Search

Describes a study of the effectiveness of computer-simulation programs in enhancing biology students' familiarity with ecological modeling and concepts. Finds that computer simulations improved student comprehension of ecological processes expressed in mathematical form, but did not allow a full understanding of ecological concepts. Contains 28 references. (Author/WRM)

In this paper, we studied the spatial variability of soil organic C (SOC), inorganic N (SIN) and extractable P (Pextr) in a grazed Mediterranean-type vegetation formation. Sampling was conducted from a gently sloping area in northern Greece.. The grazing pressure was evenly distributed over the experimental area with the exception of an overgrazed passage zone 200-300 m from steeper foothills. Soil samples, from the upper 10 cm, were collected every 10 m along four replicate lines (400 m length with a distance of 10 m between lines). Sampling took place twice (October and February). Data were analysed by geostatistical tools, and spherical models were significantly fitted to the semivariograms. SOC in both samplings and SIN in the first one displayed moderate spatial dependence which indicates the non-random distribution of their concentration. On the contrary, Pextr and SIN in winter exhibited weak spatial dependence, whereas Pextr in autumn showed spatial independence. For the parameters exhibiting spatial pattern, two scales of dependence were revealed: a fine scale within distances shorter than 10 m and a coarse scale varying between 80 and 130 m. The coarse distribution of SOC, SIN and Pextr invoked interplay among more predictable (composition of vegetation) and unpredictable (leaching, runoff) extrinsic factors, occurring at the landscape level. Specifically, SOC as a storage agent exhibited uniform spatial pattern in both samplings. By contrast, SIN by being susceptible to leaching exhibited time-specific dependence, whereas Pextr which was affected by surface runoff displayed limited or even spatial independence. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the Kozani - Florina basin (Northern Greece) five power stations are functioning using lignite as fuel. In this study, we assess both the indicator value of soil microbial diversity using the biolog method and the nematode abundance in relation to the flying ash deposition capacity as expressed by certain heavy metal concentrations. Soil samples were collected from fields and two forest covered sites at various distances from the stations on alluvial and Pliocene deposit, following a general direction from South to North (or vice versa). Results showed that increased values of heavy metal concentrations and low values of the biological variables appeared near the older station of Ptolemais, suggesting that the effects are correlated with chronic ash deposition. The results from the rest stations did not show a specific pattern that could be attributed to the flying ash. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in patients with cardiomyopathies and its clinical management presents a significant challenge. The prevalence of AF varies among cardiomyopathies, with hypertrophic (HCM) and dilated cardiomyopathy (DCM) associated with higher rates of AF. Presence of AF portends increased risk for thromboembolism, heart failure, and cardiovascular morbidity and mortality in patients with cardiomyopathy. The complex genetic substrate in DCM and non-dilated left ventricular cardiomyopathy (NDLVC) contribute to the heterogeneity of AF burden and its sequelae among cardiomyopathy genotypes, necessitating genotype-tailored approach in AF screening and management. Given the lack of validation of traditional risk scores for AF in cardiomyopathies, current clinical recommendations emphasize the importance of comprehensive risk stratification for AF, monitoring for AF, and early initiation of oral anticoagulation for brief AF episodes in specific cardiomyopathy subtypes such as hypertrophic or amyloid cardiomyopathy. AF management includes antiarrhythmic drugs, interventional therapies such as catheter ablation, mitral valve replacement when necessary, and lifestyle modifications to attenuate AF burden and improve quality of life. This review summarizes the current knowledge on the clinical significance, prognostic implications, and treatment of AF among different cardiomyopathy subtypes. We underscore the paradigm shift in AF management advocating for an individualized, subtype-specific, and genotype-aware approach to AF in cardiomyopathies, which is instrumental in improving prognosis and patient-centric care., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Inc. All rights reserved.)

