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Subcutaneous emphysema is the novo infiltration of air in the subcutaneous layer of skin. The incidence of subcutaneous emphysema varies from 0.43% to 2.34%. and can result from surgical, traumatic, infectious, or idiopathic processes. Air can enter the subcutaneous tissue through occupational accidents, as occurred in our clinical presentation; on physical examination, the most common finding associated with subcutaneous emphysema is crepitus on palpation. It is important to make a timely diagnosis to determine the cause, provide appropriate management and avoid complications.

El análisis de los diferentes rasgos que caracterizan un paisaje, constituye un requisito esencial para conocer la evolución geomorfológica, repercutiendo en gran medida en el desarrollo productivo de una región, conociendo los aspectos positivos y negativos que pueden afectarlos o potenciarlos. Para ello, es necesario reconocer, caracterizar y clasificar las morfologías presentes, que dan cuenta de los factores y procesos que actuaron en su formación, y contribuyen en la interpretación y reconstrucción de la evolución del relieve a diversas escalas. La cuenca del río Amarillo se encuentra en la Sierra de Famatina, la cual está ubicada en el centro-norte de la provincia de La Rioja, en el noroeste de la Argentina. Se llevaron a cabo tareas de gabinete y de campo con el fin de analizar, reconocer e identificar los principales rasgos geomorfológicos presentes, y establecer su disposición espacial. En los sectores más elevados de la cuenca se destacan geoformas asociadas a procesos glaciales, periglaciales y gravitacionales, propiciados por las bajas temperaturas, fuertes pendientes y falta de vegetación. Las formas fluviales, tanto de acumulación como de erosión, fueron identificados en toda el área analizada, mientras que se describen depósitos lacustres en donde se interpreta que su formación estuvo asociado al evento árido a nivel global definido como Meghalayan Stage. Esta distribución y tipología de geoformas, condicionadas por la tectónica y los procesos exógenos, propiciaron una compleja evolución geomorfológica en el Cuaternario de la cuenca del río Amarillo.

Proteins like NADH:ubiquinone oxidoreductase (NQR), an essential enzyme and ion pump in the physiology of several pathogenic bacteria, tightly regulate the redox properties of their cofactors. Although flavin mononucleotide (FMN) is fully reduced in aqueous solution, FMN in subunits B and C of NQR exclusively undergo one-electron transitions during its catalytic cycle. Here, we perform ab initio calculations and molecular dynamics simulations to elucidate the mechanisms that regulate the redox state of FMN in NQR. QM/MM calculations show that binding site electrostatics disfavor anionic forms of FMNH(2), but permit a neutral form of the fully reduced flavin. The potential energy surface is unaffected by covalent bonding between FMN and threonine. Molecular dynamics simulations show that the FMN binding sites are inaccessible by water, suggesting that further reductions of the cofactors are limited or prohibited by the availability of water and other proton donors. These findings provide a deeper understanding of the mechanisms used by NQR to regulate electron transfer through the cofactors and perform its physiologic role. They also provide the first, to our knowledge, evidence of the simple concept that proteins regulate flavin redox states via water occlusion.

The present work tries to expose the diverse conflicts for the use of the space and the marine resources in the Marine Area of ??Responsible Fishing of Paquera and Tambor, in the area of ??the Gulf of Nicoya in the Central Pacific of Costa Rica. This marine area is a marine spatial planning strategy that is managed as of 2014, as a proposal for territorial governance. To understand the dynamics of territorial governance and its relationship with social, economic and environmental development, one must first identify the various conflicts between the actors with some type of territorial registration; as well as the global dynamics of the market that support the construction of a concrete vision and action on the fishing resource and the competition for extraction spaces. Regarding territorial governance in the Paquera-Tambor marine responsible fishing area (AMPR), it should be pointed out that, despite being spaces where local actors play an important role, the institutions try to co-opt the processes. What this cooptation generates are conflicts that materialize in the struggle between fishermen for their fishing or conservation areas, the institutional capacity not having the resolution or minimization of the conflict. El presente trabajo pretende exponer los diversos conflictos por el uso del espacio y los recursos marinos en el Área Marina de Pesca Responsable de Paquera y Tambor, en la zona del Golfo de Nicoya en el Pacífico Central de Costa Rica. Esta área marina es una estrategia de ordenamiento espacial marino que se gestiona a partir del año 2014, como una propuesta de gobernanza territorial. Para entender las dinámicas de gobernanza territorial y su relación con el desarrollo social, económico y ambiental se debe primeramente identificar las diversas conflictividades entre los actores con algún tipo de inscripción territorial; así como, las dinámicas globales del mercado que apoyan la construcción de una visión y acción concreta sobre el recurso pesquero y la competencia por los espacios de extracción. Respecto la gobernanza territorial en el área marina de pesca responsable (AMPR) Paquera- Tambor, debe indicarse que, a pesar de ser espacios donde los actores locales cumplen un papel importante, la institucionalidad trata de cooptar los procesos. Esta cooptación lo que genera son conflictos que se materializan en la lucha entre pescadores por sus espacios de pesca o de conservación, no teniendo la institucionalidad capacidad para la resolución ni minimización del conflicto.

