Body Size Research Articles

Return to sport activity following ultrasonographic diagnosis and conservative management of spontaneous injuries of the serratus cervicis ventralis and serratus thoracis ventralis muscles in 11 endurance horses.

To describe the clinical diagnosis, ultrasound findings, and outcome of 11 endurance horses with injuries to the serratus ventralis thoracis (SVT) or serratus ventralis cervicis (SVC) muscle. 11 endurance horses competing in medium- to high-level competitions and presenting with lameness caused by injuries to the SVT or SVC muscle, as confirmed by ultrasonography. Physical examinations revealed swelling caudal to the shoulder region associated with dorsocranial displacement of the scapula and edema of the ventral thorax for horses with SVT injuries. Swelling cranial to the scapula and edema of the pectoral area were identified among horses with injuries to the SVC. Dynamic examinations revealed moderate-to-severe reduction of the cranial phase of the stride at the walk; at the trot, a lameness score of 2 to 3/5 was assigned (modified American Association of Equine Practitioners Lameness Scale). Ultrasonography revealed moderate-to-severe increases in size of the muscle body, heterogeneous echogenicity, loss of the striated muscle pattern, and varying degrees of perimuscular edema. All horses were able to resume full training and competition in an average of 216 days (range, 74 to 362 days) and 148 days (range, 112 to 309 days) for injuries of the SVT and SVC, respectively. This case series is the first to describe the clinical and ultrasonographic features of spontaneous injuries to the SVT or SVC. Ultrasonography for diagnosis was simple and well tolerated by the horses.

Childhood-to-adulthood body size trajectory and cancer risk: a prospective cohort study

Abstract Background While excess weight in adulthood and childhood has been associated with increased cancer risk, the link between childhood-to-adulthood body size trajectories and cancer risk requires further investigation. Methods We used data from the UK Biobank, a prospective population-based cohort study. The main exposure was childhood-to-adulthood body size trajectory, constructed from self-reported body at age 10 (categories: thinner, average, and plumper than average) and measured body mass index (BMI) at recruitment (normal weight, overweight, and obese). Primary outcome was obesity-related cancer (13 different cancer types). Results During a median follow-up of 11.7 years, 21,289 participants developed obesity-related cancers. Having a larger body size at age 10 was strongly associated with being overweight or obese in adulthood. Compared to participants with average childhood to normal adulthood body size trajectory, all trajectories ending in overweight or obesity in adulthood were strongly associated with an increased risk of obesity-related cancers. The strength of the association was mostly determined by adulthood BMI, and similar patterns were observed for colorectal, endometrial, kidney, pancreatic and esophageal cancer. However, a larger body size in childhood was associated with a lower risk of postmenopausal breast cancer. Conclusions Although a larger body size in childhood predisposes to overweight and obesity in adulthood, it does not necessarily predispose to an increased obesity-related cancer risk if measures to maintain a healthy weight are taken in adulthood. Key messages • While larger body size in childhood predisposes individuals to overweight and obesity in adulthood, maintaining a healthy weight in adulthood may help mitigate the risk of obesity-related cancers. • Our findings highlight the importance of preventing and reducing overweight and obesity in adulthood for primary cancer prevention.

LCoRL regulates growth and metabolism.

Genome Wide Association Studies (GWAS) in humans and livestock have identified genes associated with metabolic traits. However, the causality of many of these genes on metabolic homeostasis is largely unclear due to lack of detailed functional analyses. Here we report Ligand Dependent Corepressor-Like (LCoRL) as a metabolic regulator for body weight and glucose homeostasis. Although GWAS data show that LCoRL is strongly associated with body size, glucose homeostasis, and other metabolic traits in humans and livestock, functional investigations had not been performed. We generated Lcorl knockout mice (Lcorl-/-) and characterized the metabolic traits. We found that Lcorl-/- pups are born smaller than the wildtype littermates (WT) before reaching normal weight by 7-9 weeks of age. While aging, Lcorl-/- mice remain lean compared to WT mice, which is associated with a decrease in daily food intake. Glucose tolerance and insulin sensitivity are improved in Lcorl-/- mice. Mechanistically, this stunted growth is linked to a reduction of circulating levels of insulin like growth factor-1. The expression of the genes downstream of growth hormone signaling and the genes involved in glucose and lipid metabolism are altered in the liver of Lcorl-/- mice. Furthermore, Lcorl-/- mice are protected against a high-fat diet (HFD) challenge and show reduced exercise capacity in an exercise stress test. Collectively, our results are congruent with many of the metabolic parameters linked to the Lcorl locus as reported in GWAS in humans and livestock.

