Clones with finitely many relative R-classes

For each clone C on a set A there is an associated equivalence relation analogous to Green's R-relation, which relates two operations on A iff each one is a substitution instance of the other using operations from C. We study the clones for which there are only finitely many relative R-classes.Comment: 41 pages; proofs improved, examples adde

Prognostic factors of a lower CD4/CD8 ratio in long term viral suppression HIV infected children

Background Combination antiretroviral therapy (cART) is associated with marked immune reconstitution. Although a long term viral suppression is achievable, not all children however, attain complete immunological recovery due to persistent immune activation. We use CD4/CD8 ratio like a marker of immune reconstitution. Methods Perinatal HIV-infected children who underwent a first-line cART, achieved viral suppression in the first year and maintained it for more than 5 years, with no viral rebound were included. Logistic models were applied to estimate the prognostic factors, clinical characteristics at cART start, of a lower CD4/CD8 ratio at the last visit. Results 146 HIV-infected children were included: 77% Caucasian, 45% male and 28% CDC C. Median age at cART initiation was 2.3 years (IQR: 0.5-6.2). 42 (30%) children received mono-dual therapy previously to cART. Time of undetectable viral load was 9.5 years (IQR: 7.8, 12.5). 33% of the children not achieved CD4/CD8 ratio >1. Univariate analysis showed an association between CD4/CD8 <1 with lower CD4 nadir and baseline CD4; older age at diagnosis and at cART initiation; and a previous exposure to mono-dual therapy. Multivariate analysis also revealed relationship between CD4/CD8 <1 and lower CD4 nadir (OR: 1.002, CI 95% 1.000-1.004) as well as previous exposure to mono-dual therapy (OR: 0.16, CI 95% 0.003-0.720). Conclusions CD4/CD8 > 1 was not achieved in 33% of the children. Lower CD4 nadir and previous exposure to suboptimal therapy, before initiating cART, are factors showing independently association with a worse immune recovery (CD4/CD8 < 1)

Intoxicação experimental por monofluoroacetato de sódio em bovinos: aspectos clínicos e patológicos

Monofluoracetato de sódio (MF) foi identificado, por cromatografia, em três das doze plantas que causam morte súbita em bovinos no Brasil, incluindo Palicourea marcgravii, a mais importante desse grupo. Uma lesão considerada típica por alguns autores para intoxicação foi¹ a degeneração hidrópico-vacuolar dos túbulos uriníferos contorcidos distais (DHV). O objetivo deste trabalho foi verificar se a ingestão de MF induz sinais clínicos e lesões similares às observadas nos bovinos intoxicados pelas plantas que causam morte súbita. Seis vacas receberam, por via oral, 0,5 e 1,0mg/kg de MF diluídos em 50mL de água destilada. Clinicamente, os animais apresentaram taquicardia, jugular repleta com pulso venoso positivo, respiração abdominal, ligeira perda de equilíbrio, por vezes cambaleavam, deitavam e apoiavam a cabeça no flanco. Na fase final (agônica), todos os animais caíam em decúbito lateral, esticavam os membros, faziam movimentos de pedalagem, apresentavam opistótono, nistagmo, mugidos e a morte ocorria em 2-14 minutos. À necropsia verificaram-se aurículas, jugulares, ázigos e pulmonares moderadamente ingurgitadas. Observaram-se ainda leve a moderado edema da subserosa nos locais de fixação da vesícula biliar no fígado, além de leve edema entre o duodeno e o pâncreas. O exame histopatológico revelou, em todos os animais, desde leve a acentuada DHV das células epiteliais dos túbulos uriníferos contorcidos distais associada à cariopicnose. Com relação à ultraestrutura, observou-se vacuolização do citoplasma devido ao acúmulo de água. Vacuolização e necrose de coagulação individual ou de grupos de hepatócitos e leve congestão hepática secundários à estase venosa também foram observados. DHV tem sido observada em casos de envenenamento por outras substâncias, porém nestes não está restrita aos túbulos distais e não se observa cariopicnose. Este estudo demonstra que a DHV dos túbulos renais de bovinos pode ser causada pelo envenenamento por MF e, por analogia, essa substância deve ser considerada como um dos fatores importantes, senão o mais significativo, implicado na morte dos animais que ingerem plantas que causam morte súbita no Brasil. Isso indica que estudos, que envolvam metabolização de MF por bactérias ruminais, teriam grande aplicabilidade econômica, uma vez que pelo menos 500.000 bovinos morrem anualmente intoxicados por plantas do grupo das que causam morte súbita no Brasil.Sodium monofluoroacetate (MF) was identified, by cromatography, in three of the 12 plants that cause sudden death in cattle in Brazil, including Palicourea marcgravii, the most important plant of this group. A special kind of hydropic-vacuolar degeneration (HVD) of the distal convoluted uriniferous tubules was considered typical for the poisoning by some authors. The objective of this study was to verify if the ingestion of MF causes similar clinical signs and lesion in cattle poisoned by plants that cause sudden death. Six cows received orally 0.5 and 1.0mg/kg of M diluted in 50mL of distilled water. Clinically the animals presented tachycardia, engorgement and positive pulse of the jugular vein, abdominal breathing, swaying gait, subtle unbalance, and recumbency with head placed the on the flank. In the agonal phase all the animals in lateral recumbence presented muscular fasciculation, tonic contraction, peddling movements, opisthotonus, nystagmus, and died between 2 and 14 minutes. At postmortem examination, the heart auricles, jugular and pulmonary veins were moderately distended and engorged with blood. Slight to moderate edema of the subserosa was seen around the gall bladder and the duodenum near to the pancreas. At light microscopy, HVD associated with nuclear picnosis of the epithelial cells of the distal convoluted uriniferous tubules was present in all animals. Ultrastructurally, the cell lesion represents formation of cytosolic vacuoles, likely due to accumulation of water. Coagulation necrosis of individual or groups of hepatocytes and slight hepatic congestion secondary to the venous stasis were also observed. Hydropic-vacuolar degeneration has been observed in cases of poisoning by many substances, which cause acute tubular nephrosis, however not restricted to the distal renal tubules and without nuclear picnosis. This study demonstrates that the HVD in the kidney can be caused by MF and, in analogy, the compound should be considered responsible for the death of cattle that ingest toxic plants which cause sudden death in Brazil. Our results can be supportive to studies that will focus on the degradation of MF by rumen bacteria, what might have economic implications, as at least 500.000 cattle die annually by sudden death causing toxic plants in Brazil

