bluuebunny/crossref_metadata_2025 huggingface dataset:
ОСОБЛИВОСТІ РОБОТИ ТЕРМОКАТАЛІТИЧНОГО ДАВАЧА В СЕРЕДОВИЩІ ПРИРОДНОГО ГАЗУ
Authors: Шинкарук Х.М.  , Чеховський С.А.
Published: September 2020

В роботі детально розглянуто принцип роботи та особливості функціонування термокаталітичних давачів та наведено короткі відомості про їх розвиток. Враховуючи вимоги, яким повинен відповідати давач, вибрано для дослідження найбільш оптимальний.  Проведено експериментальні дослідження чутливості термокаталітичних давачів, з використанням природного газу різного складу, визначеного хроматографічним методом. Одержані результати свідчать про можливість застосування давачів в якості чутливих елементів для контролю якості природного газу. Вказані проблемні питання, пов'язані з нестабільністю сенсорів в процесі експлуатації. Встановлено що термокаталітичні давачі не можуть забезпечити  безперервний контроль якості газу тривалий період часу, оскільки в процесі експлуатації знижується його чутливість.
CALCULATION OSCILLATIONS OF VARIOUS ELEMENTS OF THE ELASTIC SYSTEM OF THE CENTER-FREE GRINDING MACHINE SASL 5AD
Authors: Джугурян Т.Г.  , Марчук В.І.  , Марчук І. В.
Published: September 2020

During the design of operations of centerless intermittent grinding of surfaces there is a need to identify the natural frequencies of oscillations of the elements of the technological system of grinding. The method of calculation of rigidity, vibration resistance and forced oscillations of the elements of the circular grinding machine is offered in the article. Carrying out of experimental researches of rigidity of elastic system of the SASL 5AD grinding machine. We conducted preliminary experimental studies to measure the oscillations of various elements of the elastic system of the SASL 5AD grinding machine in the horizontal plane by piezoelectric sensors during grinding with continuous and discontinuous circles with different geometric parameters.
ДИНАМІЧНА МОДЕЛЬ ПРОЦЕСУ ШЛІФУВАННЯ ПЕРЕРИВЧАСТИМИ КРУГАМИ
Authors: Марчук В.І.  , Гринюк С.В.  , Марчук І. В.  , Cачковська Л.
Published: September 2020

В роботі розглядається динамічна модель процесу шліфування переривчастими кругами як об’єкт управління. Динамічна модель переривчастого шліфування представляється у вигляді одномасової системи. В процесі шліфування спостерігається регенеративний ефект, який заключається в тому, що реакція пружної системи проявляється у вигляді зворотнього зв’язку з запізнення у часі. Цей ефект відіграє подвійну роль і значно ускладнює вивчення динаміки процесу шліфування, так як за зносу в процесі різання круг і деталь задіяні в регенеруючому зворотньому зв’язку. В результаті проведених досліджень отримуємо оптимальний розв’язок для об’єктивного представлення динаміки процесу переривчастого шліфування.
УДОСКОНАЛЕНИЙ МЕТОД ТА ПРИСТРІЙ ДЛЯ ВИМІРЮВАННЯ ЕЛЕКТРОПРОВІДНОСТІ І КОЕФІЦІЄНТА ТЕРМО-ЕРС ДЛЯ ТЕРМОЕЛЕКТРИЧНИХ МАТЕРІАЛІВ
Authors: Криницький О.С.  , Дакус С.В.
Published: September 2020

В роботі представлено огляд методів вимірювання електропровідності і коефіцієнта термо-ЕРС для термоелектричних матеріалів. Дані параметри визначають термоелектричну потужність для напівпровідникових матеріалів, які використовують для створення термоелектричних генераторів як альтернативних джерел енергії. Попри простоту методик вимірювання цих параметрів, їх практична реалізація пов'язана зі значними труднощами, що призводить до похибок результатів вимірювання і впливає на оцінку ефективності нових термоелектричних матеріалів. Запропоновано  удосконалений метод вимірювання параметрів термоелементів та розроблена конструкція пристрою для його  реалізації.
The competencies needed for digital transformation
Authors: Fonseca Patrick , Picoto Winnie Ng
Published: September 2020

Due to advanced technologies, companies currently face massive changes in their work. The ability to connect with and to satisfy their customers through software-based experiences is even more important. This study contributes to the literature by helping companies rethink their strategies on the development of competencies to respond to the challenges of the current digital transformation. It further contributes by identifying the digital competencies, which are important in the companies’ workplace environment of today. This study used a panel of 16 professionals to create an ordering rank according to the degree of importance of digital competencies. This ranking provides an updated overview of the challenge from the gap in digital competencies that has resulted from the digital transformation. We used the Delphi method to divide this process into two phases with two rounds. According to the results, the most important digital competencies are related with data analysis, use, and collaboration through digital technologies.
Báculo de Petrus Ramus e seu uso para medição de profundidade
Authors: Brito da Silva Francisco Hemerson , Pereira Ana Carolina Costa
Published: September 2020