Prediction of CRT response using a novel CRT responder score in an Asian patient population

Abstract Introduction Cardiac Resynchronization Therapy (CRT) guidelines, derived from trials among U.S. and European patients, assign weaker recommendations to those with midrange QRS duration (<150ms). Patient height and body size may modulate CRT efficacy. Moreover, these factors may affect CRT utilization and efficacy in Asia. Aim The purpose of this analysis was to determine the prediction scoring system model for CRT responders in a Japanese patient population. Methods We analyzed the database of the Multicenter Prospective Pilot Study to Test LV Intracardiac Conduction Time as a Predictor of CRT Response (BIO|SELECT) which was a single-arm study conducted at 28 hospitals in Japan. This study enrolled patients eligible for a de-novo CRT-defibrillator (CRT-D) based on current guideline indications, who had no recent or planned cardiac surgery and were planned to receive a Sentus ProMRI OTW quadripolar LV lead and a BIOTRONIK CRT-D with multipole pacing feature. Patients were followed for 7 months after implantation. Four accepted parameters to define CRT response [LVESV (cut-off -15%), LVEF (+5%), BNP (-25%), and NYHA class (one class improvement)] were combined into a composite benefit index (CBI) by forming the normalized sum, with CBI = 4.0 meaning response. The CBI was found to be more robust than the individual 4 parameters due to the reduced influence of noise and measurement errors in single parameters. Several factors were studied to create the scoring tool. The CRT responder score was the sum of these individual scores (range 0-100). To construct a predictive scoring system, logistic regression analysis was performed with a backward selection procedure. In addition, the Akaike information criterion (AIC) was applied to determine the best model among those tested. The score was then assigned employing the β coefficient of each variable divided by the reference value. The model's calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test. Results A total of 196 patients were enrolled in this study (mean age 69 years, mean LVEF 30%, left bundle-branch block [LBBB] 58%). The Ooccurrence of CRT response during the 7-month follow-up was 54%. Future CRT responders were significantly predicted by low age (< 70 years)(18 points), female (19 points), prior heart failure hospitalization (16 points), body mass index (<20) (17 points), QRS/height (<0.858)(30 points). This score predicted CRT response well (area under curve 0.72; 95% CI 0.643-0.798). When the cut-off of 63 points or more was applied the sensitivity was 0.56, the specificity was 0.72, and the negative predictive value was 0.58. Conclusions The CRT responder score is a novel approach for the prediction of CRT response, but should be validated and further improved to increase its predictive value. This approach highlights the role of preventing the development of severe heart failure and could help to identify individuals who might benefit from CRT.

Influence of peak exercise-induced blood pressure on basal to apical myocardial wall thickness in elite athletes: a sex-specific CMR study

Abstract Background Understanding the sex-specific physiological remodelling response of the myocardial walls to peak exercise-induced blood pressure (SBPpeak) is essential for distinguishing healthy adaptation from pathological remodelling in athletes. Purpose We investigated how SBPpeak relates to myocardial wall thickness measured using cardiac magnetic resonance imaging (CMR) in elite athletes. Methods Cross-sectional analysis of healthy elite athletes included in the ELITE study who underwent both cardiopulmonary exercise testing (CPET) and CMR. Imaging software’s built-in AI option determined average end-diastolic wall thicknesses of all sixteen AHA-defined segments on short-axis cine images with four-chamber long-axis reference. Our primary metrics of interest were Spearman's correlations between SBPpeak and left ventricular mass indexed to body surface area (LVM/BSA), as well as average wall thickness across the sixteen myocardial segments, stratified by sex and endurance/non-endurance sports status. Secondary analyses involved regression models to evaluate the influence of SBPpeak on myocardial wall thickness, adjusting for sex, body size, CPET variables and sport type. Results In 75 athletes (median age: 24; 71% female; 61% engaged in endurance sports), CPET and CMR were performed within a median interval of 5 months [interquartile range: 1-13 months]. SBPpeak was similar in female and male athletes (170 [160-180] vs. 174 [169-184] mmHg, p=0.121, respectively) and in endurance and non-endurance athletes (both 170 [160-180] mmHg, p=0.625). Female elite athletes showed weak to moderate positive correlations between SBPpeak and the majority of basal and mid-ventricular AHA segments (rho = 0.27 – 0.48, Figure). This was most pronounced in the mid-ventricular anterolateral segment (AHA06: rho = 0.48, p<0.001). LVM/BSA in females was positively correlated with SBPpeak (rho = 0.31, p=0.025). Male elite athletes demonstrated greater absolute wall thickness across all AHA segments compared to females, however, there was a moderate correlation with SBPpeak exclusive to the basal anterior segment (AHA01: rho = 0.48, p=0.028). Backward stepwise multivariate regression analyses (Table) revealed SBPpeak as an independent predictor of the thickness of all basal AHA segments except for the basal inferoseptal segment (AHA03), and the mid-anterior and anterolateral segments. Associationswere maintained after adjustment for maximum wattage, body surface area, and sex, with type of sports consistently excluded from the models. Conclusion In the extreme phenotypes of elite athletes, SBPpeak correlates especially with basal myocardial thickness, independent of sex, BSA and maximum work rate influences. We found stronger associations between SBPpeak and myocardial adaptation in female athletes. These findings suggest a paramount role of exercise-induced blood pressure on basal myocardial remodelling surpassing the effect of sports type.Figure:segmental polar plot (heat map)Table:GAM regression models

