Intra-specific Variation
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BACKGROUND: Schistosoma mansoni was introduced from Africa to the Americas during the transatlantic slave trade and remains a major public health problem in parts of South America and the Caribbean. This study presents a comprehensive comparative analysis of three S. mansoni strains with different geographical origins-from Liberia, Belo Horizonte and Puerto Rico. We demonstrated significant variation in virulence and host-parasite interactions. METHODS: We investigated the phenotypic characteristics of the parasite and its eggs, as well as the immunopathologic effects on laboratory mouse organ systems. RESULTS: Our results show significant differences in worm morphology, worm burden, egg size, and pathologic organ changes between these strains. The Puerto Rican strain showed the highest virulence, as evidenced by marked liver and spleen changes and advanced liver fibrosis indicated by increased collagen content. In contrast, the strains from Liberia and Belo Horizonte had a less pathogenic profile with less liver fibrosis. We found further variations in granuloma formation, cytokine expression and T-cell dynamics, indicating different immune responses. CONCLUSION: Our study emphasizes the importance of considering intra-specific variations of S. mansoni for the development of targeted therapies and public health strategies. The different virulence patterns, host immune responses and organ pathologies observed in these strains provide important insights for future research and could inform region-specific interventions for schistosomiasis control.
- MeSH
- cytokiny metabolismus MeSH
- interakce hostitele a parazita MeSH
- játra * parazitologie patologie MeSH
- myši MeSH
- Schistosoma mansoni * patogenita genetika imunologie MeSH
- schistosomiasis mansoni * parazitologie imunologie patologie MeSH
- slezina parazitologie patologie imunologie MeSH
- virulence MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Libérie MeSH
- Portoriko MeSH
BACKGROUND: Variations observed in biomechanical studies might be attributed to errors made by operators during the construction of musculoskeletal models, rather than being solely attributed to patient-specific geometry. RESEARCH QUESTION: What is the impact of operator errors on the construction of musculoskeletal models, and how does it affect the estimation of muscle moment arms and hip joint reaction forces? METHODS: Thirteen independent operators participated in defining the muscle model, while a single operator performed 13 repetitions to define the muscle model based on 3D bone geometry. For each model, the muscle moment arms relative to the hip joint center of rotation was evaluated. Additionally, the hip joint reaction force during one-legged stance was assessed using static inverse optimization. RESULTS: The results indicated high levels of consistency, as evidenced by the intra- rater and inter-rater agreement measured by the Intraclass Correlation Coefficient (ICC), which yielded values of 0.95 and 0.99, respectively. However, the estimated muscle moment arms exhibited an error of up to 16 mm compared to the reference musculoskeletal model. It was found that muscles attached to prominent anatomical landmarks were specified with greater accuracy than those attached over larger areas. Furthermore, the variability in estimated moment arms contributed to variations of up to 12% in the hip joint reaction forces. SIGNIFICANCE: Both moment arm and muscle force demonstrated significantly lower variability when assessed by a single operator, suggesting the preference for employing a single operator in the creation of musculoskeletal models for clinical biomechanical studies.
- MeSH
- biologické modely MeSH
- biomechanika MeSH
- kosterní svaly * fyziologie MeSH
- kyčelní kloub * fyziologie MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Assessing changes in plant functional traits along gradients is useful for understanding the assembly of communities and their response to global and local environmental drivers. However, these changes may reflect the effects of species composition (i.e. composition turnover), species abundance (i.e. species interaction), and intra-specific trait variability (i.e. species plasticity). In order to determine the relevance of the latter, trait variation can be assessed under minimal effects of composition turnover. Nine sampling sites were established along an altitudinal gradient in a Mediterranean high mountain grassland community with low composition turnover (Madrid, Spain; 1940 m-2419 m). Nine functional traits were also measured for ten individuals of around ten plant species at each site, for a total of eleven species across all sites. The relative importance of different sources of variability (within/between site and intra-/inter-specific functional diversity) and trait variation at species and community level along the considered gradients were explored. We found a weak individual species response to altitude and other environmental variables although in some cases, individuals were smaller and leaves were thicker at higher elevations. This lack of species response was most likely due to greater within- than between-site species variation. At the community level, inter-specific functional diversity was generally greater than the intra-specific component except for traits linked to leaf element content (leaf carbon content, leaf nitrogen content, δ13C and δ15N). Inter-specific functional diversity decreased with lower altitude for four leaf traits (specific leaf area, leaf dry matter content, δ13C and δ15N), suggesting trait convergence between species at lower elevations, where water shortage may have a stronger environmental filtering effect than colder temperatures at higher altitudes. Our results suggest that, within a vegetation type encompassing various environmental gradients, both, changes in species abundance and intra-specific trait variability adjust for the community functional response to environmental changes.
