Occult Hepatitis B Virus Infection in Hepatic Diseases and Its Significance for the WHO's Elimination Plan of Viral Hepatitis.

Liver damage can progress through different stages, resulting in cirrhosis or hepatocellular carcinoma (HCC), conditions that are often associated with viral infections. Globally, 42% and 21% of cirrhosis cases correlate with HBV and HCV, respectively. In the Americas, the prevalence ranges from 1% to 44%. The WHO has the goal to eliminate viral hepatitis, but it is important to consider occult HBV infection (OBI), a clinical condition characterized by the presence of HBV genomes despite negative surface antigen tests. This review aims to provide an overview of recent data on OBI, focusing on its role in the development of hepatic diseases and its significance in the WHO Viral Hepatitis Elimination Plan. Specific HBV gene mutations have been linked to HCC and other liver diseases. Factors related to the interactions between OBI and mutated viral proteins, which induce endoplasmic reticulum stress and oxidative DNA damage, and the potential role of HBV integration sites (such as the TERT promoter) have been identified in HCC/OBI patients. Health initiatives for OBI research in Latin American countries are crucial to achieving the WHO's goal of eradicating viral hepatitis by 2030, given the difficulty in diagnosing OBI and its unclear association with hepatic diseases.

Cupiennius spiders (Trechaleidae) from southern Mexico: DNA barcoding, venomics, and biological effect.

Background: Members of the genus Cupiennius Simon, 1891 are categorized as wandering spiders and are part of the family Trechaleidae. The genomics and proteomics of Cupiennius spiders from North America remain uncharacterized. The present study explores for the first time molecular data from the endemic species Cupiennius chiapanensis Medina, 2006, and also presents new data for Cupiennius salei (Keyserling, 1878), both collected in southern Mexico. Methods: In total, 88 Cupiennius specimens were collected from southern Mexico and morphologically identified. DNA was extracted and the mitochondrial COI fragment was amplified. COI sequences were analyzed, and a phylogenetic tree was inferred for species from the Americas. Genetic diversity was analyzed using haplotype networks and gene distances. Venom was obtained from C. chiapanensis and C. salei by electrostimulation. The venom was separated by HPLC, visualized using SDS-PAGE, and quantified for use in toxicity bioassays in mice and insects. Results: Analysis of COI sequences from C. chiapanensis showed 94% identity with C. salei, while C. salei exhibited 94-97% identity with sequences from Central and South American conspecifics. The venom from C. chiapanensis exhibited toxic activity against crickets. Venoms from C. chiapanensis and C. salei caused death in Anastrepha obliqua flies. Analysis of venom fractions from C. salei and C. chiapanensis revealed molecular masses of a similar size as some previously reported toxins and neurotoxic components. We determined the amino acid sequences of ChiaTx1 and ChiaTx2, toxins that are reported here for the first time and which showed toxicity against mice and insects. Conclusion: Our work is the first to report COI-based DNA barcoding sequences from southern Mexican Cupiennius spiders. Compounds with toxic activity were identified in venom from both species.

Unlocking cellular traffic jams: olive oil-mediated rescue of CNG mutant channels.

One of the reasons to suggest olive oil consumption for a healthy life is its potential to induce robust lipidomic remodeling through membrane modification by dietary lipids. This remodeling might, in turn, modulate essential lipid-protein interactions while maintaining accurate transmembrane protein/domain orientation. Oleic acid, the primary compound in olive oil, has been suggested as a modulator of ion channel function. In this study, we explored whether this lipid could rescue the trafficking of mutated transmembrane proteins. In our initial approach, we supplemented the cell culture medium of HEK-293 cells expressing cyclic nucleotide channels tagged using green fluorescent protein (CNG-GFP) with olive oil or oleic acid. In addition to wild-type channels, we also expressed R272Q and R278W mutant channels, two non-functional intracellularly retained channels related to retinopathies. We used fluorescence microscopy and patch-clamp in the inside-out configuration to assess changes in the cell localization and function of the tested channels. Our results demonstrated that olive oil and oleic acid facilitated the transport of cyclic nucleotide-gated R272Q mutant channels towards the plasma membrane, rendering them electrophysiologically functional. Thus, our findings reveal a novel property of olive oil as a membrane protein traffic inductor.

