bluuebunny/crossref_metadata_2025 huggingface dataset:
Double Neutron Star Mergers and Short Gamma-ray Bursts: Long-lasting High-energy Signatures and Remnant Dichotomy
Authors: Murase Kohta , Toomey Michael W. , Fang Ke , Oikonomou Foteini , Kimura Shigeo S. , Hotokezaka Kenta , Kashiyama Kazumi , Ioka Kunihito , Mészáros Peter
Published: February 2018

The recent detection of gravitational waves and electromagnetic counterparts from the double neutron star merger event GW+EM170817 supports the standard paradigm of short gamma-ray bursts (SGRBs) and kilonovae/macronovae. It is important to reveal the nature of the compact remnant left after the merger, either a black hole or neutron star, and their physical link to the origin of the long-lasting emission observed in SGRBs. The diversity of the merger remnants may also lead to different kinds of transients that can be detected in future. Here we study the high-energy emission from the long-lasting central engine left after the coalescence, under certain assumptions. In particular, we consider the X-ray emission from a remnant disk and the nonthermal nebular emission from disk-driven outflows or pulsar winds. We demonstrate that late-time X-ray and high-frequency radio emission can provide useful constraints on properties of the hidden compact remnants and their connections to long-lasting SGRB emission, and we discuss the detectability of nearby merger events through late-time observations at ∼30–100 days after the coalescence. We also investigate the GeV–TeV gamma-ray emission that occurs in the presence of long-lasting central engines and show the importance of external inverse Compton radiation due to upscattering of X-ray photons by relativistic electrons in the jet. We also search for high-energy gamma rays from GW170817 in the Fermi-LAT data and report upper limits on such long-lasting emission. Finally, we consider the implications of GW+EM170817 and discuss the constraints placed by X-ray and high-frequency radio observations.
Using Cross Entropy Optimization to Model Active Galactic Nuclei Light Curves from VLBA MOJAVE Images
Authors: Vitoriano R. P. , Botti L. C. L.
Published: February 2018

We present in this article a new method to derive the observed properties of outbursts in relativistic jets. We use the VLBI MOJAVE maps to obtain the light curves, based on the principle that the variability of extragalactic sources, in this case 3C 279 and 4C +29.45, should appear in high resolution observations since 1996 until 2016. The use of the cross entropy method (CE) can accurately determine the ranges of parameters for a sequence of outbursts based on the shock-wave model, where the decay/rise timescale ratio has a small spread and the use of a unique index 1.3 generates a good fit modeled by functions of outbursts and by the model of the three stages. By the CE method, one can automatically get the start epochs as well as the occurrence of rise and decline times of the outbursts in the light curves. The values found are in agreement with the power-law distribution of energy, which shows that the cooling of electrons is a predominant process during the initial phase of the shock model evolution. The results of the decomposition show that the outbursts match the VLBI components observed in jets in addition to showing strong evidence of the peaks in the frequencies of 15.3 GHz. With this, we can model the shock waves with reference to the distance at the core of AGN to obtain the Doppler factor and the Lorentz factor.
Thermal Emission in the Quiescent Neutron Star SAX J1810.8-2609
Authors: Allen Jessamyn L. , Homan Jeroen , Chakrabarty Deepto , Nowak Michael
Published: February 2018

We have observed the neutron star low-mass X-ray binary SAX J1810.8−2609 in quiescence with XMM-Newton. SAX J1810.8−2609 is one of the faintest non-pulsing neutron star low-mass X-ray binaries in quiescence and previously only had upper limits on its quiescent thermal emission. We found SAX J1810.8−2609 at the same 0.5–10 keV, unabsorbed luminosity as the previous quiescent observation in 2003,

erg s−1. We show that the spectrum requires both thermal and nonthermal components, each contributing approximately half the total emission. The low neutron star luminosity suggests a time-averaged outburst accretion rate of

M
⊙ yr−1, in conflict with its observed outburst activity corresponding to a mass accretion rate that is an order of magnitude larger (

M
⊙ yr−1). Our observation designates SAX J1810.8−2609 more firmly as a member of a population of faint quiescent neutron star LMXBs whose quiescent thermal luminosity is not aligned with standard cooling models.
Explanation of the Knee-like Feature in the DAMPE Cosmic
Energy Spectrum
Authors: Fang Kun , Bi Xiao-Jun , Yin Peng-Fei
Published: February 2018

The DArk Matter Particle Explorer, a space-based high precision cosmic-ray detector, has just reported the new measurement of the total electron plus positron energy spectrum up to 4.6 TeV. A notable feature in the spectrum is the spectral break at ∼0.9 TeV, with the spectral index softening from −3.1 to −3.9. Such a feature is very similar to the knee at the cosmic nuclei energy spectrum. In this work, we propose that the knee-like feature can be explained naturally by assuming that the electrons are accelerated at the supernova remnants (SNRs) and released when the SNRs die out with lifetimes around 105 years. The cut-off energy of those electrons have already decreased to several TeV due to radiative cooling, which may induce the observed TeV spectral break. Another possibility is that the break is induced by a single nearby old SNR. Such a scenario may bring a large electron flux anisotropy that may be observable by the future detectors. We also show that a minor part of electrons escaping during the acceleration in young and nearby SNRs is able to contribute to a several TeV or higher energy region of the spectrum.
ALMA Dust Polarization Observations of Two Young Edge-on Protostellar Disks
Authors: Lee Chin-Fei , Li Zhi-Yun , Ching Tao-Chung , Lai Shih-Ping , Yang Haifeng
Published: February 2018

