Contextuality and context-sensitivity in probabilistic models of cognition.

The context-sensitivity of cognition has been demonstrated across a wide range of cognitive functions such as perception, memory, judgement and decision making. A related term, 'contextuality', has appeared from the field of quantum cognition, with mounting empirical evidence demonstrating that cognitive phenomena are sometimes contextual. Contextuality is a subtle notion that influences how we must view the properties of the cognitive phenomenon being studied. This article addresses the questions: What does it mean for a cognitive phenomenon to be contextual? What are the implications of contextuality for probabilistic models of cognition? How does contextuality differ from context-sensitivity? Starting from George Boole's "conditions of possible experience", we argue that a probabilistic model of a cognitive phenomenon is necessarily subject to an assumption of realism. By this we mean that the phenomenon being studied is assumed to have cognitive properties with a definite value independent of observation. In contrast, quantum cognition holds that a cognitive property maybe indeterminate, i.e., its properties do not have well established values prior to observation. We argue that indeterminacy is sufficient for incompatibility between cognitive properties. In turn, incompatibility is necessary for their contextuality. The significance of this argument for cognitive psychology is the following:if a cognitive phenomenon is found to be contextual, then there is reason to believe it may be indeterminate. We illustrate by means of two crowdsourced experiments how context-sensitivity and contextuality of cognitive properties in the form of facial trait judgements can be characterized from empirical data. Finally, we conceptually and formally contrast contextuality with context-sensitivity. We propose that both involve a form of context dependence, with causality being the differentiating factor: the context dependence in context-sensitivity has a causal basis, whereas the context dependence in contextuality is acausal. The resulting implications for probabilistic models of cognition are discussed.

Sociodemographic disparities in oral health-related quality of life of schoolchildren in rural and urban areas.

OBJECTIVE: To assess the association between residence place, socioeconomic conditions and oral health-related quality of life (OHRQoL) among schoolchildren from southern Brazil. METHODS: Participants were 9-14-year-old schoolchildren from rural and urban municipal schools from Rosário do Sul, Brazil. The Child Perceptions Questionnaire (CPQ11-14) was used to assess OHRQoL. A structured questionnaire collected data on sociodemographic condition (family income), residence place (urban or rural), use of dental services, and behavioral variables. Clinical oral examination recorded the presence of missing teeth and the gingival bleeding index. Multilevel Poisson regression analysis with a hierarchical approach assessed the association between predictors and CPQ11-14 scores. Rate ratios (RR) and 95% confidence intervals (CI) were estimated. RESULTS: A total of 373 schoolchildren were included (rural area=122; urban area=251), with a mean CPQ11-14 score of 11.83, ranging from 0 to 42. Low-income schoolchildren living in rural areas had 15% higher CPQ11-14 scores than high-income schoolchildren living in urban areas. In urban areas, family income predicted OHRQoL, with low-income schoolchildren having 9% higher CPQ11-14 scores than high-income children. In rural areas, schoolchildren with low household income had 19% higher CPQ11-14 scores than high-income children. CONCLUSION: Schoolchildren from low-income families had a poorer OHRQoL irrespective of their area of residence (rural or urban). The association between family income and OHRQoL was more pronounced among children living in rural areas.

Bacillus toyonensis BCT-7112T transient supplementation improves vaccine efficacy in ewes vaccinated against Clostridium perfringens epsilon toxin.

