Ulcerative Unilateral Tinea Manuum Caused by Nannizzia gypsea.

Dermatophytes, fungi specialized in keratin degradation, are key agents in skin infections, commonly referred to as tineas. Tinea manuum, affecting the hands, typically presents in noninflammatory or inflammatory forms, with ulcerative manifestations rarely reported. Nannizzia gypsea, a relatively uncommon cause of tineas, exhibits variable prevalence influenced by geographic factors. This study investigates a case of Ulcerative Unilateral Tinea Manuum caused by N. gypsea, aiming to explore the differential diagnosis, pathogenesis, and management. A 23-year-old female from the Yucatan Peninsula presented with an ulcerated lesion on her left hand. Initially suspected as Leishmaniasis, subsequent examination revealed tinea manuum. The study discusses differential diagnoses, highlighting the rarity of ulcerative presentations in dermatophytosis, and explores potential pathogenic mechanisms. This case underscores the importance of considering dermatophytes in ulcerative skin lesions and suggests a comprehensive diagnostic approach, particularly in endemic regions.

Biosynthetic potential of the sediment microbial subcommunities of an unexplored karst ecosystem and its ecological implications.

Microbial communities from various environments have been studied in the quest for new natural products with a broad range of applications in medicine and biotechnology. We employed an enrichment method and genome mining tools to examine the biosynthetic potential of microbial communities in the sediments of a coastal sinkhole within the karst ecosystem of the Yucatán Peninsula, Mexico. Our investigation led to the detection of 203 biosynthetic gene clusters (BGCs) and 55 secondary metabolites (SMs) within 35 high-quality metagenome-assembled genomes (MAGs) derived from these subcommunities. The most abundant types of BGCs were Terpene, Nonribosomal peptide-synthetase, and Type III polyketide synthase. Some of the in silico identified BGCs and SMs have been previously reported to exhibit biological activities against pathogenic bacteria and fungi. Others could play significant roles in the sinkhole ecosystem, such as iron solubilization and osmotic stress protection. Interestingly, 75% of the BGCs showed no sequence homology with bacterial BGCs previously reported in the MiBIG database. This suggests that the microbial communities in this environment could be an untapped source of genes encoding novel specialized compounds. The majority of the BGCs were identified in pathways found in the genus Virgibacillus, followed by Sporosarcina, Siminovitchia, Rhodococcus, and Halomonas. The latter, along with Paraclostridium and Lysinibacillus, had the highest number of identified BGC types. This study offers fresh insights into the potential ecological role of SMs from sediment microbial communities in an unexplored environment, underscoring their value as a source of novel natural products.

Predicting future climate change impacts on the potential distribution of the black howler monkey (Alouatta pigra): an endangered arboreal primate.

Climate change is one of the main factors affecting biodiversity worldwide at an alarming rate. In addition to increases in global extreme weather events, melting of polar ice caps, and subsequent sea level rise, climate change might shift the geographic distribution of species. In recent years, interest in understanding the effects of climate change on species distribution has increased, including species which depend greatly on forest cover for survival, such as strictly arboreal primates. Here, we generate a series of species distribution models (SDMs) to evaluate future projections under different climate change scenarios on the distribution of the black howler monkey (Alouatta pigra), an endemic endangered primate species. Using SDMs, we assessed current and future projections of their potential distribution for three Social Economic Paths (SSPs) for the years 2030, 2050, 2070, and 2090. Specifically, we found that precipitation seasonality (BIO15, 30.8%), isothermality (BIO3, 25.4%), and mean diurnal range (BIO2, 19.7.%) are the main factors affecting A. pigra distribution. The future climate change models suggested a decrease in the potential distribution of A. pigra by projected scenarios (from - 1.23 to - 12.66%). The highly suitable area was the most affected above all in the more pessimist scenario most likely related to habitat fragmentation. Our study provides new insights into the potential future distribution and suitable habitats of Alouatta pigra. Such information could be used by local communities, governments, and non-governmental organizations for conservation planning of this primate species.

