El plancton de las lagunas de gravera y el fósforo : el enriquecimiento de las paradojas

Durante las últimas décadas se han formulado explícitamente varias hipótesis sobre el funcionamiento de las comunidades pelágicas lacustres en relación con el enriquecimiento en fósforo. Entre ellas, se cuentan: 1ª) la relación directa entre fósforo y biomasa planctónica, 2ª) los máximos de la riqueza específica planctónica a niveles intermedios de fósforo, 3ª) la desestabilización de los grupos funcionales de la red trófica debida al enriquecimiento en fósforo (ó "paradoja del enriquecimiento"), 4ª) el hecho de que la biomasa planctónica en todos los niveles sea el resultado de la interacción entre el recurso limitante (el fósforo, en este caso) y la red trófica encabezada por los peces ictiófagos, y 5ª) la marcada influencia del enriquecimiento y de los peces ictiófagos sobre el espectro de tamaños planctónicos. Con objeto de comprobar estas hipótesis, realizamos un estudio estacional durante año y medio sobre el plancton de 16 lagunas de gravera situadas en el valle del río Jarama (Madrid), las cuales presentan un gradiente claro de fósforo total promedio (36-2500 μg P/L) y pueden o no albergar peces ictiófagos, aunque casi todas tengan ciprínidos. La 1ª hipótesis sólo se cumplió para bacterias, fitoplancton y rotíferos, pero no para las restantes comunidades planctónicas. La 2ª hipótesis se refutó, pues los máximos de riqueza específica se presentaron en las lagunas hipertróficas. La 3ª hipótesis no se comprobó y, en el caso de bacterias y fitoplancton consumible por herbívoros, tuvo lugar una estabilización de los mismos con el aumento de fósforo; probablemente, el efecto estabilizador de la omnivoría debida a copépodos y a ciprínidos fuera el responsable de este resultado. Los peces ictiófagos afectaron favorablemente a la biomasa de cladóceros, no alcanzando su efecto a los niveles inferiores de la red, controlados claramente por el fósforo, lo cual prestó apoyo a la idea de la interacción entre fuerzas ascendentes y descendentes de la red trófica, pero refutó la idea de la cascada trófica. Tanto el fósforo como los peces ictiófagos influyeron sobre el espectro de tamaños de modo antagónico, lo cual complicó la 5ª hipótesis. La conclusión general de este ejercicio de contraste de hipótesis es -además de la obvia de continuar investigando las redes tróficas planctónicas- que necesitamos hipótesis más globales en apoyo epistemológico de este enriquecimiento de las paradojas que hemos observado.Several hypotheses have been outlined on the relationship of lake communities and phosphorus enrichment in recent years. Some of them are the following: i) a positive relationship between phosphorus and planktonic biomass, ii) species richness peaks at intermediate phosphorus concentrations, iii) the destabilisation of food web functional groups arising from phosphorus enrichment (called the paradox of enrichment), iv) the plankton biomass as the outcome of interactions between the limiting resource (phosphorus in most lakes) and the food web, and v) the remarkable influence of phosphorus enrichment and piscivorous fish on planktonic size spectra. To test these hypotheses, we carried out a seasonal study on plankton communities of sixteen gravel-pit lakes for fifteen months in the river Jarama plain (Madrid, Central Spain). These lakes showed a wide range of average phosphorus contents (36-2500 μg P/L), piscivorous fish lived in some of them and most harbour benthic, omnivorous ciprinids. Hypothesis i was only demonstrated for bacteria, phytoplankton and rotifers. Hypothesis ii was refuted since species richness peaks occurred in hypertrophic lakes. Hypothesis iii was not supported by our data, and we even found a stabilisation of bacterial and edible phytoplankton populations along with phosphorus enrichment, such a stabilisation being a likely result of omnivory by copepods and ciprinids. As expected, piscivorous fish influenced cladoceran and bacterial density whereas phosphorus enrichment increased phytoplankton biomass, but the top-down effect did not affect phytoplankton, rotifers and copepods, thus supporting the bottom-up:top-down model against the trophic cascade model. Both phosphorus and piscivorous fish impinged on planktonic size spectra, albeit in an antagonistic way, and hence hypothesis v must be made more comprehensive. In addition to the obvious necessity of further studies on planktonic food webs, this exercise of hypothesis testing suggests that more comprehensive hypotheses should be built to support epistemologically the enrichment of paradox observed

