Spin-phonon coupling effects in transition-metal perovskites:a DFT+UU and hybrid-functional study

Spin-phonon coupling effects, as reflected in phonon frequency shifts between ferromagnetic (FM) and G-type antiferromagnetic (AFM) configurations in cubic CaMnO$_3$, SrMnO$_3$, BaMnO$_3$, LaCrO$_3$, LaFeO$_3$ and La$_2$(CrFe)O$_6$, are investigated using density-functional methods. The calculations are carried out both with a hybrid-functional (HSE) approach and with a DFT+$U$ approach using a $U$ that has been fitted to HSE calculations. The phonon frequency shifts obtained in going from the FM to the AFM spin configuration agree well with those computed directly from the more accurate HSE approach, but are obtained with much less computational effort. We find that in the $A$MnO$_3$ materials class with $A$=Ca, Sr, and Ba, this frequency shift decreases as the A cation radius increases for the $\Gamma$ phonons, while it increases for R-point phonons. In La$M$O$_3$ with $M$=Cr, Fe, and Cr/Fe, the phonon frequencies at $\Gamma$ decrease as the spin order changes from AFM to FM for LaCrO$_3$ and LaFeO$_3$, but they increase for the double perovskite La$_2$(CrFe)O$_6$. We discuss these results and the prospects for bulk and superlattice forms of these materials to be useful as multiferroics.Comment: 13 pages, 7 figures, 9 table

Ancient DNA genomics and the renaissance of herbaria

Herbaria are undergoing a renaissance as valuable sources of genomic data for exploring plant evolution, ecology, and diversity. Ancient DNA retrieved from herbarium specimens can provide unprecedented glimpses into past plant communities, their interactions with biotic and abiotic factors, and the genetic changes that have occurred over time. Here, we highlight recent advances in the field of herbarium genomics and discuss the challenges and opportunities of combining data from modern and time-stamped historical specimens. We also describe how integrating herbarium genomics data with other data types can yield substantial insights into the evolutionary and ecological processes that shape plant communities. Herbarium genomic analysis is a tool for understanding plant life and informing conservation efforts in the face of dire environmental challenges

Duality Defects in E8E_8

We classify all non-invertible Kramers-Wannier duality defects in the $E_8$ lattice Vertex Operator Algebra (i.e. the chiral $(E_8)_1$ WZW model) coming from $\mathbb{Z}_m$ symmetries. We illustrate how these defects are systematically obtainable as $\mathbb{Z}_2$ twists of invariant sub-VOAs, compute defect partition functions for small $m$, and verify our results against other techniques. Throughout, we focus on taking a physical perspective and highlight the important moving pieces involved in the calculations. Kac's theorem for finite automorphisms of Lie algebras and contemporary results on holomorphic VOAs play a role. We also provide a perspective from the point of view of (2+1)d Topological Field Theory and provide a rigorous proof that all corresponding Tambara-Yamagami actions on holomorphic VOAs can be obtained in this manner. We include a list of directions for future studies.Comment: 51+15 pages, 7 figures, 8 table

Mining ancient microbiomes using selective enrichment of damaged DNA molecules

The identification of bona fide microbial taxa in microbiomes derived from ancient and historical samples is complicated by the unavoidable mixture between DNA from ante- and post-mortem microbial colonizers. One possibility to distinguish between these sources of microbial DNA is querying for the presence of age-associated degradation patterns typical of ancient DNA (aDNA). The presence of uracils, resulting from cytosine deamination, has been detected ubiquitously in aDNA retrieved from diverse sources, and used as an authentication criterion. Here, we employ a library preparation method that separates molecules that carry uracils from those that do not for a set of samples that includes Neandertal remains, herbarium specimens and archaeological plant remains

Soil and Site Improvements of the Marsh Soils in Puerto De Santa María Highway (Cádiz, Spain)

The Puerto de Santa Maria and Puerto Real news highways are 17.4 kms. long, of which about 9 kms. run through a marshland area. The soft soil surveys involved piezocone reconnaissances and the construction of 3 experimental embankments. The embankments rest on ground improved with vertical drains for heights between 2.5 and 4.0 m., and with gravel columns for heights between 4.0 and 9.0 m. Expanded polystyrene was also used, for the first time in Spain, as a light fill in the embankments providing access to one of the bridges. The foundations for the 9 bridges located in the marshland were large diameter, precast, driven pier-piles (Raymond type). Embankment settlement was monitored and controlled by continuous settlement measuring lines. Pile driving was also PDA controlled

Inferencia en modelo de regresión lineal múltiple con errores de distribución secante hiperbólica generalizada

We study multiple linear regression model under non-normally distributed random error by considering the family of generalized secant hyperbolic distributions. We derive the estimators of model parameters by usingmodified maximum likelihood methodology and explore the properties of the modified maximum likelihood estimators so obtained. We show that the proposed estimators are more efficient and robust than the commonly used least square estimators. We also develop the relevant test of hypothesis procedures and compared the performance of such tests vis-a-vis the classical tests that are based upon the least square approach. Estudiamos el modelo de regresión lineal múltiple bajo errores aleatorios no distribuidos normalmente considerando la familia de distribuciones hiperbólicas secantes generalizadas. Derivamos los estimadores de los parámetros del modelo utilizando la metodología modificada de máxima verosimilitud y exploramos las propiedades de los estimadores modificados de máxima verosimilitud así obtenidos. Mostramos que los estimadores propuestos son más eficientes y robustos que los estimadores de mínimos cuadrados comúnmente utilizados. También desarrollamos la prueba relevante de los procedimientos de hipótesis y comparamos el rendimiento de tales pruebas con las pruebas clásicas que se basan en el enfoque de mínimos cuadrados.&nbsp

