Using regression tree analysis to determine size class intervals and sexual dimorphism in the Morelet's crocodile Crocodylus moreletii

Assignment of Morelet's crocodile Crocodylus moreletii individuals into size groups or classes based on ecological and morphological similarities has not yet been associated with species-specific ontogeny related changes. Age or size of first reproductive behavior is not precisely known for C. moreletii, but differences in allometric patterns and relative cranial size between juveniles and adults might be used as an indicator of sexual maturity. In this study, a regression tree analysis was used to investigate the relationship between age and body size in 1266 crocodiles by using both simple and generalized linear models, with gender and origin (captivity or wild) as factors. Total length (TL), snout–vent length (SVL) and cranial length (CL) were used as predictor variables and the logarithm of body mass as the response variable. Four length intervals with well-defined thresholds (514, 899 and 1497 mm of TL) were established using all three predictors (TL, SVL and CL). Relationship between SVL and TL was described, and a strong positive relationship (r2 = 0.98), unaffected by crocodile gender, was observed. The observed CL–TL and CL–SVL relationships were also positive but significantly different between males and females (p < 0.001) and length interval classes (p = 0.01). These results suggest that our estimated size thresholds seem to correspond to important ontogenetic changes in C. moreletii and that sexual maturity is closely related to size in this species, where sexual dimorphism in body length occurs, particularly in large individuals (size group IV)

Characterising a genetic stronghold amidst pervasive admixture: Morelet’s crocodiles (Crocodylus moreletii) in central Yucatan

When backcrosses are fertile, interbreeding between endangered taxa can lead to the admixture of gene pools under threat. One such case pertains to the Mesoamerican crocodile Crocodylus moreletii, a species which shows strong signatures of both recent hybridisation and historic intogression with the American crocodile C. acutus across large parts of its range. In the present paper, we use RAD-seq derived SNPs (4980 nuclear and seven mtDNA loci) to demonstrate that C. moreletii populations inhabiting the region of Calakmul in central Yucatan (Mexico) are rather unaffected by hybridization, despite being surrounded by coastal areas where pervasive admixture has previously been documented. All (based on fastSTRU CTU RE) and 96% (based on NGSadmix) of 84 genotyped individuals from 18 sampled waterbodies (locally termed aguadas) were free from nuclear introgression of C. acutus DNA at at threshold of 0.95. Seven individuals (8%) possessed a C. acutus mtDNA haplotype, five of which were derived from two adjacent, rather peripheral aguadas. Spatial inferences based on a DAPC and fineRADstructure further showed that the region of Calakmul is inhabited by three genetic clusters spanning across a set of distinct aguadas each. Taken together, our findings reveal that central Yucatan contains the currently largest documented stronghold of C. moreletii populations only marginally affected by introgression, which has major implications for the conservation management of this important flagship species

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Size, blood organochlorine pesticide concentrations and biochemical indicators measured in hawksbill sea turtles (Eretmochelys imbricata) nesting at Punta Xen (Campeche, Mexico) in August 2010

Data on the impact of environmental pollution on the homeostasis of sea turtles remains scarce, particularly in the southern Gulf of Mexico. As many municipalities along the coastline of the Yucatan Peninsula do not rely on a waste treatment plant, these organisms could be particularly vulnerable. We searched for relationships between the presence of organochlorine pesticides (OCP) and the level of several oxidative and pollutant stress indicators of the hawksbill sea turtle (Eretmochelys imbricata) during the 2010 nesting season at Punta Xen (Campeche, Mexico). Of the 30 sampled sea turtles, endosulfans, aldrin related (aldrin, endrin, dieldrin, endrin ketone, endrin aldehyde) and dichlorodiphenyldichloroethylene (DDT) families were detected in 17, 21 and 26, respectively. Significant correlation existed between the size of sea turtles with the concentration of methoxychlor, cholinesterase activity in plasma and heptachlors family, and catalase activity and hexachlorohexane family. Cholinesterase activity in washed erythrocytes and lipid peroxidation were positively correlated with glutathione reductase activity. Antioxidant enzyme actions seem adequate as no lipids damages were correlated with any OCPs. Future studies are necessary to evaluate the effect of OCPs on males of the area due to the significant detection of methoxychlor, which target endocrine functioning and increases its concentration with sea turtles size