The ion-pumping NQR complex is an essential respiratory enzyme in the physiology of many pathogenic bacteria. This enzyme transfers electrons from NADH to ubiquinone through several cofactors, including riboflavin (vitamin B2). NQR is the only enzyme reported that is able to use riboflavin as a cofactor. Moreover, the riboflavin molecule is found as a stable neutral semiquinone radical. The otherwise highly reactive unpaired electron is stabilized via an unknown mechanism. Crystallographic data suggested that riboflavin might be found in a superficially located site in the interface of NQR subunits B and E. However, this location is highly problematic, as the site does not have the expected physiochemical properties. In this work, we have located the riboflavin-binding site in an amphipathic pocket in subunit B, previously proposed to be the entry site of sodium. Here, we show that this site contains absolutely conserved residues, including N200, N203, and D346. Mutations of these residues decrease enzymatic activity and specifically block the ability of NQR to bind riboflavin. Docking analysis and molecular dynamics simulations indicate that these residues participate directly in riboflavin binding, establishing hydrogen bonds that stabilize the cofactor in the site. We conclude that riboflavin is likely bound in the proposed pocket, which is consistent with enzymatic characterizations, thermodynamic studies, and distance between cofactors.

The ion-pumping NADH: ubiquinone dehydrogenase (NQR) is a vital component of the respiratory chain of numerous species of marine and pathogenic bacteria, including Vibrio cholerae. This respiratory enzyme couples the transfer of electrons from NADH to ubiquinone (UQ) to the pumping of ions across the plasma membrane, producing a gradient that sustains multiple homeostatic processes. The binding site of UQ within the enzyme is an important functional and structural motif that could be used to design drugs against pathogenic bacteria. Our group recently located the UQ site in the interface between subunits B and D and identified the residues within subunit B that are important for UQ binding. In this study, we carried out alanine scanning mutagenesis of amino acid residues located in subunit D of V. cholerae NQR to understand their role in UQ binding and enzymatic catalysis. Moreover, molecular docking calculations were performed to characterize the structure of the site at the atomic level. The results show that mutations in these positions, in particular, in residues P185, L190, and F193, decrease the turnover rate and increase the Km for UQ. These mutants also showed an increase in the resistance against the inhibitor HQNO. The data indicate that residues in subunit D fulfill important structural roles, restricting and orienting UQ in a catalytically favorable position. In addition, mutations of these residues open the site and allow the simultaneous binding of substrate and inhibitors, producing partial inhibition, which appears to be a strategy used by Pseudomonas aeruginosa to avoid autopoisoning.

The flavin transferase ApbE plays essential roles in bacterial physiology, covalently incorporating FMN cofactors into numerous respiratory enzymes that use the integrated cofactors as electron carriers. In this work we performed a detailed kinetic and structural characterization of Vibrio cholerae WT ApbE and mutants of the conserved residue His-257, to understand its role in substrate binding and in the catalytic mechanism of this family. Bi-substrate kinetic experiments revealed that ApbE follows a random Bi Bi sequential kinetic mechanism, in which a ternary complex is formed, indicating that both substrates must be bound to the enzyme for the reaction to proceed. Steady-state kinetic analyses show that the turnover rates of His-257 mutants are significantly smaller than those of WT ApbE, and have increased Km values for both substrates, indicating that the His-257 residue plays important roles in catalysis and in enzyme-substrate complex formation. Analyses of the pH dependence of ApbE activity indicate that the pKa of the catalytic residue (pKES1) increases by 2 pH units in the His-257 mutants, suggesting that this residue plays a role in substrate deprotonation. The crystal structures of WT ApbE and an H257G mutant were determined at 1.61 and 1.92 A resolutions, revealing that His-257 is located in the catalytic site and that the substitution does not produce major conformational changes. We propose a reaction mechanism in which His-257 acts as a general base that deprotonates the acceptor residue, which subsequently performs a nucleophilic attack on FAD for flavin transfer.

