Contraction Pattern Research Articles

Apical rocking and septal flash revealed by an electrocardiographic parameter in the left bundle branch block

Abstract Background Assessing the relationship between electrical and mechanical dyssynchrony in patients with left bundle branch block (LBBB) remains a significant challenge for clinicians. Visual echocardiographic parameters, apical rocking (ApR), and septal flash (SF) are accurate markers of the contraction-and-stretch pattern in the septal and lateral wall in LBBB patients. Electrical activity of the LV apical septum and the LV lateral wall is ECG recorded by the aVL and aVF leads. An ECG parameter that integrates the electrical activation of these two contralateral LV walls could reveal subtle electrical features related to the uncoordinated contraction pattern in LBBB. To the best of our knowledge, no studies have examined the relationship between electrical and mechanical uncoordinated activation of the apical septum and lateral LV wall. Purpose This study aimed to assess the relationship between visual echocardiographic parameters of mechanical uncoordinated contraction pattern (ApR and SF) and ECG parameters of electrical intraventricular asynchrony in patients with LBBB. Methods We retrospectively included 157 consecutive patients with LBBB, in sinus rhythm, without significant coronary artery disease, and no more than mild organic valvular heart disease. The ApR and SF were echocardiographic visually assessed as a typical sequence of the septal-to-lateral apex motion for the ApR and the short leftward movement of the septum in early systole for the SF. We measured the following ECG parameters: LV activation times (LVAT), RR1 interval (as the longest interval from the first R wave to the last R1 wave) in lateral leads, intrinsicoid deflection (ID) in lateral and aVF leads, and a newly defined marker – the difference (Diff) between aVL and aVF ID’s (Diff_IDaVL_aVF). Based on the presence and absence of both ApR and SF (ApR_SF), the patients were divided into two groups: patients with (68.2%) and without (31.8%) ApR_SF. Results In the group of patients with ApR_SF, the LVAT, ID, and RR1 measured in lateral leads, and the Diff_IDaVL_aVF were significantly longer, but IDaVF was significantly shorter compared to the group of patients without ApR_SF (p<0.05) (Table 1). In multivariable analysis, the Diff_IDaVL_aVF (p < 0.001) was the only parameter independently correlated with the presence of ApR_SF (Table 2). On ROC analysis, the best cut-off of DIFF_IDaVL_IDaVF for predicting the presence of ApR_SF in LBBB patients was 46 ms (AUC of 0.92, sensitivity 86%, and specificity 80%) (Figure 2). Conclusions In LBBB, a simple ECG parameter incorporating the electrical activation of contralateral LV myocardial segments can provide insights into the myocardial contraction pattern in LBBB patients. A Diff_IDaVL_aVF longer than 46 msec identified LBBB patients with specific contraction patterns (ApR_SF). Considering ECG is the screening tool for LBBB diagnosis, these patients might benefit from early treatment to avoid a worse prognosis.

