Expression, purification, and refolding of the recombinant extracellular domain ß1-subunit of the dog Na+/K+-ATPase of the epithelial cells.

The ß1-subunit of the Na+/K+-ATPase is a cell membrane protein, beyond its classic functions, it is also a cell adhesion molecule. ß1-subunits on the lateral membrane of dog kidney epithelial cells trans-interact with ß1-subunits from another neighboring cells. The ß-ß interaction is essential for the formation and stabilization of intercellular junctions. Previous studies on site-directed mutagenesis and in silico revealed that the interaction interface involves residues 198-207 and 221-229. However, it is necessary to report the interaction interface at the structural level experimentally. Here, we describe the successful cloning, overexpression in E. coli, and purification of the extracellular domain of the ß1-subunit from inclusion bodies. Experimental characterization by size exclusion chromatography and DLS indicated similar hydrodynamic properties of the protein refolded. Structural analysis by circular dichroism and Raman spectroscopy revealed the secondary structures in the folded protein of type ß-sheet, α-helix, random coil, and turn. We also performed ß1-ß1 interaction assays with the recombinant protein, showing dimers' formation (6xHisß1-ß1). Given our results, the recombinant extracellular domain of the ß1-subunit is highly similar to the native protein, therefore the current work in our laboratory aims to characterize at the atomic level the interaction interface between EDß1.

Glucose transport engineering allows mimicking fed-batch performance in batch mode and selection of superior producer strains.

BACKGROUND: Fed-batch mode is the standard culture technology for industrial bioprocesses. Nevertheless, most of the early-stage cell and process development is carried out in batch cultures, which can bias the initial selection of expression systems. Cell engineering can provide an alternative to fed-batch cultures for high-throughput screening and host selection. We have previously reported a library of Escherichia coli strains with single and multiple deletions of genes involved in glucose transport. Compared to their wild type (W3110), the mutant strains displayed lower glucose uptake, growth and aerobic acetate production rates. Therefore, when cultured in batch mode, such mutants may perform similar to W3110 cultured in fed-batch mode. To test that hypothesis, we evaluated the constitutive expression of the green fluorescence protein (GFP) in batch cultures in microbioreactors using a semi defined medium supplemented with 10 or 20 g/L glucose + 0.4 g yeast extract/g glucose. RESULTS: The mutant strains cultured in batch mode displayed a fast-growth phase (growth rate between 0.40 and 0.60 h-1) followed by a slow-growth phase (growth rate between 0.05 and 0.15 h-1), similar to typical fed-batch cultures. The phase of slow growth is most probably caused by depletion of key amino acids. Three mutants attained the highest GFP fluorescence. Particularly, a mutant named WHIC (ΔptsHIcrr, ΔmglABC), reached a GFP fluorescence up to 14-fold greater than that of W3110. Strain WHIC was cultured in 2 L bioreactors in batch mode with 100 g/L glucose + 50 g/L yeast extract. These cultures were compared with exponentially fed-batch cultures of W3110 maintaining the same slow-growth of WHIC (0.05 h-1) and using the same total amount of glucose and yeast extract than in WHIC cultures. The WHIC strain produced approx. 450 mg/L GFP, while W3110 only 220 mg/L. CONCLUSION: The combination of cell engineering and high throughput screening allowed the selection of a particular mutant that mimics fed-batch behavior in batch cultures. Moreover, the amount of GFP produced by the strain WHIC was substantially higher than that of W3110 under both, batch and fed-batch schemes. Therefore, our results represent a valuable technology for accelerated bioprocess development.

Effects of hypotension and hypertension on source memory and working memory.

