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The coastal fishing of the snail Titanostrombus galeatus is carried out in some coastal countries of the Tropical Eastern Pacific. In this study, the individual growth of T. galeatus that are fished in the community at Punta Maldonado was estimated. The size structure was made using the shell length (SL), and the growth parameters were estimated through the five Schnute cases, where cases 1, 2, and 5 describe asymptotic growth and cases 3 and 4 describe nonasymptotic growth. The male population was more abundant than the females, with 398 and 322 specimens, respectively, but the females were larger (198 ± 9.66 mm). In general, the average SL during the two sampling cycles was 196 ± 9.44 mm; this size was not significantly different between the first and second cycles (P = 0.98). Females had a greater range of SL (170–267 mm) compared with males (170–240 mm). The lengths of both sexes showed significant differences between months (P < 0.05). The multinomial analysis showed a multimodal SL distribution, with one to three modal groups for females and males. In growth, cases 2 and 5 were the ones that best describe the growth in females, in males the best were cases 5 and 2. According to the best case (case 2) in females, the growth curve is sigmoidal. In males, the best case (case 5) describes growth according to an inverted exponential curve. In relation to the estimated growth parameters, females showed faster growth than males, analyzed using Kimura's test. The present investigation is the first that reports the growth for both sexes of T. galeatus using the five cases of the Schnute model. The information generated can be used for management purposes, as this species is not currently regulated in Mexico. [ABSTRACT FROM AUTHOR]

ABSTRACTThe parasite communities of marine fish in the tropical Pacific remain poorly studied. We did an initial study of the metazoan parasite communities of striped bonito Sarda orientalisfrom the Pacific coast of Mexico. Two hundred thirty individuals from two locations were collected between April 2017 and March 2018. Twenty-two metazoan parasite taxa (20 helminths and two Crustacea) were identified: one species of Monogenea, twelve of Digenea, one of Acanthocephala, two of Cestoda, four of Nematoda, one of Copepoda, and one of Isopoda. Didymozoid digeneans (six species) were the most frequent and abundant parasite species at both sampling locations. Parasite species richness at the component community level was similar in both locations (16–17 species). However, parasite community structure and species composition varied between them. Local fluctuations in some biotic (e.g. host feeding behaviour and body size) and abiotic environmental factors were probably responsible for these variations.

estudios recientes han reportado fenómenos trombóticos o coagulopatía en pacientes con COVID-19. Hay posiciones divergentes en cuanto a la prevención, el diagnóstico y el tratamiento de estos fenómenos, y la práctica clínica actual está basada únicamente en deducciones por extensión a partir de estudios retrospectivos, series de casos, estudios observacionales y guías internacionales desarrolladas previas a la pandemia.

ABSTRACTThe marine ecoregion known as the Mexican Pacific Transitional Zone (MPT) is a rich environment consisting of diverse coastal ecosystems with a great diversity of species, including bivalves, which have high ecological importance and perform a wide variety of environmental functions. Our objective was to document new records of bivalve species in the MPT and their geographic distribution. The study was conducted at 26 sites with rocky intertidal areas located in the Mexican states of Michoacan, Guerrero and Oaxaca. Semele (S.) californica, Petricola (P.) botulaand Parapholas acuminataare new records for the MPT; Crassostrea columbiensisis a new record for the coasts of Michoacan and Oaxaca. Plicatula spondylopsis, Chama corrugata, Diplodonta orbella, Sphenia fragilis, Juliacorbula bicarinata, Paraphola calva, Gastrochaena ovataand Lamychaena truncataare new records for the state of Guerrero. These new records demonstrate the need for more concentrated research efforts in the study of marine diversity, in particular to examine specific clades in this important biodiverse zone.Key policy insightsObtained results highlight the great variety of mollusc species that inhabit the Mexican Pacific Transitional Zone (MPT); however, they need further research.Knowledge of the diversity of mollusc in (MPT) allows us to enrich and update the taxonomic database for the Eastern Pacific Ocean.The taxonomic knowledge of bivalves will serve as the basis for the conservation and management of fishery resources occurring in the MPT.

