bluuebunny/crossref_metadata_2025 huggingface dataset:
Advances in laparoscopic hernia repair (from IPOM to LIRA)
Authors: Gómez Menchero J , Suárez Grau JM , Fernández Carazo A , Morales Conde S
Published: February 2021

Las actuales tendencias de tratamiento de la hernia ventral por vía laparoscópica apuestan por la reconstrucción mínimamente invasiva de la pared. La necesidad de buscar soluciones a la tasa de bulging o de seroma presentes en el IPOM clásico han sido el objetivo de nuevas técnicas como el cierre del defecto que tratan de restablecer anatómicamente la pared abdominal. Tras diez años de cierre del defecto hemos podido comprobar que existen problemas inherentes a la tensión que genera el cierre del defecto, y que existen factores individuales del paciente y de la hernia a tratar que podrían influir negativamente en la recidiva o el bulging por fallo del cierre del defecto.

El desarrollo de una nueva técnica por parte de nuestro grupo (técnica LIRA), nos ha permitido mejorar la fiabilidad de la reconstrucción de la línea media a largo plazo, fundamentalmente en aquellos pacientes con factores de riesgo, garantizando una reconstrucción duradera en aquellos pacientes con hernias de tamaño medio no subsidiarias de técnicas más complejas como una separación de componentes.
The role of the splenic embolization in blunt spleen trauma.
Authors: Alcaide Lucena M , Martínez Domínguez AP , González Puga C , Mirón Pozo B
Published: February 2021

Objetivo: describir el caso de un varón que presenta traumatismo abdominal cerrado con lesión esplénica.

Material y métodos: paciente de 22 años estable hemodinamicamente tras traumatismo abdominal cerrado, con TAC compatible con lesión esplénica y hemoperitoneo moderado con sangrado activo, tratado mediante embolización arterial.

Resultado: evolución tras embolización favorable. Asintomático al año del evento.

Discusión: clásicamente se han tratado mediante esplenectomía los pacientes con traumatismo esplénico con sangrado activo y hemoperitoneo. Describimos la utilización de esta técnica como método eficaz en pacientes hemodinamicamente estables.

Conclusión: la embolización arterial del bazo es una técnica segura y poco agresiva para el tratamiento de las lesiones traumáticas del bazo en pacientes hemodinamicamente estables con sangrado activo.
Retroperitoneoscopy in acute pancreatitis.
Authors: Tinoco González J , Tallón Aguilar L , Sánchez Arteaga A , Perea del Pozo E , Durán Muñoz-Cruzado V , Díaz Gómez D , Tamayo López MJ , Nevado Infante A , Aparicio Sánchez D , Padillo Ruiz J
Published: February 2021

La pancreatitis aguda es un proceso inflamatorio donde el tratamiento médico precoz y una secuencia de abordaje escalonada (step-up approach) reduce, significativamente, la morbilidad y mortalidad. El desarrollo de la laparoscopia ha permitido disponer de abordajes mínimamente invasivos como la retroperitoneoscopia (VARD).

La VARD es una técnica poco invasiva que minimiza la respuesta sistémica al estrés quirúrgico. Ofrece la ventaja de una mejor visualización de las estructuras vasculares pancreáticas y minimiza la lesión de éstas. Permite realizar nuevos lavados y drenajes por vía retroperitoneal, evitando la altísima morbi-mortalidad asociada a una laparotomía.

La VARD es una técnica quirúrgica alternativa, válida y reproducible en el tratamiento de la PAN, que ofrece resultados comparables e incluso superiores, en algunas series, a los de la cirugía abierta, con resultados satisfactorios en cuanto a morbilidad y mortalidad postoperatoria.
Boundary Layer Flow Over a Vertical Cylinder Embedded in a Porous Medium Moving with non Linear Velocity
Authors: Emam Tarek G.
Published: February 2021

In this work, we consider a steady flow of an incompressible fluid over a cylinder which is semi-infinite. The cylinder is embedded in a porous medium and is considered to move vertically with nonlinear velocity. A system of ordinary differential equations is obtained from the partial differential equations governing the motion using a self-similarity transformation. Such system of ordinary differential equations is solved numerically after obtaining the missed initial conditions. The problem has been solved analytically for the linear velocity case. Numerical and analytical results for such case are given to validate the numerical method used.
Re-dispatch and Application of FACTs for Transactions Allocation in Deregulated Electricity Markets
Authors: Jaisingpure Archana , Chandrakar V. K. , Mohril R. M.
Published: February 2021

In the current scenario, transmission cost allocation is one of the significant difficulties arises due to the expansion in power exchanges in transmission open access looked by electric energy area. The proposed method calculates transmission cost allocation by considering bilateral & multilateral transactions. The transmission cost allocation approach in the proposed method derives from equivalent bilateral which states that a small amount of every generator provides with each request in consistently and separated manner. The influence of power flow in network via all lines due to a transaction is measured by power flow solution. This paper discusses the congestion problem in the deregulated electricity market using an optimal power flow (OPF). The transmission lines are uncongested using re-dispatch method and then taxes are calculated for the establishment of the flexible A.C. transmission systems (FACTS) devices in the transmission network to reduce taxes. The excellent location of FACTS device can be identified by the bus on which highest T. The result indicates that the combination of TCSC and SVC incredibly discount the measure of re-dispatched power which provides optimal operating point nearer to the market settlement. Hence, TCSC and SVC gives convenient option to block the execution of transmission estimation utilizing approaches and calculate the transmission price.
Various Disinfecting Methods of Orthodontic Pliers in Daily Clinical Practice: A comparative Study
Authors: Purva Verma, Arvind Sivkumar
Published: February 2021

Introduction: Orthodontic pliers are essential armamentarium in every orthodontic office and should be used

once for one patient, then autoclaved before next use. Clinical orthodontics with higher volume of patients,

requires a quick chair side disinfection method for pliers, also in rural centres with minimum infrastructure

it is a challenge to maintain sterilisation protocols. Various disinfecting agents include alcohols , quaternary

ammonium salts, formaldehyde, chloramine, sodium hypochlorite, spirit, glutaraldehyde etc. are available.