Relationship of body height to thoracic aortic length: implications for sex differences and normative values

Abstract Introduction The scaling of organ to body size is highly variable and can affect organ function in individuals of different sizes. Despite the relationship between aortic length and body size, to our knowledge, its scaling relationship has not been assessed. We assessed the allometric relationship between thoracic aortic length and body height and generated normative data for this important structural parameter. Methods Using a convolutional neural network (U-Net) we segmented the thoracic aorta among 49,282 UKBB participants who underwent magnetic resonance imaging. To define normal allometric relationships, we included a highly selected subgroup (n=3,856) without cardiovascular risk factors or prevalent cardiovascular disease. Allometric relations were estimated using sex-adjusted log-log models. Results The mean thoracic aorta centerline length was 31.68 (SD=2.50) cm. Males exhibited longer thoracic aortas than females (32.93 vs. 31.15 cm; P<0.0001). In log-log models, body height accounted for 13.4% of the population variability in thoracic aortic length (R2=0.134; P<0.0001). The allometric power relating thoracic aortic length to body height was highly sublinear (power point estimate=0.44; 95% CI:0.37, 0.50). Sex was a predictor of thoracic aortic length (β=0.02; 95%CI=0.014, 0.029; P<0.0001), indicating that for any given body height, females had slightly shorter thoracic aortas compared to males. Among males, the 5th, 25th, 50th, 75th and 95th percentiles of allometrically scaled aortic length were 2.69, 3.20, 3.36, 3.53, and 3.96, respectively. Among females, the corresponding percentiles were 2.69, 3.11, 3.29, 3.46, 4.01. Conclusions The thoracic aorta exhibits a highly sublinear length relationship with body height, suggesting that disproportionate length relationships at the extremes of body height may have an important impact on pulsatile hemodynamics. Females exhibit slightly shorter thoracic aortas than males even after accounting for body height in an allometric fashion.aorta length vs height

Cardiac magnetic resonance (CMR) height-based allometric scaling in Southeast Asians; implications in the diagnosis and prognosis of left ventricular hypertrophy (LVH): the REMODEL study

Abstract Background Left ventricular hypertrophy (LVH) is a strong predictor of adverse cardiovascular outcomes (1). Although normalizing LV mass (LVM) to height exponents has been shown to reduce variability from body size, specific recommendations for height exponents are lacking due to the scarcity of normal cohorts to define appropriate height exponents (2). Cardiac magnetic resonance (CMR) is increasingly used in assessing LVM, and the existing body of research is based primarily on the MESA cohort (3). While the MESA cohort is ethnically diverse, the intrinsic effects of ethnicity may not fully be discerned if certain ethnic groups are under-represented. Purpose We aimed to demonstrate the diagnostic and prognostic implications of establishing height exponents specific to sex in a Southeast Asian cohort. Methods Non-overweight/obese Southeast Asian healthy volunteers (n=416) were used to establish appropriate height exponents and normal reference ranges of LVM. The impact of these height exponents was examined in a separate cohort of Southeast Asians with hypertension (n=878). All individuals underwent standardized cardiovascular magnetic resonance imaging (CMR). Primary outcome was a composite of acute coronary syndrome, heart failure hospitalization, stroke, and cardiovascular mortality. Cox regression analysis of various LVH measures were adjusted for 24-hour systolic blood pressure, diabetes, and hyperlipidemia. Results The height exponents for healthy females and males were 1.57 and 2.33, respectively. In patients with hypertension, sex-specific height exponents significantly increased the detection of LVH compared with body surface area (BSA) indexing (47% [n=409/878] versus 27% [n= 236/878], p<0.001). Most individuals re-classified to LVH with sex-specific height exponents were overweight (33.1%, n=58/175) or obese (64.6%, n=113/175). There were 37 primary events over 60 [37-73] months of follow-up. Regardless of indexing method, LVH was independently associated with increased adverse events (sex-specific height exponent hazard ratio (HR): 2.8 [1.25-6.29], P=0.013). The prediction ability of LVH diagnosis by sex-specific height exponents was similar to BSA indexing (HR: 5.43 [2.49-11.8], P<0.001). Conclusions Reference ranges specific to the ethnicity, sex and imaging modality are necessary to establish appropriate height exponents. Although utilizing sex-specific height exponents to index LVM resulted in significantly more LVH reclassification when compared with BSA indexing, this did not translate to a notable improvement in event prediction. Further research into alternative methods of LVM indexing is warranted.Abstract SummaryPredictive Ability of LVH Measures

