Overlap Index Research Articles

OVERLAPPING TRADE FLOWS AND POTENTIALS FOR INTRA-TRADE EXPANSION IN AFRICA: THE CASE OF NIGERIA’S AGRICULTURAL TRADE

African countries' endorsement of the African Continental Free Trade Area (AfCFTA) agreement framework has been regarded as a potential game-changer for intra-African trade and key to unlocking sustained economic growth and development. The euphoria surrounding this proposed introduction of a single continental market for goods and services, with free movement of businesses, persons, and investments, is closely linked to the positive relationship between trade and development as documented in the literature. However, it needs to be clarified from the literature what role overlapping trade flows may play in limiting the potential of the AfCFTA to boost intra-trade in Africa. This paper constructs trade overlap and trade expansion indices between Nigeria and selected African countries to investigate the scope for expansion of agricultural trade between Nigeria and the selected trading partners. The study finds the existence of considerable trade overlap and export expansion potential for Cassava among other agricultural products, between Nigeria and Equatorial Guinea, Guinea Bissau, Mauritania, and Sierra Leone. The study then opines that any overlapping trade flows that currently exist in the trade of Cassava between the selected partners can be redirected following the expected removal of customs tariffs once the AfCFTA is fully implemented.

Niche and Interspecific Association of Dominant Tree Species in Spruce–Fir Mixed Forests in Northeast China

This study focuses on the natural coniferous and broad-leaved mixed forest dominated by Picea asperata and Abies fabri in the Jingouling Forest Farm of Northeast China. Specifically, we place emphasis on examining the effects of different thinning intensities. By comparing the niche characteristics and interspecific associations of dominant tree species under various thinning intensity conditions, our aim is to gain deeper insights into the patterns of resource utilization by species and the interplay of tree species in the forest canopy. Based on plot survey data, analysis methods such as niche breadth, niche overlap index, Pearson correlation coefficient, and Spearman’s rank correlation coefficient were used to analyze the niche and interspecific relationship characteristics of the dominant tree species in the community. The results indicate that among the four selective cutting intensities, the tree species with the highest importance value in all cases is Abies fabri, with an average importance value of 30.29%. Additionally, Picea asperata exhibits the widest niche breadth among the tree species, with a value of 4.59. The selective thinning in this study resulted in a reduction of average species niche overlap in the community compared to the control plots. There were both positive and negative interspecies associations observed, but they were statistically insignificant. Few pairs showed significant correlations, with the positive-to-negative ratio of Pearson coefficients decreasing as the selective cutting intensity increased. The Spearman rank correlation analysis revealed a positive-to-negative ratio exceeding one for species pairs in the community under both light and heavy-cutting conditions, with no significant negative correlations observed. In summary, selective cutting disturbance can effectively increase the importance value of the dominant tree species, Abies fabri, in the community. However, it leads to a reduction in the niche breadth of all tree species present in the forest. Moderate selective cutting is considered a more suitable intensity, as it promotes the maintenance of biodiversity and yields higher forest management benefits in the mixed forest of Picea asperata and Abies fabri in Northeast China.

Lesser kestrels of the same colony do not overwinter together.

Migratory connectivity describes the linkage between breeding and nonbreeding sites, having major ecological implications in birds: 1 season influence the success of an individual or a population in the following season. Most studies on migratory connectivity have used large-scale approaches, often considering regional populations, but fine-scale studies are also necessary to understand colony connectivity. The lesser kestrel Falco naumanni, an insectivorous migratory raptor which form colonies during the breeding period, was considered to have strong connectivity based on regional populations. However, no small-scale studies on migratory connectivity have been conducted. Therefore, we GPS (Global Positioning System)-tracked 40 adult lesser kestrels from 15 different Spanish breeding colonies, estimating the overlap index between home ranges and the distance between their centroids. It was found that lesser kestrels from the same breeding colony placed their nonbreeding areas at 347 ± 281 km (mean ± standard deviation) away from each other (range = 23-990), and their home ranges overlapped by 38.4 ± 23.6%. No differences between intra-colony and inter-colony metrics were found, which suggests that lesser kestrels from the same breeding cluster do not overwinter together, but they spread out and mixed independently of the colony belonging throughout the nonbreeding range of the species. Ultimately, this study highlights the importance of performing connectivity studies using fine-scale approaches.

