bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efecto mutagénico de los herbicidas paraquat y glifosato en <i>Salmonella typhimurium</i>
Authors: Salazar G. James , Zuleta B. Margarita 
Published: January 2023

En el presente trabajo se evaluó la mutagenicidad de los herbicidas paraquat (1,1'.dimetil-4,4-bipiridinium cloruro) y glifosato [N-(fosfonometil) glicina] usando el test de Ames con Salmonella typhimurium, cepas TA97, TA98, TA100, TA102, en presencia o ausencia de S-9, con y sin preincubación.Las dosis de paraquat utilizadas fueron 0.2, 2.0 y 20.0 ug/caja y únicamente la segunda dosis produjo efecto mutagénico positivo en la cepa TA100, bajo todas las condiciones experimentales empleadas. Es posible que el mecanismo de acción mutagénica del paraquat sea similar al de los mutágenos oxidativos, ya que este herbicida genera radicales de oxígeno cuya implicación en la acción mutagénica y a ha sido demostrada. Las dosis de glifosato utilizadas fueron 0.48, 4.80 y 48.00 ug/caja. Las tres dosis resultaron positivas en las cuatro cepas, bajo todas las condiciones experimentales empleadas.Según los resultados de este trabajo, el glifosato en su formulación comercial puede ser considereado mutágeno directo y fuerte. Parece que el glifosato en su formulación comercial tiene mayor potencialidad mutagénica que en su estado puro, aunque con los datos obtenidos en el presente trabajo no se puede concluir si dicho efecto es ocasionado por los compuestos presentes en la mezcla, o si es originado por una interacción entre el principio activo del herbicida y los componentes presentes en la formulación comercial. Es importante, por lo tanto, identificar los compuestos presentes en la formulación comercial del herbicida y evaluar el efecto mutagénico de cada uno de ellos.
Pesquisa de <i>Sarcocystis</i> sp. en lengua de cerdo mediante cortes histológicos examinados en microscopios de luz y electrónico
Authors: García Martha Rocío , Marinkelle Cornelis Johannes 
Published: January 2023

Se examinaron mediante microscopios de luz y electrónico 100 cortes histológicos de lengua de cerdos de diferentes regiones de Colombia que llegaban al Frigorífico de Guadalupe en Santafé de Bogotá. El 9% de los cerdos contenían quistes intramusculares de Sarcocystis sp. Con el microscopio de luz se encontraron 136 quistes. El número de quistes por muestra estaba entre 2 y 44, y en un caso se encontraron 28. Los quistes midieron, en cortes transversales, 24.3 102.4 x 17.9 91.2 ????m, y en cortes longitudinales 56.3 962 x 24.3 591.5 ????m. La dimensión de los zoitos fue 3.2 4.5 x 1.28 2.8 ????m.Con el microscopio electrónico se observaron pocos metrocitos en el interior de los quistes, principalmente ubicados en la periferia, y se caracterizaron por su citoplasma voluminoso y gránulos de amilopectina. Los zoitos presentaban organelos característicos como micronemas, rotrias, núcleo, aparto de Golgi, gránulos de amilopectina y gránulos densos. Se observaron de dos a tres roptrias por zoito. Aunque se determinó el diámetro de la pared de los quistes observados en cortes histológicos no fue posible identificar la especie de Sarcocystis.
Características biológicas del blanquillo Sorubim cuspicaudus littmann; Burr y Nass, 2000 y Bagre rayado Pseudoplatystoma magnaleniatumBuitrago-Suárez y Burr, 2007 (Siluriformes: Pimelodidae).
Authors: Jiménez-Segura Luz Fernanda F. , Palacio Jaime , López Raúl 
Published: January 2023

Algunas características biológicas de Pseudoplatystoma magdaleniatum y de Sorubim cuspicaudus fueron monitoreadas durante los años 2004 y 2005 en la cuenca media del río Magdalena y, analizamos si estas se encuentran sincronizadas con la densidad de larvas de estas dos especies derivando en el río Magdalena. Para esto se utilizó la información de 1.245 individuos adultos de P. magdaleniatum y 1.206 de S. cuspicaudus y la densidad de sus larvas en muestras de agua del río Magdalena. S. cuspicaudus se reproduce durante el periodo de “aguas bajas” mientras que P. magdaleniatum lo hace durante el periodo de “aguas subiendo”. Las hembras de las dos especies fueron siempre de mayor tamaño que los machos, la relación longitud-peso fue alométrica y solo en el caso de P. magdaleniatum las características biológicas estuvieron sincronizadas con la densidad de larvas durante el periodo de observación.
Hallazgo de oofagia canibalística en <i>Peltocephalus dumerilianus</i> (Testudines: Podocnemididae)
Authors: De La Ossa-V. Jaime , Vogt Richard C. , De La Ossa-Lacayo Alejandro 
Published: January 2023