AIM: The aim of the present study was to examine the vaccine immune response in ewes supplemented with Bacillus toyonensis BCT-7112T during a period of 5-day supplementation before vaccination against a recombinant Clostridium perfringens epsilon toxin (rETX). METHODS AND RESULTS: Ewes were vaccinated with 200 µg of rETX adjuvanted with 10% aluminium hydroxide. The treat group was orally supplemented with B. toyonensis BCT-7112T (3 × 108 viable spores) for 5 days prior to the first and second vaccination. Ewes supplemented with B. toyonensis BCT-7112T showed higher neutralizing antibody titres than the non-supplemented ewes (P < 0·05), with an increase in serum levels for total IgG anti-rETX by 3·2-fold (P < 0·0001), and for both IgG isotypes IgG1 and IgG2 by 2·1-fold and 2·3-fold (P < 0·01), respectively, compared with the control group. The peripheral blood mononuclear cells of ewes in the supplemented group had a higher (P < 0·05) cytokine mRNA transcription levels for IL-2 (6·4-fold increase), IFN-γ (2·9-fold increase) and transcription factor Bcl6 (2·3-fold increase) compared with the control group. CONCLUSION: We conclude that a 5 days of supplementation with B. toyonensis BCT-7112T prior vaccination is sufficient to significantly improve the humoral immune response of ewes against C. perfringens recombinant ETX vaccine. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings open a new perspective in the utilization of B. toyonensis BCT-7112T as an immunomodulator since a 5 days period of probiotic supplementation is sufficient to improve the vaccine immune response.

Coleofasciculaceae, a Monophyletic Home for the Microcoleus steenstrupii Complex and Other Desiccation-tolerant Filamentous Cyanobacteria.

Cyanobacteria classified as Microcoleus steenstrupii play a significant role as pioneers of biological soil crusts (biocrusts), but this taxon is recognized to constitute a diverse complex of strains and field populations. With the aim of clarifying its systematics, we conducted a polyphasic characterization of this and allied taxa. A 16S ribosomal gene meta-analysis of published environmental sequences showed that the complex encompasses a variety of well supported genus-level clades with clade-specific environmental preferences, indicating significant niche differentiation. Fifteen strains in the M. steenstrupii complex were selected as representative of naturally occurring clades and studied using 16S rRNA gene phylogeny, morphology, and niche delineation with respect to temperature and rainfall. Bayesian phylogenetic reconstructions within a comprehensive, curated database of long 16S rRNA cyanobacterial sequences (1,000 base pairs or more) showed that they all belonged in a monophyletic, family-level clade (91.4% similarity) that included some other known genera of desiccation-resistant, largely terrestrial, filamentous, nonheterocystous cyanobacteria, including Coleofasciculus, the type genus for the family Coleofasciculaceae. To accommodate this biodiversity, we redescribe the Coleofasciculaceae, now composed of 11 genera, among which six are newly described herein (Funiculus, Parifilum, Arizonema, Crassifilum, Crustifilum, and Allocoleopsis), and five were previously recognized (Porphyrosiphon, Coleofasciculus, Pycnacronema, Potamolinea, and Wilmottia). We provide an evaluation of their respective niches and global distributions within biocrusts based on published molecular data. This new systematics treatment should help simplify and improve our understanding of the biology of terrestrial cyanobacteria.

Impact of markers of endothelial injury and hypercoagulability on systemic lupus erythematosus.

We have explored the relationship between possible hemostatic changes and clinical manifestation of the systemic lupus erythematosus (SLE) as a function of greater or lesser disease activity according to Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI-2K) criteria. Endothelial injury and hypercoagulability were investigated in patients with SLE by measuring thrombomodulin (TM), D-dimer (DDi) and thrombin generation (TG) potential. A total of 90 participants were distributed into three groups: 1) women with SLE presenting with low disease activity (laSLE) (SLEDAI-2K ≤ 4), 2) women with SLE presenting with moderate to high disease activity (mhaSLE) (SLEDAI-2K > 4), and 3) a control group comprising healthy women. Levels of TM and DDi were higher both in the laSLE and mhaSLE groups compared to controls and in mhaSLE compared to the laSLE group. With respect to TG assay, lagtime and endogen thrombin potential, low concentrations of tissue factor provided the best results for discrimination among groups. Analysis of these data allow us to conclude that TM, DDi and TG are potentially useful markers for discriminating patients with very active from those with lower active disease. Higher SLE activity may cause endothelial injury, resulting in higher TG and consequently a hypercoagulability state underlying the picture of thrombosis common in this inflammatory disease.

Dyadic Adjustment and Sexual Satisfaction in HPV Diagnosed Portuguese Women: A Longitudinal Study.