Transcriptional Response of Vitellogenin Gene in Flatfish to Environmental Pollutants from Two Regions of the Gulf of Mexico.

The present study evaluates the endocrine effect in flatfish through vitellogenin (vtg) gene expression and its association with pollutants data obtained from fish muscle and sediment from two regions in the Gulf of Mexico (GoM): Perdido Fold Belt (northwestern) and the Yucatan Peninsula (southeast). The results revealed induction of vtg in male flatfish in both geographical regions with different levels and patterns of distribution per oceanographic campaign (OC). In the Perdido Fold Belt, vtg was observed in male fish during four OC (carried out in 2016 and 2017), positively associated with Pb, V, Cd and bile metabolites (hydroxynaphthalene and hydroxyphenanthrene). In the Yucatan Peninsula, the induction of vtg in males was also detected in three OC (carried out in 2016 and 2018) mainly associated with Ni, Pb, Al, Cd, V and polycyclic aromatic hydrocarbons. Ultimately, estrogenic alterations could affect reproductive capacity of male flatfish in the GoM.

Entomological Survey and Leishmania (Leishmania) mexicana Prevalence in Sand Fly Species during an Outbreak of Cutaneous Leishmaniasis in Quintana Roo State, Mexico.

(1) Background: Localized cutaneous leishmaniasis is a neglected vector-borne disease that has become a serious public health problem in the Yucatan Peninsula. Although more than 60% of cases originate from the state of Quintana Roo, it is one of the least explored areas in terms of incriminating vectors of the Leishmania parasite. Additionally, cases of leishmaniasis have increased substantially in that region in recent years. For this reason, we explored and provided primary evidence of Leishmania DNA in sand fly species from four localities during outbreaks of leishmaniasis in Quintana Roo. We also contributed information on the regional genetic diversity of Leishmania parasites. (2) Methods: Sand flies were collected during several periods from November 2022 to April 2023 using Mosquito Light Circle and Shannon traps, as well as an active entomological search in refuges. For Leishmania detection, we amplified a fragment of 300-350 bp of the internal transcribed spacer subunit 1 (ITS-1). (3) Results: Of the 242 females collected, we detected Leishmania DNA in 25 specimens represented by Bichromomyia olmeca (1), Psathyromyia shannoni (17), Lutzomyia cruciata (4), Psathyromyia undulata (2), and Dampfomyia deleoni (1). The detection of Leishmania in these last two species represents new records for the Yucatan Peninsula and for Mexico. Leishmania (Leishmania) mexicana was the only species detected in the Phlebotominae species, with prevalence values that ranked between 7.41% and 33.33% from specimens collected in the sylvatic areas of Cozumel Island and Petcacab. (4) Conclusions: This study provides the first evidence of infection of Da. deleoni and Pa. undulata by L. (L.) Mexicana. In addition, the presence of three dominant haplotypes in all the evaluated localities was evidenced using the analysis of genetic diversity, and the locality of Petcacab was the one with the circulation of two new haplotypes not previously described in Mexico or neighboring countries. These results highlight the importance of intensive epidemiological surveillance due to the dynamics of transmission of Leishmania between different species.

Stephanostomum minankisi n. sp. (Digenea: Acanthocolpidae) from dusky flounder Syacium papillosum (Paralichthydae) from southern Gulf of Mexico: A new species without spines?