Atrial strain assessment in elite athletes: unveiling physiologic adaptation

Abstract Background Left atrial (LA) strain, measured by speckle-tracking echocardiography, provides insights into cardiac function beyond traditional volumetric assessments. In athletes, the effects of chronic exercise on LA strain are unclear, with conflicting findings on whether it reflects physiological adaptation or potential dysfunction. Aims This study aimed to comprehensively assess LA remodeling and function in professional soccer players compared to controls. We hypothesized that while athletes would exhibit LA enlargement, their atrial function would remain preserved due to the physiological nature of cardiac remodeling in this population. Methods A retrospective analysis of echocardiographic parameters, namely left atrial strain, was carried out in a group of professional male athletes compared to a control group of healthy male individuals. A GE Vivid E95 echocardiographic ultrasound system and EchoPAC V.206 software (GE Vingmed Ultrasound AS, Horten, Norway) were used. Shapiro-Wilk test was used to test data distribution, ANOVA and t-test were used as a parametric tests, and Man-Whitney as a non-parametric Test (SPSS v.27). Results The study analyzed 111 athletes with a median age of 24 (21-31) years and 70 healthy male individuals from the control group with a median age of 27 (23-32) years. Athletes had a significantly higher indexed left atrial end-systolic volume compared to the control group (41 ± 9 ml/m² vs. 31 ± 7 ml/m², p<0.001). Despite the difference in volume, the early and late diastolic tissue velocities were similar in both groups and E/E’ was lower (4.4 ± 0.9 vs. 5.0 (4.5-5.8), p<0.001). There were no significant differences between athletes and the control group in Left Atrial Reservoir Strain (LASr) and Left Atrial Conduit Strain (LAScd). The active contraction of the left atrium during atrial systole is reduced in athletes, which had a significantly lower left atrial contraction strain compared to the control group (-9 (-11 – -8)% vs. -12 ± 4%, p<0.001). Conclusion The data suggests that athletes' hearts have undergone specific adaptations, particularly in terms of increased left atrial size and altered contraction patterns. Maintaining atrial reservoir strain (the most validated parameter for normality) and atrial conduit strain within normal ranges may indicate that morphological changes are merely normal adaptations to the high cardiac output demands during exercise. Descriptive analysis LA strain example

An invasive pathogen generally contracts species to their niche cores, not margins

Quantifying how species' distributions contract in response to threats can reveal pathways of decline and the role of environmental conditions in moderating threat impacts. Two general patterns of niche contraction have been described: ecological marginalization, where species contract away from threat impacts to peripheral, sub‐optimal areas of their niche, and; contraction to the core, where species contract toward their niche center where their fitness and capacity to withstand threat impacts is highest. Recent work has described widespread ecological marginalization in declining mammal species, for which land use change and overexploitation are key threats. Different threatening processes could result in contrasting patterns of niche contraction, although this has not been well‐studied. Here, we examine patterns of realized niche contraction in Australian frog species impacted by the emergence of chytrid fungus Batrachochytrium dendrobatidis, a pathogen that has driven catastrophic amphibian declines globally. We quantified changes in species' environmental niche space following chytrid emergence and documented a pattern of contraction toward the niche core in declining species. We develop and apply a novel approach to show that these niche contractions are driven by losses in a subset of niche space, suggesting population extinctions due to chytrid are driven by factors shaping both pathogen fitness (threat impact) and host fitness (threat tolerance). Species declines have been concentrated in high elevation areas with cooler temperatures, which are more physiologically suitable for the pathogen and constrain the resilience of frog hosts at both individual and population levels. Given the contrast between our results and widespread ecological marginalization in mammals, we propose that while a given threat may result in common patterns of decline among affected species, patterns of decline may vary considerably between threatening processes and among taxa.

Distinct detection and discrimination sensitivities in visual processing of real versus unreal optic flow.

We examined the intricate mechanisms underlying visual processing of complex motion stimuli by measuring the detection sensitivity to contraction and expansion patterns and the discrimination sensitivityto the location of the center of motion (CoM) in various real and unreal optic flow stimuli. We conducted two experiments (N = 20 each) and compared responses to both "real" optic flow stimuli containing information about self-movement in a three-dimensional scene and "unreal" optic flow stimuli lacking such information. We found that detection sensitivity to contraction surpassed that to expansion patterns for unreal optic flow stimuli, whereas this trend was reversed for real optic flow stimuli. Furthermore, while discrimination sensitivity to the CoM location was not affected by stimulus duration for unreal optic flow stimuli, it showed a significant improvement when stimulus duration increased from 100 to 400 ms for real optic flow stimuli. These findings provide compelling evidence that the visual system employs distinct processing approaches for real versus unreal optic flow even when they are perfectly matched for two-dimensional global features and local motion signals. These differences reveal influences of self-movement in natural environments, enabling the visual system to uniquely process stimuli with significant survival implications.

Muscle activity mapping by single peak localization from HDsEMG.