Prosthesis-patient mismatch is associated with long-term mortality following surgical aortic valve replacement

Abstract Background Prosthesis-patient mismatch (PPM) refers to a situation where the indexed effective orifice area (iEOA) of an implanted prosthetic valve is too small relative to the patient's body size, resulting in hemodynamic compromise. Studies examining the long-term consequences of PPM after surgical aortic valve replacement (SAVR) have yielded conflicting results. Purpose To evaluate the impact of PPM on long-term outcomes in patients undergoing primary isolated SAVR. Methods All patients who underwent isolated first-time SAVR from 1990-2014 were included in this observational, single-center study. PPM was defined as a predicted iEOA <0.85 cm2/m2 and severe PPM was defined as an iEOA <0.65 cm2/m2. Patient demographics, surgical details, and in-hospital outcomes were prospectively collected in our institutional database. Cases were linked to provincial administrative databases at an independent, non-profit research institute whose legal status allows it to collect and analyze health care and demographic data. The primary outcome of interest was all-cause mortality. Secondary outcomes were aortic valve reoperation (surgical or transcatheter) and post-operative hospitalization for heart failure. Multivariable Cox regression analysis identified risk factors for long-term mortality. Kaplan-Meier curves were generated for long-term survival and cumulative incidence functions for aortic valve reoperation and heart failure hospitalization. Results A total of 1,798 patients were included (no PPM: 770 [43%]; moderate PPM: 943 [52%]; and severe PPM: 85 [5%]). Mean age was 64±13 years, and 750 (42%) were female. 451 (25%) patients received a mechanical valve, and 1347 (75%) received a stented bioprosthetic valve. Concomitant aortic root enlargement was performed in 492 (27%) patients. At 20 years, survival was 47.8% (95% CI: 43.2%–52.2%) in the "no PPM group" compared with 29.5% (95% CI: 25.6%–33.5%) and 24.7% (95% CI: 12.7%–38.8%) in the moderate and severe PPM groups, respectively (p<0.001) (Figure 1). On multivariable analysis, iEOA was independently associated with long-term mortality (HR 0.95 per 0.10 increase in iEOA, 95% CI [0.91–0.98]; p=0.007). In a pre-specified subgroup analysis, iEOA was found to be associated with late mortality in patients younger than 65 years (p<0.001) but not in patients 65 years and older (p=0.23). Readmission for heart failure was more frequent among patients who had PPM than those who did not (Figure 2). There was no difference in aortic valve reintervention in patients with or without PPM (p=0.654). Conclusions Prosthesis-patient mismatch is common after SAVR and is associated with late mortality and hospitalization for heart failure. The deleterious impact of PPM on survival appears more pronounced in young patients. These findings may have important implications for the lifetime management of patients with aortic valve disease.Survival post SAVRHeart failure hospitalization post SAVR

Comparative population genomics analysis for chicken body sizes using genome-wide SNPs

Comparative population genomics analysis for chicken body sizes using genome-wide SNPs

Detection of biventricular volume increase in overweight and obese by using a novel index of the ideal human - a single center non-contrast-enhanced cardiac CT study