Cupiennius spiders (Trechaleidae) from southern Mexico: DNA barcoding, venomics, and biological effect

Background: Members of the genus Cupiennius Simon, 1891 are categorized as wandering spiders and are part of the family Trechaleidae. The genomics and proteomics of Cupiennius spiders from North America remain uncharacterized. The present study explores for the first time molecular data from the endemic species Cupiennius chiapanensis Medina, 2006, and also presents new data for Cupiennius salei (Keyserling, 1878), both collected in southern Mexico. Methods: In total, 88 Cupiennius specimens were collected from southern Mexico and morphologically identified. DNA was extracted and the mitochondrial COI fragment was amplified. COI sequences were analyzed, and a phylogenetic tree was inferred for species from the Americas. Genetic diversity was analyzed using haplotype networks and gene distances. Venom was obtained from C. chiapanensis and C. salei by electrostimulation. The venom was separated by HPLC, visualized using SDS-PAGE, and quantified for use in toxicity bioassays in mice and insects. Results: Analysis of COI sequences from C. chiapanensis showed 94% identity with C. salei, while C. salei exhibited 94-97% identity with sequences from Central and South American conspecifics. The venom from C. chiapanensis exhibited toxic activity against crickets. Venoms from C. chiapanensis and C. salei caused death in Anastrepha obliqua flies. Analysis of venom fractions from C. salei and C. chiapanensis revealed molecular masses of a similar size as some previously reported toxins and neurotoxic components. We determined the amino acid sequences of ChiaTx1 and ChiaTx2, toxins that are reported here for the first time and which showed toxicity against mice and insects. Conclusion: Our work is the first to report COI-based DNA barcoding sequences from southern Mexican Cupiennius spiders. Compounds with toxic activity were identified in venom from both species.(AU)

Inequalities by sex on remaining teeth in adults: A decomposition analysis.

OBJECTIVE: To identify which social determinants of health explain the gap in the remaining teeth between men and women. METHODS: A secondary analysis of data from the Chilean National Health Survey (CNHS) 2016-2017 was performed on the number of remaining teeth in adults. The explanatory variables were organized into structural and intermediate social determinants of health according to the WHO framework. The contribution of both groups and the contribution of each individual explanatory variable to the remaining teeth gap was estimated using the Blinder-Oaxaca decomposition analysis. RESULTS: The predicted average number of remaining teeth for men was 23.4 and 21.0 for women, thus a mean difference of 2.4 teeth. 49.8% of the inequality between men and women was due to the different distribution (endowments) of the predictors in the model. Among them, structural determinants of health, namely education level (15.8%) and employment status (17.8%), contributed the most. Intermediate determinants had no relevant contribution to explain the gap. CONCLUSIONS: Results revealed that the difference in the mean number of remaining teeth between men and women was mainly explained by two structural determinants: education level and employment status. The lack of explanatory power of intermediate determinants and the large explanatory power of structural determinants means that tackling oral health inequity in Chile requires strong political commitment. The role of intersectoral and intersectional public policies to address gender inequalities in oral health in Chile is discussed.

Broad-Spectrum Antifungal, Biosurfactants and Bioemulsifier Activity of Bacillus subtilis subsp. spizizenii-A Potential Biocontrol and Bioremediation Agent in Agriculture.

In this study, the antifungal, biosurfactant and bioemulsifying activity of the lipopeptides produced by the marine bacterium Bacillus subtilis subsp. spizizenii MC6B-22 is presented. The kinetics showed that at 84 h, the highest yield of lipopeptides (556 mg/mL) with antifungal, biosurfactant, bioemulsifying and hemolytic activity was detected, finding a relationship with the sporulation of the bacteria. Based on the hemolytic activity, bio-guided purification methods were used to obtain the lipopeptide. By TLC, HPLC and MALDI-TOF, the mycosubtilin was identified as the main lipopeptide, and it was further confirmed by NRPS gene clusters prediction based on the strain's genome sequence, in addition to other genes related to antimicrobial activity. The lipopeptide showed a broad-spectrum activity against ten phytopathogens of tropical crops at a minimum inhibitory concentration of 400 to 25 µg/mL and with a fungicidal mode of action. In addition, it exhibited that biosurfactant and bioemulsifying activities remain stable over a wide range of salinity and pH and it can emulsify different hydrophobic substrates. These results demonstrate the potential of the MC6B-22 strain as a biocontrol agent for agriculture and its application in bioremediation and other biotechnological fields.