A new species of the genus Stephanostomum is described for the southeastern Gulf of Mexico based on morphological and nucleotide evidence. Stephanostomum minankisi n. sp. infects the intestine of the dusky flounder Syacium papillosum in the Yucatan Continental Shelf, Mexico (Yucatan Peninsula). Sequences of the 28S ribosomal gene were obtained and compared with available sequences of the other species and genera of the families Acanthocolpidae and Brachycladiidae from GenBank. A phylogenetic analysis was conducted, including 39 sequences, 26 of which represented 21 species and six genera of the family Acanthocolpidae. The new species is characterized by the absence of circumoral spines and spines on the tegument. Nonetheless, scanning electron microscopy consistently revealed the pits of 52 circumoral spines distributed in a double row with 26 spines each, and forebody spined. Other distinctive features of this species are testes in contact (sometimes overlapping), the vitellaria running along the body lateral fields to the mid-level of the cirrus-sac, pars prostatica and ejaculatory duct similar in length, and uroproct present. The phylogenetic tree showed that the three species found as parasites of dusky flounder (the new adult species and two in metacercaria stages) were grouped into two different clades. S. minankisi n. sp. was the sister species of Stephanostomum sp. 1 (Bt = 56) and formed a clade with S. tantabiddii, supported by high bootstrap values (100).

Seguimiento de la actividad clínica y del daño orgánico acumulado en una cohorte de pacientes con lupus eritematoso sistémico de la península de Yucatán, México (1995-2016) / Follow-up of clinical activity and accumulated organic damage in a cohort of patients with Systemic Lupus Erythematosus from the Yucatán peninsula, México (1995-2016)

Introducción: El lupus eritematoso sistémico (LES) es una enfermedad autoinmune con severidad variable, frecuente en individuos hispanos y afroamericanos. Objetivo: Conocer la actividad clínica y el daño acumulado, así como la prevalencia e incidencia, en una cohorte dinámica de pacientes con LES de la península de Yucatán (1995 a 2016). Pacientes y métodos: Se analizaron 200 pacientes con LES, beneficiarios del servicio médico del Hospital Regional ISSSTE de Mérida, Yucatán, durante 22 años. Se evaluó la actividad de la enfermedad y el daño acumulado mediante la escala MEX-SLEDAI y SLICC-ACR-DI, respectivamente, y su correlación con variables clínicas y demográficas. Resultados: Se analizaron 185 pacientes mujeres y 15 hombres. Los índices promedio de actividad y daño acumulado durante el seguimiento fueron de 4,63 y 1,10, respectivamente. El índice de actividad se observó significativamente menor en las mujeres respecto de los hombres (4,36 vs. 7,43), y el daño acumulado no presentó diferencia por sexo. Las manifestaciones asociadas con mayor actividad fueron las mucocutáneas y articulares, y los órganos con mayor daño acumulado el musculoesquelético, el neurológico y el gonadal. Se encontró relación de los índices con el tiempo de evolución, las remisiones/reactivaciones y la actividad persistente. La mortalidad se relacionó con actividad persistente por complicaciones vasculares sistémicas e insuficiencia renal y hepática. La incidencia y prevalencia anual del LES calculada fue de 2,86% y 48,43% en la península de Yucatán. Conclusiones: Los pacientes presentaron actividad persistente, con reactivaciones leves a moderadas y daño acumulado más agresivo en hombres. La actividad clínica disminuye e incrementa el daño acumulado a mayor tiempo de evolución, con menor afección renal y mayor sobrevida, lo que sugiere un curso más benigno en la población de la península de Yucatán.(AU)

IntroductionSystemic lupus erythematosus (SLE) is an autoimmune with variable severity, common in Hispanic and African-American individuals.Objective: To know the clinical activity and the accumulated damage, as well as the prevalence and incidence, in a dynamic cohort of patients with SLE from the Yucatan Peninsula (1995-2016). Patients and methods: A cohort of 200 patients with SLE, medical service beneficiaries of the ISSSTE Regional Hospital of Mérida, Yucatán, was analyzed for 22 years. Disease activity and accumulated damage were evaluated using the MEX-SLEDAI scale and the SLICC-ACR-DI, respectively, and its correlation with clinical and demographic variables. Results: 185 female and 15 male patients were analyzed. Average accumulated damage and activity indices during follow-up were 4.63 and 1.10, respectively. The activity index was significantly lower in females compared to males (4.36 vs 7.43), and the accumulated damage did not present a difference by sex. The manifestations associated with greater activity were the mucocutaneous and articular ones, and the organs with the greatest accumulated damage were the musculoskeletal, neurological and gonadal. A relationship between the indices was found with the evolution time, remissions / reactivations, and persistent activity. Mortality was related to persistent activity due to systemic vascular complications and kidney and liver failure. The annual incidence and prevalence of SLE calculated was 2.86% and 48.43% in Yucatán Peninsula. Conclusions: The patients presented persistent activity, with mild to moderate reactivations, and accumulated damage more aggressive in men. The clinical activity decreases and increases the accumulated damage at a longer evolution time, with less kidney disease and greater survival, which suggests a more benign course in the population of the Yucatan Peninsula.(AU)

