bluuebunny/crossref_metadata_2025 huggingface dataset:
Vegetation change across the Drake Passage region linked to late Eocene cooling and glacial disturbance after the Eocene–Oligocene Transition
Authors: Thompson Nick , Salzmann Ulrich , López-Quirós Adrián , Bijl Peter K. , Hoem Frida S. , Etourneau Johan , Sicre Marie-Alexandrine , Roignant Sabine , Hocking Emma , Amoo Michael , Escutia Carlota
Published: July 2021

Abstract. The role and climatic impact of the opening of the Drake Passage and how it affected both marine and terrestrial environments across the Eocene-Oligocene Transition (EOT ~ 34 Ma) period remains poorly understood. Here we present new terrestrial palynomorph data compared with recently compiled lipid biomarker (n-alkane) data from Ocean Drilling Program (ODP) Leg 113 Site 696 drilled on the margin of the South Orkney Microcontinent in the Weddell Sea, to investigate changes in terrestrial environments and paleoclimate across the late Eocene and early Oligocene (~ 37.6–32.2 Ma). Early late Eocene floras and sporomorph-based climate estimates reveal Nothofagus-dominated forests growing under wet temperate conditions, with mean annual temperature (MAT) and precipitation (MAP) around 13 °C and 1660 mm, respectively. A phase of latest Eocene terrestrial cooling at 35.5 Ma reveals a decrease in MAT by around 2 °C possibly linked to the opening of the Powell Basin. This is followed by an increase in Mesozoic sporomorphs together with a shift in terrestrial biomarkers and sedimentological evidence indicating ice expansion to coastal and shelf areas approximately 34.1 million years ago. However, major changes to the terrestrial vegetation at Site 696 did not take place until the early Oligocene, where there is a distinct expansion of gymnosperms and cryptogams accompanied by a rapid increase in taxa diversity following 33.5 Ma. This unusual expansion of gymnosperms and cryptogams is suggested to be linked to environmental disturbance caused by repeat glacial expansion and retreat, which facilitated the expansion of conifer and ferns. We conclude that the timing of glacial onset rather suggests that the event at site 696 is linked to the global cooling at the EOT and that latest Eocene regional cooling cannot directly be linked. Therefore, confirming that the opening of ocean gateways alone did not trigger Antarctic glaciation, even if ocean gateways may have played a role in stepwise cooling before the EOT.
A new methodological framework by geophysical sensors combinations associated with machine learning algorithms to understand soil attributes
Authors: Mello Danilo César de , Veloso Gustavo Vieira , Lana Marcos Guedes de , Mello Fellipe Alcantara de Oliveira , Poppiel Raul Roberto , Cabrero Diego Ribeiro Oquendo , Di Raimo Luis Augusto Di Loreto , Schaefer Carlos Ernesto Gonçalves Reynaud , Filho Elpídio Inácio Fernandes , Leite Emilson Pereira , Demattê José Alexandre Melo
Published: July 2021

Abstract. Geophysical sensors combined with machine learning algorithms have been used to understand the pedosphere system, landscape processes and to model soil attributes. In this research, we used parent material, terrain attributes and data from geophysical sensors in different combinations, to test and compare different and novel machine learning algorithms to model soil attributes. Also, we analyzed the importance of pedoenvironmental variables in predictive models. For that, we collected soil physico-chemical and geophysical data (gamma-ray emission from uranium, thorium and potassium, magnetic susceptibility and apparent electric conductivity) by three sensors, gamma-ray spectrometer – RS 230, susceptibilimeter KT10 – Terraplus and Conductivimeter – EM38 Geonics) at 75 points and, we performed soil analysis afterwards. The results showed varying models with the best performance (R2 > 0.2) for clay, sand, Fe2O3, TiO2, SiO2 and Cation Exchange Capacity prediction. Modeling with selection of covariates at three phases (variance close to zero, removal by correction and removal by importance), demonstrated to be adequate to increase the parsimony. The prediction of soil attributes by machine learning algorithms demonstrated adequate values for field collected data, without any sample preparation, for most of the tested predictors (R2 ranging from 0.20 to 0.50). Also, the use of four regression algorithms proved important, since at least one of the predictors used one of the tested algorithms. The performances of the best algorithms for each predictor were higher than the use of a mean value for the entire area comparing the values of Root Mean Square Error (RMSE) and Mean Absolute Error (MAE). The best combination of sensors that reached the best model performance to predict soil attributes were gamma-ray spectrometer and susceptibilimeter. The most important variables were parent material, digital elevation model, standardized height and magnetic susceptibility for most predictions. We concluded that soil attributes can be efficiently modelled by geophysical data using machine learning techniques and geophysical sensors combinations. The technique can bring light for future soil mapping with gain of time and environment friendly.
Geophysical constraints on the properties of a subglacial lake in northwest Greenland
Authors: Maguire Ross , Schmerr Nicholas , Pettit Erin , Riverman Kiya , Gardner Christyna , DellaGiustina Daniella N. , Avenson Brad , Wagner Natalie , Marusiak Angela G. , Habib Namrah , Broadbeck Juliette I. , Bray Veronica J. , Bailey Samuel H.
Published: July 2021