OBJECTIVES: The effects of chronic low and high blood pressure on memory are unclear due to divergent results, originating in part due to participant misclassifications. The aim of this study was to compare source memory and working memory performance in individuals diagnosed with hypotension or hypertension with the performance of normotensive participants. Hypertensive and hypotensive individuals were receiving medical treatment. METHOD: From a sample of 1656 participants, 219 were identified as hypertensive, and 37 were identified as hypotensive. Each of these two groups was compared with normotensive individuals matched by age, education and sex. Source memory performance and working memory performance were assessed through computerized tasks. RESULTS: Source memory accuracy was poorer in hypotensive and hypertensive individuals than in normotensive individuals, and spatial working memory discrimination was inferior in hypertensive participants compared to normotensive individuals. CONCLUSION: Blood pressure impairment should be considered a major concern because it has been linked to severe cardiovascular and cerebrovascular diseases. Furthermore, here we show that it has negative effects on the two types of memory that are most essential for preserving a self-sufficient lifestyle.

Design of a microaerobically inducible replicon for high-yield plasmid DNA production.

A pUC-derived replicon inducible by oxygen limitation was designed and tested in fed-batch cultures of Escherichia coli. It included the addition of a second inducible copy of rnaII, the positive replication control element. The rnaII gene was expressed from Ptrc and cloned into pUC18 to test the hypothesis that the ratio of the positive control molecule RNAII to the negative control element, RNAI, was the determinant of plasmid copy number per chromosome (PCN). The construct was evaluated in several E. coli strains. Evaluations of the RNAII/RNAI ratio, PCN and plasmid yield normalized to biomass (YpDNA/X ) were performed and the initial hypothesis was probed. Furthermore, in high cell-density cultures in shake flasks, an outstanding amount of 126 mg/L of plasmid was produced. The microaerobically inducible plasmid was obtained by cloning the rnaII gene under the control of the oxygen-responsive Vitreoscilla stercoraria hemoglobin promoter. For this plasmid, but not for pUC18, the RNAII/RNAI ratio, PCN and YpDNA/X efficiently increased after the shift to the microaerobic regime in fed-batch cultures in a 1 L bioreactor. The YpDNA/X of the inducible plasmid reached 12 mg/g at the end of the fed-batch but the original pUC18 only reached ca. 6 mg/g. The proposed plasmid is a valuable alternative for the operation and scale-up of plasmid DNA production processes in which mass transfer limitations will not represent an issue.

Engineering E. coli for improved microaerobic pDNA production.

Escherichia coli strains W3110 and BL21 were engineered for the production of plasmid DNA (pDNA) under aerobic and transitions to microaerobic conditions. The gene coding for recombinase A (recA) was deleted in both strains. In addition, the Vitreoscilla hemoglobin (VHb) gene (vgb) was chromosomally inserted and constitutively expressed in each E. coli recA mutant and wild type. The recA inactivation increased the supercoiled pDNA fraction (SCF) in both strains, while VHb expression improved the pDNA production in W3110, but not in BL21. Therefore, a codon-optimized version of vgb was inserted in strain BL21recA-, which, together with W3110recA-vgb+, was tested in cultures with shifts from aerobic to oxygen-limited regimes. VHb expression lowered the accumulation of fermentative by-products in both strains. VHb-expressing cells displayed higher oxidative activity as indicated by the Redox Sensor Green fluorescence, which was more intense in BL21 than in W3110. Furthermore, VHb expression did not change pDNA production in W3110, but decreased it in BL21. These results are useful for understanding the physiological effects of VHb expression in two industrially relevant E. coli strains, and for the selection of a host for pDNA production.

Design of a synthetic miniR1 plasmid and its production by engineered Escherichia coli.