Se presenta por primera vez el hallazgo de oofagia canibalística en Peltocephalus dumerilianus (Schweigger, 1812) (Testudines: Podocnemididae), detectada durante un estudio de dieta en medio natural para esta especie, en el cual se examinaron muestras de contenidos estomacales e intestinales provenientes de 36 animales adultos, capturados como caza de subsistencia por las comunidad ribereña de São Luís, municipio de Barcelos, Amazonas, Brasil. En el contenido del tracto intestinal de una hembra se localizaron membranas externas correspondientes a ocho huevos de su misma especie; se reafrma el carácter oportunista y generalista que P. dumerilianus (cabezudo) posee en su comportamiento de alimentación natural.
Interseismic Strain Accumulation between the Colorado Plateau and the Eastern California Shear Zone: Implications for the Seismic Hazard near Las Vegas, Nevada
Authors: Young Zachary M. , Kreemer Corné , Hammond William C. , Blewitt Geoffrey 
Published: January 2023

ABSTRACTCrustal deformation in the central Basin and Range between the Colorado plateau and the Eastern California Shear Zone is active but slow, making it a challenge to assess how strain is distributed and crustal motion transferred. However, knowledge of strain rates is very important, particularly for addressing the seismic hazard for both the Las Vegas urban area and the site of the proposed Yucca Mountain nuclear waste repository, in southern Nevada. Global Positioning System (GPS) data provide important constraints, particularly now that the GPS network in the area has substantially expanded in recent years. However, because deformation is slow, it is important to mitigate any transient tectonic and nontectonic signals to obtain the most accurate long-term interseismic motion and robust estimation of strain rates. We use data from all GPS stations in the region including both long-running continuous and semicontinuous stations. We model and remove postseismic displacements at these stations using source parameters for 41 events, dating back to the 1700 Cascadia megathrust earthquake, which contribute significantly to the deformation field within the central Basin and Range. We also remove correlated noise from the time series with the common-mode component imaging technique. We find that removal of both the postseismic transients and common-mode noise substantially reduces the uncertainties and spatial variation in the velocities. We find east–west extension across the Las Vegas Valley of 0.5–0.6 mm/yr. The interseismic strain rate field, calculated with the final velocities, reveals higher strain rates through southern Nevada than in previous studies, with rates within Las Vegas Valley of 8.5±2.4×10−9  yr−1. Our results also confirm shear along the Pahranagat shear zone, but the estimated amplitude is strongly affected by postseismic relaxation.
Does maximum earthquake size depend on focal depth?
Authors: Frohlich Cliff 
Published: January 2023

AbstractWhile the Gutenberg-Richter “law” (GR) with b-value of 1.0 is an inexact description of the earthquake frequency-magnitude distribution, it does provide a convenient statistical basis for identifying when the largest earthquakes in a catalog are either anomalously large or anomalously small. When the largest earthquakes are as predicted by the GR distribution, it is inappropriate to infer that the largest historically known earthquake is the largest possible. Only when the largest observed earthquakes are significantly smaller than predicted can we infer that the largest possible earthquakes have occurred. Analysis of the global historical catalog demonstrates that at nearly all depths, the largest deep and intermediate earthquakes have sizes close to those predicted by a GR distribution with b of 1.0. Only between about 300 to 450 km and beneath 600 km are the largest known earthquakes somewhat larger than predicted. However, when geographically isolatable subgroups within catalogs are considered separately, largest earthquakes that are either anomalously large or small are quite common. Often this is because individual regions have b-values much different than 1.0; alternatively, sometimes there appear to be physical constraints limiting the size of the largest possible earthquake. As examples illustrating these assertions, this article evaluates two subgroups—deep-focus earthquakes occurring beneath Spain and intermediate-depth earthquakes in the Bucaramanga, Colombia, “nest.”
The spectral element method: An efficient tool to simulate the seismic response of 2D and 3D geological structures
Authors: Komatitsch Dimitri , Vilotte Jean-Pierre 
Published: January 2023

