RESUMO
The Portezuelo Formation preserves an outstanding record of the upper Turonian - lower Coniacian. Despite the discovery of a significant quantity of sauropod fossil material from the formation, only two species have been formally described to date: Malarguesaurus florenciae and Futalognkosaurus dukei. Here we present new sauropod material mostly composed of non-articulated caudal vertebrae (MCF-PVPH 916 and 917) that belong to two titanosauriforms on the basis of the following features: anterior caudal vertebrae with procoelous-opisthoplatyan articulations, transverse processes that reach the posterior articular face of the centrum and neural spines with a transverse width of around 50% of their anteroposterior length; anterior and middle caudal vertebrae with the neural arch restricted to the anterior half of the centrum; middle caudal centra with circular cross-section. Phylogenetic analysis recovers the new material in close relation to Malarguesaurus within a monophyletic clade at the base of Somphospondyli. This clade shares large pedicel height with a vertical anterior border on the middle caudal vertebrae, a vertical orientation of the neural spines on the distalmost middle caudal vertebrae and proximalmost posterior caudal vertebrae, and subequal relative lengths of the proximal ulnar condylar processes. The specimens presented here are distinct not only from Futalognkosaurus, but also from other indeterminate titanosaurian remains from the same formation. However, there are no significant differences between the specimen MCF-PVPH 917 and Malarguesaurus, but there are differences between the posterior caudal vertebrae of MCF-PVPH 916 and Malarguesaurus, so they could be considered different species. Whilst we err on the side of caution in not naming new taxa here, the two specimens significantly expand what we know about sauropods in the Turonian-Coniacian ecosystems of Patagonia, which will continue to do so as more material is discovered.
Assuntos
Dinossauros , Fósseis , Filogenia , Animais , Dinossauros/anatomia & histologia , Argentina , Coluna Vertebral/anatomia & histologia , BiodiversidadeRESUMO
The study of thirty-two shed crowns from the Portezuelo Formation (middle Turonian-late Coniacian) at the Sierra del Portezuelo locality, reveals six distinct tooth morphotypes identified through cladistic, discriminant, and cluster analyses. Two morphotypes were identified as belonging to Megaraptoridae, three to Abelisauridae, one to Abelisauroidea, and one to Alvarezsauridae. Additionally, two of the morphotypes exhibit a combination of dental features typically found in megaraptorid and abelisauridtheropods. These results suggest a greater diversity of theropods in the original ecosystem than previously thought, including the presence of a second morphotype of megaraptorid and alvarezsaurid previously undocumented in this formation. Furthermore, the existence of Morphotype 6 indicates the potential coexistence of medium-sized abelisauroids alongside larger abelisaurids in the same ecosystem. These findings underscore the importance of future expeditions to the Sierra del Portezuelo locality to further our understanding of these previously unknown theropod species.
Assuntos
Fósseis , Dente , Animais , Dente/anatomia & histologia , Biodiversidade , Argentina , FilogeniaRESUMO
BACKGROUND: Radial arterial catheters (RAC) are commonly used in emergency services and intensive care units (ICU) for continuous invasive monitoring of blood pressure and arterial blood gas sampling. Complications associated with RAC are rare. Regarding length of RAC catheters and complications, few studies were found in the literature. The present study seeks to provide health care professionals with scientific evidence to select an optimal length of RAC, based on the difference in the incidence of complications between ultrasound-guided catheters of the same diameter but different lengths. METHODS: Observational, descriptive, retrospective study. Patients older than 17 years admitted to the emergency department or ICU were included. RAC were placed with diameters of 20 gauge, between 5 and 8 cm (Arrow-Teleflex), and 22 gauge diameters between 4 and 8 cm (Vygon). Univariate analysis was made to determine behavior of the numerical variables. Normality of variables was determined through a Shapiro-Wilk-test. Qualitative variables were expressed in percentages, quantitative variables in means and standard deviation, or with median and quartiles in the case of a non-normal distribution. Chi-square or Fisher method was used for qualitative variables and the t-test for symmetric quantitative variables. Asymmetric distributions were processed with the Mann-Whitney U test. A value p < 0.05 was considered statistically significant. The statistical analysis was performed with Stata 14.1 program. RESULTS: About 793 RAC were placed between 2016 and 2019 were included, median age was 60 (37-73) (RIQ) years, 49% male. Complications were reported in all groups on average 17.5%, the most frequent being dysfunction/occlusion of the catheter. Given complications of the same diameter and different catheter lengths, there were no statistical differences between groups. CONCLUSION: Selecting one length or another with a catheter of the same diameter does not have statistically significant differences, in terms of the complications this device may cause-meaning that size does not matter.
Assuntos
Cateterismo Periférico , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Estudos Retrospectivos , Cateterismo Periférico/efeitos adversos , Cateterismo Periférico/métodos , Cateteres de Demora , Ultrassonografia , CânulaRESUMO
Proteins are the workhorses of the cell, yet they carry great potential for harm via misfolding and aggregation. Despite the dangers, proteins are sometimes born de novo from non-coding DNA. Proteins are more likely to be born from non-coding regions that produce peptides that do little to no harm when translated than from regions that produce harmful peptides. To investigate which newborn proteins are most likely to "first, do no harm", we estimate fitnesses from an experiment that competed Escherichia coli lineages that each expressed a unique random peptide. A variety of peptide metrics significantly predict lineage fitness, but this predictive power stems from simple amino acid frequencies rather than the ordering of amino acids. Amino acids that are smaller and that promote intrinsic structural disorder have more benign fitness effects. We validate that the amino acids that indicate benign effects in random peptides expressed in E. coli also do so in an independent dataset of random N-terminal tags in which it is possible to control for expression level. The same amino acids are also enriched in young animal proteins.
