Miracle-dz/UniFAR-FTUs huggingface dataset:
Comments on propensity score matching following multiple imputation

In a recently published simulation study, Mitra and Reiter compared two approaches to implementing propensity score (PS) methods following multiple imputation. Particular emphasis was on PS matching following multiple imputation. In simulation studies, they evaluated two possible approaches, i.e. the so-called Within and Across approaches. In both approaches, PSs are estimated in each of m imputed datasets. In the Within approach, PS matching is performed within each imputed dataset. The resulting m effect estimates are then pooled by averaging. In the Across approach, for each subject the m estimated PSs are averaged first, after which PS matching is performed once, based on each subject’s average PS. Apparent from the results was the trend that although both approaches were biased, the Within method was generally more biased than the Across approach, particularly when there was missing confounder data. We argue that these findings are due to the imputation model and the matching algorithm rather than a genuine difference between the methods. While Mitra and Reiter chose to leave the outcome out of the imputation model, it has been shown that often the outcome should actually be included in the imputation model. To illustrate this, we repeated a selection of Mitra and Reiter’s simulations, which represent a setting of a binary treatment, a continuous outcome, and two normally distributed covariates. Here, we focus on the scenarios in which both covariates acted as confounders and both treated and untreated subjects were assigned missing covariate values. Results are presented in Table 1. In line with Mitra and Reiter, when we applied PS matching while leaving the outcome variable out of the imputation model, the Across approach outperformed the Within approach in terms of bias (Table 1, scenario 1(a)). With the outcome included in the imputation model (scenario 1(b)), the Within estimates still deviate more from the true treatment effect than the Across estimates, but closely approximate the mean estimate based on PS matching before the introduction of missing values (0.053, 95% CI 0.043; 0.064). The bias observed in the absence of missing data is largely due to non-positivity in the tails of the PS distributions of treated and untreated subjects. As a result, treated subjects in the upper tail of the PS distribution are matched to untreated subjects who tend to have lower PS values, thus leading to suboptimal balance in PS between treated and untreated subjects. This balance can, however, be improved, e.g. by using narrow callipers for matching or increasing the sample size n and thus increasing the number of potential matches. With n increased
Pathfinder networks and author cocitation analysis: A remapping of paradigmatic information scientists

In their 1998 article "Visualizing a discipline: An author cocitation analysis of information science, 1972-1995," White and McCain used multidimensional scaling, hierarchical clustering, and factor analysis to display the specialty groupings of 120 highly-cited ("paradigmatic") information scientists. These statistical techniques are traditional in author cocitation analysis (ACA). It is shown here that a newer technique, Pathfinder Networks (PFNETs), has considerable advantages for ACA. In PFNETs, nodes represent authors, and explicit links represent weighted paths between nodes, the weights in this case being cocitation counts. The links can be drawn to exclude all but the single highest counts for author pairs, which reduces a network of authors to only the most salient relationships. When these are mapped, dominant authors can be defined as those with relatively many links to other authors (i.e., high degree centrality). Links between authors and dominant authors define specialties, and links between dominant authors connect specialties into a discipline. Maps are made with one rather than several computer routines and in one rather than many computer passes. Also, PFNETs can, and should, be generated from matrices of raw counts rather than Pearson correlations, which removes a computational step associated with traditional ACA. White and McCain's raw data from 1998 are remapped as a PFNET. It is shown that the specialty groupings correspond closely to those seen in the factor analysis of the 1998 article. Because PFNETs are fast to compute, they are used in AuthorLink, a new Web-based system that creates live interfaces for cocited author retrieval on the fly.
UDP-galactose 4-epimerase: NAD+ content and a charge-transfer band associated with the substrate-induced conformational transition.