Out of these we compared the commonly available disinfectants including ethyl alcohol, 5% glutaraldehyde,

and 6% sodium hypochlorite to assess their disinfection efficacy after clinical use.

Materials and method: 20 orthodontic pliers were inoculated with Coagulase negative streptococci. The

pliers were divided in 4 groups with 5 pliers in each group. Each group was subjected to different disinfectant

solution with one group aiding as control. The disinfectants used were: spirit (group 1), 5% glutaraldehyde

(group 2), 2% sodium hypochlorite (group 3) and distilled water (control group).

Results: spirit and 5% glutaraldehyde have shown to be potent disinfectants.

Conclusions: Based on these results, we concluded that among the tested methods, disinfection of orthodontic

pliers with spirit and 5% glutaraldehyde are the efficient methods for chair-side disinfection.
Co-Teaching: A Simple Solution That Isn't Simple After All
Authors: Friend Marilyn
Published: February 2021

Among the many programs that professional educators are developing to better help their increasingly diverse students reach their potential, co-teaching is emerging as an innovative and potentially effective approach. As a way to ensure that students with disabilities or other special needs have access to the same curriculum as other students and the opportunity to succeed in the general education setting, co-teaching occurs when two professionals, typically a general education teacher and a special education teacher or another specialist, partner in delivering instruction. Although the research base on co-teaching is still emerging, it suggests that co-teaching is far more complex to effectively implement than it might seem at first consideration. Challenges to co-teaching that have been identified and must be addressed include: arranging time for co-planning, building positive working relationships between co-teaching partners, clarifying roles and responsibilities, and ensuring administrative support. When creative strategies for arranging common planning time, building understanding and collaboration between co-teachers, planning and delivering instruction, and enlisting principal and other administrative supports are implemented, the potential of co-teaching for improving student outcomes is significant.
Investigating Internal Accountability and Collective Capacity: Taking a Closer Look at Mathematics Instruction
Authors: Hall Jori
Published: February 2021

This case study uses multiple methods and gathers perspectives from administrators, teachers, and students to examine how a middle school develops internal accountability (Elmore, 2004) to address the needs of its diverse learners and external accountability mandates. Building on Newmann, King, and Rigdon’s (1997) framework for collective capacity, the school’s capacity to enact its internal accountability is explored. An in-depth investigation within the context of the school’s mathematics program, focusing on the academic needs of low-income, African American learners is conducted to further explore collective capacity as primarily enacted vis-à-vis teachers’ instructional strategies. The data presented contribute to a more complex and contextual perspective of teaching and learning within a high-stakes testing environment. The findings of this study show that despite tensions around student accountability and curricular demands, the school successfully incorporates internally-generated accountability and mandated strategies into their internal accountability system and demonstrates leadership capacity at multiple levels.
COMPREHENSIVE EVALUATION OF EXPRESSION PLATFORM: CHERRY PICKING THE ‘RIGHT’ TO ACCOMPLISH THE ‘BEST
Authors: Gaur Shailendra , Bhadresha Kinjal , Patel Baldev , Saraf Meenu , Rawal Rakesh
Published: February 2021

Mounting demands for biosimilars and continuous emphasis on cost reduction of drugs
have motivated researchers across the globe to widen the horizon of screening in CHO cells based bio-production. Various groups have exploited multiple phenomena in CHO cells for better expression and improved quality of therapeutic protein, for example use of transposons, regulatory elements, engineering of cell lines for site specific integrations or knock-in/knockout models to achieve the desired results. The current study presents the data for evaluation of three mammalian expression platforms available in market having three different approaches for improving productivity. One, the MTX based platforms for gene amplification, GS knock-down based selectionsystem and UCOE based active transcription system. To evaluate the platforms stringently, stable pools of both mAb and non-mAb molecules were accessed. Our results suggested that UCOE based platform have performed exceedingly well in monoclonal antibody (mAb) expression in comparison to the other two platforms. Whereas, for non mAb molecules, UCOE based platform was comparable to other two platforms. On evaluating all the molecules, CHOGS (-) system was found least productive as compared to the other two platforms in almost all cases.
STUDENTS PERCEPTION’S TOWARDS ONLINE TEACHING: AN EMPIRICAL STUDY IN BERHAMPUR UNIVERSITY
Authors: Lakra Bharat Kumar
Published: February 2021