Bovine diseases causing neurological signs and death in Mexican feedlots

Abstract The number of large feedlot operations, similar to that of USA and Canada, has notably increased in Mexico in the last three decades. Clinical and laboratory diagnoses of neurological diseases in feedlot cattle are crucial in Mexico and Central America because of the high incidence of bovine paralytic rabies (BPR). Because of its zoonotic potential, BPR must be promptly diagnosed and differentiated from other bovine neurological diseases such as thrombotic meningoencephalitis (TME), polioencephalomalacia (PEM) and botulism. More recently, BPR and botulism have been diagnosed with increasing frequency in Mexican feedlots. Neither BPR nor botulism has relevant gross lesions, thus post-mortem diagnosis without laboratory support is impossible. Herein, we describe five outbreaks of neurological diseases in Mexican feedlots in which BPR, botulism and PEM were diagnosed either independently or in combination. A diagram illustrating the most conspicuous pathologic findings and ancillary laboratory test required to confirm the diagnoses of these neurological diseases in feedlot cattle is proposed

ELSI: A Unified Software Interface for Kohn-Sham Electronic Structure Solvers

Solving the electronic structure from a generalized or standard eigenproblem is often the bottleneck in large scale calculations based on Kohn-Sham density-functional theory. This problem must be addressed by essentially all current electronic structure codes, based on similar matrix expressions, and by high-performance computation. We here present a unified software interface, ELSI, to access different strategies that address the Kohn-Sham eigenvalue problem. Currently supported algorithms include the dense generalized eigensolver library ELPA, the orbital minimization method implemented in libOMM, and the pole expansion and selected inversion (PEXSI) approach with lower computational complexity for semilocal density functionals. The ELSI interface aims to simplify the implementation and optimal use of the different strategies, by offering (a) a unified software framework designed for the electronic structure solvers in Kohn-Sham density-functional theory; (b) reasonable default parameters for a chosen solver; (c) automatic conversion between input and internal working matrix formats, and in the future (d) recommendation of the optimal solver depending on the specific problem. Comparative benchmarks are shown for system sizes up to 11,520 atoms (172,800 basis functions) on distributed memory supercomputing architectures.Comment: 55 pages, 14 figures, 2 table

Ataxia enzoótica por deficiencia de cobre en ciervo rojo (Cervus elaphus) cautivo en Colima, México

The objective of the study was to describe a case of enzootic ataxia in a captive Cervus elaphus (red deer) associated with copper deficiency, in the state of Colima, Mexico. In July and October 2018, two female red deer aged 3 and 7 yr manifested incoordination with weakness of the hind limbs and an anatomopathological diagnosis of progressive ataxia was established. In September 2019, a 13-yr-old female showed nervous signs similar to the 2018 cases, so a blood sample was taken for serum copper measurement. The animal was euthanized for post-mortem examination and tissue samples were collected for histology, liver, kidney, forage and soil samples were also taken for copper and molybdenum measurement. The main lesions were found microscopically in spinal cord, which showed leukomalacia, demyelination, spheroid bodies and neuronal chromatolysis. The copper concentration was 2.7 in liver, 4.67 in kidney and 0.08 in serum (mg/kg DM or ppm). The Cu:Mo ratio for soil 1 was Cu 8.48; Mo 3.00; Cu:Mo 2.83:1, soil 2: Cu 9.10; Mo 3.00; Cu:Mo 3.03:1. Forage 1: Cu 6.59; Mo 7.35; Cu:Mo 0.90:1; forage 2: Cu 2.77; Mo 6.12 ± 0.61; Cu:Mo 0.45:1. Clinical signs, microscopic lesions, and low levels of Cu in serum, liver, and forage are consistent with enzootic ataxia due to primary copper deficiency. As far as known, this is the first report of enzootic ataxia in a captive red deer in Mexico.El objetivo del trabajo fue describir un caso de ataxia enzoótica en un Cervus elaphus (ciervo rojo) cautivo asociado a deficiencia de cobre, en el estado de Colima, México. En julio y octubre del 2018 dos hembras de ciervo rojo de 3 y 7 años manifestaron incoordinación con debilidad de los miembros posteriores y se estableció un diagnóstico anatomopatológico de ataxia progresiva. En septiembre del 2019 una hembra de 13 años manifestó signos nerviosos similares a los casos del 2018, por lo que se tomó una muestra de sangre para la medición sérica de cobre. Al animal se le aplicó eutanasia para su examen post mortem y se recolectaron muestras de tejido para histología, también se tomaron muestras de hígado, riñón, forraje y suelo para la medición de cobre y molibdeno. Las principales lesiones se encontraron microscópicamente en medula espinal, que mostró leucomalacia, desmielinización, cuerpos esferoides y cromatolisis neuronal. La concentración de cobre fue 2.7 en hígado, 4.67 en riñón y 0.08 en suero (mg/kg MS o ppm). La relación Cu:Mo para el suelo 1 fue Cu 8.48; Mo 3.00; Cu:Mo 2.83:1, suelo 2: Cu 9.10; Mo 3.00; Cu:Mo 3.03:1. Forraje 1: Cu 6.59; Mo 7.35; Cu:Mo 0.90:1; forraje 2: Cu 2.77; Mo 6.12 ± 0.61; Cu:Mo 0.45:1. Los signos clínicos, lesiones microscópicas y los niveles bajos de Cu en suero, hígado y forrajes son consistentes con ataxia enzoótica por deficiencia primaria de cobre. Hasta donde se conoce, este es el primer informe de ataxia enzoótica en un ciervo rojo cautivo en México