Niche and interspecific association of dominant tree species in karst forest of Junzi Mountain, Eastern Yunnan, China.

To understand the interspecific relationships of tree species in the karst forest of Junzi Mountain in Eas-tern Yunnan, we evaluated the niche and interspecific association of dominant tree species based on field survey plot data with the combining approaches of niche determination, χ2 test, association coefficient (AC), and Spearman rank correlation test. The results showed that the niche breadth of Quercus glaucoides was the largest and that of Juglans mandshurica was the smallest. The ranking of niche breadth was more consistent with the ranking of frequency than with that of importance values. The degree of niche overlap was generally low, with a mean value of 0.21, suggesting a low similarity in resource utilization among tree species. The overall association of dominant tree species was significantly positive, and the ratio of positive and negative association was 1.07, indicating that the communities were at a relatively stable and the late succession stage. The χ2 test and Spearman rank correlation test for tree dominant species showed that 65.3% species pairs were not significantly associated with each other, indicating a weak interspecific association. Both association coefficient (AC) and Spearman rank correlation coefficient showed significantly positive correlations with the corresponding niche overlap index. The species pairs of Q. glaucoides-Rhamnella martini, Viburnum propinquum-Zanthoxylum myriacanthum, Cladrastis delavayi-Carrierea calycina, Z. myriacanthum-C. delavayi had strong interspecific associations and wide ecological niches, thus may have potential application value in ecological restoration of karst region in eastern Yunnan and the vicinity areas.

Tiers 1 and 2 of a German MTSS: impact of a multiple baseline study on elementary school students with disruptive behavior

IntroductionThe prevalence of disruptive behavior is increasing worldwide, affecting the learning process and classroom climate, teacher–student relationships, and peer interactions. Disruptive behavior in childhood can have detrimental effects on a child’s long-term growth and may predict similar behavior in adolescence and adulthood. Thus, it is not only contemporary education and school research that are concerned with addressing the issues of teacher workload reduction and improvement of students’ learning environment, but it is also a socially relevant issue. The Multi-tiered Systems of Supports (MTSS) effectively mitigates some of these challenges in the education system and is recognized as a successful framework.MethodsTherefore, this single-case study examined the first two tiers of an MTSS developed in Germany (Multimo) to determine the impact of its implementation on 32 students with disruptive behavior. The first hypothesis propose that the implementation of Tier 1 can effectively decrease disruptive behavior among all students and the second one that assigning students to Tier 2 can provide an additional reduction in disruptive behavior. Data analysis included multilevel analyses with piecewise-multilevel models and the overlap index, the Nonoverlap of All Pairs, based on teachers’ direct behavior rating. All analyses focused exclusively on the outcome variable of disruptive behavior, which was estimated based on teachers’ daily behavior ratings.ResultsThe results of the study showed a significant reduction of disruptive behavior in elementary school students at Tier 1. Disruptive behavior decreased at Tier 2 as well but did not show a significant change compared with Tier 1.DiscussionThe study concludes that in the context of an MTSS, the Good Behavior Game and Daily Behavior Report Card can be used together.

The Zone Overlap Index: A new measure of shared resource use in the zoo.

It is important that the environment provided in the zoo is relevant to the species being housed and its suitability be easily assessed by personnel. As shared space and resources can overlap in a zoo's enclosure a tool is required to measure the effects of such overlap between individual animals in a shared enclosure. This paper outlines the Pianka Index (PI), a tool used in ecology to quantify niche overlap, that has value in quantifying the amount of time that animals spend in shared enclosure zones. One limitation to this method, however, is that the established method of determining the PI requires division of the enclosure into equally sized zones, something that is not always relevant to a zoo enclosure. To combat this, we created a modified index, entitled the Zone Overlap Index (ZOI). This modified index is the exact mathematical equivalent of the original index when zone sizes are equal. When zone sizes are unequal, the ZOI generates higher values when animals share smaller, as opposed to larger, zones. This is because animals are more likely to share larger enclosure zones simply by chance, and shared use of smaller zones brings individuals into closer proximity with the potential for competition. To illustrate the application of the ZOI, a series of hypothetical situations were generated to reflect real-world scenarios, demonstrating how this index could be used to better understand zone occupancy overlap in the zoo.