Abstract. In this study, we report the results of an active-source seismology and
ground-penetrating radar survey performed in northwestern Greenland at a
site where the presence of a subglacial lake beneath the accumulation area
has previously been proposed. Both seismic and radar results show a flat
reflector approximately 830–845 m below the surface, with a seismic
reflection coefficient of −0.43 ± 0.17, which is consistent with the
acoustic impedance contrast between a layer of water and glacial ice.
Additionally, in the seismic data we observe an intermittent lake bottom
reflection arriving between 14–20 ms after the lake top reflection,
corresponding to a lake depth of approximately 10–15 m. A strong coda
following the lake top and lake bottom reflections is consistent with a
package of lake bottom sediments although its thickness and material
properties are uncertain. Finally, we use these results to conduct a
first-order assessment of the lake origins using a one-dimensional thermal
model and hydropotential modeling based on published surface and bed
topography. Using these analyses, we narrow the lake origin hypotheses to
either anomalously high geothermal flux or hypersalinity due to local
ancient evaporite. Because the origins are still unclear, this site provides
an intriguing opportunity for the first in situ sampling of a subglacial lake in
Greenland, which could better constrain mechanisms of subglacial lake
formation, evolution, and relative importance to glacial hydrology.
Avalanche danger level characteristics from field observations of snow instability
Authors: Schweizer Jürg , Mitterer Christoph , Reuter Benjamin , Techel Frank
Published: July 2021

Abstract. Avalanche danger levels are described in qualitative terms that mostly are not amenable to measurements or observations. However, estimating and improving forecast consistency and accuracy require descriptors that can be observed or measured. Therefore, we aim to characterize the avalanche danger levels based on expert field observations of snow instability. We analyzed 589 field observations by experienced researchers and forecasters recorded mostly in the region of Davos (Switzerland) during 18 winter seasons (2001–2002 to 2018–2019). The data include a snow profile with a stability test (rutschblock, RB) and observations on snow surface quality, drifting snow, signs of instability and avalanche activity. In addition, observers provided their estimate of the local avalanche danger level. A snow stability class (very poor, poor, fair, good, very good) was assigned to each profile based on RB score, RB release type and snowpack characteristics. First, we describe some of the key snowpack characteristics of the data set. In most cases, the failure layer included persistent grain types even after a recent snowfall. We then related snow instability data to the local avalanche danger level. For the danger levels 1–Low to 4–High, we derived typical stability distributions. The proportions of profiles rated poor and very poor clearly increased with increasing danger level. For our data set, the proportions were 5 %, 13 %, 49 % and 63 % for the danger levels 1–Low to 4–High, respectively. Furthermore, we related the local avalanche danger level to the occurrence of signs of instability such as whumpfs, shooting cracks and recent avalanches. The absence of signs of instability was most closely related to 1–Low and the presence of them to 3–Considerable. Adding the snow stability class and the 3 d sum of new snow depth improved the discrimination between the lower three danger levels. Still, 2–Moderate was not well described. Nevertheless, we propose some typical situations that approximately characterize each of the danger levels. Obviously, there is no single easily observable set of parameters that would allow us to fully characterize the avalanche danger levels. One reason for this shortcoming is the fact that the snow instability data we analyzed usually lack information on spatial frequency, which is needed to reliably assess the danger level.
Child and Family Benefits to Halt Hungary’s Population Decline, 1965-2020: A Comparison with Polish and Romanian Family Policies
Authors: Szántó Ildikó
Published: July 2021

Based on the long-term, demographic forecast, Hungary faces a significant population loss. This paper examines the continuing low level of Hungarian fertility, as well as the marked decline of population due to out-migration beginning in the mid-2000s. First, I will discuss the role governmental family policies play in halting fertility decline before 1989, the demographic post-transitional period of 1960-1980 and the past thirty years since 1989. Second, this paper particularly aims to highlight the impact of the new family policy since 2010, a reverse redistribution of resources from poor to the better-off families which did not result in a marked growth of birth rates. The new family benefits possibly further contribute to the existing polarization of Hungarian society without altering Hungary’s demographic data. Finally, the paper also compares the recent changes of family policies in Poland, Hungary and Romania since 2004.
Georg B. Michels. 2021. The Habsburg Empire under Siege: Ottoman Expansion and Hungarian Revolt in the Age of Grand Vizir Ahmed Köprülü. Montreal: McGill-Queen’s University Press, 2021. 603 pages.
Authors: Maxwell Alexander
Published: July 2021

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Koncepcija Latvijas kultūras mantojuma institūciju atsauču datu modelim
Authors:   LNB Bibliogrāfijas institūts, Skvireckis Eduards
Published: July 2021

Koncepcijā, balstoties uz datu standartiem un formātiem, kas atbilst visu Latvijas atmiņas institūciju datu semantiskās sadarbības iespējām konkrētajā situācijā un semantiskā tīmekļa principiem, ir izstrādāts jauns datu modelis ontoloģijai, piedāvātas vārdnīcas un dažādi klasifikatori, kā arī datu kartējums sadarbībai nosaukto entīšu vienveidīgai un kontrolētai lietošanai vienotajā kultūras mantojuma digitālo objektu izplatīšanas un pārvaldības platformā. Koncepcijas un konceptuālā modeļa mērķis ir aprakstīt esošo lietu un zināšanu reprezentācijas sistēmu, kas nebūtu piesaistīta konkrētām institūcijām un informācijas sistēmām. Šī platforma būtu jāsasaista ar citām pasaules kultūras mantojuma sistēmām, līdzdarbojoties vienota zināšanu tīklojuma veidošanā un bagātināšanā.
THE CONCEPTS OF AMANAT AND KIYANAT AS OPPOSITION
Authors: Dungenbay E. N. , Otarbekova Zh. K. , Kaymaz Z.
Published: July 2021

