we provide a comprehensive overview over various BLSTM training aspects and their interplay within ASR, which has been missing so far in the literature. We investigate on different variants of optimization methods, batching, truncated backpropagation, and regularization techniques such as dropout, and we study the effect of size and depth, training models of up to 10 layers. This includes a comparison of computation times vs. recognition performance. Furthermore, we introduce a pretraining scheme for LSTMs with layer-wise construction of the network showing good improvements especially for deep networks. The experimental analysis mainly was performed on the Quaero task, with additional results on Switchboard. The best BLSTM model gave a relative improvement in word error rate of over 15% compared to our best feed-forward baseline on our Quaero 50h task. All experiments were done using RETURNN and RASR, RWTH's extensible training framework for universal recurrent neural networks and ASR toolkit. The training configuration files are publicly available.
The prevalence of hypertension and its modifiable risk factors among lecturers of a medical school in Port Harcourt, south-south Nigeria: implications for control effort.

BACKGROUND Hypertension and other noncommunicable diseases are currently responsible for at least 20% of all deaths in Nigeria, and constitute up to 60% of the patients admitted into the medical wards of most tertiary hospitals in Nigeria. Yet, the treatment outcomes for the diseases have remained very poor, prompting calls for better patient education. It has however been established that the effectiveness of patient education is linked to the healthy habits of the doctor. This study was conducted to find out the prevalence of hypertension and its modifiable risk factors among the lecturers of the University of Port Harcourt Medical School. MATERIALS AND METHODS A descriptive cross-sectional study design was used, with the data collected using a modified form of the WHO STEPS instrument that consists of a questionnaire component and the measurement of body mass index (BMI) and blood pressure. The questionnaire was used to collect information on the sociodemographic characteristics of the respondents, the use of tobacco, the consumption of alcohol, the type of diet, and the amount and types of physical activities undertaken. RESULTS A total of 75 lecturers participated fully in the study, out of an eligible total of 109. They were mostly males (65.33%), married (88.33%), and had an average age of 46.06 ± 9.62 years. The prevalence of hypertension was 21.33%; out of which 12 (75.00%) were already aware of their status, and were on appropriate therapy. Only 13 (17.33%) of the lecturers were of normal weight, 45 (60.00%) were overweight, while 17 (22.67%) were obese. Only 2 (2.67%) currently smoke, while most (94.67%) drank less than three standard units of alcohol in a day, mainly in social occasions. CONCLUSION The prevalence of hypertension among the lecturers in the medical school was lower than that in the general population, mainly due to their better health-seeking behavior and healthy lifestyle.
Corticosterone, testosterone and life-history strategies of birds

Steroid hormones have similar functions across vertebrates, but circulating concentrations can vary dramatically among species. We examined the hypothesis that variation in titres of corticosterone (Cort) and testosterone (T) is related to life-history traits of avian species. We predicted that Cort would reach higher levels under stress in species with higher annual adult survival rates since Cort is thought to promote physiological and behavioural responses that reduce risk to the individual. Conversely, we predicted that peak T during the breeding season would be higher in short-lived species with high mating effort as this hormone is known to promote male fecundity traits. We quantified circulating hormone concentrations and key life-history traits (annual adult survival rate, breeding season length, body mass) in males of free-living bird species during the breeding season at a temperate site (northern USA) and a tropical site (central Panama). We analysed our original data by themselves, and also combined with published data on passerine birds to enhance sample size. In both approaches, variation in baseline Cort (Cort0) among species was inversely related to breeding season length and body mass. Stress-induced corticosterone (MaxCort) also varied inversely with body mass and, as predicted, also varied positively with annual adult survival rates. Furthermore, species from drier and colder environments exhibited lower MaxCort than mesic and tropical species; T was lowest in species from tropical environments. These findings suggest that Cort0, MaxCort and T modulate key vertebrate life-history responses to the environment, with Cort0 supporting energetically demanding processes, MaxCort promoting survival and T being related to mating success.
Socioeconomic Status and Clustering of Cardiovascular Disease Risk Factors in Diabetic Patients

