Miracle-dz/UniFAR-FTUs huggingface dataset:
A multifrequency analysis of radio variability of blazars

We have carried out a multifrequency analysis of the radio variability of blazars, exploiting the data obtained during the extensive monitoring programs carried out at the University of Michigan Radio Astronomy Observatory (UMRAO, at 4.8, 8, and 14.5 GHz) and at the Metsahovi Radio Observatory (22 and 37 GHz). Two different techniques detect, in the Metsahovi light curves, evidence of periodicity at both frequencies for 5 sources (0224 + 671, 0945 + 408, 1226 + 023, 2200 + 420, and 2251 + 158). For the last three sources, consistent periods are found also at the three UMRAO frequencies and the Scargle (1982) method yields an extremely low false-alarm probability. On the other hand, the 22 and 37 GHz periodicities of 0224+671 and 0945 + 408 (which were less extensively monitored at Metsahovi and for which we get a significant false-alarm probability) are not confirmed by the UMRAO database, where some indications of ill-defined periods of about a factor of two longer are retrieved. We have also investigated the variability index, the structure function, and the distribution of intensity variations of the most extensively monitored sources. We find a statistically significant difference in the distribution of the variability index for BL Lac objects compared to flat-spectrum radio quasars (FSRQs), in the sense that the former objects are more variable. For both populations the variability index steadily increases with increasing frequency. The distribution of intensity variations also broadens with increasing frequency, and approaches a log-normal shape at the highest frequencies. We find that variability enhances by 20-30% the high frequency counts of extragalactic radio-sources at bright flux densities, such as those of the WMAP and PLANCK surveys. In all objects with detected periodicity we find evidence for the existence of impulsive signals superimposed on the periodic component.
Gender Differences in Age-Related Changes in Cardiac Autonomic Nervous Function

Ageing is associated with changes in cardiac autonomic control as measured by Heart Rate Variability (HRV). Not many studies have explored the influence of gender on age-related changes in cardiac autonomic regulation. This study evaluated the gender differences in age-associated changes in cardiac autonomic nervous activity by assessing HRV using frequency domain analysis of short-term stationary R-R intervals. HRV was studied in healthy males and females ranging in age from 6 to 55 years. Total power and absolute power in High-Frequency (HF) and Low-Frequency (LF) components as well as HF in normalized unit declined significantly with ageing. The HF/LF ratio was significantly higher in the adolescent and adult females compared to male of these age groups. This study suggests that gender differences exist in age-related changes in HRV. The finding that gender differences are limited to adolescent and adult age groups may indicate a role for female sex hormones in cardiac autonomic modulation.
THE INFLUENCE OF CONTAINER TYPE AND POTTING MEDIUM ON GROWTH OF BLACK WALNUT SEEDLINGS

Container size and shape, potting medium, and genotype interacted to influence the growth of black walnut (Juglans nigra L.) seedlings. Larger containers tended to produce larger trees. In tall, narrow, vent-pipe containers, different, proportions of peat and sand in potting media had no effect on total weight; a higher proportion of peat than of very fine sand in the potting media reduced the shoot root ratio. In conventionally shaped pots, seedlings averaged 123 percent heavier when grown in a soil mix containing 75 percent peat and 25 percent sand than when grown in pure sand.
The Influence of Dissolution and Precipitation Behavior of M23 (C, B)6 on the Hardenability of Boron Steels