A synthetic plasmid consisting of the minimal elements for replication control of the R1 replicon and kanamycin resistance marker, which was named pminiR1, was developed. pminiR1 production was tested at 30 °C under aerobic and microaerobic conditions in Escherichia coli W3110 recA- (W1). The plasmid DNA yields from biomass (YpDNA/X) were only 0.06 ± 0.02 and 0.22 ± 0.11 mg/g under aerobic and microaerobic conditions, respectively. As an option to increase YpDNA/X values, pminiR1 was introduced in an engineered E. coli strain expressing the Vitreoscilla hemoglobin inserted in chromosome (W12). The YpDNA/X values using strain W12 increased to 0.85 ± 0.05 and 1.53 ± 0.14 mg/g under aerobic and microaerobic conditions, respectively. pminiR1 production in both strains was compared with that of pUC57Kan at 37 °C under aerobic and microaerobic conditions. The YpDNA/X values for pminiR1 using strain W12 were 6.25 ± 0.16 and 9.27 ± 0.95 mg/g under aerobic and microaerobic conditions, respectively. Such yields were similar to those obtained for plasmid pUC57Kan using strain W12 (6.9 ± 0.64 and 10.85 ± 1.06 mg/g for aerobic and microaerobic cultures, respectively). Therefore, the synthetic minimal plasmid based on the R1 replicon is a valuable alternative to pUC plasmids for biotechnological applications.

Enhanced plasmid DNA production by enzyme-controlled glucose release and an engineered Escherichia coli.

OBJECTIVES: To evaluate the combination of a culture medium employing glucoamylase-mediated glucose reléase from a gluco-polysaccharide and an E. coli strain engineered in its glucose transport system for improving plasmid DNA (pDNA) production. RESULTS: The production of pDNA was tested using E. coli DH5α grown in shake-flasks and the recently developed VH33 Δ(recA deoR)-engineered strain, which utilizes glucose more efficiently than wild type strains. Three glucoamylase concentrations for releasing glucose from the polysaccharide carbon source were used: 1, 2 and 3 U l(-1). Both strains reached similar cell densities ranging from 5 to 8.8 g l(-1) under the different conditions. The highest pDNA yields on biomass (YpDNA/X) for both strains were obtained when 3 U enzyme l(-1)were used. Under these conditions, 35 ± 3 mgof pDNA l(-1) were produced by DH5α after 24 h of culture. Under the same conditions, the engineered strain produced 66 ± 1 mgpDNAl(-1) after 20 h. pDNA supercoiled fractionswere close to 80 % for both strains. CONCLUSIONS: The pDNA concentration achieved by the engineered E. coli was 89 % higher than that of DH5α. The combination of the engineered strain and enzyme-controlled glucose release is an attractive alternative for pDNA production in shake-flasks.

Soil microarthropods and their relationship to higher trophic levels in the Pedregal de San Angel Ecological Reserve, Mexico.

Soil fauna is essential for ecosystem dynamics as it is involved in biogeochemical processes, promotes nutrient availability, and affects the animal communities associated with plants. In this study, we examine the possible relationship between the soil microarthropod community on foliage production and quality of the shrub Pittocaulon praecox. We also examine the arthropods associated to its foliage, particularly the size of the main herbivores and of their natural enemies, at two sites with contrasting vegetation cover and productivity. The diversity of soil microarthropods was assessed from soil samples collected monthly under P. praecox individuals over 13 mo. Specimens collected were identified to species or morphospecies. Shrub foliage productivity was evaluated through the amount of litter produced. Resource quality was assessed by the mean content (percentage by weight) of N, C, S, and P of 30 leaves from each shrub. The mean size of herbivores and their natural enemies were determined by measuring 20 adult specimens of each of the most abundant species. We found a higher species richness of soil microarthropods and foliar arthropods in the open site, although the diversity of foliage arthropods was lower in the closed site. Shrubs growing in the closed site tend to produce more, larger, and nutritionally poorer (lower nitrogen content) leaves than open site. Herbivores and their natural enemies were also larger in the closed site. We found a significant positive relationship between the diversity and species richness of foliar arthropods and the nitrogen content of leaves. In general, species richness and diversity of both the foliar and soil fauna, as well as the size of organisms belonging to higher trophic levels, were affected by vegetation cover and primary productivity at each site. These findings highlight the need to simultaneously consider at least four trophic levels (soil organisms, plants, herbivores, and natural enemies) to better understand the functioning of these systems and their responses to environmental changes.