Aims: Sudden arrhythmic death syndrome (SADS) refers to a sudden death, which remains unexplained despite comprehensive post-mortem examination and a toxicological screen. We aimed to investigate the impact of age and sex on the overall diagnostic yield and underlying aetiology in decedents with SADS using a combined approach of familial evaluation (FE) and molecular autopsy (MA)., Methods and Results: Consecutive referrals to a single centre for FE only, MA only or both, following a SADS death were included. First-degree family members underwent comprehensive FE and decedents with post-mortem DNA were sequenced with a 36 cardiac gene panel for MA. A Bayesian framework for analysis was performed to identify associations. Among 760 SADS decedents (66% male; mean age 31 ± 12 years) the overall diagnostic yield for an inherited cardiac condition was 37% (32-42%) and 9% (6-12%) for FE and MA cohorts. In a subset where both FE and MA were performed the diagnostic yield was 45% (38-61%). The relative risk of an FE diagnosis of long QT syndrome (LQTS) or Catecholaminergic polymorphic ventricular tachycardia (CPVT) vs. remaining unexplained declined by 5.6% [RR 0.94 (0.91-0.98)] and by 11% [RR 0.89 (0.81-0.97)], for each year increase in age. Females were more likely to have a diagnosis by both FE [40% (34-45%) vs. 36% (31-41%)] and MA [15% (10-21%) vs. 6% (3-8%)]. Females [8.1% (4.1-13.4%)], were more likely to be diagnosed with LQTS than males [1.2% (0.2-2.7%)] in the MA cohort., Conclusion: After a SADS death, the diagnostic yield of comprehensive FE, MA, or both in an expert setting can be up to 45% with a combined approach. Females had higher diagnostic yield than males, most notable with LQTS. CPVT and LQTS diagnoses declined with increasing age. These data highlight the relative utility of FE and MA depending on age and sex for determining underlying diagnoses following SADS deaths., Competing Interests: Conflict of interest: B.G. has participated in advisory board for Bristol Myers Squibb. J.S.W. has received research support from Bristol Myers Squibb, and has acted as a consultant for MyoKardia, Pfizer, Foresite labs, Health Lumen, and Tenaya Therapeutics. N.W. has received research funding from Novo Nordisk and has consulted for ArgoBio. M.T.E. has recieved consultancy fees from Bristol Myers Squibb and Cytokinetics. E.R.B. has acted as a consultant for Boston Scientific and Solid Biosciences. M.P. has consulted for Bristol Myers Squibb., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Introduction: Tinnitus, the perception of sound without an external auditory stimulus, affects approximately 10-15% of the population and is often associated with significant comorbidities such as headaches. These conditions can severely impact the quality of life. The aim of this study was to evaluate the efficacy of a food supplement in reducing the symptoms of both tinnitus and headache in patients experiencing these conditions concurrently., Methods: This prospective study included 32 patients (21 males and 11 females) aged between 23 and 68 years (mean age 49.38 years) who were experiencing both tinnitus and headache. The study assessed the impact of a food supplement on tinnitus and headache over a 90-day treatment period using three main instruments: the Tinnitus Handicap Inventory (THI), the Headache Impact Test (HIT-6), and a Visual Analog Scale (VAS) for discomfort. Statistical analyses, including paired t tests, were conducted to compare pre- and posttreatment scores. In the same dataset, Ridge Regression, a linear regression model with L2 regularization, was used to predict posttreatment scores (THI90, HIT90, VAS90)., Results: The results indicated a statistically significant reduction in all three measures after 90 days of treatment. The mean THI score decreased from 29.81 to 27.06 (p = 0.011), the mean HIT-6 score decreased from 50.41 to 48.75 (p = 0.019), and the mean VAS score for discomfort decreased from 7.63 to 7.13 (p = 0.033). The optimal Ridge Regression model was found with an "alpha" value of approximately 3.73. The performance metrics on the test set were as follows: Mean Squared Error (MSE) of 13.91 and an R-squared score of 0.61, indicating that the model explains approximately 61% of the variance in the posttreatment scores. These results indicate that pretreatment scores are significant predictors of posttreatment outcomes, and gender plays a notable role in predicting HIT and VAS scores posttreatment., Conclusion: This study demonstrates that a food supplement is effective in reducing the symptoms of tinnitus and headache in patients suffering from both conditions. The significant improvements in THI, HIT-6, and VAS scores indicate a positive impact on patient quality of life. Further research with larger sample sizes and more detailed subgroup analyses is recommended to fully understand the differential impacts of treatment across various demographics., (© 2024 S. Karger AG, Basel.)