Non-Syndromic Multi Focal Non-Ossifying Fibroma: A Diagnostic Challenge of Giant-Cell Rich Lesions

Background: Diagnosing GCL can be extremely difficult due to the rarity of these lesions. Histologically many benign GCL mimic each other and can further be mistaken for a malignant GCL. Additionally confusing the diagnosis, many benign GCL have significant morphological overlap. However, it is of utmost importance to arrive at an accurate diagnosis as treatment varies significantly based on the pathology. Our patient presentation highlights that differentiating GCLs can be a diagnostic challenge as illustrated. Our review of the literature found scarce reports of multifocal non-ossifying fibroma. In this case report, we describe a non-syndromic multifocal non-ossifying fibroma successfully treated with biopsy curettage and grafting. This patient was informed that her case would be submitted for publication and she agreed. Case: A 14 year-old-girl complained of left knee pain for 3 months and radiographic imaging showed a destructive bone lesion at her distal femoral metaphysis, the tibial tubercle, and proximal fibula. The patient had no history of trauma and reported no infectious, inflammatory, or syndromic symptoms. Core biopsy of the left thigh lesion showed findings most consistent with giant cell tumor. Bone scintigraphy revealed new lesions at the distal femur and proximal tibia on the contralateral (right) side. Patient was treated with biopsy curettage and grafting. Intra-operative frozen section permanent reads showed giant-cell rich non-ossifying fibroma. Due to discrepancy in core biopsy and intra-operative biopsy a independent pathology consult was requested on surgical specimens. Histologically, the differential diagnosis included non-ossifying fibroma, giant cell tumor of bone, and ossifying fibroma. Radiographic imaging combined with histology gave a final pathological diagnosis most consistent with non-ossifying fibroma. Conclusion: Differentiating non-syndromic multifocal non-ossifying fibroma from other giant cell rich lesions can be a diagnostic challenge. A combined approach using histology, clinical presentation, and radiology is imperative in reaching the correct diagnosis

Validación de la escala CRUSADE para evaluar el riesgo de sangrado en pacientes con infarto agudo de miocardio sin elevación del ST

ResumenObjetivoEvaluar si la escala CRUSADE es aplicable en la comunidad colombiana.MétodosSe realizó un estudio de validación externa dentro de una cohorte histórica, en el que se incluyeron pacientes hospitalizados entre los años 2006 y 2012 en el Hospital Universitario San Ignacio, en Bogotá, Colombia. Se tomaron historias clínicas de pacientes mayores de 18 años, que tuvieran asignado el diagnóstico de infarto agudo de miocardio sin supradesnivel del ST. Se comparó el número de eventos (sangrado) predichos y observados durante la hospitalización (calibración). Finalmente, se estimó la capacidad para separar sujetos de alto y bajo riesgo (discriminación).ResultadosSe incluyeron 252 pacientes. El número de eventos mayores fue 30 (11,9%) y el de eventos menores 23 (9,12%); 12 pacientes (7,46%) fallecieron. En el grupo de muy alto riesgo (más de 50 puntos de la escala), se reportó el mayor número de eventos (respecto a la población estudiada). Al evaluar la escala se evidenció una buena capacidad de calibración (X2 p=0,84); sin embargo, la discriminación no fue adecuada (área bajo la curva 0,6128 [IC 95% 0,46-0,76]).ConclusionesSe encontraron pocos eventos, si bien los datos sugieren que la escala subestima levemente los riesgos. La escala tiene buena calibración, pero no posee capacidad de discriminación adecuada, hecho que probablemente obedece a que se obtuvo un pequeño número de eventos, con desviaciones estándar altas. Por tanto, se requieren estudios adicionales, con mayor poder estadístico.AbstractObjectiveTo assess whether CRUSADE scale is applicable in the Colombian community.MethodsA study of external validation in a historical cohort, which included patients hospitalized between 2006 and 2012 in the Hospital Universitario San Ignacio in Bogota Colombia, was performed. Medical records of patients older than 18 years, who had been diagnosed as acute myocardial infarction without ST segment elevation, were included. The number of events (bleeding) predicted and observed during hospitalization (calibration) were compared. Finally, the ability to separate subjects at high and low risk (discrimination) was estimated.Results252 patients were included. The number of major events was 30 (11.9%) and that of minor events 23 (9.12%); 12 patients (7.46%) died. In the group of very high risk (more than 50 points on the scale), the largest number of events (regarding the study population) was reported. At assessing the scale, a good calibration capacity was evidenced (X2 p=.84); however, discrimination was not adequate (0.6128 AUC [95% CI 0.46 to 0.76]).ConclusionsFew events were found, although the data suggest that the scale slightly underestimates the risks. The scale has good calibration, but lacks adequate discriminatory capacity, probably due to the fact that a small number of events with high standard deviations were obtained. Therefore, further studies with greater statistical power are required