Miracle-dz/UniFAR-FTUs huggingface dataset:
Models as Approximations — A Conspiracy of Random Regressors and Model Misspecification Against Classical Inference in Regression

Abstract. More than thirty years ago Halbert White inaugurated a “modelrobust” form of statistical inference based on the “sandwich estimator” of standard error. This estimator is known to be “heteroskedasticityconsistent”, but it is less well-known to be “nonlinearity-consistent” as well. Nonlinearity raises fundamental issues because regressors are no longer ancillary, hence can’t be treated as fixed. As a result, (1) the regressor distribution affects the parameters and (2) randomness of the regressors conspires with the nonlinearity to become a source of sampling variability in coefficient estimates. These effects generalize to arbitrary types of regression where regressors have traditionally been treated as ancillary. The generalizations result in a novel notion of misspecification and a re-interpretation of regression parameters as statistical functionals. The cost of a model-robust approach is that the meaning of parameters needs to be rethought and inference needs to be based on model-robust standard errors. For linear OLS, model-trusting standard errors can deviate from “model-robust” standard errors by arbitrary magnitudes. In practice, the two types of standard errors can be compared with a diagnostic test.
Assessing Cultural Competence at a Local Hospital System in the United States

Cultural competence in health care has come to the forefront with the changing demographics in the United States. Standards have been created by the Office of Minority Health for culturally appropriate health care. This article presents the findings of one hospital system's cultural competency assessment. Employee surveys and patient and physician focus groups were conducted to gain insight into cultural differences and challenges encountered in this system. Statistically significant effects of ethnicity and gender on language skills and awareness, as well as differences in awareness and knowledge by the respondent's employment position, were found. Patient concerns included access to care and respect from staff. The need for cross-cultural education and training for all health care delivery personnel was reinforced. Cultural competency will not be achieved if education, attention to diversity, trained interpreters, and the understanding that social factors have a profound influence on health and health outcomes are not considered.
Europe develops action plan to address health workforce shortfall

European officials have developed an action plan to resolve an anticipated shortfall of one million health workers among the 27 member states of the European Union (EU) by 2020. The shortfall will include a need for 230 000 physicians and as a consequence, about 13.5% of necessary health care will
Missing Data and Complex Sample Surveys Using SAS ® : The Impact of Listwise Deletion vs . Multiple Imputation Methods on Point and Interval Estimates when Data are MCAR , MAR , and MNAR

Social scientists from many fields use secondary data analysis of complex sample surveys to answer research questions and test hypotheses. Despite great care taken to obtain the data needed, missing data are frequently found in such samples. Even though missing data is a ubiquitous problem, the methodological literature has provided little guidance to inform the appropriate treatment for such missingness. This Monte Carlo study used SAS® to investigate the impact of missing data treatment (hot deck-based multiple imputations versus regression-based multiple imputation versus listwise deletion) when data are MCAR, MAR, and MNAR. By using 10% to 70% of missing data (along with complete sample conditions as a reference point for interpretation of results), the research focused on the parameter estimates in multiple regression analysis in complex sample data. Results are presented in terms of statistical bias in the parameter estimates and both confidence interval coverage and width.
Alignment-free genome comparison with feature frequency profiles (FFP) and optimal resolutions

For comparison of whole-genome (genic + nongenic) sequences, multiple sequence alignment of a few selected genes is not appropriate. One approach is to use an alignment-free method in which feature (or l-mer) frequency profiles (FFP) of whole genomes are used for comparison—a variation of a text or book comparison method, using word frequency profiles. In this approach it is critical to identify the optimal resolution range of l-mers for the given set of genomes compared. The optimum FFP method is applicable for comparing whole genomes or large genomic regions even when there are no common genes with high homology. We outline the method in 3 stages: (i) We first show how the optimal resolution range can be determined with English books which have been transformed into long character strings by removing all punctuation and spaces. (ii) Next, we test the robustness of the optimized FFP method at the nucleotide level, using a mutation model with a wide range of base substitutions and rearrangements. (iii) Finally, to illustrate the utility of the method, phylogenies are reconstructed from concatenated mammalian intronic genomes; the FFP derived intronic genome topologies for each l within the optimal range are all very similar. The topology agrees with the established mammalian phylogeny revealing that intron regions contain a similar level of phylogenic signal as do coding regions.
Online Pairwise Learning Algorithms

