Group Size Research Articles

Bat Hibernation: In Groups or Individually?

This study focuses on the hibernation behavior of the western barbastelle bat (Barbastella barbastellus) in underground systems in Poland from 2006 to 2011, specifically during the peak hibernation months of December to February. The impact of climate parameters, namely temperature (T), humidity (Rh), and air flow velocity (v), on the clustering behavior of bats during hibernation was investigated. The climate parameters varied within specific ranges: T fluctuated between 6.0 and 12.4 °C, Rh ranged from 56.4 to 91.8%, and v varied from 0.01 to 1.17 m/s. The quantile linear regression method for statistical analysis of the results was employed. This study found that certain combinations of climate parameters influenced the grouping behavior of bats during hibernation. The model structural parameters revealed the following relationships: 1. An increase in the product of T and v led to an increase in the bats’ group size. 2. For pairs of variables such as T and Rh, and Rh and v, an increase in their product resulted in a decrease in the bats’ group size. 3. When considering the product of T, Rh, and v, a decrease in the bats’ group size was also observed.

(079) Perception of Signals of Sexual Interest in Patients with Schizophrenia

Abstract Introduction Patients with schizophrenia (SCH) face many difficulties in forming and maintaining sexual relationships and often have unmet needs around intimacy. Low satisfaction with sexual relationships has been linked to a decrease in overall quality of life. Single relationship status also correlates with a poorer prognosis. However, the exploration of sources of sexual and relationship deficits in patients is an area that is habitually neglected, and there is little research addressing this phenomenon. Objective Our study aims to identify whether difficulties in forming sexual relationships reported by patients with SCH could be connected to: a) a compromised ability to interpret, recognize and respond to signals of sexual interest b) decreased salience of sexual intimacy. Methods Sample: Twenty male and female patients with schizophrenia and a control group of the same size, matched for demographic parameters, will be recruited from the Study of first episodes of schizophrenia (ESO). ESO is a large prospective database dedicated to the longitudinal follow-up of first-episode patients with SCH which contains a wealth of information on bio-psycho-social markers. Procedure: The variables of interest will be tested by two experiments developed in our laboratory. The first experiment depicts male and female actors showing behavioral displays conveying signals of a) sexual interest, b) neutral but friendly attitude and c) rejection, towards the observer. The second experiment is a simple viewing task designed to assess the salience of erotic stimuli compared to neutral ones. In addition, eye movements and pupil dilation will be measured using the eye-tracking device Eyelink 1000plus. Statistical analysis: A repeated-measures t-test will be used to assess the change in a continuous outcome. Results Preliminary results show that the patients (N=10) spent more time on erotic images (mean time= 884.69 ms) than the control group (N=9) (mean time= 772.14 ms). This difference is not statistically significant (p = 0.21). Currently, more data are being collected. Conclusions The preliminary results demonstrate that there is no difference in the interest in explicit sexual stimuli between patients with SCH and healthy controls. Explicit erotic signals seem to be sexually salient to them, which indicates their interest in sexual intimacy. Our research will further determine whether individuals with SCH have impaired ability to perceive, interpret, and react to signals of sexual interest. The implications of our findings could lead to a formulation of sexual remediation strategies. The study was supported by the Czech Health Research Council, no. NU21J-04-00024 and the Charles University, Fac Med1, GAUK no. 56123. Disclosure No.

Effect of endometrial injury on pregnancy outcomes in infertile women undergoing intrauterine insemination.

One of the most common treatments for infertility is intrauterine insemination (II). The objective of this study was to determine the effect of endometrial injury on pregnancy outcomes in unexplained infertility in women undergoing II. In this randomized clinical trial, 122 women with unexplained infertility who were referred to Shariati Hospital from 2018 to 2020 were enrolled. They underwent ovulation induction using letrozole and gonadotropins. On day 9 of stimulation, they were randomly assigned to two similar groups of the same size. The first group underwent endometrial local injury by pipelle endometrial sampling, and the second group (control group) received no intervention. Only 1 II cycle was performed for each patient. Patients with negative pregnancy outcomes were followed up for 3 months. Endometrial thickness, dominant follicle count, chemical and clinical pregnancy rate, miscarriage rate, and spontaneous pregnancy rate after the II cycle were compared between the two groups. Endometrial thickness, dominant follicle count, chemical and clinical pregnancy rate, and miscarriage rate in the same II cycle were not different between the two groups (p>0.05). However, the spontaneous pregnancy rate after the II cycle was significantly higher in the endometrial injury group (p=0.02). Endometrial injury increases pregnancy rates in later cycles but not in the same II cycle.