Estimating climate-driven phenology shifts and survey availability using fishery-dependent data

Environmental changes are predicted to impact fish ecology; specifically, the phenology of spawning and larval settlement, resulting adult and larval movement, and ultimately seasonal habitat utilization. Hence, warm or cold environmental conditions may cause early or late seasonal movement among habitats. However, resource surveys are typically designed to occur at approximately the same time each year, and this mismatch in timing between survey sampling and fish movement can cause a different proportion of population biomass to be available to the survey in different years. In this study, we demonstrate an application to minimize such impacts using yellowfin sole (Limanda aspera) in the eastern Bering Sea as a case study. We employedfishery-dependent catch-and-effort (also called catch per unit effort (CPUE)) datacollected by observers on commercial vessels, which covered the months of March-October (whereas survey data were limited to June-August). We built a seasonal spatio-temporal model so that seasonal distribution could be used to better explain summer survey availability and movement timing as impacted by interannual temperature changes. Our results highlight (i) spawning movement phenology occurs earlier during warm years than cold years, (ii) spatial distribution is more constrained and biomass is lower during cold years than warm years, (iii) fish were more available to the summer survey during warm years than cold years, and (iv) phenology differed by sex with males staying longer on the spawning grounds than females. Finally, we computed an overlap index between the survey area and fishery CPUE data to be used as a catchability covariate within the yellowfin sole stock assessment. This index confirmed the changes in relative availability of this species by year as presently used in the assessment.

Morphological characteristics influence the spatial mixing patterns of shorebirds at Shengjin Lake.

The coexistence of species with similar ecological niches is one of the core interests of community ecology research. However, how functional feeding traits, including bill size and leg length, determine the niche of mixed flocks of shorebird species has seldomly been studied, as well as, microhabitat variables affect the spatial patterns of availability and the quality of patches for wintering. From October 2016 to March 2017 at Shengjin Lake, Anhui Province, China, we recorded 226 scan samples from the different microhabitats and 93 focal animal videos of four common shorebird species: common greenshank, spotted redshank, Kentish plover, and little ringed plover. We found that the species participating in the mixed groups were different in each microhabitat. The results of the overlap index for microhabitats and foraging techniques between the species were consistent with the morphological characteristics of these species. Kentish and little ringed plovers had the highest Pianka's niche overlap index values of 0.95 and 0.98 for microhabitats and foraging techniques, respectively, whereas common greenshank and spotted redshank had values of 0.78 and 0.89, respectively. Common greenshank and spotted redshank used four foraging techniques: a single probe (PR), multiple probes (MPR), a single peck (PE), and multiple pecks (MPE). Kentish and little ringed plovers only used PE and MPE. The mean bill size, mean leg length, and mean foraging frequency were significantly associated with water depth. The mean bill size and mean leg length were both significantly correlated with the mean foraging frequency of shorebirds. The vegetated area was the most important variable for grouping among shorebirds. We concluded that the four species showed differences in their preferred microhabitats and foraging patterns. Interspecific morphological differences, including bill and leg lengths, resulted in niche differentiation. Thus, effective resource allocation by regional species was realized, and a dynamic balance was achieved by the mixed foraging species. The information on foraging behavior and habitat requirements could be useful in the management of water levels in natural areas and conservation of a diversity of wintering shorebirds.