Ovine pulmonary adenocarcinoma in Mexico

El adenocarcinoma pulmonar ovino es una neoplasia pulmonar transmisible del ganado ovino causada por un beta retrovirus actualmente denominado retrovirus Jaagsiekte de las ovejas (JSRV). Las células Club (anteriormente llamadas células de Clara) de los bronquiolos y los neumocitos de tipo II de los alvéolos son las células oncogénicas que constituyen el objetivo de este virus. Se caracteriza clínicamente por tos intermitente, secreción nasal abundante y pérdida de peso progresiva, los tumores afectan aleatoriamente a todos los lóbulos pulmonares o tienen una distribución cráneo-ventral que simula una bronconeumonía. El diagnóstico definitivo del adenocarcinoma pulmonar ovino requiere que se identifique el retrovirus Jaagsiekte de las ovejas RVJO-Env, o bien, la presencia de proteínas específicas asociadas en las células neoplásicas, tales como la proteína oncogénica JSRV-Env. Un ovino Pelibuey macho de dos años con un historial de tos crónica y pérdida de peso progresiva fue tratado sin éxito con antibióticos y murió unos días más tarde. El examen post mortem reveló edema pulmonar y varias masas nodulares localmente extensas en los pulmones. A nivel microscópico, los tejidos tumorales estaban compuestos por grupos de células epiteliales neoplásicas que mostraban un patrón de crecimiento lepídico típico del carcinoma pulmonar. Las células tumorales fueron inmunopositivas para la proteína oncogénica Env del retrovirus Jaagsiekte de la oveja. Con base en estos hallazgos, se hizo el diagnóstico final de adenocarcinoma pulmonar ovino.Ovine pulmonary adenocarcinoma is a transmissible pulmonary malignancy of sheep caused by a beta-retrovirus currently named Jaagsiekte sheep retrovirus (JSRV). Club cells (formerly Clara cells) in the bronchiole and type II pneumonocytes in the alveoli are the target oncogenic cells for this virus. Characterized clinically by intermittent cough, abundant nasal discharge, and progressive weight loss, the tumors randomly involve all lung lobes or have a cranioventral distribution mimicking bronchopneumonia. The definitive diagnosis of ovine pulmonary adenocarcinoma requires identifying Jaagsiekte sheep retrovirus or associated specific proteins in neoplastic cells such as JSRV-Env oncogenic protein. A two-year-old Male Pelibuey sheep with a history of chronic cough and progressive weight loss was treated unsuccessfully with antibiotics and died a few days later. Postmortem examination revealed lung edema and several nodular to locally extensive masses in the lungs. Microscopically the tumoral tissues were composed of clusters of neoplastic epithelial cells exhibiting a lepidic growth pattern typical of pulmonary carcinoma. Tumoral cells were immunopositive for Jaagsiekte sheep retrovirus-Env oncogenic protein. Based on these findings, the final diagnosis of ovine pulmonary adenocarcinoma was made

ELSI -- An open infrastructure for electronic structure solvers

Routine applications of electronic structure theory to molecules and periodic systems need to compute the electron density from given Hamiltonian and, in case of non-orthogonal basis sets, overlap matrices. System sizes can range from few to thousands or, in some examples, millions of atoms. Different discretization schemes (basis sets) and different system geometries (finite non-periodic vs. infinite periodic boundary conditions) yield matrices with different structures. The ELectronic Structure Infrastructure (ELSI) project provides an open-source software interface to facilitate the implementation and optimal use of high-performance solver libraries covering cubic scaling eigensolvers, linear scaling density-matrix-based algorithms, and other reduced scaling methods in between. In this paper, we present recent improvements and developments inside ELSI, mainly covering (1) new solvers connected to the interface, (2) matrix layout and communication adapted for parallel calculations of periodic and/or spin-polarized systems, (3) routines for density matrix extrapolation in geometry optimization and molecular dynamics calculations, and (4) general utilities such as parallel matrix I/O and JSON output. The ELSI interface has been integrated into four electronic structure code projects (DFTB+, DGDFT, FHI-aims, SIESTA), allowing us to rigorously benchmark the performance of the solvers on an equal footing. Based on results of a systematic set of large-scale benchmarks performed with Kohn–Sham density-functional theory and density-functional tight-binding theory, we identify factors that strongly affect the efficiency of the solvers, and propose a decision layer that assists with the solver selection process. Finally, we describe a reverse communication interface encoding matrix-free iterative solver strategies that are amenable, e.g., for use with planewave basis sets. Program summary: Program title: ELSI Interface CPC Library link to program files: http://dx.doi.org/10.17632/473mbbznrs.1 Licensing provisions: BSD 3-clause Programming language: Fortran 2003, with interface to C/C++ External routines/libraries: BLACS, BLAS, BSEPACK (optional), EigenExa (optional), ELPA, FortJSON, LAPACK, libOMM, MPI, MAGMA (optional), MUMPS (optional), NTPoly, ParMETIS (optional), PETSc (optional), PEXSI, PT-SCOTCH (optional), ScaLAPACK, SLEPc (optional), SuperLU_DIST Nature of problem: Solving the electronic structure from given Hamiltonian and overlap matrices in electronic structure calculations. Solution method: ELSI provides a unified software interface to facilitate the use of various electronic structure solvers including cubic scaling dense eigensolvers, linear scaling density matrix methods, and other approaches