Background: Global longitudinal active strain energy density (GLASED) is an innovative method for assessing myocardial function and quantifies the work performed per unit volume of the left ventricular myocardium. The GLASED, measured using MRI, is the best prognostic marker currently available. This study aimed to evaluate the feasibility of measuring the GLASED using echocardiography and to investigate potential differences in the GLASED among athletes based on age and sex., Methods: An echocardiographic study was conducted with male controls, male and female young athletes, and male and female veteran athletes. GLASED was calculated from the myocardial stress and strain., Results: The mean age (in years) of the young athletes was 21.6 for males and 21.4 for females, while the mean age of the veteran athletes was 53.5 for males and 54.2 for females. GLASED was found to be highest in young male athletes (2.40 kJ/m 3 ) and lowest in female veterans (1.96 kJ/m 3 ). Veteran males exhibited lower values (1.96 kJ/m3) than young male athletes did (P < 0.001). Young females demonstrated greater GLASED (2.28 kJ/m 3 ) than did veteran females (P < 0.01). However, no significant difference in the GLASED was observed between male and female veterans., Conclusion: Our findings demonstrated the feasibility of measuring GLASED using echocardiography. GLASED values were greater in young male athletes than in female athletes and decreased with age, suggesting possible physiological differences in their myocardium. The sex-related differences observed in GLASED values among young athletes were no longer present in veteran athletes. We postulate that measuring the GLASED may serve as a useful additional screening tool for cardiac diseases in athletes, particularly for those with borderline phenotypes of hypertrophic and dilated cardiomyopathies., (© 2024. The Author(s).)

Objective: The aim of the study was to explore the individual impact of BMI and height on LV size and geometry in a cohort of healthy athletes., Methods: From a total cohort of 1857 healthy élite athletes (21 ± 5 years, males 70%) investigated with ECG and echocardiogram, we considered three groups: Group 1 n = 50: BMI ≥ 30 and height < 1.90 m; Group 2 n = 87: height ≥ 1.95 m and BMI < 30; control Group 3 n = 243: height < 1.90 m and BMI = 20-29., Results: BSA was ≤2.3 m 2 in 52% of athletes in group 1 and 47% of athletes in group 2. Athletes in group 1 and in group 2 showed an enlarged LV end-diastolic diameter (LVEDD) (57 ± 6 vs 57 ± 4 vs 53 ± 4 mm in Group 3); 50% of athletes in group 1 and 38% of athletes in group 2 exhibited a LVEDD > 57 mm (p = 0.23). LV wall thickness was higher in group 1 (11 ± 1 vs 10 ± 2 mm in Group 2, p = 0.001). Concentric hypertrophy or concentric remodelling was found in 20% of athletes in group 1 vs 7% of athletes in group 2 (p = 0.04). Athletes of group 1 with BSA ≤ 2.3 m 2 showed lower LVEDD (53 ± 5 vs 60 ± 5 mm, p < 0.001), similar LV wall thickness (10 ± 1 vs 11 ± 1 mm, p = 0.128) and higher prevalence of concentric hypertrophy or concentric remodelling (31% vs 8%, p = 0.04) compared to those with BSA > 2.3 m 2 ., Conclusion: Athletes with high BMI have similar LV dimensions but greater wall thickness and higher prevalence of concentric remodelling compared to very tall athletes. Athletes with high BMI and large BSA have the widest LV dimensions., (Copyright © 2024 Hellenic Society of Cardiology. Published by Elsevier Inc. All rights reserved.)