Combination of Recombinant Proteins S1/N and RBD/N as Potential Vaccine Candidates.

Despite all successful efforts to develop a COVID-19 vaccine, the need to evaluate alternative antigens to produce next-generation vaccines is imperative to target emerging variants. Thus, the second generation of COVID-19 vaccines employ more than one antigen from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to induce an effective and lasting immune response. Here, we analyzed the combination of two SARS-CoV-2 viral antigens that could elicit a more durable immune response in both T- and B-cells. The nucleocapsid (N) protein, Spike protein S1 domain, and receptor binding domain (RBD) of the SARS-CoV-2 spike surface glycoproteins were expressed and purified in a mammalian expression system, taking into consideration the posttranscriptional modifications and structural characteristics. The immunogenicity of these combined proteins was evaluated in a murine model. Immunization combining S1 or RBD with the N protein induced higher levels of IgG antibodies, increased the percentage of neutralization, and elevated the production of cytokines TNF-α, IFN-γ, and IL-2 compared to the administration of a single antigen. Furthermore, sera from immunized mice recognized alpha and beta variants of SARS-CoV-2, which supports ongoing clinical results on partial protection in vaccinated populations, despite mutations. This study identifies potential antigens for second-generation COVID-19 vaccines.

Appendiceal mucinous neoplasm, a rare diagnosis within gastrointestinal tumors. Case report.

Appendicular neoplasms are rare tumors, with an incidence of less than 0.05% among all gastrointestinal tumors. This work presents the case of a 52-year-old patient who manifested colicky pain in the right iliac fossa. Laboratory test results with bandemia and hyperbilirubinemia. Abdominal tomography with an acute appendicular inflammatory process, for which the patient was admitted for surgery. A dependent tumor of the cecum and appendicular region is observed, which compromises the ileocecal valve. The histopathological diagnosis was "low-grade appendiceal mucinous neoplasm." Appendiceal tumors are often incidental findings due to their low frequency; however, their possibility should not be dismissed.

Las neoplasias apendiculares son tumores raros, con una incidencia menor al 0.05% de todos los tumores gastrointestinales. Presentamos el caso de paciente de 52 años, quien acude por dolor cólico en fosa iliaca derecha. Estudios de laboratorio con bandemia e hiperbilirrubinemia. Tomografía abdominal con proceso inflamatorio apendicular agudo por lo que se ingresa a cirugía. Se observa tumoración dependiente de ciego y región apendicular que compromete válvula ileocecal. El diagnóstico histopatológico fue "neoplasia mucinosa apendicular de bajo grado. Los tumores de apéndice son a menudo hallazgos incidentales por su baja frecuencia, sin embargo, su posibilidad no debe descartarse.

Jacareubin inhibits TLR4-induced lung inflammatory response caused by the RBD domain of SARS-CoV-2 Spike protein.

BACKGROUND: COVID-19, the disease caused by SARS-CoV-2 virus infection, has been a major public health problem worldwide in the last 2 years. SARS-CoV-2-dependent activation of innate immune receptors contributes to the strong local and systemic inflammatory reaction associated with rapid disease evolution. The receptor-binding domain (RBD) of Spike (S) viral protein (S-RBD) is essential for virus infection and its interacting molecules in target cells are still under identification. On the other hand, the search for accessible natural molecules with potential therapeutic use has been intense and remains an active field of investigation. METHODS: C57BL6/J (control) and Toll-like receptor (TLR) 4-deficient (Lps del) mice were nebulized with recombinant S-RBD. Tumor Necrosis Factor-alpha (TNF-α) and Interleukin (IL)-6 production in bronchoalveolar lavages (BALs) was determined by enzyme-linked immunosorbent assay (ELISA). Lung-infiltrating cells recovered in BALs were quantified by hematoxylin-eosin (H&E) stain. In selected groups of animals, the natural compound Jacareubin or dexamethasone were intraperitoneally (ip) administered 2 hours before nebulization. RESULTS: A rapid lung production of TNF-α and IL-6 and cell infiltration was induced by S-RBD nebulization in control but not in Lps del mice. Pre-treatment with Jacareubin or dexamethasone prevented S-RBD-induced TNF-α and IL-6 secretion in BALs from control animals. CONCLUSIONS: S-RBD domain promotes lung TNF-α and IL-6 production in a TLR4-dependent fashion in C57BL6/J mice. Xanthone Jacareubin possesses potential anti-COVID-19 properties that, together with the previously tested anti-inflammatory activity, safety, and tolerance, make it a valuable drug to be further investigated for the treatment of cytokine production caused by SARS-CoV-2 infection.