This study examined the relationship between dyadic adjustment and sexual satisfaction, in Portuguese women diagnosed with human papillomavirus (HPV), using a 1-year longitudinal design. Women were assessed at the beginning of the study (N = 209), six months after (N = 178) and twelve months later (N = 105). A better dyadic adjustment predicted more sexual satisfaction but the inverse was not observed. Younger women (< 40 years) showed greater difficulties in dyadic adjustment, while older women (> 40 years) reported lower sexual satisfaction. Findings highlight the importance of intervening with couples, using different intervention programs according to women's age.

Associations between anthropometric indicators in early life and low-grade inflammation, insulin resistance and lipid profile in adolescence.

BACKGROUND AND AIMS: The long-term relations between excessive adiposity in early childhood and unfavourable cardiometabolic profiles in later ages are not yet completely understood. We aimed to assess the associations between birth weight (BW) and BMI from 6 months to 6 years of age, with biomarkers indicative of low-grade inflammation, insulin resistance and lipid profiles in adolescence. METHODS AND RESULTS: Retrospective school-based study with 415 Portuguese adolescents (220 girls), mean age of 14.08 ± 1.6 years old. Anthropometric data from birth to 6 years old was extracted from individual child health book records. Actual weight and height were measured and BMI calculated. Participants were classified at each time point as normal weight or overweight according to WHO reference values. Biomarkers were obtained from venous blood samples. Linear regressions were used to explore the associations between the biomarkers and early life anthropometric indicators. From 2 years onwards, BMI associated positively with the inflammatory score and HOMA-IR in adolescence. Children who were overweight/obese from 2 to 6 years of age presented significantly higher inflammatory score and HOMA-IR later in adolescence. TC/HDL ratio was also positively associated with BMI from the age of 5 years onwards. The associations between BMI and cardiometabolic outcomes remained positive in adolescence, with overweight adolescents presenting a higher inflammatory score, HOMA-IR and TC/HDL than normal weight adolescents. CONCLUSION: A high BMI from an early age was consistently associated with worse inflammatory and lipid profiles and insulin resistance in adolescence. No associations were found between BW and the same studied outcomes.

Reduction of scum production in a modified UASB reactor treating domestic sewage.

The scum accumulation inside gas-solid-liquid separators (GSL) is one of the main limitations of upflow anaerobic sequencing batch (UASB) reactors during treatment of domestic sewage. Although this type of reactor can be equipped with devices that periodically remove scum, this solution has been proved to be very expensive in addition to being inefficient when discharging procedures are not correctly performed. The main goal of this study was to investigate the performance of a modified UASB reactor concept with a GSL separator which promotes continuous scum discharge to the settling compartment. Furthermore, this proposal was compared with a conventional UASB reactor which was used as control. Both reactors in demo-scale were fed with domestic wastewater and scum production was measured. The results demonstrated volumetric reduction of 50%, and 75% reduction in the mass of total solids in the modified reactor. Additionally, the amount of biogas recovered from the modified reactor was higher than the amount that the control reactor recovered. Therefore, the proposed modification has been proved to be effective, bringing new possibilities to the GSL project.

Influence of volumetric loading rate on aerobic sewage treatment for indigenous algal growth.

Many rural areas of Latin America and the Caribbean (LAC) region are economically depressed. Rural sewage treatment in most areas of LAC is deficient or non-existent. Consequently, the possibility of generating economic revenue from treated sewage is an attractive option for deprived areas of developing countries. Given its peculiar characteristics, rural sewage may be coupled with biological systems such as algae for nutrient cycling. Acceptable algae growth and nutrient elimination were obtained from rural sewage whose treatment may have fallen short of current disposal standards. In this study, aerobic systems working on an 8-month cycle at three different volumetric loading rates (Bv) were assessed in relation to the lifetime growth of three algae strains native to Ecuador. Results indicate Chlorella sp. M2 as the optimal algal strain, with the highest growth rate at Bv of 1 g COD L-1 d- 1 and a removal of organic-N (30%), PO4 3--P (87%) and NH4 +-N (95%). Concomitantly, the kinetic constants of the sewage resulted in a low biomass yield coefficient, making the proposed system highly suitable for developing countries. Finally, the proposed partial recovery stream method, combining nutrient recovery with economic resource generation, appears to contain great potential.