Human-machine interfaces using electromyography (EMG) offer promising applications in control of prosthetic limbs, rehabilitation assessment, and assistive technologies. These applications rely on advanced algorithms that decode the activation patterns of muscles contractions. This paper presents a new approach to assess and decode muscle activity by localizing the origin of individual temporal peaks in high-density surface EMG recordings from the dorsal forearm during low force finger extensions. Localization was performed using a surface Gaussian fit applied in the spatial domain to the varying amplitudes across the channels of the electrode grids. Localized EMG peaks were used to estimate different muscle volumes for each finger, showing high consistency across 10 subjects. The results suggest that muscle regions generating each action are highly distinct and indicate potential structural differences of muscle fibres between digits. The estimated volumes were further used to classify individual EMG peaks into each corresponding action. The percentage of correctly classified peaks for each action across 10 participants were 79±18, 84±9, 76±13, and 79±9 percent for index, middle, ring, and little finger extension, respectively. The presented volume analysis provides a new approach to assessing the spatial activation patterns in compact muscle anatomies; and the single peak classification approach opens up possibilities for near-instantaneous identification of muscle activations.

Anthropogenic Pressures Lead to Different Patterns of Niche Contraction and Protected Area Cover in Three Species Procapra Gazelles on Qinghai‐Tibet Plateau and Mongolia

ABSTRACTAimAnthropogenic threats often lead to range contraction towards the margins of a species historic niche, resulting in increased extinction risk. Here, we investigate niche characteristics of current and historic populations to evaluate changes in ‘Area of Niche’ (AON) following range loss from different levels of anthropogenic threats three congeneric Asian gazelle species are facing: Przewalski's (Procapra przewalskii), Tibetan (P. picticaudata) and Mongolian gazelles (P. gutturosa).LocationTibet, Qinghai and Mongolia.MethodsWe collated range maps for historic and contemporary distributions of Przewalski's, Tibetan and Mongolian gazelles and created 3‐dimensional hypervolume and convex hull niche models using environmental variables from the Worldclim dataset (v2) together with topographic information from SRTM elevation data from historic and contemporary Area of Habitat maps and evaluated changes over time. We calculated Area of Niche (AON) maps by projecting a scaled Mahalanobis distance from the historic niche centroid of each grid cell onto each species' historic range. Finally, we evaluated how the protected area network overlaps with historic niche characteristics.ResultsThe endangered Przewalski's gazelle has lost almost all its range and niche, with remaining populations at niche peripheries. In contrast, the near‐threatened Tibetan and least‐concern Mongolian gazelles have lost less range and niche and contracted towards their historic niche centre. Protected areas for each species were biased towards the ecological margins of their historic ranges, which can result in sub‐optimal conservation strategies.Main ConclusionsThis study uses niche modelling to evaluate changes in Area of Niche (AON) occupied by a species that has undergone range contraction. We highlight that species most affected by anthropogenic threats are most vulnerable to niche shift and contraction. These species are also vulnerable to a mismatch between the protected area network and species historic niche space. We advocate that conservation strategies should include niche dynamics as an indicator of the species risk.

Rethinking Paradoxical Bulging of the Masseter Muscle Following Botulinum Toxin Injection: An Ultrasound Evaluation

Abstract Background Paradoxical bulging of the masseter (PMB) is an uncommon complication following treatment with botulinum neurotoxin-A (BoNT-A). This is currently believed to be caused by uneven distribution of BoNT-A within masseter, resulting in stronger, compensatory, contraction of the superficial head relative to its deeper heads. Objectives To visualize under ultrasound which part of the masseter muscle is chiefly responsible for PMB, and to propose a framework for assessment and prevention of the complication. Methods A case series of 6 patients presenting with PMB were identified in the practice of two experienced doctors over 24 months. Case notes, photographs and videos were reviewed along with static and dynamic ultrasound examinations to assess masseter architecture and patterns of contraction. Results In 7 of 8 affected masseter muscles, PMB was associated with retained movement of a deeper portion of the masseter bulging superficially during contraction. In all cases, the bulge appeared to originate from anterior or posterior compartments of the muscle. This supports the concept that masseter contraction can be classified functionally by anterior or posterior compartments, rather than anatomically by the traditional superficial, deep and intermediate heads. Conclusions Paradoxical muscle bulging of the masseter may originate from the deeper portion of the muscle bulging superficially. In addition, we propose that masseters can be considered functionally as having anterior and posterior functional units. This classification may enable clinical and ultrasound pre-assessment for anterior or posterior dominance, and for the injection technique to be adjusted to minimize the risk of PMB.