Vehicle group identification and evolutionary analysis using vehicle trajectory data

Vehicles often move forward in groups on the highways, especially when speed and density are high simultaneously. Abnormal maneuvers of a vehicle in a group influence multiple vehicles surrounding it, potentially leading to traffic accidents. We propose an approach to identify vehicle groups and analyse the factors influencing their evolutions using vehicle trajectory data. The proposed approach quantifies the interactions between neighboring vehicles based on the potential energy field, represents the interactive relationships among multiple vehicles using a multi-vehicle interaction network, and adopts the process of sub-network segmentation to identify vehicle groups. A random-parameter logistic regression (RPLG) model is developed to examine the influence of vehicle group features on vehicle group split. The effectiveness of the proposed approach is demonstrated in a case study using a real-world dataset. The case study reveals that: (1) the interaction strengths between vehicles tend to increase with increasing speed, (2) the interaction strength between a vehicle and its preceding vehicle is the largest, while the interaction strengths between a vehicle and its vehicles on its sides are the lowest, and (3) higher longitudinal and lateral speeds, larger fluctuations in longitudinal speeds and accelerations, larger group size, larger distances between vehicles, more lanes occupied by a vehicle group, and higher vehicle interactions significantly increase the probability of vehicle group split. The findings of this study can potentially support the traffic management and development of autonomous driving technology in connected vehicle environments.

Early social complexity influences social behaviour but not social trajectories in a cooperatively breeding cichlid fish.

Social competence-defined as the ability to optimize social behaviour according to available social information-can be influenced by the social environment experienced in early life. In cooperatively breeding vertebrates, the current group size influences behavioural phenotypes, but it is not known whether the group size experienced in early life influences behavioural phenotypes generally or social competence specifically. We tested whether being reared in large versus small groups for the first two months of life affects social behaviours, and associated life-history traits, in the cooperatively breeding cichlid Neolamprologus pulcher between the ages of four and twelve months. As we predicted, fish raised in larger and more complex groups showed higher social competence later in life. This was shown in several ways: they exhibited more, and earlier, submissive behaviour in response to aggression from a dominant conspecific, and-in comparison to fish raised in small groups-they exhibited more flexibility in the expression of submissive behaviour. By contrast, there was no evidence that early social complexity, as captured by the group size, affects aggression or exploration behaviour nor did it influence the propensity to disperse or show helping behaviour. Our results emphasize the importance of early-life social complexity for the development of social competence.

Travel patterns and multi-destinations of visitors: Toward marine park management strategies

Understanding visitor movements within Marine Protected Areas (MPAs) is crucial for their management. This study identifies the choice of destination and heterogeneity of visitors to Hikkaduwa National Park (HNP) in Sri Lanka and explores how this information could be used to inform MPA management. Face-to-face interviews were completed with 241 visitor groups. Results revealed that single-destination visits were undertaken by 70.1% of survey respondents, with 29.9% multi-destination visits. The trip duration, group size, distance between origin and first destination, and recreation time influenced multi-destination visits. Visits also varied based on the frequency of visits, length of stay, and on-site recreation diversity. The findings of this study suggest improving available multiple recreational opportunities to ensure the viability of destination, and recreation in HNP should be managed sustainably to promote recovery of the degraded coral reef and to ensure the long-term survival of the marine ecosystem while increasing contribution to the economy.

Heritability of cognitive performance in wild Western Australian magpies.