The article emphasizes the importance of conceptual study of terms that have linguistic meaning. In particular, one of the concepts reflecting the worldview of the Kazakh people was the concept of "amanat". For the cognitive disclosure of the concept of amanat, it is necessary to give a binary oppositional pair formed by the concept of "kiyanat" (abuse, violence), through which it is possible to determine the meaning of the concept of amanat for the people. To determine the application of the concept of amanat in the XIX-XX centuries, work was carried out with sources of that period, for example, the concept of amanat, found in the works of the traveler F. A. Fielstrup, the historian E. Bekmakhanov, describing that time, reflects the worldview of the people, as well as the analysis of proverbs and sayings that are firmly entrenched in the minds of the people, is widely reflected in this article. Kiyanat is widely discussed as a concept denoting violence, injustice, imperiousness and arbitrariness committed by a person when it is believed that the moral qualities of the offended person are destroyed. The concept of kiyanat forms a binary oppositional pair to the concept of amanat, hence we have grouped the types of abuse against a person, violence against oneself - an insult to the senses, lies, rude speech as an insult to the language. To determine how deeply modern society understands the concepts of amanat and kiyanat, a sociological survey was conducted, the results of which are presented in this work.
An Investigation of the Motivational Profile of EAP Learners at a Transnational Education English Medium Instruction University
Authors: Pack Austin
Published: July 2021

The number of transnational education (TNE) higher education institutions (HEI) around the globe is on the rise. This study attempts to examine the motivational profiles of English for Academic Purposes (EAP) learners at a TNE university in Mainland China that uses English as the medium of instruction (EMI). Participants (N = 300) were primarily first- and second-year students enrolled in EAP classes. The study relied on an adapted version of a motivational questionnaire (Taguchi et al., 2009) to measure some of the most commonly researched motivation constructs. Findings suggest that these students had relatively strong Ideal L2 Selves, were confident in their linguistic abilities, viewed learning EAP as being beneficial for their lives, and desired to integrate with or become like members of their respective academic or professional communities. No meaningful significant differences were found between the motivational profiles of male and female students. This Work-in-Progress study serves as an initial step towards understanding the motivational profiles of EAP learners within the TNE EMI context.
Diagnosis and treatment characteristics of mucinous ovarian tumors
Authors:   Nicolae Testemitanu State University of Medicine and Pharmacy, Republic of Moldova, Rotaru Tudor , Ludmila Rotaru ,   Nicolae Testemitanu State University of Medicine and Pharmacy, Republic of Moldova, Mocan Daniela ,   Nicolae Testemitanu State University of Medicine and Pharmacy, Republic of Moldova, Balan Nicu ,   Nicolae Testemitanu State University of Medicine and Pharmacy, Republic of Moldova
Published: July 2021

Ovarian tumors occupy a special place in gynecological pathology due to their great diversity, diagnostic difficulties, specifying their evolutionary nature, establishing the prognosis and treatment. Ovarian mucinous tumors are a group of rare formations, with a cell of as yet undefined origin, but with an apparent progression from benign to borderline and carcinoma. The treatment of a benign ovarian tumor is surgical. Material and methods. The research in question was performed on a group of 50 patients, who were treated in the gynecology department of the IMSP Oncological Institute of the Republic of Moldova, with the diagnosis of mucinous ovarian tumors. Results. The study analyzed data on the diagnosis and treatment of mucinous ovarian tumors. The clinical diagnosis showed a unilateral ovarian involvement in 41 cases (82%) compared to the bilateral one registered in 9 patients (18%). All tumors were large and irregularly shaped. In the case of laboratory diagnosis in assessing the benign or malignant tumor potential, the tumor marker CA-125 was performed, in 41 patients the index was within the norm range from 0-35U / ml and only in 9 cases were there insignificant increases of 50-100U / ml. Ultrasonographic diagnosis is an important method in detecting mucinous ovarian tumors. The treatment of patients is surgical and, depending on the appearance of the tumor intraoperatively and age, they had a radical or less radical character. Conclusions. The most common clinical signs were fullness in the pelvis, dysuria, pain in the lumbar or sacral region. As usual, the mucous ovarian tumors are large. The CA-125 tumor marker was in most cases within the normal range. Imaging investigations are informative and some of them applied to all patients in the study. Endoscopic diagnostic methods are less informative in mucinous ovarian tumors due to bulky formations and the risk of effusion of the mucin into the abdominal cavity.
The argumentation of the use of CBCT examination in endodontic treatment
Authors:   Nicolae Testemitanu State University of Medicine and Pharmacy, Republic of Moldova, Moraru Victor , Zagnat Vasile ,   Nicolae Testemitanu State University of Medicine and Pharmacy, Republic of Moldova
Published: July 2021

Purpose: to provide an overview in optimizing endodontic treatment using CBCT imaging. Objectives: 1. To evaluate the role of CBCT in the assessment of patients with periododontic disease. 2. Comparison of 2D imaging protocols (OPG, retroalveolar radiological film) image quality, information and commonly used radiation dose. Studying the literature and after analyzing our own clinical cases we argued the value of CBCT in endodontic treatment.
THE APPLICATIONS OF GIS FOR DEVELOPMENT SOME CHOOSING AREAS
Authors: Baylon M. Angelica , Panaitescu Mariana , Panaitescu F.
Published: July 2021

This paper introduces Geographic Information System and its applications using datasets and innovative for research, extension services and development. Case study with GIS datasets is available for the Catanduanes Island. This application is good and efficient and will be recommended for actions in building GIS capability of human resources and for an environmentally sustainable and socio-economically Catanduanes support. GIS technology serves for the holistic development of different areas, in our case, for Catanduanes Island.
Media Papan Pintar Pancasila sebagai Upaya Peningkatan Hasil Belajar Siswa Kelas II SD Negeri 2 Payaman Nganjuk
Authors: Pramitasari Indah
Published: July 2021