Primary biliary cholangitis (PBC) is a chronic cholestatic autoimmune disease that disrupts the cholesterol metabolism. Our aim was to investigate the frequency of dyslipidemias and to evaluate the risk of cardiovascular events in a historic cohort of patients with PBC.

ABSTRACTThe rocky intertidal gastropods of the Marine Priority Region No. 32 (MPR 32) in the State of Guerrero are one of the most studied invertebrates, however, little is known about their diversity and distribution. Here we report 16 new records of gastropods collected at six sites of the rocky coast (MPR 32) located in the State of Guerrero, Mexico. These records represent extensions of distributional range for an assemblage of species in different geographical scales, of which two are new for Mexico, five for the Mexican Transitional Pacific, four for the State of Guerrero and five for the MPR 32. These new records reveal the need for increasing taxonomic and biogeographic studies on the marine diversity in Mexico, especially in the Mexican Transitional Pacific Ecoregion.

AbstractPopulation dynamics is a branch of ecology that studies temporal changes in the abundance of a population of organisms over time. This paper presents a study of the factors influencing population abundance of the acanthocephalan Neoechinorhynchus brentnickoliin Dormitator latifrons, the Pacific fat sleeper, from Tres Palos Lagoon. Fish were sampled from February 2012 to February 2013. A total of 688 adult fish were examined. The mean total length of fish varied significantly from 16.10 ± 1.93 cm (September 2012) to 20.78 ± 3.82 cm (August 2012). ‘Prevalence of acanthocephalans exceeded 90% in all months, and mature individuals were present year round, indicating that recruitment of helminths occurred throughout the year. Mean abundance ranged from 32.3 (July 2012) to 89.3 helminths per fish (March 2012) and was significantly lower in the rainy season. The body size of fish was the best predictor of acanthocephalan abundance in every month; larger fish harbored more acanthocephalans than smaller ones. Although parasite loads were high in some months (up to 500 acanthocephalans in one fish), obvious damage to the health of fish was not evident.

Eighty-six specimens representing 7 species of rodents from 9 localities in the state Zacatecas were examined for helminths. Only 5 host species were found to harbor at least 1 species: Chaetodipussp., Dipodomys merriami atronasus, Neotoma mexicana, Otospermophilus variegatus, and Peromyscussp.; in contrast Mus musculusand Reithrodontomyssp., were not parasitized. Three species of cestodes (Catenotaeniidae gen. sp., Hymenolepissp., and Raillietinasp.) and 7 nematodes (Gongylonemasp., Heteromyoxyuris longejector, Lamotheoxyuriscf. ackerti, Mastophorus dipodomis, Rauschtineriasp., Pterygodermatites dipodomis, and Trichuris dipodomis) were recorded. The intestine is the most parasitized (7 taxa) and trematodes were not found. The highest species richness was recorded in D. merriami atronasusfrom Rancho La Barranca (6 taxa), which also had the most sampling effort. H. longejectorin Chaetodipussp. from El Gordillo, showed the greatest mean abundance, and mean intensity values, followed by Rauschtineriasp. in O. variegatusfrom Morelos-Zacatecas Road. All species are new locality records, 14 new host records, and 2 taxa recorded for the first time in Mexico: Rauschtineriasp. and M. dipodomis. This is the first study of helminth parasites of rodents from Zacatecas.

The state of Guerrero, Mexico, has approximately 470 km of seashore but the marine fauna is not well known. The coastline has three marine areas for priority conservation of coastal and oceanic biodiversity, for which Comisión Nacional para la Conservación y Uso de la Biodiversidad (CONABIO) notes a distinct lack of knowledge in these areas. This study was carried out in a rocky intertidal middle zone from Playa ‘Majahua’, Acapulco, located south of Bahia de Puerto Marques. The objectives were to study: the species richness for classes Gastropoda, Bivalvia and Polyplacophora; the community structure from the representation of classes, families and genera; estimate density and species composition within a community; analyse size and structure of populations in the mollusc community; and estimate the diversity index. Three samplings were made in the intertidal middle zone in 2009. Ten square metres were sampled at each visit. Ninety-nine mollusc species were found to be represented, corresponding to 36 families. From all of these species, no record in Acapulco was found for 21 Gastropoda, 5 Bivalvia and 8 Polyplacophora species recorded. Gastropoda was the best represented; 1737 organisms were analysed with an estimated density of 86.8 organisms/m2and 31 species were dominant. Crucibullum umbrellawas the largest sized species. The diversity and equity index estimate in Majahua was the highest found for the rocky coast of Guerrero, indicating a mega-diverse area with great uniformity.