Antifungal Potential of Marine Organisms of the Yucatan Peninsula (Mexico) against Medically Important Candida spp.

Invasive fungal infections represent a global health threat. They are associated with high mortality and morbidity rates, partly due to the ineffectiveness of the available antifungal agents. The rampant increase in infections recalcitrant to the current antifungals has worsened this scenario and made the discovery of new and more effective antifungals a pressing health issue. In this study, 65 extracts from marine organisms of the Yucatan Peninsula, Mexico, were screened for antifungal activity against Candida albicans and Candida glabrata, two of the most prevalent fungal species that cause nosocomial invasive fungal infections worldwide. A total of 51 sponges, 13 ascidians and 1 gorgonian were collected from the coral reef and mangrove forest in the Yucatan Peninsula (Mexico) and extracted with organic solvents. Nine crude extracts showed potent antifungal activity, of which four extracts from the sponge species Aiolochroia crassa, Amphimedon compressa, Monanchora arbuscula and Agelas citrina had promising activity against Candida spp. Bioassay-guided fractionation of the M. arbuscula extract revealed the remarkable fungicidal activity of some fractions. Analysis of the chemical composition of one of the most active fractions by UHPLC-HRMS and NMR indicated the presence of mirabilin B and penaresidin B, and their contribution to the observed antifungal activity is discussed. Overall, this work highlights marine organisms of the Yucatan Peninsula as important reservoirs of natural products with promising fungicidal activity, which may greatly advance the treatment of invasive fungal infections, especially those afflicting immunosuppressed patients.

Hawksbill Sea Turtle (Eretmochelys imbricata) Blood and Eggs Organochlorine Pesticides Concentrations and Embryonic Development in a Nesting Area (Yucatan Peninsula, Mexico).

Environmental contaminants with chemical origins, such as organochlorine pesticides (OCPs) have major impacts on the health of marine animals, including sea turtles, due to the bioaccumulation of those substances by transference throughout the food chain. The effects of environmental pollution on the health of marine turtles are very important for management strategies and conservation. During recent decades, the south Gulf of Mexico and the Yucatan Peninsula have suffered from increasingly frequent disturbances from continental landmasses, river systems, urban wastewater runoff, port areas, tourism, industrial activities, pesticides from agricultural use, and other pollutants, such as metals, persistent organic pollutants (POPs) and hydrocarbons (from the oil industry activities), which contaminate water and sediments and worsen the environmental quality of the marine ecosystem in this region. In this study, we assessed the concentrations of OCPs in the blood and eggs of 60 hawksbill turtles (Eretmochelys imbricata) nesting at the Punta Xen turtle camp, and their effects on the nesting population's reproductive performance: specifically, maternal transfer and embryonic development were analyzed. Hematologic characteristics, including packed cell volume, white blood cell count, red blood cell count, and haemoglobin levels, and plasma chemistry values, including creatinine, blood urea nitrogen, uric acid, triglyceride, total cholesterol and glucose, were also measured. The general health of the turtles in this study, as well as their levels of urea, serum creatinine, glucose, uric, acid, cholesterol, and triglyceride, fell within normal ranges and was similar to other normal values, which could indicate the turtles' good energy levels and body conditions for nest-building activity, with all of the turtles able to successfully come ashore to nest. All the same, the obtained results also indicate that OCPs affect the nesting and reproductive performance of the hawksbill turtles, as well as their fertility and the development of the population of eggs and reproductive performance, specifically in terms of maternal transference and embryonic development. There were significant differences in the concentrations of OCPs (ΣHCHs and ΣDienes) between maternal blood and eggs, indicating that these chemicals are transferred from nesting females to eggs and, ultimately, to hatchlings. OCPs may, therefore, have an effect on the health and reproductive performance of hawksbill turtles, both in terms of their fertility and egg development. Conservation strategies need to be species-specific, due to differences in feeding, and address the reasons for any decline, focusing on regional assessments. Thus, accurate and comparable monitoring data are necessary, which requires the standardization of monitoring protocols.