Individual differences in cognitive performance can have genetic, social and environmental components. Most research on the heritability of cognitive traits comes from humans or captive non-human animals, while less attention has been given to wild populations. Western Australian magpies (Gymnorhina tibicen dorsalis, hereafter magpies) show phenotypic variation in cognitive performance, which affects reproductive success. Despite high levels of individual repeatability, we do not know whether cognitive performance is heritable in this species. Here, we quantify the broad-sense heritability of associative learning ability in a wild population of Western Australian magpies. Specifically, we explore whether offspring associative learning performance is predicted by maternal associative learning performance or by the social environment (group size) when tested at three time points during the first year of life. We found little evidence that offspring associative learning performance is heritable, with an estimated broad-sense heritability of just -0.046 ± 0.084 (confidence interval: -0.234/0.140). However, complementing previous findings, we find that at 300 days post-fledging, individuals raised in larger groups passed the test in fewer trials compared with individuals from small groups. Our results highlight the pivotal influence of the social environment on cognitive development.

Coral mariculture using abandoned abalone farming ponds in northeastern Taiwan

Stony corals are ecologically and economically important marine organisms. Coral aquaculture is essential to provide live coral materials for the marine ornamental trade, reef restoration programs, and environmental education. This study sought to establish coral farms in Taiwan. To culture corals, we adopted an abandoned abalone farming pond built along the northeastern coast of Taiwan, and investigated whether it is possible to propagate corals in this artificial environment. Stainless steel underwater tables were anchored to the pond floor, and fragments of Acropora tumida, Pocillopora damicornis, Stylophora pistillata, Favites pentagona, and Porites lobata were cultured on the tables for one year. Environmental factors in the pond were also monitored. The mean surface temperature was 23.07 °C, ranging from >30 °C in summer to 18 °C in winter. The mean salinity and pH were about 35 ppt and 8.14, respectively. Survivorship of these five species after one year ranged from 100% to 67%, with a 1.37–1.51-fold increase in weight and a 3.22–3.38-fold increase in area, demonstrating that although environmental factors fluctuate depending on the season and weather, long-term and stable asexual propagation of corals is feasible in the pond. For further optimization of culture conditions, the effects of initial fragment size for culture on subsequent survival and growth were investigated. Fragments of 3 sizes (1.5, 3.0, and 4.5 cm) were prepared from parental colonies of A. tumida, P. damicornis, and S. pistillata and cultured for 6 months by hanging them under the table. There were no significant differences in survivorship among these sizes. Differences were observed in biomass (weight) increase. In A. tumida, 3-cm fragments showed significantly more weight gain than other lengths, while 1.5-cm fragments showed a significant weight increase in P. damicornis. In S. pistillata, no significant difference in weight increase was observed among size groups, suggesting the necessity to optimize the initial fragment size for culture for each species before mass culture. Histological analysis showed that mature gametes were formed in some cultured corals, suggesting that sexual propagation may also be possible in the future. The established coral farm, which is culturing >4000 coral fragments now, will be able to support not only basic and applied coral research, but also sustainable reef development and marine ornamental trade.

When selection pays: Structured public goods game with a generalized interaction mode.

The public goods game is a broadly used paradigm for studying the evolution of cooperation in structured populations. According to the basic assumption, the interaction graph determines the connections of a player where the focal actor forms a common venture with the nearest neighbors. In reality, however, not all of our partners are involved in every game. To elaborate this observation, we propose a model where individuals choose just some selected neighbors from the complete set to form a group for public goods. We explore the potential consequences by using a pair-approximation approach in a weak selection limit. We theoretically analyze how the number of total neighbors and the actual size of the restricted group influence the critical enhancement factor where cooperation becomes dominant over defection. Furthermore, we systematically compare our model with the traditional setup and show that the critical enhancement factor is lower than in the case when all players are present in the social dilemma. Hence, the suggested restricted interaction mode offers a better condition for the evolution of cooperation. Our theoretical findings are supported by numerical calculations.

Targeting Breast Cancer with N-Acetyl-D-Glucosamine: Integrating Machine Learning and Cellular Assays for Promising Results.

