bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changing Trend of Instrumental Vaginal Deliveries at Patan Hospital
Authors: Lamichhane B , Singh A 
Published: January 2016

Aims: The aim of the study was to evaluate the changing trend of the instrumental vaginal deliveries at Patan hospital over the last 10 years.Methods: This was a retrospective study done at Patan hospital. The study included data of 10 years duration (July 15th, 2004 – July 14th, 2014). The data included total normal delivery, caesarean section, vacuum delivery, forceps delivery and total delivery of the respective years.Results: Out of 80,149 deliveries over 10 years, 1635 (2.03%) were instrumental vaginal delivery (IVD). The study revealed progressive decline in overall trend of instrumental vaginal delivery. The highest percentage of IVD in the year 2005 was 265 (16.02%) and tangential dropped to 49 (2.9%) by 2014. The study revealed markedly decreased trend in vacuum delivery from 2005 to 2010, but a positive deflection was noticed till 2013, and abrupt fall in the year 2014.Regarding forceps delivery, a gradual fall in trend was noticed over the years. Over the last 10 years the mean percentile value of vacuum delivery was 78.47% while that of forceps was 21.52 %.Conclusions: The trend of instrumental vaginal delivery has markedly declined. On the other hand, it has shown increasing trend in caesarean delivery.
Outcome of Medical versus Surgical Methods in Second Trimester Abortion
Authors: Lama S , Chherty S 
Published: January 2016

Aims: This study aimed to assess the effectiveness of medical versus the surgical methods and to determine the outcome of both the methods with respect to complications like incomplete abortion, bleeding and sepsis.Methods: This study was conducted at BP Koirala Institue of Health Sciences. Total of 80 patients, 40 in each group were enrolled in the study. For medical abortion group, Mifepristone 200mg orally followed by Misoprostol 400 mcg vaginally were given until the patient expelled the fetus. In surgical group, cervical priming was done with Misoprostol followed by dilatation and evacuation. The outcome of both medical and surgical abortions were compared in terms of amount of blood loss and associated complications like retained placenta and sepsis.Results: The overall complications were more in the medical group with 11.25% vs 2.5% in the surgical group (p value=0.02), with higher incidence of retained placenta (8 vs 0) and a higher amount of blood loss (129.20 +/- 20.4 ml vs 70.89 +/- 11.2 ml, p value <0.001) requiring blood transfusion.Conclusions: This study demonstrated that the surgical method is a more effective and safer procedure as compared to medical method. The complication rates were lower and it was also more cost effective.
REVEALING W51C AS A COSMIC RAY SOURCE USING FERMI-LAT DATA
Authors: Jogler T. , Funk S. 
Published: January 2016

ABSTRACT
Supernova remnants (SNRs) are commonly believed to be the primary sources of Galactic cosmic rays. Despite intensive study of the non-thermal emission of many SNRs the identification of the accelerated particle type relies heavily on assumptions of ambient-medium parameters that are only loosely constrained. Compelling evidence of hadronic acceleration can be provided by detecting a strong roll-off in the secondary γ-ray spectrum below the

production threshold energy of about 135 MeV, the so called “pion bump.” Here we use five years of Fermi-Large Area Telescope data to study the spectrum above 60 MeV of the middle-aged SNR W51C. A clear break in the power-law γ-ray spectrum at

is detected with

significance and we show that this break is most likely associated with the energy production threshold of

mesons. A high-energy break in the γ-ray spectrum at about 2.7 GeV is found with

significance. The spectral index at energies beyond this second break is

and closely matches the spectral index derived by the MAGIC Collaboration above 75 GeV. Therefore our analysis provides strong evidence to explain the γ-ray spectrum of W51C by a single particle population of protons with a momentum spectrum best described by a broken power law with break momentum

