Genotype correlates with clinical course and outcome of children with tight junction protein 2 (TJP2) deficiency-related cholestasis.

BACKGROUND AND AIMS: The study aimed to describe the clinical course and outcomes, and analyze the genotype-phenotype correlation in patients with tight junction protein 2 (TJP2) deficiency. APPROACH AND RESULTS: Data from all children with chronic cholestasis and either homozygous or compound heterozygous mutations in TJP2 were extracted and analyzed. The patients were categorized into 3 genotypes: TJP2-A (missense mutations on both alleles), TJP2-B (missense mutation on one allele and a predicted protein-truncating mutation [PPTM] on the other), and TJP2-C (PPTMs on both alleles). A total of 278 cases of genetic intrahepatic cholestasis were studied, with TJP2 deficiency accounting for 44 cases (15.8%). Of these, 29 were homozygous and 15 were compound heterozygous variants of TJP2 . TJP2-A genotype was identified in 21 (47.7%), TJP2-B in 7 cases (15.9%), and TJP2-C in 16 cases (36.4%), respectively. Patients with the TJP2-C genotype were more likely to experience early infantile cholestasis (87.5% vs. 53.5%, p =0.033), less likely to clear jaundice (12.5% vs. 52.2%, p =0.037), more likely to develop ascites, and had higher serum bile acids. Patients with the TJP2-C genotype were more likely to die or require liver transplantation (native liver survival: 12.5% vs. 78.6%, p <0.001), with a median age at death/liver transplantation of 2.5 years. Cox regression analysis revealed that TJP2-C mutations ( p =0.003) and failure to resolve jaundice ( p =0.049) were independent predictors of poor outcomes. CONCLUSIONS: Patients with the TJP2-C genotype carrying PPTMs in both alleles had a rapidly progressive course, leading to early decompensation and death if they did not receive timely liver transplantation.

Data-driven discovery of stochastic dynamical equations of collective motion.

Coarse-grained descriptions of collective motion of flocking systems are often derived for the macroscopic or the thermodynamic limit. However, the size of many real flocks falls within 'mesoscopic' scales (10 to 100 individuals), where stochasticity arising from the finite flock sizes is important. Previous studies on mesoscopic models have typically focused on non-spatial models. Developing mesoscopic scale equations, typically in the form of stochastic differential equations, can be challenging even for the simplest of the collective motion models that explicitly account for space. To address this gap, here, we take a novel data-driven equation learning approach to construct the stochastic mesoscopic descriptions of a simple, spatial, self-propelled particle (SPP) model of collective motion. In the spatial model, a focal individual can interact withkrandomly chosen neighbours within an interaction radius. We considerk = 1 (called stochastic pairwise interactions),k = 2 (stochastic ternary interactions), andkequalling all available neighbours within the interaction radius (equivalent to Vicsek-like local averaging). For the stochastic pairwise interaction model, the data-driven mesoscopic equations reveal that the collective order is driven by a multiplicative noise term (hence termed, noise-induced flocking). In contrast, for higher order interactions (k > 1), including Vicsek-like averaging interactions, models yield collective order driven by a combination of deterministic and stochastic forces. We find that the relation between the parameters of the mesoscopic equations describing the dynamics and the population size are sensitive to the density and to the interaction radius, exhibiting deviations from mean-field theoretical expectations. We provide semi-analytic arguments potentially explaining these observed deviations. In summary, our study emphasises the importance of mesoscopic descriptions of flocking systems and demonstrates the potential of the data-driven equation discovery methods for complex systems studies.

Fabrication of CuNPs Using Schiff Base Ligand and Their Catalytic Reduction of Pharmaceutical Drugs, Fluorescence Selective Detection of Cd2+, Antimicrobial, and Antioxidant Activities.