Salah satu pendidikan yang berperan sebagai pembentuk karakter bangsa yaitu Pendidikan Kewarganegaraan. Materi PPKn umumnya disajikan sangat teoritis, abstrak dan sulit dipahami oleh siswa. Selain itu, kurangnya keterampilan guru mengembangkan model dan media pembelajaran PPKn menyebabkan siswa kurang terlibat dalam proses pembelajaran, sehingga berdampak pada hasil belajar yang cukup rendah. Alternatif media pembelajaran yang dapat digunakan pada muatan PPKn ialah Papan Pintar Pancasila, dimana siswa dapat bermain dan mencocokkan gambar sesuai sila secara individu maupun kelompok. Tujuan dalam penelitian ini untuk meningkatkan hasil belajar PPKn melalui media Papan Pintar Pancasila pada siswa kelas II di SDN 2 Payaman, Nganjuk. Rancangan penelitian yang digunakan adalah penelitian tindakan kelas yang terdiri dari 2 siklus. Subjek penelitian ini adalah siswa kelas II SDN 2 Payaman Nganjuk yang berjumlah 27 siswa. Data penelitian diperoleh melalui observasi, tes, dan catatan lapangan. Data observasi kegiatan pembelajaran dianalisis dalam bentuk persentase dan nilai rata-rata kegiatan pembelajaran. Data tes hasil belajar siswa dianalisis dengan menjumlahkan nilai setiap aspek yang dinilai dan berdasarkan persentase ketuntasan belajar klasikal. Data catatan lapangan yang berisi berbagai kendala dianalisis kemudian dicari solusinya. Hasil penelitian menunjukkan bahwa hasil belajar siswa dalam pembelajaran mengalami peningkatan. Pada siklus I hasil belajar siswa mencapai 72,88% dan pada siklus II hasil belajar siswa mencapai 80,68%. Kesimpulan yang dapat diambil dari penelitian ini adalah penggunaan Media Papan Pancasila dapat meningkatkan hasil belajar siswa pada pembelajaran PPKn di kelas II SDN 2 Payaman Nganjuk.
Identification of C-H Bond Vibration Mode Using Absorption Spectroscopy By A Simple Optically Configured Setup
Authors: Ali Norshamsuri , Syed Junid Syed Alwee Aljunid , Ahmad Nor Azura Malini , Che Beson Mohd Rashidi , Endut Rosdisham
Published: July 2021

An optical system model for the identification of Carbon-Hydrogen stretching using spectroscopy is demonstrated and applied to the experiment setup. The optical simulation is achieved using simulation software and performed in a two-mirror system. The optical setup covers a wavelength range of 600 nm to 1200 nm which is a new study based on carbon-hydrogen stretch and test with samples from the alkene group. Significant results of the Carbon-Hydrogen stretch from the alkene group at 1149 nm are detected in Dichloromethane and ethanol. This observation is recorded in real-time and applied in a fast diagnostic system. The isosbestic point of water is measured at 970 nm and useful for our system spectral calibration. The result also shows the ability to quantify the chemical bond of a sample based on two peaks of absorption due to the C-H stretching. This gives a better opportunity for Chemometrics to perform accurately.
Adesão de sobreviventes de câncer de mama às recomendações nutricionais preventivas da recidiva da doença
Authors: Palacio Bruna Queiroz Allen , Sampaio Helena Alves de Carvalho , Henriques Eliane Mara Viana , Carioca Antonio Augusto Ferreira , Vergara Clarice Maria Araújo Chagas
Published: July 2021

Este artigo teve como objetivo analisar a adesão às recomendações nutricionais preventivas de recidiva do câncer de mama de mulheres em tratamento oncológico. A pesquisa foi desenvolvida em Fortaleza, Ceará, Brasil, com uma amostra de 201 mulheres. Realizou-se antropometria e entrevista para obtenção de dados demográficos, socioeconômicos, culturais e dietéticos. Estes últimos foram obtidos através do Questionário de Frequência Alimentar Elsa Brasil. Os dados foram comparados às recomendações preventivas e a adesão foi avaliada mediante um sistema de pontuação. A idade média foi de 50 anos e as melhores aderências às recomendações foram à ingestão de frutas e hortaliças (73,13%) e limitar o consumo de bebidas alcoólicas (88,56%) e de carne vermelha/processada (60,70%). As aderências mais baixas foram a manutenção de estado nutricional normal, considerando índice de massa corporal (27,36%) e circunferência da cintura (20,40%), consumo de fibras (30,35%) e limitar o consumo de bebidas açucaradas (12,94%). Maior adesão às recomendações esteve associada a um maior consumo de algumas vitaminas e minerais e um menor consumo de gorduras totais, saturadas e sódio. Foi possível observar que a adesão a todas as diretrizes é um desafio para os sobreviventes do câncer, demandando ações educativas a fim de prevenir recidiva da doença.
Caracterización clínico-epidemiológica de la enfermedad por coronavirus 2019 en edad pediátrica en San Pedro Sula, Honduras
Authors: Mejia Paz Norma Lidia , Banegas Mejía Néstor Raúl , Paredes Castillo Nathalia
Published: July 2021