Navigation and the efficiency of spatial coding: insights from closed-loop simulations

Spatial learning is critical for survival and its underlying neuronal mechanisms have been studied extensively. These studies have revealed a wealth of information about the neural representations of space, such as place cells and boundary cells. While many studies have focused on how these representations emerge in the brain, their functional role in driving spatial learning and navigation has received much less attention. We extended an existing computational modeling tool-chain to study the functional role of spatial representations using closed-loop simulations of spatial learning. At the heart of the model agent was a spiking neural network that formed a ring attractor. This network received inputs from place and boundary cells and the location of the activity bump in this network was the output. This output determined the movement directions of the agent. We found that the navigation performance depended on the parameters of the place cell input, such as their number, the place field sizes, and peak firing rate, as well as, unsurprisingly, the size of the goal zone. The dependence on the place cell parameters could be accounted for by just a single variable, the overlap index, but this dependence was nonmonotonic. By contrast, performance scaled monotonically with the Fisher information of the place cell population. Our results therefore demonstrate that efficiently encoding spatial information is critical for navigation performance.

Interspecies Association and Community Stability of Plants in the Core Distribution Area of Thuja sutchuenensis

The protection of endangered species is a hot topic for scholars worldwide, and interspecific association and community stability analysis are important methods with which to explore the structure and function of the endangered species community. Thuja sutchuenensis Franch. is an endangered species; however, studies on the T. sutchuenensis community remain insufficient. Here, based on the data of the plot survey of the T. sutchuenensis community in the Ta-pa Mountains and Xuebao Mountains, we analyzed the interspecific associations, niche width, and niche overlap of major species in the arborous and shrub layers, as well as community stability. The results showed that the overall interspecies association between the species of the arbor layer was non-significantly negatively associated, while the shrub layer was non-significantly positively associated. The Chi-square test results showed that the species pairs without interspecific association in the arbor layer and the shrub layer were much higher than those with significant interspecific association; in other words, the interspecific association of species in the T. sutchuenensis community was loose. The results of interspecific association coefficient analysis showed that the number of negatively associated species pairs was significantly higher than that of positive association species pairs, but Pearson’s correlation coefficient and Morisita’s niche overlap index analysis showed that the degree of competition between species in the community was small. In the arbor layer, the niche width of T. sutchuenensis was the widest, while in the shrub layer, the niche width of T. sutchuenensis was relatively high, indicating that T. sutchuenensis had a strong ability to adapt to the environment and use available resources. In addition, the intersection point of community stability (32.11, 67.89) in the vegetative community of T. sutchuenensis suggested that the community displayed a better stability. The survival strategy of T. sutchuenensis is based on its strong adaptability to the harsh environment to escape the competition among species, and this knowledge can provide a reference for the protection and restoration of endangered species.

Analysis of genomic and immune intratumor heterogeneity in linitis plastica via multiregional exome and T-cell receptor sequencing.

The molecular landscape and the intratumor heterogeneity (ITH) architecture of gastric linitis plastica (LP) are poorly understood. We performed whole-exome sequencing (WES) and T-cell receptor (TCR) sequencing on 40 tumor regions from four LP patients. The landscape and ITH at the genomic and immunological levels in LP tumors were compared with multiple cancers that have previously been reported. The lymphocyte infiltration was further assessed by immunohistochemistry (IHC) in LP tumors. In total, we identified 6339 non-silent mutations from multi-samples, with a median tumor mutation burden (TMB) of 3.30 mutations per Mb, comparable to gastric adenocarcinoma from the Cancer Genome Atlas (TCGA) cohort (P = 0.53). An extremely high level of genomic ITH was observed, with only 12.42%, 5.37%, 5.35%, and 30.67% of mutations detectable across 10 regions within the same tumors of each patient, respectively. TCR sequencing revealed that TCR clonality was substantially lower in LP than in multi-cancers. IHC using antibodies against CD4, CD8, and PD-L1 demonstrated scant T-cell infiltration in the four LP tumors. Furthermore, profound TCR ITH was observed in all LP tumors, with no T-cell clones shared across tumor regions in any of the patients, while over 94% of T-cell clones were restricted to individual tumor regions. The Morisita overlap index (MOI) ranged from 0.21 to 0.66 among multi-regions within the same tumors, significantly lower than that of lung cancer (P = 0.002). Our results show that LP harbored extremely high genomic and TCR ITH and suppressed T-cell infiltration, suggesting a potential contribution to the frequent recurrence and poor therapeutic response of this adenocarcinoma.