Cu-Ni-Cr-Mo-B low alloy steels whose total B content exceeds a certain limit show superior hardenability when they are austenitized at lower temperatures (≤900°C), although their hardenability decreases with higher austenitizing temperatures and longer holding times. As M23(C, B) 6 in these steels is partly undissolvable at lower austenitizing temperatures, B content in solid solution is not determined uniquely from Fe-B-Al-N equilibrium state but rather regulated by the solubility product of M23(C, B)6. At lower temperatures (≤900°C) B content in solid solution which balances with M23(C, B)6 is considered appropriate for hardenability. At higher temperatures (>900°C), B content in solution which equilibrates with M23(C, B)6 increases and exceeds the limit over which the hardenability of B steels decreases. Heating below Ac1 for a long period, while M23(C, B)6 is enriched with C, Mn and Mo atoms, austenitizing condition appropriate for the hardenability is transferred to higher temperatures and longer periods. This is because the solubility product of M23(C, B)6 is lessened and the particles grow coarser.Boron content in solid solution which balances with M23(C, B) 6 is determined approximately from the relation among the decrease of hardenability, quenching temperature, and B content in solution calculated from the Fe-Al-B-N system. The result is as follows: 880°C-3ppm, 900°C-6ppm and 930°C-8ppm.These values are considered to depend strongly on Cr, Mn and Mo contents and prior heat treating history. In excess-B-containing steels, “Boron Constituents” are observed on the prior austenite grain boundaries at distances longer than 15mm from the quenched end of Jominy end quench test specimens, when they are quenched from 930°C.
Self-concordant analysis for logistic regression

Most of the non-asymptotic theoretical work in regression is carried out for the square loss, where estimators can be obtained through closed-form expressions. In this paper, we use and extend tools from the convex optimization literature, namely self-concordant functions, to provide simple extensions of theoretical results for the square loss to the logistic loss. We apply the extension techniques to logistic regression with regularization by the $\ell_2$-norm and regularization by the $\ell_1$-norm, showing that new results for binary classification through logistic regression can be easily derived from corresponding results for least-squares regression.
ICT-supported pedagogical policies and practices in South Africa and Chile: emerging economies and realities

South Africa participated in all three of the Second International Technology in Education Study (SITES). In the first international study, South Africa was the only developing country, and therefore, stark contrasts were found in the international study between South Africa and the other participating countries. Chile participated in the SITES 2006 as one of a few developing countries making the comparison with South Africa possible. Despite similarities in their contexts and economies, their approach to information and communication technologies (ICTs) in education appears to differ. This difference raised questions about differences in policies and their implementation at school level. This research conducted in South Africa found that the Chilean strategy for developing and implementing their ICT in education appear to be very different with regard to its design, the organization, the strategies adopted, the resources used and, most importantly, their approach to teacher development for implementing ICT. A number of lessons are revealed for the South African policymakers and others from similar developing contexts.
Giving up on child psychotherapy: who drops out?

Do dropouts from child psychotherapy differ from those who stay for treatment? To find out, we studied 6-17-year-old outpatients, 166 who completed intake but did not appear for therapy and 138 who continued in therapy for an average of 13 sessions. The groups were compared on demographics, on Child Behavior Checklist broadband and narrow-band syndrome scores, on Children's Depression Inventory scores, on therapist age and sex, and on parent perceptions of clinic and child. No reliable group differences were found. The striking group similarity may have implications for clinic-based outcome research.
Protection of Bacillus pumilus Spores by Catalases

ABSTRACT Bacillus pumilus SAFR-032, isolated at spacecraft assembly facilities of the National Aeronautics and Space Administration Jet Propulsion Laboratory, is difficult to kill by the sterilization method of choice, which uses liquid or vapor hydrogen peroxide. We identified two manganese catalases, YjqC and BPUM_1305, in spore protein extracts of several B. pumilus strains by using PAGE and mass spectrometric analyses. While the BPUM_1305 catalase was present in six of the B. pumilus strains tested, YjqC was not detected in ATCC 7061 and BG-B79. Furthermore, both catalases were localized in the spore coat layer along with laccase and superoxide dismutase. Although the initial catalase activity in ATCC 7061 spores was higher, it was less stable over time than the SAFR-032 enzyme. We propose that synergistic activity of YjqC and BPUM_1305, along with other coat oxidoreductases, contributes to the enhanced resistance of B. pumilus spores to hydrogen peroxide. We observed that the product of the catalase reaction, gaseous oxygen, forms expanding vesicles on the spore surface, affecting the mechanical integrity of the coat layer, resulting in aggregation of the spores. The accumulation of oxygen gas and aggregations may play a crucial role in limiting further exposure of Bacilli spore surfaces to hydrogen peroxide or other toxic chemicals when water is present.
Purification and Structural Characterization of Siderophore (Corynebactin) from Corynebacterium diphtheriae

