Chronograms-phylogenies with branch lengths proportional to time-represent key data on timing of evolutionary events, allowing us to study natural processes in many areas of biological research. Chronograms also provide valuable information that can be used for education, science communication, and conservation policy decisions. Yet, achieving a high-quality reconstruction of a chronogram is a difficult and resource-consuming task.
View Article and Find Full Text PDFElectromyography (EMG) processing is a fundamental part of medical research. It offers the possibility of developing new devices and techniques for the diagnosis, treatment, care, and rehabilitation of patients, in most cases non-invasively. However, EMG signals are random, non-stationary, and non-linear, making their classification difficult.
View Article and Find Full Text PDFThe biological sciences community is increasingly recognizing the value of open, reproducible and transparent research practices for science and society at large. Despite this recognition, many researchers fail to share their data and code publicly. This pattern may arise from knowledge barriers about how to archive data and code, concerns about its reuse, and misaligned career incentives.
View Article and Find Full Text PDFBackground: Phylogenies are a key part of research in many areas of biology. Tools that automate some parts of the process of phylogenetic reconstruction, mainly molecular character matrix assembly, have been developed for the advantage of both specialists in the field of phylogenetics and non-specialists. However, interpretation of results, comparison with previously available phylogenetic hypotheses, and selection of one phylogeny for downstream analyses and discussion still impose difficulties to one that is not a specialist either on phylogenetic methods or on a particular group of study.
View Article and Find Full Text PDFThe Open Tree of Life project constructs a comprehensive, dynamic, and digitally available tree of life by synthesizing published phylogenetic trees along with taxonomic data. Open Tree of Life provides web-service application programming interfaces (APIs) to make the tree estimate, unified taxonomy, and input phylogenetic data available to anyone. Here, we describe the Python package opentree, which provides a user friendly Python wrapper for these APIs and a set of scripts and tutorials for straightforward downstream data analyses.
View Article and Find Full Text PDFAim: The purpose was to measure the effect of Oseltamivir on oxidative biomarkers and dopaminergic and serotonergic systems in brain of rats with induced hypotriglyceridemia by Bezafibrate.Male young Wistar rats were treated as follows: group 1, NaCl 0.9%, (Controls); group 2, Oseltamivir (100 mg/kg); group 3, single dose of Bezafibrate (150 mg/kg); group 4, four dose of Bezafibrate; group 5, single dose of Bezafibrate + Oseltamivir and group 6, four doses of Bezafibrate + Oseltamivir.
View Article and Find Full Text PDFA comprehensive phylogeny of species, i.e., a tree of life, has potential uses in a variety of contexts, including research, education, and public policy.
View Article and Find Full Text PDFThe genus Agave sensu lato contains ca. 211 described species, many of which are considered keystone species because of their ecological dominance and the quantity of resources they provide with their massive, nectar-rich inflorescences. The large diversity of Agave species has been hypothesized as being related to their reproductive strategy (predominantly monocarpic) and diverse pollinators (e.
View Article and Find Full Text PDFBackground And Aims: As angiosperms became one of the megadiverse groups of macroscopic eukaryotes, they forged modern ecosystems and promoted the evolution of extant terrestrial biota. Unequal distribution of species among lineages suggests that diversification, the process that ultimately determines species richness, acted differentially through angiosperm evolution.
Methods: We investigate how angiosperms became megadiverse by identifying the phylogenetic and temporal placement of exceptional radiations, by combining the most densely fossil-calibrated molecular clock phylogeny with a Bayesian model that identifies diversification shifts among evolutionary lineages and through time.
Arid biomes are particularly prominent in the Neotropics providing some of its most emblematic landscapes and a substantial part of its species diversity. To understand some of the evolutionary processes underlying the speciation of lineages in the Mexican Deserts, the diversification of Fouquieria is investigated, which includes eleven species, all endemic to the warm deserts and dry subtropical regions of North America. Using a phylogeny from plastid DNA sequences with samples of individuals from populations of all the species recognized in Fouquieria, we estimate divergence times, test for temporal diversification heterogeneity, test for geographical structure, and conduct ancestral area reconstruction.
View Article and Find Full Text PDFWe conducted a pilot study using Anchored Hybrid Enrichment to resolve relationships among a mostly Neotropical sage lineage that may have undergone a recent evolutionary radiation. Conventional markers (ITS, trnL-trnF and trnH-psbA) have not been able to resolve the relationships among species nor within portions of the backbone of the lineage. We sampled 12 representative species of subgenus Calosphace and included one species of Salvia's s.
View Article and Find Full Text PDFThe relationship between clade age and species richness has been increasingly used in macroevolutionary studies as evidence for ecologically versus time-dependent diversification processes. However, theory suggests that phylogenetic structure, age type (crown or stem age), and taxonomic delimitation can affect estimates of the age-richness correlation (ARC) considerably. We currently lack an integrative understanding of how these different factors affect ARCs, which in turn, obscures further interpretations.
View Article and Find Full Text PDFBackground And Aims: even though overweight and obesity (O/O) are stated diseases, there is still a claim for a so-called "healthy obese" phenotype. Only few reports have explored the presence of different metabolic phenotypes along the body mass index (BMI) range and their corresponding associations to cardiovascular risks.