Polarized emission is detected in two young nearly edge-on protostellar disks in 343 GHz continuum at ∼50 au (∼0.″12) resolution with Atacama Large Millimeter/submillimeter Array. One disk is in HH 212 (Class 0) and the other in the HH 111 (early Class I) protostellar system. The polarization fraction is ∼1%. The disk in HH 212 has a radius of ∼60 au. The emission is mainly detected from the nearside of the disk. The polarization orientations are almost perpendicular to the disk major axis, consistent with either self-scattering or emission by grains aligned with a poloidal field around the outer edge of the disk because of the optical depth effect and temperature gradient; the presence of a poloidal field would facilitate the launching of a disk wind, for which there is already tentative evidence in the same source. The disk of HH 111 VLA 1 has a larger radius of ∼220 au and is thus more resolved. The polarization orientations are almost perpendicular to the disk major axis in the nearside, but more along the major axis in the farside, forming roughly half of an elliptical pattern there. It appears that toroidal and poloidal magnetic field may explain the polarization on the near and far sides of the disk, respectively. However, it is also possible that the polarization is due to self-scattering. In addition, alignment of dust grains by radiation flux may play a role in the farside. Our observations reveal a diversity of disk polarization patterns that should be taken into account in future modeling efforts.
Mapping Circumstellar Matter with Polarized Light: The Case of Supernova 2014J in M82
Authors: Yang 杨 Yi 轶 , Wang Lifan , Baade Dietrich , Brown Peter. J. , Cikota Aleksandar , Cracraft Misty , Höflich Peter A. , Maund Justyn R. , Patat Ferdinando , Sparks William B. , Spyromilio Jason , Stevance Heloise F. , Wang Xiaofeng , Wheeler J. Craig
Published: February 2018

Optical polarimetry is an effective way of probing the environment of a supernova for dust. We acquired linear HST ACS/WFC polarimetry in bands

,

, and

of the supernova (SN) 2014J in M82 at six epochs from ∼277 days to ∼1181 days after the B-band maximum. The polarization measured at day 277 shows conspicuous deviations from other epochs. These differences can be attributed to at least ∼

of circumstellar dust located at a distance of

from the SN. The scattering dust grains revealed by these observations seem to be aligned with the dust in the interstellar medium that is responsible for the large reddening toward the supernova. The presence of this circumstellar dust sets strong constraints on the progenitor system that led to the explosion of SN 2014J; however, it cannot discriminate between single- and double-degenerate models.
Neutrinos and Ultra-high-energy Cosmic-ray Nuclei from Blazars
Authors: Rodrigues Xavier , Fedynitch Anatoli , Gao Shan , Boncioli Denise , Winter Walter
Published: February 2018

We discuss the production of ultra-high-energy cosmic-ray (UHECR) nuclei and neutrinos from blazars. We compute the nuclear cascade in the jet for both BL Lac objects and flat-spectrum radio quasars (FSRQs), and in the ambient radiation zones for FSRQs as well. By modeling representative spectral energy distributions along the blazar sequence, two distinct regimes are identified, which we call “nuclear survival” (typically found in low-luminosity BL Lacs) and “nuclear cascade” (typically found in high-luminosity FSRQs). We quantify how the neutrino and cosmic-ray (CR) emission efficiencies evolve over the blazar sequence, and we demonstrate that neutrinos and CRs come from very different object classes. For example, high-frequency-peaked BL Lacs (HBLs) tend to produce CRs, and high-luminosity FSRQs are the more efficient neutrino emitters. This conclusion does not depend on the CR escape mechanism, for which we discuss two alternatives (diffusive and advective escape). Finally, the neutrino spectrum from blazars is shown to significantly depend on the injection composition into the jet, especially in the nuclear cascade case: Injection compositions heavier than protons lead to reduced neutrino production at the peak, which moves at the same time to lower energies. Thus, these sources will exhibit better compatibility with the observed IceCube and UHECR data.
HD 104860 and HD 192758: Two Debris Disks Newly Imaged in Scattered Light with the Hubble Space Telescope
Authors: Choquet É. , Bryden G. , Perrin M. D. , Soummer R. , Augereau J.-C. , Chen C. H. , Debes J. H. , Gofas-Salas E. , Hagan J. B. , Hines D. C. , Mawet D. , Morales F. , Pueyo L. , Rajan A. , Ren B. , Schneider G. , Stark C. C. , Wolff S.
Published: February 2018

We present the first scattered-light images of two debris disks around the F8 star HD 104860 and the F0V star HD 192758, respectively ∼45 and ∼67 pc away. We detected these systems in the F110W and F160W filters through our reanalysis of archival Hubble Space Telescope (HST) NICMOS data with modern starlight-subtraction techniques. Our image of HD 104860 confirms the morphology previously observed by Herschel in thermal emission with a well-defined ring at a radius of ∼114 au inclined by ∼58°. Although the outer edge profile is consistent with dynamical evolution models, the sharp inner edge suggests sculpting by unseen perturbers. Our images of HD 192758 reveal a disk at radius ∼95 au inclined by ∼59°, never resolved so far. These disks have low scattering albedos of 10% and 13%, respectively, inconsistent with water ice grain compositions. They are reminiscent of several other disks with similar inclination and scattering albedos: Fomalhaut, HD 92945, HD 202628, and HD 207129. They are also very distinct from brighter disks in the same inclination bin, which point to different compositions between these two populations. Varying scattering albedo values can be explained by different grain porosities, chemical compositions, or grain size distributions, which may indicate distinct formation mechanisms or dynamical processes at work in these systems. Finally, these faint disks with large infrared excesses may be representative of an underlying population of systems with low albedo values. Searches with more sensitive instruments on HST or on the James Webb Space Telescope and using state-of-the art starlight-subtraction methods may help discover more of such faint systems.
Sub-Chandrasekhar-mass White Dwarf Detonations Revisited
Authors: Shen Ken J. , Kasen Daniel , Miles Broxton J. , Townsley Dean M.
Published: February 2018