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OBJECTIVE: Breast cancer is the most common cancer diagnosed in women, and microcalcification (MCC) clusters act as an early indicator. Thus, the detection of MCCs plays an important role in diagnosing breast cancer. METHODS: This paper presents a methodology for mammogram preprocessing and MCC detection. The preprocessing method employs automatic artefact deletion and pectoral muscle removal based on region-growing segmentation and polynomial contour fitting. The MCC detection method uses a convolutional neural network for region-of-interest (ROI) classification, along with morphological operations and wavelet reconstruction to reduce false positives (FPs). RESULTS: The methodology was evaluated using the mini-MIAS and UTP datasets in terms of segmentation accuracy in the preprocessing phase, as well as sensitivity and the mean FP rate per image in the MCC detection phase. With the mini-MIAS dataset, the proposed methods achieved accuracy scores of 99% for breast segmentation and 95% for pectoral segmentation, a sensitivity score of 82% for MCC detection, and an FP rate per image of 3.27. With the UTP dataset, the methods achieved accuracy scores of 97% for breast segmentation and 91% for pectoral segmentation, a sensitivity score of 78% for MCC detection, and an FP rate per image of 0.74. CONCLUSIONS: The proposed preprocessing method outperformed the state-of-the-art methods for breast segmentation and achieved relatively good results for pectoral muscle removal. Furthermore, the MCC detection module achieved the highest test accuracy in identifying potential ROIs with MCCs compared to other methods.
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The extended evolutionary synthesis invokes a role for development in shaping adaptive evolution, which in population genetics terms corresponds to mutation-biased adaptation. Critics have claimed that clonal interference makes mutation-biased adaptation rare. We consider the behaviour of two simultaneously adapting traits, one with larger mutation rate U, the other with larger selection coefficient s, using asexual travelling wave models. We find that adaptation is dominated by whichever trait has the faster rate of adaptation v in isolation, with the other trait subject to evolutionary stalling. Reviewing empirical claims for mutation-biased adaptation, we find that not all occur in the 'origin-fixation' regime of population genetics where v is only twice as sensitive to s as to U. In some cases, differences in U are at least ten to twelve times larger than differences in s, as needed to cause mutation-biased adaptation even in the 'multiple mutations' regime. Surprisingly, when U > s in the 'diffusive-mutation' regime, the required sensitivity ratio is also only two, despite pervasive clonal interference. Given two traits with identical v, the benefit of having higher s is surprisingly small, occurring largely when one trait is at the boundary between the origin-fixation and multiple mutations regimes.
Assuntos
Adaptação Fisiológica/genética , Genética Populacional , Taxa de Mutação , Mutação , Reprodução Assexuada/genéticaRESUMO
Genetic covariances represent a combination of pleiotropy and linkage disequilibrium, shaped by the population's history. Observed genetic covariance is most often interpreted in pleiotropic terms. In particular, functional constraints restricting which phenotypes are physically possible can lead to a stable G matrix with high genetic variance in fitness-associated traits, and high pleiotropic negative covariance along the phenotypic curve of constraint. In contrast, population genetic models of relative fitness assume endless adaptation without constraint, through a series of selective sweeps that are well described by recent traveling wave models. We describe the implications of such population genetic models for the G matrix when pleiotropy is excluded by design, such that all covariance comes from linkage disequilibrium. The G matrix is far less stable than has previously been found, fluctuating over the timescale of selective sweeps. However, its orientation is relatively stable, corresponding to high genetic variance in fitness-associated traits and strong negative covariance-the same pattern often interpreted in terms of pleiotropic constraints but caused instead by linkage disequilibrium. We find that different mechanisms drive the instabilities along vs. perpendicular to the fitness gradient. The origin of linkage disequilibrium is not drift, but small amounts of linkage disequilibrium are instead introduced by mutation and then amplified during competing selective sweeps. This illustrates the need to integrate a broader range of population genetic phenomena into quantitative genetics.
Assuntos
Aptidão Genética , Haploidia , Características de História de Vida , Modelos Genéticos , Seleção Genética , Adaptação Fisiológica , Escherichia coli , Desequilíbrio de Ligação , Polimorfismo Genético , Reprodução Assexuada , Saccharomyces cerevisiaeRESUMO
Exposure to maternal anti-Ro (SS-A) and anti-La (SS-B) antibodies is a well-described risk factor for the development of fetal atrioventricular (AV) block. The role of maternal fluorinated steroids in the treatment and prevention of antibody-mediated fetal AV block is controversial. Fetal atrial flutter has rarely been described in association with maternal antibodies. This report describes a case of fetal exposure to maternal anti-Ro antibodies with associated second-degree AV block and atrial flutter. Interestingly, the reported patient had 2:1 AV conduction during both normal atrial rates (consistent with AV node conduction disease) and episodes of flutter (consistent with physiologic AV node functionality). The fetus was treated with transplacental digoxin and dexamethasone, which resolved both rhythm disturbances. The case report is followed by a brief discussion of AV block and atrial flutter associated with maternal antibody exposure.