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Initial survival of the Isis® total trapeziometacarpal prosthesis with conical trunk threaded cups

Introducción El tratamiento de la rizartrosis del pulgar mediante la implantación de prótesis totales está en continua expansión. La prótesis Isis® es un implante de cúpula troncocónica de anclaje roscado y semiconstreñida. Nuestro objetivo fue valorar los resultados funcionales y de supervivencia de este implante durante un mínimo de un año de evolución. Material y método Estudio prospectivo sobre 53 prótesis Isis® implantadas entre abril de 2014 y enero de 2019. Se evaluaron el test funcional de Van Cappelle, dolor, fuerza, movilidad, regreso a la actividad, variables radiológicas y colocación de la cúpula. La técnica quirúrgica se realizó siempre con aguja guía centrada en el trapecio y control de escopia. Se registraron complicaciones y se llevó a cabo un análisis estadístico. Resultados Se revisaron 51 implantes (49 pacientes) con un seguimiento medio de 2,1 años (1-5,7). El test de Van Cappelle, el dolor, la movilidad y la fuerza de puño y pinza mejoraron significativamente; también la distancia entre cabeza de metacarpiano y base de trapecio. El 96% de los pacientes regresaron en menos de 6 meses a sus actividades. Las complicaciones registradas fueron: 3 tendinopatías de De Quervain, 2 fracturas de metacarpiano y 2 de trapecio intraoperatoriamente, y un síndrome del túnel carpiano. No hubo ninguna luxación, infección ni movilización del implante en el último seguimiento. Conclusiones Los resultados funcionales de la prótesis Isis® son excelentes a corto plazo, con una supervivencia del 100% tras el primer año de evolución. Las complicaciones surgidas fueron escasas. El anclaje y colocación de la cúpula guiada por escopia parecen ser cruciales para el buen resultado.Introduction The treatment of trapeziometacarpal osteoarthritis through the implantation of total trapeziometacarpal prostheses is in continuous expansion. The Isis® prosthesis is a trunk-conical threaded anchorage prosthesis. Our objective was to assess the functional results and survival of this implant for at least one year of follow-up. Material and method Prospective study on 53 Isis® prosthesis, implanted from april 2014 to january 2019. The Van Cappelle functional test, pain, strength, mobility, return to previous activity, radiological variables and placement of the trapezial component were evaluated. The surgical technique was performed with a guide wirefocused on the trapezius and control of the scopia. Observed complications were recorded and statistical analysis was performed. Results Fifty-one implants (49 patients) were reviewed. Mean follow-up was 2.1 years (1-5.7). Van Cappelle's test, pain, mobility, and grip and clamp strength improved significantly, as did the distance between the metacarpal head and the trapezius base; 96% of the patients returned in less than 6 months to their activities. Minor complications, 3 De Quervain's tendinopathy and 2 intra-operative metacarpal and 2 trapezium fractures were recorded, and one carpal tunnel syndrome. There was no dislocation, mobilization, or implant infection. Conclusions The functional results of the Isis® prosthesis are excellent in the short term, far exceeding the first year of 100% of survival. The complications that arose were minor and few. The anchorage and placement of the trapezial component guided by scopia seem to be crucial for the good result