Pairwise learning usually refers to a learning task that involves a loss function depending on pairs of examples, among which the most notable ones are bipartite ranking, metric learning, and AUC maximization. In this letter we study an online algorithm for pairwise learning with a least-square loss function in an unconstrained setting of a reproducing kernel Hilbert space (RKHS) that we refer to as the Online Pairwise lEaRning Algorithm (OPERA). In contrast to existing works (Kar, Sriperumbudur, Jain, & Karnick, 2013; Wang, Khardon, Pechyony, & Jones, 2012), which require that the iterates are restricted to a bounded domain or the loss function is strongly convex, OPERA is associated with a non-strongly convex objective function and learns the target function in an unconstrained RKHS. Specifically, we establish a general theorem that guarantees the almost sure convergence for the last iterate of OPERA without any assumptions on the underlying distribution. Explicit convergence rates are derived under the condition of polynomially decaying step sizes. We also establish an interesting property for a family of widely used kernels in the setting of pairwise learning and illustrate the convergence results using such kernels. Our methodology mainly depends on the characterization of RKHSs using its associated integral operators and probability inequalities for random variables with values in a Hilbert space.
An experimental technique for estimating the aluminum electrolytic capacitor equivalent circuit, at high frequencies

This paper presents an experimental technique that allows the determination of the equivalent circuit of an aluminium electrolytic capacitor. The impedance of these electrolytic capacitors changes with frequency, becoming approximately equal to a resistance near their resonance frequency. This resistance, the equivalent series resistance (ESR), becomes one of the most critical problems of static converters, which operate near the resonant frequency of the capacitor. The ESR leads to a significant increase in the alternating (AC) component of the output voltage, requiring a constant action of the control system. To validate this technique some experimental and simulated results are presented
Deletion of the pflA gene in Escherichia coli LS5218 and its effects on the production of polyhydroxyalkanoates using beechwood xylan as a feedstock

Engineering of microorganisms to directly utilize plant biomass as a feedstock for the biosynthesis of value-added products such as bioplastics is the aim of consolidated bioprocessing. In previous research we successfully engineered E. coli LS5218 to produce polyhydroxyalkanoates (PHAs) from xylan. In this study we report further genetic modifications to Escherichia coli LS5218 in order to increase the lactic acid (LA) fraction in poly(lactic acid-co-3-hydroxyalkanoate) P(LA-co-HA) copolymers. Deletion of the pflA gene resulted in increased content of LA repeating units in the copolymers by over 3-fold compared with the wild type; however, this increase was offset by reduced yields in cell mass. Additionally, when acetate was used as a feedstock LA monomer incorporation reached 18.5 (mol%), which suggests that acetate can be used as a feedstock for the production of P(LA-co-HA) copolymers by E. coli.
Exploring Children's Perceptions of their Local Environment in Relation to Time Spent Outside

This study aims to understand how children perceive their environment, exploring the affordances children perceive to influence their physical activity (PA) behaviour when outside. Participants included boys and girls aged 10–12 years (n = 15) living in Scotland. Children's visual and verbal representations of their perceived environment were analysed to assess environmental determinants of PA. The findings suggested that physical affordances that offer a sense of risk were important to children's play spaces. Social affordances influenced where the children went in their environment and the features they utilised as part of play behaviour; strangers were considered threatening depending on whether the activity was recognised.
1-MHz self-driven ZVS full-bridge converter for 48-V power pod and DC/DC brick