UDP-galactose 4-epimerase from Escherichia coli contains tightly bound NAD+, which participates in catalyzing the interconversion of UDP-galactose and UDP-glucose through its redox properties. The purified enzyme is a dimer of identical subunits that consists of a mixture of catalytically active subunits designated E.NAD+ and inactive, abortive complexes designated E.NADH. uridine nucleotide, in which the uridine nucleotide may be UDP-glucose, UDP-galactose, or UDP [Vanhooke, J. L. , & Frey, P. A. (1994) J. Biol. Chem. 269, 31496-31404]. The abortive complexes are transformed into active E.NAD+ by denaturation of the purified enzyme at 4 degrees C in 6 M guanidine hydrochloride buffered at pH 7.0 in the presence of 0.126 mM NAD+ for 3 h, followed by dilution of guanidine hydrochloride to 0.18 M and of NAD+ to 0.076 mM for 2 h. The renatured enzyme is fully active and contains negligible amounts of NADH and uridine nucleotides. The extinction coefficent of the epimerase at 280 nm is 1.81 +/- 0.15 mL mg-1 cm-1 (epsilon 280 = 137 +/- 11 mM-1 cm-1), as determined by quantitative amino acid analysis and spectrophotometric measurements. This value allows the value of the extinction coefficient for the reduced enzyme (E.NADH)to be calculated as epsilon 344 = 5.7 mM-1 cm-1. On the basis of the new value of epsilon 280, analytical measurements of the nAD+ content of epimerase show that there are two molecules of NAD+ per dimer, which confirms conclusions from X-ray crystallography and revises the earlier bioanalytical determinations. The ultraviolet/visible absorption spectrum of E.NAD+ from denaturation-renaturation experiments reveals the presence of a broad absorption band extending from 300 nm to beyond 360 nm that cannot be attributed to NADH and appears to be a charge-transfer band. This band is partially bleached by UMP and almost totally abolished by UDP, indicating that the interactions leading to the charge-transfer band are altered by the uridine nucleotide-induced conformational change in this enzyme. This conformational change is associated with control of the chemical reactivity of NAD+ in the reaction mechanism.
Factors affecting students attitude toward online shopping

To ensure the success of online business, it is important for the retailers to understand their targeted customers. The aim of this study examines the significance of attitude toward online shopping. The objectives of the study are two fold. The first section seeks to determine relationship between attitude towards online shopping with shopping orientations and perceived benefits scales. The second section investigates factors that influence peoples’ attitudes towards online shopping. A five-level Likert scale was used to determine students’ attitudes towards online shopping. A self-administered questionnaire, based on prior literature, was developed and a total of 370 post graduate students were selected by random sampling. The regression analysis demonstrated the determinants of consumers’ attitudes towards online shopping. Additionally, utilitarian orientations, convenience, price, wider selection influenced consumers’ attitudes towards online shopping. Key words: Electronic commerce, internet, shopping, consumer attitude.
Learning Cost Semantics for Modeling Running Time of OCaml Programs

Programmers would greatly benefit from a source-language model of the running time of compiled code that goes beyond asymptotics. However, it is a difficult problem to accurately model the running time of compiled code at the source level. In this work, we present an operational cost semantics to model the running time of OCaml programs on a specific hardware architecture. Our hypothesis is that the running time of a program can be modeled as a linear function of the number of executions of some high level constructs that we have carefully selected. We learn the coefficients of this linear function by applying traditional machine learning algorithms to automatically adapt the cost semantics to match the measured runtime of training examples on a modern hardware platform. With this learned cost semantics, we are able to model the running time of simple OCaml programs within a reasonable margin of error. Our experiments show that effects of low-level features like memory caches seem to amortize while modeling garbage collection remains a major challenge.
Financial Sector Development and Dollarization in the Economies of Central Asia

This study examines financial dollarization in three economies of Central Asia – Kazakhstan, the Kyrgyz Republic and Tajikistan, where dollarization of bank deposits and loans has remained extensive over the recent years. Different factors are suggested to explain financial dollarization in this region. Deposit dollarization has been a result of memories of economic instability reflected in high rates inflation and depreciating local currencies in the 1990s. Moreover, poor governance and institutions quality together with political instability, poverty and foreign exchange inflows constitute a number of factors that contribute to deposit dollarization. Loan dollarization is highly correlated with deposit dollarization. Furthermore, countries with smaller financial systems have higher dollarization levels. Financial dollarization might pose certain risks to financial stability in case of developed and large financial intermediation. Central Asian economies have thin financial systems but increasing bank assets, and thus close monitoring and effective measures to develop local currency instruments and stability are necessary.
Targeting to Transcriptionally Active Loci by the Hydrophilic N-Terminal Domain of Drosophila DNA Topoisomerase I