W51C is the third middle-aged SNR that displays compelling evidence for cosmic-ray acceleration and thus strengthens the case of SNRs as the main source of Galactic cosmic rays.
WHISTLER TURBULENCE HEATING OF ELECTRONS AND IONS: THREE-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS
Authors: Gary S. Peter , Hughes R. Scott , Wang Joseph 
Published: January 2016

ABSTRACT
The decay of whistler turbulence in a collisionless, homogeneous, magnetized plasma is studied using three-dimensional particle-in-cell simulations. The simulations are initialized with a narrowband, relatively isotropic distribution of long wavelength whistler modes. A first ensemble of simulations at electron beta

= 0.25 and ion-to-electron mass ratio

/

= 400 is carried out on a domain cube of dimension

/c = 5.12 where

is the ion plasma frequency. The simulations begin with a range of dimensionless fluctuating field energy densities,

, and follow the fluctuations as they cascade to broadband, anisotropic turbulence which dissipates at shorter wavelengths, heating both electrons and ions. The electron heating is stronger and preferentially parallel/antiparallel to the background magnetic field

the ion energy gain is weaker and is preferentially in directions perpendicular to

. The important new results here are that, over 0.01 <

< 0.25, the maximum rate of electron heating scales approximately as

, and the maximum rate of ion heating scales approximately as

. A second ensemble of simulations at

= 0.10 and

= 0.25 shows that, over 25 <

/

< 1836, the ratio of the maximum ion heating rate to the maximum electron heating rate scales approximately as

/

.
SYNCHROTRON ORIGIN OF THE TYPICAL GRB BAND FUNCTION—A CASE STUDY OF GRB 130606B
Authors: Zhang Bin-Bin , Uhm Z. Lucas , Connaughton Valerie , Briggs Michael S. , Zhang Bing 
Published: January 2016

ABSTRACT
We perform a time-resolved spectral analysis of GRB 130606B within the framework of a fast-cooling synchrotron radiation model with magnetic field strength in the emission region decaying with time, as proposed by Uhm & Zhang. The data from all time intervals can be successfully fit by the model. The same data can be equally well fit by the empirical Band function with typical parameter values. Our results, which involve only minimal physical assumptions, offer one natural solution to the origin of the observed GRB spectra and imply that, at least some, if not all, Band-like GRB spectra with typical Band parameter values can indeed be explained by synchrotron radiation.
RELATIVE CONTRIBUTIONS OF THE WEAK, MAIN, AND FISSION-RECYCLING r-PROCESS
Authors: Shibagaki S. , Kajino T. , Mathews G. J. , Chiba S. , Nishimura S. , Lorusso G. 
Published: January 2016

ABSTRACT
There has been a persistent conundrum in attempts to model the nucleosynthesis of heavy elements by rapid neutron capture (the r-process). Although the locations of the abundance peaks near nuclear mass numbers 130 and 195 identify an environment of rapid neutron capture near closed nuclear shells, the abundances of elements just above and below those peaks are often underproduced by more than an order of magnitude in model calculations. At the same time, there is a debate in the literature as to what degree the r-process elements are produced in supernovae or the mergers of binary neutron stars. In this paper we propose a novel solution to both problems. We demonstrate that the underproduction of nuclides above and below the r-process peaks in main or weak r-process models (like magnetohydrodynamic jets or neutrino-driven winds in core-collapse supernovae) can be supplemented via fission fragment distributions from the recycling of material in a neutron-rich environment such as that encountered in neutron star mergers (NSMs). In this paradigm, the abundance peaks themselves are well reproduced by a moderately neutron-rich, main r-process environment such as that encountered in the magnetohydrodynamical jets in supernovae supplemented with a high-entropy, weakly neutron-rich environment such as that encountered in the neutrino-driven-wind model to produce the lighter r-process isotopes. Moreover, we show that the relative contributions to the r-process abundances in both the solar system and metal-poor stars from the weak, main, and fission-recycling environments required by this proposal are consistent with estimates of the relative Galactic event rates of core-collapse supernovae for the weak and main r-process and NSMs for the fission-recycling r-process.
SENSITIVE 21 cm OBSERVATIONS OF NEUTRAL HYDROGEN IN THE LOCAL GROUP NEAR M31
Authors: Wolfe Spencer A. , Lockman Felix J. , Pisano D. J. 
Published: January 2016