Follow-up of clinical activity and accumulated organic damage in a cohort of patients with systemic lupus erythematosus from the Yucatán Peninsula, Mexico (1995-2016).

INTRODUCTION: Systemic lupus erythematosus (SLE) is an autoimmune with variable severity, common in Hispanic and African-American individuals. OBJECTIVE: To know the clinical activity and the accumulated damage, as well as the prevalence and incidence, in a dynamic cohort of patients with SLE from the Yucatan Peninsula (1995-2016). PATIENTS AND METHODS: A cohort of 200 patients with SLE, medical service beneficiaries of the ISSSTE Regional Hospital of Mérida, Yucatán, was analysed for 22 years. Disease activity and accumulated damage were evaluated using the MEX-SLEDAI scale and the SLICC-ACR-DI, respectively, and its correlation with clinical and demographic variables. RESULTS: 185 female and 15 male patients were analysed. Average accumulated damage and activity indices during follow-up were 4.63 and 1.10, respectively. The activity index was significantly lower in females compared to males (4.36 vs 7.43), and the accumulated damage did not present a difference by sex. The manifestations associated with greater activity were the mucocutaneous and articular ones, and the organs with the greatest accumulated damage were the musculoskeletal, neurological and gonadal. A relationship between the indices was found with the evolution time, remissions/reactivations, and persistent activity. Mortality was related to persistent activity due to systemic vascular complications and kidney and liver failure. The annual incidence and prevalence of SLE calculated was 2.86% and 48.43% in Yucatán Peninsula. CONCLUSIONS: The patients presented persistent activity, with mild to moderate reactivations, and accumulated damage more aggressive in men. The clinical activity decreases and increases the accumulated damage at a longer evolution time, with less kidney disease and greater survival, which suggests a more benign course in the population of the Yucatan Peninsula.

Effect of extracts from several sponges of Yucatan Coast on Giardia lamblia and preliminary chemical investigation of the bioactive extract of Haliclona (Reinera) tubifera.

In this study, twenty-four organic extracts from six marine sponge species, collected at shallows of Yucatan, Mexico, were evaluated against Giardia lamblia trophozoites and Vero cells. The dichloromethane and hexane extracts of Haliclona tubifera exhibited the highest antigiardiasic activity (IC50 = 1.00 and 2.11 µg/mL, respectively), as well as high selectivity (SI = 41.8 and > 47.4, respectively), while ethyl acetate and methanol extracts of Cinachyrella alloclada, and methanol extract of Suberites aurantiaca showed moderate activity. Contrastingly, the extracts of Halichondria magniculosa and Oceanapia nodosa were considered non actives. Consequently, the dichloromethane extract of H. tubifera were subject to an exploratory chemical study, isolating cholesterol, two benzaldehyde derivatives, three benzoic acid derivatives, cytosine, and thymine.

Consequences of introgression and gene flow on the genetic structure and diversity of Lima bean (Phaseolus lunatus L.) in its Mesoamerican diversity area.