“The dynamics of IP contract patterns in the German biotechnology industry – a mixed-methods approach”

Academic spin-offs play a pivotal role in leveraging the economic potential of scientific discoveries by transferring research results into marketable technologies, products, and services. The creation of a spin-off is frequently formalized through an intellectual property (IP) contract between the research institution and the new venture, which establishes the foundation for the spin-off’s initial growth. While the broad impact of research institutions on IP contract patterns is acknowledged, further investigation is required to ascertain the specific effects of their individual preferences. Furthermore, country-specific characteristics influence technology transfer practices. However, the lack of empirical data on IP contract patterns in research-intensive nations, such as Germany, impedes a comprehensive analysis. This study examines the impact of the individual risk and reward assessments of German public research institutions on the design of IP contract patterns. A sequential mixed-methods approach is employed, starting with a survey of biotechnology spin-offs to collect empirical data on IP contract patterns. This is complemented by semi-structured expert interviews with technology transfer managers to triangulate the survey data and gain insights from the perspective of the research institutions. Our findings suggest that the observed heterogeneity in IP contract patterns can be attributed to the varying risk and reward assessments of research institutions. The resource-based view allows us to demonstrate that these variations arise from institutional preferences regarding the transfer of IP ownership versus licensing IP to spin-offs and accepting spin-off equity and/or cash compensation. The resource-based considerations in question vary between universities and non-university research institutions and are shaped by the individual IP strategies and resource endowments of each.

What makes labor difficult? Predictors and features of difficult labor in women’s and midwives’ perspective

Abstract Aim. The aim of this study was to identify what are the features of ‘difficult labor’ in the perspective of women giving birth and midwives providing care. Material and methods. Cross-section, preliminary study based on the analysis of the labor observation form and level of labor difficulty assessment form designed for the purpose of this study and fi lled in by the midwives participating in the study. The participants were 31 midwives working on the labor unit in one of the hospitals in Warsaw, Poland and 152 women who gave birth. Results. Women who had epidural, larger babies and a negative attitude towards birth and a prolonged fi rst stage of labor, were more likely to assess their labor as difficult. Among midwives labors with a longer second stage, abnormal uterine contraction patterns, and prolonged latent phase and fi rst stage of labor were assessed as more difficult. Conclusions. Some labors, despite being classified as physiological, require more effort on the part of both the midwife and woman giving birth and end with a higher level of fatigue for both. Predictors of difficult labor should be used by healthcare personnel as a guidance to help identify women at risk of negative labor experiences.

Effect of Ankle-Foot Orthosis on Paretic Gastrocnemius and Tibialis Anterior Muscle Contraction of Stroke Survivors During Walking: A Pilot Study.

Ankle-foot orthoses (AFOs) have been commonly prescribed for stroke survivors with foot drop, but their impact on the contractions of paretic tibialis anterior (TA) and medial gastrocnemius (MG) has remained inconclusive. This study thus investigated the effect of AFOs on these muscle contractions in stroke survivors. The contractions of paretic TA and MG muscles were assessed in twenty stroke patients and compared between walking with and without AFOs, using a novel wearable dynamic ultrasound imaging and sensing system. The study found an increase in TA muscle thickness throughout a gait cycle (p > 0.05) and a significant increase in TA muscle surface mechanomyography (sMMG) signals during the pre- and initial swing phases (p < 0.05) when using an AFO. MG muscle thickness generally decreased with the AFO (p > 0.05), aligning more closely with trends seen in healthy adults. The MG surface electromyography (sEMG) signal significantly decreased during the initial and mid-swing phases when wearing an AFO (p < 0.05). The TA-MG co-contraction index significantly decreased during initial and mid-swing phases with the AFO (p < 0.05). These results suggest that AFOs positively influenced the contraction patterns of paretic ankle muscles during walking in stroke patients, but further research is needed to understand their long-term effects.