Here, we have approached the synthesis of copper nanoparticles (CuNPs) Schiff base (5-trifluoromethoxy-2-(((2chloro-5-(methyl)phenyl)imino)methyl)phenol)). The synthesized CuNPs were characterized by UV-vis spectroscopy, PL, FTIR, powder XRD, and TEM analysis. From the UV-vis absorption spectroscopy, an absorption peak was observed at 585 nm. As a result of the powder XRD and TEM studies, spherical particle sizes ranged between 4 and 10 nm. FT-IR analysis confirmed the presence of functional groups ‒OH, C=C, -C=N-, and C‒H triggers the synthesis of CuNPs. Further, the catalytic property of the CuNPs were revealed by the degradation of pharmaceutical drugs such as Capecitabine (CAP) and Ciprofloxacin (CIP) in 90 min of reaction time in the presence of NaBH4. The reaction kinetics followed pseudo-first-order with k-values (rate constant) 0.248 min-1 and 0.307 min-1. In addition, the synthesized CuNPs have exhibited selective sensing detection of Cd2+ metal ions in different range of concentration (10-100 µM) by spectrofluorometrically with the limit of detection (LOD) is 0.0284 nM and limit of quantification (LOQ) is 0.0586 nM. The CuNPs revealed significant antioxidant activities against DPPH as a common free radical at 50 µg/mL with 71.24% of scavenging activity. The maximum antimicrobial potential and zone of inhibition of P. Aeruginosa is 17.25±0.8 mm and A. niger is 12.1 mm by using CuNPs.

Influence of convective hot air drying on physico-functional, thermo-pasting and antioxidant properties of elephant foot yam powder (Amorphophallus paeoniifolius).

The present study focused on the effect of different drying temperatures (40, 50, 60 and 70 °C) and combination of pre-treatments: potassium metabisulphite (KMS), potassium metabisulphite + Citric acid + blanching (KCB)] on functional, thermo-pasting and antioxidant properties of elephant foot yam (EFY) powder. Drying temperature and pretreatment reduces the water and oil absorption capacity, and the highest values were 2.34 g/g and 1.19 g/g for drying at 40 °C for the untreated sample, respectively. KMS pretreatment enhanced the bulk density, foaming capacity, emulsion capacity, and emulsion stability with an increase in drying temperature. Pasting temperature and viscosity decreased with an increase in drying temperature, and the maximum was observed at 40 °C for KMS pretreatment. Blanching increases the gelatinization temperature resulting in higher mid-and end-temperatures for KCB pretreatment. The antioxidant properties decreased with an increase in the drying temperature and were found to be minimal in the case of KCB treated samples.

Manual small incision cataract surgery: a viable option for cataract with pseudoexfoliation.

PURPOSE: The aim of the study was to assess the spectrum of clinical presentation, intraoperative challenges and immediate surgical outcome of cataract patients with pseudoexfoliation syndrome (PXF) following manual small incision cataract surgery (MSICS). METHODS: This prospective observational study which was conducted in a rural tertiary care hospital included adult patients with cataract and associated PXF. MSICS was performed for all after a complete ophthalmic and systemic examination. Clinical profile, intraoperative and post-operative complications were noted. Uncorrected visual acuity on first day post-surgery was used to assess the surgical outcome following MSICS. RESULTS: MSICS was performed in 80 eyes with varying grades of cataract and PXF. The mean age of the patients was 62.5 ± 8.9 years. PXF material on pupillary margin in 77(96%) patients was the most common finding noted. Majority of the patients had advanced cataract (72, 90%) and inadequate mydriasis (62, 77.5%). Posterior capsular rent (8, 10%) and zonular dehiscence (8, 10%) were the intraoperative difficulties faced. Uncorrected visual outcome on first post-operative day was moderate to good in 71 (88.8%) patients, limited by post-operative corneal oedema (21, 26.3%), iritis (31, 38.8%) and aphakia (9, 11.3%). CONCLUSION: Patients with pseudoexfoliation had poor pupillary dilatation, advanced cataracts and higher rate of posterior capsular rent. Our study showed good outcome of MSICS in PXF patients, even with advanced cataract suggesting that MSICS is a safe, effective and viable option for patients with PXF and cataract.

Comparative transcriptome analysis of Ethiopian indigenous chickens from low and high altitudes under heat stress condition reveals differential immune response.

Ethiopia is an ecologically diverse country; the low altitude regions are hot and humid whereas the high altitude regions are cooler. In this study we analyzed the transcriptome response of high altitude (Addis Ababa) and low altitude (Awash) chickens to heat stress conditions that are prevalent in the low altitude regions. The chickens were free ranged for 20 h in an enclosure in Awash, and then the heart, breast muscle and spleen tissues were collected at 6:00 am, 12:00 noon and 6:00 pm to follow a daily circadian cycle. Through RNA-sequencing analysis, we identified differentially expressed genes (DEGs) that were significant (q < 0.05). These DEGs were subjected to protein-protein interaction (PPI) network and gene co-expression network (GCN) analyses to understand their role. KEGG pathway analysis and Gene Ontology analysis of all the identified DEGs and the genes identified from the PPI network and GCN analyses revealed that several immune-related pathways, such as proteasome, focal adhesion, influenza A, the ErbB signaling pathway and glycerophospholipid metabolism, were enriched in response to heat stress. These results suggest that the high altitude chickens were under heat stress and might be immunologically susceptible. Our findings will help in developing a genetic approach to mitigate production loss due to heat stress.