Soil microbial biomass and activity strongly depend on land use, vegetation cover, climate, and soil physicochemical properties. In most cases, this dependence was assessed by one-to-one correlations while by employing network analysis, information about network robustness and the balance between stochasticity and determinism controlling connectivity, was revealed. In this study, we further elaborated on the hypothesis of Smith et al. (2021) that cropland soils depended more on climate variables and therefore are more vulnerable to climate change. We used the same dataset with that of Smith et al. (2021) that contains seasonal microbial, climate and soil variables collected from 881 soil points representing the main land uses in Europe: forests, grassland, cropland. We examined complete (both direct and indirect relationships) and incomplete networks (only direct relationships) and recorded higher robustness in the former. Partial Least Square results showed that on average more than 45% of microbial attributes' variability was predicted by climate and habitat drivers denoting medium to strong effect of habitat filtering. Network architecture slightly affected by season or land use type; it followed the core/periphery structure with positive and negative interactions and no hub nodes. Microbial attributes (biomass, activity and their ratio) mostly belong to core block together with Soil Organic Carbon (SOC), while climate and soil variables to periphery block with the exception of cropland networks, denoting the higher dependence between microbial and climate variables in these latter. All complete networks appeared robust except for cropland and forest in summer, a finding that disagrees with our initial hypothesis about cropland. Networks' connectivity was controlled stronger by stochasticity in forest than in croplands. The lack of human interventions in forest soils increase habitat homogeneity enhancing the influence of stochastic agents such as microbial unlimited dispersal and/or stochastic extinction. The increased stochasticity implies the necessity for proactive management actions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The athlete's heart (AH) defines the phenotypical changes that occur in response to chronic exercise training. Echocardiographic assessment of the AH is used to calculate LV mass (LVM) and determine chamber geometry. This is, however, interpreted using standard linear (ratiometric) scaling to body surface area (BSA) whereas allometric scaling is now widely recommended. This study (1) determined whether ratiometric scaling of LVM to BSA (LVMi ratio ) provides a size-independent index in young and veteran athletes of mixed and endurance sports (MES), and (2) calculated size-independent beta exponents for allometrically derived (LVMi allo ) to BSA and (3) describes the physiological range of LVMi allo and the classifications of LV geometry., Methods: 1373 MES athletes consisting of young (< 35 years old) (males n = 699 and females n = 127) and veteran (> 35 years old) (males n = 327 and females n = 220) were included in the study. LVMi ratio was calculated as per standard scaling and sex-specific LVMi allo were derived from the population. Cut-offs were defined and geometry was classified according to the new exponents and relative wall thickness., Results: LVMi ratio did not produce a size independent index. When tested across the age range the following indexes LVMi/BSA 0.7663 and LVMi/BSA 0.52 , for males and females respectively, were size independent (r = 0.012; P = 0.7 and r = 0.003; P = 0.920). Physiological cut-offs for LVMi allo were 135 g/(m 2 ) 0.7663 in male athletes and 121 g/(m 2 ) 0.52 in female athletes. Concentric remodelling / hypertrophy was present in 3% and 0% of young male and female athletes and 24% and 17% of veteran male and female athletes, respectively. Eccentric hypertrophy was observed in 8% and 6% of young male and female athletes and 9% and 11% of veteran male and female athletes, respectively., Conclusion: In a large cohort of young and veteran male and female MES athletes, LVMi ratio to BSA is not size independent. Sex-specific LVMi allo to BSA with LVMi/BSA 0.77 and LVMi/BSA 0.52 for male and female athletes respectively can be applied across the age-range. Population-based cut-offs of LVMi allo provided a physiological range demonstrating a predominance for normal geometry in all athlete groups with a greater percentage of concentric remodelling/hypertrophy occurring in veteran male and female athletes., (© 2024. The Author(s).)