ADAM17/MMP inhibition prevents neutrophilia and lung injury in a mouse model of COVID-19.

Severe coronavirus disease 2019 (COVID-19) is characterized by lung injury, cytokine storm, and increased neutrophil-to-lymphocyte ratio (NLR). Current therapies focus on reducing viral replication and inflammatory responses, but no specific treatment exists to prevent the development of severe COVID-19 in infected individuals. Angiotensin-converting enzyme-2 (ACE2) is the receptor for SARS-CoV-2, the virus causing COVID-19, but it is also critical for maintaining the correct functionality of lung epithelium and endothelium. Coronaviruses induce activation of a disintegrin and metalloprotease 17 (ADAM17) and shedding of ACE2 from the cell surface resulting in exacerbated inflammatory responses. Thus, we hypothesized that ADAM17 inhibition ameliorates COVID-19-related lung inflammation. We employed a preclinical mouse model using intratracheal instillation of a combination of polyinosinic:polycytidylic acid (poly(I:C)) and the receptor-binding domain of the SARS-CoV-2 spike protein (RBD-S) to mimic lung damage associated with COVID-19. Histologic analysis of inflamed mice confirmed the expected signs of lung injury including edema, fibrosis, vascular congestion, and leukocyte infiltration. Moreover, inflamed mice also showed an increased NLR as observed in critically ill COVID-19 patients. Administration of the ADAM17/MMP inhibitors apratastat and TMI-1 significantly improved lung histology and prevented leukocyte infiltration. Reduced leukocyte recruitment could be explained by reduced production of proinflammatory cytokines and lower levels of the endothelial adhesion molecules ICAM-1 and VCAM-1. Additionally, the NLR was significantly reduced by ADAM17/MMP inhibition. Thus, we propose inhibition of ADAM17/MMP as a novel promising treatment strategy in SARS-CoV-2-infected individuals to prevent the progression toward severe COVID-19.

Association between Short Hours of Sleep and Overweight/Obesity in Mexican Adolescent Population: A School-Based Cross-Sectional Study.

Background/Aim: Obesity in adolescents is increasing; as such, the aim of this study was to determine the prevalence of obesity in Mexican adolescents and examine its possible association with hours of sleep. Methods: A school-based cross-sectional study was carried out. This study included 863 adolescents aged between 11 and 16 years. The prevalence of obesity was estimated using the body mass index (BMI). The duration of sleep (and other information) was assessed by a self-reported questionnaire. The Cochran-Mantel-Hansel test for categorical variables and a general linear model for continuous variables were used to evaluate the interaction effect of BMI and sex with respect to sleeping and assessed activity conditions. Results: It was found that 47.6% of the adolescents were overweight/obese. Men were more frequently overweight/obese than women (52.6% vs. 41.8%, p = 0.002). Moreover, overweight/obese adolescents were younger and spent fewer daily hours watching television (p < 0.05). Men practiced sports more hours per week than women (p = 0.04). However, women spent more daily time on the internet (p = 0.05), and overweight/obese adolescent women slept fewer hours than overweight/obese men and adolescents with normal weight (p = 0.008). Conclusions: The development of strategies for the prevention of overweight/obesity and the improvement of sleep duration should include a gender perspective to improve health habits in Mexican adolescents.