Background:Studies have reported an association between lower socioeconomic status (SES) and an elevated risk of ischemic stroke. It is unclear whether low SES is correlated with a specific etiology of ischemic stroke. Few studies have investigated the relationship in LMIC nations with wide disparities in SES. We analyzed data from a hospital-based stroke registry in Lima, Peru to determine the association between level of education as an indicator of SES and ischemic stroke etiology.Methods:All patients hospitalized with ischemic stroke at the National Institute of Neurologic Sciences from 2015-2018 were prospectively collected in a registry including demographics, risk factors, highest attained level of education, and diagnosed etiology of stroke by TOAST criteria. Association between ordinal level of education and stroke etiology was assessed after adjusting for differences in demographics and comorbidities by a multinomial multivariate logistic regression model.Results:A total of 461 cases of ischemic stroke were ascertained with 38.4% female and a mean age of 66.2 (SD 13.0). Stroke etiology was composed of 7.5% atherosclerotic, 29.7% cardioembolic, 14.2% small vessel disease, 24.7% cryptogenic, and 24.0% with incomplete evaluation. Higher education level strata had more men, younger mean age, and lower rates of hypertension. After multivariate adjustment, lower level of education was associated with an increased odds of large artery atherosclerosis compared to all non-cardioembolic etiologies (OR=2.27; 95% CI, 1.12-4.55). There was no significant association with level of education and odds of cardioembolic stroke after multivariate adjustment.Conclusion:Lower SES is associated with an increased odds of atherosclerotic etiology in patients with non-cardioembolic ischemic stroke. The associated between SES and stroke may be attributed to a higher burden of atherosclerotic disease in lower SES.

Molluscan communities were studied on two shores, one exposed and the other sheltered from wave action by determining the diversity, richness, density, dominance, and similarity of the groups of species found in the upper part of middle intertidal zone. The sample area per location and date was 20 m². The samples were taken quarterly during the year. Species richness was found to be 44 species for both sites combined. The exposed site had a greater richness (41 species) and lower density (64.2 organisms/m²), whereas the sheltered site showed a higher density (88.08 organisms/m²) and smaller richness (33 species). Thirty species (68.8%) were determined to be common. The exposed shore had more confined species. The Shannon-Wiener diversity index (H') was higher for the exposed site (3.165 bits/individual). A comparison of means by the Mann-Whitney tested indicated that the annual means of H' were equal between the two sites. Qualitative (Jaccard) and quantitative (Morisita-Horn) similarity scores were high at 0.682 and 0.622, respectively. The mean density of gastropods was the same at both locations, because bivalves showed significant differences with higher densities at the sheltered site. The malacologic community of the two sites was very similar. However, changes in richness and diversity over time were greater at the sheltered shore, while these changes were more gradual at the exposed shore, reflecting a greater stability of the malacologic community at the latter location. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of methylparathion under UV irradiation was monitored by polarography in an aqueous medium (pH 6.5) at 254 and 366 nm, and the effects of atmospheric oxygen and TiO2 on methylparathion were also looked at. Dissapearance of the methylparathion and appearance of two major electroactive degradation products were observed. The reaction rate constants for the process ranged from 3.55 × 10-5 to 5.69 × 10-5s-1, and the reaction showed pseudo-first-order kinetics. The methylparathion transformation did not depend on the experimental conditions. Spectroscopic and electrochemical data suggest the presence of p-nitrobenzoic acid as a common electroactive product.