Abstract The bi-ventricular volume (BVV) can be measured from non-contrast-enhanced CT images in patients referred for coronary artery calcium (CAC) scoring. Such determined BVV has been found to correlate with left ventricular mass and to predict increased risk of all-cause and CV mortality in patients with type 2 diabetes mellitus. Currently, no data are available that quantifying the effect of body size on BVV using NCE-CT. We used a new indexing parameter that consisted of two parts: height and the difference between numerical values of height and body surface area (BSA). In the "ideal human", the difference is zero. Any deviation from this value determines the share of body mass regardless of height. Aim We hypothesize that a novel indexation way allows for better discrimination of the increased bi-ventricular volume in overweight and obese patients. Method We retrospectively analyzed the CT data from 2466 patients with CAC scoring over the last 15 years. Among them 1606 women and 860 men with an average age of 64 ± 11 years (range 21-93). The fatless bi-ventricular volume was measured manually using commercial software on a dedicated workstation (Vitrea2). Values of the raw (measured, ml) BVV and BVV normalized for height, BSA, and the novel parameter i.e. [h+ (h-BSA)], were compared in patients taking into account body mass index (BMI) categories of normal weight (25% of patients), overweight (40%) and obese (35%). Results Overall, the measured BVV [ml] was significantly greater in males (414±97) than in females (297±66) (p<0.001). BVV decreased non-linearly from before 40ties to mid-60ties, and then remained nearly stable. In normal-weight males, the measured BVV (370±80ml) was greater than in normal-weight females (279±61ml) (p<0.001). In overweight males, the BVV was 411±89ml; in overweight females, the BVV reached 290±59ml (p<0.001). These differences were non-significantly different from the sample of patients with normal BMI. In obese patients, mean values significantly differed between males and females (442±106 vs 321±71 ml, p<0.001). As the absolute value of the BVV should be interpreted in the context of body habitus, normalization for height, BSA, and the novel index were used. The results of these examinations are given in the figure. Conclusions Commonly used methods of indexing the volumetric parameters of the ventricles, as well as the novel indexing approach showed similar results in patients with normal body weight. The proposed indexation allowed for discriminating the increase in BVV that is easy to overlook in overweight. The use of body surface area for volumetric normalization is misleading as it provides similar values in normal, overweight, and obese patients, and should therefore be avoided. We should consider whether ventricular size standards based on a study population under 50 years of age create reliable conditions for detecting ventricular enlargement at an older age.

Echocardiographic insights redefining risk in pulmonary arterial hypertension: a focus on right atrial volume index for enhanced stratification

Abstract Introduction In Pulmonary arterial hypertension (PAH), the right atrium plays a critical role, and its size, determined by echocardiography, is crucial for risk stratification. Despite this, current guidelines still prioritize right atrial area (RAA) over the right atrial volume index (RAVI). This approach is contrary to the recommendations of international echocardiography societies since 2016, which advocate for the use of RAVI for a more accurate assessment. Purpose Identify the RAVI value corresponding to the RAA, in PAH risk stratification used in the 2022 ESC guidelines. Methods We conducted a retrospective analysis of all consecutive patients of a single-center, since 2002. Patient's echocardiograms were revised for simultaneous assessment of RAA and right atrial volume index (RAVI). Over an average follow-up of 6.7 years (SD 5.9), we recorded a cohort of 82 patients diagnosed with PAH. From this group, we excluded 27 patients with congenital etiologies, 14 due to the insufficient quality of echocardiographic data, and one patient identified as an extreme statistical outlier. A Pearson's correlation analysis was used to access the correlation between RAA and RAVI for PAH diagnosis. Results A total of 40 patients were included with a mean age at diagnosis of 48.85 years (SD 17.82), predominantly female (77.5 %). The most prevalent etiologies were idiopathic (32.5%) and connective tissue disease-associated PAH (27.5%). Clinical presentations included right heart failure signs in 30% of patients, rapid symptom progression in 12.5%, syncope history in 15% and 77.5% in WHO-FC III-IV. Average 6-MWD and NT-proBNP levels were 392,1 m (SD 120,2) and 1636,18 ng/L (SD 2576,14), respectively. Average hemodynamics parameters were right atrial pressure 7,39 mmHg (SD 4,940); cardiac index 2,28 L/min/m2 (SD 2,06); stroke volume index 3,38 mL/m2 (SD 3,92) and mixed venous oxygen saturation 65,68% (SD 10,86). Average echocardiographic parameters were RAA 20,14 cm2 (SD 4,80); TAPSE/sPAP 0,34 mm/mmHg (SD 0,18) and RAVI 37,78 mL/m2 (SD 13,67), with 10% of pericardial effusion. Statistical analysis revealed a strong and significant correlation between RAA and RAVI (r=0.82, 95% CI: 0.69-0.90, p<0.001). The derived linear relationship is expressed as "y=2.8*X -18". Therefore, an RAA value of 18 cm² translates to a RAVI of 32 mL/m², while an RAA of 26 cm² corresponds to a RAVI of 55 mL/m². Conclusion Our study supports a revision in HAP risk assessment guidelines, suggesting a shift to a more comprehensive approach using right atrial volume index (RAVI) measurements. We propose categorizing risk as low for RAVI < 32 mL/m², intermediate for RAVI between 32 and 55 mL/m², and high for RAVI > 55 mL/m². This recommendation aligns with the standards of international societies and is grounded in best clinical practices, considering that indexing measurements of the right atrium to body size potentially offers greater accuracy than absolute values.