The detonation of a sub-Chandrasekhar-mass white dwarf (WD) has emerged as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. Recent studies have suggested that the rapid transfer of a very small amount of helium from one WD to another is sufficient to ignite a helium shell detonation that subsequently triggers a carbon core detonation, yielding a “dynamically driven double-degenerate double-detonation” SN Ia. Because the helium shell that surrounds the core explosion is so minimal, this scenario approaches the limiting case of a bare C/O WD detonation. Motivated by discrepancies in previous literature and by a recent need for detailed nucleosynthetic data, we revisit simulations of naked C/O WD detonations in this paper. We disagree to some extent with the nucleosynthetic results of previous work on sub-Chandrasekhar-mass bare C/O WD detonations; for example, we find that a median-brightness SN Ia is produced by the detonation of a 1.0

WD instead of a more massive and rarer 1.1

WD. The neutron-rich nucleosynthesis in our simulations agrees broadly with some observational constraints, although tensions remain with others. There are also discrepancies related to the velocities of the outer ejecta and light curve shapes, but overall our synthetic light curves and spectra are roughly consistent with observations. We are hopeful that future multidimensional simulations will resolve these issues and further bolster the dynamically driven double-degenerate double-detonation scenario’s potential to explain most SNe Ia.
Psychiatric Treatment in Forensic Hospital and Correctional Settings
Authors: Kapoor Reena , Dike Charles C. , Norko Michael A.
Published: February 2018

Many psychiatric patients are treated in forensic settings, including correctional facilities and high-security hospitals. This article provides mental health practitioners with essential knowledge about forensic settings to enhance their clinical care of patients involved with the criminal justice system. The article provides an overview of the interface between the mental health and criminal justice systems and discusses the unique aspects of psychiatric care in forensic settings, such as the need to balance treatment with security concerns and to manage patients' violence risk. The critical role of community mental health providers in the primary prevention of criminal justice involvement is also discussed.

[
Psychiatr Ann.
2018;48(2):102–108.]
Psychiatric Disability Evaluations
Authors: Noffsinger Stephen G. , Saxton Adrienne , Ostermeyer Britta
Published: February 2018

Mental illness and substance abuse disorders are among the most frequent causes of disability in the United States and the world, rendering many people unable to be gainfully employed. As a result, psychiatrists and other mental health professionals often receive requests to perform independent medical examinations (IMEs) to provide opinions pertaining to a person's disability, work accommodation requirements, or fitness for duty. This article provides psychiatrists and other mental health professionals who conduct these examinations with pertinent background information as well as information about the examination process and report writing so they can perform a psychiatric IME when requested by lawyers, employers, or insurance companies. This article also uses an Illustrative Case to facilitate a better understanding of the information provided.

[
Psychiatr Ann.
2018;48(2):86–94.]
Examining Decision-Making: Understanding Civil and Criminal Competencies
Authors: Ostermeyer Britta , Anacker Lisa , Perdue Jedidiah , Saxton Adrienne , Noffsinger Stephen G.
Published: February 2018

Psychiatrists and mental health professionals in the role of forensic examiners require certain knowledge and skills to perform competency examinations, which are the most common type of forensic mental health examinations. Competency refers to necessary basic abilities to make certain decisions, such as medical treatment decisions in the civil legal arena. In criminal proceedings, the most common evaluation is the competency to stand trial examination. This article discusses competencies in general, with a focus on medical decision-making capacity and competency to stand trial.[Psychiatr Ann.2018;48(2):79–85.]
Análisis de ciclo de vida de los paneles de lana mineral de vidrio para la construcción de conductos de climatización. Verificación externa
Authors: Herranz García S. , García Navarro J.
Published: February 2018

El presente trabajo expone la situación actual del comportamiento ambiental, a lo largo de su ciclo de vida, de los conductos de climatización realizados con paneles de lana mineral de vidrio. Su uso cada vez es más habitual en la realización de instalaciones de alta eficiencia, sustituyendo frecuentemente a los conductos de chapa metálica revestidos con mantas de lana mineral de vidrio, debido a las ventajas que aportan a la instalación. El análisis del ciclo de vida nos permite cuantificar el impacto medioambiental de estos productos. El procedimiento será realizado utilizando como base la norma UNE-EN 15804:2012+A1, que define el marco común para armonizar la estructura de las Declaraciones Ambientales de Producto en materiales de construcción y da veracidad con base científica a los datos ambientales aportados, al ser verificados por un tercero.
Affaire Boukrourou contre France : nouvelle condamnation symptomatique d’une relation tourmentée entre forces de l’ordre et citoyens
Authors: Achkouyan Laura , Lusson Juliette , Fazolo Indiara
Published: February 2018