Legal Protection for Fixed-Term Employment Contract Patterns based on Law No. 6 of 2023 on The Stipulation of Government Regulation in Lieu of Law No. 2 of 2022 on Job Creation

Legal Protection for Fixed-Term Employment Contract Patterns based on the Law of the Republic of Indonesia Number 6 of 2023 concerning the Stipulation of Government Regulation in Lieu of Law No. 2 of 2022 on Job Creation into Law is an interesting topic to study to provide the public with information regarding Fixed-Term Employment Contracts. This is because the sector of Fixed-Term Employment Contracts plays a very important role for workers in determining their welfare. The research method used is qualitative, with secondary legal sources utilizing normative and empirical legal research. The data obtained from the research show that both the government and society play a crucial role in shaping and supervising labor law policies. Legal protection for workers in Fixed-Term Employment Contracts must be fair and balanced between Fixed-Term and Permanent Employment Contract Workers. However, in the government's efforts to protect the workforce, there are still obstacles. It can be concluded that the regulation of Fixed-Term Employment Contracts in various laws and regulations reflects the government's ability to protect its people. These regulations must continuously be improved in accordance with the changing times, and oversight from the public is necessary as a control function to ensure that the latest regulations aim for the welfare of the people.

Neuromuscular fatigability is not affected by the contraction pattern of exercises with a similar mean torque.

Neuromuscular fatigability is task-dependent, but the influence of the contraction pattern on neuromuscular fatigability is largely unknown. Therefore, the present study aims to investigate if neuromuscular fatigability is affected by the contraction pattern of exhausting isometric exercises. Thirteen participants sustained a plantar flexors MVC for 1min (MVC1-MIN) before and after exhausting exercises designed to produce a similar mean torque (30% MVC), and following a 10-min rest period. Exercises consisted of intermittent (INT), continuous (CON) or variable (continuous contraction alternating between moderate and low intensity, VAR) contractions performed until task failure. The INT resulted in greater exercise duration and torque-time integral than CON and VAR. MVC similarly decreased after all exercises due to neural and muscular impairments. The torque loss during the MVC1-MIN increased after all exercises to a similar extent, mainly because of neural alterations. Contrary to MVC, the torque loss during the MVC1-MIN returned to baseline value after the recovery period. INT, CON and VAR exercises, performed with identical mean torque and until exhaustion, led to a similar neuromuscular fatigability. When the mean torque is matched among exercises, the contraction pattern does not influence the extent of neuromuscular fatigability, assessed through the maximal torque production and sustainability. The present findings are crucial to consider for the management of neuromuscular fatigability in physical conditioning in both athletes and patients.

Whole Gut Motility Patterns in Patients with Chronic Nausea and Vomiting.

