Accretion disc-corona and jet emission from the radio-loud narrow-line Seyfert 1 galaxy RX J1633.3+4719

We perform X-ray/ultraviolet (UV) spectral and X-ray variability studies of the radio-loud narrow-line Seyfert 1 (NLS1) galaxy RX J1633.3+4719 using XMM-Newton and Suzaku observations from 2011 and 2012. The 0.3-10 keV spectra consist of an ultrasoft component described by an accretion disc blackbody (kT_in = 39.6^{+11.2}_{-5.5} eV) and a power law due to the thermal Comptonization ({\Gamma} = 1.96^{+0.24}_{-0.31}) of the disc emission. The disc temperature inferred from the soft excess is at least a factor of 2 lower than that found for the canonical soft excess emission from radio-quiet NLS1s. The UV spectrum is described by a power law with photon index 3.05^{+0.56}_{-0.33}. The observed UV emission is too strong to arise from the accretion disc or the host galaxy, but can be attributed to a jet. The X-ray emission from RX J1633.3+4719 is variable with fractional variability amplitude $F_{\rm var}$=13.5$\pm1.0$ per cent. In contrast to radio-quiet active galactic nuclei (AGN), X-ray emission from the source becomes harder with increasing flux. The fractional rms variability increases with energy and the rms spectrum is well described by a constant disc component and a variable power-law continuum with the normalization and photon index being anticorrelated. Such spectral variability cannot be caused by variations in the absorption and must be intrinsic to the hot corona. Our finding of possible evidence for emission from the inner accretion disc, jet and hot corona from RX J1633.3+4719 in the optical to X-ray bands makes this object an ideal target to probe the disc-jet connection in AGN.Comment: 12 pages, 11 figures, 3 tables, Published in MNRA

Effects of static electromagnetic fields on sleep patterns: a cross-sectional study

Background: Sleep is an important process of our body and a good sleep will lead to a healthy lifestyle. In medical field, students have sleep patterns changing due to heavy academic workload. This may have ill effects on their health. Though most factors that affect sleep are modifiable and treatment for them exists still there are can be many factors that affect sleep which should be explored. The thermal model of human body is a theoretical model that accounts for thermal effects of electromagnetic waves on a given point in human body. This could be easily affect brain as it has highest electrical activity in body and may lead to sleep related disorders.Methods: This study is conducted on medical and dental students to analyse the amount of electromagnetic field they get exposed to and any changes in sleep patterns associated with it. The findings of medical and dental students are compared to see if changes in sleep patterns are due to professional course pursued. Any other confounding factors affecting this study are screened by self-rated Pacific Sleep Questionnaire.Results: There were significant changes seen in the time taken to fall asleep and total sleep period but the time taken to wake up from sleep remained unaffected. The sleeping habits of medical and dental students showed no significant changes.Conclusions: Static electromagnetic fields have significant impact on sleep onset and sleep duration. This is regardless of academic background

Effect of obesity on cognitive function: a cross-sectional study

Background: Obesity is the leading cause of many health problems. It mostly affects the brain by cerebrovascular events, but since it is a chronic low-grade inflammatory state, inflammatory cytokines in blood alter neuronal function. The jolly-fat hypothesis says that obese people have better cognition as they have more fat storage which is required to make neurotransmitters. Many studies have been done to support each of the above hypotheses but most are done in the paediatric or geriatric populations which can have other confounding factors. Obesity can be easily treated with proper dietary interventions, exercise, pharmaceutical therapies, or surgical interventions. Thus, it was worth exploring as simple lifestyle changes might lower the incidence of cognitive disabilities.Methods: This study was done on undergraduate medical students with a sample size of 120 (60 male and 60 female). Their body mass index was calculated after taking body weight and height. The cognition of subjects was studied using the Washington click reaction time test. This was correlated with body mass index using a t test to find a p value with a level of significance of 0.05.Results: High body mass index is associated with poor cognition as the p<0.05 (0.025006). There was no role of gender on body mass index or cognitive functions.Conclusions: Obesity does affect the cognitive function in healthy adult populations with no comorbidities irrespective of the gender of the individual. More prospective studies with a more sensitive battery of tests can be done to further understand this

Embedded AGN and star formation in the central 80 pc of IC 3639

[Abridged] Methods: We use interferometric observations in the $N$-band with VLTI/MIDI to resolve the mid-IR nucleus of IC 3639. The origin of the nuclear infrared emission is determined from: 1) the comparison of the correlated fluxes from VLTI/MIDI with the fluxes measured at subarcsec resolution (VLT/VISIR, VLT/ISAAC); 2) diagnostics based on IR fine-structure line ratios, the IR continuum emission, IR bands produced by polycyclic aromatic hydrocarbons (PAH) and silicates; and 3) the high-angular resolution spectral energy distribution. Results: The unresolved flux of IC 3639 is $90 \pm 20\, \rm{mJy}$ at $10.5\, \rm{\mu m}$, measured with three different baselines in VLTI (UT1-UT2, UT3-UT4, and UT2-UT3; $46$-$58\, \rm{m}$), making this the faintest measurement so far achieved with mid-IR interferometry. The correlated flux is a factor of $3$-$4$ times fainter than the VLT/VISIR total flux measurement. The observations suggest that most of the mid-IR emission has its origin on spatial scales between $10$ and $80\, \rm{pc}$ ($40$-$340\, \rm{mas}$). A composite scenario where the star formation component dominates over the AGN is favoured by the diagnostics based on ratios of IR fine-structure emission lines, the shape of the IR continuum, and the PAH and silicate bands. Conclusions: A composite AGN-starburst scenario is able to explain both the mid-IR brightness distribution and the IR spectral properties observed in the nucleus of IC 3639. The nuclear starburst would dominate the mid-IR emission and the ionisation of low-excitation lines (e.g. [NeII]$_{12.8 \rm{\mu m}}$) with a net contribution of $\sim 70\%$. The AGN accounts for the remaining $\sim 30\%$ of the mid-IR flux, ascribed to the unresolved component in the MIDI observations, and the ionisation of high-excitation lines (e.g. [NeV]$_{14.3 \rm{\mu m}}$ and [OIV]$_{25.9 \rm{\mu m}}$).Comment: Accepted for publication in A&