Background: Homozygous truncating mutations located in the C-terminal region of the desmoplakin gene (DSP) are known to mainly cause Carvajal syndrome, an autosomal recessive syndromic form of arrhythmogenic cardiomyopathy with an extra-cardiac cutaneous phenotype., Case Presentation: Here we describe a female proband with a documented arrhythmogenic left ventricular cardiomyopathy and a syncopal episode at the age of 13, who was found homozygous for the novel DSP variant: NM&#95;004415.4:c.8586delC, p.(Ser2863Hisfs*20) at the extreme C-terminal region of the protein, just 8 amino acids upstream the stop codon. She did not have any of the typical dermatological symptoms that characterize Carvajal syndrome. Her brother had died suddenly at the age of 18 during exercise and was found homozygous for the same variant at the post-mortem, while their parents were heterozygous. The region of origin of both parents was the same geographic area of Greece, but they were not aware of any common ancestor. Detailed clinical examination revealed that the mother displayed a mild arrhythmic phenotype, while the father was asymptomatic., Conclusion: These observations pinpoint to a significant functional role of the extreme C-terminal tail of the protein., (© 2023. The Author(s).)

Objective: Transthyretin cardiac amyloidosis (ATTR-CA) is a rare and potentially fatal disease caused by the accumulation of insoluble transthyretin (TTR) amyloid fibrils in the heart. The symptoms of ATTR-CA are often non-specific, often leading to underdiagnosis. Early diagnosis and treatment have a significant impact on disease progression and mortality., Case Presentation: In this case we report a 73-year-old male presented with dyspnea on exertion. The patient had a medical history of peripheral neuropathy, bilateral carpal tunnel syndrome, spinal fusion, and a family history of coronary artery disease. Upon his presentation at the Cardiology department, cardiac echo study revealed left and right ventricular hypertrophy with pulmonary hypertension, diastolic dysfunction and a restrictive pattern. Because of the high probability of amyloidosis, the patient underwent a technetium-99m-3,3-diphosphono-1,2-propanodicarboxylic acid ( 99m Tc-DPD) bone scintigraphic study, which confirmed the diagnosis of ATTR-CA. Transthyretin gene sequencing analysis revealed the rare p. Pro24Ser pathogenic variant. Final diagnosis was ATTR-CA associated with the proline replaced by serine at position 24 (Pro24Ser) TTR variant, which is rare and only a few cases have been reported worldwide. The patient was treated with tafamidis and inotersen and followed up., Conclusion: This case highlights the importance of considering amyloidosis as a differential diagnosis for non-specific symptoms and the need for early diagnosis and management of ATTR-CA.

Hypertrophic cardiomyopathy (HCM) is a common cause of sudden cardiac death in athletes. Cardiac Magnetic Resonance (CMR) imaging is considered an excellent tool to differentiate between HCM and athlete's heart. The aim of this systematic review was to highlight the novel CMR-derived parameters with significant discriminative capacity between the two conditions. A systematic search in the MEDLINE, EMBASE and Cochrane Reviews databases was performed. Eligible studies were considered the ones comparing novel CMR-derived parameters on athletes and HCM patients. Therefore, studies that only examined Cine-derived volumetric parameters were excluded. Particular attention was given to binary classification results from multi-variate regression models and ROC curve analyses. Bias assessment was performed with the Quality Assessment on Diagnostic Accuracy Studies. Five (5) studies were included in the systematic review, with a total of 284 athletes and 373 HCM patients. Several novel indices displayed discriminatory potential, such as native T1 mapping and T2 values, LV global longitudinal strain, late gadolinium enhancement and whole-LV fractal dimension. Diffusion tensor imaging enabled quantification of the secondary eigenvalue angle and fractional anisotropy in one study, which also proved capable of reliably detecting HCM in a mixed athlete/patient sample. Several novel CMR-derived parameters, most of which are currently under development, show promising results in discerning between athlete's heart and HCM. Prospective studies examining the discriminatory capacity of all promising modalities side-by-side will yield definitive answers on their relative importance; diagnostic models can incorporate the best performing variables for optimal results.