La Cour européenne des droits de l’homme condamne une fois de plus l’État français pour traitements inhumains et dégradants infligés par les services de police. Dans son analyse, la Cour fait preuve de prudence concernant l’obligation de protection de la vie et retient l’argument de l’imprévisibilité des conséquences mortelles de l’interpellation. Toutefois, intégrant le sentiment prégnant d’impunité des forces de l’ordre, la Cour juge l'action policière contraire à l'article 3 de la Convention et met en évidence le fossé existant entre son appréciation et celle des juridictions nationales…
Reciprocal Regulation of Glycolysis-Driven Th17 Pathogenicity and Regulatory T Cell Stability by Cdc42
Authors: Kalim Khalid W. , Yang Jun-Qi , Li Yuan , Meng Yan , Zheng Yi , Guo Fukun
Published: February 2018

A balance between Th17 cells and regulatory T cells (Tregs) is important for host immunity and immune tolerance. The underlying molecular mechanisms remain poorly understood. Here we have identified Cdc42 as a central regulator of Th17/Treg balance. Deletion of Cdc42 in T cells enhanced Th17 differentiation but diminished induced Treg differentiation and suppressive function. Treg-specific deletion of Cdc42 decreased natural Tregs but increased effector T cells including Th17 cells. Notably, Cdc42-deficient Th17 cells became pathogenic associated with enhanced glycolysis and Cdc42-deficient Tregs became unstable associated with weakened glycolytic signaling. Inhibition of glycolysis in Cdc42-deficient Th17 cells diminished their pathogenicity and restoration of glycolysis in Cdc42-deficient Tregs rescued their instability. Intriguingly, Cdc42 deficiency in T cells led to exacerbated wasting disease in mouse models of colitis and Treg-specific deletion of Cdc42 caused early, fatal lymphoproliferative diseases. In summary, we show that Cdc42 is a bona fide regulator of peripheral tolerance through suppression of Th17 aberrant differentiation/pathogenicity and promotion of Treg differentiation/stability/function involving metabolic signaling and thus Cdc42 pathway might be harnessed in autoimmune disease therapy.
Csf1r-mApple Transgene Expression and Ligand Binding In Vivo Reveal Dynamics of CSF1R Expression within the Mononuclear Phagocyte System
Authors: Hawley Catherine A. , Rojo Rocio , Raper Anna , Sauter Kristin A. , Lisowski Zofia M. , Grabert Kathleen , Bain Calum C. , Davis Gemma M. , Louwe Pieter A. , Ostrowski Michael C. , Hume David A. , Pridans Clare , Jenkins Stephen J.
Published: February 2018

CSF1 is the primary growth factor controlling macrophage numbers, but whether expression of the CSF1 receptor differs between discrete populations of mononuclear phagocytes remains unclear. We have generated a Csf1r-mApple transgenic fluorescent reporter mouse that, in combination with lineage tracing, Alexa Fluor 647–labeled CSF1-Fc and CSF1, and a modified ΔCsf1–enhanced cyan fluorescent protein (ECFP) transgene that lacks a 150 bp segment of the distal promoter, we have used to dissect the differentiation and CSF1 responsiveness of mononuclear phagocyte populations in situ. Consistent with previous Csf1r-driven reporter lines, Csf1r-mApple was expressed in blood monocytes and at higher levels in tissue macrophages, and was readily detectable in whole mounts or with multiphoton microscopy. In the liver and peritoneal cavity, uptake of labeled CSF1 largely reflected transgene expression, with greater receptor activity in mature macrophages than monocytes and tissue-specific expression in conventional dendritic cells. However, CSF1 uptake also differed between subsets of monocytes and discrete populations of tissue macrophages, which in macrophages correlated with their level of dependence on CSF1 receptor signaling for survival rather than degree of transgene expression. A double ΔCsf1r-ECFP-Csf1r-mApple transgenic mouse distinguished subpopulations of microglia in the brain, and permitted imaging of interstitial macrophages distinct from alveolar macrophages, and pulmonary monocytes and conventional dendritic cells. The Csf1r-mApple mice and fluorescently labeled CSF1 will be valuable resources for the study of macrophage and CSF1 biology, which are compatible with existing EGFP-based reporter lines.
Central Nervous System Anomalies Detectable in the First Trimester
Authors: Viora Elsa , Polarolo Giulia , Bastonero Simona , Gullino Elena , Stillavato Silvia , Sciarrone Andrea
Published: February 2018

Prenatal diagnosis of central nervous system (CNS) congenital anomalies is possible in the second and third trimester. Earlier diagnosis is possible for some of these as the complex acranial/exencephaly/anencephaly and alobar holoprosencephaly (HPE).

The knowledge of normal fetal brain development and its ultrasound images at the different weeks’ gestation, the expertise of operators, and high-resolution equipment are essential to obtain good results.

The diagnosis in the first trimester of some major anomalies incompatible with extrauterine life or associated with severe handicap is useful to inform the couple, to perform additional examinations, and provide them with the option of earlier and safer pregnancy termination.

For some other conditions, like agenesis of corpus callosum and hypoplasia or absence of cerebellar vermis, the diagnosis is possible only in the second trimester, so beware not to falsely reassure or scare expecting parents.

In conclusion, first trimester ultrasound could be useful for early detection of some CNS anomalies, but caution could be used for others, particularly in counseling couples about prognostic significant of ultrasound findings.