A história da matemática oferece diversos recursos didáticos e estratégias para o ensino de matemática, contribuindo para a construção do conhecimento matemático. Dentre esses recursos disponíveis, destacam-se os instrumentos matemáticos contidos em antigos tratados, em particular, os situados nos séculos XVI e XVII. O Via Regia ad Geometriam é um desses textos, que foi publicado na língua latina em 1569, pelo francês Petrus Ramus, traduzido para o inglês e publicado por William Bedwell, em 1636. Esse documento, que trata da “arte de medir bem”, traz um instrumento utilizado por agrimensores da época, denominado de báculo. A descrição da fabricação e de diferentes situações de uso do báculo, para medição de distâncias (comprimentos) e alturas, é apresentado no capítulo nove do tratado. Em vista disso, o presente artigo tem a finalidade de apresentar os conhecimentos matemáticos com base em uma situação proposta por Petrus Ramus, para o uso de seu báculo, relacionada à medição de profundidade. Assim, utilizou-se uma metodologia qualitativa documental, a partir da tradução, compreensão (histórica e matemática) e discussão do excerto, que direcionaram a buscar potencialidades didáticas do uso do báculo para essa situação. No decorrer do estudo, percebeu-se que, para essa situação específica, o autor nomeia a profundidade de altura reversa (Eversa altitudo), ou seja, ele a considera como uma altura abaixo do solo, voltada para medição de poços, buracos fundos e rios. Com relação aos conceitos matemáticos advindos da aplicação dessa situação, percebe-se que perpendicularidade, paralelismo, propriedades do triângulo retângulo, semelhança de triângulos, dentre outros, são utilizados no manuseio do báculo e que ambos podem ser direcionados ao desenvolvimento de algumas habilidades da Base Nacional Comum Curricular (BNCC) no Ensino Fundamental. Entretanto, considera-se que, após uma medição real de uma profundidade, por meio do instrumento, outros conceitos podem ser percebidos e agregados às potencialidades didáticas, visando, assim, estabelecer uma articulação entre a história e o ensino de matemática.
A Neuroendocrine Therapeutic Approach with the Pineal Hormone Melatonin, Cannabidiol and Oxytocin (MCO regimen) in the Treatment of the Autism Spectrum disorders
Authors: Di Fede Giuseppe
Published: September 2020

After several years of researches to identify possible neurochemical alterations, at present it is known that autism is characterized and induced by at least three neuroendocrine deficiencies, involving the pineal function and the secretion of its most investigated hormone, melatonin (MLT), brain cannabinoid system, and the neurohypophyseal production of oxytocin (OT). Because of the fundamental role of MLT in sleep regulation, brain cannabinoid system in pleasure perception and control of anxiety, and OT in the affective life, these three neuroendocrine deficiencies might explain at least in part the symptomatology of autism. Therefore, autism-related neurochemical anomalies would involve the same main brain structures responsible for the conscious and the affective life, as well as for pleasure perception. On these bases, a preliminary study was performed to evaluate the influence of a progressive neuroendocrine. Substitutive treatment in autistic children. The study included 30 consecutive patients, by treating the first 12 subjects with the only MLT (100 mg/day in the dark period), the next 12 subjects with MLT plus cannabidiol. (CBD) (10 mg twice/day), and the remaining 6 subjects with MLT plus CBD plus OT (2 mg twice/day). All therapies were orally administered. MLT alone was mainly active in the treatment of sleep disorders. The association with CBD improved the control of anxiety. Finally, the further association with OT was also effective in improving the social and affective relationships. These preliminary results would suggest the possibility to treat the autism spectrum disorders by correcting their main neuroendocrine deficiencies through an exogenous administration.
Corona Virus: Endemic To Pandemic
Authors: D Shah Takshil
Published: September 2020

Coronaviruses (CoVs) are imperative pathogens for human and vertebrates which can affect primarily respiratory, gastrointestinal, hepatic and central nervous system of human, domestic animals, birds, bat, mouse and many other wild animals. According to the literature, the epidemiology reported the outburst evidence of Severe Acute Respiratory Syndrome (SARS) in 2002-2003 and the Middle East Respiratory Syndrome (MERS) in 2012 have established the infectious transmission from animalâ€toâ€human and humanâ€toâ€human and now the emerging pathogen is CoVs which was found anonymously in a patient suffering from pneumonia in Wuhan in December 2019 has drawn incredible care around the world.
Predictors of mortality in upper gastrointestinal bleeding in patients already hospitalized for another condition: a prospective study.
Authors: Ortega Suazo EJ , Jiménez Rosales R , Martínez Cara JG , Redondo Cerezo E
Published: September 2020

Introducción y objetivos: Los pacientes con HDA intrahospitalaria presentan una mayor tasa de mortalidad, sin embargo, las razones de este incremento no se han estudiado en profundidad. Nuestro objetivo es comparar pacientes con HDA que acuden de forma ambulatoria, con aquellos que presentan un episodio de HDA estando hospitalizados por otra causa; así como identificar predictores de mortalidad hospitalaria en este subgrupo de pacientes.

Material y métodos: Estudio prospectivo de pacientes con HDA (varicosa y no varicosa) tratados en el Hospital Universitario "Virgen de las Nieves" de 2013-2017. Se recolectaron datos clínicos, bioquímicos, procedimientos, datos de evolución intrahospitalaria (resangrado, mortalidad) y mortalidad diferida a los 6 meses.