Feeding Habits of Dentex maroccanus and the Effect of Body Size

The feeding habits of organisms are important elements in their ecological role and are affected by several factors. The present study provides for the first time information on the diet and feeding strategy of Dentex maroccanus (Valenciennes, 1830) and examines the effects of various factors on the species' feeding activity. Various indices (vacuity index, numerical and weight proportion, frequency of occurrence, alimentary coefficient, index of relative importance, diet breadth and overlap, Shannon-Wiener index, and trophic level) were estimated. The diet of the species consisted of 18 different prey taxa. The most important prey taxon was Decapoda. The study of the feeding strategy showed the narrow width of the species. Body size was found to significantly affect the species' feeding habits. Polychaeta and Stomatopoda were found only in individuals with size ≥165 mm, Bivalvia mainly in sizes ≤120 mm, and Decapoda in the intermediate sizes. The largest individuals showed the lowest overlap with all other size groups. The trophic level increased from 3.7 in young individuals to 4.0 in larger sizes, indicating the carnivorous character of the species. The results of the present work contribute to a better knowledge of the species' feeding ecology.

Diet composition of Asiatic lions in protected areas and multi-use land matrix

Comparative studies on the diet of large felids in protected areas (PAs) and surrounding multi-use landscapes are important for their conservation. The Asiatic lion is an endangered felid distributed in Gir PA and the surrounding multi-use land matrix. Based on scat analyses, we assessed the dietary composition of Asiatic lions. The frequency of occurrence (FOO), biomass consumption model, dietary niche breadth and dietary overlap index was used to quantify diet. The Asiatic lion ate more wild prey (74%) than domestic livestock (26%) in the Gir PA. In contrast, lion diets comprised 51% wild prey and 42% domestic livestock in the multi-use land matrix. Sambar contributed most (38%) to the diet in PAs, while blue bull most (29%) in the multi-use land matrix. However, diet diversity and niche breadth were similar between these two areas. The dietary overlap in the lions' diet between these two areas was 0.52. The results suggest that large-size wild ungulates are the main prey species in Gir PA, while in the surrounding multi-use land matrix, both large wild ungulates and domestic livestock are the main prey. The present study may help future lion conservation management decisions.

Type-$(2,k)$ Overlap Indices

Automatic image detection is one of the most important areas in computing due to its potential application in numerous real-world scenarios. One important tool to deal with that is called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">overlap indices</i> . They were introduced as a procedure to provide the maximum lack of knowledge when comparing two fuzzy objects. They have been successfully applied in the following fields: image processing, fuzzy rule-based systems, decision making, and computational brain interfaces. This notion of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">overlap indices</i> is also necessary for applications in which type-2 fuzzy sets are required. In this article, we introduce the notion of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">type-<inline-formula><tex-math notation="LaTeX">$(2,k)$</tex-math></inline-formula> overlap index</i> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$k \in \lbrace 0,1,2\rbrace$</tex-math></inline-formula> ) in the setting of type-2 fuzzy sets. We describe both the reasons that have led to this notion and the relationships that naturally arise among the algebraic underlying structures. Finally, we illustrate how type- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$(2,k)$</tex-math></inline-formula> overlap indices can be employed in the setting of fuzzy rule-based systems when the involved objects are type-2 fuzzy sets.

Diet composition and interspecific niche of Taohongling Sika deer (Cervusnipponkopschi) and its sympatric Reeve's muntjac (Muntiacusreevesi) and Chinese hare (Lepussinensis) in winter (Animalia, Mammalia).