Bone mineral density and vertebral fractures and their relationship with pulmonary dysfunction in patients with chronic obstructive pulmonary disease.

To evaluate bone mineral density (BMD) and morphometric vertebral fractures (MVF) in chronic obstructive pulmonary disease (COPD) patients in comparison with two control groups. BMD was lower in the disease group (DG) and was associated with the worst disease severity and prognosis. The prevalence of MVF was high and greater in the DG than in the control groups. INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is associated with osteoporosis and vertebral fractures. It is still unclear whether the presence of fractures and changes in bone mineral density (BMD) are associated with disease severity and prognosis. The aim of this study was to evaluate BMD and morphometric vertebral fractures (MVF) in COPD patients in comparison with two control groups and to correlate these parameters with indices of COPD severity (VEF1 and GOLD) and prognosis (BODE). METHODS: This was a cross-sectional study in COPD patients (disease group, DG) who underwent BMD and vertebral fracture assessment (VFA). Two control groups were used: smokers without COPD (smoker group, SG) and healthy never-smoker individuals (never-smoker group, NSG). RESULTS: The DG comprised 121 patients (65 women, mean age 67.9 ± 8.6 years). Altered BMD was observed in 88.4% of the patients in the DG, which was more prevalent when compared with the control groups (p < 0.001). The BMD values were lower in the DG than in the control groups (p < 0.05). BMD was associated with the worst disease severity and prognosis (p < 0.05). The prevalence of MVF was high (57.8%) and greater than that in the SG (23.8%) and the NSG (14.8%; p < 0.001). The prevalence of fractures was not associated with disease severity and prognosis. CONCLUSIONS: COPD patients have a higher prevalence of MVF and low BMD, and the latter was associated with the severity and poor prognosis of the disease.

Longitudinal association between ideal cardiovascular health status and muscular fitness in adolescents: The LabMed Physical Activity Study.

BACKGROUND AND AIMS: Muscular fitness is an emerging predictor for cardiovascular disease mortality. The ideal cardiovascular health metrics has been inversely related to a subsequent cardiometabolic health in adulthood. However, evidence regarding muscular fitness and ideal cardiovascular health in adolescents is scarce. This study aimed to examine the longitudinal association between ideal cardiovascular health index and muscular fitness. METHODS AND RESULTS: This study cohort consisted of 331 adolescents (183 girls) from the LabMed Physical Activity Study who were followed from 2011 to 2013. Ideal cardiovascular health, as defined by the American Heart Association, was determined as meeting ideal health factors (total cholesterol, blood pressure, and glucose) and behaviors (smoking status, body mass index, physical activity, and diet). Handgrip strength and standing long jump tests assessed muscular fitness and were transformed into standardized values according to age and sex. ANCOVA showed a significant association between the accumulation of ideal cardiovascular health metrics at baseline and muscular fitness indices at follow-up (F(4, 322) = 2.280, p = 0.04). In addition, the higher the number of ideal cardiovascular health metrics accumulated, the higher the likelihood of having a high muscular fitness over a two-year period (p for trend = 0.01), after adjustments for age, sex, pubertal stage and socioeconomic status and muscular fitness at baseline. CONCLUSION: The ideal cardiovascular health status during adolescence was associated with high muscular fitness levels over a two-year period.

Fruit, vegetable consumption and blood pressure in healthy adolescents: A longitudinal analysis from the LabMed study.