Antecedentes: El 31 de diciembre de 2019, China comunicó un reporte de casos de neumonía de etiología desconocida. El 11 de febrero de 2020, la Organización Mundial de la Salud (OMS) denominó a la enfermedad por coronavirus 2019: COVID-19. En América Latina el primer caso se confirmó el 25 de febrero de 2020 en Brasil.  En Honduras se confirmaron los dos primeros casos de COVID-19 el 10 de marzo, y el primer caso en edad pediátrica en San Pedro Sula (S.P.S.) se confirmó el 25 de marzo de 2020. Objetivo: Caracterizar clínica y epidemiológicamente la enfermedad por coronavirus 2019 en la edad pediátrica en S.P.S., Honduras. Pacientes y métodos: Estudio cuantitativo, descriptivo, y transversal. Se utilizó un muestreo no probabilístico de 415 pacientes en edad pediátrica (IC 95%) a quienes se les realizó una prueba de reacción en cadena de la polimerasa en tiempo real (PCR-tr). Las variables estudiadas fueron: sociodemográficas, curso de la enfermedad, manifestaciones clínicas, factores de riesgo, manejo del paciente, condición actual del paciente y distribución según el establecimiento de salud notificante. La información recolectada fue ingresada en una base de datos y analizada en Microsoft Excel. Resultados: 170 (40.96%) pacientes en edad pediátrica resultaron positivos. El grupo etáreomás afectado fueron los adolescentes (54.71%). El curso de la enfermedad fue sintomático en 124 pacientes. El síntoma que más frecuentemente se reportó fue fiebre (37.10%). A la fecha de finalización del estudio, 152 continuaban activos con COVID-19. Conclusiones: Este estudio resume las principales características clínicas y epidemiológicas de la COVID-19 en niños y adolescentes de S.P.S.
Manifestaciones neurológicas de COVID-19. Revisión de la literatura
Authors: Garcia Carranza Carlos Genaro , Aguilar Pineda Cindy Monsserrath
Published: July 2021

El nuevo coronavirus se origino en la ciudad de Wuhan, China, esta enfermedad afecta principalmente el sistema respiratorio, los síntomas pueden ir desde leves a severos, así también, existe otra variedad de presentaciones clínicas en otros sistemas, como es el sistema nervioso central, actualmente existe evidencia de gran cantidad de publicaciones de presentación neurológica como manifestaciones de COVID-19. Actualmente se ha descrito el potencial neurotrópico del coronavirus para invadir el sistema nervioso central y también se ha descrito  diversos mecanismos de daño secundario. Las diferentes presentaciones neurológicas en niños como en adultos pueden ser variables, y estas incluyen manifestaciones del sistema nervios central, periférico y enfermedades musculares.
Construir estrategias colaboractivas y transductoras: entrevista a Tomás R. Villasante
Authors: Montañés Serrano Manuel , Zelaya Perdomo Iving
Published: July 2021

Tomás R. Villasante es profesor honorífico de la Universidad Complutense de Madrid. Tiene una amplia experiencia en instituciones de educación superior y procesos de transformación social en diversos países de Europa y América Latina. Es autor de numerosas publicaciones sobre metodología, práctica y teoría participativas. Forma parte de la Fundación CREASVI, Red CIMAS, y Red Sentipensante del Grupo CLACSO Procesos y metodologías participativas. Esta conversación se centra en sus reflexiones respecto a la pandemia de la COVID-19 y a las estrategias para la construcción de una normalidad alternativa.
Triple versus monoterapia antibiótica en apendicitis complicada: ensayo clínico abierto, Instituto Hondureño de Seguridad Social, Tegucigalpa.
Authors: Santos Karen , Lizardo José , Luque Marco T
Published: July 2021

Antecedentes: En Honduras no se dispone de evidencia publicada sobre diferencias en eicacia de esquemas terapéuticos basados en antibióticos para el manejo post-quirúrgico para apendicitis aguda complicada en niños. Objetivo: Determinar la eicacia y seguridad de triple versus monoterapia antibiótica en pacientes pediátricos con apendicitis aguda complicada, Hospital de Especialidades, Instituto Hondureño de Seguridad Social (IHSS), Tegucigalpa, 2011-2013. Métodos: Ensayo clínico abierto, dos esquemas terapéuticos: Triple Terapia (Ampicilina+Amikacina+Clindamicina, GrupoTT) y Ertapenem (GrupoE) durante 7 días. Se incluyeron pacientes con diagnóstico de apendicitis aguda complicada y sometidos a apendicectomía abierta. Los pacientes fueron evaluados en Consulta Externa, 7 días post-quirúrgicos. Se obtuvo aprobación por Comité de Etica en Investigación IHSS. Se utilizó prueba Chi-cuadrado, Riesgo Relativo, intervalo de conianza de 95% y valor de p<0.05 para determinar diferencias entre grupos. Resultados: Se incluyeron 58 pacientes en GrupoTT y 29 en Grupo E, edad media fue 7.3 años (IC95% 6.7-7.9) GrupoTT y 8 años (IC95% 7-9) GrupoE. La evolución promedio del cuadro clínico fue 31.6 horas GrupoTT y 43.8 horas GrupoE (p=0.034). No se encontró diferencias signiicativas respecto a efectos adversos de importancia clínica, complicaciones postoperatorias, estancia intrahospitalaria en días, o necesidad de readmisión por recurrencia/complicación posterior al alta. Discusión: La monoterapia con ertapenem presentó similar eicacia y seguridad que la triple terapia con Ampicilina+Amikacina+Clindamicina empleada actualmente en el tratamiento del paciente pediátrico con apendicitis complicada. El estudio está limitado por que los dos grupos de estudio fueron diferentes en la evolución de la enfermedad.
Diagnóstico de Hipertermia maligna: reporte de caso
Authors: Erazo Fino Luz Enid , Chávez Villanueva Lastenia Antonia , Torres Gonzáles Lesly Mayela
Published: July 2021