ABSTRACT
Very sensitive 21 cm H i measurements have been made at several locations around the Local Group galaxy M31 using the Green Bank Telescope at an angular resolution of 9.′1, with a 5σ detection level of N
H i
= 3.9 × 1017 cm−2 for a 30 km s−1 line. Most of the H i in a 12 square-degree area almost equidistant between M31 and M33 is contained in nine discrete clouds that have a typical size of a few kpc and a H i mass of 105
M
⊙. Their velocities in the Local Group Standard of Rest lie between −100 and +40 km s−1, comparable to the systemic velocities of M31 and M33. The clouds appear to be isolated kinematically and spatially from each other. The total H i mass of all nine clouds is 1.4 × 106
M
⊙ for an adopted distance of 800 kpc, with perhaps another 0.2 × 106
M
⊙ in smaller clouds or more diffuse emission. The H i mass of each cloud is typically three orders of magnitude less than the dynamical (virial) mass needed to bind the cloud gravitationally. Although they have the size and H i mass of dwarf galaxies, the clouds are unlikely to be part of the satellite system of the Local Group, as they lack stars. To the north of M31, sensitive H i measurements on a coarse grid find emission that may be associated with an extension of the M31 high-velocity cloud (HVC) population to projected distances of ∼100 kpc. An extension of the M31 HVC population at a similar distance to the southeast, toward M33, is not observed.
CONTINUUM ENHANCEMENTS IN THE ULTRAVIOLET, THE VISIBLE AND THE INFRARED DURING THE X1 FLARE ON 2014 MARCH 29
Authors: Kleint Lucia , Heinzel Petr , Judge Phil , Krucker Säm 
Published: January 2016

ABSTRACT
Enhanced continuum brightness is observed in many flares (“white light flares”), yet it is still unclear which processes contribute to the emission. To understand the transport of energy needed to account for this emission, we must first identify both the emission processes and the emission source regions. Possibilities include heating in the chromosphere causing optically thin or thick emission from free-bound transitions of Hydrogen, and heating of the photosphere causing enhanced H− continuum brightness. To investigate these possibilities, we combine observations from Interface Region Imaging Spectrograph (IRIS), SDO/Helioseismic and Magnetic Imager, and the ground-based Facility Infrared Spectrometer instrument, covering wavelengths in the far-UV, near-UV (NUV), visible, and infrared during the X1 flare SOL20140329T17:48. Fits of blackbody spectra to infrared and visible wavelengths are reasonable, yielding radiation temperatures ∼6000–6300 K. The NUV emission, formed in the upper photosphere under undisturbed conditions, exceeds these simple fits during the flare, requiring extra emission from the Balmer continuum in the chromosphere. Thus, the continuum originates from enhanced radiation from photosphere (visible-IR) and chromosphere (NUV). From the standard thick-target flare model, we calculate the energy of the nonthermal electrons observed by Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) and compare it to the energy radiated by the continuum emission. We find that the energy contained in most electrons >40 keV, or alternatively, of ∼10%–20% of electrons >20 keV is sufficient to explain the extra continuum emission of ∼(4–8) × 1010 erg s−1 cm−2. Also, from the timing of the RHESSI HXR and the IRIS observations, we conclude that the NUV continuum is emitted nearly instantaneously when HXR emission is observed with a time difference of no more than 15 s.
CHROMOSPHERIC SUNSPOTS IN THE MILLIMETER RANGE AS OBSERVED BY THE NOBEYAMA RADIOHELIOGRAPH
Authors: Iwai Kazumasa , Koshiishi Hideki , Shibasaki Kiyoto , Nozawa Satoshi , Miyawaki Shun , Yoneya Takuro 
Published: January 2016