Left atrial volume in obesity and hypertension: an innovative "ideal human" index allows for weighing their impact - a non-contrast cardiac CT study

Abstract Left atrial (LA) enlargement is a common and early feature of cardiac involvement in the natural history of obesity and arterial hypertension (AH). Mechanisms involved in this process are cumulative, and partly shared, thus separating and balancing their contributions is challenging. In a proportion of patients referred for coronary artery calcium (CAC) scoring, these clinical entities are present. The LA volume (LAV) is relatively easy to quantify from a CT scan. Measured LAV values can be misleading unless constitutional parameters (height (h) or body size area (BSA), are considered. We introduced a new indexing parameter, consisting of height and the difference between numerical values of height and BSA. In the "ideal human", the difference is zero. Any deviation from this value determines the share of body mass regardless of height. Aim We hypothesize that a novel indexation approach allows for earlier detection of the increased LAV in normotensive and AH patients considering the body mass index. Method We retrospectively analyzed CT data from 2535 patients, 1658 w (64±10 ys), and 876 m (aged 6±11ys), with CAC scoring over the last 15 years The LAV was determined by using commercially available software. The raw and indexed (for h, BSA, and the novel parameter [h+ (h-BSA)]) LAV volumes were compared in patients with normal BMI (<25kg/msg), overweight (25-29.9), and obesity (≥30) who with normal blood pressure or with AH. Results The LAV was larger in high BMI categories than in normal BMI. In non-AH subjects, the LAV increased from an average of 71 ml (normal) to 80 ml (overweight) and 90 ml (obese). In AH, the LAV increase showed a similar trend of averages (77, 88, 94 ml, F=2.59,p<0.01). Indexing LAVs were non-concordant, as shown in Figure. Thus, one can recognize that LAV normalization for the new index has brought the differences most evident and persuasive. In normal BMI, indexation ways did not significantly affect the LAV estimation. Whilst the body weight increased, no difference could be recognized for values indexing for BSA (red). The LAV indexation for height (blue) cannot help diagnose its increase in obesity. The distinguishing strength can be seen while using the [h-(h-BSA)] denominator (green). It indicates that in any scenario, body mass gain plays a greater role in the LAV increase than AH does. Conclusions Body mass is a more important factor that is associated with LAV than AH.. Common methods of LAV indexing, especially referred to as BSA, introduce errors leading to values mimicking normality in non-healthy people and should be forbidden. The proposed indexation way can help overcome the observed discrepancies and support early recognition of the consequences of obesity and hypertension.

Phylogenetic Insights Into Canidae Trait Variation Across Continents

ABSTRACTAimUnderstanding the spatial structuring of ecological communities involves considering the interplay between evolutionary history and environmental factors. This study investigates how the phylogenetic structure of Canidae influences the geographical distribution and trait patterns of lineages globally, and how these patterns relate to Bergmann's and Rapoport's rules.LocationAmericas, Africa, Eurasia.Time Period12 million years ago—present.Major Taxa StudiedCanidae.MethodsUsing distribution data and phylogenetic information for 37 Canidae species, we analysed key ecological, functional and evolutionary variables. We applied phylogenetic fuzzy‐weighting via principal coordinates of phylogenetic structure (PCPS) and variance partitioning analysis (VPA) to assess the contributions of phylogenetic structure and environmental factors to trait variation among species.ResultsOur results revealed distinct global patterns in body size, body weight, range size, habitat use and evolutionary distinctiveness among lineages. We also identified the shared contributions of phylogenetic structure and temperature to trait variation using variance partitioning analysis. The PCPS axes highlighted the influence of phylogenetic relationships on Canidae assemblages, particularly in South America.Main ConclusionsImportantly, the study challenges the applicability of Bergmann's and Rapoport's rules across continents. The unique diversification history of Canidae in South America and Africa and their diverse environmental conditions likely contribute to the observed trait patterns that make both continents so distinguished when compared to North America and Eurasia. Our findings underscore the need to incorporate phylogenetic information in models assessing trait variation across geographic scales for unbiased estimates.