AbstractWe present the spectral element method to simulate elastic-wave propagation in realistic geological structures involving complieated free-surface topography and material interfaces for two- and three-dimensional geometries. The spectral element method introduced here is a high-order variational method for the spatial approximation of elastic-wave equations. The mass matrix is diagonal by construction in this method, which drastically reduces the computational cost and allows an efficient parallel implementation. Absorbing boundary conditions are introduced in variational form to simulate unbounded physical domains. The time discretization is based on an energy-momentum conserving scheme that can be put into a classical explicit-implicit predictor/multi-corrector format. Long-term energy conservation and stability properties are illustrated as well as the efficiency of the absorbing conditions. The associated Courant condition behaves as ΔtC &lt; O (nel−1/ndN−2), with nel the number of elements, nd the spatial dimension, and N the polynomial order. In practice, a spatial sampling of approximately 5 points per wavelength is found to be very accurate when working with a polynomial degree of N = 8. The accuracy of the method is shown by comparing the spectral element solution to analytical solutions of the classical two-dimensional (2D) problems of Lamb and Garvin. The flexibility of the method is then illustrated by studying more realistic 2D models involving realistic geometries and complex free-boundary conditions. Very accurate modeling of Rayleigh-wave propagation, surface diffraction, and Rayleigh-to-body-wave mode conversion associated with the free-surface curvature are obtained at low computational cost. The method is shown to provide an efficient tool to study the diffraction of elastic waves by three-dimensional (3D) surface topographies and the associated local effects on strong ground motion. Complex amplification patterns, both in space and time, are shown to occur even for a gentle hill topography. Extension to a heterogeneous hill structure is considered. The efficient implementation on parallel distributed memory architectures will allow to perform real-time visualization and interactive physical investigations of 3D amplification phenomena for seismic risk assessment.
Identification of presumed shallow underwater chemical explosions using land-based regional arrays
Authors: Baumgardt Douglas R. , Der Zoltan 
Published: January 2023

Abstract
Seismic events located in the Gulf of Bothnia, the Baltic Sea, and the North Sea, recorded at the regional seismic arrays NORESS and FINESA, have characteristics of underwater blasts observed hydroacoustically. Spectral analysis of regional phases associated with the events reveals strong time-independent spectral scalloping indicating that the waveforms are made up of correlated “pulse-echo” type signals. Cepstral analysis gives consistent delay times between the pulse-echo pairs with the most common delays between 400 and 600 msec. Some cepstra also have negative peaks at quefrencies between 150 and 350 msec. The cepstral peaks are observed in all phases associated with the event, and events recorded at both arrays have the same delay times. The higher time delays are consistent with bubble-pulse delays commonly observed in underwater blasts recorded hydroacoustically. The lower-quefrency negative peaks are caused by echoes with reversed polarities relative to the primary pulse and are consistent with reflections from the top of the water column. Generally, these events have large Pn/Lg amplitude ratios similar to those observed from quarry blasts. Somewhat smaller high-frequency Pn/Lg ratios are observed for Baltic Sea events compared with the North Sea events, which may be due to differences in the water-bottom geologies of the two regions. Simple source models of underwater blasts explain many of the features of the observed cepstra and indicate that the shot depths had to be shallow (around 40 to 80 m) for shot sizes between 75 and 150 kg. This study shows that the seismic sensor network, called for by the Comprehensive Test Ban Treaty (CTBT), can augment the smaller network of hydroacoustic stations for the detection and identification of clandestine under-water nuclear-explosion tests in the near offshore environment.
Finite-element numerical simulation of tsunamis generated by earthquakes near a circular island
Authors: Piatanesi Alessio , Tinti Stefano 
Published: January 2023