Evaluation of Circulating Plasma VEGF-A, ET-1 and Magnesium Levels as the Predictive Markers for Proliferative Diabetic Retinopathy.

Diabetic retinopathy (DR) is the most common cause for preventable blindness in India. The onset of micro and macrovascular complications in T2DM is multifactorial and difficult to predict. The status of micronutrients, several inflammatory cytokines, elevated triacylglycerols, oxidative stress etc., are being studied extensively. Hypomagnesemia plays a pivotal role in worsening of insulin resistance. Although, Vascular Endothelial Growth Factor-A (VEGF-A) and Endothelin-1 (ET-1) are known to be elevated in DR, yet few reports cite their role, especially in Indian population. In this study, we included thirty subjects with T2DM in each of the three groups namely, T2DM cases without retinopathy, Non Proliferative DR (NPDR) and Proliferative DR (PDR) retinopathy. The glycemic status, circulating plasma VEGF-A, ET-1 levels, serum magnesium and lipids were estimated and compared among the groups. An ROC was drawn to evaluate VEGF-A, ET-1 and serum magnesium levels as the predictive markers for PDR. On comparison VEGF-A, ET-1 and serum magnesium levels showed a significant difference among the three groups. PDR cases had higher circulating levels of VEGF-A, ET-1 and low serum magnesium levels when compared to others. ROC for VEGF-A and ET-1 showed an optimum cut-off of 1521 ng/ml (AUC 0.975) and 16 pg/ml (AUC 0.96) respectively. A negative ROC was drawn to check the lower cut-off limit for serum magnesium; we documented an optimum cut off of 1.7 mg/dl (AUC 0.837). ET-1, VEGF-A and serum Magnesium levels are significantly altered in PDR and can be used as the predictive markers of PDR.

The financial sustainability of the World Health Organization and the political economy of global health governance: a review of funding proposals.

The World Health Organization (WHO) continues to experience immense financial stress. The precarious financial situation of the WHO has given rise to extensive dialogue and debate. This dialogue has generated diverse technical proposals to remedy the financial woes of the WHO and is intimately tied to existential questions about the future of the WHO in global health governance. In this paper, we review, categorize, and synthesize the proposals for financial reform of the WHO. It appears that less contentious issues, such as convening financing dialogue and establishing a health emergency programme, received consensus from member states. However, member states are reluctant to increase the assessed annual contributions to the WHO, which weakens the prospect for greater autonomy for the organisation. The WHO remains largely supported by earmarked voluntary contributions from states and non-state actors. We argue that while financial reform requires institutional changes to enhance transparency, accountability and efficiency, it is also deeply tied to the political economy of state sovereignty and ideas about the leadership role of the WHO in a crowded global health governance context.

A comparative proteomic analysis of blood serum for developmental stages in pigs.

This study aimed to differentiate genes at developmental stages of pigs from 0 to 150 days of age, to build up a protein database and to find candidate genetic markers for growth traits. The analysis of two-dimensional electrophoresis and matrix-assisted laser-desorption/ionization mass spectrometry separated 252 protein segments. After successfully blasting the peptide sequences, the analysis confirmed 37 differentially expressed proteins that increased from birth to 150 days of age (type A), whereas the type B proteins presented the inverse pattern. The type C proteins included proteins that were expressed continuously throughout the developmental periods. A total of 319 primer sets for 33 genes were designed to find genetic variants using pooled DNA samples of Yorkshire pigs. Amplification products for all primer sets produced approximately 20 000 clones that were sequenced, and 48 candidate SNP sites were finalized for genotyping. A total of 475 animals were used for high throughput genotyping analysis. Among these, phenotype data of all 475 animals were collected for average daily gain, backfat thickness and days to 90 kg, whereas feed conversion data were collected for 300 animals and body measurement traits (starting weight, ending weight, body length, wither height and chest depth) were collected for 209 animals. Association analysis found significant statistical differences between the animals having genotypes of 13 SNPs (g.78935883C>T, g.147629986C>T, g.98266037T>C, g.214707340G>A, g.88350299C>T, g.17180956C>T, g.17181024C>T, g.2350283A>G, g.138361311C>T, g.44996379C>T, g.44996247A>C, g.107715245C>T, g.4149631C>T) for the various measured traits. The identified genetic polymorphisms, of which one was novel (g.214707340G>A), may serve as candidate molecular markers to change population means for the targeted growth traits.