In this paper, a self-driven zero-voltage-switching (ZVS) full-bridge converter is proposed. With the proposed self-driven scheme, the combination of the ZVS technique and Self-driven technique recycles the gate driving energy by making use of the input capacitor of the secondary side synchronous rectifier (SR) as the snubber capacitor of the primary side switches. Compared with the external driver, the proposed converter can save driving loss and synchronous rectifier body diode conduction loss. Additionally, compared with the existed level-shifted self-driven scheme for bridge-type symmetrical topologies, its gate signal is very clean and suitable for high-frequency applications. A 1-MHz, 1.2-V/70-A prototype is built to verify the analysis. Experimental results show that it can achieve 81.7% efficiency. And there is an efficiency improvement of 4.7% over conventional phase-shifted full-bridge converter with an external driver.
LED holographic beam-steering for visible-light communications

Holographic beam-steering is an attractive way to steer optical beams and potentially to engineer the channel matrix in optical multi-input multi-output systems. In visible-light communications, a partially coherent LED is typically used as the optical source. This paper presents a novel algorithm to design beam-steering holograms for such partially coherent sources. Details of the algorithm and experimental results are shown.
Left hippocampal volume loss in Alzheimer's disease is reflected in performance on odor identification: a structural MRI study.

The very high sensitivity and specificity of odor identification tasks in discriminating between Alzheimer's patients and normals suggests that they reflect the presence of underlying neuropathology. Significant neuropathological changes are seen in areas critical to processing olfactory information, even in the early stages of Alzheimer's disease (AD). The current study was designed to investigate whether performance on olfactory tasks (odor threshold and odor identification) was related to volumetric MRI measures of mesial temporal areas central to olfactory information processing and important in the neuropathology of AD. Participants were 8 male and 5 female patients with probable AD, and 10 male and 12 female normal age-matched controls, diagnosed at the UCSD Alzheimer's Disease Research Center. The study investigated correlations between volumetric measures of hippocampus, the parahippocampal gyrus and the amygdala, and the psychophysical measures of olfactory function. Robust relationships were observed between mesial temporal lobe volumes and olfactory functional measures. The finding of a strong relationship between left hippocampal volume and performance on the odor identification task (r = .85) is compatible with a left-hemisphere superiority for verbally mediated olfactory tasks. The findings suggest a neural substrate for the breakdown in functional performance on verbally mediated odor identification tasks in Alzheimer's disease and suggest the utility of quantitative MRI measures and psychophysical performance in the assessment of AD. These results support the potential clinical utility of inclusion of odor identification tests in diagnostic batteries for detecting AD.
A modified Shuffled Frog Leaping algorithm for nonconvex Economic Dispatch problem

This paper presents a new approach to Economic Dispatch (ED) problems with nonconvex cost functions using Shuffled Frog Leaping (SFL) algorithm. The practical ED problems have nonconvex cost functions with equality and inequality constraints that makes the problem of finding the global optimum difficult using any optimization approaches. In this paper, the standard SFL is improved to deal with the equality and inequality constraints in the ED problem. To validate the results obtained by proposed SFL, a modified SFL is adopted from the literature and applied for comparison. Also, the results obtained by the SFL algorithms are compared with other approaches reported in the literature. The results show that the proposed SFL produces better solutions for two study systems due to extra diversification provided by the algorithm.
From microgripping to nanogripping

This paper presents a batch microfabrication approach for processing silicon-on-insulator (SOI) wafers to selectively miniaturize device features to sub-micrometers in thickness. The process was demonstrated to construct gripping devices, reducing the thickness of the gripping tips to 1! m while maintaining a 25µm thickness for all other structural components. Post processing steps were applied to reduce the intrinsic stress of the material layers resulting from the fabrication process, and focused ion beam (FIB) was used optionally to reshape and sharpen the gripper tips. The new devices demonstrated pick and place of 100nm gold nano spheres inside a scanning electron microscope (SEM).
Effect of carbocromen induced coronary vasodilatation on myocardial metabolism in coronary artery disease