In the Coronavirus disease -19 (COVID-19) response, all the educational institutions
have been compulsory to move all teaching and learning activities online at very short time notice by the University Grand Commission (UGC). Consequently, all classes, simulations, practicums, viva-voces, and valuation, etc., were adapted for the online setting. Online education has been at the forefront of discussions as a new and viable option for learning opportunities in higher education. Academic institutions continue to see remarkable growth of online education during COVID-19. Due to the pandemic situation, UGC has instruction with 40 per cent of online learning. Hence educational institutions have been implementing online classes. The article investigates to identify the factors which students perceive significant influence towards online class. From a student perception, there has been adaptation and the prospect to advance new skills, possibly providing online teaching via elearning or virtual learning. Further, this study sought to provide an investigation of online teaching in University with an intention on how the teaching and learning interaction will affect students ‘perceptions relating to their online class preparedness and experiences. The results revealed from descriptive statistics, correlation, and regression analysis that students reported a moderate relationship between the extracted factor scores and overall satisfaction of online teaching. The findings of four factors that affect the students' views about online teaching characteristics instruction seen that student perceptions about online teaching are positively affected by "Perceived Usefulness” of online teaching. The second most important factor is student supportiveness, followed by faculty responsiveness and perceived flexibility. Further, Multiple Regression Analysis has been analysed to inspect the relationship between the various online teaching characteristics and the overall satisfaction from online teaching. Thus, this study may be helpful to teachers in constructing proper pedagogical techniques which can be suitable and beneficial for learning, understanding and application of the online teaching-learning process.
Акме-орієнтири розвитку представників покоління Z у контексті рефлексивно-проєктної парадигми освіти
Authors: Чумак Л.В.
Published: February 2021

У статті представлено концептуальні положення теорії поколінь у контексті рефлексивно-проєктної парадигми освіти. Її метою визначено виокремлення способів удосконалення освітнього процесу сучасної молоді в напрямі значущих структурних компонентів означеної парадигми освіти. Завданнями дослідження є висвітлення особливостей цифрового покоління і психолого-педагогічного контексту рефлексивно-проєктної парадигми освіти для можливості трансформації їх у наукове поле методологічного і методичного знання з подальшим практичним відтворенням певних базисних положень. Методологічну основу становлять концептуальні положення теорії поколінь; філософські, психологічні та педагогічні аспекти освіти; акме-теорії розвитку особистості як суб’єкта діяльності з використанням історичного наративу; аналіз і узагальнення одержаної інформації щодо психологічних характеристик «цифрових дітей» та значущих структурних компонентів рефлексивно-проєктної парадигми освіти для можливості подальшого більш чіткого проєктування вектора акме-траєкторії означеного феномена як об’єктивної потреби освітньої практики у модернізації. Дослідження виконано в руслі комплексного поєднання особистісного, системно-структурного та контекстного підходів до розгляду акме-орієнтирів розвитку молоді у контексті рефлексивно-проєктної парадигми освіти. Використано такі методи дослідження: структурно-аналітичний метод і порівняльно-історичний, які дозволяють вивчати спадкоємні зв’язки між різними ідеями; метод систематизації наукових ідей; метод інтерпретації фактологічних даних; метод прогностичного мислення з орієнтацією на прогноз якісного результату. Новизна дослідження полягає у розробці алгоритму реалізації рефлексивно-проєктної парадигми освіти та визначенні її базисних положень як акме-орієнтирів розвитку молоді покоління Z.

Ключові слова: теорія поколінь, соціально-психологічні особливості молоді покоління Z, алгоритм реалізації рефлексивно-проєктної парадигми освіти, базисні положення.
TD 2606 - Execução do Programa de Aquisição de Alimentos nos Municípios Brasileiros
Authors: Sambuichi Regina Helena Rosa , Almeida Ana Flávia Cordeiro de , Perin Gabriela , Moura Iracema Ferreira de , Alves Paulo Sergio Cândido
Published: February 2021

Com o objetivo de incentivar a agricultura familiar e promover a segurança alimentar e nutricional, o Programa de Aquisição de Alimentos (PAA) adquire produtos diretamente dos agricultores familiares e de suas organizações, para atender à população em situação de vulnerabilidade por meio da doação desses alimentos. Este estudo realizou uma análise quantitativa da execução do PAA no período de 2011 a 2018, buscando, principalmente, identificar fatores relacionados ao acesso dos municípios ao programa, além de analisar a sua focalização e suas potencialidades para auxiliar no enfrentamento aos desafios que se apresentam na atualidade. Os resultados mostraram que o programa beneficiou mais de 450 mil de agricultores familiares no período, adquirindo 2 milhões de toneladas de alimentos e conseguindo atingir beneficiários em cerca de 83% dos municípios brasileiros. A probabilidade de acesso foi maior para municípios com menor desenvolvimento econômico, menos urbanos, com mais agricultores familiares e pertencentes às regiões Norte e Nordeste, o que indica que o programa está tendo eficácia na sua focalização – atender prioritariamente às regiões mais carentes de desenvolvimento rural. Esses dados corroboram os estudos encontrados na literatura que apontam o PAA como um importante canal de comercialização para a agricultura familiar, capaz de promover o aumento da renda, a inclusão produtiva e a dinamização da economia local, além de contribuir para a segurança alimentar e nutricional. Dessa forma, acredita-se que o programa seja uma ferramenta relevante a ser utilizada como instrumento mitigador de efeitos negativos, nos âmbitos econômico e social, gerados pelas crises atuais. Observou-se, porém, uma expressiva diminuição dos recursos aplicados no PAA nos últimos anos, o que é preocupante, considerando-se a sua reconhecida relevância e capacidade de gerar benefícios. Reforça-se, portanto, a necessidade de ampliar o investimento de recursos no programa, neste e nos próximos anos, de forma a se garantir que ele possa atingir as suas finalidades e atuar adequadamente no combate aos atuais desafios.
Ground Vibrational State SiO Emission in the VLA BAaDE Survey
Authors: Dike V. , Morris M. R. , Rich R. M. , Lewis M. O. , Quiroga-Nuñez L. H. , Stroh M. C. , Trapp A. C. , Claussen M. J.
Published: February 2021