Observations of wild male O. maya suggest that temperatures below 27 °C favour their reproductive performance. From these observations we hypothesize that, as in females, the temperature modulates the reproductive performance of adult O. maya males. The study aimed to evaluate the physiological condition, reproductive success, and histological damage in testis of male O. maya exposed to thermal stress, to determine the implications of ocean warming over their reproductive performance. High temperatures (28–30 °C) negatively affect the growth and health of male O. maya. In octopuses maintained at 30 °C, as a consequence of the thermal stress we observed an increment in the haemocytes number, a reduction in the oxygen consumption rate, and an inflammatory process in the testis. The number of spermatozoa per spermatophore was not affected by temperature, but higher spermatophores production was observed at 30 °C. The paternity analysis showed that the offspring had multiple paternity with an average of 10 males contributing in a single spawn. The paternal contribution was affected by temperature with high, medium, or no paternal contribution in animals maintained at 24 °C (control group), 28 °C and 30 °C, respectively. The temperatures from 28 °C to 30 °C deeply affected the reproductive performance of Octopus maya males, suggesting that, as embryos, reproductive performance of adult males of this octopus species can be used as a tool for monitoring thermal changes in Yucatan Peninsula, located at the entrance of Gulf of Mexico.

The Cortes geoduck Panopea globosa is a large bivalve with a high commercial value distributed from the southern Pacific coast of the Baja California Peninsula to the northern Gulf of California, inhabiting a wide range of subtropical temperatures. A new record of this species in shallower waters suggests that it can tolerate a warmer environment than previously thought. To better understand the whole-body and molecular response mechanisms to different temperatures, we assessed the metabolic rate of juvenile individuals exposed to chronic and acute thermal conditions and analyzed the transcriptomic response in ctenidial tissues. Whole-body metabolic rate measurements showed that juveniles were able to acclimate at least partially within three weeks from 20 °C (C20) to 29 °C (C29), while organisms acutely exposed to 29 °C (A29) significantly increased their metabolic rate. This was coincident with transcriptomic results, as similar gene expression patterns were found in clams chronically exposed to C29 and C20, but different from those acutely exposed to 29 °C (A29) and 31 °C (A31). High degree of expression of genes involved in DNA repair and transcription regulation were found in C29 juveniles, whereas protective genes against oxidative stress were highly expressed in A29 organisms. A high expression of genes involved in protein re-folding was also observed in A31 juveniles. In conclusion, the combined results of whole-body metabolism and transcriptomic expression patterns suggest that P. globosa juveniles have a high physiological plasticity and are well adapted to inhabit an environment with broad temperature fluctuations.

Seriola lalandi is an important species for aquaculture, due to its rapid growth, adaptation to captivity and formulated diets, and high commercial value. Due to the rise in fishmeal (FM) price, efforts have been and still are made to replace it partially or entirely with vegetable meals in diets for carnivorous fish. The use of prebiotics when feeding vegetable meals has improved fish health. Four experimental diets were assessed in juveniles, the control diet consisted of FM as the main protein source, the second diet included 2% of GroBiotic®-A (FM-P), in the third diet FM was partially replaced (25%) by soybean meal (SM25), and the fourth consisted of SM25 with 2% of GroBiotic®-A (SM25-P). Growth was evaluated and RNA-seq of the liver tissue was performed, including differential expression analysis and functional annotation to identify genes affected by the diets. Growth was not affected by this level of FM replacement, but it was improved by prebiotics. Annotation was achieved for 59,027 transcripts. Gene expression was affected by the factors: 225 transcripts due to FM replacement, 242 due to prebiotics inclusion, and 62 due to the interaction of factors. The SM25-P diet showed the least amount of differentially expressed genes against the control diet. The replacement of FM (25%) by soybean meal combined with prebiotics (2%) represents a good cost-benefit balance for S. lalandi juveniles since the fish growth increased and important metabolic and immune system genes in the liver were upregulated with this diet.