Background/Objectives: Chronic nausea and vomiting (N/V) disorders are common in clinical practice. Our primary aim was to compare total and segmental gastrointestinal transit times as well as gastric contraction patterns in patients with chronic N/V syndrome to those of healthy volunteers (HVs). In the patient group, our secondary aim was to explore how symptoms and motility patterns were affected by a serotonin HT4 receptor agonist (Prucalopride). Methods: Patients with chronic N/V syndrome and HVs underwent baseline assessment of regional gastrointestinal (GI) motility/transit using the Motilis 3D-Transit system. Patients were then treated with Prucalopride 2 mg daily for 28 days, with the 3D-transit examination repeated within 10-20 days after treatment onset. Two self-administered questionnaires (the Gastrointestinal Symptom Rating Scale [GSRS] and Gastroparesis Cardinal Symptom Index [GCSI]) were used to assess patients' symptoms. Results: A total of 19 patients (13 F; median age 25 years (IQR 22-39) and 55 HVs (25 F; median age 28 (24-35) were included. At baseline, no differences in regional GI transit times were found between groups. However, patients had a significantly lower gastric contraction amplitude than HVs (9 mmHg (IQR 8-11) vs. 12 (10-15: p < 0.001). In response to Prucalopride treatment, gastric emptying time was reduced from a median of 3.1 h to 1.6 h (p < 0.005). Further, the GCSI was significantly reduced from GCSI 3.0 (IQR 2.3-3.7) at baseline to GCSI 1.9 (IQR 1.3-3.2) with Prucalopride. Conclusions: Patients with chronic N/V syndrome have significantly lower gastric contraction amplitude than HVs and may symptomatically benefit from prokinetics. They do not, however, have evidence of panenteric dysmotility.

Sex differences in deep brain shape and asymmetry persist across schizophrenia and healthy individuals: A meta-analysis from the ENIGMA-Schizophrenia Working Group.

Schizophrenia (SCZ) is characterized by a disconnect from reality that manifests as various clinical and cognitive symptoms, and persistent neurobiological abnormalities. Sex-related differences in clinical presentation imply separate brain substrates. The present study characterized deep brain morphology using shape features to understand the independent effects of diagnosis and sex on the brain, and to determine whether the neurobiology of schizophrenia varies as a function of sex. This study analyzed multi-site archival data from 1,871 male (M) and 955 female (F) participants with SCZ, and 2,158 male and 1,877 female healthy controls (CON) from twenty-three cross-sectional samples from the ENIGMA Schizophrenia Workgroup. Harmonized shape analysis protocols were applied to each site's data for seven deep brain regions obtained from T1-weighted structural MRI scans. Effect sizes were calculated for the following main contrasts: 1) Sex effects;2) Diagnosis-by-Sex interaction; 3) within sex tests of diagnosis; 4) within diagnosis tests of sex differences. Meta-regression models between brain structure and clinical variables were also computed separately in men and women with schizophrenia. Mass univariate meta-analyses revealed more concave-than-convex shape differences in all regions for women relative to men, across diagnostic groups ( d = -0.35 to 0.20, SE = 0.02 to 0.07); there were no significant diagnosis-by-sex interaction effects. Within men and women separately, we identified more-concave-than-convex shape differences for the hippocampus, amygdala, accumbens, and thalamus, with more-convex-than-concave differences in the putamen and pallidum in SCZ ( d = -0.30 to 0.30, SE = 0.03 to 0.10). Within CON and SZ separately, we found more-concave-than-convex shape differences in the thalamus, pallidum, putamen, and amygdala among females compared to males, with mixed findings in the hippocampus and caudate ( d = -0.30 to 0.20, SE = 0.03 to 0.09). Meta-regression models revealed similarly small, but significant relationships, with medication and positive symptoms in both SCZ-M and SCZ-F. Sex-specific variation is an overriding feature of deep brain shape regardless of disease status, underscoring persistent patterns of sex differences observed both within and across diagnostic categories, and highlighting the importance of including it as a critical variable in studies of neurobiology. Future work should continue to explore these dimensions independently to determine whether these patterns of brain morphology extend to other aspects of neurobiology in schizophrenia, potentially uncovering broader implications for diagnosis and treatment. Statistical analyses revealed significant main effects for diagnosis and sex in deep brain shape morphology. Among patients with schizophrenia, there was a pattern of thinning and surface contraction in the bilateral hippocampus, amygdala, accumbens, and thalamus, and a pattern of significant thickening and surface expansion in the bilateral putamen and pallidum compared to healthy control participants. Between males and females, there was a pattern of significant thinning and surface contraction in the bilateral thalamus, pallidum, putamen, and amygdala in females compared to males.There was no significant interaction between diagnosis and biological sex, suggesting that sex differences in deep brain shape and asymmetry among patients with schizophrenia reflect those observed in healthy individuals.Small but statistically significant relationships exist between brain structure and clinical correlates of schizophrenia were similar for both men and women with the disease, such that higher CPZ was associated with shape-derived thinning and surface contraction in the caudate, accumbens, hippocampus, amygdala, and thalamus, and elevated positive symptoms were associated with shape-derived thinning and surface contraction in the bilateral caudate, right hippocampus, and right amygdala.