We evaluated the role of gene flow and wild-crop introgression on the structure and genetic diversity of Lima bean (Phaseolus lunatus) in the Yucatan Peninsula, an important Mesoamerican diversity area for this crop, using a genotyping-by-sequencing approach (15,168 SNP markers) and two scales. At the local scale, STRUCTURE and NGSEP analyses showed predominantly crop-to-wild introgression, but also evidence of a bidirectional gene flow in the two wild-weedy-crop complexes studied (Itzinté and Dzitnup). The ABBA-BABA tests showed a higher introgression in Itzinté (the older complex) than in Dzitnup (the younger one); at the allelic level, the wild-crop introgression in Itzinté was similar in both directions, in Dzitnup it was higher from crop-to-wild; and at the chromosomal level, introgression in Itzinté was from wild-to-crop, whereas in Dzitnup it occured in the opposite direction. Also, we found H E values slightly higher in the domesticated accessions than in the wild ones, in both complexes (Itzinté: wild = 0.31, domesticated = 0.34; Dzinup: wild = 0.27, domesticated = 0.36), but %P and π estimators were higher in the wild accessions than in the domesticated ones. At a regional scale, STRUCTURE and MIGRATE showed a low gene flow, predominantly from crop-to-wild; and STRUCTURE, Neighbor-Joining and PCoA analyses indicated the existence of two wild groups and one domesticated group, with a marked genetic structure based in the existence of domesticated MI and wild MII gene pools. Also, at the regional scale, we found a higher genetic diversity in the wild accessions than in the domesticated ones, in all estimators used (e.g., H E = 0.27 and H E = 0.17, respectively). Our results indicate that gene flow and introgression are playing an important role at the local scale, but its consequences on the structure and genetic diversity of the Lima bean are not clearly reflected at the regional scale, where diversity patterns between wild and domesticated populations could be reflecting historical events.

New Complex of Cryptic Species Discovered in Genus Biblis (Papilionoidea: Nymphalidae: Biblidinae) in Mexico.

Our research focuses on demonstrating the existence of cryptic species named under Biblis aganisa Boisduval. We used COI sequences to delimit Biblis species for Mexico using species delimitation analyses and examined phylogenetic relationships with sequences from Mexico, Costa Rica, Argentina, USA, and Guana Island using a Bayesian inference tree. We performed a discriminant analysis with quantitative traits using female and male wing and genitalia, and a tree of maximum parsimony based on 39 qualitative characters of wings, head, and male genitalia. The results were congruent in the three analyses. Three groups were formed based on DNA, ECO 01 + DHJ02, ECO 02 + DHJ01, and ECO 03. The characters that contributed over 50% separation were for wings: wing length, anal margin length, and distance from the band to the outer margin; for male genitalia, angle of the integument, uncus, and the length of the hypandrium, while for females, it was the angle of the anteapophysis and the length of the abdomen. For the analysis of qualitative characters, a tree of maximum parsimony was obtained where 20 characters were informative. We confirmed the existence of three cryptic Biblis species in Mexico, two not yet described, and one corresponding to B. aganisa (ECO 02), which is sympatric in Oaxaca and Sinaloa (ECO 03) and in the Yucatan Peninsula (ECO 01).

The complete mitochondrial genome of the Mexican-endemic cavefish Ophisternoninfernale (Synbranchiformes, Synbranchidae): insights on patterns of selection and implications for synbranchiform phylogenetics.

Ophisternoninfernale is one of the 200+ troglobitic fish species worldwide, and one of the two cave-dwelling fishes endemic to the karstic aquifer of the Yucatán Peninsula, Mexico. Because of its elusive nature and the relative inaccessibility of its habitat, there is virtually no genetic information on this enigmatic fish. Herein we report the complete mitochondrial genome of O.infernale, which overall exhibits a configuration comparable to that of other synbranchiforms as well as of more distantly related teleosts. The KA/KS ratio indicates that most mtDNA PCGs in synbranchiforms have evolved under strong purifying selection, preventing major structural and functional protein changes. The few instances of PCGs under positive selection might be related to adaptation to decreased oxygen availability. Phylogenetic analysis of mtDNA comparative data from synbranchiforms and closely related taxa (including the indostomid Indostomusparadoxus) corroborate the notion that indostomids are more closely related to synbranchiforms than to gasterosteoids, but without rendering the former paraphyletic. Our phylogenetic results also suggest that New World species of Ophisternon might be more closely related to Synbranchus than to the remaining Ophisternon species. This novel phylogenetic hypothesis, however, should be further tested in the context of a comprehensive systematic study of the group.