How to cite this article

Viora E, Polarolo G, Bastonero S, Gullino E, Stillavato S, Sciarrone A. Central Nervous System Anomalies Detectable in the First Trimester. Donald School J Ultrasound Obstet Gynecol 2017;11(4):261-267.
Ventriculomegaly
Authors: Capuano Pasquale , Sciarrone Andrea , Di Cagno Luca , Cialdella Mariangela
Published: February 2018

Fetal cerebral ventriculomegaly (VM) is defined as an enlargement of the lateral ventricles of the developing fetal brain. It is diagnosed when the width of one or both lateral ventricles, measured at the level of the atrium, is ≥10 mm. Ventriculomegaly is defined as mild when the atrial width is 10 to 12 mm, moderate 12.1 to 15 mm, and severe >15 mm. It can be isolated, but often is a sign of different pathological conditions. Since the prognosis in cases of VM depends mainly on the associated anomalies, a careful examination of the fetus, particularly of the brain, is mandatory. Magnetic resonance imaging (MRI) can be a useful diagnostic tool complementary to ultrasound in order to recognize subtle brain anomalies, such as neuronal migration and proliferation disorders. In this review article, the diagnostic workup, the counseling, and the outcome of fetal VM are discussed.

How to cite this article

D’Addario V, Di Cagno L, Capuano P, Cialdella M. Ventriculomegaly. Donald School J Ultrasound Obstet Gynecol 2017;11(4):276-281.
Fetal Central Nervous System and Infectious Diseases
Authors: Masini Lucia , Apicella Massimo , Luca Carmen De , Valentini Piero , Manfredi Riccardo , Lanzone Antonio , Santis Marco De
Published: February 2018

Maternal infectious diseases are frequent complications of pregnancy and can cause negative outcomes. Perinatal infections can cause serious damage to fetal central nervous system (CNS), but incidence of symptomatic congenital infections at birth is low. Complete and multidisciplinary (obstetric, infectologist, microbiologist, neonatologist/pediatrician, psychologist) evaluation of the pregnant women is crucial to define fetal prognosis. The ultrasound (US) surveillance has an irreplaceable role in identifying serious fetal damage and complications. Complete evaluation of the fetus in selected cases needs to be integrated with invasive prenatal diagnosis, particularly amniocentesis, which has optimal predictive values in excluding vertical transmission, and fetal magnetic resonance imaging (MRI), which can add important anatomical detail when fetal CNS damage is suspected. Congenital infections, furthermore, need to be considered in differential diagnosis of some common abnormal CNS findings at prenatal US. With the present review, we intend to provide an overview of the major perinatal infections and the role of US diagnosis in their assessment to recognize fetal CNS damage. We highlight the most recognizable syndromes due to congenital infections by linking etiopathogenesis with pathology and imaging. In particular, we focus on US diagnostic and prognostic values in relation to other invasive and noninvasive prenatal diagnosis options and summarize up-to-date recommendations on US evaluation of most common findings. Cytomegalovirus (CMV) is the most common cause of congenital infection, while Toxoplasmosis is the most preventable cause of infectious CNS damage; rubella, varicella virus, and herpes viruses, even if rarely, may be responsible for extremely serious fetal damage, while Zika virus is an emerging concern on global scale.

How to cite this article

Masini L, Apicella M, De Luca C, Valentini P, Manfredi R, Lanzone A, De Santis M. Fetal Central Nervous System and Infectious Diseases. Donald School J Ultrasound Obstet Gynecol 2017;11(4):314-327.
Central Nervous System and Cardiovascular Diseases
Authors: Arduini Maurizio
Published: February 2018

Children with congenital heart diseases (CHD) are at increased risk of neurodevelopmental delay (NDD). In fetuses with CHD, blood streaming in the brain may be partially deoxygenated. Signs of cerebrovascular autoregulation comparable to the “brain-sparing effect” in growth-restricted fetuses may be shown in fetuses with CHD depending on the type of heart disease. This effect appears to be predominantly present in fetuses with left-side obstructive lesions (LSOL). During prenatal counseling, it is recommended to mention the possibility of an increased risk of NDD. The severity of this impairment varies from the type of CHD, being highest up to 40 to 45% in lesions with univentricular heart hemodynamics, such as hypoplastic left heart syndrome (HLHS).

The prenatal life plays an important role in determining postnatal neurodevelopmental functions, but the severity of NDD in fetuses with CHD cannot be predicted prenatally.

How to cite this article

Arduini M. Central Nervous System and Cardiovascular Diseases. Donald School J Ultrasound Obstet Gynecol 2017;11(4):362-366.
Fungal Infective Endocarditis mimicking Atrial Myxoma: Transesophageal Echocardiography Assessment
Authors: Irpachi Kalpna , Makhija Neeti , Rajashekar Palleti , Bharat Siddharth Ch
Published: February 2018

Infective endocarditis (IE) accounts for 0.5 to 1 of every 1,000 hospital admissions. This case describes a left atrial mass of fungal etiology mimicking an atrial myxoma. At times, the diagnosis of mass in left atrium can be a challenge, which is discussed in this report.