Breast cancer is a common cancer with high mortality rates. Early diagnosis is crucial for reducing the prognosis and mortality rates. Therefore, the development of alternative treatment options is necessary. This study aimed to investigate the inhibitory effect of N-acetyl-D-glucosamine (D-GlcNAc) on breast cancer using a machine learning method. The findings were further confirmed through assays on breast cancer cell lines. MCF-7 and 4T1 cell lines (ATCC) were cultured in the presence and absence of varying concentrations of D-GlcNAc (0.5 mM, 1 mM, 2 mM, and 4 mM) for 72 hours. A xenograft mouse model for breast cancer was established by injecting 4T1 cells into mammary glands. D-GlcNAc (2 mM) was administered intraperitoneally to mice daily for 28 days, and histopathological effects were evaluated at pre-tumoral and post-tumoral stages. Treatment with 2 mM and 4 mM D-GlcNAc significantly decreased cell proliferation rates in MCF-7 and 4T1 cell lines and increased Fas expression. The number of apoptotic cells was significantly higher than untreated cell cultures (p < 0.01 - p < 0.0001). D-GlcNAc administration also considerably reduced tumour size, mitosis, and angiogenesis in the post-treatment group compared to the control breast cancer group (p < 0.01 - p < 0.0001). Additionally, molecular docking/dynamic analysis revealed a high binding affinity of D-GlcNAc to the marker protein HER2, which is involved in tumour progression and cell signalling. Our study demonstrated the positive effect of D-GlcNAc administration on breast cancer cells, leading to increased apoptosis and Fas expression in the malignant phenotype. The binding affinity of D-GlcNAc to HER2 suggests a potential mechanism of action. These findings contribute to understanding D-GlcNAc as a potential anti-tumour agent for breast cancer treatment.

Survival does not differ by annual center transplant volume-A Pediatric Heart Transplant Society Registry study.

There are conflicting data regarding the relationship between center volume and outcomes in pediatric heart transplantation. Previous studies have not fully accounted for differences in case mix, particularly in high-risk congenital heart disease (CHD) groups. We aimed to evaluate the relationship between center volume and outcomes using the Pediatric Heart Transplant Society (PHTS) Registry and explore how case mix may affect outcomes. A retrospective cohort study of all pediatric patients in the PHTS Registry who received a heart transplant from 2009 to 2018 was performed. Centers were divided into 5 groups based on average yearly transplant volume. The primary outcome was time to death or graft loss and outcomes were compared using Kaplan-Meier analysis. There were 4583 cases among 55 centers included. There was no difference in time to death or graft loss by center volume in the entire cohort (p = .75), in patients with CHD (p = .79) or in patients with cardiomyopathy (p = .23). There was also no difference in time to death or graft loss by center size in patients undergoing transplant after Norwood, Glenn or Fontan (log rank p = .17, p = .31, and p = .10 respectively). There was a statistically significant difference in outcomes by center size in the positive crossmatch group (p < .0001), though no discernible pattern related to high or low center volume. Outcomes are similar among transplant centers of all sizes, including for high-risk patient groups with CHD. Future work is needed to understand how patient-specific risk factors may vary among centers of various sizes and whether this influences patient outcomes.