Species co-existence depends on how organisms utilize their environment and resources. Little is known about the winter diet composition and sympatric co-existence of South China sika deer and its companion species in Taohongling. In this study, high-throughput sequencing and metabarcoding trnL were used to study the diet composition and interspecific relationship including sika deer, Reeve's muntjac, and Chinese hare. Our results show that 203 genera in 90 families are contained in the diet of sika deer, 203 genera in 95 families for Reeve's muntjac, and 163 genera in 75 families for Chinese hare. Sika deer fed on Rubuschingii, Loropetalumchinense, and Euryajaponica in winter, accounting for 75.30%; Reeve's muntjac consumed mainly R.chingii, E.japonica, and Euonymusgrandiflorus, accounting for 68.80%, and Chinese hare mainly fed on R.chingii, Smilaxchina, and Rhuschinensis, accounting for 41.98%. The Shannon index showed no significant difference between groups (p > 0.05). The NMDS analysis found considerable overlap among three species. Sika deer and Reeve's muntjac consumed similar forage plants but varied greatly in Chinese hare, which occupied the widest choice in winter, resulting in higher diet breadth and increased dietary divergence, thereby reducing competition and facilitating coexistence. The diet niche overlap index among them, as represented by Pianka's index, ranging from 0.62 between sika deer and Chinese hare to 0.83 between sika deer and Reeve's muntjac, which indicated a more similar niche and potential competition in closely related species. Our findings provide a new diet perspective of three herbivores, leading to a more comprehensive understanding of resource partitioning and species coexistence.

The dominant species of natural enemies of Pentatomidae in the peak period

AbstractThis paper aims to analyse how to effectively protect and scientifically utilize the natural enemies of Pentatomidae in tea plantations in the peak period. In this paper, the spatial, quantitative and temporal relationships between Pentatomidae and its natural enemies in “Pingyangtezao”, “Wuniuzao”, “Huangshandayezhong”, “Anjibaicha”,”Longjing 43″ and “Nongkangzao” tea gardens in Hefei, China were comprehensively compared and analyzed with the methods of geostatistical analysis, gray system analysis and temporal ecotone overlap index analysis. According to the size of the closeness index, the top three natural enemies with the largest sum of spatial, quantitative, and temporal closeness indexes in the six tea gardens were Clubiona japonicola (X7, 16.514), Oxyopes sertatus (X5, 16.390) and Xysticus ephippiafus (X2, 16.270). The size of the ratio between the number of Pentatomidae individuals and natural enemies largely determines whether the natural enemies follow Pentatomidae pests closely or not. The better the growth of tea plantations and the richer the diversity of pest species, the more accurately the predation preference of natural enemies can be reflected. In the control of Pentatomidae, specific analysis should be made according to the occurrence characteristics of target pests in different tea plantations and the basic attributes of tea plantations (species, growth, population characteristics of natural enemies and pests, etc.) in order to scientifically utilize its natural enemies.

Patterns of coexistence between two mesocarnivores in presence of anthropogenic disturbances in Western Himalaya

Species' coexistence depends on species-specific resource utilization in a given habitat. Human disturbances in this context can constrain the realized niche by altering their community dynamics. In this study, we considered Western Himalaya as a case study to test the hypothesis that human disturbances influence mesocarnivore coexistence patterns. We regarded red fox and leopard cat as the focal species and assessed the coexistence patterns in low and high human disturbance areas in three dimensions: spatial, temporal, and dietary habit. We used camera trap detections and mitochondrial DNA-based species identification of fecal samples. We used generalized linear mixed-effect modelling (GLMM), activity overlap, Levin's niche breadth, and Pianka's overlap index to capture the spatial, temporal, and dietary interactions respectively. We found that red fox and leopard cat coexisted by spatial segregation in low human disturbance area, whereas dietary segregation was the means of coexistence in high human disturbance area. We observed a broader dietary breadth for red fox and a narrower for leopard cat in high human disturbance area. The altered coexistence pattern due to differential human disturbances indicates intensive anthropogenic activities adjacent to natural forests. It can link to increased opportunities for shared spaces between mesocarnivores and humans, leading to future disease spread and conflicts. Our study contributes to scant ecological knowledge of these mesocarnivores and adds to our understanding of community dynamics in human-altered ecosystems. The study elucidates the need for long-term monitoring of wildlife inhabiting interface areas to ensure human and wildlife coexistence.