Salmonella enterica subspecies I (ssp 1) is the leading cause of hospitalizations and deaths due to known bacterial foodborne pathogens in the United States and is frequently implicated in foodborne disease outbreaks associated with spices and nuts. However, the underlying mechanisms of this association have not been fully elucidated. In this study, we evaluated the influence of storage temperature (4 or 25°C), relative humidity (20 or 60%), and food surface characteristics on the attachment and survival of five individual strains representing S. enterica ssp 1 serovars Typhimurium, Montevideo, Braenderup, Mbandaka, and Enteritidis on raw in-shell black peppercorns, almonds, and hazelnuts. We observed a direct correlation between the food surface roughness and S. enterica ssp 1 attachment, and detected significant inter-strain difference in survival on the shell surface under various storage conditions. A combination of low relative humidity (20%) and ambient storage temperature (25°C) resulted in the most significant reduction of S. enterica on shell surfaces (p < 0.05). To identify genes potentially associated with S. enterica attachment and survival on shell surfaces, we inoculated a library of 120,000 random transposon insertion mutants of an S. Enteritidis strain on almond shells, and screened for mutant survival after 1, 3, 7, and 14 days of storage at 20% relative humidity and 25°C. Mutants in 155 S. Enteritidis genes which are involved in carbohydrate metabolic pathways, aerobic and anaerobic respiration, inner membrane transport, and glutamine synthesis displayed significant selection on almond shells (p < 0.05). Findings of this study suggest that various food attributes, environmental factors, and an unexpectedly complex metabolic and regulatory network in S. enterica ssp 1 collectively contribute to the bacterial attachment and survival on low moisture shell surface, providing new data for the future development of knowledge-based intervention strategies.

A short, efficient one-step synthesis of 2-methyl-5-(3-methyl-2-butenyl)-1,4-benzoquinone, a natural product from Pyrola media is described. The synthesis is based on a direct late C-H functionalization of the quinone scaffold. The formation of the natural product was confirmed by means of 2D-NMR spectroscopy. Additional derivatives were synthesized and tested alongside the natural product as potential substrate and substrate-based inhibitors of mitochondrial complex I (MCI). The structure-activity relationship study led to the discovery of 3-methylbuteneoxide-1,4-anthraquinone (1 i), an inhibitor with an IC50 of 5 μM against MCI. The identified molecule showed high selectivity for MCI when tested against other quinone-converting enzymes, including succinate dehydrogenase, and the Na (+)-translocating NADH:quinone oxidoreductase. Moreover, the identified inhibitor was also active in cell-based proliferation assays. Therefore, 1 i can be considered as a novel chemical probe for MCI.

Pseudomonas aeruginosa is a Gram-negative bacterium responsible for a large number of nosocomial infections. The P. aeruginosa respiratory chain contains the ion-pumping NADH:ubiquinone oxidoreductase (NQR). This enzyme couples the transfer of electrons from NADH to ubiquinone to the pumping of sodium ions across the cell membrane, generating a gradient that drives essential cellular processes in many bacteria. In this study, we characterized P. aeruginosa NQR (Pa-NQR) to elucidate its physiologic function. Our analyses reveal that Pa-NQR, in contrast with NQR homologues from other bacterial species, is not a sodium pump, but rather a completely new form of proton pump. Homology modeling and molecular dynamics simulations suggest that cation selectivity could be determined by the exit ion channels. We also show that Pa-NQR is resistant to the inhibitor 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO). HQNO is a quinolone secreted by P. aeruginosa during infection that acts as a quorum sensing agent and also has bactericidal properties against other bacteria. Using comparative analysis and computational modeling of the ubiquinone-binding site, we identified the specific residues that confer resistance toward this inhibitor. In summary, our findings indicate that Pa-NQR is a proton pump rather than a sodium pump and is highly resistant against the P. aeruginosa–produced compound HQNO, suggesting an important role in the adaptation against autotoxicity. These results provide a deep understanding of the metabolic role of NQR in P. aeruginosa and provide insight into the structural factors that determine the functional specialization in this family of respiratory complexes.

The Octopus maya fishery is one of the most important among the octopod fisheries in America. Recent studies about the wild population of this species, have contributed to understand that population variations and dynamics are highly influenced by temperature. The distribution area of this species could be divided in two well-differentiated thermal zones: an eastern zone influenced by the upwelling pulses, and a western zone with no upwelling influence. There is evidence suggesting that variations in population parameters could be linked to these thermal zones. However the fishery is still managed as one single unit, and there is no control of the capture limit. In this study we analyzed the multilocus microsatellite genotypes of wild O. maya across its distribution area to find out if the population is structured, and if the structure matches the mentioned thermal zones. Additionally, the heterozygosity was compared between samples from 2010 and 2015 to monitor changes related to the high fishing pressure. Results show that O. maya population is structured in two clusters that match with the different thermal zones in the distribution area. Moreover, significant genic differentiation was detected between these thermal zones. On the other hand, despite the high fishing pressure over this species, there is no significant difference in heterozygosity between 2010 and 2015 samples, and no inbreeding was detected, showing that genetic diversity is still high. We recommend the continuous monitoring of heterozygosity in this species, and a separate fishery management for Campeche (western) and Yucatan (eastern) subpopulations.