Antecedentes: La Hipertermia maligna, desorden farmacogenético autosómico dominante, se presenta en pacientes susceptibles a gases anestésicos; estimándose predisposición genética en 1:3000 individuos generada por las variantes de los genes RYR1, CACNA1, STAC3, que explican la susceptibilidad del 77%-86% de la población caucásica europea. Se reporta incidencia entre 1:5000-100000 procedimientos de anestesia. Se induce por liberación excesiva sin recaptación adecuada de calcio citoplásmico desde el retículo sarcoplásmico, generando rigidez muscular, alto gasto de energía como ATP, hipermetabolismo, aumento secundario de CO2, calor, rabdomiólisis, hiperpotasemia, mioglobinuria y aumento de CPK. Descripción del caso clínico: Paciente masculino 18 años sometido a cirugía con anestesia general por apendicitis aguda, durante la cirugía presentó rigidez muscular, inestabilidad hemodinámica, hipertermia (40°C), taquicardia (Frecuencia cardiaca: 120 lpm) e hipotensión (Presión Arterial 50/20), sin esfuerzo respiratorio y pérdida de relejos osteotendinosos. Se diagnosticó hipertermia maligna y se inició manejo, sin embargo, paciente fallece poco menos de dos horas después de haber iniciado el cuadro. Conclusiones: La Hipertermia maligna, es una condición que genera un evento en respuesta a la exposición a agentes anestésicos durante una cirugía, cuadro difícil de prevenir. El manejo requiere celeridad y preparación exhaustiva que debe seguir las recomendaciones de manejo europeas y estadounidenses. Este es el primer caso reportado a nivel nacional y se acompaña con una revisión que permite determinar que, aunque no se disponga del fármaco clave en el sistema nacional para mejorar el pronóstico, la protocolización preventiva y terapéutica, así como el entrenamiento en simulación del personal de quirófano podrían inluir en la supervivencia
Alta prevalencia en el consumo de tabaco y desigualdades en población Lenca, Intibucá, Honduras, 2015.
Authors: Arias Nancy Ninoska , Mendoza Carlos , Escalante Héctor , Bustillo José Tomas , Mayen Ana Lucía
Published: July 2021

Antecedentes: Aproximadamente un sexto de la población mundial tiene el hábito de fumar para una prevalencia de 24%. La OMS considera que, de no cambiar las tendencias durante el siglo XXI, el tabaco será responsable de la muerte prematura de mil millones de personas. Objetivo: Determinar la prevalencia del consumo de tabaco y la medición de desigualdades socioeconómicas en la población Lenca, Municipio de Intibucá, Intibucá, Honduras, 2015. Métodos: Estudio descriptivo transversal con análisis de asociación. Se aplicó formulario estructurado para recolectar datos generales, sociodemográficos y tabaquismo, previo consentimiento informado. Dependencia al tabaco fue evaluada con test Faguerström. Se prepararon bases de datos en Epi-info-7 y SPSS-18. Se calcularon razones de disparidad (OR). Resultados: De un total de 602 entrevistados, se identificaron 167 fumadores para una prevalencia de consumo de tabaco de 27.7%. El 76.6% (128) de fumadores tuvo dependencia baja a nicotina y 23.4% (39) dependencia moderada. La media de ingreso familiar mensual fue USD$193 en fumadores y USD$168 en no fumadores. El 40.1% (67) de fumadores gastó mensualmente en tabaco un mínimo de USD$95. No se encontró relación entre consumo de tabaco e ingreso familiar mensual (OR=0.87, IC95% 0.7-1.0) ni con analfabetismo (OR=1.20, IC95% 0.7-2.0). Discusión: No se observaron diferencias significativas entre consumo de tabaco y las variables socioeconómicas, se encontró una elevada prevalencia de consumo de tabaco en esta población en relación con otros estudios realizados en el país. Los resultados apoyan la necesidad de políticas enfocadas en prevención del tabaco en indígenas.
Miocarditis como manifestación inicial de Lupus Eritematoso Sistémico: Reporte de caso
Authors: Maldonado Triminio José Orlando , Rodríguez Aguilar Denis Gabriel , Izaguirre Rodríguez Eddlin Onán
Published: July 2021

Antecedentes: El Lupus Eritematoso Sistémico es una enfermedad autoinmune, sistémica, que involucra diferentes órganos incluyendo el corazón. Una de las manifestaciones cardíacas más comunes es la pericarditis; sin embargo, también se pueden presentar otras formas de afectación cardiaca entre las que se incluye la enfermedad arterial coronaria, arteritis y enfermedad valvular. Una de las presentaciones raras del lupus eritematoso sistémico incluye la miocarditis y una vez sospechada, debe ser diagnosticada y tratada con prontitud para evitar consecuencias fatales para el paciente. Descripción del caso: Presentamos un caso de una paciente femenina de 31 años con historia de dolor torácico, fiebre, fatiga, alteraciones ecocardiográficas y niveles elevados de troponina, a quien se le diagnóstico miocarditis y confirmación de Lupus Eritematoso Sistémico. El manejo fue terapia anti-isquémica e inmunoreguladores, con respuesta terapéutica y evolución satisfactoria. Conclusión: La miocardiopatía clínicamente evidente rara vez es la manifestación inicial de Lupus Eritematoso Sistémico, aunque también puede presentarse en el curso de la enfermedad con disfunción ventricular izquierda, insuficiencia cardiaca aguda y edema pulmonar, es de progresión rápida y requiere de diagnóstico y atención temprana, manejo multidisciplinario para evitar complicaciones fatales.
Análisis bibliométrico de la Revista Médica Hondureña, 1990-2020
Authors: Maradiaga Edna , Cecilia García Martha
Published: July 2021