Recombinant Antigens Based on Non-Glycosylated Regions from RBD SARS-CoV-2 as Potential Vaccine Candidates against COVID-19.

The Receptor-Binding Domain (RBD) of the Spike (S) protein from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has glycosylation sites which can limit the production of reliable antigens expressed in prokaryotic platforms, due to glycan-mediated evasion of the host immune response. However, protein regions without glycosylated residues capable of inducing neutralizing antibodies could be useful for antigen production in systems that do not carry the glycosylation machinery. To test this hypothesis, the potential antigens NG06 and NG19, located within the non-glycosylated S-RBD region, were selected and expressed in Escherichia coli, purified by FPLC and employed to determine their immunogenic potential through detection of antibodies in serum from immunized rabbits, mice, and COVID-19 patients. IgG antibodies from sera of COVID-19-recovered patients detected the recombinant antigens NG06 and NG19 (A450 nm = 0.80 ± 0.33; 1.13 ± 0.33; and 0.11 ± 0.08 for and negatives controls, respectively). Also, the purified antigens were able to raise polyclonal antibodies in animal models evoking a strong immune response with neutralizing activity in mice model. This research highlights the usefulness of antigens based on the non-N-glycosylated region of RBD from SARS-CoV-2 for candidate vaccine development.

Recombinant Protein Expression and Purification of N, S1, and RBD of SARS-CoV-2 from Mammalian Cells and Their Potential Applications.

The coronavirus disease 2019 (COVID-19) pandemic has reached an unprecedented level. There is a strong demand for diagnostic and serological supplies worldwide, making it necessary for countries to establish their own technologies to produce high-quality biomolecules. The two main viral antigens used for the diagnostics for severe acute respiratory syndrome coronavirus (SARS-CoV-2) are the structural proteins spike (S) protein and nucleocapsid (N) protein. The spike protein of SARS-CoV-2 is cleaved into S1 and S2, in which the S1 subunit has the receptor-binding domain (RBD), which induces the production of neutralizing antibodies, whereas nucleocapsid is an ideal target for viral antigen-based detection. In this study, we designed plasmids, pcDNA3.1/S1 and pcDNA3.1/N, and optimized their expression of the recombinant S1 and N proteins from SARS-CoV-2 in a mammalian system. The RBD was used as a control. The antigens were successfully purified from Expi293 cells, with high yields of the S1, N, and RBD proteins. The immunogenic abilities of these proteins were demonstrated in a mouse model. Further, enzyme-linked immunosorbent assays with human serum samples showed that the SARS-CoV-2 antigens are a suitable alternative for serological assays to identify patients infected with COVID-19.

Lack of Association of Coffee Consumption with the Prevalence of Self-Reported Type 2 Diabetes Mellitus in a Mexican Population: A Cross-Sectional Study.

It is estimated that almost 366 million people are currently suffering from diabetes mellitus worldwide. However, it has been suggested that coffee consumption has a protective effect against the development of type 2 diabetes mellitus. This association has been observed in many regions around the world. Today, there are no reports in Mexico regarding this association. Therefore, the aim of this study was to assess the association between coffee intake and self-reported type 2 diabetes mellitus in the southeastern part of Mexico. This study included 1277 residents of Comalcalco, a municipality of Tabasco State, Mexico. We calculated the prevalence for diabetes and performed multivariate analysis using multiple logistic regressions to evaluate the combined association with type 2 diabetes mellitus. The prevalence of the diabetes was 12.52% (95% CI: 10.67⁻14.38). The majority of people surveyed (77.29%; 95% CI: 74.95⁻79.60) indicated they were coffee drinkers. The results of multivariate analysis showed a non-significant relationship between the number of cups of coffee drank and type 2 diabetes mellitus. The adjusted odds ratio gave the following values: 1.20, (95% CI: 0.59⁻2.41) for non-daily consumption; 1.66 (0.82⁻3.34), for 1 cup of coffee peer day, and 1.49 (0.78⁻2.86) for 2⁻3 cups. Subsequently, an adjustment was made for age, gender, marital status, education, alcohol consumption, and cigarette smoking. In our population, we did not observe an association between coffee intake and its protective relationship with self-reported type 2 diabetes mellitus.