Transcriptome analysis of the spider Phonotimpus pennimani reveals novel toxin transcripts.

Background: Phonotimpus pennimani (Araneae, Phrurolithidae) is a small-sized (3-5 mm) spider endemic to the Tacaná volcano in Chiapas, Mexico, where it is found in soil litter of cloud forests and coffee plantations. Its venom composition has so far not been investigated, partly because it is not a species of medical significance. However, it does have an important impact on the arthropod populations of its natural habitat. Methods: Specimens were collected in Southeastern Mexico (Chiapas) and identified taxonomically by morphological characteristics. A partial sequence from the mitochondrial gene coxI was amplified. Sequencing on the Illumina platform of a transcriptome library constructed from 12 adult specimens revealed 25 toxin or toxin-like genes. Transcripts were validated (RT-qPCR) by assessing the differential expression of the toxin-like PpenTox1 transcript and normalising with housekeeping genes. Results: Analysis of the coxI-gene revealed a similarity to other species of the family Phrurolithidae. Transcriptome analysis also revealed similarity with venom components of species from the families Ctenidae, Lycosidae, and Sicariidae. Expression of the toxin-like PpenTox1 gene was different for each developmental stage (juvenile or adult) and also for both sexes (female or male). Additionally, a partial sequence was obtained for the toxin-like PpenTox1 from DNA. Conclusion: Data from the amplification of the mitochondrial coxI gene confirmed that P. pennimani belongs to the family Phrurolithidae. New genes and transcripts coding for venom components were identified.

Bacterial Diversity Associated with Anastrepha obliqua Males Change Under Mass-Rearing Conditions and with Irradiation.

Recent advances in understanding the symbiotic interactions between bacteria and fruit flies have shown that they are relevant for mass rearing and the sterile insect technique (SIT). SIT involves mass production and release of sterile insects that would copulate with their wild conspecifics and thus decrease the population growth rate. The irradiation process used to sterilize mass-reared flies can modify the diversity and structure of the midgut bacterial communities, which could affect sterile male survival, flight capacity, and sexual competitiveness. Our aim was to compare bacterial communities in the midgut of wild and mass-reared Anastrepha obliqua (Macquart) males irradiated at 0, 60, and 80 Gy. After adult's emergence, their midguts were dissected, DNA was extracted, and high-throughput sequencing of the V3-V4 region of the 16S rDNA gene was performed. A total of 11 phyla, 17 classes, 47 families, and 52 genera of bacteria were identified. The most representative phylum was Proteobacteria and the predominant family was Enterobacteriaceae. We found that wild males had a different intestinal bacterial community from mass-reared males. In addition, irradiation at 60 and 80 Gy caused changes in the diversity and structure of the midgut microbiota of these sterile males, suggesting that mass rearing and irradiation cause artificial selection of the bacterial communities in the gut of A. obliqua males.

Fungal diversity in shade-coffee plantations in Soconusco, Mexico.