Abstract
A numerical model for the propagation of tsunamis generated by earthquakes is applied to study the impact of the water waves against the coast of a circular island. The hydraulic source is modeled by means of the static deformation of the seafloor produced by an offshore seismic fault. The initial sea-surface disturbance is assumed to equal the seabed displacement that is computed analytically through the classical dislocation theory of plane faults with uniform slip. The wave propagation is described by means of the shallow-water approximation of the Navier-Stokes equations and is computed in a radially symmetric domain for which a quasi-analytical solution is available. The governing equations are solved numerically by means of a finite-element (FE) method making use of the Galerkin procedure, the mesh consisting of triangular elements of variable size. After a preliminary test of the numerical model against the analytical results, several simulations are performed by varying the fault location, dimension, and dip as well as by varying the radial profiles of the basin bathymetry. Most attention is devoted to studying the amplification of tsunami waves impacting the island coast. What is seen is that, depending on the source characteristics (namely, fault length, dip, strike, and distance from the island) and on the basin bathymetry, high amplifications (in the range 1 to 5) are normally obtained not only in the front of the island as is expected but also on the lee side of the island, because of positive interference of waves traveling around the island in both directions. Under particular conditions (downwardly concave bathymetry), the largest amplifications are found neither on the front side nor on the lee side, but at intermediate places along the island coast.
Bacteremia in Cancer Patients as a Prognostic Factor and the Relationship with Chemotherapy
Authors: Macedo Filipa , Monteiro Joana , Julio Neidy , Bonito Nuno 
Published: January 2023

Introduction: Bacteremia is a cause of morbi-mortality in cancer patients, due to its severity, longer hospital stays, chemotherapy withdraw, and increased costs. The study aimed to clarify if bacteriemia in cancer patients is associated with higher mortality rates and alert the community to this emerging problem. Methods: The authors collected every cancer patient hospitalized in our cancer center, who developed bacteremia during their stay in hospital or at admission, in the last 9 years. Data was treated with SPSS. The p-values <0.05 were considered to be statistically significant. Results: From 204 bloodstream infections, almost half of the patients had gastrointestinal cancer (49%). Males were predominant (54,4%) and the median age was 66 years-old. The catheter-totally-implanted was responsible in 38,7% of the cases. From all bacteria, 20,5% were multidrug-resistant and 48% were resistant to at least one antibiotic. From all patients, 61,5% received chemotherapy the month before the infection. The survival of those that did received chemotherapy was significantly different from patients that did not, t(203)= 2,06, p=0,04. Chemotherapy the month before was correlated with lower survival rates, r(203)=-0,15, p=0,03, and Kaplan-Meyer curve showed a tendency towards statistically significance (p=0,06). The stage of the oncologic disease was not associated with the mortality of the patient (p>0,05). The infection contributed or was the cause of death in 45% of the patients. The 3 months mortality rate of the patients that had bacteriemia was 74,5%. Conclusion: Currently there are no guidelines regarding prescription of antimicrobial therapy in cancer patients. Three quarters of the cancer patients that suffer bacteriemia died in 3 months, and active chemotherapy treatment is associated with lower survival rates. Keywords: oncology; bloodstream infection; multidrug-resistant bacteria; antibiotic stewardship.
Pemodelan Regresi Logistik Berbasis Backward Elimination Untuk Mengetahui Faktor yang Mempengaruhi Tingkat Kemiskinan di Indonesia Tahun 2021
Authors: Alfi Indah Nurrizqi  , Erfiani  , Indahwati  , Anwar Fitrianto  , Reni Amelia  
Published: January 2023

Kemiskinan seringkali berhubungan dengan masalah kesejahteraan dan menjadi salah satu masalah utama di Indonesia. Kondisi ekonomi akibat Covid-19 berdampak pada tingkat kemiskinan di masyarakat. Penelitian ini bertujuan untuk mengetahui faktor-faktor yang memengaruhi tingkat kemiskinan di Indonesia tahun 2021 menggunakan regresi logistik biner. Regresi logistik biner digunakan untuk memodelkan hubungan antara variabel respon yang terdiri dari dua kategori dengan satu atau lebih variabel prediktor. Hasil penelitian ini menunjukkan proporsi tingkat kemiskinan rendah lebih tinggi dibandingkan tingkat kemiskinan tinggi. Terdapat 18 provinsi dengan tingkat kemiskinan rendah serta 16 provinsi dengan tingkat kemiskinan tinggi. Faktor-faktor yang berpengaruh terhadap kategori pada tingkat kemiskinan yaitu Indeks Pembangunan Manusia (X1) dan Gini Ratio (X2). Ketepatan klasifikasi dari model sebesar 83.33%, yang artinya model baik digunakan.
Analisis Non-Hierarchical Clustering dan Lagrangean Multiplier dalam Penentuan Bobot Portofolio Optimal Saham Perbankan Indonesia
Authors: Putri Isnaini Cahyaning Baiti  , Prasetya Jus 
Published: January 2023