Methods: as of BMI, and according to the presence of metabolic syndrome (MS) features (waist circumference, blood pressure, fasting glycemia, and lipid profile), phenotypes were determined.
The establishment of modern terrestrial life is indissociable from angiosperm evolution. While available molecular clock estimates of angiosperm age range from the Paleozoic to the Late Cretaceous, the fossil record is consistent with angiosperm diversification in the Early Cretaceous. The time-frame of angiosperm evolution is here estimated using a sample representing 87% of families and sequences of five plastid and nuclear markers, implementing penalized likelihood and Bayesian relaxed clocks.
View Article and Find Full Text PDFEscherichia coli occur as either free-living microorganisms, or within the colons of mammals and birds as pathogenic or commensal bacteria. Although the Mexican population of intestinal E. coli maintains high levels of genetic diversity, the exact mechanisms by which this occurs remain unknown.
View Article and Find Full Text PDFGac Med Mex
October 2011
Background: There is a lack of information on the characteristics of the medical attention delivered to Mexican patients with type 2 diabetes (T2D). Our aim was to describe the current state on the medical management of T2D in Mexico.
Methods: Among 17,232 patients included in the International Diabetes Management Practices Study (IDMPS), 2,620 (15%) corresponded to Mexico.
Background: The World Health Organization reports that waist circumference (WC) independent of weight or body mass index (BMI) predicts cardiovascular risk. We undertook this study to determine the change of prevalence in comorbidities associated with obesity and cardiovascular risk after favorably modifying WC.
Methods: We studied 153 nondiabetic patients with obesity (BMI =30 kg/m²) and WC in women =80 cm and in men =94 cm who entered a weight control program for 2 years.
Background: In the Mexican population we are unaware if the Framingham model is a better system than the SCORE system for stratifying cardiovascular risk. The present study was conducted to compare risk stratification with the Framingham tables using the same procedure but using the SCORE, with the aim of recommending the use of the most appropriate method.
Methods: We analyzed a database of apparently healthy workers from the Mexico City General Hospital included in the study group "PRIT" (Prevalencia de Factores de Riesgo de Infarto del Miocardio en Trabajadores del Hospital General de México) and we calculated the risk in each simultaneously with the Framingham method and the SCORE method.
Background: The management of type 2 diabetes mellitus is complicated by the presence of risk factors related to overweight and obesity, particularly visceral adiposity. However, weight loss and weight maintenance are difficult for patients with diabetes, and the benefits of dietary modifications are typically modest. Sibutramine is a serotonin- and norepinephrine-reuptake inhibitor that reduces food intake by inducing early satiety and attenuates the decrease in basal energy expenditure associated with weight loss.
View Article and Find Full Text PDFObjective: To assess the prevalence of coronary risk factors in 2,463 health-care workers at the General Hospital of Mexico.
Methods: The study participants--1,620 women (65.8%) and 843 men (34.
J Investig Allergol Clin Immunol
July 2004
Background: Previous studies have revealed the relationship between asthma and obesity, but the relationship with other markers of overweight and obesity has not yet been investigated.
Objective: To establish the relationship between asthma symptoms and simple anthropometric indexes (BMI, waist circumference (WC), and waist-to-hip ratio (WHR)) as markers of overweight in an adult Hispanic population.
Methods: The data were obtained from the PRIT (Prevalence of Cardiovascular Risks in General Hospital Workers) 2001 survey.
This 6-month randomized study evaluated the safety and efficacy of sibutramine in 57 overweight Hispanic patients with hypertension. Following a 2-week washout to confirm the diagnosis of hypertension, antihypertensive medication was adjusted to achieve a blood pressure less than 140/90 mm Hg before institution of either sibutramine 10 mg or placebo once a day. A body mass index in excess of 27 kg/m2 was required for entry.
View Article and Find Full Text PDFMetabolism
January 2002
The effects of troglitazone 400 or 600 mg/d on the glycemic control, very-low-density lipoprotein (VLDL), and high-density lipoprotein (HDL) subclass concentrations and plasminogen-activator inhibitor 1 (PAI-1) levels were assessed in patients with type 2 diabetes that had not been controlled with dietary treatment. This was a multicenter, open-label, parallel-groups study. It included a run-in 4-week diet period and a 24-week randomized treatment.
View Article and Find Full Text PDFInt J Obes Relat Metab Disord
December 2001
Objective: To determine values of simple anthropometric measurements which are associated with the presence of type 2 diabetes mellitus, hypertension and dyslipidaemia and to assess anthropometric cut-off values for predicting the likelihood of these chronic conditions in a Mexican population.
Design And Setting: The data were obtained from PRIT (Prevalence of Cardiovascular Risk Factors in General Hospital Workers) surveys from 1994 to 2000 adjusted to the structure of the overall Mexican population.
Subjects: A total of 2426 men and 5939 women aged 38.
Objective: To evaluate the weight gain after Sibutramine 10 mg daily discontinuation. To evaluate the effect of Sibutramine 10 mg daily in patients who were on a diet for 6 months.
Design: After a double-blind, placebo-controlled, parallel, prospective phase for 6 months, the treatments were crossed over and the patients continued in double-blind observation for another 6-month period.