The virulence polysaccharide Vi released by Salmonella Typhi targets membrane prohibitin to inhibit T-cell activation.

T cells are critical to immunity against pathogenic Salmonella including Salmonella Typhi which causes systemic infection, typhoid, in humans. The strategies that this pathogen employs to keep T-cell mediated immune responses in check during establishment of systemic infection are not completely understood. Here, we show that the virulence polysaccharide Vi, which distinguishes S. Typhi from localized gastroenteritis-producing nontyphoidal Salmonella serovars, is a potent inhibitor of T-cell activation. Vi released by S. Typhi interacts with the membrane prohibitin complex and inhibits IL-2 secretion from T cells stimulated through the T-cell receptor (TCR) but does not affect PMA-activated interleukin 2 (IL-2) secretion. Treatment with Vi suppresses early activation events including TCR down-regulation, actin polymerization, and phosphorylation of ERK. Coadministration of Vi with anti-CD3 Ab reduces secretion of IL-2 and interferon γ in mice. Our findings reveal a mechanism by which S. Typhi may target T-cell immunity during establishment of typhoid.

In situ production of low-modulus Ti-Nb alloys by selective laser melting and their functional assessment toward orthopedic applications.

This work aimed to manufacture Ti-28.5Nb and Ti-40.0Nb (wt%) alloys in situ via selective laser melting (SLM) from Ti and Nb elemental powders. X-ray diffraction analysis revealed complete ß-phase (cubic) in Ti-40.0Nb and a mixture of (α'' orthorhombic + ß cubic) phases in Ti-28.5Nb were formed, whereas few of the Nb particles remained only partially fused during manufacturing. The fraction of partially melted Nb particles was determined as ∼2 and ∼18% in Ti-28.5Nb and Ti-40Nb, respectively. Mechanical characterization revealed higher hardness and more strength in Ti-28.5Nb than in Ti-40.0Nb due to the presence of the α'' phase in the former. Tribocorrosion tests reveal a significantly better wear-corrosion resistance for Ti-40.0Nb, as determined from a lower total volume loss in Ti-40.0Nb (∼2 × 10-4 mm-3) than in Ti-28.5Nb (∼13 × 10-2 mm-3). The lower volume loss and better corrosion resistance behavior are attributed to the ß phase, which was dominant in Ti-40.0Nb. Cell studies reveal no toxicity for up to 7 days. Both the alloys were better at supporting cell proliferation than wrought Ti6Al4V. This study presents a route to preparing Ti-Nb alloys in situ by SLM that are promising candidates for biomedical applications.

Neglected patellar tendon ruptures: a simple modified reconstruction using hamstrings tendon graft.

PURPOSE: We hereby describe a cost effective and simple anatomical reconstruction without requirement for allograft or implants for neglected chronic patellar tendon injuries. This has been validated in seven patients with an average follow up of greater than three years resulting in good outcome. METHODS: Seven patients (six males, one female) of mean age 41.8 years (range up to 57 years) presented with neglected patellar tendon injury. The time since injury ranged between three months and three years (average nine months). Active extension was not possible in three patients, and four patients had an extensor lag between 40° and 80° (average 62.5°). Four patients had quadriceps strength of grade 2/5 and three patients had grade 3/5. All patients had severe functional limitation with an average IKDC score of 46.8 (range 39-57). They all underwent patellar tendon reconstruction using hamstrings tendon autograft. RESULTS: Postoperatively with a mean follow up of 40.7 months (range 31-52 months), all patients had a stable knee with mean flexion of 125° (range 120°-130°) and without any extension lag. Quadriceps power was regained in five cases to 5/5 and in two cases to 4/5. With an improvement in the IKDC score to 86.8 (range 80-92), excellent outcome was noted in five patients and good outcome in two patients. The average postoperative Lysholm score was 92.4 (range 89-95) and the average Kujala score was 94.5 (range 92-97). CONCLUSION: Patellar tendon reconstruction using hamstrings autograft for neglected patellar tendon injuries provides good stability and excellent outcome. Compared to previous techniques described, our technique is unique in being cost effective and a simple anatomical reconstruction without the requirement for allograft or implants.