OBJECTIVE Correction of cardiovascular risk factors is an essential component of good diabetes care. Our goal was to examine the relationship of socioeconomic status in five risk factors: obesity, hypertension, high cholesterol, smoking, and high HbA1c. RESEARCH DESIGN AND METHODS We conducted a cross-sectional prevalence study of all patients with diabetes (n = 1,553) attending a clinic in Glasgow, U.K. Area-based codes were used to measure socioeconomic status; these ranged from 1, the most affluent, to 7, the most deprived. RESULTS Comparing patients with NIDDM from the seven categories of socioeconomic status, we found that those from deprived categories experienced a higher prevalence of obesity. In the most affluent groups, 30% had a BMI > 30 kg/m2 compared with 47% in the most deprived categories (P < 0.002). With regard to smoking, 13% in the most affluent category smoked compared with 33% in the most deprived (P < 0.001). In patients with IDDM from affluent categories, 13% smoked compared with 34% from deprived categories (P < 0.001). The proportion of patients with no cardiac risk factors fell by 30.6% from deprived category 1 to 7 (P < 0.001), and the proportion of patients with three or more risk factors rose from 8.6% in category 1 to 20.2% in category 7. CONCLUSIONS Diabetic patients from areas of low socioeconomic status are at increased risk of cardiovascular disease. To counter this, specific health education programs should be evolved and resources should be directed toward these areas.
Vascular Plant Communities Associated with Black-Tailed Prairie Dog Colonies in Southern Shortgrass Prairie

The black-tailed prairie dog (Cynomys ludovicianus), a large burrowing rodent found in grasslands of the western Great Plains, once occurred over approximately 40 million ha before European settlement (13). Prairie dogs (C. ludovicianus, C. leucurus, C. gunnisoni, and C. parvidens) covered approximately 283 million ha in the late 1800s Vascular Plant Communities Associated with Black-tailed Prairie Dog Colonies in Southern Shortgrass Prairie
Hepatic tumors treated with percutaneous radio-frequency ablation: CT and MR imaging follow-up.

PURPOSE To describe the appearance of hepatic tumors treated with radio-frequency (RF) ablation on computed tomographic (CT) and magnetic resonance (MR) images and the pattern of residual tumor at the site of RF ablation and to assess prospectively the sensitivity, specificity, and positive and negative predictive CT and MR imaging values in the evaluation of RF treatment. MATERIALS AND METHODS Thirty-one patients with 50 tumors (nine hepatocellular carcinomas and 41 metastases) treated with RF ablation underwent CT and MR imaging on the same day at 2, 4, and 6 months; CT was performed every 3 months thereafter. CT and MR findings were interpreted separately and prospectively by two reviewers with consensus. For both imaging techniques, appearance of the treated area, treatment efficacy, and complications were assessed at each time. Sensitivity and specificity were determined by using the McNemar test. RESULTS After a mean follow-up of 19 months, nine tumors showed local regrowth. At 2 months, MR imaging depicted more local regrowths (eight of nine; sensitivity, 89%) than did CT (four of nine; sensitivity, 44%) but without significant differences (P =.12). In two cases, only T2-weighted imaging depicted local regrowth. All nine lesions became conspicuous at 4-month follow-up with both techniques. At 2 months, thin peripheral rim enhancement and arterioportal shunting were found in 24% and 12%, respectively, of the treated tumors. These findings disappeared thereafter and are not linked to tumor regrowth. CONCLUSION Despite the small number of patients, CT and MR imaging may depicted all local regrowth at 4 months or sooner. MR imaging may have an edge over CT in the early detection of local regrowth.
On the challenge of classifying 52 hand movements from surface electromyography

The level of dexterity of myoelectric hand prostheses depends to large extent on the feature representation and subsequent classification of surface electromyography signals. This work presents a comparison of various feature extraction and classification methods on a large-scale surface electromyography database containing 52 different hand movements obtained from 27 subjects. Results indicate that simple feature representations as Mean Absolute Value and Waveform Length can achieve similar performance to the computationally more demanding marginal Discrete Wavelet Transform. With respect to classifiers, the Support Vector Machine was found to be the only method that consistently achieved top performance in combination with each feature extraction method.
Birth outcome in women with breast cancer, cutaneous malignant melanoma, or Hodgkin’s disease: a review