Premature ventricular contraction patterns associated with nonsustained ventricular tachycardia

BackgroundOccurrence of nonsustained ventricular tachycardia (NSVT) is associated with negative outcomes. It is not clear whether specific electrocardiographic characteristics of premature ventricular contractions (PVCs) are associated with the occurrence of NSVT. The aim of this study was to identify electrocardiographic patterns associated with the presence of NSVT during 24-h electrocardiographic monitoring in patients with >10 PVCs per hour. MethodsThis was a retrospective, observational, cross-sectional study. We reviewed consecutive patients who received 24-h ECG monitoring performed at a single outpatient cardiology center. Patients who received 24-h electrocardiographic monitoring, with a PVC burden ≥10 PVCs/h were included. Occurrence of NSVT during 24-h electrocardiographic monitoring was the main outcome. ResultsA total of 343 patients were analyzed (mean [SD] age, 69.7 [12.5] years; 177 men [51.6 %]). NSVT occurred in 72 patients who were compared with 271 patients without NSVT. The novel term “premature beat ratio”, which aims to correlate the coupling interval and compensatory pause, was introduced; a value >0.5 was independently associated with NSVT according to the multivariate model (OR = 3.73, 95 % CI = 1.57–8.82; P = 0.002). PVC burden (OR = 1.09, 95 % CI = 1.02–1.17; P = 0.006), and triplets (OR = 18.19, 95 % CI = 7.32–45.18 P = 0.0) were also associated with NSVT in the multivariate model. ConclusionThese findings suggest that patients with a high PVC burden, triplets, and a premature beat ratio greater than 0.5 have an increased probability of presenting with NSVT and may benefit from more rigorous follow-up.

Novel image-analytic approach reveals new insights in fine-tuning of slime mould network adaptation.

This study introduces a novel methodology to explore the network dynamics of Physarum polycephalum, an organism celebrated for its remarkable adaptive capabilities. We used two innovative techniques to analyse its growth behaviour and network modifications under stress conditions, including starvation and differential epinephrine exposures. The first method provided a quantitative assessment of growth and exploration over time. The second method provided a detailed examination of vein diameter and contraction patterns, illuminating the physiological adjustments P. polycephalum undergoes in response to environmental challenges. By integrating these approaches, we were able to estimate the total network volume of the organism, with a focus on the normalized estimated volume, unveiling insightful aspects of its structural adaptations. While starvation reduced the volume, indicating a significant structural compromise, low and high epinephrine concentrations maintained a volume-to-area ratio comparable with the control. Determining the fractal dimension of the networks over time revealed a fine-tuning of the network complexity in response to environmental conditions, with significant reductions under stress indicating a constrained network adaptation strategy. These methods, novel in their application to P. polycephalum, provide a framework for future studies and a basis for exploring complex network behaviours with potential applications in bioengineering and adaptive network design.

Mapping uterine calcium dynamics during the ovulatory cycle in live mice.

Uterine contraction patterns vary during the ovulatory cycle and throughout pregnancy, but prior measurements have produced limited and conflicting information on these patterns. We combined a virally delivered genetically encoded calcium reporter (GCaMP8m) and ultra-widefield imaging in live nonpregnant mice to characterize uterine calcium dynamics at organ scale throughout the estrous cycle. Prior to ovulation (proestrus and estrus), uterine excitations primarily initiated in a region near the oviduct, but after ovulation (metestrus and diestrus), excitations initiated at loci homogeneously distributed throughout the organ. The frequency of excitation events was lowest in proestrus and estrus, higher in metestrus, and highest in diestrus. These results establish a platform for mapping uterine activity and demonstrate that an anatomically localized trigger for uterine excitations depends on the estrous cycle phase.