BACKGROUND AND AIMS: The associations between fruit and vegetable consumption and high blood pressure among adults are well studied. Nonetheless, data on the influence of a low consumption of fruit and vegetables on cardiovascular disease risk, particularly blood pressure, among healthy adolescents are scarce. Therefore, we aim to analyse the associations between fruit and/or vegetable intake and blood pressure over a two-year period in healthy adolescents. METHODS AND RESULTS: As part of a cohort, 606 adolescents from the LabMed Physical Activity study were evaluated in 2011 (baseline) and 2013 (follow-up). Blood pressure was measured according to standardized procedures and fruit and vegetable consumption was assessed with a food frequency questionnaire. Anthropometric variables, socioeconomic status, pubertal stage and lifestyle determinants were gathered and used as confounders. Prospective associations between fruit and/or vegetable intake and blood pressure were examined using generalized linear models. Girls who consumed more fruit at baseline had a significant decrease in diastolic blood pressure at follow-up [unstandardized beta: -0.005 mmHg (95%CI: -0.01; -0.0002) (p = 0.038)]. CONCLUSION: In apparently healthy adolescents, fruit intake may already start to have an effect in blood pressure. Girls who consumed more fruit exhibited lower levels of diastolic blood pressure.

Searching for a potential antibacterial lead structure against bacterial biofilms among new naphthoquinone compounds.

AIMS: The aims of this study were to design, synthesize and to evaluate 2-hydroxy-3-phenylsulfanylmethyl-[1,4]-naphthoquinones against Gram-negative and Gram-positive bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA) and its biofilm, to probe for potential lead structures. METHODS AND RESULTS: Thirty-six new analogues were prepared with good yields using a simple, fast, operational three-procedure reaction and a thiol addition to an ο-quinone methide using microwave irradiation. All compounds were tested against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 15290, Serratia marcescens ATCC 14756, Klebsiella pneumoniae ATCC 4352, Enterobacter cloacae ATCC 23355, Enterococcus faecalis ATCC 29212, S. aureus ATCC 25923, Staphylococcus simulans ATCC 27851, Staphylococcus epidermidis ATCC 12228 and a hospital strain of MRSA. Their antibacterial activity was determined using the disc diffusion method, revealing the activity of 19 compounds, mainly against Gram-positive strains. Interestingly, the minimal inhibitory concentration ranges detected for the hit molecules (32-128 µg ml-1 ) were within Clinical and Laboratory Standards Institute levels. Promisingly, compound 15 affected the MRSA strain, with a reduction of up to 50% in biofilm formation, which is better than vancomycin as biofilm forms a barrier against the antibiotic that avoids its action. CONCLUSIONS: After probing 36 naphthoquinones for a potential antibacterial lead structure against the bacterial biofilm, we found that compound 15 should be explored further and also should be structurally modified in the near future to test against Gram-negative strains. SIGNIFICANCE AND IMPACT OF THE STUDY: Since vancomycin is one of the last treatment options currently available, and it is unable to inhibit biofilm, the research of new antimicrobials is urgent. In this context, 2-hydroxy-3-phenylsulfanylmethyl-[1,4]-naphthoquinones proved to be a promising lead structure against MRSA and bacterial biofilm.

Muscular fitness, adherence to the Southern European Atlantic Diet and cardiometabolic risk factors in adolescents.

BACKGROUND AND AIM: Muscular fitness and an adherence to the Southern European Atlantic Diet (SEADiet) have been inversely associated with cardiometabolic risk. Our aim was to assess the independent and combined associations of muscular fitness and adherence to the SEADiet on cardiometabolic risk in adolescents. METHODS AND RESULTS: A total of 467 Portuguese adolescents (275 girls) participated in this cross-sectional study. Sum of the Z-Scores of Curl-Up and Push-Up tests was used to create a muscular fitness score. Adherence to SEADiet was obtained using a food frequency questionnaire. A cardiometabolic risk score was computed from sum of Z-score of triglycerides, systolic blood pressure, total cholesterol/HDL ratio, HOMA-IR and waist circumference. Adolescents with low muscular fitness and low adherence to the SEADiet had the poorest cardiovascular profile F(5, 452) = 5.074 (p < 0.001) and the highest odds of having a high cardiometabolic risk score (OR = 4.5; 95% CI: 2.1-14) when compared to those with High muscular fitness/High adherence to the SEADiet after adjustments for age, sex, pubertal stage, socioeconomic status, total energy intake, low-energy reporter and cardiorespiratory fitness. CONCLUSIONS: Our findings seem suggest that improving muscular fitness as well as an adherence to the SEADiet could be an important strategy to reduce clustered cardiometabolic risk in youth.