ABSTRACT
We investigate the upper chromosphere and the transition region of the sunspot umbra using the radio brightness temperature at 34 GHz (corresponding to 8.8 mm observations) as observed by the Nobeyama Radioheliograph (NoRH). Radio free–free emission in the longer millimeter range is generated around the transition region, and its brightness temperature yields the region's temperature and density distribution. We use the NoRH data at 34 GHz by applying the Steer-CLEAN image synthesis. These data and the analysis method enable us to investigate the chromospheric structures in the longer millimeter range with high spatial resolution and sufficient visibilities. We also perform simultaneous observations of one sunspot using the NoRH and the Nobeyama 45 m telescope operating at 115 GHz. We determine that 115 GHz emission mainly originates from the lower chromosphere while 34 GHz emission mainly originates from the upper chromosphere and transition region. These observational results are consistent with the radio emission characteristics estimated from current atmospheric models of the chromosphere. On the other hand, the observed brightness temperature of the umbral region is almost the same as that of the quiet region. This result is inconsistent with current sunspot models, which predict a considerably higher brightness temperature of the sunspot umbra at 34 GHz. This inconsistency suggests that the temperature of the region at which the 34 GHz radio emission becomes optically thick should be lower than that predicted by the models.
TRANSITION-REGION/CORONAL SIGNATURES AND MAGNETIC SETTING OF SUNSPOT PENUMBRAL JETS: HINODE (SOT/FG), Hi-C, AND SDO/AIA OBSERVATIONS
Authors: Tiwari Sanjiv K. , Moore Ronald L. , Winebarger Amy R. , Alpert Shane E. 
Published: January 2016

ABSTRACT
Penumbral microjets (PJs) are transient narrow bright features in the chromosphere of sunspot penumbrae, first characterized by Katsukawa et al. using the Ca ii H-line filter on Hinode's Solar Optical Telescope (SOT). It was proposed that the PJs form as a result of reconnection between two magnetic components of penumbrae (spines and interspines), and that they could contribute to the transition region (TR) and coronal heating above sunspot penumbrae. We propose a modified picture of formation of PJs based on recent results on the internal structure of sunspot penumbral filaments. Using data of a sunspot from Hinode/SOT, High Resolution Coronal Imager, and different passbands of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we examine whether PJs have signatures in the TR and corona. We find hardly any discernible signature of normal PJs in any AIA passbands, except for a few of them showing up in the 1600 Å images. However, we discovered exceptionally stronger jets with similar lifetimes but bigger sizes (up to 600 km wide) occurring repeatedly in a few locations in the penumbra, where evidence of patches of opposite-polarity fields in the tails of some penumbral filaments is seen in Stokes-V images. These tail PJs do display signatures in the TR. Whether they have any coronal-temperature plasma is unclear. We infer that none of the PJs, including the tail PJs, directly heat the corona in active regions significantly, but any penumbral jet might drive some coronal heating indirectly via the generation of Alfvén waves and/or braiding of the coronal field.
DROPOUT OF DIRECTIONAL ELECTRON INTENSITIES IN LARGE SOLAR ENERGETIC PARTICLE EVENTS
Authors: Tan Lun C. , Reames Donald V. 
Published: January 2016