An in vitro evaluation of diametral tensile strength and flexural strength of nanocomposite vs hybrid and minifill composites cured with different light sources (QTH vs LED).

BACKGROUND: Composites always remained the target of discussion due to lot of controversies around it. Mechanical properties are one of them. With the introduction of new technology and emergence of various composites which combine superior strength and polish retention, nanocomposites have led to a new spark in the dentistry. A recent curing unit LED with various curing modes claims to produce higher degree of conversion. The aim of this study was to evaluate the diametral tensile strength and flexural strength of nanocomposite, hybrid and minifill composites cured with different light sources (QTH vs LED). MATERIALS AND METHODS: Seventy-two samples were prepared using different specially fabricated teflon molds, 24 samples of each composite were prepared for the diametral tensile strength (ADA specification no. 27) and the flexural strength (ISO 4049) of the 12 samples, six were cured with LED (Soft Start curing profile) and other six with QTH curing light and tested on a universal testing machine. RESULTS: The nanocomposite had highest diametral tensile strength and flexural strength which were equivalent to the hybrid composite and superior than the minifill composite. CONCLUSION: With the combination of superior esthetics and other optimized physical properties, this novel nanocomposite system would be useful for all posterior and anterior applications.

Intraocular Pressure Changes Following Three "Head below the Heart" Postures in Yoga Practitioners - A Prospective Observational Study.

Context: Intraocular pressure (IOP) increases during "sirasasana" and may be a risk factor for the progression of glaucoma. Other "head below heart" asanas may also cause increase in IOP. Aims: To determine the change in IOP following three "head below the heart" postures-"meruasana", "viparithakarni," and "sarvangasana". Settings and Design: Prospective observational study conducted in a tertiary care hospital over 3 weeks. Materials and Methods: Willing, regular yoga practitioners recruited by purposive sampling performed "meruasana", "viparithakarni," and "sarvangasana" in random order according to a 3 × 3 periods cross over study design after baseline measurement of IOP, blood pressure (BP), and pulse rate. Each asana was held for 30 s. Within 15-30 s of completion of asana, IOP, BP, and pulse rate were recorded. There was an interval of 30 min between the asanas. Statistical Analysis Used: Normality of data was tested using the Kolmogorov-Smirnov test. Repeated measures of ANOVA with Tukey-Kramer multiple comparisons was used to compare changes in IOP, BP, pulse rate following asana. P ≤ 0.05 was accepted as statistically significant. Results: There were 33 participants with a mean age of 29.6 ± 10.5 years (95% confidence interval [CI]: 26.02, 33.18). The mean baseline IOP was 15.5 ± 3.4 mm Hg (95% CI: 14.34, 16.66) in the right eye and 16.7 ± 3.4 mm Hg (95% CI: 15.54, 17.86) in the left eye. IOP showed a significant reduction following each of the three asanas (P < 0.0001). However, neither pulse rate (P = 0.53) nor BP (P = 0.27) showed any change following the asanas. Conclusions: "Meruasana," "viparithakarni," and "sarvangasana" when held for 30 s by healthy yoga practitioners resulted in post-asana drop in IOP with no significant change in pulse rate or BP.

Condylar hyperplasia.

Condylar hyperplasia (CH), as the name suggests, affects mandibular condyle producing overgrowth of condyle, which is characterized by a slowly progressive, usually unilateral enlargement of the mandible, facial asymmetry and deviation of chin to the unaffected side. The condition is known to be self-limiting, usually begins around puberty, but may not be recognized until later in life. This paper reports a case of severe facial asymmetry secondary to CH, which was successfully treated by high condylectomy only.

Membrane prohibitin forms a dynamic complex with p56lck to regulate T cell receptor signaling.