Heavy boson production through the collision of an ultrahigh-energy neutrino on a target nucleon

We discuss W and Z production through the deep inelastic neutrino-nucleon scattering in the context of the standard model SU(3)x SU(2)x U(1) of the strong and electroweak interactions. We find the cross section rates for the process neutrino + nucleon --> lepton(-) + W(+) + X for the case of ultrahigh-energy neutrinos colliding on a target nucleon.Comment: 20 pages, 6 figure

Thoracic wall lipoblastoma: a rare case with rare presentation

Lipoblastoma is a rare benign tumor occuring in infancy and early childhood. It is usually located on the extremities but can be found anywhere on the body. Normally, it is well capsulated, but when it is multicentric in origin and diffused in nature it is known as lipoblastomatosis. We report a case of a 1-year-old boy who presented with a huge swelling on the back that, on postoperative histological examination, was diagnosed as lipoblastoma.Keywords: infancy, lipoblastoma, lipoblastomatosi

Thresholded Covering Algorithms for Robust and Max-Min Optimization

The general problem of robust optimization is this: one of several possible scenarios will appear tomorrow, but things are more expensive tomorrow than they are today. What should you anticipatorily buy today, so that the worst-case cost (summed over both days) is minimized? Feige et al. and Khandekar et al. considered the k-robust model where the possible outcomes tomorrow are given by all demand-subsets of size k, and gave algorithms for the set cover problem, and the Steiner tree and facility location problems in this model, respectively. In this paper, we give the following simple and intuitive template for k-robust problems: "having built some anticipatory solution, if there exists a single demand whose augmentation cost is larger than some threshold, augment the anticipatory solution to cover this demand as well, and repeat". In this paper we show that this template gives us improved approximation algorithms for k-robust Steiner tree and set cover, and the first approximation algorithms for k-robust Steiner forest, minimum-cut and multicut. All our approximation ratios (except for multicut) are almost best possible. As a by-product of our techniques, we also get algorithms for max-min problems of the form: "given a covering problem instance, which k of the elements are costliest to cover?".Comment: 24 page

Neutrino Observatories Can Characterize Cosmic Sources and Neutrino Properties

Neutrino telescopes that measure relative fluxes of ultrahigh-energy $\nu_{e}, \nu_{\mu}, \nu_{\tau}$ can give information about the location and characteristics of sources, about neutrino mixing, and can test for neutrino instability and for departures from CPT invariance in the neutrino sector. We investigate consequences of neutrino mixing for the neutrino flux arriving at Earth, and consider how terrestrial measurements can characterize distant sources. We contrast mixtures that arise from neutrino oscillations with those signaling neutrino decays. We stress the importance of measuring $\nu_{e}, \nu_{\mu}, \nu_{\tau}$ fluxes in neutrino observatories.Comment: 9 RevTeX pages, 4 figure

Estimation of Firm-Level Productivity in the Presence of Exports: Evidence from China's Manufacturing

Motivated by the longstanding interest of economists in understanding the nexus between firm productivity and export behavior, this paper develops a novel structural framework for control-function-based nonparametric identification of the gross production function and latent firm productivity in the presence of endogenous export opportunities that is robust to recent unidentification critiques of proxy estimators. We provide a workable identification strategy, whereby the firm's degree of export orientation provides the needed (excluded) relevant independent exogenous variation in endogenous freely varying inputs, thus allowing us to identify the production function. We estimate our fully nonparametric IV model using the Landweber-Fridman regularization with the unknown functions approximated via artificial neural network sieves with a sigmoid activation function which are known for their superior performance relative to other popular sieve approximators, including the polynomial series favored in the literature. Using our methodology, we obtain robust productivity estimates for manufacturing firms from twenty eight industries in China during the 1999-2006 period to take a close look at China's exporter productivity puzzle, whereby exporters are found to exhibit lower productivity levels than non-exports

Expanding hot flow in the black hole binary SWIFT J1753.5-0127: evidence from optical timing

We describe the evolution of optical and X-ray temporal characteristics during the outburst decline of the black hole X-ray binary SWIFT J1753.5-0127. The optical/X-ray cross-correlation function demonstrates a single positive correlation at the outburst peak, then it has multiple dips and peaks during the decline stage, which are then replaced by the precognition dip plus peak structure in the outburst tail. Power spectral densities and phase lags show a complex evolution, revealing the presence of intrinsically connected optical and X-ray quasi-periodic oscillations. For the first time, we quantitatively explain the evolution of these timing properties during the entire outburst within one model, the essence of which is the expansion of the hot accretion flow towards the tail of the outburst. The pivoting of the spectrum produced by synchrotron Comptonization in the hot flow is responsible for the appearance of the anti-correlation with the X-rays and for the optical quasi-periodic oscillations. Our model reproduces well the cross-correlation and phase lag spectrum during the decline stage, which could not be understood with any model proposed before.Comment: 13 pages, 11 figures, MNRAS submitte