How to cite this article

Makhija N, Irpachi K, Rajashekar P, Siddharth CB. Fungal Infective Endocarditis mimicking Atrial Myxoma: Transesophageal Echocardiography Assessment. J Perioper Echocardiogr 2017;5(2):82-85.
Atmospheric carbonyl sulfide (OCS) measured remotely by FTIR solar absorption spectrometry
Authors: Toon Geoffrey C. , Blavier Jean-Francois L. , Sung Keeyoon
Published: February 2018

Abstract. Atmospheric OCS abundances have been retrieved from infrared spectra measured by the Jet Propulsion Laboratory (JPL) MkIV Fourier transform infra-red (FTIR) spectrometer during 24 balloon flights and during nearly 1100 days of ground-based observations since 1985. Our spectral fitting approach uses broad windows to enhance the precision and robustness of the retrievals. Since OCS has a vertical profile similar in shape to that of N2O, and since tropospheric N2O is very stable, we reference the OCS observations to those of N2O, measured simultaneously in the same air mass, to remove the effects of stratospheric transport, allowing a clearer assessment of secular changes in OCS. Balloon measurements reveal less than 5 % change in stratospheric OCS amounts over the past 25 years. Ground-based measurements reveal a springtime peak of tropospheric OCS, followed by a rapid early-summer decrease, similar to the behavior of CO2. This results in a peak-to-peak seasonal cycle of 5–6 % of the total OCS column at northern mid-latitudes. In the long-term tropospheric OCS record, a 5 % decrease is seen from 1990 to 2002, followed by a 5 % increase from 2003 to 2012.
Folded Tubular Photometer for atmospheric measurements of NO2 and NO
Authors: Birks John W. , Andersen Peter C. , Williford Craig J. , Turnipseed Andrew A. , Strunk Stanley E. , Ennis Christine A. , Mattson Erick
Published: February 2018

Abstract. We describe and characterize a modular Folded Tubular Photometer for making direct measurements of the concentrations of air pollutants such as nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and black carbon particulate matter. Direct absorbance measurements using this photometer can be made across the spectral range from the ultraviolet (UV) to the near-infrared. The absorbance cell makes use of modular components (tubular detection cells and mirror cubes) that allow construction of path lengths of up to 2 meters or more while maintaining low cell volumes. The long path lengths and low cell volumes enable sensitive detection of ambient air pollutants down to low part-per-billion levels for gas species and aerosol extinctions down to 1 Mm−1, corresponding to ~ 0.1 μg m−3 for black carbon particulates. Pressure equalization throughout the stages of the absorbance measurement is shown to be critical to accurate measurements of analyte concentrations. The present paper describes the application of this photometer to direct measurements of nitrogen dioxide (NO2) and the incorporation of design features that also enable measurement of nitric oxide (NO) in the same instrument. Excellent agreement for ambient measurements along an urban roadside was found for both NO2 and NO measured by the Folded Tubular Photometer compared to existing standard techniques. Compared to commonly used methods for measurements of NOx species, the advantages of this approach include 1) an absolute quantification for NO2 based on the Beer-Lambert Law, thereby greatly reducing the frequency at which calibrations are required; 2) the direct measurement of NO2 concentration without prior conversion to NO as is required for the commonly used chemiluminescence method; 3) the use of modular components that allow construction of absorbance detection cells of varying lengths for extending the dynamic range of concentrations that can be measured; 4) a more economical instrument than other currently available direct measurement techniques for NO2; and 5) the potential for simultaneous detection of additional species such as SO2, O3, and black carbon in the same instrument. In contrast to other commercially available direct NO2 measurements, such as cavity-attenuated phase shift spectroscopy (CAPS), the Folded Tubular Photometer provides a means for measuring NO simultaneously in the same apparatus by quantitatively converting NO to NO2 with ozone, which is then detected by direct absorbance.
Quantifying the single scattering albedo for the January 2017 Chile wildfires from simulations of the OMI absorbing aerosol index
Authors: Sun Jiyunting , Veefkind J. Pepijn , van Velthoven Peter , Levelt Pieternel F.
Published: February 2018

Abstract. The absorbing aerosol index (AAI) based on the near Ultra-Violet (near-UV) remote sensing techniques is a qualitative parameter that allows to retrieve aerosol optical properties with confidence. In the first part of this study, a series of AAI sensitivity analysis is presented exclusively on biomass burning aerosols. Later on, this study applies a radiative transfer model (DISAMAR) to simulate the AAI measured by the Ozone Monitoring Instrument (OMI) and to derive the aerosol single scattering albedo (ω0). The inputs for the radiative transfer calculations are satellite measurement geometry and surface conditions from OMI, aerosol optical thickness (τ) from the MODerate-resolution Imaging Spectroradiometer (MODIS), and aerosol micro-physical parameters from the AErosol RObotic NETwork (AERONET), respectively. This approach is applied to the Chile wildfires for the period from 26 to 30 January 2017, when the OMI observed AAI of this event reached its peak. The Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP) failed to capture the evolution of the smoke plume, therefore the aerosol profile is parameterized. The simulated plume ascends to an altitude of 4.5–4.9 km, which is in good agreement with measurements. Due to the relatively small data size of this case, an outlier detection criterion has to be applied. The results show that the AAI simulated by DISAMAR is consistent with observations. The correlation coefficients are over 0.85. The retrieved mean ω0 at 550 nm is approximately 0.84, slightly smaller than the value of 0.90 measured independently by the AERONET instrument. The relative distance between the AERONET site and the plume, the assumption of homogeneous and static plume properties, the lack of the aerosol profile information, and the uncertainties in observations are primarily responsible for this discrepancy. Except for the observational errors, the impact of remaining error sources on ω0 retrieval is difficult to quantify.
Differential response of carbon cycling to long-term nutrient input and altered hydrological conditions in a continental Canadian peatland
Authors: Berger Sina , Praetzel Leandra S. E. , Goebel Marie , Blodau Christian , Knorr Klaus-Holger
Published: February 2018