ABSTRACT DNA topoisomerase I (topo I) from Drosophila melanogaster contains a nonconserved, hydrophilic N-terminal domain of about 430 residues upstream of the conserved core domains. Deletion of this N terminus did not affect the catalytic activity of topo I, while further removal of sequences into the conserved regions inactivated its enzymatic activity. We have investigated the cellular function of the Drosophila topo I N-terminal domain withtop1-lacZ transgenes. There was at least one putative nuclear localization signal within the first 315 residues of the N-terminal domain that allows efficient import of the large chimeric proteins into Drosophila nuclei. The top1-lacZfusion proteins colocalized with RNA polymerase II (pol II) at developmental puffs on the polytene chromosomes. Either topo I or thetop1-lacZ fusion protein was colocalized with RNA pol II in some but not all of the nonpuff, interband loci. However, the fusion proteins as well as RNA pol II were recruited to heat shock puffs during heat treatment, and they returned to the developmental puffs after recovery from heat shock. By immunoprecipitation, we showed that two of the largest subunits of RNA pol II coprecipitated with the N-terminal 315-residue fusion protein by using antibodies against β-galactosidase. These data suggest that the topo I fusion protein can be localized to the transcriptional complex on chromatin and that the N-terminal 315 residues were sufficient to respond to cellular processes, especially during the reprogramming of gene expression.
Aberrant Development of the Suprachiasmatic Nucleus and Circadian Rhythms in Mice Lacking the Homeodomain Protein Six6

The suprachiasmatic nucleus (SCN) of the mammalian hypothalamus is the central pacemaker for peripheral and organismal circadian rhythms. The development of this hypothalamic structure depends on genetic programs throughout embryogenesis. We have investigated the role of the homeodomain transcription factor Six6 in the development of the SCN. We first showed that Six6 mRNA has circadian regulation in the mouse SCN. We then characterized the behavioral activity patterns of Six6-null mice under various photoperiod manipulations and stained their hypothalami using SCN-specific markers. Six6-null mice display abnormal patterns of circadian behavior indicative of SCN abnormalities. The ability of light exposure to reset rhythms correlates with the presence or absence of optic nerves, but all Six6-null mice show irregular rhythms. In contrast, wild-type mice with crushed optic nerves maintain regular rhythms regardless of light exposure. Using immunohistochemistry for arginine vasopressin (AVP), vasoactive intestinal polypeptide (VIP), and β-galactosidase, we demonstrated the lack of these SCN markers in all Six6-null mice regardless of the presence of optic nerve or partial circadian rhythms. Therefore, Six6 is required for the normal development of the SCN, and the Six6-null mouse can mount independent, although irregular, circadian rhythms despite the apparent absence of a histochemically defined SCN.
Developmental Validation of RSID™‐Semen: A Lateral Flow Immunochromatographic Strip Test for the Forensic Detection of Human Semen *

Abstract: Tests for the identification of semen commonly involve the microscopic visualization of spermatozoa or assays for the presence of seminal markers such as acid phosphatase (AP) or prostate‐specific antigen (PSA). Here, we describe the rapid stain identification kit for the identification of semen (RSID™‐Semen), a lateral flow immunochromatographic strip test that uses two antihuman semenogelin monoclonal antibodies to detect the presence of semenogelin. The RSID™‐Semen strip is specific for human semen, detecting <2.5 nL of semen, and does not cross‐react with other human or nonhuman tissues tested. RSID™‐Semen is more sensitive with certain forensic evidence samples containing mixtures of vaginal secretions and semen than either of the commercially available PSA‐based forensic semen detection tests or tests that measure AP activity that were tested in parallel. The RSID™‐Semen kit also allows sampling a fraction of a questioned stain while retaining the majority of the sample for further processing through short tandem repeat analysis.
Ethnic differences in circadian hemodynamic profile.