Impact of biologics on lung hyperinflation in patients with severe asthma

BackgroundIn asthma, inflammation affects both the proximal and distal airways and can cause significant hyperinflation, which is thought to be a major cause of dyspnea. MethodsThis is a retrospective observational study evaluating the effect of three months of treatment with different biologic drugs (benralizumab, dupilumab and omalizumab) on pulmonary hyperinflation in a cohort of patients with severe asthma already receiving regular triple inhaled therapy. Changes in RV, RV/TLC ratio, FRC and FRC/TLC ratio were the primary efficacy measures. Secondary outcomes included FEV1, FVC, FEV1/FVC ratio, IC, IC/TLC ratio, asthma control test, the percentage of eosinophils in the blood and fractional FENO. ResultsBenralizumab led to significant changes (p < 0.001) in RV, RV/TLC, FRC, and FRC/TLC. Dupilumab demonstrated a notable reduction in RV (p = 0.017) and RV/TLC (p = 0.002), but the decreases in FRC and FRC/TLC were merely numerical and not as pronounced as those induced by benralizumab. Omalizumab's positive impact on RV (p = 0.057) and RV/TLC (p = 0.085), as well as FRC (p = 0.202) and FRC/TLC (p = 0.096), was also predominantly numerical, with a tendency towards efficacy, albeit excluding the effect on FRC. Treatment with biologics resulted in improvements in all other lung function parameters assessed and a decrease in FENO levels. ConclusionThis study, although limited by small sample size, lack of a placebo control, and unbalanced group sizes, suggests that biological agents are effective in reducing lung hyperinflation even after a relatively short treatment.

Bond strength model between steel rebar and ultrahigh performance concrete containing coarse aggregates

To clarify the bond performance between steel rebar and ultrahigh performance concrete containing coarse aggregates (UHPC-CA), a total of 33 pull out specimens was cast. The effects of coarse aggregate particle size, coarse aggregate content, and steel fiber content on the failure modes and bond stress-slip curves of the specimens were studied. Based on the virtual crack model, considering the tensile contribution of steel fibers and the bridging effect of coarse aggregates, a model for the bond strength between UHPC-CA and steel rebar was established. The research findings indicated that there was a corresponding matching relationship between coarse aggregate particle size and the spacing of steel rebar ribs. In the 5–8 mm particle size group, the specimens showed 7.95% and 9.01% increases in bond strength compared to the 3–5 mm and 8–10 mm particle size groups, respectively. When the coarse aggregate content of UHPC-CA was 20%, the bond strength was the highest, increasing by 11.39% compared to specimens without coarse aggregates. The bond strength first increased and then decreased with increasing steel fiber content. Excessive steel fiber content could lead to the clustering of steel fibers, reducing the effective number of steel fibers contributing to toughening. The calculated results from the established bond strength model were compared with experimental and literature results, yielding an average ratio of 0.993 and a standard deviation of 0.166. This model effectively predicts the bond strength between UHPC-CA and steel rebar.

Diversity and discrimination of large ornithopods revealed through their tracks (Lower Cretaceous, Spain): A phenetic correlation approach

Large ornithopods were frequent in the alluvial-to-coastal sedimentary systems developed during the Barremian in the Iberian Peninsula. Here, several pes track casts of large ornithopods from the Barremian Camarillas Formation of the southwestern sector of the Maestrazgo Basin (Iberian Basin, Spain) are analyzed. Two morphotypes of tracks from three different size classes are differentiated based on some morphological features, such as length of digits, the width of the “heel” pad impression, and width of the proximal part of digit III. These casts are assigned to Caririchnium isp. Morphotype 1 is represented by small to large-sized tracks, whereas Morphotype 2 by medium-sized tracks. Morphological variation seen among tracks of Morphotype 1 is interpreted to be possibly an ontogenetic variation. On the contrary, the differences seen between Morphotype 1 and 2 cannot be explained only by extramorphological causes, so might represent different trackmakers, especially when taking into account the considerable Barremian ornithopod diversity. A modified phenetic correlation is carried out between several well-preserved casts and the identified feet of Barremian ornithopods from Iberia, in order to infer the putative trackmakers. Morphotype 1 fits with the foot skeletal structure of the large styracosternan Iguanodon, including small-sized tracks that are perfectly accommodated to that of perinates of I. galvensis. Morphotype 2 matches better to the pes skeletal structure of the medium-sized Mantellisaurus. Similar two morphotypes can be also identified in other areas of the Lower Cretaceous of Europe, so, they could be tentatively produced by the two sized groups of styracosternans typical in the Early Cretaceous of Europe. Therefore, the ichnological analysis may allow differentiation of the diversity known through the direct record. In addition, the paleoecological analysis indicates a spatial niche partitioning between two size groups of styracosternans, because large-sized tracks and bones of these dinosaurs are the most common in such sediments.