The Sierra de Famatina is considered the highest elevation outside the Argentine Andes Cordillera, being the General Belgrano hill, 6097 masl, the main height. This altitudinal situation favored the development of glaciers during the cold events of the cyclical Quaternary climatic fluctuations, giving shape to a territory with very complex morphologies. The aim of this contribution is to describe the current and past geomorphological processes in the vicinity of the highest sector of the Sierra de Famatina through different forms of the landscape, which put together allow the recognition of the geomorphological evolution of the region. At present, extreme weather lead to periglacial conditions above 4000 m and glacial above 6000 m, generating ice and snow patches almost without movements in flat to flat-concave sections of the watersheds, and rock glaciers, gelifluction lobes and earth hummocks in cirques, troughs and walls of valleys. Depending on the features of glacial accumulation, three cold events can be recognized, the youngest one (MIS2) with limited distribution, is restricted to the heads of troughs and cirques, from whose deposits the rock glaciers develop. The second one, observed near Puesto Tres Piedras, is represented by moraine-shaped glacier deposits above 3000 m height, and would belong to the Middle-Late Pleistocene. The oldest glacier deposits, early-middle Pleistocene, are in higher topographies. Below 3000 m, valleys are rocky and steep-sided, with permanent courses due not only to low rainfall, but mainly to the melting of the permafrost, forming important reservoirs of water. Fil: Fucks, Enrique Eduardo. Universidad Nacional de Chilecito; Argentina. Universidad Nacional de La Plata; Argentina Fil: Corbat, María Cecilia. Universidad Nacional de La Plata; Argentina. Universidad Nacional de Chilecito; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Juárez, Oscar. Universidad Nacional de Chilecito; Argentina

Thorium is a well-known radioactive and chemically toxic contaminant in the environment. The continuous exposure to thorium may cause an increased risk of developing lung and liver diseases as well as lung, pancreas and bone cancer. Due to its use in nuclear industry and other industrial applications, thorium may be accidentally released to the environment from its mining and processing plants. In this work, we developed a rapid, real-time, and label-free nanopore sensor for Th(4+) detection by using an aspartic acid containing peptide as a chelating agent and tuning the electrolyte solution pH to control the net charges of the peptide ligand and its metal ion complex. The method is highly sensitive with a detection limit of 0.45 nanomolar. Furthermore, the sensor is selective: other metal ions (e.g., UO(2)(2+), Pb(2+), Cu(2+), Ni(2+), Hg(2+), Zn(2+), As(3+), Mg(2+), and Ca(2+)) with concentrations of up to three orders of magnitude greater than that of Th(4+) would not interfere with Th(4+)detection. In addition, simulated water samples were successfully analyzed. Our developed computation-assisted sensing strategy should find useful applications in the development of nanopore sensors for other metal ions.

Chlamydia trachomatis is an obligate intracellular human pathogen responsible for the most prevalent sexually-transmitted infection in the world. For decades C. trachomatis has been considered an "energy parasite" that relies entirely on the uptake of ATP from the host cell. The genomic data suggest that C. trachomatis respiratory chain could produce a sodium gradient that may sustain the energetic demands required for its rapid multiplication. However, this mechanism awaits experimental confirmation. Moreover, the relationship of chlamydiae with the host cell, in particular its energy dependence, is not well understood. In this work, we are showing that C. trachomatis has an active respiratory metabolism that seems to be coupled to the sodium-dependent synthesis of ATP. Moreover, our results show that the inhibition of mitochondrial ATP synthesis at an early stage decreases the rate of infection and the chlamydial inclusion size. In contrast, the inhibition of the chlamydial respiratory chain at mid-stage of the infection cycle decreases the inclusion size but has no effect on infection rate. Remarkably, the addition of monensin, a Na+/H+ exchanger, completely halts the infection. Altogether, our data indicate that chlamydial development has a dynamic relationship with the mitochondrial metabolism of the host, in which the bacterium mostly depends on host ATP synthesis at an early stage, and at later stages it can sustain its own energy needs through the formation of a sodium gradient.