Background Data on birth outcome in women diagnosed with cancer before, during, or shortly after pregnancy are very sparse. The purpose of this review was to summarize the existing epidemiologic evidence of the adverse effect of breast cancer, cutaneous malignant melanoma, and Hodgkin’s disease on birth outcome. Methods The MEDLINE database was used to review the literature systematically. Studies that examined the following outcomes were included: preterm birth, low birth weight, low birth weight at term, stillbirths, congenital abnormalities, male proportion of newborns, and mean birth weight. Studies were grouped according to whether the woman had been diagnosed with the specific cancer before, during, or shortly after pregnancy. Results Few data exist on birth outcome in women with breast cancer, melanoma, or Hodgkin’s disease. The overall results from the limited number of studies, which included a comparison group for birth outcome, were reassuring. However, for women diagnosed with breast cancer before pregnancy, the only 2 studies that included comparison groups for birth outcome had conflicting results regarding the risk of preterm birth and congenital abnormalities. Furthermore, a recent cohort study of birth outcome in women who were diagnosed with Hodgkin’s disease before pregnancy indicated a slightly increased risk of congenital abnormalities among the newborns. Conclusion Overall, the existing studies offer reassuring results concerning the risks of adverse birth outcome for women diagnosed with breast cancer, melanoma, or Hodgkin’s disease before, during or shortly after pregnancy. A limitation of most studies was the imprecise risk estimates caused by the small number of adverse birth outcomes and the lack of results stratified by treatment. Therefore, international collaboration is necessary in the future, to obtain more precise risk estimates for adverse birth outcomes, and to allow stratified analyses according to, for example, treatment.
[Attitudes to estrogen replacement therapy among Norwegian women].

BACKGROUND The aim of the study was to investigate women's attitudes towards hormone treatment (HT), their judgment of the various sources of information, and their knowledge of indications for HT. METHODS We posted questionnaires to 1000 Norwegian women between 45 and 60 years of age, randomly selected from the National Register. We received replies from 386 women (38.6%). RESULTS Of those who replied, 28% reported that they were currently using HT, 22% were previous users, 24% were considering starting, whereas 26% refused ever to use HT. One half of current and previous users had obtained their prescriptions from a gynaecologist, the other half from their general practitioner. Mean age at start of HT was 47 years. 65% of the women started the medication before menopause. The women thought HT to be useful for treatment of hot flushes, prevention of osteoporosis, well-being, improved mood and sex life. The women were also asked about the rating of importance that they would give to the various sources of information. The highest ratings were given to their gynaecologist or general practitioner. Also reading about HT and the opinion of other health personnel obtained high ratings. CONCLUSIONS The indications for HT given by the women correspond well with the prevailing guidelines. The recent observation about a possible negative effect of HT on cardiovascular disease seems to have reached the respondents. Many women begin to use HT several years before menopause.
A hybrid layout algorithm for sub-quadratic multidimensional scaling

Many clustering and layout techniques have been used for structuring and visualising complex data. This paper is inspired by a number of such contemporary techniques and presents a novel hybrid approach based upon stochastic sampling, interpolation and spring models. We use Chalmers' 1996 O(N/sup 2/) spring model as a benchmark when evaluating our technique, comparing layout quality and run times using data sets of synthetic and real data. Our algorithm runs in O(N/spl radic/N) and executes significantly faster than Chalmers' 1996 algorithm, whilst producing superior layouts. In reducing complexity and run time, we allow the visualisation of data sets of previously infeasible size. Our results indicate that our method is a solid foundation for interactive and visual exploration of data.
Brief report: Maltreatment in childhood and body concerns in adulthood

Objective: We examined the relationship between maltreatment in childhood and body concerns in adulthood. Method: A community sample of 156 women and 143 men completed measures of maltreatment – frequency of sexual abuse, physical abuse, physical neglect, emotional abuse and emotional neglect – in childhood. They also reported current dissatisfaction with body weight and shape and drive for thinness and drive for muscle. Results and conclusions: Childhood maltreatment was associated with drive for muscle in women and body dissatisfaction and drive for thinness in men. The results provide some evidence that adverse conditions in childhood can be associated with gender-atypical body concerns in adulthood.