Short-term chloral hydrate as an add-on treatment may improve sleep and alleviate agitation in inpatients with treatment resistant schizophrenia: a retrospective case series study.

Chloral hydrate (CH), a medication dating back to 1832, is tranquilizer and sleep promoter still used today. It remains an option for short-term insomnia therapy and sedation before medical procedures, despite its controversial safety profile. This study investigated the potential benefits of chloral hydrate addition for increasing sleep duration and reducing agitation and violence in inpatients with treatment-resistant schizophrenia (TRS). A retrospective, observational case series design was utilized, analyzing data from fourteen patients diagnosed with TRS disorders. CH addition increased the rate of full night sleep and decreased the rates of agitation and verbal and physical violence events. Notably, no adverse events including falls were reported during CH addition. CH shows some short-term benefits in improving sleep disorders and reducing violent and agitated behavior in patients with TRS. Our study has limitations due to its small sample size, retrospective design and lack of a control group. A large-scale, double-blind, randomized trial is needed to further explore the efficacy and safety of CH in psychiatric populations with TRS accompanied by agitation, violence and disturbed sleep.

Морская транспортировка нефти на экспорт с месторождений Арктики

The prospects for the development of transportation of crude oil from the Arctic shelf, incl. in the Eastern sector of the Russian Arctic are analyzed. Projects for the production and resources of hydrocarbons have been identified and mentioned ones will become the basis for the development of cargo transportation along the NSR in the medium and long term. The study of existing options for the transportation of hydrocarbons from the shelf of the Far East and the Russian Arctic showed the relevance of using schemes using shuttles and floating oil storage facilities. The expert approach identified the key groups of vessels necessary for the implementation of work on the shelf. The structure of fleet demand visualized in the article takes into account technologies for the development and maintenance of offshore hydrocarbon fields. As an example, the calculation of the required number of shuttles with transshipment through a floating oil storage facility or directly to the port of destination from an offshore ice-resistant fixed platform in key directions was made. The tanker Vasily Dinkov (Panamax type) and the tanker Gulf America (Aframax type) were used as prototypes. The key aspects that need to be taken into account when using the specified technological scheme of transportation are highlighted: ensuring year-round transportation; taking into account best practices and compatibility with existing schemes for the delivery of crude oil to the final ports of destination; optimal choice of transshipment points. It is also necessary to clarify the size groups of vessels on each of the routes and the size and type of floating oil storage facilities. Since the Arctic is a very sensitive area to the impact of the man-made environment, special attention is paid to environmental risks that increase with the intensification of navigation in the NSR water area.

Biometric analysis of food products of hybrid hypoophthalmichthys (Hypophthalmichthys spp.) to determine their nutritional value and use in the food industry

This scientific work describes research, the purpose of which was to study the spectrum of nutrition and the composition of the food lump, as studies aimed at assessing specific weight (%) of essential nutrients (glycogen, proteins, and lipids) in particular organs and tissues of different size and mass groups of the hybrid of Silver carp and Bighead carp in ponds and reservoirs in different periods of the year. In 2018, and 2019, the juveniles of the hybrid of Silver carp and Bighead carp in ponds and reservoirs mainly consumed phytoplankton organisms (from 30 to 90% by mass), among which green, diatom, and euglena algae predominated by mass in the food group. Zooplankton occupied an insignificant place in fish nutrition (up to 5%), even though its quantity and biomass were sufficient in reservoirs. The hybrid of Silver carp and Bighead carp does not hurt zooplankton communities, so it can be included in the stocking volume of Silver carp. The feeding spectrum and rations of different groups of Silver carp and Bighead carp in ponds and reservoirs had a well-defined seasonal character related to the composition of feed objects. In all size and mass groups of the hybrid of silver and bighead carp from ponds and reservoirs in 2018, and 2019, mostly satisfactory values of general metabolism indicators were found – glycogen, proteins, and lipids in the liver, gills, and muscles of fish. The difference found in the availability of essential nutrients in the body of the studied fish indicates a change in the intensity and direction of their metabolic processes.