Using a subsample of the Bulge Asymmetries and Dynamical Evolution (BAaDE) survey of stellar SiO masers, we explore the prevalence and characteristics of 28SiO J = 1 − 0, v = 0 emission. We identify 90 detections of maser, thermal, or composite 28SiO J = 1 − 0, v = 0 emission out of approximately 13,000 candidate spectra from the National Science Foundation’s Karl G. Jansky Very Large Array (VLA). We find that the detected sources are likely asymptotic giant branch stars belonging to a bright, foreground Milky Way stellar disk population. For the 32 sources showing thermal components, we extract values for outflow velocity by fitting thermal line profiles. We find a range of circumstellar envelope expansion velocities, and compare to previously recorded OH and CO expansion velocities. This preliminary survey is already the largest study of stellar ground vibrational state SiO masers to date, and will be expanded to include the entire VLA BAaDE data set when data reduction for the 18,988 target sources is completed.
First Observations of an Ion Vortex in a Magnetic Hole in the Solar Wind by MMS
Authors: Wang G. Q. , Volwerk M. , Wu M. Y. , Hao Y. F. , Xiao S. D. , Wang G. , Liu L. J. , Chen Y. Q. , Zhang T. L.
Published: February 2021

The coronal heating region is able to generate mirror mode structures by ion mirror instabilities. Linear magnetic holes are believed to be the remnants of mirror mode structures, thus they are believed to be messengers from the coronal heating region. They can be convected to ∼9 au with the solar wind flow, indicating that a stabilizing mechanism is necessary to make the magnetic holes survive for such a long time. Here, we investigate a magnetic hole with a size of ∼6.7 ρ
i in the solar wind based on observations by the Magnetospheric Multiscale mission. The unprecedented high-resolution data enable us to reveal the existence of the ion vortex inside the structure for the first time. Such an ion vortex forms a ring-like current, which is consistent with the magnetic field depression. The self-consistent structure of the magnetic hole contributed by the ion vortex can help to further shed light on the mechanism of the long-term survival of magnetic holes in the astrophysical plasma.
NuSTAR Observation of Energy Release in 11 Solar Microflares
Authors: Duncan Jessie , Glesener Lindsay , Grefenstette Brian W. , Vievering Juliana , Hannah Iain G. , Smith David M. , Krucker Säm , White Stephen M. , Hudson Hugh
Published: February 2021

Solar flares are explosive releases of magnetic energy. Hard X-ray (HXR) flare emission originates from both hot (millions of Kelvin) plasma and nonthermal accelerated particles, giving insight into flare energy release. The Nuclear Spectroscopic Telescope ARray (NuSTAR) utilizes direct-focusing optics to attain much higher sensitivity in the HXR range than that of previous indirect imagers. This paper presents 11 NuSTAR microflares from two active regions (AR 12671 on 2017 August 21 and AR 12712 on 2018 May 29). The temporal, spatial, and energetic properties of each are discussed in context with previously published HXR brightenings. They are seen to display several “large flare” properties, such as impulsive time profiles and earlier peak times in higher-energy HXRs. For two events where the active region background could be removed, microflare emission did not display spatial complexity; differing NuSTAR energy ranges had equivalent emission centroids. Finally, spectral fitting showed a high-energy excess over a single thermal model in all events. This excess was consistent with additional higher-temperature plasma volumes in 10/11 microflares and  only with an accelerated particle distribution in the last. Previous NuSTAR studies focused on one or a few microflares at a time, making this the first to collectively examine a sizable number of events. Additionally, this paper introduces an observed variation in the NuSTAR gain unique to the extremely low livetime (<1%) regime and establishes a correction method to be used in future NuSTAR solar spectral analysis.
Formation of Massive Star Clusters by Fast H i Gas Collision
Authors: Maeda Ryunosuke , Inoue Tsuyoshi , Fukui Yasuo
Published: February 2021

Young massive clusters (YMCs) are dense aggregates of young stars, which are essential to galaxy evolution, owing to their ultraviolet radiation, stellar winds, and supernovae. The typical mass and radius of YMCs are M ∼ 104
M
⊙ and R ∼ 1 pc, respectively, indicating that many stars are located in a small region. The formation of YMC precursor clouds may be difficult because a very compact massive cloud should be formed before stellar feedback blows off the cloud. Recent observational studies suggest that YMCs can be formed as a consequence of the fast H i gas collision with a velocity of ∼100 km s−1, which is the typical velocity of the galaxy–galaxy interaction. In this study, we examine whether the fast H i gas collision triggers YMC formation using three-dimensional magnetohydrodynamics simulations, which includes the effects of self-gravity, radiative cooling/heating, and chemistry. We demonstrate that massive gravitationally bound gas clumps with M > 104
M
⊙ and L ∼ 4 pc are formed in the shock compressed region induced by the fast H i gas collision, in which massive gas clumps can evolve into YMCs. Our results show that the YMC precursors are formed by the global gravitational collapse of molecular clouds, and YMCs can be formed even in low-metal environments, such as the Magellanic Clouds. Additionally, the very massive YMC precursor cloud, with M > 105
M
⊙, can be created when we consider the fast collision of H i clouds, which may explain the origin of the very massive stellar cluster R136 system in the Large Magellanic Cloud.
Golden Galactic Binaries for LISA: Mass-transferring White Dwarf Black Hole Binaries
Authors: Sberna Laura , Toubiana Alexandre , Miller M. Coleman
Published: February 2021