Investment banking is a financial entity. Investment banking is an important financial intermediary that is indispensable in the capital market. The increasing interest of investors in investing in the stock market has increased because the stock market offers flexible and transparent money options opportunities for risk sharing with the potential for positive returns. Every investor wants a high rate of return with a low risk value. Risk cannot be eliminated, but can be minimized. Clustering means finding and defining a number of clusters (or groups) in a data set. Grouping is done based on numerical equations or distances (dissimilarities). The k-means algorithm is a grouping algorithm based on distance. In the k-means algorithm, the smaller the distance between the samples, the higher the similarity. The k-medoids algorithm is used to find medoids in a cluster which is the center point of the cluster. The return value or commonly known as the return on the funds invested in the investment. Portfolio is a collection of several investment instruments formed with the aim of meeting investment goals. obtained 5 clusters using k-means algorithm with total of wss 23,606. The optimal portfolio weight percentage for each stock formed is BMAS (9.11%%), BANK (32.78%), ARTO (28.84%), BBYB (16.72%), and BBHI (12.54%). Furthermore, from the results of the optimization calculations that have been obtained,the expected return portfolio value is and the portfolio variance is . Investing Rp.1.000.000.000,-, then the expected return value that will be obtained when choosing this portfolio is Rp.11.094.300,-.
The Strategy of Islamic Religious Education Teachers at Junior High Schools to Deal with Frustrated Students in Online Learning During the Covid_19 Pandemic
Authors: Nafiyanti Septina 
Published: January 2023

<p class="06IsiAbstrak"><em>Students at SMP Negeri 6 Jepara are used to receiving lessons directly from the teacher. They at school can interact directly with their friends. However, the Covid-19 Pandemic changed the learning that has been lived so far. Students take online learning. This learning had caused unpreparedness. Some students need help understanding the material being taught. Limited interactions. This condition caused frustration among some students. Handling and avoiding students from frustration requires the role of Islamic Religious Education teachers. This study describes the strategy of Islamic Religious Education teachers at SMP Negeri 6 Jepara as a decisive step for handling and avoiding student frustration with online learning. The approach used in this research is field research. The study found that Islamic Religious Education teachers at SMP Negeri 6 Jepara made lesson plans according to the conditions of the Covid-19 Pandemic, maintained student learning comfort, controlled student learning activity, provided student learning motivation, and increased students' spiritual intelligence.</em><strong></strong></p><p class="07KatakunciKeywords"> </p><strong>Strategi Guru PAI SMP Menghadapi Siswa Frustrasi Pembelajaran Dalam Jaringan Saat Pandemi Covid-19.</strong> Siswa di SMP Negeri 6 Jepara terbiasa menerima pembelajaran secara langsung dari guru. Mereka di sekolah dapat berinteraksi secara langsung dengan teman-temannya. Namun, Pandemi Covid-19 mengubah pembelajaran yang selama ini dijalani. Siswa mengikuti pembelajaran daring. Pembelajaran ini sempat menimbulkan ketidaksiapan. Sebagian siswa kesulitan memahami materi yang diajarkan. Interaksi yang dijalani terbatas. Kondisi itu sampai menimbulkan rasa frustrasi di kalangan sebagian siswa. Penanganan dan menghindarkan siswa dari frustrasi membutuhkan peran guru Pendidikan Agama Islam. Penelitian ini mendeskripsikan strategi guru Pendidikan Agama Islam SMP Negeri 6 Jepara sebagai langkah ampuh untuk penanganan dan menghindarkan siswa frustrasi dengan pembelajaran daring. Pendekatan yang digunakan dalam penelitian ini adalah penelitian lapangan. Hasil penelitian menemukan guru Pendidikan Agama Islam di SMP Negeri 6 Jepara membuat rencana pembelajaran sesuai kondisi Pandemi Covid-19, menjaga kenyamanan belajar siswa, mengontrol keaktifan belajar siswa, memberi motivasi belajar siswa, dan meningkatkan kecerdasan spiritual siswa.