Gender differences of suicides in children and adolescents: Analysis of 167 suicides in a Mexican population from 2003 to 2013.

Suicide is the second cause of death in youth population. The aim of the present study was to analyze demographic characteristics and suicide methods used, as well as to identify gender differences among Mexican children and adolescents (aged 10-17 years) that committed suicide. Between January 2003 and December 2013, 167 suicides of children and adolescents between 10 and 17 years of age were documented by the Secretary of Health of the state of Tabasco, Mexico. All sociodemographic characteristics were compared according to gender. Our sample included 67.7% males and 32.3% females (male to female 2.1:1). The predominant marital status was single (89.6%) and hanging (93.7%) was the principal method of suicide used. Both female and male adolescents were predominantly students (50%); however, female adolescents were more frequently married (17%) and were housewives (26.4%). Our results identified that hanging is the principal suicide method used by children and adolescents in Mexican population; we also detected main gender differences in terms of poisoning/drug toxicity as the method used, occupation and marital status. These results should be taken into consideration when designing suicide prevention programs due to the differences found by gender.

Percepción de conflicto intergrupal y su relación con la adhesión a creencias esencialistas / Perception of the intergroup conflict and its correlation with adherence to essentialist beliefs

La presente investigación estudia cómo se vinculan la percepción de un conflicto entre dos grupos (endogrupo y exogrupo) y la adherencia a creencias esencialistas. La hipótesis de trabajo es que la percepción de un mayor nivel de conflicto entre el endogrupo y un exogrupo se asocia a un aumento en las creencias esencialistas, es decir, se vería incrementado al pensar que los grupos existen como consecuencia de elementos profundos compartidos por sus miembros, que los convierten en grupos reales y naturales (no creados socialmente). Esta hipótesis se enmarca en una nueva orientación respecto de la aplicación de esta teoría implícita, en el sentido de tratar de comprender -más que sus consecuencias negativas- los virtuales beneficios secundarios para el grupo que opera con ellas. En dos estudios similares (N1 = 180, N2 = 162), que utilizaron un muestreo no aleatorio intencional y un diseño no experimental transversal y correlacional, se midieron las variables "percepción de conflicto" y "creencias esencialistas respecto al propio grupo y a otro grupo". Los resultados van en la dirección de nuestras predicciones e indican que, efectivamente, ambas variables se encuentran vinculadas. Se discute en torno a la posible interpretación causal de estos resultados y sus limitaciones.

This research study covers the relation between perception of conflict (in two groups: intragroup and extragroup) and adherence to essentialist beliefs. The hypothesis made Social identity states that perception of a higher conflict level between intragroup and extragroup is associated with an increase in essentialist beliefs. This means that this increase occurs pursuant to the belief that groups exist as a consequence of sharing profound elements amongst members, thus becoming real and natural (not socially created) groups. This hypothesis establishes a new approach to the application of this implicit theory, as it seeks to understand not only its negative consequences, but also its potential ancillary benefits for the groups which operate under such negative consequences. The two variables were measured in two similar studies (N1=180, N2=169) which used non-random sampling and a non-experimental cross-correlational design.The variables used were "conflict perception" and "essentialist intragroup extragroup beliefs".The results are in line with our predictions, showing that both variables are related. A discussion is presented on potential causal interpretation of these results and their limitations.