Exposure biomarkers and organochloride pesticides in captive crododiles

editorial reviewe

A front-of-pack labelling system for food and beverages for Mexico: a strategy of healthy decision-making

The Mexican Ministry of Health requested the National Institute of Public Health to constitute a group of independent, free of conflict-of-interest academic experts on front-of-pack labelling (FOP). This group was instructed to created a positioning paper to contribute to the development of a FOP system for industrialized products that offers useful information for purchase decision making. This position paper uses the best available scientific evidence, and recommendations from experts of international organizations. The FOP proposal focuses on the contents of energy, nutrients, ingredients and components that if consumed in excess on the diet, can be harmful to people’s health, such as added sugars, sodium, total fat, saturated fat and energy. The academic expert group recommends the implementation of a FOP that provides an easy way to quickly assess the quality of a product. It is essential that this FOP provides direct, simple, visible and easily understandable information

Evidence-based clinical practice guidelines for the management of sedoanalgesia and delirium in critically ill adult patients

Dada la importancia del manejo de la sedación, analgesia y delirium en las unidades de cuidados intensivos, y con el fin de actualizar las guías publicadas anteriormente, se decidió elaborar una nueva guía de práctica clínica con los soportes, manejos e intervenciones más relevantes acordes con las publicaciones recientes. Para elaborar esta guía, se reunió un grupo de 24 intensivistas procedentes de 9 países de la Federación Panamericana e Ibérica de Sociedades de Medicina Crítica y Terapia Intensiva. Se acogió la propuesta del Grading of Recommendations Assessment, Development and Evaluation Working Group para emitir el grado de recomendación y evaluar la calidad de la evidencia. Se realizó una búsqueda sistemática de la literatura utilizándose: MEDLINE, las siguientes bases de datos de la biblioteca Cochrane: Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects, National Health Service Economic Evaluation Database, y la base de datos de Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS). Finalmente, se seleccionaron 438 referencias, permitiendo realizar 47 recomendaciones fuertes con evidencia alta y moderada, 14 recomendaciones condicionales con evidencia moderada y 65 recomendaciones condicionales con evidencia baja. Se confirma la importancia del manejo inicial y multimodal del dolor, se hace énfasis en la disminución de los niveles de sedación y la utilización de sedación profunda solo en casos específicos. Aumenta la evidencia y recomendaciones para el uso de medicamentos como dexmedetomidina, remifentanil, ketamina, entre otros.Given the importance of the management of sedation, analgesia and delirium in Intensive Care Units, and in order to update the previously published guidelines, a new clinical practice guide is presented, addressing the most relevant management and intervention aspects based on the recent literature. A group of 24 intensivists from 9 countries of the Pan-American and Iberian Federation of Societies of Critical Medicine and Intensive Therapy met to develop the guidelines. Assessment of evidence quality and recommendations was made according to the Grading of Recommendations Assessment, Development and Evaluation Working Group. A systematic search of the literature was carried out using MEDLINE, Cochrane Library databases such as the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects, the National Health Service Economic Evaluation Database and the database of Latin American and Caribbean Literature in Health Sciences (LILACS). A total of 438 references were selected. After consensus, 47 strong recommendations with high and moderate quality evidence, 14 conditional recommendations with moderate quality evidence, and 65 conditional recommendations with low quality evidence were established. Finally, the importance of initial and multimodal pain management was underscored. Emphasis was placed on decreasing sedation levels and the use of deep sedation only in specific cases. The evidence and recommendations for the use of drugs such as dexmedetomidine, remifentanil, ketamine and others were incremented. © 2019 Elsevier España, S.L.U. y SEMICYU

Compilación de Proyectos de Investigacion de 1984-2002

Instituto Politecnico Nacional. UPIICS