Telemetry tails: a practical method for attaching animal-borne devices to small vertebrates in the field

Context. Continued miniaturisation of tracking technology increases its utility in animal applications. However, species morphology often dictates the type of animal-borne device (ABD) that can be used, and how it is attached. The morphology of species within Peramelemorphia preclude them from the standard collar attachment of ABDs for terrestrial mammals. Aims. This paper describes a method for the tail-mount attachment of ABDs, and deployment results for Peramelemorphia across arid, semi-arid and temperate Australia to (a) test the performance of attachments and ABDs in the field and (b) discuss the animal welfare considerations for this attachment method. Methods. Tail-mount attachment of ABDs were field-tested on a total of 80 greater bilbies (Macrotis lagotis), and 14 long-nosed bandicoots (Perameles nasuta). Key results. Time to natural detachment (TTND) was between 2 and 52 days, with 65.74% (142 of 216) remaining on until manual removal. For ABDs that were manually removed, attachments were retained for up to 94 days. The method used for tail-mount attachment of ABDs to long-nosed bandicoots resulted in significantly shorter TTND compared with the method used for bilbies, and environmental factors (high temperatures and rainfall) had a negative effect on TTND. Tail-mount attached global positioning system (GPS) sensors collected large quantities of accurate data, with a maximum fix success rate of 83.38%. Damage to GPS (antenna breakage and water ingress) during deployment, however, impacted performance. In environments with frequent rainfall and waterlogged soils, the tape on a small proportion (6.25%) of (n = 192)attachments to bilbies caused tail injury. All injuries were resolvable, with most requiringminimal to no veterinary intervention. Key conclusions. Attachment longevity can be affectedby how the ABD is mounted to the tail, the species and the deployment environment. Theenvironment can also affect which adhesive tapes are suitable for ABD attachment. However, thismethod is highly modifiable, practical for field application and can have long retention timesrelative to other temporary methods. Implications. This ABD tail-mount attachment methodadds another tool to the telemetry tool-kit, with all the benefits of a low-tech, low-cost, passivedrop-off type attachment. This method has demonstrated practicality for Peramelemorphia, withpotential application to other suitable small vertebrates

Spatial and temporal overlaps between leopards (Panthera pardus) and their competitors in the African large predator guild

Understanding the mechanisms facilitating coexistence within species assemblages is a key consideration for conservation as intact assemblages are necessary for maintaining full ecosystem function. The African large predator guild represents one of the few remaining functionally intact large predator assemblages on Earth, and as such, represents a unique study system to understand competitive interactions. Yet, relatively little is known of the coexistence mechanisms between some of its intermediately sized members, particularly leopards (Panthera pardus). Here, we use overlapping spatio‐temporal activity and GPS data on lions (Panthera leo), leopards, African wild dogs (Lycaon pictus) and cheetahs (Acinonyx jubatus) to examine spatial interactions and temporal partitioning between leopards and other guild members in northern Botswana. We found that at the population level, male leopard space use and activity patterns were largely unaffected by intraguild competitors. Leopards showed minimal movement coherence with competitors (avoidance or attraction) when moving through areas of home ranges shared with intraguild species. Moreover, we found evidence to support the hypothesis that guild species’ activity patterns are primarily driven by light availability rather than predator avoidance. Our results suggest predator avoidance has a limited impact on broad‐scale leopard spatio‐temporal niches, with aspects of the leopards’ ecology and life history likely facilitating its ability to thrive in close proximity to competitors. Considered alongside other studies, our results suggest that landscape‐level approaches to conservation may be suitable for aiding leopard conservation

Factorizations of Elements in Noncommutative Rings: A Survey

We survey results on factorizations of non zero-divisors into atoms (irreducible elements) in noncommutative rings. The point of view in this survey is motivated by the commutative theory of non-unique factorizations. Topics covered include unique factorization up to order and similarity, 2-firs, and modular LCM domains, as well as UFRs and UFDs in the sense of Chatters and Jordan and generalizations thereof. We recall arithmetical invariants for the study of non-unique factorizations, and give transfer results for arithmetical invariants in matrix rings, rings of triangular matrices, and classical maximal orders as well as classical hereditary orders in central simple algebras over global fields.Comment: 50 pages, comments welcom

Scent-marking strategies of a solitary carnivore: boundary and road scent marking in the leopard

Scent marking, where individuals deposit signals on objects in the environment, is a common form of chemical signalling in mammals and is thought to play a critical role in maintaining social organisation within wide-ranging, spatially-dispersed populations. Senders, however, can incur scent marking costs through mark production, time investment in patrolling and depositing/maintaining mark sites, and increased risk of detection by predators and prey. To mitigate these costs, senders can adapt spatial patterns of scent marking to increase the probabilities of their scent marking being encountered by intended receivers. Relatively little, however, is known of the spatial scent marking placements of many wide-ranging carnivore species, with most studies focussing on scent mark form and function. Here, we use detailed observational data collected from over seven years of following individual leopards and high-resolution GPS radio collar data to investigate the spatial placements of scent marks within a leopard population in northern Botswana. We found that male leopards within our study area exhibited a boundary scent marking strategy by showing higher investments in the maintenance of marking sites in peripheral areas of their home range. We also found that leopards scent marked over four times as frequently and investigated over three times as frequently when travelling on roads than when travelling along natural routes, suggesting that roads may function as key locations for olfactory information. Compared to leopards from less productive ecosystems, such as the Kalahari, our results (1) suggest that leopards can be highly flexible in their marking strategies, with strategies impacted by the surrounding environment, and (2) provide evidence that human-modifications of the environment now play an important role in facilitating social cohesion within this solitary carnivore