Abstract. Peatlands play an important role in global carbon cycling, but
their responses to long-term anthropogenically changed hydrologic conditions
and nutrient infiltration are not well known. While experimental manipulation
studies, e.g., fertilization or water table manipulations, exist on the plot
scale, only few studies have addressed such factors under in situ conditions.
Therefore, an ecological gradient from the center to the periphery of a continental
Canadian peatland bordering a eutrophic water reservoir, as reflected by
increasing nutrient input, enhanced water level fluctuations, and increasing
coverage of vascular plants, was used for a case study of carbon cycling
along a sequence of four differently altered sites. We monitored carbon
dioxide (CO2) and methane (CH4) surface fluxes and dissolved
inorganic carbon (DIC) and CH4 concentrations in peat profiles from
April 2014 through September 2015. Moreover, we studied bulk peat and
pore-water quality and we applied δ13C–CH4 and
δ13C–CO2 stable isotope abundance analyses to
examine dominant CH4 production and emission pathways during the
growing season of 2015. We observed differential responses of carbon cycling
at the four sites, presumably driven by abundances of plant functional types
and vicinity to the reservoir. A shrub-dominated site in close vicinity to
the reservoir was a comparably weak sink for CO2 (in
1.5 years: −1093 ± 794, in 1 year:
+135 ± 281 g CO2 m−2; a net release) as compared
to two graminoid-moss-dominated sites and a moss-dominated site (in
1.5 years: −1552 to −2260 g CO2 m−2, in
1 year: −896 to −1282 g CO2 m−2). Also, the shrub-dominated site featured notably low DIC pore-water concentrations
and
comparably 13C-enriched CH4
(δ13C– CH4: −57.81 ± 7.03 ‰) and
depleted CO2 (δ13C–CO2:
−15.85 ± 3.61 ‰) in a more decomposed peat, suggesting
a higher share of CH4 oxidation and differences in predominant
methanogenic pathways. In comparison to all other sites, the graminoid-moss-dominated site in closer vicinity to the reservoir featured
a ∼ 30 % higher CH4 emission (in 1.5 years:
+61.4 ± 32, in 1 year:
+39.86 ± 16.81 g CH4 m−2). Low
δ13C–CH4 signatures
(−62.30 ± 5.54 ‰) indicated only low mitigation of
CH4 emissions by methanotrophic activity here. Pathways of
methanogenesis and methanotrophy appeared to be related to the vicinity to
the water reservoir: the importance of acetoclastic CH4 production
apparently increased toward the reservoir, whereas the importance of
CH4 oxidation increased toward the peatland center. Plant-mediated
transport was the prevailing CH4 emission pathway at all sites even
where graminoids were rare. Our study thus illustrates accelerated carbon
cycling in a strongly altered peatland with consequences for CO2 and
CH4 budgets. However, our results suggest that long-term excess
nutrient input does not necessarily lead to a loss of the peatland carbon
sink function.
Basic and extensible post-processing of eddy covariance flux data with REddyProc
Authors: Wutzler Thomas , Lucas-Moffat Antje , Migliavacca Mirco , Knauer Jürgen , Sickel Kerstin , Šigut Ladislav , Menzer Olaf , Reichstein Markus
Published: February 2018

Abstract. With the eddy-covariance (EC) technique, net fluxes of carbon dioxide (CO2) and other greenhouse gases as well as water and energy fluxes can be measured at the ecosystem level. These flux measurements are a main source for understanding biosphere-atmosphere interactions and feedbacks by cross-site analysis, model-data integration, and up-scaling. The raw fluxes measured with the EC technique require an extensive and laborious data processing. While there are standard tools available in open source environment for processing high-frequency (10 or 20 Hz) data into half-hourly quality checked fluxes, there is a need for more usable and extensible tools for the subsequent post-processing steps. We tackled this need by developing the REddyProc package in the cross-platform language R that provides standard CO2-focused post-processing routines for reading (half-)hourly data from different formats, estimating the uStar threshold, gap-filling, flux-partitioning, and visualizing the results. In addition to basic processing, the functions are extensible and allow easier integration in extended analysis than current tools. New features include cross year processing and a better treatment of uncertainties. A comparison of REddyProc routines with other state-of the art tools resulted in no significant differences in monthly and annual fluxes across sites. Lower uncertainty estimates of both uStar and resulting gap-filled fluxes with the presented tool was achieved by an improved treatment of seasons during the bootstrap analysis. Higher estimates of uncertainty in day-time partitioning resulted from a better accounting of the uncertainty in estimates of temperature sensitivity of respiration. The provided routines can be easily installed, configured, used, and integrated with further analysis. Hence the eddy covariance community will benefit from using the provided package, allowing easier integration of standard post-processing with extended analysis.
First in situ estimations of small phytoplankton carbon and nitrogen uptake rates in the Kara, Laptev, and East Siberian seas
Authors: Sadanandan Bhavya P. , Lee Jang Han , Lee Ho Won , Kaang Jae Joong , Lee Jae Hyung , Lee Dabin , An So Hyun , Stockwell Dean A. , Whitledge Terry E. , Lee Sang Heon
Published: February 2018