Myocardial metabolism was studied during coronary vasodilatation by carbocromen during atrial pacing in patients with coronary arteriosclerotic disease. Coronary sinus flow was measured by the continuous infusion thermodilution technique. Carbocromen increased myocardial flow by the same amount at rest and during pacing‐induced tachycardia. The administration of carbocromen did not interfere with myocardial oxygen consumption, free fatty acid (FFA) uptake, pulmonary or systemic hemodynamics. Atrial pacing above the anginal threshold increased lactate and hypoxanthine excretion to the coronary sinus, but to a greater extent during carbocromen treatment. Thus, carbocromen is a specific coronary vasodilator acting independently of pacing induced vasodilatation. Metabolic data indicate a small but unfavourable effect on ischemic metabolism which might be due to a “coronary steal”.
Activation of mitochondrial lactate uptake by flavone induces apoptosis in human colon cancer cells

Lactate production from glucose even in the presence of oxygen is a characteristic of cancer cell metabolism and an important feature for tumor progression. Here, we describe that an increased uptake of lactate into mitochondria of HT‐29 human colon cancer cells by treatment of cells with the flavonoid flavone is associated with an increased production of mitochondrial superoxide anions and apoptotic cell death. In search of the mitochondrial transporter that could promote enhanced lactate uptake and energetic flow through the electron transport chain, we used fluorescein as a model substrate. Flavone increased fluorescein uptake at pH 7.4 into mitochondria of HT‐29 cells almost tenfold while lactate inhibited uptake significantly. Uptake of fluorescein in the absence or presence of flavone was strongly increased by lowering pH from 7.4 to 6.0 and almost abolished by the protonophore carbonyl cyanide m‐chlorophenylhydrazone (CCCP). The lactate‐sensitive part of fluorescein transport was completely blocked by p‐chloromercuribenzenesulfonic acid (pCMBS), a specific inhibitor of the monocarboxylate transporter‐1 (MCT‐1) that by Western blotting and immunofluorescence was identified in mitochondria of HT‐29 cells. Finally, lactate increased and pCMBS inhibited the flavone‐induced generation of mitochondrial O 2−. radicals and in turn blunted the apoptotic response. In conclusion, our studies provide evidence that flavone reverts the metabolic phenotype of transformed colonocytes towards a phenotype characteristic for normal cells. Transformed colonocytes, however, seem especially vulnerable to O 2−. , produced in mitochondria as a consequence of these metabolic alterations, and respond with the induction of apoptosis. © 2004 Wiley‐Liss, Inc.
Exposure to electromagnetic field attenuates oxygen-glucose deprivation-induced microglial cell death by reducing intracellular Ca2+ and ROS

Abstract Purpose The aim of this research was to demonstrate the protective effects of electromagnetic field (EMF) exposure on the human microglial cell line, HMO6, against ischemic cell death induced by in vitro oxygen-glucose deprivation (OGD). Materials and methods HMO6 cells were cultured for 4 h under OGD with or without exposure to EMF with different combinations of frequencies and intensities (10, 50, or 100 Hz/1 mT and 50 Hz/0.01, 0.1, or 1 mT). Cell survival, intracellular calcium and reactive oxygen species (ROS) levels were measured. Results OGD caused significant HMO6 cell death as well as elevation of intracellular Ca2+ and ROS levels. Among different combinations of EMF frequencies and intensities, 50 Hz/1 mT EMF was the most potent to attenuate OGD-induced cell death and intracellular Ca2+ and ROS levels. A significant but less potent protective effect was also found at 10 Hz/1 mT, whereas no protective effect was found at other combinations of EMF. A xanthine oxidase inhibitor reversed OGD-induced ROS production and cell death, while NADPH oxidase and mitochondrial respiration chain complex II inhibitors did not affect cell death. Conclusions 50 Hz/1 mT EMF protects human microglial cells from OGD-induced cell death by interfering with OGD-induced elevation of intracellular Ca2+ and ROS levels, and xanthine oxidase is one of the main mediators involved in OGD-induced HMO6 cell death. Non-invasive treatment of EMF radiation may be clinically useful to attenuate hypoxic-ischemic brain injury.
Hierarchical key management for mobile ad-hoc networks