We study the evolution and gravitational wave emission of white dwarf–black hole accreting binaries with a semianalytical model. These systems will evolve across the mHz gravitational wave frequency band and potentially be detected by the Laser Interferometer Space Antenna (LISA). We identify new universal relations for this class of binaries, which relate the component masses to the gravitational wave frequency and its first derivative. Combined with the high precision measurements possible with LISA, these relations could allow us to infer the component masses and the luminosity distance of the source. LISA has therefore the potential to detect and characterize a virtually unexplored binary population.
Baryonic Feedback Measurement From KV450 Cosmic Shear Analysis
Authors: Yoon Mijin , Jee M. James
Published: February 2021

While baryonic feedback is one of the most important astrophysical systematics that we need to address in order to achieve precision cosmology, few weak lensing studies have directly measured its impact on the matter power spectrum. We report measurement of the baryonic feedback parameter with the constraints on its lower and upper limits from cosmic shear. We use the public data from the Kilo-Degree Survey and the VISTA Kilo-Degree Infrared Galaxy Survey spanning 450 deg2. Estimating both cosmological and feedback parameters simultaneously, we obtain

A

b

=

1.01

−
0.85

+
0.80

, which shows a consistency with the dark matter-only (DMO) case at the ∼1.2σ level and a tendency toward positive feedback; the A
b = 0 (0.81) value corresponds to the DMO (OWLS AGN) case. Despite this full constraint of the feedback parameter, our

S

8

(
≡

σ

8

Ω

m

/

0.3

)

measurement (

0.739

−
0.035

+
0.036

) shifts by only ∼6% of the statistical error, compared to the previous measurement. When we assume the flat ΛCDM cosmology favored by the Nine-Year Wilkinson Microwave Anisotropy Probe (Planck) result, the feedback parameter is constrained to be

A

b

=

1.21

−
0.54

+
0.61

(

1.60

−
0.52

+
0.53

), which excludes the DMO case at the ∼2.2σ (∼3.1σ) level.
Whistlers in the Solar Vicinity That Are Spiky in Time and Frequency
Authors: Mozer F. S. , Bonnell J. W. , Halekas J. S. , Rahmati A. , Schum G. , Vasko I. V.
Published: February 2021

Spiky whistlers are short duration chirps of electric field that have fine structures in both frequency and time. They are observed on the Parker Solar Probe for the first time. From the limited available data, they appear to be accompanied by low-frequency ion waves and to occur relatively frequently. The origin of these wave pairs and their correlations are not understood.
Wave-driven Shocks in Stellar Outbursts: Dynamics, Envelope Heating, and Nascent Blast Waves
Authors: Matzner Christopher D. , Ro Stephen
Published: February 2021

We address the shocks from acoustic pulses and wave trains in general one-dimensional flows, with an emphasis on the application to super-Eddington outbursts in massive stars. Using approximate adiabatic invariants, we generalize the classical equal-area technique in its integral and differential forms. We predict shock evolution for the case of an initially sinusoidal but finite wave train, with separate solutions for internal shocks and head or tail shocks, and demonstrate detailed agreement with numerical simulations. Our internal shock solution motivates improved expressions for the shock-heating rate. Our solution for head and tail shocks demonstrates that these preserve dramatically more wave energy to large radii and have a greater potential for the direct ejection of matter. This difference highlights the importance of the waveform for shock dynamics. Our weak-shock analysis predicts when shocks will become strong and provides a basis from which this transition can be addressed. We use it to estimate the mass ejected by sudden sound pulses and weak central explosions.
Detection of GeV Gamma-ray Emission of Kepler’s SNR With Fermi-LAT
Authors: Xiang Yunchuan , Jiang Zejun
Published: February 2021

A likely detection of γ-ray emission from the region of Kepler’s Supernova Remnant (SNR) is reported by analyzing ∼12 yr of Pass 8 data of the Fermi Large Area Telescope. Its photon flux is (4.85 ± 0.60) × 10−10 ph cm−2 s−1 with ∼4σ significance in 0.2−500 GeV. Moreover, our results show that there is no significant variability in the light curve of ∼12 yr, and its position can well overlap with the observation result of Chandra in hard X-ray band with a good spatial resolution of 0.″5, so the source is likely to be the GeV γ-ray counterpart of Kepler’s SNR. The spectral energy distribution of γ-rays from Kepler’s SNR favors a hadronic origin in GeV band. Through analyzing multi-band data from radio to γ-ray and surveying the distribution from the surrounding CO molecules cloud, we found that if this γ-ray emission is from Kepler’s SNR, then it may originate from interactions between the relativistic protons escaping from the shock of Kepler’s SNR and surrounding CO gas molecules. However, more observation data are necessary to firmly confirm the association between the γ-ray source and Kepler’s SNR in the future.
On the Use of Field RR Lyrae as Galactic Probes. II. A New ΔS Calibration to Estimate Their Metallicity*
Authors: Crestani J. , Fabrizio M. , Braga V. F. , Sneden C. , Preston G. , Ferraro I. , Iannicola G. , Bono G. , Alves-Brito A. , Nonino M. , D’Orazi V. , Inno L. , Monelli M. , Storm J. , Altavilla G. , Chaboyer B. , Dall’Ora M. , Fiorentino G. , Gilligan C. , Grebel E. K. , Lala H. , Lemasle B. , Marengo M. , Marinoni S. , Marrese P. M. , Martínez-Vázquez C. E. , Matsunaga N. , Mullen J. P. , Neeley J. , Prudil Z. , Silva R. da , Stetson P. B. , Thévenin F. , Valenti E. , Walker A. , Zoccali M.
Published: February 2021