First Evidence of Glyphosate in American Horseshoe Crab from the Yucatan Peninsula in Mexico.

Glyphosate is the most used herbicide in the world. Unfortunately, contamination of water bodies by this herbicide has been reported. A severe concern has been triggered given its detrimental impact on the environment and wildlife. The American horseshoe crab (Limulus polyphemus) is a benthic arthropod that inhabits the Yucatan Peninsula in Southeast Mexico. This study evaluates the glyphosate concentration in 34 recently dead specimens of L. polyphemus from four localities of the Ria Lagartos Biosphere Reserve in Yucatan, Mexico. The analysis was carried out using High-Performance Liquid Chromatography coupled with a Triple Quadrupole Mass Spectrometer. All the samples showed residues of glyphosate in the range from 0.08 to 2.38 ng g-1. These records constitute the first evidence of glyphosate bioaccumulation in this species. Although the scope might be limited, the results demonstrate a potentially prejudicial exposition of the marine biota to glyphosate-based herbicides, given its use in the region.

Comparing Sediment Microbiomes in Contaminated and Pristine Wetlands along the Coast of Yucatan.

Microbial communities are important players in coastal sediments for the functioning of the ecosystem and the regulation of biogeochemical cycles. They also have great potential as indicators of environmental perturbations. To assess how microbial communities can change their composition and abundance along coastal areas, we analyzed the composition of the microbiome of four locations of the Yucatan Peninsula using 16S rRNA gene amplicon sequencing. To this end, sediment from two conserved (El Palmar and Bocas de Dzilam) and two contaminated locations (Sisal and Progreso) from the coast northwest of the Yucatan Peninsula in three different years, 2017, 2018 and 2019, were sampled and sequenced. Microbial communities were found to be significantly different between the locations. The most noticeable difference was the greater relative abundance of Planctomycetes present at the conserved locations, versus FBP group found with greater abundance in contaminated locations. In addition to the difference in taxonomic groups composition, there is a variation in evenness, which results in the samples of Bocas de Dzilam and Progreso being grouped separately from those obtained in El Palmar and Sisal. We also carry out the functional prediction of the metabolic capacities of the microbial communities analyzed, identifying differences in their functional profiles. Our results indicate that landscape of the coastal microbiome of Yucatan sediment shows changes along the coastline, reflecting the constant dynamics of coastal environments and their impact on microbial diversity.

Cytotoxic activity against breast cancer cells of two species of marine sponges from shallows of Yucatan peninsula.

This study aimed to evaluate the in vitro activity of extracts of two marine sponge species, occurring in the shallows of the Yucatan peninsula coast, on two cancer and one normal mammalian cell lines. Hexane, dichloromethane, ethyl acetate and methanol extracts of Halichondria magniconulosa and Halichondria melanadocia were screened for their cytotoxic activity against hormone-dependent breast cancer (MCF-7) and human cervix cancer (SiHa) cell lines. The ethyl acetate extract of H. magniconulosa exhibited significant cytotoxicity against MCF-7 cells to a CC50 of 0.8 µg/mL, as well as high selectivity (SI = 24.5). On the other hand, SiHa cells were moderately sensitive to the dichloromethane and ethyl acetate extracts of the same species. (CC50 = 34.9 and 31.5 µg/mL, respectively). None of the extracts of H. melanadocia were considered active due their CC50's were ranged from 59.0 to 94.5 µg/mL.