During infection, Corynebacterium diphtheriae must compete with host iron-sequestering mechanisms for iron. C. diphtheriae can acquire iron by a siderophore-dependent iron-uptake pathway, by uptake and degradation of heme, or both. Previous studies showed that production of siderophore (corynebactin) by C. diphtheriae is repressed under high-iron growth conditions by the iron-activated diphtheria toxin repressor (DtxR) and that partially purified corynebactin fails to react in chemical assays for catecholate or hydroxamate compounds. In this study, we purified corynebactin from supernatants of low-iron cultures of the siderophore-overproducing, DtxR-negative mutant strain C. diphtheriae C7(β) ΔdtxR by sequential anion-exchange chromatography on AG1-X2 and Source 15Q resins, followed by reverse-phase high-performance liquid chromatography (RP-HPLC) on Zorbax C8 resin. The Chrome Azurol S (CAS) chemical assay for siderophores was used to detect and measure corynebactin during purification, and the biological activity of purified corynebactin was shown by its ability to promote growth and iron uptake in siderophore-deficient mutant strains of C. diphtheriae under iron-limiting conditions. Mass spectrometry and NMR analysis demonstrated that corynebactin has a novel structure, consisting of a central lysine residue linked through its α- and ε- amino groups by amide bonds to the terminal carboxyl groups of two different citrate residues. Corynebactin from C. diphtheriae is structurally related to staphyloferrin A from Staphylococcus aureus and rhizoferrin from Rhizopus microsporus in which d-ornithine or 1,4-diaminobutane, respectively, replaces the central lysine residue that is present in corynebactin.
Joint Transmission and State Estimation: A Constrained Channel Coding Approach

A scenario involving a source, a channel, and a destination, where the destination is interested in both reliably reconstructing the message transmitted by the source and estimating with a fidelity criterion the state of the channel, is considered. The source knows the channel statistics but is oblivious to the actual channel state realization. Herein, it is established that a distortion constraint for channel state estimation can be reduced to an additional cost constraint on the source input distribution, in the limit of large coding block length. A newly defined capacity-distortion function thus characterizes the fundamental tradeoff between transmission rate and state estimation distortion. It is also shown that noncoherent communication coupled with channel state estimation conditioned on treating the decoded message as training symbols achieves the capacity-distortion function. Among the various examples considered, the capacity-distortion function for a memoryless Rayleigh fading channel is characterized to within 1.443 bits at high signal-to-noise ratio. The constrained channel coding approach is also extended to multiple access channels, leading to a coupled cost constraint on the input distributions for the transmitting sources.
A short note on the taeuber paradox

When the force of mortality is reduced by a constant fraction 0 at every age, the relative increase in life expectancy e(0) can be measured by δH, where H is determined by the l(a) values of the life table. Although H is not easily reducible in terms of the well-known life table parameters, it has been shown that it can be approximately estimated by 2 – e(0)/à in which d is the average age of the stationary population. It has been found that, for a given value of 0, the relative gain in life expectancy is less appreciable in countries with larger values of e(0).
Genetics and genomics of ovarian sex cord‐stromal tumors

Ovarian sex cord‐stromal tumors (SCST) represent approximately 8% of malignant ovarian tumors. The most common are granulosa cell tumors (GCT) which account for approximately 90% of malignant SCST. Recent studies have unraveled the key genomic and genetic events contributing to their pathogenesis. SCST are found in the hereditary syndromes: Peutz‐Jeghers syndrome, Ollier disease and Maffucci syndrome, and DICER1 syndrome. Genomic studies have largely been limited to GCT where a number of recurring chromosomal abnormalities (monsomy and trisomy) have been identified although their contribution to pathogenesis remains unclear. In addition to the recurrent DICER1 mutations reported in non‐hereditary cases of Sertoli cell and Sertoli–Leydig cell tumors, recurrent somatic mutations in both the juvenile (j) and adult (a) forms of GCT have been reported. Approximately 30% of jGCT contain a somatic mutation, the gsp oncogene, while a further 60% have an activating mutation in the AKT gene. In the case of aGCT, a well characterized mutation in the FOXL2 transcription factor (FOXL2 C134W) is found in almost all cases, which arguably defines the disease, although the molecular events that determine the stage, behavior and prognosis of aGCT remain to be determined.
Martingale characterizations of coherent acceptability measures