Background: As forested natural habitats disappear in the world, traditional, shade-coffee plantations offer an opportunity to conserve biodiversity and ecosystem services. Traditional coffee plantations maintain a diversity of tree species that provide shade for coffee bushes and, at the same time, are important repositories for plants and animals that inhabited the original cloud forest. However, there is still little information about shade-coffee plantation's fungal diversity despite their relevance for ecosystem functioning as decomposers, symbionts and pathogens. Specifically, it is unknown if and what mycorrhizae-forming fungi can be found on the branches and trunks of coffee bushes and trees, which hold a diversity of epiphytes. Here, we evaluate fungal communities on specific plant microsites on both coffee bushes and shade trees. We investigate the ecological roles played by this diversity, with a special focus on mycorrhizae-forming fungi that may enable the establishment and development of epiphytic plants. Methods: We collected 48 bark samples from coffee bushes and shade trees (coffee; tree), from four plant microsites (upper and lower trunks, branches and twigs), in two shade-coffee plantations in the Soconusco region in southern Mexico, at different altitudes. We obtained ITS amplicon sequences that served to estimate alpha and beta diversity, to assign taxonomy and to infer the potential ecological role played by the detected taxa. Results: The bark of shade trees and coffee bushes supported high fungal diversity (3,783 amplicon sequence variants). There were no strong associations between community species richness and collection site, plant type or microsite. However, we detected differences in beta diversity between collection sites. All trophic modes defined by FUNGuild database were represented in both plant types. However, when looking into guilds that involve mycorrhizae formation, the CLAM test suggests that coffee bushes are more likely to host taxa that may function as mycorrhizae. Discussion: We detected high fungal diversity in shade-coffee plantations in Soconusco, Chiapas, possibly remnants of the original cloud forest ecosystem. Several mycorrhiza forming fungi guilds occur on the bark of coffee bushes and shade trees in this agroecosystem, with the potential of supporting epiphyte establishment and development. Thus, traditional coffee cultivation could be part of an integrated strategy for restoration and conservation of epiphytic populations. This is particularly relevant for conservation of threatened species of Orchidaceae that are highly dependent on mycorrhizae formation.

Effect of a Probiotic-Enriched Diet on Sexual Competitiveness, Pheromone Emission, and Cuticular Hydrocarbons of Sterile and Fertile Anastrepha ludens (Diptera: Tephritidae).

The sterile insect technique has been used for the eradication or control of numerous tephritid fruit flies. However, mass-rearing and sterilization can affect the microbiota and sexual performance of male tephritid fruit flies. Despite the addition of postteneral protein food which contributes to the enhancement of the sexual performance of mass-reared males, in some cases, they are less competitive than their wild counterparts. Alternatively, the addition of probiotics may improve the sexual performance of mass-reared sterile males. In this study, we evaluated the effect of a postteneral Lactobacillus casei-enriched diet on the sexual competitivity, pheromone emission, and cuticular hydrocarbons of mass-reared sterile and fertile Anastrepha ludens (Loew) (Diptera: Tephritidae) males. Flies were fed either with sugar, standard diet (sugar and protein, 3:1), sugar + probiotic, or standard diet + probiotic. The addition of the probiotic improved the sexual competitivity of fertile and sterile males that were devoid of protein but led to a negative effect on males fed with a standard diet. As compared to males that were fed with the standard diet + probiotic/only sugar, the males fed with the standard diet or those fed on sugar + probiotic displayed a higher number of mating instances. Sterile males that fed on sugar + probiotic had a higher relative amount of anastrephine, epianastrephine, n-methyl octacosane, and 2-methyl triacontane than those fed on sugar only. Overall, these compounds were common in the treatments where males had the best sexual performance. Our results suggest that the probiotics offer nutritional advantages to males whose food lacks protein.

Tween 80 Improves the Acid-Fast Bacilli Quantification in the Magnetic Nanoparticle-Based Colorimetric Biosensing Assay (NCBA).

Despite its reduced sensitivity, sputum smear microscopy (SSM) remains the main diagnostic test for detecting tuberculosis in many parts of the world. A new diagnostic technique, the magnetic nanoparticle-based colorimetric biosensing assay (NCBA) was optimized by evaluating different concentrations of glycan-functionalized magnetic nanoparticles (GMNP) and Tween 80 to improve the acid-fast bacilli (AFB) count. Comparative analysis was performed on 225 sputum smears: 30 with SSM, 107 with NCBA at different GMNP concentrations, and 88 with NCBA-Tween 80 at various concentrations and incubation times. AFB quantification was performed by adding the total number of AFB in all fields per smear and classified according to standard guidelines (scanty, 1+, 2+ and 3+). Smears by NCBA with low GMNP concentrations (≤1.5 mg/mL) showed higher AFB quantification compared to SSM. Cell enrichment of sputum samples by combining NCBA-GMNP, incubated with Tween 80 (5%) for three minutes, improved capture efficiency and increased AFB detection up to 445% over SSM. NCBA with Tween 80 offers the opportunity to improve TB diagnostics, mainly in paucibacillary cases. As this method provides biosafety with a simple and inexpensive methodology that obtains results in a short time, it might be considered as a point-of-care TB diagnostic method in regions where resources are limited.