Antecedentes: El análisis bibliométrico permite explorar retrospectivamente aspectos cuantitativos de la producción y citación, como valoración métrica de las publicaciones cientíicas. Objetivo: Caracterizar los artículos cientíicos publicados en la Revista Médica Hondureña (RMH), 1990-2020. Métodos: Estudio bibliométrico. La compilación de datos se realizó de las versiones impresa y electrónica de la RMH. Se analizaron las variables: año de publicación, volúmenes de la revista, números por volumen, tipo de artículos, número de citación, temas incorporados, ailiaciones institucionales, nacionales y extranjeras. El análisis incluyó los 110 números de los 31 volúmenes del periodo, del Volumen 58 Número 1 Año 1990 al Volumen 88 Número 2 Año 2020. Resultados: Se publicaron 1151 artículos, 26.2% (302) cientíicos originales, 19.4% (223) casos clínicos. El 13.9% (73/302) de los artículos cientíicos originales correspondió al área de salud pública. El 39.9% (459/1151) de los artículos publicados han sido citados, 38.3% (176) artículos originales, 20.7% (95) casos clínicos. El total de citas recibidas fue de 2087, equivalente a una media 67.3 citas por año y a 1.8 citas por artículo publicado. El año 2011 fue más citado por autores nacionales y latinoamericanos con 189 citas. Discusión: La producción cientíica de la RMH es diversa de acuerdo a su alcance, pero escasa en cantidad y visibilidad. Es necesario incorporar más indicadores bibliométricos para su indexación en bases de datos internacionales y plataformas, incluyendo las redes sociales, para aumentar su impacto y visibilidad.
Management of Copper Heap Leach Projects: A Geologist’s Perspective
Authors: Dreier John E.
Published: July 2021

Editor’s note: The Geology and Mining series, edited by Dan Wood and Jeffrey Hedenquist, is designed to introduce early-career professionals and students to a variety of topics in mineral exploration, development, and mining, in order to provide insight into the many ways in which geoscientists contribute to the mineral industry.

Copper production by heap leaching, coupled with solvent extraction and electrowinning (SX-EW), is a well-established technology, with an annual output of about 3.7 million tonnes (Mt) of copper metal. Ores presently amenable to copper heap leaching include copper oxides and secondary copper sulfides. Most copper deposits amenable to acid sulfate heap leaching result from supergene processes within porphyry copper systems, although copper heap leaching has been applied to sandstone and shale-hosted deposits, among others. Copper heap leaching is a rate-dependent process sensitive to copper mineralogy (copper oxides > secondary sulfides > hypogene sulfides), driven by the pH of the leach solution, the activity of ferric iron (Fe3+ (aq)) dissolved in the leach solution, and temperature. Acid consumption, a principal operating cost item, depends on the pH of the leach solution; the presence of reactive gangue minerals, notably carbonates, Ca plagioclase, pyroxene, Fe-rich amphibole, and olivine; and the cumulative surface area of material in the heap.

There are three basic approaches to commercial copper heap leaching—run-of-mine, dedicated pad, and on-off pad leaching, with variables that include crushing, acid/ferric agglomeration, solution application rate, and leach solution pH. These approaches affect copper leach kinetics, overall copper recovery, acid consumption, and capital and operating costs. A successful copper heap leach evaluation program requires a systematic approach, beginning with geologic mapping, then drilling and hydraulic and metallurgical testing, and concluding with financial analysis, engineering, and permitting. As geologists are the unique party in the process, with a thorough understanding of the overall deposit geology, including ore and gangue mineralogy, the domains that comprise the deposit, and the geochemistry of leaching, they must remain fully involved in the project throughout the evaluation. At the outset, geologists must manage the drilling program and define the grade-mineral domains. Later, they must participate in the metallurgical and hydraulic testing programs, including the evaluation of test results; then, during financial modeling, they must collaborate with all of the other specialists.
Woodcutters 55 Years Later: A New Look at an Old Discovery
Authors: Shatwell Dave
Published: July 2021

The Woodcutters Zn-Pb-Ag deposit in the Rum Jungle district of the Pine Creek orogen in northern Australia was discovered in 1964 and produced 4.6 Mt of ore grading 12.3% Zn, 5.6% Pb, and 83 g/t Ag between 1985 and 1999. Woodcutters, together with several other polymetallic, uranium, and phosphate deposits, is within a Paleoproterozoic sequence of fluviatile and shallow marine sediments deposited in a deepening basin between ~2100 and 2025 Ma around the margins of an Archean granitic and gneissic dome. These sediments were overlain by turbidites and volcaniclastic rocks until the basin was inverted and the sediments and mineral deposits were deformed and metamorphosed at 1860 Ma.

Whereas the polymetallic and uranium bodies at Rum Jungle are considered to be syngenetic or syndiagenetic, sulfides in the Woodcutters orebody replace dolomitic horizons in an otherwise carbonaceous unit. This suggests that Woodcutters is similar to Mississippi Valley-type mineralization and rules out affinities with younger sedimentary exhalative-style deposits elsewhere in the Pine Creek orogen. A model is proposed whereby metals were eroded from Archean basement rocks into Paleoproterozoic sandstone aquifers following the Great Oxidation Event, which also liberated sulfur by oxidation of pyrite. Evaporative conditions, as suggested by the widespread occurrence of dolomite and magnesite, may have increased the chloride content of seawater and enhanced its capacity to transport metals. Subsequently, deeply circulating seawater leached metals from the aquifers and ascended up a deep, basin-penetrating fault until it intersected carbonaceous sediments. In this environment, Zn and Pb sulfides were deposited under reducing conditions, while sulfur may have been provided by H2S from organic material.