Muscular fitness and metabolic and inflammatory biomarkers in adolescents: Results from LabMed Physical Activity Study.

This study aimed to evaluate the associations between muscular fitness and inflammatory biomarkers and to investigate the relationship between muscular fitness and selected clustered inflammatory biomarkers in adolescents. This is a cross-sectional analysis with 529 adolescents (267 girls) aged 12-18 years. Handgrip strength and standing long jump tests assessed MF. Continuous scores of clustered inflammatory biomarkers (sum of Z-scores of C-reactive protein [CRP], C3, C4, fibrinogen, and leptin); metabolic risk factor (MRF) score (sum of Z-scores of SBP, triglycerides, ratio total cholesterol [TC]/HDL, HOMA-IR, and waist circumference [WC]) were computed. Regression analyses showed an inverse association between muscular fitness score (ß=-.204; P<.021) and clustered score of inflammatory biomarkers, adjusted for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, cardiorespiratory fitness (CRF), MRF score, and body fat. Analysis of covariance showed that adolescents with an adverse inflammatory profile with low levels of muscular fitness exhibit the poorest MRF score (F3,525 =6.461; P<.001), adjusted for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, CRF, and body fatness. The inflammatory state seems to explain a significant part of the highest MRF score and in adolescents with high inflammatory status and low muscular strength.

Association between serum adiponectin levels and muscular fitness in Portuguese adolescents: LabMed Physical Activity Study.

BACKGROUND AND AIM: Paradoxically, recent investigations have showed that adiponectin levels are inversely associated with muscle strength. However, to date, there is a lack of knowledge on the relationship between muscular fitness (MF) and adiponectin levels in adolescents. We aimed to examine the independent associations between MF and adiponectin levels in adolescents, controlling for several potential confounders. METHODS AND RESULTS: This is a cross-sectional analysis with 529 Portuguese adolescents aged 12-18 years. A MF score was computed as the mean of the handgrip strength and standing long jump standardized values by age and gender. We measured fasting glucose, insulin, HDL-cholesterol, C-reactive protein and adiponectin. Linear regression analysis showed a significant inverse association between adiponectin (Z-score by age and sex) and MF score, after adjustments for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, body mass index, HOMA-IR, HDL-cholesterol, C-reactive protein and cardiorespiratory fitness (unstandardized ß = -0.176; p < 0.005). Analysis of covariance showed a significant difference between the Low MF/Non-overweight group and the High MF/Non-overweight Group (p < 0.05) and between the Low MF/Non-overweight and High MF/Overweight Group (p < 0.05) (F (5, 523) = 2.262, p = 0.047). CONCLUSION: Adiponectin circulating levels are inversely and independently associated with MF. In non-overweight adolescents, those with high levels of MF presented lower levels of adiponectin compared to those with Low MF. Likewise, overweight adolescents with High MF presented lower levels of serum adiponectin than non-overweight adolescents with Low MF.

Generalized Bullous Fixed Drug Eruption due to Bromhexine.

We describe a patient with a generalized bullous form of Fixed Drug Eruption (FDE) induced by bromhexine, a commonly used drug for respiratory symptoms. This is a rare association and generalized bullous FDE is also very rare. We emphasize the importance of patch tests in identifying the culprit drug.

Parental education and physical activity in pre-school children.