Interplay of cooperative breeding and predation risk on egg allocation and reproductive output.

Predation risk can influence behavior, reproductive investment, and, ultimately, individuals' fitness. In high-risk environments, females often reduce allocation to reproduction, which can affect offspring phenotype and breeding success. In cooperative breeders, helpers contribute to feed the offspring, and groups often live and forage together. Helpers can, therefore, improve reproductive success, but also influence breeders' condition, stress levels and predation risk. Yet, whether helper presence can buffer the effects of predation risk on maternal reproductive allocation remains unstudied. Here, we used the cooperatively breeding sociable weaver Philetairus socius to test the interactive effects of predation risk and breeding group size on maternal allocation to clutch size, egg mass, yolk mass, and yolk corticosterone. We increased perceived predation risk before egg laying using playbacks of the adults' main predator, gabar goshawk (Micronisus gabar). We also tested the interactive effects of group size and prenatal predator playbacks on offspring hatching and fledging probability. Predator-exposed females laid eggs with 4% lighter yolks, but predator-calls' exposure did not clearly affect clutch size, egg mass, or egg corticosterone levels. Playback-treatment effects on yolk mass were independent of group size, suggesting that helpers' presence did not mitigate predation risk effects on maternal allocation. Although predator-induced reductions in yolk mass may decrease nutrient availability to offspring, potentially affecting their survival, playback-treatment effects on hatching and fledging success were not evident. The interplay between helper presence and predator effects on maternal reproductive investment is still an overlooked area of life history and physiological evolutionary trade-offs that requires further studies.

Boosting constrained teaching–learning based optimization algorithm through group discussion

Teaching–learning based optimization algorithm (TLBO) is an efficient population-based nature-inspired meta-heuristic designed initially to solve unconstrained optimization problems. TLBO being a swam intelligence based algorithm is renowned for fast convergence. This characteristic, however, occasionally causes it to converge too soon to a non-globally optimal solution. Group discussion techniques are used in educational institutions all over the world to help participants to exchange ideas and information and to improve their skills. This work imitates the outlined strategy, therefore innovating TLBO. Here, a group of virtual students is selected corresponding to each student in the learner phase of TLBO to produce diversity in the population and to balance the exploration and exploitation capabilities of it, hence reducing the likelihood of early convergence. GTLBO stands for the new algorithm that incorporates group discussion. It is essential to incorporate some constraint handling techniques (CHTs) into the TLBO framework in order to handle constrained optimization problems (COPs). The most recent, effective, and enhanced version of the widely used CHT stochastic ranking (SR) is called hybrid stochastic ranking (HSR). HSR is added to the GTLBO structure as a selection operator for managing COPs; the resulting setup is referred to as HSR-GTLBO. Additionally, the suggested algorithm’s group size for discussion is sensitive, resulting in a number of constrained variants. The efficacy of these variations is assessed with the suit CEC 2017’s constrained problems. In conformity with the parameters settlement, comparison, and ranking criteria of CEC 2017, the simulation results of the proposed versions are compared and ranked using the most advanced state-of-the-art algorithms. As a result, in the competition, the newly developed HSR-GTLBO variants placed first, second, and third.

Testing high-dimensional multinomials with applications to text analysis

Abstract Motivated by applications in text mining and discrete distribution inference, we test for equality of probability mass functions of K groups of high-dimensional multinomial distributions. Special cases of this problem include global testing for topic models, two-sample testing in authorship attribution, and closeness testing for discrete distributions. A test statistic, which is shown to have an asymptotic standard normal distribution under the null hypothesis, is proposed. This parameter-free limiting null distribution holds true without requiring identical multinomial parameters within each group or equal group sizes. The optimal detection boundary for this testing problem is established, and the proposed test is shown to achieve this optimal detection boundary across the entire parameter space of interest. The proposed method is demonstrated in simulation studies and applied to analyse two real-world datasets to examine, respectively, variation among customer reviews of Amazon movies and the diversity of statistical paper abstracts.