Hemicellulolytic bacteria in the anterior intestine of the earthworm Eisenia fetida (Sav.).

Tropical agriculture produces large amounts of lignocellulosic residues that can potentially be used as a natural source of value-added products. The complexity of lignocellulose makes industrial-scale processing difficult. New processing techniques must be developed to improve the yield and avoid this valuable resource going to waste. Hemicelluloses comprise a variety of polysaccharides with different backbone compositions and decorations (such as methylations and acetylations), and form part of an intricate framework that confers structural stability to the plant cell wall. Organisms that are able to degrade these biopolymers include earthworms (Eisenia fetida), which can rapidly decompose a wide variety of lignocellulosic substrates. This ability probably derives from enzymes and symbiotic microorganisms in the earthworm gut. In this work, two substrates with similar C/N ratios but different hemicellulose content were selected. Palm fibre and coffee husk have relatively high (28%) and low (5%) hemicellulose contents, respectively. A vermicomposting mixture was prepared for the earthworms to feed on by mixing a hemicellulose substrate with organic market waste. Xylanase activity was determined in earthworm gut and used as a selection criterion for the isolation of hemicellulose-degrading bacteria. Xylanase activity was similar for both substrates, even though their physicochemical properties principally pH and electrical conductivity, as shown by the MANOVA analysis) were different for the total duration of the experiment (120 days). Xylanolytic strains isolated from earthworm gut were identified by sequence analysis of the 16S rRNA gene. Our results indicate that the four Actinobacteria, two Proteobacteria, and one Firmicutes isolated are active participants of the xylanolytic degradation by microbiota in the intestine of E. fetida. Most bacteria were more active at pH 7 and 28 °C, and those with higher activities are reported as being facultatively anaerobic, coinciding with the microenvironment reported for the earthworm gut. Each strain had a different degradative capacity.

Brevipalpus mites associated with coffee plants (Coffea arabica and C. canephora) in Chiapas, Mexico.

Tenuipalpid mites of the genus Brevipalpus are of significant economic and quarantine importance in agriculture. They can damage and vector phytopathogenic viruses in coffee plantations and other crops. In this study, we focused on: identification of the Brevipalpus species, assessment of the spread of Brevipalpus-associated viruses (CoRSV, CiLV-N, CiLVC and CiLVC2), and mite population fluctuations over the course of 1 year. The study was conducted in coffee plantations in Soconusco, a coffee-producing region in Chiapas, Mexico. The collected mites of the Brevipalpus phoenicis sensu lato species complex (635) were identified as Brevipalpus papayensis (80.2%) and B. yothersi (19.8%) based on morphological and molecular characteristics. Their population abundance was low and there were no indications for virosis. The highest mite abundance was recorded in August-September and the lowest in February-March. An interaction was observed between mite abundance and coffee species in open-growth and shaded cultivation at various altitudes. Brevipalpus papayensis was most abundant in Coffea arabica var. Bourbon, in shaded (80%) growing conditions at an altitude of 1300 m above sea level. In C. canephora (in open-growth cultivation conditions at low altitude), B. yothersi was more abundant than in C. arabica, and as abundant as B. papayensis. We are of the opinion that, at this moment, B. papayensis and B. yothersi do not present risks to the production of coffee for the studied plantations. However, as the coffee-producing regions of Mexico are ecologically diverse, it will be important to continue examining the status of Brevipalpus mite populations in other regions in Mexico.

Ethnic Identity and Well-Being of Andean Indigenous People: The Effect of Individualistic and Collectivist Value Orientations.

The aim of this research was to evaluate the mediating effect of the value orientations of collectivism and individualism on the relationship between ethnic identity and well-being, the latter conceived from the worldview of Andean natives. For this purpose, under an observational and cross-sectional design, 395 Lickan-Antay adults (57% women) living in areas of indigenous development and in two cities in northern Chile were surveyed. We used the Lickan-Antay BLA32 well-being scale, a short version of the Portrait 21 Values Questionnaire to measure individualistic and collectivistic values, and an adapted version of the Ethnic Identity Scale. The results show that ethnic identity had a direct positive effect on all three dimensions of well-being (harmony with community life, ethnic harmony and harmony with nature), and total indirect effects on all five dimensions of well-being, one of them originating mainly from collectivist orientations. Individualistic orientations also showed a positive, though less intense, mediating effect on well-being. We conclude that collectivist and individualistic motivational patterns coexist in Lickan-Antay natives and explain an important part of the relationship between ethnic identity and well-being. Finally, we discuss our results and suggest replication of this study in other ethnic contexts to assess the generalizability of these findings to other native peoples of the Andean region of South America.