ABSTRACT
In the “gradual” solar energetic particle (SEP) event during solar cycle 23 we have observed the dispersionless modulation (“dropout”) in directional intensities of nonrelativistic electrons. The average duration of dropout periods is ∼0.8 hr, which is consistent with the correlation scale of solar wind turbulence. During the dropout period electrons could display scatter-free transport in an intermittent way. Also, we have observed a decrease in the anisotropic index of incident electrons with increasing electron energy (E
e), while the index of scattered/reflected electrons is nearly independent of E
e. We hence perform an observational examination of the correlation between the anisotropic index of low-energy scattered/reflected electrons and the signature of the locally measured solar wind turbulence in the dissipation range, which is responsible for resonant scattering of nonrelativistic electrons. Since during the dropout period the slab turbulence fraction is dominant (0.8 ± 0.1), we pay close attention to the effect of slab fraction on the correlation examined. Our observation is consistent with the simulation result that in the dominance of the slab turbulence component there should exist a dispatched structure of magnetic flux tubes, along which electrons could be transported in a scatter-free manner. Since a similar phenomenon is exhibited in the “impulsive” SEP event, electron dropout should be a transport effect. Therefore, being different from most ion dropout events, which are due to a compact flare source, the dropout of directional electron intensities should be caused by the change of turbulence status in the solar wind.
DYNAMICAL CONSIDERATIONS FOR LIFE IN MULTI-HABITABLE PLANETARY SYSTEMS
Authors: Steffen Jason H. , Li Gongjie 
Published: January 2016

ABSTRACT
Inspired by the close-proximity pair of planets in the Kepler-36 system, we consider two effects that may have important ramifications for the development of life in similar systems where a pair of planets may reside entirely in the habitable zone of the hosting star. Specifically, we run numerical simulations to determine whether strong, resonant (or non-resonant) planet–planet interactions can cause large variations in planet obliquity—thereby inducing large variations in climate. We also determine whether or not resonant interactions affect the rate of lithopanspermia between the planet pair—which could facilitate the growth and maintenance of life on both planets. We find that first-order resonances do not cause larger obliquity variations when compared with non-resonant cases. We also find that these resonant interactions are not a primary consideration in lithopanspermia. Lithopanspermia is enhanced significantly as the planet orbits come closer together—reaching nearly the same rate as ejected material falling back to the surface of the originating planet (assuming that the ejected material makes it out to the location of our initial conditions). Thus, in both cases our results indicate that close-proximity planet pairs in multi-habitable systems are conducive to life in the system.
MERGER SIGNATURES IN THE DYNAMICS OF STAR-FORMING GAS
Authors: Hung (洪肇伶) Chao-Ling , Hayward Christopher C. , Smith Howard A. , Ashby Matthew L. N. , Lanz Lauranne , Martínez-Galarza Juan R. , Sanders D. B. , Zezas Andreas 
Published: January 2016

ABSTRACT
The recent advent of integral field spectrographs and millimeter interferometers has revealed the internal dynamics of many hundreds of star-forming galaxies. Spatially resolved kinematics have been used to determine the dynamical status of star-forming galaxies with ambiguous morphologies, and constrain the importance of galaxy interactions during the assembly of galaxies. However, measuring the importance of interactions or galaxy merger rates requires knowledge of the systematics in kinematic diagnostics and the visible time with merger indicators. We analyze the dynamics of star-forming gas in a set of binary merger hydrodynamic simulations with stellar mass ratios of 1:1 and 1:4. We find that the evolution of kinematic asymmetries traced by star-forming gas mirrors morphological asymmetries derived from mock optical images, in which both merger indicators show the largest deviation from isolated disks during strong interaction phases. Based on a series of simulations with various initial disk orientations, orbital parameters, gas fractions, and mass ratios, we find that the merger signatures are visible for ∼0.2–0.4 Gyr with kinematic merger indicators but can be approximately twice as long for equal-mass mergers of massive gas-rich disk galaxies designed to be analogs of z ∼ 2–3 submillimeter galaxies. Merger signatures are most apparent after the second passage and before the black holes coalescence, but in some cases they persist up to several hundred Myr after coalescence. About 20%–60% of the simulated galaxies are not identified as mergers during the strong interaction phase, implying that galaxies undergoing violent merging process do not necessarily exhibit highly asymmetric kinematics in their star-forming gas. The lack of identifiable merger signatures in this population can lead to an underestimation of merger abundances in star-forming galaxies, and including them in samples of star-forming disks may bias the measurements of disk properties such as intrinsic velocity dispersion.