The coherent risk framework is linked to martingale valuation by adding hedgeinvariance as a fifth axiom, motivated by the concept of consistent hedging. The resulting subclass, called coherent pre-hedge (CoPr) measures, is characterized by a martingale condition on the test set that underlies a coherent measure. It is also made explicit how consistent hedging, optimal as well as non-optimal, transforms the test set of a given coherent measure into a martingale test set. These results are put in perspective of the fundamental theorems of asset pricing and the concept of valuation bounds.
Are overweight children unhappy?: Body mass index, depressive symptoms, and overweight concerns in elementary school children.

BACKGROUND It is commonly believed that overweight children are unhappy with their weight. However, population-based data addressing this association are lacking. OBJECTIVES To evaluate the association between obesity and depressive symptoms in a diverse, school-based sample of preadolescent children, and to examine whether overweight concerns play a role in this association. DESIGN, SETTING, AND PARTICIPANTS Third-grade students (N = 868, mean age, 8.4 years) attending 13 public elementary schools in Northern California were measured for weight and height, and were asked to complete self-report assessments of depressive symptoms and overweight concerns. RESULTS A modest association between depressive symptoms and body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters) was found for girls (r = 0.14, P<.01), but not for boys (r = 0.01, P<.78). Among girls, depressive symptoms were strongly associated with overweight concerns (r = 0.32, P<.001). After controlling for level of overweight concerns, BMI was no longer significantly associated with depressive symptoms among girls. In contrast, after controlling for BMI, overweight concerns remained significantly associated with depressive symptoms. CONCLUSIONS This study provides cross-sectional evidence for a relationship between depressive symptoms and BMI in preadolescent girls, but not in preadolescent boys. This relationship seems to be explained by an excess of overweight concerns. Assessing overweight concerns may be a useful method to identify those overweight girls who are at highest risk for associated depressive symptoms.
Studies on properties of banana fiber reinforced green composite

India contributes a large percentage to total world production of rice husk, jute, banana, and coconut fiber. All these natural fibers have excellent physical and mechanical properties, which can be used effectively in the development of composite materials for various structural applications. This article gives an overall view of banana fiber composite and its mechanical properties. The advantage of using natural fiber materials over traditional materials and its possible growth in future are also discussed. The experimental results showed that 15 wt% banana fiber reinforced composite show optimum mechanical properties.
Measuring Convergence and Priming in Tutorial Dialog

Experimental research has shown that human users will converge with dialog systems along many dimensions of speech, including those of acoustic/prosodic features and lexical choice. Other results suggest that speech convergence may provide a variety of benefits to spoken dialog systems, such as an improved user model, increased ease of use, improved feelings of intimacy, and increased compliance on the part of the user. These potential benefits to dialog systems of generating or detecting convergence behaviors suggest the need for corpus studies of convergence, in addition to the experimental results. Here, we build on previous work to demonstrate corpus measures of lexical and acoustic/prosodic convergence. We show that these measures successfully distinguish randomized from naturally ordered data, and demonstrate both lexical and acoustic/prosodic priming effects in our corpus of human/human tutoring dialogs.
A NEW ASYMPTOTIC THEORY FOR HETEROSKEDASTICITY-AUTOCORRELATION ROBUST TESTS