UBA2 variants underlie a recognizable syndrome with variable aplasia cutis congenita and ectrodactyly.

PURPOSE: The human chromosome 19q13.11 deletion syndrome is associated with a variable phenotype that includes aplasia cutis congenita (ACC) and ectrodactyly as specific features. UBA2 (ubiquitin-like modifier-activating enzyme 2) lies adjacent to the minimal deletion overlap region. We aimed to define the UBA2-related phenotypic spectrum in humans and zebrafish due to sequence variants and to establish the mechanism of disease. METHODS: Exome sequencing was used to detect UBA2 sequence variants in 16 subjects in 7 unrelated families. uba2 loss of function was modeled in zebrafish. Effects of human missense variants were assessed in zebrafish rescue experiments. RESULTS: Seven human UBA2 loss-of-function and missense sequence variants were detected. UBA2-phenotypes included ACC, ectrodactyly, neurodevelopmental abnormalities, ectodermal, skeletal, craniofacial, cardiac, renal, and genital anomalies. uba2 was expressed in zebrafish eye, brain, and pectoral fins; uba2-null fish showed deficient growth, microcephaly, microphthalmia, mandibular hypoplasia, and abnormal fins. uba2-mRNAs with human missense variants failed to rescue nullizygous zebrafish phenotypes. CONCLUSION: UBA2 variants cause a recognizable syndrome with a wide phenotypic spectrum. Our data suggest that loss of UBA2 function underlies the human UBA2 monogenic disorder and highlights the importance of SUMOylation in the development of affected tissues.

Identification of mutations in the S gene of hepatitis B virus in HIV positive Mexican patients with occult hepatitis B virus infection.

INTRODUCTION AND AIM: Occult hepatitis B virus infection (OBI) is characterized by the presence of replication-competent hepatitis B virus (HBV) DNA in the liver and/or serum of patients with undetectable levels of the HBV surface antigen (HBsAg). Due to the shared infection routes HIV positive patients are at higher risk of developing OBI, thus, the aim of this study was to determine the frequency of OBI in Mexican HIV-infected patients and to identify mutations in the HBV S gene that could be associated to the development of OBI. MATERIALS AND METHODS: Plasma samples from 50 HIV-infected patients with undetectable levels of the HBsAg were obtained and analyzed. The Core, PreS and S genes were amplified by nested PCR and sequenced by the Sanger method. To analyze HBV diversity in the OBI-positive patients, ten sequences of 762bp from the HBV S gene were selected, cloned, and subsequently sequenced for mutational analyses. RESULTS: OBI infection was found with a frequency of 36% (18/50). All the HBV sequences corresponded to the H genotype. The most common mutations were: C19Y, Q129H, E164D, and I195M, with a frequency of 44%, 36%, 39% and 48% respectively. CONCLUSIONS: In this study, we report the presence of OBI in a cohort of Mexican HIV-infected patients with an overall prevalence of 36%. Mutational analyses revealed that four non-silent mutations were frequent in different regions of the HBsAg gene, suggesting that they might be associated to the development of OBI in this population, nevertheless, further studies are required to determine their role in the pathogenesis of OBI.

Assistance for Folding of Disease-Causing Plasma Membrane Proteins.

An extensive catalog of plasma membrane (PM) protein mutations related to phenotypic diseases is associated with incorrect protein folding and/or localization. These impairments, in addition to dysfunction, frequently promote protein aggregation, which can be detrimental to cells. Here, we review PM protein processing, from protein synthesis in the endoplasmic reticulum to delivery to the PM, stressing the main repercussions of processing failures and their physiological consequences in pathologies, and we summarize the recent proposed therapeutic strategies to rescue misassembled proteins through different types of chaperones and/or small molecule drugs that safeguard protein quality control and regulate proteostasis.