Evaluation of the Growth Performance and Meat Quality of Different F1 Crosses of Tengchong Snow and Xichou Black Bone Chicken Breeds

Unlike other chicken breeds, Xichuan Black Bone (XBB) chickens are an established breed in China with excellent production performance and unique characteristics, including black meat, beaks, skin, bones, and legs, and they produce blue-shelled eggs. The Tengchong Snow (TS) chicken breed has relatively lower growth performance than commercial breeds but is considered one of the main genetic treasures of black meat in China. To improve the production and meat quality traits of the TS chickens by hybridization, the current study aimed to investigate the growth performance, carcass indices, meat quality physical properties, and muscle fiber traits of fiber traits of F1 crosses of TS with XBB chickens. Three groups of crossbreeding combinations were produced: (1) XT group (XBB × TS ), (2) TX group (TS × XBB ), and (3) TT group (TS × TS ), with the TT group used as a control. A total of 725 healthy chicks (XT group: 247, TX group: 180, TT group: 298) were reared up to 20 weeks of age to estimate the growth performance and associated meat parameters. The results showed that the XT and TX groups had higher body weight and body size compared with the TT group (p < 0.05). Similarly, breast width, breast length, width of body, and carcass weights were also greater (p < 0.05) in the XT and TX groups compared with the TT group. Meat physical properties, including color, water-holding capacity, and tenderness, were improved (p < 0.05) for the XT and TX group compared to the TT group. The XT group had the better color of the leg muscles with the unique orientation of muscle fibers. Based on the results, the XT group is more in line with the future breeding direction as they have greater body weight, larger size, and lower abdominal fat. This study is a baseline technical reference for the protection, evaluation, and utilization of germplasm resources of Tengchong Snow chicken for screening the best matching lines and combinations with local chickens.

The osteohistology of Orthosuchus stormbergi using synchrotron radiation microcomputed tomography.

Orthosuchus stormbergi was a small-bodied crocodyliform, representative of a diverse assemblage of Early Jurassic, early branching crocodylomorph taxa from the upper Elliot Formation of South Africa. The life history of these early branching taxa remains poorly understood, with only sparse investigations into their osteohistology, yet species like Orthosuchus have potential to inform about the macroevolution of growth strategies on the stem leading to crown crocodilians. In order to elucidate the growth patterns of Orthosuchus, we used propagation phase contrast X-ray synchrotron micro-computed tomography to virtually image the osteohistology of the postcrania of two specimens, including multiple elements from the type (SAM-PK-K409), and the femur of a referred specimen (BP/1/4242). In total, we scanned nine mid-diaphyseal sections of the humerus, radius, ulna, radiale, femur, tibia, fibula, and a rib. We then compared our results to osteohistological sections of crocodylomorph taxa from the published literature. Our results show that the most predominant bone tissue type in Orthosuchus is lamellar, with a few patches of woven and parallel-fibred bone. The type specimen contains four to five lines of arrested growth and the hindlimb elements present outer circumferential lamellae, whereas the referred specimen contains six to seven. Both specimens grew at similar rates, reaching adult skeletal body size at year four or five. The sectioned bones, most notably the radius and ulna, are comparatively thick walled and compact. Our virtual osteohistological sections are one of the first for an early branching crocodyliform, and the broad sample of skeletal elements makes Orthosuchus a key anchor point for understanding the plesiomorphic life history traits of the clade.

Predation on eggs and larvae of the Japanese brown frog Rana japonica Boulenger, 1879 by the invasive crayfish Procambarus clarkii (Girard, 1852) (Decapoda: Astacidea: Cambaridae) under laboratory conditions

Abstract We hypothesized that the North American invasive crayfish Procambarus clarkii (Girard, 1852) can negatively affect the populations of native frog species through predation. We conducted three laboratory experiments to examine whether P. clarkii can prey on eggs or larvae of the Japanese native frog Rana japonicaBoulenger, 1879: Experiment I crayfish + frog egg in an aquarium without a substrate or aquatic plants, Experiment II crayfish + frog larva in an aquarium without a substrate or aquatic plants, and Experiment III crayfish + frog larva in an aquarium with a substrate and aquatic plants as shelter for the larva. We used three experimental groups of crayfish individuals (small, intermediate, and large size), each of 10 individuals, and simultaneously placed one crayfish individual and one egg or frog larva in the same aquarium for 24 h and checked for predation by the crayfish. We found that 88.9% and 86.7% of eggs and larvae used in Experiments I and II were preyed upon, respectively. Predation rate of frog larvae was still high (77.8%) in Experiment III, suggesting that crayfish can potentially find and prey on frog larvae in nature. Predation on frog eggs or larvae was high regardless of the crayfish body size. Our results indicate that P. clarkii can potentially have a marked effect on the population of R. japonica by preying on eggs and larvae.