We performed the largest and most homogeneous spectroscopic survey of field RR Lyraes (RRLs). We secured ≈6300 high-resolution (HR, R ∼ 35,000) spectra for 143 RRLs (111 fundamental, RRab; 32 first-overtone, RRc). The atmospheric parameters were estimated by using the traditional approach and the iron abundances were measured by using an LTE line analysis. The resulting iron distribution shows a well-defined metal-rich tail approaching solar iron abundance. This suggests that field RRLs experienced a complex chemical enrichment in the early halo formation. We used these data to develop a new calibration of the ΔS method. This diagnostic, based on the equivalent widths of Ca ii K and three Balmer (H
δ,γ,β
) lines, traces the metallicity of RRLs. For the first time, the new empirical calibration: (i) includes spectra collected over the entire pulsation cycle; (ii) includes RRc variables; (iii) relies on spectroscopic calibrators covering more than three dex in iron abundance; and (iv) provides independent calibrations based on one/two/three Balmer lines. The new calibrations were applied to a data set of both SEGUE-SDSS and degraded HR spectra totalling 6451 low-resolution (R ∼ 2000) spectra for 5001 RRLs (3439 RRab, 1562 RRc). This resulted in an iron distribution with a median η = −1.55 ± 0.01 and σ = 0.51 dex, in good agreement with literature values. We also found that RRc are 0.10 dex more metal-poor than RRab variables, and have a distribution with a smoother metal-poor tail. This finding supports theoretical prescriptions suggesting a steady decrease in the RRc number when moving from metal-poor to metal-rich stellar environments.
A Backscattering-dominated Prompt Emission Model for the Prompt Phase of Gamma-Ray Bursts
Authors: Vyas Mukesh K. , Pe’er Asaf , Eichler David
Published: February 2021

As a gamma-ray burst (GRB) jet drills its way through the collapsing star, it traps a baryonic “cork” ahead of it. Here we explore a prompt emission model for GRBs in which the jet does not cross the cork, but rather photons that are emitted deep in the flow largely by pair annihilation are scattered inside the expanding cork and escape largely from the back end of it as they push it from behind. Due to the relativistic motion of the cork, these photons are easily seen by an observer close to the jet axis peaking at ε
peak ∼ few ×100 keV. We show that this model naturally explains several key observational features: (1) a high-energy power-law index β
1 − 2 to − 5 with an intermediate thermal spectral region; (2) decay of the prompt emission light curve as ∼ t
−2; (3) delay of soft photons; (4) a peak energy–isotropic energy (the so-called “Amati”) correlation,

ε

peak

∼

ε

iso

m

, with m ∼ 0.45, resulting from different viewing angles (at low luminosities, our model predicts an observable turnoff in the Amati relation); (5) an anticorrelation between the spectral FWHM and time as t
−1; (6) temporal evolution ε
peak ∼ t
−1; and (7) distribution of peak energies ε
peak in the observed GRB population. The model is applicable for single-pulse GRB light curves and their respective spectra. We discuss the consequences of our model in view of current and future prompt emission observations.
WOCS 5379: Detailed Analysis of the Evolution of a Post-mass-transfer Blue Straggler
Authors: Sun 孙 M. 萌 , Mathieu Robert D. , Leiner Emily M. , Townsend R. H. D.
Published: February 2021

The blue straggler binary WOCS 5379 is a member of the old (6–7 Gyr) open cluster NGC 188. WOCS 5379 comprises a blue straggler star with a white dwarf companion in a 120 day eccentric orbit. Combined with the orbital period, this helium white dwarf is evidence of previous mass transfer by a red giant. Detailed models of the system evolution from a progenitor main-sequence binary, including mass transfer, are made using the Modules for Experiments in Stellar Astrophysics. Both of the progenitor stars are evolved in the simulation. WOCS 5379 is well reproduced with a primary star of initial mass 1.19 M
⊙, whose core becomes the white dwarf. The secondary star initially is 1.01 M
⊙. The secondary finished receiving mass from the donor 300 Myr ago, having moved beyond the NGC 188 turnoff as a 1.20 M
⊙ blue straggler. The successful model has a mass-transfer efficiency of 22%. This nonconservative mass transfer is key to expanding the orbit fast enough to permit stable mass transfer. Even so, the mass transfer begins with a short unstable phase, during which half of the accreted mass is transferred. With increasing mass, the secondary evolves from a radiative core to a convective core. The final blue straggler interior is remarkably similar to a 2.1 Gyr old 1.21 M
⊙ main-sequence star at the same location in the H-R diagram. The white dwarf effective temperature is also reproduced, but the modeled white dwarf mass of 0.33 M
⊙ is smaller than the measured mass of 0.42 M
⊙.
Dust, Gas, and Metal Content in Star-forming Galaxies at z ∼ 3.3 Revealed with ALMA and Near-IR Spectroscopy
Authors: Suzuki Tomoko L. , Onodera Masato , Kodama Tadayuki , Daddi Emanuele , Hayashi Masao , Koyama Yusei , Shimakawa Rhythm , Smail Ian , Sobral David , Tacchella Sandro , Tanaka Ichi
Published: February 2021