Real-Time Computer Vision for Tree Stem Detection and Tracking

Object detection and tracking are tasks that humans can perform effortlessly in most environments. Humans can readily recognize individual trees in forests and maintain unique identifiers during occlusion. For computers, on the other hand, this is a complex problem that decades of research have been dedicated to solving. This paper presents a computer vision approach to object detection and tracking tasks in forested environments. We use a state-of-the-art neural network-based detection algorithm to fit bounding boxes around individual tree stems and a simple, efficient, and deterministic multiple object tracking algorithm to maintain unique identities for stems through video frames. We trained the neural network object detector on approximately 3000 ground-truth bounding boxes of ponderosa pine trees. We show that tree stem detection can achieve an average precision of 87% using a Jaccard overlap index of 0.5. We also demonstrate the robustness of the tracking algorithm in occlusion and enter–exit–re-enter scenarios. The presented algorithms can perform object detection and tracking at 49 frames per second on a consumer-grade graphics processing unit.

Wild Felid Diversity, Space Use and Activity Patterns in the Eastern Himalaya, India

Species with similar resource requirements cannot coexist for long. To facilitate co-existence, carnivores adapt different strategies to partition the available resources in space and time. In high-altitude ecosystems with limited resources the operation becomes complex. We assessed species diversity and spatio-temporal resource partitioning among felid species inhabiting the intricate habitats of Khangchendzonga Biosphere Reserve (KBR), Eastern Himalaya. We used systematic camera trap surveys along with abundance and overlap indices to generate information on their space use and activity patterns. We recorded six species of felids belonging to five genera, including four species of global conservation importance. The differential use of space by felids was observed with respect to the habitat types determined by sharp altitudinal gradients with varied levels of spatial and altitudinal overlap. Maximum overlap was observed among Asiatic golden cat Catopuma temminckii, jungle cat Felis chaus and clouded leopard Neofelis nebulosa. The felids had distinct activity profiles from one other, particularly between golden cat and leopard cat Prionailurus bengalensis. Pianka’s index also provided weak evidence for temporal overlap among species. The overall results indicate that habitat heterogeneity facilitates primary separation at the spatial scale, although species are also segregated temporally. Golden cat was the most adaptive felid in the area, depicting a peculiar pattern of spatio-temporal segregation with other species. We suspect either intense competition or dietary segregation among some species, and propose a further investigation of their diet and the activity patterns of their prey. The study presents an early template of carnivore community organization in resource-scarce high-altitude environments, thus, offering huge ecological and conservation significance.

Set-based extended quasi-overlap functions

Overlap functions, as a class of not necessarily associative novel aggregation functions, have played an important role in the relevant theory and applications involving fuzzy sets and systems. Recently, extension study has become a hot topic in the theoretical research of overlap functions, especially for the so-called quasi-overlap functions. In this paper, we investigate the set-based extended quasi-overlap functions, which are one kind of set-based extended aggregation functions proposed by Mesiar et al. lately. Specifically, after introducing the definition of set-based extended quasi-overlap functions, we study some of their elementary properties. Furthermore, we give two equivalent characterizations of set-based extended quasi-overlap functions by means of mappings from the set composed by all finite subsets of unit closed interval with no repetition of elements to unit closed interval and 0,1-aggregation functions recently proposed by the author, respectively. In particular, it is shown that the family of set-based extended quasi-overlap functions is closed to convex combination and that the repetition of values in the input vectors to be aggregated and adding any value between its minimum and maximum values have no effect on the output value under the aggregation of set-based extended quasi-overlap functions. The obtained results afford theoretical basis for more potential applications of quasi-overlap functions in real problems, especially when there are more than two classes or objects in fuzzy context or fuzzy sets for which we need to measure the degree of overlapping or generate overlap indices.