Among the world's smallest vertebrates: a new miniaturized flea-toad (Brachycephalidae) from the Atlantic rainforest.

The genus Brachycephalus includes miniaturized toadlets with two distinct morphotypes: brightly colored species with a bufoniform phenotype and smaller, cryptic species with a leptodactyliform phenotype. The diversity of leptodactyliform species is still underappreciated, and we generally lack fundamental information about their biology. Recent sampling efforts, including DNA analyses and recordings of advertisement calls, have improved our understanding of this group. In the present study, we describe a new species of Brachycephalus, one of the smallest vertebrates known. This new species is distinguished from its congeners by a combination of morphological, bioacoustic, and genetic data. Despite being among the smallest frogs globally (the second smallest amphibian species), it exhibits skeletal traits typical of larger frogs, such as the presence of cranial bones that are lost or fused in other miniature frogs, including other Brachycephalus. Our description underscores how new discoveries within the megadiverse fauna of the Atlantic Forest-a rich biodiversity hotspot-can provide insights into phenotypic variation, including vertebrate body size. By describing this new species, we also aim to revisit the hypothesis that the type series of B. hermogenesi includes two species, potentially including individuals of the species described here.

Body size and condition, not allochrony, affect temporal reproductive patterns in a prolonged breeding anuran

Body size and condition, not allochrony, affect temporal reproductive patterns in a prolonged breeding anuran

Cuticular hydrocarbons promote desiccation resistance by preventing transpiration in D. melanogaster.

Desiccation is a fundamental challenge confronted by all terrestrial organisms, particularly insects. With a relatively small body size and large surface-to-volume ratio insects are susceptible to rapid evaporative water loss and dehydration. To counter these physical constraints, insects have acquired specialized adaptations, including a hydrophobic cuticle that acts as a physical barrier to transpiration. We previously reported that genetic ablation of the oenocytes - specialized cells required to produce cuticular hydrocarbons (HCs) - significantly reduced survivorship under desiccative conditions in the fruit fly, Drosophila melanogaster. Although increased transpiration - resulting from the loss of the oenocytes and HCs - was hypothesized to be responsible for the decrease in desiccation survival, this possibility was not directly tested. Here we investigate the underlying physiological mechanisms contributing to the reduced survival of oenocyte-less (oe-) flies. Using flow-through respirometry we show that oe- flies, regardless of sex, exhibited an increased rate of transpiration relative to wild-type controls, and that coating oe- flies with fly-derived HC extract restored the rate to near wild-type levels. Importantly, total body water stores, including metabolic water reserves, as well as dehydration tolerance, measured as the percent of total body water lost at time of death, were largely unchanged in oe- flies. Together, our results directly demonstrate the critically important role played by the oenocytes and cuticular HCs to promote desiccation resistance.

Top-down racial biases in size perception: A registered replication and extension of

Biases in the perception and judgment of members of race-based and ethnicity-based minority groups are prevalent, often resulting in detrimental outcomes for these individuals. One such bias is a threat-related stereotype, associating specific race and ethnicity-based social groups with aggressiveness, violence, and criminality. In the US context, Black men are often victims of such bias. Recent evidence suggests that threat-related stereotypes are also linked to biased perceptions, such that perceivers overestimate the body size of Black relative to White men, even in the absence of perceptual differences between them. That is, mere top-down social category information was sufficient to induce perceptual biases in size perception related to threat (Wilson et al., 2017, Study 7). Considering the novelty of this finding and its theoretical importance, we suggested a registered replication of this finding to assess its robustness across laboratories, participants, and social groups. We conducted a direct replication (Study 1, N = 280) of the effect reported by Wilson and colleagues, followed by a conceptual replication (Study 2, N = 280) that tested the generalization of the original findings to another population (Israeli residents) and a different target social group (Muslim Israelis) frequently stereotyped as threatening in this population. Participants did not overestimate the body size of Black or Muslim Israeli targets, pointing to a failed replication of the original effect. These findings suggest that the effects of purely top-down social category information on threat-related perception and judgment are less robust than previously assumed.