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The Pacific oyster Crassostrea gigas is the most cultivated oyster species around the world. However, massive mortalities linked to high temperatures have been reported in different countries, becoming one of the most significant challenges for oyster culture. High mortality episodes have been reported also in Mexico due to temperature stress, mainly in Sonora and Baja California Sur. In this region, areas with shallow waters can reach 34 °C, causing severe physiological stress, mostly in juvenile oysters. Recently and as a strategy to address this problem in Mexico, a selective breeding program has been implemented, aiming to develop families with high survival at high temperatures through marker-aided selection. The objective of the present study was the identification of SNP markers from the transcriptome of families phenotypically different: thermo-resistant (‘R’) versus thermo-susceptible (‘S’) and analyzing whether these variants were present in transcripts potentially involved in thermal resistance. Several SNP variants were detected between ‘R’ and ‘S’ families, affecting multiple transcripts and molecular pathways. Four SNP markers provided accurate differentiation between ‘R’ and ‘S’ oysters. Additionally, 66 SNPs were suitable for pedigree reconstruction and sibling clustering. The discriminant SNPs were associated with changes in gene transcripts that were related to biological processes such as the activation of HSP90, zinc uptake, collagen biosynthesis, ion transport, and the immune response. The use of SNPs markers associated with thermo-resistant families can help to improve the yields in oyster production at high temperatures, especially in Mexico.

The sodium-dependent NADH dehydrogenase (Na+-NQR) is a key component of the respiratory chain of diverse prokaryotic species, including pathogenic bacteria. Na+-NQR uses the energy released by electron transfer between NADH and ubiquinone (UQ) to pump sodium, producing a gradient that sustains many essential homeostatic processes as well as virulence factor secretion and the elimination of drugs. The location of the UQ binding site has been controversial, with two main hypotheses that suggest that this site could be located in the cytosolic subunit A or in the membrane-bound subunit B. In this work, we performed alanine scanning mutagenesis of aromatic residues located in transmembrane helices II, IV, and V of subunit B, near glycine residues 140 and 141. These two critical glycine residues form part of the structures that regulate the site's accessibility. Our results indicate that the elimination of phenylalanine residue 211 or 213 abolishes the UQ-dependent activity, produces a leak of electrons to oxygen, and completely blocks the binding of UQ and the inhibitor HQNO. Molecular docking calculations predict that UQ interacts with phenylalanine 211 and pinpoints the location of the binding site in the interface of subunits B and D. The mutagenesis and structural analysis allow us to propose a novel UQ-binding motif, which is completely different compared with the sites of other respiratory photosynthetic complexes. These results are essential to understanding the electron transfer pathways and mechanism of Na+-NQR catalysis.

Most of our understanding on embryonic development in cephalopods comes from studies using constant temperature. Even though spawning generally occurs at relatively stable environments, eggs and embryos can be exposed over short periods of time to high temperature anomalies caused by oceanic warming. Therefore, in this study we examined the effects of increasing temperatures on growth, respiratory metabolism, and antioxidant defense mechanisms to define the thermal limits of Octopus maya embryos in a changing environment. Ramp temperatures consisted in increments of 1 °C every 5 days from 24 °C to 30 °C. The thermal limit of embryos at ramp temperatures was detected at 27 °C with metabolic rate increments between 63% and 69%, compared with the metabolic rate observed at control temperature (24 °C). Based on the calculated integrated biomarker response (IBR) was possible to detect that at the thermal limit, an increment on oxygen consumption was observed joint with reactive oxygen species (ROS). The IBR analysis indicated that above 27 °C embryos experienced changes in the oxidative system and were not able to recover. This study suggests that in a scenario of rapidly increasing temperatures after a short winter, O. maya embryos may suffer irreversible effects that are likely to negatively affect recruitment and the population dynamic. The thermal sensitivity of O. maya embryos, revealed in the present work, indicates that this species has an important potential for biomonitoring of the effects of environmental warming. Changes in the population dynamics of this species should be further studied since they can be used as a proxy for warming of the southern Gulf of Mexico ecosystems.