Abstract. Carbon and nitrogen uptake rates by small phytoplankton (0.7–5 μm) in the Kara, Laptev, and East Siberian seas in the Arctic Ocean were quantified using in situ isotope labelling experiments for the first time as part of the NABOS (Nansen and Amundsen Basins Observational System) program during August 21 to September 22, 2013. The depth integrated C, NO3−, and NH4+ uptake rates by small phytoplankton showed a wide range from 0.54 to 15.96 mg C m−2 h−1, 0.05 to 1.02 and 0.11 to 3.73 mg N m−2 h−1, respectively. The contributions of small phytoplankton towards the total C, NO3−, and NH4+ was varied from 24 to 89 %, 32 to 89 %, and 28 to 89 %, respectively. The turnover times for NO3− and NH4+ by small phytoplankton during the present study point towards the longer residence times (years) of the nutrients in the deeper waters, particularly for NO3−. Relatively, higher C and N uptake rates by small phytoplankton obtained during the present study at locations with less sea ice concentrations points towards the possibility of small phytoplankton thrive under sea ice retreat under warming conditions. The high contributions of small phytoplankton towards the total carbon and nitrogen uptake rates suggest capability of small size autotrophs to withstand in the adverse hydrographic conditions introduced by climate change.
Evaluation of Lacustrine Groundwater Discharge, Hydrologic Partitioning, and Nutrient Budgets in a Proglacial Lake in Qinghai-Tibet Plateau: Using
222Rn and Stable Isotopes
Authors: Luo Xin , Kuang Xing Xing , Jiao Jiu Jimmy , Liang Sihai , Mao Rong , Zhang Xiaolang , Li Hailong
Published: February 2018

Abstract. Proglacial lakes are good natural laboratories to investigate groundwater and glacier dynamics under current climate condition and to explore primary productivity under pristine lake status. This study conducted a series of investigations of 222Rn, stable isotopes, nutrients and other hydrogeochemical parameters in Ximen Co Lake, a remote proglacial lake in the east of Qinghai-Tibet Plateau (QTP). A radon mass balance model was used to quantify the lacustrine groundwater discharge (LGD) of the lake, leading to an LGD estimate of 10.3 ± 8.2 mm d−1. Based on the three end member models of stable 18O and Cl−, the hydrologic partitioning of the lake is obtained, which shows that groundwater discharge only accounts for 7.0 % of the total water input. The groundwater derived DIN and DIP loadings constitute 42.9 % and 5.5 % of the total nutrient loading to the lakes, indicating the significance of LGD in delivering disproportionate DIN into the lake. The primary productivity of the lake water is calculated to be 0.41 mmol C m−2 d−1. This study presents the first attempts to evaluate the LGD and hydrologic partitioning in the glacial lake by coupling radioactive and stable isotopic approaches and the findings advance the understanding of nutrient budgets and primary productivity in the proglacial lakes of QTP. The study is also instructional in revealing the hydrogeochemical processes in proglacial lakes elsewhere.
From lidar scans to roughness maps for wind resource modeling in
forested areas
Authors: Floors Rogier , Enevoldsen Peter , Davis Neil , Arnqvist Johan , Dellwik Ebba
Published: February 2018

Abstract. Applying erroneous roughness lengths can have a large impact on the estimated performance of wind turbines, particularly in forested areas. In this study, a new method called the Objective Roughness Approach (ORA), which converts tree height maps created using airborne lidar scans to roughness maps suitable for wind modeling, is evaluated via cross-predictions between different anemometers at a complex forested site with seven tall meteorological masts using the Wind Atlas Analysis and Application program (WAsP). The cross-predictions were made using ORA maps created at four spatial resolutions and from four freely available roughness maps based on land-use classifications. The validation showed that the use of ORA maps resulted in a closer agreement with observational data for all investigated resolutions compared to the land-use maps. Further, when using the ORA maps, the risk of making large errors (25 %) in predicted power density was reduced by 40–50 % compared to satellite based products with the same resolution. The results could be further improved for high-resolution ORA maps by adding the displacement height. The improvement when using the ORA maps came down to two factors, first they had a higher roughness length for forests, which was confirmed to by increasing the forest roughness value of the land-use based maps to the value of the ORA map, and second, due to the higher resolution of the ORA data, since the ORA maps with the highest resolution had the largest reduction in mean absolute errors.
Wind farm power production assessment: a comparative analysis of two actuator disc methods and two analytical wake models
Authors: Simisiroglou Nikolaos , Polatidis Heracles , Ivanell Stefan
Published: February 2018

Abstract. The aim of the present study is to perform a comparative analysis of two actuator disc methods (ACD) and two analytical wake models for wind farm power production assessment. To do so wind turbine power production data from the Lillgrund offshore wind farm in Sweden is used. The measured power production for individual wind turbines is compared with results from simulations, done in the WindSim software, using two ACD methods (old and new) and two analytical wake models widely used within the wind industry (Jensen and Larsen wake models). It was found that the new ACD method and the Larsen model outperform the other method and model in most cases. Furthermore, results from the new ACD method show a clear improvement in the estimated power production in comparison to the old ACD method. The Jensen method seems to overestimate the power deficit for all cases. The new ACD method, despite it's simplicity, is capable of capturing the power production within the given error margin although it tends to underestimate the power deficit.