BACKGROUND: The purpose of this study was to objectively assess pre-school children's total physical activity (TPA) patterns and compliance with guidelines and to examine differences relative to parental education. METHODS: The sample consisted on 509 healthy pre-school children, aged 3-6 years recruited from kindergartens located in the metropolitan area of Porto, Portugal. The PA was assessed for 7 consecutive days by accelerometry. For TPA, we followed the guidelines of the National Association for Sport and Physical Education (NASPE) (children who spent at least >120 min per day in active play). For TPA, we calculated the proportion of children who spent at least >120 min per day in active play and moderate-to-vigorous physical activity (MVPA), we calculated the proportion of children who spent at least >60 min per day in active play. Parental education was analysed according to the Portuguese education system. RESULTS: Children with parents in the highest education level were less active than children from low and middle education level (P ≤ 0.001) in all patterns of PA (week and weekend). Regarding TPA during the week we found that the majority of children from low and middle parental education meet the NASPE guidelines. On the other hand, more than half the children from high parental education did not meet these recommendations (P ≤ 0.001) and MVPA recommendations (P ≤ 0.05). In both recommendations, children from low parental education were twice more likely to meet the recommendations compared with children belonging to high parental education. CONCLUSION: Parent education was negatively associated with children's daily physical activity patterns and compliance with guidelines.

Validation of otolith daily increments in early juveniles of shanny Lipophrys pholis.

To assess the periodicity of micro-increment formation in otoliths of Lipophrys pholis, 90 early juveniles were immersed in alizarin red S or tetracycline hydrochloride for 24 h and sacrificed after 10, 20 and 30 days. The number of micro-increments viewed under light microscopy was significantly related to the duration of the experimental period, and the slopes of the linear regressions were not significantly different from 1. This study indicates that micro-increments in sagittae were deposited daily and can be used as reliable sources of age information for L. pholis.

The multiple actions of dipeptidyl peptidase 4 (DPP-4) and its pharmacological inhibition on bone metabolism: a review.

BACKGROUND: Dipeptidyl peptidase 4 (DPP-4) plays a crucial role in breaking down various substrates. It also has effects on the insulin signaling pathway, contributing to insulin resistance, and involvement in inflammatory processes like obesity and type 2 diabetes mellitus. Emerging effects of DPP-4 on bone metabolism include an inverse relationship between DPP-4 activity levels and bone mineral density, along with an increased risk of fractures. MAIN BODY: The influence of DPP-4 on bone metabolism occurs through two axes. The entero-endocrine-osseous axis involves gastrointestinal substrates for DPP-4, including glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptides 1 (GLP-1) and 2 (GLP-2). Studies suggest that supraphysiological doses of exogenous GLP-2 has a significant inhibitory effect on bone resorption, however the specific mechanism by which GLP-2 influences bone metabolism remains unknown. Of these, GIP stands out for its role in bone formation. Other gastrointestinal DPP-4 substrates are pancreatic peptide YY and neuropeptide Y-both bind to the same receptors and appear to increase bone resorption and decrease bone formation. Adipokines (e.g., leptin and adiponectin) are regulated by DPP-4 and may influence bone remodeling and energy metabolism in a paracrine manner. The pancreatic-endocrine-osseous axis involves a potential link between DPP-4, bone, and energy metabolism through the receptor activator of nuclear factor kappa B ligand (RANKL), which induces DPP-4 expression in osteoclasts, leading to decreased GLP-1 levels and increased blood glucose levels. Inhibitors of DPP-4 participate in the pancreatic-endocrine-osseous axis by increasing endogenous GLP-1. In addition to their glycemic effects, DPP-4 inhibitors have the potential to decrease bone resorption, increase bone formation, and reduce the incidence of osteoporosis and fractures. Still, many questions on the interactions between DPP-4 and bone remain unanswered, particularly regarding the effects of DPP-4 inhibition on the skeleton of older individuals. CONCLUSION: The elucidation of the intricate interactions and impact of DPP-4 on bone is paramount for a proper understanding of the body's mechanisms in regulating bone homeostasis and responses to internal stimuli. This understanding bears significant implications in the investigation of conditions like osteoporosis, in which disruptions to these signaling pathways occur. Further research is essential to uncover the full extent of DPP-4's effects on bone metabolism and energy regulation, paving the way for novel therapeutic interventions targeting these pathways, particularly in older individuals.