The Relationship Between Glabellar Contraction Patterns and Glabellar Muscle Anatomy: A Magnetic Resonance Imaging-based Study.

Glabellar contraction patterns were introduced to the scientific literature to help guide glabellar neuromodulator injection algorithms. However, the relationship between the underlying musculature and its influence on these glabellar contraction patterns is unclear. The aim of this study was to identify by magnetic resonance imaging (MRI) glabellar muscle parameters that display an influence on the distribution of individual glabellar contraction patterns. Thirty-four healthy young individuals of Caucasian Polish descent were investigated (17 females, 17 males) with a mean age of 23.6 years and a mean BMI of 22.8 kg/m2. MRI-based measurements of length, thickness, width, and surface area of procerus, corrugator supercilii, orbicularis oculi, and frontalis muscles were conducted. Unadjusted models revealed that there was no statistically significant difference between the 5 glabellar contraction types and the investigated muscle parameters, indicating that, independent of the skin rhytid pattern, the underlying musculature was not different between the investigated groups in this sample, with all P ≥ .102. Adjusted models revealed that sex was the most influential factor, with males generally displaying higher values for the investigated parameters than females. The results of this study reveal that, based on the MRI parameters investigated and the investigated cohort, there does not appear to be a strong relationship between glabellar contraction patterns and underlying glabella muscle anatomy. Utilizing glabellar contraction patterns to design neuromodulator treatment algorithms may be of variable clinical merit.

Adjuncts to annuloplasty in atrial functional mitral regurgitation.

Atrial fibrillation is the most common cardiac arrhythmia, leading to progressive dilation of cardiac chambers, abnormal contraction patterns of the atria and ventricles and, potentially, atrioventricular valvular insufficiency. Moreover, heart failure with preserved ejection fraction is often present and closely intertwined with disease initiation and progression. Surgical valve repair with a true-sized ring annuloplasty is a well-established treatment option in atrial functional mitral regurgitation. While early results are good, recent studies have brought the durability of this repair approach into question, highlighting the need for further refinement of the surgical strategy. In particular, repair strategies that simultaneously target the mitral valve as well as the left ventricle could provide improved repair durability.

Muscle thickness of lateral abdominal muscles in sitting and standing positions during abdominal drawing-in maneuver and abdominal bracing among healthy adults

Background: Spinal stabilization exercises, such as abdominal drawing maneuvers (ADIM) and abdominal bracing (AB), are crucial in alleviating low back pain, especially in functional positions such as sitting and standing. However, few studies have investigated the contraction patterns of the lateral abdominal muscles during ADIM and AB in these daily living positions (i.e., sitting and standing). Objective: The study aimed to investigate the thickness of transverse abdominis (TrA), internal abdominal oblique (IO), and external abdominal oblique (EO) during ADIM and AB between sitting and standing positions. Materials and methods: Twenty-four healthy adults (12 males, 12 females) without low back pain or other orthopedic conditions were assessed in sitting and standing positions while performing ADIM and AB. Real-time ultrasound imaging was used to measure the thickness of the TrA, IO, and EO during the ADIM and AB. Results: Muscle thickness of TrA and IO was significantly greater during ADIM when compared to AB (p&lt;0.05). TrA thickness during AB was significantly greater in sitting than standing (p&lt;0.05), but ADIM showed no difference in both positions. ADIM and AB can produce contraction of the lateral abdominal muscles (LAM) in both sitting and standing positions. Conclusion: ADIM and AB can produce contraction of the LAM in both sitting and standing positions. However, ADIM can activate TrA and IO muscles better than AB. Therefore, clinicians may initially consider using ADIM to teach individuals who need core stability exercises such as low back pain.