We briefly present a case series of six patients hospitalized in the Department of Psychiatry, University General Hospital of Ioannina, between the first (starting March 23, 2020) and the second (starting November 7, 2020) lockdown in Greece who presented with COVID-19 - related delusional ideas. All patients had negative PCR prior to admission and no history of COVID-19 infection.The first three of our cases were admitted during the first lockdown, between March 23 and May 4, one involuntary and the other two voluntary. The first one was diagnosed with acute and transient psychosis (F23 - First Episode Psychosis) and the other two with psychotic depression (F32.3). Three additional patients were admitted voluntary after the end of the first lockdown. One was diagnosed with acute and transient psychosis (F23-First Episode Psychosis) and the other two were relapses of a known psychiatric disorder (Bipolar disorder F31.5 and Psychotic depression F32.3). At follow-up six months after discharge all patients were in remission following antipsychotic medication, among other medicines. These cases reveal that COVID-19 pandemic may have an impact on the delusional content of new or preexisting psychotic disorders during the COVID-19 pandemic.

To describe the overlap between structural abnormalities typical of arrhythmogenic right ventricular cardiomyopathy (ARVC) and physiological right ventricular adaptation to exercise and differentiate between pathologic and physiologic findings using CMR. We compared CMR studies of 43 patients (mean age 49 ± 17 years, 49% males, 32 genotyped) with a definitive diagnosis of ARVC with 97 (mean age 45 ± 16 years, 61% males) healthy athletes. CMR was abnormal in 37 (86%) patients with ARVC, but only 23 (53%) fulfilled a major or minor CMR criterion according to the TFC. 7/20 patients who did not fulfil any CMR TFC showed pathological finding (RV RWMA and fibrosis in the LV or LV RWMA). RV was affected in isolation in 17 (39%) patients and 18 (42%) patients showed biventricular involvement. Common RV abnormalities included RWMA (n = 34; 79%), RV dilatation (n = 18; 42%), RV systolic dysfunction (≤ 45%) (n = 17; 40%) and RV LGE (n = 13; 30%). The predominant LV abnormality was LGE (n = 20; 47%). 22/32 (69%) patients exhibited a pathogenic variant: PKP2 (n = 17, 53%), DSP (n = 4, 13%) and DSC2 (n = 1, 3%). Sixteen (16%) athletes exceeded TFC cut-off values for RV volumes. None of the athletes exceeded a RV/LV end-diastolic volume ratio > 1.2, nor fulfilled TFC for impaired RV ejection fraction. The majority (86%) of ARVC patients demonstrate CMR abnormalities suggestive of cardiomyopathy but only 53% fulfil at least one of the CMR TFC. LV involvement is found in 50% cases. In athletes, an RV/LV end-diastolic volume ratio > 1.2 and impaired RV function (RVEF ≤ 45%) are strong predictors of pathology., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Physiological cardiac remodelling in highly trained athletes may overlap with dilated cardiomyopathy (DCM)., Objectives: The aim of this study was to investigate the role of the electrocardiogram (ECG) in differentiating between physiological and pathological remodelling., Methods: The study population consisted of 30 patients with DCM who revealed a pathogenic variant at genetic testing and 30 elite athletes with significant cardiac remodelling defined by a left ventricular (LV) end-diastolic diameter >62 mm and/or LV ejection fraction between 45% and 50%., Results: The ECG was abnormal in 22 (73%) patients with DCM. The most common abnormalities were low voltages (n = 14, 47%), lateral T-wave inversion (TWI) (n = 6, 20%), ventricular ectopic beats (n = 5, 17%) and anterior TWI (n = 4, 13). Two athletes revealed an abnormal ECG: complete left bundle branch block (LBBB) in one case and atrial flutter in the other. The sensitivity, specificity and accuracy of the ECG in differentiating DCM from physiological adaptation to exercise in athletes was 73% (confidence interval [CI]: 54%-88%), 93% (CI: 78%-99%) and 0.83 (CI: 0.71-0.92) respectively., Conclusions: While the ECG is usually normal in athletes exhibiting significant LV dilatation and/or systolic dysfunction, this test is often abnormal in patients with DCM harbouring a pathogenic variant. Low voltages in the limb leads and lateral TWI are the most common abnormalities., (© 2022 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.)