Resultados: Se incluyeron 540 pacientes con HDA, 59 hospitalizados y 481 ambulatorios. Los primeros diferían de los segundos, en la tasa de mortalidad intrahospitalaria (42,1% vs 7,8%; P<0,001), resangrado (29,3% vs. 15,3%; P=0,014), AIMS65≥2 (25,6% vs. 13,7%; P=0,043), Puntuación ASA (3-4 86,4% vs. 65,5%; P<0,001), sangrado activo en la endoscopia (55,9% vs. 26,4%; P<0,001), tratamiento endoscópico (71,2% vs. 35,8%, P<0,001), transfusiones sanguíneas (5,42 vs. 2,48; P<0,001) y estancia hospitalaria (23,69 frente a 6,91 días; P<0,001). Los predictores independientes de mortalidad en los hospitalizados fueron ASA ≥3 (OR 7,8; IC del 95%: 2,089-29,143, P=0,002) y la necesidad de intervención endoscópica (OR 2,00; IC del 95%: 1,063-3,746, P=0,032).

Conclusiones: Los pacientes hospitalizados con un episodio de HDA tienen una mayor morbimortalidad siendo la clasificación ASA un claro predictor de mortalidad, tanto en pacientes con HDA varicosa como no varicosa.
Drug induced liver injury. An increasing pathology.
Authors: de Vicente Ortega A , Ayuso Carrasco CAB , Romero Moreno S , Arroyo Argüelles JM , Tercero Lozano M
Published: September 2020

La hepatotoxicidad es uno de los efectos adversos medicamentoso más frecuente y grave. Por ello, ha crecido el interés en detectarlos.

Exponemos dos casos de colestasis hepática por consumo de sustancias farmacológicas, con la clínica que presentaban, pruebas complementarias realizadas y evolución. Con ello, queremos resaltar la importancia de la sospecha clínica de esta entidad, la cual está en auge.

Como resultados y conclusión, es una entidad que requiere alta sospecha clínica, pudiendo presentarse de diversas formas y siendo difícil de identificar. Se realiza como diagnóstico de exclusión y se debe tener presente ya que está viéndose incrementada.
Relationship Application Of Professional Nursing Practice Models With The Level Of Working Satisfaction Of Nurses In The MPKP Room Of Lasinrang Pinrang Hospital
Authors: Muslimin  , Werna Nontji  , Burhanuddin Bahar  , Safruddin
Published: September 2020

Professional Nursing Practice Model (MPKP) is a method of comprehensive nursing care in providing quality nursing care. This study aims to investigate the correlation between the implementation of the professional nursing practice model and the work satisfaction rate of the working nurses at the MPKP room of the Regional Hospital of Lasinrang in Pinrang. The study is analytically observational with a cross-sectional design. The subject (n=124) are practicing nurses in the inpatient ward of Lasinrang Regional Hospital of Pinrang. The sample was selected employing a systematic random sampling technique. The data were obtained with a questionnaire distribution and observation checklist and the data were analyzed with univariate and bivariate measures. The chi-square test proves that the operand (p=0.000), pre-Competence (p=0.000), competence (p=0.000), competence case (p=0.164), and round (p=0.164) on the work satisfaction rate of the working nurses. This implies that there is a significant correlation the operand evaluation, pre-conference, post-conference, and the work satisfaction rate of the working nurses for the value of p<0.05 but no significant correlation between case competency evaluation as well as round and the work satisfaction of the nurses with p>0.05.
Relationship Between Work Loads And Working Conditions With Nursing Stress Levels In Intensive Care Unit
Authors: Siringoringo Edison , Andi Susilawani  , Lhamsyah
Published: September 2020

Nurse workload is all activities carried out by nurses while on duty in a nursing service unit. Working conditions include physical environment variables such as the distribution of working hours, physical conditions in the form of noise, regulations, and demands. Job stress is a condition of tension that causes an imbalance of physical and psychological conditions in employees sourced from individuals and organizations that affect the physical, psychological, behavior of employees. This research method uses analytic research, with a cross-sectional design. The population in this study were nurses on duty in the ICU. The sample in this study amounted to 36 respondents with a sampling technique using the total sampling method. Data is collected by using a questionnaire sheet. Analysis of the data used by using the Chi-Square test. In this study, the results were obtained that the workload was in the bad category of 20 respondents (55.6%) and the working conditions included in the category did not support as many as 22 respondents (61.1%) and the stress level in the moderate category there were 23 respondents (63, 9%). Based on the analysis that has been done using the Chi-Square test, there is a significant relationship between workload with stress levels with a value of P = 0.000 <0.05 and work conditions with nurses' stress levels with a value of P = 0.011 <0.05. There is a relationship between workload and working conditions with the stress level of nurses in the ICU. It is hoped that this research can be used as additional knowledge for the educational institutions of Stikes Panrita Husada Bulukumba.
Lipophilicity trends upon fluorination of isopropyl, cyclopropyl and 3-oxetanyl groups
Authors: Jeffries Benjamin , Wang Zhong , Troup Robert I , Goupille Anaïs , Le Questel Jean-Yves , Fallan Charlene , Scott James S , Chiarparin Elisabetta , Graton Jérôme , Linclau Bruno
Published: September 2020