Since the introduction of 24-h ambulatory blood pressure monitoring (ABPM), some studies, although not all, have suggested the presence of a blunted nocturnal blood pressure decline in black versus white subjects, a difference that may help explain the higher incidence of target organ damage in blacks. To better define ethnic differences in diurnal hemodynamic profiles, we studied ABPM recordings from 275 black (55.6% women) and 246 white (43.1% women) previously untreated subjects, with a similar age distribution (from 20 to 79 years) and a wide range of systolic (100-230 mm Hg) and diastolic (50-130 mm Hg) blood pressures. Average clinic systolic (diastolic) blood pressures were higher in black v white men by 10.2 (7.3) mm Hg; P = . 04 (P = .004), with a similar trend in women (P = NS). On ABPM, blacks had higher average values, a difference that was greater during sleep (9.4 mm Hg for systolic blood pressure) than while awake (4.7 mm Hg; P = .003). Average diurnal change in systolic blood pressure (awake minus sleep values) was 13.1 +/- 0.7 v 18.0 +/- 0.6 mm Hg for blacks v whites (P < .001). There was a strong negative correlation between baseline (ie, sleep) blood pressure and the diurnal change (r = -0.58; P < .001), but at each given level, blacks had a lower daytime increment/nocturnal fall (P = .02). Results for diastolic blood pressure and heart rate were similar. The data suggest that the smaller diurnal change in blacks may be related in part to their higher blood pressure levels, but that there is an additional, independent effect of race. This results in a greater 24-h blood pressure load in blacks than whites for each given clinic (daytime) value, and may help explain differences in target organ damage. Future studies investigating the effects of blood pressure on target organs in different populations should consider diurnal profiles in addition to clinic blood pressure.
Reduction of mutual coupling between dual-element antennas with new PBG techniques

This paper presents the results of reduction of mutual coupling in closely-packed antennas. The structures include of a simple ground plane and wall that silted pattern etched on a ground plane and the mushroom PBG etched on a wall. It is consequently low cost and simple to fabricate. The isolation of more than -56 dB can be achieved with state-of-the art mushroom PBG loaded on the one wall and with one pair of slit between two parallel microstrip patch antennas; inter-antenna spacing (center to center) is 0.272 λ0. Also we are investigated that with three slits of mushroom PBG on the wall can reduce S12 more than -12 dB. Ground plane size is (0.617 λ0 × 0.376 λ0). In addition the isolation of -37 db can be achieved between two parallel individual planar inverted-F antennas (PIFAs) sharing ground plane and two walls that the mushroom PBG etched on it.
Willingness to Pay in an Open Source Software Environment

Competition from open source software and free software (OSS/FS) alternatives is causing proprietary software producers to reevaluate product strategies. OSS/FS alternatives complicate an already complex information goods market plagued by piracy concerns. Although producer perspectives on software pricing and piracy controls have been addressed extensively, consumers' perspective and willingness to pay for commercial software is not very well understood. This paper empirically determines willingness to pay for a leading commercial software application (Microsoft Office) in the presence of an OSS/FS alternative. A contingent valuation approach is used to elicit willingness to pay for the application. The research design employs a 2 × 2 × 2 experiment to investigate the impact of preventive control, deterrence control, and OSS/FS alternative. The results indicate that the availability of an OSS/FS alternative has little impact on willingness to pay for Microsoft Office. However, piracy controls significantly increase willingness to pay for Microsoft Office, even in the presence of OSS/FS alternatives.
Enzyme polymorphism and the identity of Trypanosoma brucei gambiense