A new first-order asymptotic theory for heteroskedasticity-autocorrelation (HAC) robust tests based on nonparametric covariance matrix estimators is developed. The bandwidth of the covariance matrix estimator is modeled as a fixed proportion of the sample size. This leads to a distribution theory for HAC robust tests that explicitly captures the choice of bandwidth and kernel. This contrasts with the traditional asymptotics (where the bandwidth increases more slowly than the sample size) where the asymptotic distributions of HAC robust tests do not depend on the bandwidth or kernel. Finite-sample simulations show that the new approach is more accurate than the traditional asymptotics. The impact of bandwidth and kernel choice on size and power of t-tests is analyzed. Smaller bandwidths lead to tests with higher power but greater size distortions, and large bandwidths lead to tests with lower power but smaller size distortions. Size distortions across bandwidths increase as the serial correlation in the data becomes stronger. Overall, the results clearly indicate that for bandwidth and kernel choice there is a trade-off between size distortions and power. Finite-sample performance using the new asymptotics is comparable to the bootstrap, which suggests that the asymptotic theory in this paper could be useful in understanding the theoretical properties of the bootstrap when applied to HAC robust tests.We thank an editor and a referee for constructive comments on a previous version of the paper. Helpful comments provided by Cliff Hurvich, Andy Levin, Jeff Simonoff, and seminar participants at NYU (Statistics), U. Texas Austin, Yale, U. Montreal, UCSD, UC Riverside, UC Berkeley, U. of Pittsburgh, SUNY Albany, U. Aarhus, Brown U. , NBER/NSF Time Series Conference, and 2003 Winter Meetings of the Econometrics Society are gratefully acknowledged. We gratefully acknowledge financial support from the National Science Foundation through grant SES-0095211. We thank the Center for Analytic Economics at Cornell University.
Snapshot of a key intermediate in enzymatic thiamin catalysis: Crystal structure of the α-carbanion of (α,β-dihydroxyethyl)-thiamin diphosphate in the active site of transketolase from Saccharomyces cerevisiae

Kinetic and spectroscopic data indicated that addition of the donor substrate hydroxypyruvate to the thiamin diphosphate (ThDP)-dependent enzyme transketolase (TK) led to the accumulation of the α-carbanion/enamine of (α,β-dihydroxyethyl) ThDP, the key reaction intermediate in enzymatic thiamin catalysis. The three-dimensional structure of this intermediate trapped in the active site of yeast TK was determined to 1.9-Å resolution by using cryocrystallography. The electron density suggests a planar α-carbanion/enamine intermediate having the E-configuration. The reaction intermediate is firmly held in place through direct hydrogen bonds to His-103 and His-481 and an indirect hydrogen bond via a water molecule to His-69. The 4-NH2 group of the amino-pyrimidine ring of ThDP is within 3 Å distance to the α-hydroxy oxygen atom of the dihydroxyethyl moiety but at an angle unfavorable for a strong hydrogen bond. No structural changes occur in TK on formation of the reaction intermediate, suggesting that the active site is poised for catalysis and conformational changes during the enzyme reaction are not very likely. The intermediate is present with high occupancy in both active sites, arguing against previous proposals of half-of-the-sites reactivity in yeast TK.
Mamao Pomace Extract Alleviates Hypertension and Oxidative Stress in Nitric Oxide Deficient Rats

Reactive oxygen species (ROS)-induced oxidative stress plays a major role in pathogenesis of hypertension. Antidesma thwaitesianum (local name: Mamao) is a tropical plant distributed in the tropical/subtropical areas of the world, including Thailand. Mamao pomace (MP), a by-product generated from Mamao fruits, contains large amounts of antioxidant polyphenolic compounds. The aim of this study was to investigate the antihypertensive and antioxidative effects of MP using hypertensive rats. For this purpose, male Sprague-Dawley rats were given Nω-nitro-l-arginine methyl ester (l-NAME), an inhibitor of endothelial nitric oxide synthase (eNOS), in drinking water (50 mg/kg) for three weeks. MP extract was orally administered daily at doses of 100 and 300 mg/kg. l-NAME administration induced marked increase in blood pressure, peripheral vascular resistance, and oxidative stress. MP treatment significantly prevented the increase in blood pressure, hindlimb blood flow and hindlimb vascular resistance of l-NAME treated hypertensive rats (p < 0.05). The antihypertensive effect of MP treatment was associated with suppression of superoxide production from carotid strips and also with an increase in eNOS protein expression and nitric oxide bioavailability. The present results provide evidence for the antihypertensive effect of MP and suggest that MP might be useful as a dietary supplement against hypertension.