A systematic comparison of lipophilicity modulations upon fluorination of isopropyl, cyclopropyl and 3-oxetanyl substituents, at a single carbon atom, is provided using directly comparable, and easily accessible model compounds. In addition, comparison with relevant linear chain derivatives is provided, as well as lipophilicity changes occurring upon chain extension of acyclic precursors to give cyclopropyl containing compounds. For the compounds investigated, fluorination of the isopropyl substituent led to larger lipophilicity modulation compared to fluorination of the cyclopropyl substituent.
The Effect of Transparency, Accountability and Commitment Organization on Budget Quality with Leadership Style as a Moderating Variables on Government of North Sumatera
Authors: Lubis Veby Zoraya Fikri , . Erlina , Fachrudin Khaira Amalia
Published: September 2020

This study aims to evaluate the effect of transparency, accountability, and organizational commitment on budget quality with leadership style as a moderating variable on Government of North Sumatera. The population in this study amounted to 51 OPDs in the Provincial Government of North Sumatra, with the sampling technique using saturated samples where all populations were sampled. This study's results indicate that transparency affects budget quality, accountability affects budget quality, and organizational commitment affects budget quality in the Provincial Government of North Sumatra. Meanwhile, leadership style cannot moderate the relationship between transparency and budget quality. Leadership style can moderate the relationship between accountability for budget quality, and leadership style cannot moderate the relationship between organizational commitment to budget quality on Government of North Sumatera.
Lip Shaving in Carcinoma Lower Lip and Reconstruction by Local Advancement Mucosal Flap Under Local Anesthesia: A Case Report
Authors: Mohammed Tareq , TB Mamoon , Islam Md Sirajul , Islam Md Aminul , Milki Farid Uddin , Rahman ASM Lutfur , Chowdhury Nazmul Hossain , Islam Md Ashraful
Published: September 2020

The lips are one of the most important features of the face; and are functionally and aesthetically very important. It serves as border of the oral commissure, provides access to oral cavity and contributes to oral competence. It is important for verbal expression and fundamental for facial expression and overall appearance of face1 . Excessive sun exposure and tobacco use, may develop cancer. The cancer can occur anywhere along the upper or lower lip, but is most common on the lower lip. Most lip cancers are squamous cell carcinomas. Surgery is the main stay of treatment and lip shave is an established modality for superficial lesion followed by reconstruction. Extensive surgery may be necessary for larger lesion. Careful planning and reconstruction can restore eating and speaking normally, and also achieve a satisfactory appearance after surgery. Evidence supports that the concept of lip reconstruction started as early as 1000 BC in the sacred texts of great Susruta, India2 . Lip mucosa is very special and it is recommended to reconstruct the surgical defect with lip tissue whenever possible, as any other tissue is never comparable or can replace the lip tissue3 . This is the example of this presented case.
Variation in Geotechnical Behavior of Bentonite-Soil Blends in the Salty Environment of Liner
Authors: Nath Hrithik
Published: September 2020

Waste management is one of the most critical issues in Bangladesh. Every day thousands of people are dumping their daily household wastes in some specific dumping sites. The leachate that is being generated from these wastes is changing the quality of the soil by mixing with the surrounding soil and is also contaminating the groundwater. Several components such as water and different varieties of salt are found in the leachate. This paper represents the findings of a recent study on the effect of inorganic NaCl salt on certain geotechnical properties of clay soil mixed with bentonite used as a liner material. The clay soil was collected from a local household waste dump in the Khanabari area of Khulna district. The soil was mixed with different percentages of bentonite (10% & 20%) to test the effect of various concentrations (0M, 0.1M & 1M) of inorganic salt. For this reason, laboratory tests like compaction test, liquid limit test, 1-D consolidation test, permeability test, free swell test and pH test were performed. Finally, it was concluded that a salty environment could have a significant effect on the mixture's geotechnical characteristics.
BACKPRESSURE BASED TRAFFIC SIGNAL CONTROL CONSIDERING CAPACITY OF DOWNSTREAM LINKS
Authors: Hao Shenxue , Yang Licai , Shi Yunfeng , Guo Yajuan
Published: September 2020

Congestion is a kind of expression of instability of traffic network. Traffic signal control keeping traffic network stable can reduce the congestion of urban traffic. In order to improve the efficiency of urban traffic network, this study proposes a decentralized traffic signal control strategy based on backpressure algorithm used in Wi-Fi mesh networks for packets routing. Backpressure based traffic signal control algorithm can stabilize urban traffic network and achieve maximum throughput. Based on original backpressure algorithm, the variant parameter and penalty function are considered to balance the queue differential and capacity of downstream links in urban traffic network. For each traffic phase of intersections, phase weight is computed using queue differential and capacity of downstream links, which fixed the deficiency of infinite queue capacity in original backpressure algorithm. It is proved that the extended backpressure traffic signal control algorithm can maintain stability of urban traffic network, and also can prevent queue spillback, so as to improve performance of whole traffic network. Simulations are carried out in Vissim using Vissim COM programming interface and Visual Studio development tools. Evaluation results illuminate that it can get better performance than the backpressure algorithm just based on queue length differential in average queue length and delay of traffic network.
Exploring the Mass-loss Histories of the Red Supergiants*
Authors: Humphreys Roberta M. , Helmel Greta , Jones Terry J. , Gordon Michael S.
Published: September 2020