We conducted submillimeter observations with the Atacama Large Millimeter/submillimeter Array (ALMA) of star-forming galaxies at z ∼ 3.3, whose gas-phase metallicities have been measured previously. We investigated the dust and gas contents of the galaxies at z ∼ 3.3 and studied the interaction of galaxies with their circumgalactic or intergalactic medium at this epoch by probing their gas mass fractions and gas-phase metallicities. Single-band dust continuum emission tracing dust mass and the relation between the gas-phase metallicity and gas-to-dust mass ratio were used to estimate the gas masses. The estimated gas mass fractions and depletion timescales are f
gas= 0.20–0.75 and t
dep= 0.09–1.55 Gyr. Although the galaxies appear to be tightly distributed around the star-forming main sequence at z ∼ 3.3, both quantities show a wider spread at a fixed stellar mass than expected from the scaling relation, suggesting a large diversity of fundamental gas properties in star-forming galaxies that apparently lie on the main sequence. When we compared gas mass fraction and gas-phase metallicity in star-forming galaxies at z ∼ 3.3 and at lower redshifts, star-forming galaxies at z ∼ 3.3 appear to be more metal poor than local galaxies with similar gas mass fractions. Using the gas regulator model to interpret this offset, we find that this can be explained by a higher mass-loading factor, suggesting that the mass-loading factor in outflows increases at earlier cosmic times.
Origin of Galactic Spurs: New Insight from Radio/X-Ray All-sky Maps
Authors: Kataoka Jun , Yamamoto Marino , Nakamura Yuki , Ito Soichiro , Sofue Yoshiaki , Inoue Yoshiyuki , Nakamori Takeshi , Totani Tomonori
Published: February 2021

In this study, we analyze giant Galactic spurs seen in both radio and X-ray all-sky maps to reveal their origins. We discuss two types of giant spurs: one is the brightest diffuse emission near the map’s center, which is likely to be related to Fermi bubbles (NPSs/SPSs, north/south polar spurs, respectively), and the other is weaker spurs that coincide positionally with local spiral arms in our Galaxy (LAS, Local Arm spur). Our analysis finds that the X-ray emissions, not only from the NPS but also from the SPS, are closer to the Galactic center by ∼5° compared with the corresponding radio emission. Furthermore, larger offsets of 10°–20° are observed in the LASs; however, they are attributed to different physical origins. Moreover, the temperature of the X-ray emission is kT ≃ 0.2 keV for the LAS, which is systematically lower than those of the NPS and SPS (kT ≃ 0.3 keV) but consistent with the typical temperature of Galactic halo gas. We argue that the radio/X-ray offset and the slightly higher temperature of the NPS/SPS X-ray gas are due to the shock compression/heating of halo gas during a significant Galactic explosion in the past, whereas the enhanced X-ray emission from the LAS may be due to the weak condensation of halo gas in the arm potential or star formation activity without shock heating.
Binary Planetesimal Formation from Gravitationally Collapsing Pebble Clouds
Authors: Nesvorný David , Li Rixin , Simon Jacob B. , Youdin Andrew N. , Richardson Derek C. , Marschall Raphael , Grundy William M.
Published: February 2021

Planetesimals are compact astrophysical objects roughly 1–1000 km in size, massive enough to be held together by gravity. They can grow by accreting material to become full-size planets. Planetesimals themselves are thought to form by complex physical processes from small grains in protoplanetary disks. The streaming instability (SI) model states that millimeter/centimeter-sized particles (pebbles) are aerodynamically collected into self-gravitating clouds that then directly collapse into planetesimals. Here we analyze ATHENA simulations of the SI to characterize the initial properties (e.g., rotation) of pebble clouds. Their gravitational collapse is followed with the PKDGRAV
N-body code, which has been modified to realistically account for pebble collisions. We find that pebble clouds rapidly collapse into short-lived disk structures from which planetesimals form. The planetesimal properties depend on the cloud’s scaled angular momentum,

l
=
L

/

(

MR

H

2

Ω
)

, where L and M are the angular momentum and mass, R
H is the Hill radius, and Ω is the orbital frequency. Low-l pebble clouds produce tight (or contact) binaries and single planetesimals. Compact high-l clouds give birth to binary planetesimals with attributes that closely resemble the equally sized binaries found in the Kuiper Belt. Significantly, the SI-triggered gravitational collapse can explain the angular momentum distribution of known equally sized binaries—a result pending verification from studies with improved resolution. About 10% of collapse simulations produce hierarchical systems with two or more large moons. These systems should be found in the Kuiper Belt when observations reach the threshold sensitivity.
Evaluation of the probiotic and postbiotic potential of lactic acid bacteria from artisanal dairy products against pathogens
Authors: Hussain Nazar , Tariq Muhammad , Saris Per Erik Joakim , Zaidi Arsalan
Published: February 2021

Introduction: Probiotic and postbiotic potential of thirty-two strains of lactic acid bacteria (LAB), obtained earlier from artisanal dairy sources in Pakistan, have been investigated against major multi-drug resistant (MDR) and food borne pathogenic bacteria.

Methodology: LAB strains were identified by 16S rRNA gene sequencing and their antibacterial activity was assessed by the microdilution method. Four LAB isolates, Weissella confusa PL6, Enterococcus faecium PL7, and Lactobacillus delbrueckii PL11 and PL13 were shortlisted. Their ability to degrade lactose and safety for human consumption in terms of hemolysis and antibiotic susceptibility were assessed in vitro. The antibacterial components in the cell-free supernatants (CFSs) of isolate cultures were characterized biochemically by HPLC.