- MeSH
- biodiverzita * MeSH
- druhová specificita MeSH
- ekosystém MeSH
- genetická variace MeSH
- interakce genů a prostředí * MeSH
- nadmořská výška MeSH
- pastviny * MeSH
- podnebí MeSH
- rostlinné geny MeSH
- rostliny genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Středomoří MeSH
In order to assess the DNA sequence variation and phylogenetic relationship among five tuna species (Auxis thazard, Euthynnus affinis, Katsuwonus pelamis, Thunnus tonggol, and T. albacares) out of all four tuna genera, partial sequences of the mitochondrial DNA (mtDNA) D-loop region were analyzed. The estimate of intra-specific sequence variation in studied species was low, ranging from 0.027 to 0.080 [Kimura's two parameter distance (K2P)], whereas values of inter-specific variation ranged from 0.049 to 0.491. The longtail tuna (T. tonggol) and yellowfin tuna (T. albacares) were found to share a close relationship (K2P = 0.049) while skipjack tuna (K. pelamis) was most divergent studied species. Phylogenetic analysis using Maximum-Likelihood (ML) and Neighbor-Joining (NJ) methods supported the monophyletic origin of Thunnus species. Similarly, phylogeny of Auxis and Euthynnus species substantiate the monophyly. However, results showed a distinct origin of K. pelamis from genus Thunnus as well as Auxis and Euthynnus. Thus, the mtDNA D-loop region sequence data supports the polyphyletic origin of tuna species.
- MeSH
- fylogeneze * MeSH
- genetická variace * MeSH
- konformace nukleové kyseliny * MeSH
- mitochondriální DNA chemie genetika MeSH
- pravděpodobnostní funkce MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA metody MeSH
- tuňák genetika MeSH
- zeměpis MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Variation in xylem vessel diameter is one of the most important parameters when evaluating plant water relations. This review provides a synthesis of the ecophysiological implications of variation in lumen diameter together with a summary of our current understanding of vessel development and its endogenous regulation. We analyzed inter-specific variation of the mean hydraulic vessel diameter (Dv ) across biomes, intra-specific variation of Dv under natural and controlled conditions, and intra-plant variation. We found that the Dv measured in young branches tends to stay below 30 µm in regions experiencing winter frost, whereas it is highly variable in the tropical rainforest. Within a plant, the widest vessels are often found in the trunk and in large roots; smaller diameters have been reported for leaves and small lateral roots. Dv varies in response to environmental factors and is not only a function of plant size. Despite the wealth of data on vessel diameter variation, the regulation of diameter is poorly understood. Polar auxin transport through the vascular cambium is a key regulator linking foliar and xylem development. Limited evidence suggests that auxin transport is also a determinant of vessel diameter. The role of auxin in cell expansion and in establishing longitudinal continuity during secondary growth deserve further study.
Parasites of the genus Leishmania (Kinetoplastida: Trypanosomatidae) cause widespread and devastating human diseases. Visceral leishmaniasis due to Leishmania donovani is endemic in Ethiopia where it has also been responsible for major epidemics. The presence of hybrid genotypes has been widely reported in surveys of natural populations, genetic variation reported in a number of Leishmania species, and the extant capacity for genetic exchange demonstrated in laboratory experiments. However, patterns of recombination and the evolutionary history of admixture that produced these hybrid populations remain unclear. Here, we use whole-genome sequence data to investigate Ethiopian L. donovani isolates previously characterized as hybrids by microsatellite and multi-locus sequencing. To date there is only one previous study on a natural population of Leishmania hybrids based on whole-genome sequences. We propose that these hybrids originate from recombination between two different lineages of Ethiopian L. donovani occurring in the same region. Patterns of inheritance are more complex than previously reported with multiple, apparently independent, origins from similar parents that include backcrossing with parental types. Analysis indicates that hybrids are representative of at least three different histories. Furthermore, isolates were highly polysomic at the level of chromosomes with differences between parasites recovered from a recrudescent infection from a previously treated individual. The results demonstrate that recombination is a significant feature of natural populations and contributes to the growing body of data that shows how recombination, and gene flow, shape natural populations of Leishmania.