Spatio-temporal factors impacting encounter occurrences between leopards and other large African predators

Encounters between individuals can have implications for a range of processes, including 24 disease transmission, information transfer, and competition. For large carnivores, 25 difficulties in directly observing individuals and historical hardware limitations of GPS 26 collars mean that relatively little is known of the spatio-temporal factors contributing to 27 encounters. The African large predator guild represents one of the few remaining 28 functionally intact guilds of large carnivores on the globe and so represents a unique 29 study system for understanding competitor interactions. We explored the drivers of male 30 leopard (Panthera pardus) encounters with lions (Panthera leo), African wild dogs (Lycaon 31 pictus) and cheetahs (Acinonyx jubatus) in the context of habitat characteristics and 32 temporal activity overlaps. Using high resolution (five minute GPS fixes) data from 48 33 large African carnivores from 2012 to 2018, we quantified encounter occurrences 34 between male leopards and other guild species and related these to habitat type (open vs 35 closed), activity overlaps, and moonlight levels. Leopards met wild dogs 4.56 ± 1.15 36 (standard error), lions 3.11 ± 0.56, and cheetahs 2.27 ± 0.73 times per month. All species 37 instigated encounters, but leopard instigated encounters with dominant competitors 38 appeared to reflect imperfect information on risk, primarily occurring within habitats with 39 limited visibility. Moreover, encounters peaked during periods of high temporal overlap, 40 suggesting that, although previous research indicates temporal activity patterns may not 41 be driven by predator avoidance, temporal overlap has implications for competitor 42 dynamics. Our results show how habitat characteristics and niche overlaps contribute to 43 encounters between competitors and provide an example of how niche shifts within 44 competitor assemblages can impact competition between species

Enrichment analysis of Alu elements with different spatial chromatin proximity in the human genome

Transposable elements (TEs) have no longer been totally considered as “junk DNA” for quite a time since the continual discoveries of their multifunctional roles in eukaryote genomes. As one of the most important and abundant TEs that still active in human genome, Alu, a SINE family, has demonstrated its indispensable regulatory functions at sequence level, but its spatial roles are still unclear. Technologies based on 3C(chromosomeconformation capture) have revealed the mysterious three-dimensional structure of chromatin, and make it possible to study the distal chromatin interaction in the genome. To find the role TE playing in distal regulation in human genome, we compiled the new released Hi-C data, TE annotation, histone marker annotations, and the genome-wide methylation data to operate correlation analysis, and found that the density of Alu elements showed a strong positive correlation with the level of chromatin interactions (hESC: r=0.9, P<2.2×1016; IMR90 fibroblasts: r = 0.94, P < 2.2 × 1016) and also have a significant positive correlation withsomeremote functional DNA elements like enhancers and promoters (Enhancer: hESC: r=0.997, P=2.3×10−4; IMR90: r=0.934, P=2×10−2; Promoter: hESC: r = 0.995, P = 3.8 × 10−4; IMR90: r = 0.996, P = 3.2 × 10−4). Further investigation involving GC content and methylation status showed the GC content of Alu covered sequences shared a similar pattern with that of the overall sequence, suggesting that Alu elements also function as the GC nucleotide and CpG site provider. In all, our results suggest that the Alu elements may act as an alternative parameter to evaluate the Hi-C data, which is confirmed by the correlation analysis of Alu elements and histone markers. Moreover, the GC-rich Alu sequence can bring high GC content and methylation flexibility to the regions with more distal chromatin contact, regulating the transcription of tissue-specific genes

<Book Reviews> Ingemar Fagerlind and Lawrence J Saha Education and National Development : A Comparative Perspective

textabstractVarious modeling methods have been proposed to estimate the potential predictive ability of polygenic risk variants that predispose to various common diseases. However, it is unknown whether differences between them affect their conclusions on predictive ability. We reviewed input parameters, assumptions and output of the five most common methods and compared their estimates of the area under the receiver operating characteristic (ROC) curve (AUC) using hypothetical data representing effect sizes and frequencies of genetic variants, population disease risk and number of variants. To assess the accuracy of the estimated AUCs, we aimed to reproduce the AUCs of published empirical studies. All methods assumed that the combined effect of genetic variants on disease risk followed a multiplicative risk model of independent genetic effects, but they either assumed per allele, per genotype or dominant/recessive effects for the genetic variants. Modeling strategy and input parameters differed. Methods used simulation analysis or analytical formulas with effect sizes quantified by odds ratios (ORs) or relative risks. Estimated AUC values were similar for lower ORs (0.7) due to variants with strong effects, differences in estimated AUCs between methods increased. The simulation methods accurately reproduced the AUC values of empirical studies, but the analytical methods did not. We conclude that despite differences in input parameters, the modeling methods estimate similar AUC for realistic values of the ORs. When one or more variants have stronger effects and AUC values are higher, the simulation methods tend to be more accurate