A Review of Accelerometry-Based Wearable Motion Detectors for Physical Activity Monitoring

Characteristics of physical activity are indicative of one’s mobility level, latent chronic diseases and aging process. Accelerometers have been widely accepted as useful and practical sensors for wearable devices to measure and assess physical activity. This paper reviews the development of wearable accelerometry-based motion detectors. The principle of accelerometry measurement, sensor properties and sensor placements are first introduced. Various research using accelerometry-based wearable motion detectors for physical activity monitoring and assessment, including posture and movement classification, estimation of energy expenditure, fall detection and balance control evaluation, are also reviewed. Finally this paper reviews and compares existing commercial products to provide a comprehensive outlook of current development status and possible emerging technologies

"Drop a bomb on them...and problem solved" An analysis of poverty discourse on TikTok

This research analyzes the discursive characteristics of hate messages posted on TikTok Spain against people at risk of social exclusion. Using critical discourse analysis, we analyzed 679 hateful messages generated by 100 videos found about poverty. This method considered the social groups mentioned in those messages, actions attributed to them, the evaluative concepts associated with those actions, and the solutions proposed to eradicate this social problem. We used the qualitative analysis software Atlas.ti to code, categorize, and analyze co-occurrences of derogatory terms. The analysis shows that poverty is linked to migration, laziness, and groups at risk of exclusion. Although insults and degrading terms take on a metaphorical form or are less prevalent, the call to violent action is explicit, openly advocating the extermination of these groups. Underlying these messages is a clear neo-Nazi ideology gaining ground with the advance of the extreme political Right.Ministerio de Economía y CompetitividadAgenia Estatal de Investigación (AEI)Depto. de Periodismo y Comunicación GlobalFac. de Ciencias de la InformaciónTRUEpu

Metazoan and protozoan pathology of wild opossums (Didelphis virginiana) in Mexico

ABSTRACT: The aim was to describe the incidence and lesions caused by metazoan and protozoan parasites in Didelphis virginiana opossums in Mexico. From 2019 to 2021, twenty D. virginiana were collected from the state of Colima, Mexico. Post mortem, parasitological, and histopathological studies were performed to identify and describe their lesions and findings. All opossums(20/20) presented at least one type of parasite of the twelve found; the most abundant were nematodes 58.33% (7/12) Didelphostrongylus hayesi, Turgida turgida, Cruzia sp., Viannaia sp., Trichuris didelphis, Trichostrongylidae and Gnathostoma sp. Protozoa 25% (3/12), including Sarcocystis sp., Besnoitia sp., and Sarcocystis sp. A single specimen of Mathevotaenia sp., 8.3% (1/12), and Paragonimus mexicanus 8.3%, were identified (1/12). The most affected systems were the digestive, respiratory, and musculoskeletal. The most abundant parasites were Turgida turgida (20/20) 100%, Cruzia sp., (16/20) 80%, and Viannaia sp. (6/20) 30%, followed by Sarcocystis sp. cysts, (6/20) 30%. The associated parasitic lesions were: D. hayesi produce eosinophilic granulomatous bronchopneumonia, P. mexicanus eosinophilic focal granulomatous pneumonia, and Besnoitia sp., focal eosinophilic lymphoplasmacytic interstitial pneumonia. Gnathostoma and T. turgida caused severe eosinophilic granulomatous focal gastritis. Viannaia sp., Sarcocystis sp., Mathevotaenia sp., and Trichostrongylidae; caused diffuse eosinophilic mucosal enteritis. Cruzia sp., and T. didelphis, induced diffuse eosinophilic mucosal typhlitis. Sarcocystis sp. cysts were detected in the cytoplasm of muscle fibers without histological changes