- MeSH
- chiméra * MeSH
- genotyp MeSH
- Leishmania donovani genetika MeSH
- leishmanióza viscerální parazitologie MeSH
- lidé MeSH
- rekombinace genetická MeSH
- sekvenování celého genomu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Etiopie MeSH
RATIONALE, AIMS AND OBJECTIVES: To evaluate obstetricians' inter- and intra-observer agreement on intrapartum cardiotocogram (CTG) recordings and to examine obstetricians' evaluations with respect to umbilical artery pH and base deficit. METHODS: Nine experienced obstetricians annotated 634 intrapartum CTG recordings. The evaluation of each recording was divided into four steps: evaluation of two 30-minute windows in the first stage of labour, evaluation of one window in the second stage of labour and labour outcome prediction. The complete set of evaluations used for this experiment is available online. The inter- and intra-observer agreement was evaluated using proportion of agreement and kappa coefficient. Clinicians' sensitivity and specificity was computed with respect to umbilical artery pH, base deficit and to Apgar score at the fifth minute. RESULTS: The overall proportion of agreement between clinicians reached 48% with 95% confidence intervals (CI) (CI: 47-50). Regarding the different classes, proportion of agreement ranged from 57% (CI: 54-60) for normal to 41% (CI: 36-46) for pathological class. The sensitivity of clinicians' majority vote to objective outcome was 39% (CI: 16-63) for the umbilical artery base deficit and 27% (CI: 16-42) for pH. The specificity was 89% (CI: 86-92) for both types of objective outcome. CONCLUSIONS: The reported inter-/intra-observer variability is large and this holds irrespective of clinicians' experience or work place. The results support the need of modernized guidelines for CTG evaluation and/or objectivization and repeatability by introduction of a computerized approach that could standardize the process of CTG evaluation within the delivery ward.
- MeSH
- kardiotokografie statistika a číselné údaje MeSH
- klinické kompetence * MeSH
- koncentrace vodíkových iontů MeSH
- lidé MeSH
- odchylka pozorovatele MeSH
- porodnictví statistika a číselné údaje MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- software MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PURPOSE: To assess the diagnostic performance of the skinfold (SKF) method to detect obesity in patients enrolled in an outpatient cardiac rehabilitation (CR) program. METHODS: This study involves outpatients attending a phase II CR program who underwent air displacement plethysmography (ADP) to assess body composition. We measured body fat percentage (BF%), using a 3-site SKF method calculated through the Jackson-Pollock equation utilizing a Harpenden caliper. Air displacement plethysmography calculated BF% using a bicompartmental model, deriving the body composition after the direct calculation of body density (BD), using the Siri equation [(BF% = 495/BD) - 450]. We calculated the diagnostic performance of SKF to detect obesity, utilizing a BF% cutoff of ≥35% for women and ≥25% for men determined by SKF and ADP to define obesity. RESULTS: Our sample (n = 310) was 80% men, 60.2 ± 11 years of age, had a mean weight of 89.88 ± 17.96 kg, height 173.38 ± 8.68 cm, body mass index (BMI) 29.78 ± 5.01 kg/m, waist circumference 100.55 ± 14.38 cm, and waist-to-hip ratio of 0.96 ± 0.09. The evaluation of the diagnostic performance of SKF to detect obesity showed a sensitivity of 57%, specificity of 93%, a positive predictive value of 97%, and a negative predictive value of 33%. These values were not different from the diagnostic performance of BMI to detect obesity as defined by BF%. SKF and BMI misclassified 43% and 49% of obese patients as nonobese, respectively. CONCLUSION: Our findings underscore the limitation of using SKF to assess body fatness in the CR setting.
- MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci srdce komplikace rehabilitace MeSH
- obezita komplikace diagnóza MeSH
- odchylka pozorovatele MeSH
- pletysmografie metody MeSH
- průřezové studie MeSH
- retrospektivní studie MeSH
- senioři MeSH
- senzitivita a specificita MeSH
- tloušťka kožní řasy * MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