The Woodcutters and other deposits at Rum Jungle show how metals formerly locked up in Archean cratons were delivered by erosion under an oxygenated atmosphere to Paleoproterozoic shorelines, where they were further mobilized and concentrated by a variety of processes.
Epithermal Precious Metal Deposits in South Korea—History and Pursuit
Authors: Wittwer Paul D.
Published: July 2021

The gold and silver endowment of Korea has historically been well known, with records alluding to production as far back as 1122 BC. The main gold production period was from 1925 to 1943 during the Japanese occupation of Korea, with more than 1 Moz recorded in 1939. Muguk was the most productive gold mining operation, located within the central region of South Korea, with a recorded 590 koz of gold produced from 1934 to 1998 (first mined in AD 912). The majority of the historical mining operations were closed by government order in 1943 during the Second World War and never reopened. A number of small mines operated between 1971 and 1998, with limited production during a period of gold prices generally lower than at present (~25–50% of current inflation adjusted prices, apart from a four-year period 1979–83). It is likely that significant resources remain within these historical mining areas. Gold-silver deposit types historically recognized and exploited in Korea include placers and orogenic and intrusion-related vein systems. Only more recently have epithermal vein and breccia systems been recognized. This is not surprising, given that the geologic and tectonic setting of the Southern Korean peninsula is prospective for epithermal precious metal deposits, spatially associated with basin-scale brittle fault systems in Cretaceous volcanic terranes. South Korea is an underexplored jurisdiction, with limited modern exploration and drilling until the mid-1990s, when Ivanhoe Mines Ltd. discovered the Gasado, Eunsan, and Moisan epithermal gold-silver deposits, all of which became mines. Exploration was limited for another 20 years until Southern Gold Ltd., an Australian Securities Exchange (ASX)-listed company, commenced regional-scale exploration for epithermal deposits, using a strategy similar to that successfully employed by Ivanhoe.
Assessment for Septic Arthritis in Immunocompetent and Immunocompromised Patients: A Single-Institution Study
Authors: Brown Chelsea R. , Samade Richard , Turnquist Emily , Mickley John , Lynch Daniel , Larkin Karilyn T. M. , Speeckaert Amy L.
Published: July 2021

Introduction:

Prompt diagnosis of septic arthritis is imperative to prevent irreversible joint damage. Immunocompromised patients are at an increased risk of septic arthritis as well as secondary systemic infection. Our aims were to identify features predictive of septic arthritis and to determine whether these features differed between immunocompetent and immunocompromised patients.

Methods:

A single institution retrospective cohort study was performed of 173 immunocompetent and 70 immunocompromised patients who underwent aspiration or arthrotomy for suspected septic arthritis from 2010 to 2018. Demographic data, symptoms, laboratory values, and imaging findings were recorded. Multiple variable logistic regression models were used to assess for predictive factors for septic arthritis in both cohorts. Results were reported as odds ratios, 95% confidence intervals, and P values.

Results:

In the regression analysis, independent predictive factors for septic arthritis in immunocompetent patients were younger age (P = 0.004), presence of radiographic abnormalities (P = 0.006), and C-reactive protein (CRP) (P < 0.001). For immunocompromised patients, only CRP was an independent continuous predictive factor (P = 0.008) for septic arthritis. A risk stratification tool for predicting septic arthritis in immunocompetent patients using age <55 years, CRP >100 mg/dL, and presence of radiographic abnormalities was developed. A similar tool was created using CRP >180 mg/dL and radiographic abnormalities in immunocompromised patients.

Discussion:

Differences in predictive factors for septic arthritis between immunocompromised and immunocompetent patients suggest dissimilar clinical presentations. The developed risk stratification tools allow one to predict the likelihood of septic arthritis in both groups. This may permit more accurate selection of patients for surgical intervention in the setting of insufficient data from synovial aspiration.
Thumb Carpometacarpal Instability
Authors: Rabinovich Remy V. , Polatsch Daniel B. , Shin Steven S. , Beldner Steven
Published: July 2021

The basal joint complex of the thumb provides the framework necessary for function of the human hand. Although its unique saddle articulation allows for a wide range of motion necessary for routine function of the hand, it is rendered inherently unstable because of poor bony congruency and reliance on its capsuloligamentous support. Painful instability of this joint can stem from several causes including traumatic dislocation, various hypermobility conditions, and chronic overuse and microtrauma. A thorough history and examination as well adequate imaging is necessary for proper evaluation of instability. Treatment options range from nonoperative modalities to surgery, which entails closed, percutaneous, or open reduction with numerous ligament repair and reconstruction techniques. Arthroscopy can also serve to be a useful adjunct for assessment of the joint and stabilization of the critical capsuloligamentous structures. This review outlines the critical osseous and soft-tissue anatomy surrounding the thumb carpometacarpal joint, the key points in evaluating patients presenting with acute traumatic and chronic thumb carpometacarpal instability without fracture or arthritis, and reviews both nonoperative and operative treatments of this injury.
Problema APSP via Dimensão-VC e Médias de Rademacher
Authors: Lima Alane M. de , Vignatti André L. , Silva Murilo V. G. da
Published: July 2021

Considere o problema de computar o caminho mínimo entre cada par de vértices (APSP) de um grafo, desde que o caminho tenha alta centralidade, sendo que a métrica de centralidade em questão reflete a "importância'' do caminho no grafo. Propomos um algoritmo para este problema que usa uma estratégia de amostragem baseada em Dimensão-VC e médias de Rademacher. No caso de grafos esparsos de diâmetro logarítmico, que comumente modelam situações reais, o tamanho da amostra é exponencialmente menor do que aquelas obtidas por técnicas clássicas (e.g.: Hoeffding e limitante da união).
Computational Paths and the Fundamental Groupoid of a Type
Authors: Ramos Arthur F. , Queiroz Ruy J. G. B. de , Oliveira Anjolina G. de
Published: July 2021

Using computational paths as the fundamental concept, we show that we can leverage Category Theory to propose the concept of fundamental groupoid of a type.
Árvores Ramsey-restritas mínimas
Authors: Collares Maurício , Fernandes Antônio K. B. , Mota Guilherme O. , Vicente Hugo M.
Published: July 2021

Para grafos G, S e H, dizemos que G mr-flecha (S,H) se toda coloração das arestas de G tem uma cópia monocromática de S ou uma cópia multicolorida de H. Provamos que se S = K_{1,3} e H é uma árvore binária completa de altura h, então o tamanho da menor árvore T que mr-flecha(S,H) é 2^{(1/2+o(1))h^2}.