We report mid- to far-infrared imaging and photometry from 7 to 37 μm with SOFIA/FORCAST and 2 μm adaptive optics imaging with LBTI/LMIRCam of a large sample of red supergiants (RSGs) in four Galactic clusters: RSGC1, RSGC2 = Stephenson 2, RSGC3, and NGC 7419. The RSGs in these clusters cover their expected range in luminosity and initial mass from ≈9 to more than 25 M
⊙. The population includes examples of very late-type RSGs such as MY Cep, which may be near the end of the RSG stage, high-mass-losing maser sources, yellow hypergiants, and post-RSG candidates. Many of the stars and almost all of the most luminous have spectral energy distributions (SEDs) with extended infrared excess radiation at the longest wavelengths. To best model their SEDs, we use the DUSTY code with a variable radial density distribution function to estimate their mass-loss rates. Our

–luminosity relation for 42 RSGs basically follows the classical de Jager curve, but at luminosities below 105

, we find a significant population of RSGs with

below the de Jager relation. At luminosities above 105
L
⊙, there is a rapid transition to higher mass-loss rates that approximates and overlaps the de Jager curve. We recommend that instead of using a linear relation or single curve, the empirical

–luminosity relation is better represented by a broad band. Interestingly, the transition to much higher

at about 105
L
⊙ corresponds approximately to an initial mass of 18–20 M
⊙, which is close to the upper limit for RSGs becoming Type II supernovae.
Multiple Explanations for the Single Transit of KIC 5951458 Based on Radial Velocity Measurements Extracted with a Novel Matched-template Technique∗
Authors: Dalba Paul A. , Fulton Benjamin , Isaacson Howard , Kane Stephen R. , Howard Andrew W.
Published: September 2020

Planetary systems that show single-transit events are a critical pathway to increasing the yield of long-period exoplanets from transit surveys. From the primary Kepler mission, KIC 5951458 b (Kepler-456b) was thought to be a single-transit giant planet with an orbital period of 1310 days. However, radial velocity (RV) observations of KIC 5951458 from the HIRES instrument on the Keck telescope suggest that the system is far more complicated. To extract precise RVs for this

star, we develop a novel matched-template technique that takes advantage of a broad library of template spectra acquired with HIRES. We validate this technique and measure its noise floor to be 4–8 m s−1 (in addition to internal RV error) for most stars that would be targeted for precision RVs. For KIC 5951458, we detect a long-term RV trend that suggests the existence of a stellar companion with an orbital period greater than a few thousand days. We also detect an additional signal in the RVs that is possibly caused by a planetary or brown dwarf companion with mass in the range of 0.6–82 M
Jup and orbital period below a few thousand days. Curiously, from just the data on hand, it is not possible to determine which object caused the single “transit” event. We demonstrate how a modest set of RVs allows us to update the properties of this unusual system and predict the optimal timing for future observations.
HD 62542: Probing the Bare, Dense Core of a Translucent Interstellar
Cloud*
Authors: Welty Daniel E. , Sonnentrucker Paule , Snow Theodore P. , York Donald G.
Published: September 2020

We discuss the interstellar absorption from many atomic and molecular species
seen in high-resolution Hubble Space Telescope/STIS UV and high signal-to-noise
ratio optical spectra of the moderately reddened B3–5 V star HD 62542. This
remarkable sight line exhibits both very steep far-UV extinction and a high
fraction of hydrogen in molecular form, with strong absorption from CH,
C2, CN, and CO, but weak absorption from CH+ and most
of the commonly observed diffuse interstellar bands. Most of the material
resides in a single narrow velocity component, offering a rare opportunity to
probe the primarily molecular core of a single interstellar cloud with little
associated diffuse atomic gas. Detailed analyses of the spectra indicate that
(1) the molecular fraction in the main cloud is high
(f(H2) ≳ 0.8); (2) the gas is fairly cold
(T
k = 40–43 K; from the rotational excitation of
H2 and C2); (3) the local hydrogen density
n
H ∼ 1500 cm−3 (from C2
excitation, fine-structure excitation of C0, and simple chemical
models); (4) the unusually high excitation temperatures for 12CO and
13CO may be largely due to radiative excitation; (5)
N(C+):N(CO):N(C) ∼ 100:10:1;
(6) the depletions of many elements are more severe than those seen in any other
sight line and the detailed pattern of depletions differs from those derived
from larger samples of Galactic sight lines; and (7) the various neutral/first
ion ratios do not yield consistent estimates for electron density, even when the
effects of grain-assisted recombination and low-temperature dielectronic
recombination are considered.
A New Spin on an Old Black Hole: NuSTAR Spectroscopy of EXO 1846–031
Authors: Draghis Paul A. , Miller Jon M. , Cackett Edward M. , Kammoun Elias S. , Reynolds Mark T. , Tomsick John A. , Zoghbi Abderahmen
Published: September 2020

The black hole candidate EXO 1846-031 underwent an outburst in 2019, after at least 25 yr in quiescence. We observed the system using NuSTAR on 2019 August 3. The 3–79 keV spectrum shows strong relativistic reflection features. Our baseline model gives a nearly maximal black hole spin value of

(1σ statistical errors). This high value nominally excludes the possibility of the central engine harboring a neutron star. Using several models, we test the robustness of our measurement to assumptions about the density of the accretion disk, the nature of the corona, the choice of disk continuum model, and the addition of reflection from the outer regions of the accretion disk. All tested models agree on a very high black hole spin value and a high value for the inclination of the inner accretion disk of