Prohibitin is a highly conserved ubiquitously expressed protein involved in several key cellular functions. Targeting of this protein in the membrane by the virulence polysaccharide, Vi, of human typhoid-causing pathogen, Salmonella enterica serovar Typhi (S. Typhi), results in suppression of IL-2 secretion from T cells activated through the T-cell receptor (TCR). However, the mechanism of this suppression remains unclear. Here, using Vi as a probe, we show that membrane prohibitin associates with the src-tyrosine kinase, p56lck (Lck), and actin in human model T cell line, Jurkat. Activation with anti-CD3 antibody brings about dissociation of this complex, which coincides with downstream ERK activation. The trimolecular complex reappears towards culmination of proximal TCR signaling. Engagement of cells with Vi prevents TCR-triggered activation of Lck and ERK by inhibiting dissociation of the former from prohibitin. These findings suggest a regulatory role for membrane prohibitin in Lck activation and TCR signaling.

Therapeutic Enteral Formulas in Children.

PURPOSE: A variety of enteral formulas for various diseases have become available in India in the last few years. Awareness among pediatricians about the availability and indications for these therapeutic formulas is low. METHODS: A literature search was conducted in PUBMED and relevant data collected from all English language publications available. Data on the commercial preparations was sourced from the individual companies, the Diet 4 life initiative as well as FSSAI (Food safety and standards authority of India). CONCLUSIONS: Therapeutic enteral formulas, which are indicated in various disease states belong to four categories - lactose modified, hydrolyzed, MCT based and metabolic disease specific formulas. Lactose modified formulas which are used in temporary or permanent lactose intolerance and Galactosemia are either casein or soy protein based. Hydrolyzed formulas could be partially hydrolyzed, extensively hydrolyzed or amino acid based. Only extensively hydrolyzed formula should be recommended in milk protein allergy. Amino acid (elemental) formulas are mainly indicated in patients with diffuse intestinal mucosal disease. MCT formulas are used in chronic liver disease with cholestasis, and have 30 to 80% MCT. Formulas for inborn errors of metabolism are free of specific carbohydrate, amino acid or fatty acid. Proprietary formulas presently available in India with their specifications have been listed.

The use of marine sponge, Haliclona tenuiramosa as bioindicator to monitor heavy metal pollution in the coasts of Gulf of Mannar, India.

The results of the present research study indicate that the heavy metal accumulation in the marine sponges provide evidence as an excellent bioindicators for monitoring heavy metal pollution between near and offshore environments of Mandapam coast of "Gulf of Mannar (GoM), India". The heavy metal concentrations in sea water and accumulation in the tissues of Haliclona tenuiramosa were analyzed by ICP-MS (inductively coupled plasma-mass spectrometry). The concentrations of metals in the coastal waters of nearshore (< 0.5 km from shore) were always higher than those in the offshore waters (2-5 km away from shore). Likewise, sponges living in the nearshore accumulated greater concentrations of heavy metals (As, Cd, Co, Cu, Fe, Mn and Ni) ranging from 2 to 17 times higher concentration than the sponges located away from the shore. A positive correlation between concentration levels in water and bioaccumulation in tissues was observed. The bioaccumulation of heavy metals in sponge tissue were in order of Fe > Mn > Ni > Cu > As > Co > Cd in both the near and offshore stations. The present results justified that a more comprehensive monitoring of presence of heavy metals in H. tenuiramosa of surrounding GoM, is necessary to help a better mitigation of the problem.

Fission-fusion dynamics and group-size-dependent composition in heterogeneous populations.

Many animal groups are heterogeneous and may even consist of individuals of different species, called mixed-species flocks. Mathematical and computational models of collective animal movement behavior, however, typically assume that groups and populations consist of identical individuals. In this paper, using the mathematical framework of the coagulation-fragmentation process, we develop and analyze a model of merge and split group dynamics, also called fission-fusion dynamics, for heterogeneous populations that contain two types (or species) of individuals. We assume that more heterogeneous groups experience higher split rates than homogeneous groups, forming two daughter groups whose compositions are drawn uniformly from all possible partitions. We analytically derive a master equation for group size and compositions and find mean-field steady-state solutions. We predict that there is a critical group size below which groups are more likely to be homogeneous and contain the abundant type or species. Despite the propensity of heterogeneous groups to split at higher rates, we find that groups are more likely to be heterogeneous but only above the critical group size. Monte Carlo simulation of the model show excellent agreement with these analytical model results. Thus, our model makes a testable prediction that composition of flocks are group-size-dependent and do not merely reflect the population level heterogeneity. We discuss the implications of our results to empirical studies on flocking systems.