First record of larval microhabitats of sandflies in Mexico with the description of the fourth instar larva of Brumptomyia hamata.

Despite the medical importance of sandflies as vectors (Diptera: Phlebotominae) of Leishmania spp., immature stages of phlebotomine sandflies have never been found in the wild in Mexico. In the present investigation, we sought to identify specific microhabitats associated with the presence of sandfly immature stages. Field work was conducted in 11 localities of the Yucatan Peninsula and we collected soil samples from each site during two periods (November 2007 to April 2008, November 2008). Soil samples were transported to our base camp and were processed using the Berlese's funnels. We processed a total 242 soil samples with an average weight of 362 ± (SD) 317 gr. From these samples, we were able to recover 51 phlebotomine larvae in five different microhabitats and largest number was obtained from mammal burrows (88%) and from tree-buttresses of Brosimium alicastrum (Berg) (6%). We identified larval microhabitat for Brumptomyia hamata (Fairchild & Hertig) and those specimens provided the material to describe for the first time the fourth instar larva. We also include information of a larval microhabitat of Lutzomyia cruciata (Coquillett). In addition, we recorded a total of 4872 arthropods from 15 taxa in all those soil samples in which sandfly larvae were found, being Collembola (76%) and Acari (10%) the most abundant.

Cuba in Mexico: first record of Phyllops falcatus (Gray, 1839) (Chiroptera, Phyllostomidae) for Mexico and other new records of bats from Cozumel, Quintana Roo.

The first record of Phyllops falcatus (Gray, 1839) in Mexico is documented from the island of Cozumel, Quintana Roo. This species is present in the Antilles, distributed in all the Cuban archipelago, Cayman Islands, and Hispaniola. It is likely that a hurricane moved these bats from Cuba to Cozumel. The Cozumel record extends the distribution more than 200 km west. Two new records from Cozumel of the bats Lasiurus ega and Molossus alvarezi are also provided.

Improving aboveground biomass maps of tropical dry forests by integrating LiDAR, ALOS PALSAR, climate and field data.

BACKGROUND: Reliable information about the spatial distribution of aboveground biomass (AGB) in tropical forests is fundamental for climate change mitigation and for maintaining carbon stocks. Recent AGB maps at continental and national scales have shown large uncertainties, particularly in tropical areas with high AGB values. Errors in AGB maps are linked to the quality of plot data used to calibrate remote sensing products, and the ability of radar data to map high AGB forest. Here we suggest an approach to improve the accuracy of AGB maps and test this approach with a case study of the tropical forests of the Yucatan peninsula, where the accuracy of AGB mapping is lower than other forest types in Mexico. To reduce the errors in field data, National Forest Inventory (NFI) plots were corrected to consider small trees. Temporal differences between NFI plots and imagery acquisition were addressed by considering biomass changes over time. To overcome issues related to saturation of radar backscatter, we incorporate radar texture metrics and climate data to improve the accuracy of AGB maps. Finally, we increased the number of sampling plots using biomass estimates derived from LiDAR data to assess if increasing sample size could improve the accuracy of AGB estimates. RESULTS: Correcting NFI plot data for both small trees and temporal differences between field and remotely sensed measurements reduced the relative error of biomass estimates by 12.2%. Using a machine learning algorithm, Random Forest, with corrected field plot data, backscatter and surface texture from the L-band synthetic aperture radar (PALSAR) installed on the on the Advanced Land Observing Satellite-1 (ALOS), and climatic water deficit data improved the accuracy of the maps obtained in this study as compared to previous studies (R2 = 0.44 vs R2 = 0.32). However, using sample plots derived from LiDAR data to increase sample size did not improve accuracy of AGB maps (R2 = 0.26). CONCLUSIONS: This study reveals that the suggested approach has the potential to improve AGB maps of tropical dry forests and shows predictors of AGB that should be considered in future studies. Our results highlight the importance of using ecological knowledge to correct errors associated with both the plot-level biomass estimates and the mismatch between field and remotely sensed data.