. We discuss the implications of this spin measurement in the population of stellar mass black holes with known spins, including LIGO and Virgo events.
Awakening of Two Gamma-Ray High-redshift, Flat-spectrum Radio Quasars in the Southern Hemisphere
Authors: Li Shang , Sun Lu-Ming , Liao Neng-Hui , Fan Yi-Zhong
Published: September 2020

High-redshift blazars are valuable tools to study the early universe. So far, only a handful of γ-ray blazars have been found at redshifts above 3. Gamma-ray signals are detected in the direction of PMN J2219–2719 (z = 3.63) and PMN J2321–0827 (z = 3.16) by analyzing the 10 yr Fermi-LAT Pass 8 data. PMN J2219–2719 is not distinguished from the background in the global analysis. During the 5 month epoch, the TS value is 47.8 and the flux is more than 10 times that of the 10 yr averaged flux. In addition, the angular distance between the γ-ray position and the radio position of PMN J2219–2719 is only 0.°04. Moreover, the long timescale γ-ray and infrared light curves are very similar, which supports the association between the γ-ray source and PMN J2219–2719. The global analysis of PMN J2321–0827 suggest a new γ-ray source; during the flare phase, the TS value is 61.4 and the γ-ray flux increased significantly. The association probability suggests that PMN J2321–0827 may be the counterpart of the new γ-ray source. In the future, the number of high-redshift γ-ray sources will increase by combining Fermi-LAT and the upcoming Large Synoptic Survey Telescope.
Multi-frequency General Relativistic Radiation-hydrodynamics with M1 Closure
Authors: Anninos Peter , Fragile P. Chris
Published: September 2020

We report on recent upgrades to our general relativistic radiation-magnetohydrodynamics code, Cosmos++, which expands the two-moment, 
M

1, radiation treatment from gray to multi-frequency transport, including Doppler and gravitational frequency shifts. The solver accommodates either photon (Bose–Einstein) or neutrino (Fermi–Dirac) statistical distribution functions with absorption, emission, and elastic scattering processes. An implicit scheme is implemented to simultaneously solve the primitive inversion problem together with the radiation–matter coupling source terms, providing stability over a broad range of opacities and optical depths where the interaction terms can be stiff. We discuss our formulations and numerical methods, and validate our methods against a wide variety of test problems spanning optically thin to thick regimes in flat, weakly curved, and strongly curved spacetimes.
Optimal fishing mortality assignment for southern hake Merluccius australis in Chile
Authors: Lopez Felipe , Jimenez Jorge , Canales Cristian
Published: September 2020

Since 1979, southern hake (Merluccius australis) has been exploited in Chile from the Bio Bio to the Magallanes regions, between the parallels 41°28.6'S and 57°S. There is evidence of a constant fishing effort and a sustained reduction of the fish population, consistent with a progressive decrease in total annual catches. Management strategies based on the maximum sustainable yield (MSY) and quota assignment/ distribution criteria have not been able to sustain acceptable biomass levels. A non-linear optimization model with two objective functions was proposed to determine an optimal total catch quota for more sustainable exploitation of this fishery. The first function maximizes the total catch over time in response to an optimal assignment of fishing mortality rates per fleet; the second function maximizes the total economic benefit associated with the total catch. The dynamics of the fish population were represented with the equations of a predictive age-structured model. Decision variables were fishing mortality rates and annual catch quotas per fleet, subject to constraints that guarantee a minimum level of biomass escape over a long-term period. The input parameters were obtained from the last stock evaluation report carried out by the Instituto de Fomento Pesquero (IFOP) of Chile. The historical background data of the fishery and the regulatory framework were relevant aspects of the methodology. Five scenarios were evaluated with the two objective functions, including a base scenario, which considered the referential mortality rate as input data as the average mortality rate per fleet from 2007 to 2012. Total economic benefits fluctuate between 102 and USD 442 million for total catches in the range of 108 to 421 thousand tons, which were obtained from maximizing the economic and biological objective functions. Economic benefit/catch ratios were reduced for scenarios with higher constraints on catch limits, and they were more efficient from a biological point of view. Situations with lighter constraints showed in general higher economic benefits and better performance ratios than those with stronger restrictions. The use of optimization models may provide a useful tool to evaluate the effect of regulations for adequate conservation and economical utilization of a limited resource.
Length-based indicators for the management of sport fishery in Yucatan, Mexico
Authors: López-Rocha Jorge A. , Vidal-Hernández Laura , Bravo-Calderón Arturo
Published: September 2020