Results: Acid neutralization but not protease treatment abolished the antibacterial activity of CFSs. Lactic, acetic and propionic acids were the main acids in the CFSs, and acid production peaked in the stationary phase of growth. The antibacterial activity of the LAB cultures resulted from secretion of organic acids that lowered the pH. The strains exhibited variable ability to degrade lactose and were non-hemolytic and susceptible to the most common antibiotics.

Conclusions: These LAB strains are probiotic candidates for further investigation of their postbiotic role in naturally preserving processed foods and for attenuation of lactose intolerance.
Experience of Mother in Taking Care of Children with Stunting at Majene Regency, Indonesia
Authors: Darwis Darwis , Abdullah Rukman , Amaliah Lili , Bohari Bohari , Rahman Nurdin
Published: February 2021

Health officials have the role and responsibility to provide a promotive, preventive, curative, and rehabilitative action for children who are stunted. However, in fact, the role will be taken over entirely by parents, especially the mother. Therefore, the mother's experience needs to be explored in order to know the extent of a mother's efforts in treating her child who is stunted. This research used a qualitative method with a phenomenological approach. Data were collected through deep interviews using a questionnaire that was prepared and then the researcher recorded the process of interview. The sampling technique used was purposive sampling then proceed with snowball sampling. Then, data would be analyzed using the thematic analysis method, mothers of children who were categorized as stunting did not have clear knowledge about stunting, perfomed exclusive breastfeeding for 6 months but breastfeeding was not optimal until the children are 2 years of age, complementary feeding was not balanced because it did not contain carbohydrate, protein and fat sources, families with incomes below the minimum income experience stunted their children. Husband's support to all participants was very good in overcoming health problems that occur in children, but her husband's support was very lacking in efforts to prevent children from experiencing stunting, mothers of children who were categorized as stunting had good personal hygiene behaviors in children
Flueggea acicularis (Phyllanthaceae), a narrow endemic species rediscovered in central China
Authors: Xu Songzhi , Gan Qiliang , Fu Lianzhong , Jiang Mingxi , Li Zhenyu
Published: February 2021

Flueggea acicularis(Phyllanthaceae) is endemic to the karst region of central China. Male specimens of this species were first collected in 1908. In 1989, female plants ofF. aciculariswere found for the first time, but misidentified as a new species. Throughout this period the male plants ofF. aciculariswere mismatched with female plants of other species, and male plants had not been collected since 1908. Then, in March, 2009, the authors rediscovered a wild population ofF. acicularisconsisting of both male and female plants in Wuxi county, Chongqing municipality, China. Based on field investigation and examination of specimens, we matched the correct female and male plants of this species for the first time since its initial publication a century ago. A complete and accurate morphological description, distribution, habitat and phenology of this species are also provided. Furthermore, the conservation status ofF. acicularisis assessed as “Near Threatened” (NT) according to the IUCN Red List criteria.
The geography of maternal mortality in early twentieth century England and Wales
Authors: Reid Alice
Published: February 2021

Avant son déclin majeur dans les années 1930, l’une des caractéristiques les plus frappantes de la mortalité maternelle en Angleterre et au pays de Galles était sa répartition géographique, avec des taux de décès pour 10 000 naissances beaucoup plus élevés dans le Nord et l’Ouest du pays que dans le Sud et l’Est. Les facteurs qui sous-tendent ce schéma n’ont jamais été systématiquement explorés; cet article propose des analyses cartographiques et des régressions à partir des données disponibles pour les comtés et les county boroughs affin d’étudier les impacts de la disponibilité en sages-femmes formées et non formées, et en médecins, de l’infection dans les zones urbaines et industrielles, de la mortalité générale et des problèmes d’enregistrement sur la géographie de la mortalité maternelle. Il apparaît que la structure industrielle, la mortalité générale ainsi que l’offre et la formation de sages-femmes étaient des variables explicatives importantes. L’article suggère également que des variations plus fines dans les services des sages-femmes ainsi que des différences locales dans la qualité de l’enregistrement des causes de décès pourraient aussi avoir affecté le modèle régional.
Militer dans le syndicalisme international, deux études de cas
Authors: Rombaldi Maurício
Published: February 2021

Cette étude vise à comprendre la relation entre le syndicalisme brésilien et international dans les secteurs de la métallurgie et des télécommunications. Elle analyse notamment les différentes phases d’internationalisation du Brésil des années 1980 à nos jours, ainsi que les conditions sociales ayant permis à des syndicalistes brésiliens d’accéder aux espaces internationaux. À cette fin, on observe les relations internationales développées par les organisations syndicales brésiliennes des deux secteurs et les trajectoires de militants qui sont arrivés à occuper des postes dans les fédérations internationales.
La crise sanitaire sonne-t-elle la fin de la sous-traitance dans l’industrie de la viande ?
Authors: Kahmann Marcus
Published: February 2021

Depuis quelques années déjà, les pouvoirs publics allemands sont alertés sur les « excès » de l’industrie de la viande. Le projet de loi relatif au renforcement de l’inspection du travail du 29 juillet 2020 marque, dans le contexte de la crise sanitaire, une rupture dans la méthode du gouvernement fédéral et augmente la contrainte pesant sur les entreprises du secteur. Il vise à renforcer le nombre de contrôles au travail et à interdire, dans les entreprises d’au moins 50 salarié·es, la sous-traitance et le travail intérimaire. Cette interdiction est susceptible de bousculer les pratiques d’emploi et d’impacter le modèle économique du secteur. Cet article vise à éclairer la genèse de ce projet de loi, qui a depuis été adoptée le 18 décembre 2020.