SUMMARY Thirty-two isolates from man in known areas of Gambian trypanosomiasis, in the Sudan, Kenya, Zaire, Nigeria, Ivory Coast, Burkina Faso, Liberia and Senegal, were examined by isoenzyme electrophoresis of 11 enzymes. Comparisons were also made with our previously published results on 23 other stocks of similar origins, which had been examined in the same manner. All those stocks of low initial virulence to laboratory rodents, which thus conform to the accepted view of the behaviour of Trypanosoma brucei gambiense can be identified by characteristic combinations of enzyme patterns, especially certain aminotransferase markers. A limited study of superoxide dismutase polymorphism suggested a further marker of value. The isolates of high initial virulence to rodents, which are thus behaviourally akin to T. b. rhodesiense, did not share these characteristics. We conclude that there exists a homogeneous group of trypanosomes of wide dispersion throughout tropical Africa, characterized by certain isoenzyme combinations and low initial virulence to rodents, which corresponds to the classical concept of T. b. gambiense. The features of limited antigenic repertoire, high resistance to normal human serum and restriction fragment length polymorphisms of the genes for certain variant surface glycoproteins also appear to be characteristic of this group.
Social Housing Investment without Public Finance: The Dutch Case

During the 1990s the Dutch government has reduced its financial support of social housing. the abolition of ‘brick-and-mortar’ subsidies and government loans has left housing associations with the challenge to fully finance their investments with capital-market loans and own resources. This paper discusses how housing associations respond to the diminished government support, focusing in particular on the problems related to the financial ‘mismatch’ of tasks and means between housing associations. Evidence from recent years shows that this problem cannot easily be solved.
Plasminogen activator inhibitor-1 polymorphism is associated with progressive renal dysfunction after acute rejection in renal transplant recipients1

Background. Plasma level of plasminogen activator inhibitor (PAI)-1 is genetically determined by a polymorphism in the promoter region, involving two alleles, 4G and 5G. Plasma PAI-1 concentrations are higher in subjects homozygous for the 4G allele than other genotypes (5G/5G and 4G/5G). Such genetic variation in fibrinolytic system may affect the long-term renal transplant outcome. Methods. We determined PAI-1 4G/5G-promoter genotype polymorphism among our renal transplant recipients between 1985 and 2001. Primary event was defined as doubling of baseline serum-creatinine level. Results. Over a median period of 79 months, 130 patients with 132 kidney grafts were assessed. Baseline clinical variables were comparable among three genotype groups. There was no association between primary event and PAI-1 genotype among the entire cohort. However, among subjects with prior acute rejection episodes, those homozygous for 4G had significantly higher risk of serum creatinine doubling than the other two genotypes (relative risk 2.45, 95% confidence interval 1.19–5.04). PAI-1 genotype does not predict primary events in patients without rejection (relative risk 0.57, 95% confidence interval 0.07–4.17). Conclusions. PAI-1 4G/5G-promoter polymorphism modulates the risk of renal transplant outcomes after acute rejection(s). Recipients homozygous for PAI-1 4G allele have a higher risk of progressive renal damage after acute rejection episode(s). PAI-1 promoter polymorphisms are potentially important determinants of renal response to rejection.
Error-Corrected Reflection and Transmission Scattering Parameters of a Two-Port Device

We present an error correction algorithm for extraction of reflection and transmission scattering (S-) parameters of a two-port device without resorting to a complete two-port calibration. It is shown that S-parameters of thru and nonreflecting line connections in addition to S-parameters of an unknown device (and its reversed orientation) are needed for extracting full S-parameters of the device. For validation, we performed simulations for a chiral metamaterial (transmission asymmetric) and carried out measurements of S-parameters of an asymmetrically loaded waveguide section (reflection asymmetric).
Advertising to Chinese youth: A study of public service ads in Hong Kong

Purpose – Hong Kong youth's general attitudes toward government publicity were studied and their responses to two public service advertisements promoting green lifestyles were measured. The paper aims to discuss these issues.Design/methodology/approach – Thirty‐four Chinese youths in Hong Kong aged 17 to 22 were questioned about their understanding of and attitudes toward public service advertising in face‐to‐face interviews. Their opinions of two government television ads promoting “green living” were then solicited.Findings – The interviewees described government publicity in general as credible and practical. Some liked the green living ads for their creativity but others disliked them as boring, unrealistic, irrelevant and uninformative. Recommendations are presented for designing public service campaigns that target youth.Research limitations/implications – The results were based on a small convenience sample. More than one interviewer participated, so the results were subject to differences in inter.