Mobile ad-hoc networks (MANETs) face serious security problems due to their unique characteristics such as mobility dynamic topology, and lack of central infrastructure support. In conventional networks, deploying a robust and reliable security mechanism such as public key infrastructure (PKI) requires a central certification authority (CA) or trusted third party to provide fundamental security services including digital certificates, authentication and encryption. In our scheme, distributing the certificate authority functionality among a number of mobile nodes provides distributed, fault tolerant, and hierarchical key management services. It is designed in such a way that each threshold level offers a different level of security, which helps to classify security needs for a wide variety of applications. Performance results prove the effectiveness of our key management scheme.
Ultrafiltrate Analysis Confirms the Specificity of the Selected Method for Plasma Ammonia Determination

The specificity of the direct enzymatic determination of plasma ammonia has hitherto not been unequivocally confirmed, because a suitable comparison method was lacking. Therefore a method variant was elaborated, which includes ultrafiltration to eliminate the high-molecular-mass components regarded as potential sources of unspecificity in the direct measurement procedure according to Rattliff, C.R. & Hall, F. F. (Select. Meth. Clin. Chem. 9, 85-90 (1982)). As the distribution of ammonia during plasma ultrafiltration is markedly influenced by pH and protein concentration, plasma pH is adjusted to 5.5 where the distribution ratio is 1 and nearly independent of actual protein concentration. Acidification significantly diminishes the spontaneous increase of ammonia in plasma at 2-4 degrees C, and the plasma ultrafiltrate is virtually stable. Taking into consideration the slow ammonia formation during sample preparation, excellent agreement was found between ammonia concentrations measured in plasma and in plasma ultrafiltrate, using samples with an apparently normal matrix (n = 30), dysproteinaemia (n = 32) or paraproteinaemia (n = 8). Our data show that the protein matrix of the sample does not cause significant unspecificity in the direct "endpoint" procedure for ammonia determination nor does it affect imprecision. In samples with added bilirubin (up to 252 mumol/l), haemolysate (haemoglobin up to 3.87 g/l) or lipid emulsion (triacylglycerol up to 3.86 mmol/l) ammonia values determined directly in plasma differed maximally by 4% from ultrafiltrate values. A simplified procedure for the ultrafiltration of plasma may be used routinely in clinical service in cases of grossly icteric, haemolytic or turbid samples.
SOX2 anophthalmia syndrome: 12 new cases demonstrating broader phenotype and high frequency of large gene deletions

Background: Developmental eye anomalies, which include anophthalmia (absent eye) or microphthalmia (small eye) are an important cause of severe visual impairment in infants and young children. Heterozygous mutations in SOX2, a SOX1B-HMG box transcription factor, have been found in up to 10% of individuals with severe microphthalmia or anophthalmia and such mutations could also be associated with a range of non-ocular abnormalities. Methods: We performed mutation analysis on a new cohort of 120 patients with congenital eye abnormalities, mainly anophthalmia, microphthalmia and coloboma. Multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridisation (FISH) were used to detect whole gene deletion. Results: We identified four novel intragenic SOX2 mutations (one single base deletion, one single base duplication and two point mutations generating premature translational termination codons) and two further cases with the previously reported c.70del20 mutation. Of 52 patients with severe microphthalmia or anophthalmia analysed by MLPA, 5 were found to be deleted for the whole SOX2 gene and 1 had a partial deletion. In two of these, FISH studies identified sub-microscopic deletions involving a minimum of 328 Kb and 550 Kb. The SOX2 phenotypes include a patient with anophthalmia, oesophageal abnormalities and horseshoe kidney, and a patient with a retinal dystrophy implicating SOX2 in retinal development. Conclusion: Our results provide further evidence that SOX2 haploinsufficiency is a common cause of severe developmental ocular malformations and that background genetic variation determines the varying phenotypes. Given the high incidence of whole gene deletion we recommend that all patients with severe microphthalmia or anophthalmia, including unilateral cases be screened by MLPA and FISH for SOX2 deletions.