Sportfishing is an activity of increasing popularity that involves a large number of users and high levels of fishing effort. In Yucatan, most of the target species in sport fishing are the same as those of commercial fisheries. However, there is no record of fishing effort or catch volumes. Thus the impact of sport fishing on these populations is unknown. This study analyzes the catches made by users of sport fisheries of nine species (Epinephelus morio, Haemulon plumieri, Seriola dumerili, Lutjanus synagris, Ocyurus chrysurus, Calamus bajonado, Sphyraena barracuda, S. guachancho and Mycteroperca bonaci) through length-based indicators. Samples of species’ sizes were obtained from the catches made during 10 fishing tournaments held in Yucatan's three-port towns (Sisal, Yucalpeten, and Telchac) between 2015 and 2016. The catch variables that were evaluated included: the number of mature individuals Pmat, optimal length Popt, and the number of mega-spawners Pmega. Length measures were derived from 1,252 individuals. Only H. plumieri, L. synagris, and S. guachancho exhibited sustainable indicator values, while E. morio and C. bajonado demonstrated extremely low values. In most species, sport fishing affects a high proportion of juveniles. The results suggest that sportfishing contributes to the fishing pressure of a species and commercial fishing, due to the capture of juveniles of economically important fish. It is essential to establish a systematic monitoring method of such activities and increase the priority level of the evaluation and management of this fishery.
Feeding habits variability of Lutjanus synagris and Lutjanus griseus in the littoral of Campeche, Mexico: an approach of food web trophic interactions between two snapper species
Authors: Juárez-Camargo Paloma G. , Sosa-López Atahualpa , Torres-Rojas Yassir Edén , Mendoza-Franco Edgar Fernando , Aguiñiga García Sergio
Published: September 2020

The study of the feeding habits variability (spatial and temporal scales) allows us to evaluate the trophic interactions between species, thus, the short and long-term effects of the removal of different species by the presence of different phenomena. In this study, we carried out stable isotope (δ13C and δ15N) and stomach content analyses to infer the trophic linkages between two snapper species (Lutjanus synagris and Lutjanus griseus) captured in the littoral of Campeche, Mexico. In total, 781 specimens were collected (528 L. synagris and 253 L. griseus) and based on relative importance index [%PSIRI] both snapper species consumed based on the prey-specific index of relative importance (PSIRI), Penaeidae family (PSIRI = 23.41%) was the most important species in the diet of Lutjanus synagris, while Callinectes sapidus (PSIRI = 21.45%) was the primary prey of Lutjanus griseus. The isotopic analyses indicated that both snapper species feed in the coastal-marine (δ15N: 10.6 to 12.1‰ and δ13C: -15.7 to -12.7‰); however, according to PERMANOVA, low diet similarity was found between snapper species (R = 0.07, P < 0.01), also, significant differences was detected in the δ15N and δ13C values between L. synagris, and L. griseus. Therefore, despite both snapper species presents similar trophic positions (L. synagris: 4.2 ± 0.2; L. griseus: 3.9 ± 0.1) and feeding behavior (according to SIBER = opportunistic predators), a low trophic overlap was observed, probably associated with the differential use of habitat in the coastal zone; where L. synagris is ecologically fed in areas of seagrass, while L. griseus is probably intermittent between pasture and mangrove areas, therefore, the role of each species is crucial in the dynamics of coastal-marine ecosystems as predators and potential structuring of the populations of their prey.
First confirmed record of the occurrence of the lesser devil ray, Mobula hypostoma (Elasmobranchii, Mobulidae), in the southwestern Gulf of Mexico
Authors: Del Moral-Flores Luis Fernando , Meza-Abundio Itzel , Pérez-España Horacio
Published: September 2020

Nine specimens (one female and eight males, all juveniles) of lesser devil ray, Mobula hypostoma (Bancroft, 1831), were caught in the southwest Gulf of Mexico. These specimens represent the first record of the species in the Mexican waters. The disk width ranged between 552 and 773 mm. Morphometrics data are consistent with previously published records. Because of the number of specimens captured, we suggest that it is not a rare species in the southwest Gulf of Mexico.
Seasonal variability of near-surface zooplankton community structure in the southern Gulf of Mexico
Authors: Cruz-Rosado Leonardo , Contreras-Sánchez Wilfrido M. , Hernández-Vidal Ulises , Gómez-Gutiérrez Jaime , Contreras-García María de Jesús , Mcdonal-Vera Alejandro
Published: September 2020

The zooplankton taxonomic group composition was analyzed in a known spawning area for snooks of the family Centropomidae during March 2011-February 2012 near the González River's mouth, a tributary of the Grijalva-Usumacinta River system, discharging into the southern Gulf of Mexico. Zooplankton was collected near the surface using three distinct zooplankton nets (20, 64, and 120 μm). Sixteen zooplankton taxonomic groups were collected between the three nets. Copepoda (76.9%), Trematoda (6.7%), Bivalvia (4.6%), and Chaetognatha (Sagittoidea 4.3%) numerically dominated zooplankton community structure. The 120 and 64 μm nets collected the highest diversity of zooplankton (15 taxa). Zooplankton was more abundant during June-October (summer storm season). They associated with lower salinities (due to the increase in the discharge volume of the Grijalva-Usumacinta River system) and higher regional primary productivity than observed during the rest of the year (March-May, dry season, and November-February, winter storm season). The highest peak of zooplankton abundance was found in November during the beginning of winter storms. Nine taxonomic groups were observed frequently and abundantly during the summer storm season, while only five taxonomic groups were abundant during the dry season.
Caracterização morfológica e fisiológica de leveduras submetidas à preservação prolongada por congelamento a -80ºC e liofilização
Authors: Has Murilo , Facco Laura Neves , Rosa Monique De Paula , Pietrowski Giovana De Arruda Moura
Published: September 2020