El documento analiza la afectación del recurso pesquero y los ecosistemas marinos como parte de un conflicto social, de carácter estructural, cuyo detonante son las relaciones sociales de producción de nuestra sociedad. Nuestro interés es aportar al análisis de la situación conflictiva a nivel socio- ambiental que vive el Golfo de Nicoya desde hace dos décadas, sobre todo en la parte relacionada con las formas que adquiere el conflicto desde el punto de vista institucional, cultural y económico. Poder entender esa situación, posibilita comprender cómo pescadores, otrora “artesanales”, han copiado las prácticas destructivas e insostenibles de pesquerías industriales, dejando de ser “artesanales”: el uso de trasmallos “ilegales”, uso de redes de arrastre de camarón, el uso de la técnica del rodeo, entre otros. The document analyzes the affectation of the fishing resource and marine ecosystems as part of a social conflict, of a structural nature, whose trigger is the social relations of production of our society. Our interest is to contribute to the analysis of the conflict situation at the socioenvironmental level that the Gulf of Nicoya has been experiencing for two decades, especially in the part related to the forms acquired by the conflict from the institutional, cultural and economic point of view. Being able to understand that situation makes it possible to understand how fishermen, once “artisanal”, have copied the destructive and unsustainable practices of industrial fisheries, ceasing to be “artisanal”: the use of “illegal” trasmallos, use of shrimp trawls, the use of the rodeo technique, among others. O documento analisa a afetação dos recursos pesqueiros e dos ecossistemas marinhos como parte de um conflito social, de natureza estrutural, cujo gatilho são as relações sociais de produção de nossa sociedade. Nosso interesse é contribuir para a análise da situação de conflito no nível socioambiental que o Golfo de Nicoya enfrenta há duas décadas, principalmente na parte relacionada às formas adquiridas pelo conflito do ponto de vista institucional, cultural e econômico. De vista. Conseguir entender essa situação torna possível entender como os pescadores, uma vez “artesanais”, copiaram as práticas destrutivas e insustentáveis da pesca industrial, deixando de ser “artesanais”: o uso de trasmallos “ilegais”, o uso de redes de arrasto de camarão, o uso da técnica de rodeio, entre outros. Universidad Nacional, Costa Rica Escuela de Planificación y Promoción Social

The sodium-pumping NADH:quinone oxidoreductase (Na+-NQR) is a bacterial enzyme that oxidizes NADH, reduces ubiquinone, and translocates Na+ across the membrane. We previously identified three acidic residues in the membrane-spanning helices, near the cytosol, NqrB-D397, NqrD-D133, and NqrE-E95, as candidates likely to be involved in Na+ uptake, and replacement of any one of them by a non-acidic residue affects the Na+-dependent kinetics of the enzyme. Here, we have inquired further into the role of the NqrE-E95 residue by constructing a series of mutants in which this residue is replaced by amino acids with charges and/or sizes different from those of the glutamate of the wild-type enzyme. All of the mutants showed altered steady-state kinetics with the acceleration of turnover by Na+ greatly diminished. Selected mutants were studied by other physical methods. Membrane potential measurements showed that NqrE-E95D and A are significantly less efficient in ion transport. NqrE-E95A, Q, and D were studied by ...

White bodies (WB), multilobulated soft tissue that wraps the optic tracts and optic lobes, have been considered the hematopoietic organ of the cephalopods. Its glandular appearance and its lobular morphology suggest that different parts of the WB may perform different functions, but a detailed functional analysis of the octopus WB is lacking. The aim of this study is to describe the transcriptomic profile of WB to better understand its functions, with emphasis on the difference between sexes during reproductive events. Then, validation via qPCR was performed using different tissues to find out tissue-specific transcripts. High differentiation in signaling pathways was observed in the comparison of female and male transcriptomic profiles. For instance, the expression of genes involved in the androgen receptor-signaling pathway were detected only in males, whereas estrogen receptor showed higher expression in females. Highly expressed genes in males enriched oxidation-reduction and apoptotic processes, which are related to the immune response. On the other hand, expression of genes involved in replicative senescence and the response to cortisol were only detected in females. Moreover, the transcripts with higher expression in females enriched a wide variety of signaling pathways mediated by molecules like neuropeptides, integrins, MAPKs and receptors like TNF and Toll-like. In addition, these putative neuropeptide transcripts, showed higher expression in females’ WB and were not detected in other analyzed tissues. These results suggest that the differentiation in signaling pathways in white bodies of O. maya influences the physiological dimorphism between females and males during the reproductive phase.

The analysis of the geomorphological features developed over a given area contributes to the knowledge of the processes that intervened in the evolution of the landscape, helping to reliably understand their interaction with the surface and underground water resources. The headwaters of the Rio del Oro are in the Sierra de Famatina, which is located in the north center of La Rioja Province. Based on the collection and analysis of the bibliography and images of the study area and field work, several geomorphological features of the area were identified and characterized, in order to establish links with their locations and determine the agents and processes that acted in landscape modeling. In turn, a hydrological description was made to broaden the knowledge of the water resource of this area, which is essential according to the arid climatic conditions. Despite the aforementioned context, fluvial activity stands out as one of the main relief modelers, considering the neotectonics and the Quaternary climate changes as notable factors in evolution.