Specification issues in nonlinear sem: the moderation that wasn't / Problemas de especificación en SEM no lineal: la moderación que no lo era

BACKGROUND: Analysis of interaction or moderation effects between latent variables is a common requirement in the social sciences. However, when predictors are correlated, interaction and quadratic effects become more alike, making them difficult to distinguish. As a result, when data are drawn from a quadratic population model and the analysis model specifies interactions only, misleading results may be obtained. METHOD: This article addresses the consequences of different types of specification error in nonlinear structural equation models using a Monte Carlo study. RESULTS: Results show that fitting a model with interactions when quadratic effects are present in the population will almost certainly lead to erroneous detection of moderation effects, and that the same is true in the opposite scenario. Simultaneous estimation of interactions and quadratic effects yields correct results. CONCLUSIONS: Simultaneous estimation of interaction and quadratic effects prevents detection of spurious or misleading nonlinear effects. Results are discussed and recommendations are offered to applied researchers

ANTECEDENTES: el análisis de efectos de interacción o moderación entre variables latentes es común en ciencias sociales. Sin embargo, cuando los predictores están correlacionados, los efectos de interacción y cuadráticos se vuelven parecidos, haciendo difícil su distinción. Así, cuando los datos provienen de un modelo de cuadrático a nivel poblacional y el modelo de análisis solo especifica interacciones, se pueden obtener resultados engañosos. MÉTODO: este artículo aborda las consecuencias de diferentes tipos de errores de especificación en modelos de ecuaciones estructurales no lineales utilizando un estudio de Monte Carlo. RESULTADOS: los resultados muestran que estimar un modelo con interacciones cuando en la población hay efectos cuadráticos conducirá a una detección equivocada de efectos de moderación con casi plena seguridad, y lo mismo ocurrirá en el escenario opuesto. La estimación simultánea de interacciones y efectos cuadráticos en el modelo conduce a resultados correctos. CONCLUSIONES: la estimación simultánea de efectos de interacción y cuadráticos permite evitar detectar efectos no lineales espurios o engañosos. Los resultados se discuten para ofrecer recomendaciones a los investigadores aplicados

Specification issues in nonlinear SEM: The moderation that wasn't.

BACKGROUND: Analysis of interaction or moderation effects between latent variables is a common requirement in the social sciences. However, when predictors are correlated, interaction and quadratic effects become more alike, making them difficult to distinguish. As a result, when data are drawn from a quadratic population model and the analysis model specifies interactions only, misleading results may be obtained. METHOD: This article addresses the consequences of different types of specification error in nonlinear structural equation models using a Monte Carlo study. RESULTS: Results show that fitting a model with interactions when quadratic effects are present in the population will almost certainly lead to erroneous detection of moderation effects, and that the same is true in the opposite scenario. Simultaneous estimation of interactions and quadratic effects yields correct results. CONCLUSIONS: Simultaneous estimation of interaction and quadratic effects prevents detection of spurious or misleading nonlinear effects. Results are discussed and recommendations are offered to applied researchers.

Biodegradation of NSAIDs and their effect on the activity of ligninolytic enzymes from Pleurotus djamor.

In this work, the white-rot fungus Pleurotus djamor was used for the first time to determine the degradation kinetics of the nonsteroidal anti-inflammatory drugs diclofenac, naproxen and, ketoprofen, either individually or in mixtures, in submerged cultures. Removal of 93% individual diclofenac and 99% diclofenac in mixtures with naproxen and ketoprofen at 6 h of incubation with the fungus was achieved. The elimination levels of naproxen and ketoprofen individually were 90% and 87%, respectively, after 48 h of incubation. However, the removal levels of these compounds in mixtures were 85% and 83%, respectively. On the other hand, during the degradation kinetics analysis, the enzymatic activities of laccases, manganese peroxidases, and lignin peroxidases were evaluated, yielding values of 3700, 270 and 31 U/L, respectively. Additionally, it was demonstrated that during degradation of diclofenac or the three drugs mixed in the submerged cultures, the enzymatic activity of extracellular laccases expressed by P. djamor increased by 200% and 300%, respectively. The activity of manganese peroxides increased by 126% with diclofenac and 138% when the mixture of drugs was added to the cultures. On the other hand, lignin peroxidase only increased activity by 123% with the drug mixture.