Leveduras do gênero Hanseniaspora são reconhecidas por sua contribuição aromática para sidras, fermentados de frutos e vinhos. Para uma boa preservação das culturas de leveduras é essencial manter as propriedades morfológicas e fisiológicas das estirpes, independentemente do método de armazenamento escolhido. O congelamento a -80ºC e a liofilização são métodos muito utilizados para preservação de microrganismos a longo prazo. O presente trabalho teve como objetivo avaliar as características fisiológicas e morfológicas de duas estirpes de leveduras utilizadas na indústria de bebidas fermentadas (Hanseniaspora uvarum e Hanseniaspora guilliermondii), submetidas à conservação prolongada por congelamento a -80°C e liofilização, verificando a eficácia desses métodos de preservação. As recuperações das cepas foram realizadas em dois períodos distintos, sendo realizado teste ecométrico do meio de cultura usado na replicação e manutenção das cepas, avaliações morfológicas de crescimento em meio sólido e líquido, avaliações bioquímicas envolvendo fermentações de carboidratos e testes de assimilação de diversos compostos. Os resultados evidenciaram a seletividade do meio de cultura Ágar Malte Extrato de Levedura (YMA) para as cepas estudadas. No perfil bioquímico a avaliação das cepas evidenciou diferenças na capacidade de fermentar a glicose e outros açúcares como também na assimilação de citrato, nitrato e hidrólise do amido, entretanto, as demais avaliações bioquímicas não sofreram variações quando comparadas à dados da literatura. Portanto, as características morfológicas e fisiológicas das cepas de leveduras estudadas, após sofrerem preservação a longo prazo, permanecem viáveis, proporcionando o uso dessas estirpes para a produção de compostos aromáticos em bebidas fermentadas. Além disso, a pesquisa ressalta o benefício da utilização tanto do congelamento a -80ºC quanto da liofilização para a manutenção de H. uvarum e H. guilliermondii por longos períodos.
Tracking the spread of the northern bark beetle (Ips duplicatus [Sahlb.]) in Europe and first records from Switzerland and Liechtenstein
Authors: Wermelinger Beat , Schneider Mathis Doris , Knížek Miloš , Forster Beat
Published: September 2020

The northern bark beetle (Ips duplicatus), in Europe originally restricted to northern countries, expanded its distribution range to eastern Europe in the 20th century and is now causing considerable damage in spruce forests. In the past decades its presence has been confirmed in several Central European countries.

By means of pheromone traps and visual inspection of infested logs, in this study we demonstrate that I. duplicatus is also present in the Rhine valley in Switzerland and Liechtenstein. Breeding galleries with beetles and exit holes in an infested spruce log indicate that the trapped beetles had successfully developed in a local stand nearby.

An inquiry addressed to European entomologists was carried out to obtain information and references concerning the year of the first record or mention of I. duplicatus in their respective countries. This information substantiated the expansion of its historical range to the southeast in the middle of the last century and clearly showed recent movement westward, with Switzerland and Germany currently the westernmost countries where this species occurs. This recent range expansion is likely attributed to the transport of infested timber. The economic significance of this expanding bark beetle species is discussed in view of its co-occurrence with the notorious pest species I. typographus.
An Author’s Editor Reads the “Instructions for Authors”
Authors: Lang Thomas A
Published: September 2020

I’ve been a medical writer and author’s editor for 45 years. I have read the instructions for authors in dozens of medical journals. I know what authors (and author’s editors) think of these instructions, at least among those who know that journals actually have instructions for authors. For almost as long, I’ve been a member of four professional societies concerned with scientific publishing, and I know a lot of editors-in-chief of medical journals. I appreciate their desire to have authors follow the instructions when preparing manuscripts, at least among those editors who remember that their journals have such instructions and insist, at least occasionally, that they be followed.
An International Nursing Student Exchange Program: An Educational Experience that Enhanced Student Cognitive Development
Authors: Frisch Noreen C
Published: September 2020

ABSTRACT

Increased attention to international nursing has lead to the development of study abroad programs for students. Participants in such programs describe the experiences as positive; however, studies of measured impact have not been reported. Student development theory provides an objective perspective from which to assess the level of cognition of undergraduate students and permits assessment of change in students' thinking maturity over time. This study documents the change of senior students' levels of cognition over one academic semester. Results indicate that those who participated in an international student nurse exchange program demonstrated significantly more growth than those who did not. As nursing moves to a global perspective, the author recommends similar evaluation of all such exchange programs.
Sertulum Ternstroemiacearum I. Sinopsis del género Freziera (Ternstroemiaceae) en Venezuela, incluyendo una especie nueva de la Cordillera de Mérida
Authors: Grande Allende José
Published: September 2020

El género Freziera Willd. se encuentra distribuido en Venezuela a lo largo de los sistemas montañosos de Los Andes, la Cordillera de la Costa y el Escudo Guayanés. Dos de las 11 especies conocidas del país son endémicas y podrían encontrarse amenazadas, pero su estado real de conservación se desconoce, correspondiendo a la categoría Datos Deficientes de acuerdo con los criterios de la UICN. En el presente trabajo se ofrece por primera vez una clave para todas las especies presentes en el país y se describe e ilustra Freziera polita A.L.Weitzman ex J.R.Grande, sp. nov., una especie restringida a la Cordillera de Mérida. Los caracteres diagnósticos de la nueva especie, la cual es muy similar a F. Guaramacalana D.Santam. & Cuello, incluyen pecíolos alargados, hojas maduras subglabras y corolas (en antesis) exertas menos de la mitad del largo de los sépalos.