Octopus maya supports an important fishery in Yucatan Peninsula (YP) where this species is highly abundant. Considering that temperatures in the tropics are increasing (IPCC, 2013), there are several scenarios that can modify the dynamic of the O. maya population in YP: i) prolonged summer and short winter seasons, and/or ii) fast temperature increases and high temperatures after a winter season, both affecting the survival of hatchlings and the performance of juveniles. The present study was designed to evaluate the effect of maternal temperature stress over hatchling and juvenile performance in terms of their energetic plasticity and thermoregulatory behaviour, when they were exposed to a gradual temperature increase (TI) from 24 to 30 °C and compared with hatchlings maintained at preferred and constant temperature (24 °C). Hatchlings from stressed females were smaller, and had a lower growth rate compared to those from unstressed females providing evidence that temperature stress experienced by females has consequences on the performance of hatchlings, with effects on the biomass production and survival. Results also demonstrated that hatchlings exposed to TI (24–30 °C) had a growth rate and oxygen consumption similar to those maintained at preferred temperature (24 °C), in both female groups indicating that a gradual temperature increase of 1 °C every 5 days is probably enough to allow the organisms to make physiological adjustments without an excessive energetic cost.

Este artículo expone la sistematización de las percepciones de los estudiantes de la carrera de Planificación Económica y Social vinculados al proyecto de extensión "Gestión comunitaria para el fortalecimiento productivo de las Áreas Marinas de Pesca Responsable del Golfo de Nicoya" de la Universidad Nacional de Costa Rica. Su objetivo fue conocer la forma en la cual la curricularización de la extensión universitaria brinda aportes en la transformación de los procesos de enseñanza y aprendizaje desde la reconstrucción crítica de las experiencias del estudiantado. Metodológicamente, se trabajó a partir del descubrimiento y la interpretación subjetiva/intersubjetiva de la realidad, lo que conllevó un abordaje dialéctico–materialista. Se utilizaron como instrumentos la entrevista conversacional y talleres participativos. A partir de la aplicación de los instrumentos se construyeron cuatro categorías analíticas, las cuales permitieron demostrar que los y las estudiantes, por medio del acompañamiento social participativo a grupos locales, tienen deconstrucciones sobre aprendizajes tradicionales y que desde su experiencia construyen nuevas formas al establecer espacios de diálogo y relaciones horizontales con las personas de las comunidades, fortaleciendo su formación profesional.

La ciencia ficción propone una realidad alterna basada en el desarrollo de la ciencia. Esta modalidad literaria, en conjunto con el teatro, puede crear mundos ilimitados para el diálogo del hombre con su entorno. Este artículo indaga en las obras “El último juicio, anticipación proletaria”, de Germán List Arzubide; “El mundo sin deseo”, de Francisco Navarro Carranza; y “Terraza infernal”, de Francisco Tario; manifestaciones mexicanas enfocadas en estas temáticas.

Pseudomonas aeruginosa is a Gram-negative γ-proteobacterium that forms part of the normal human microbiota and it is also an opportunistic pathogen, responsible for 30% of all nosocomial urinary tract infections. P. aeruginosa carries a highly branched respiratory chain that allows the colonization of many environments, such as the urinary tract, catheters and other medical devices. P. aeruginosa respiratory chain contains three different NADH dehydrogenases (complex I, NQR and NDH-2), whose physiologic roles have not been elucidated, and up to five terminal oxidases: three cytochrome c oxidases (COx), a cytochrome bo3 oxidase (CYO) and a cyanide-insensitive cytochrome bd-like oxidase (CIO). In this work, we studied the composition of the respiratory chain of P. aeruginosa cells cultured in Luria Broth (LB) and modified artificial urine media (mAUM), to understand the metabolic adaptations of this microorganism to the growth in urine. Our results show that the COx oxidases play major roles in mAUM, while P. aeruginosa relies on CYO when growing in LB medium. Moreover, our data demonstrate that the proton-pumping NQR complex is the main NADH dehydrogenase in both LB and mAUM. This enzyme is resistant to HQNO, an inhibitory molecule produced by P. aeruginosa, and may provide an advantage against the natural antibacterial agents produced by this organism. This work offers a clear picture of the composition of this pathogen’s aerobic respiratory chain and the main roles that NQR and terminal oxidases play in urine, which is essential to understand its physiology and could be used to develop new antibiotics against this notorious multidrug-resistant microorganism.

Vitreoscilla sp. strain C1 is of historical importance as the source of the first prokaryotic hemoglobin identified., Vitreoscilla sp. strain C1 is of historical importance as the source of the first prokaryotic hemoglobin identified. Vitreoscilla spp. rely on their hemoglobin and cytochrome oxidase to grow in microaerobic environments despite their aerobic nature. To help characterize this historically relevant strain, we sequenced the complete Vitreoscilla sp. strain C1 genome.