No NLRP3 genetic variants were found in any of the analyzed cell types derived from 2 patients with Schnitzler syndrome without NLRP3 variants in whole blood (Table I). Because we have previously ...demonstrated that IL-1β is a pivotal mediator of the clinical signs of Schnitzler syndrome,2,5 we proceeded to investigate the functional consequences of the NLRP3 mosaic mutations on IL-1β and IL-6 production in PBMCs (see the Methods section in this article's Online Repository at www.jacionline.org). The identified variant is considered a benign polymorphism.E5 In patient 7 we detected a known missense mutation in the NACHT domain of the NLRP3 gene (c.1569C>G; p.F523L), which was previously reported as disease causing in 2 infants with NOMID/CINCA, a severe early-onset form of CAPS.E6Canonical SS, Variants located in a canonical splice site; Coding+SS, all variants located either in exonic regions or canonical splice sites; Indels, Insertions or deletions; Known variant (HGMD), variants described as pathogenic in the Human Gene Mutation Database (www.hgmd.org); Missense (phyloP >2.5),E4 highly conserved missense variants with a phyloP >2.5; Nonsense, nonsense variants; Nonsynonymous, variants leading to an amino acid change; Not seen before (in house), variants that have not been detected in 672 in-house sequenced whole exomes; Patient, patient who has undergone whole-exome sequencing; Total no. of variants, all variants detected by using whole-exome sequencing.
Summary
Activity level (the proportion of time that animals spend active) is a behavioural and ecological metric that can provide an indicator of energetics, foraging effort and exposure to risk. ...However, activity level is poorly known for free‐living animals because it is difficult to quantify activity in the field in a consistent, cost‐effective and non‐invasive way.
This article presents a new method to estimate activity level with time‐of‐detection data from camera traps (or more generally any remote sensors), fitting a flexible circular distribution to these data to describe the underlying activity schedule, and calculating overall proportion of time active from this.
Using simulations and a case study for a range of small‐ to medium‐sized mammal species, we find that activity level can reliably be estimated using the new method.
The method depends on the key assumption that all individuals in the sampled population are active at the peak of the daily activity cycle. We provide theoretical and empirical evidence suggesting that this assumption is likely to be met for many species, but may be less likely met in large predators, or in high‐latitude winters. Further research is needed to establish stronger evidence on the validity of this assumption in specific cases; however, the approach has the potential to provide an effective, non‐invasive alternative to existing methods for quantifying population activity levels.
•Many temperate forests harbour high ungulate densities.•Forest diversity, structure and functioning is compromised at high ungulate densities.•Forests respond to browsing in an inverted sigmoidal ...function.•At an ungulate density between 10 and 23 roe deer per km−2 a tipping point is reached, where ungulates have a negative effect on forest regeneration.
Wild ungulates such as red deer, roe deer and wild boar are key drivers of forest ecosystems. Across the northern hemisphere, their range and abundance is increasing, while at the same time forest conversion and habitat fragmentation have led to a large variation in ungulate density and composition among areas. Understanding ungulate density impacts are important in order to prevent shifts towards undesired states, such as from forest to heathland. Here, we assess the effects of ungulate density on forest regeneration, development and functioning. We carried out a systematic literature review of 433 published studies in temperate forests, and used the data to model dose-response curves of the effects of ungulate density on three sets of forest attributes; tree regeneration (abundance, species richness and composition), forest structure (horizontal and vertical), and forest functioning (nutrient cycling in soil, timber and food production). Ungulate density averaged 23.6 km−2 across studies. Ungulates had a negative effect on forest regeneration, structure and functioning in 70% of the evaluated cases. The dose-response curves had a sigmoidal, rather than a unimodal shape. Critical tipping points, where ungulates started to have a negative effect on forest regeneration, were found at an ungulate metabolic weight density of 115 kg km−2 for forest regeneration, 141 kg km−2 for forest structure, and 251 kg km−2 for forest functioning, which is roughly equivalent to 10, 13 and 23 roe deer per km−2. Forest regeneration was most sensitive to immediate browsing and trampling impacts of small seedlings, while forest functioning was least sensitive because of time lags. However, these effects may build up over time. We suggest research priorities for studying ungulate-plant interactions in temperate forests, and make management recommendations how to balance wildlife with a functioning forest.
The Neotropics have many plant species that seem to be adapted for seed dispersal by megafauna that went extinct in the late Pleistocene. Given the crucial importance of seed dispersal for plant ...persistence, it remains a mystery how these plants have survived more than 10,000 y without their mutualist dispersers. Here we present support for the hypothesis that secondary seed dispersal by scatter-hoarding rodents has facilitated the persistence of these large-seeded species. We used miniature radio transmitters to track the dispersal of reputedly megafaunal seeds by Central American agoutis, which scatter-hoard seeds in shallow caches in the soil throughout the forest. We found that seeds were initially cached at mostly short distances and then quickly dug up again. However, rather than eating the recovered seeds, agoutis continued to move and recache the seeds, up to 36 times. Agoutis dispersed an estimated 35% of seeds for >100 m. An estimated 14% of the cached seeds survived to the next year, when a new fruit crop became available to the rodents. Serial video-monitoring of cached seeds revealed that the stepwise dispersal was caused by agoutis repeatedly stealing and recaching each other’s buried seeds. Although previous studies suggest that rodents are poor dispersers, we demonstrate that communities of rodents can in fact provide highly effective long-distance seed dispersal. Our findings suggest that thieving scatter-hoarding rodents could substitute for extinct megafaunal seed dispersers of tropical large-seeded trees.
The ionome—an important expression of the physiological state of organisms—is poorly known for mammals. The focus on particular tissues—such as liver, kidney, and bones—in biomonitoring of ...environmental pollution and potential deficiencies is based on widely held assumptions rather than solid knowledge of full mammalian ionomes. We examined the full ionome of Red deer (
Cervus elaphus
) and Wild boar (
Sus scrofa
), two commonly used mammals for biomonitoring, in a Dutch protected nature reserve (Veluwezoom). We used four individuals per species. We dissected 13 tissues and organs from each individuals (eight in total) of each species and measured 22 elemental concentrations in each. We assessed, for each element, how concentrations varied across tissues within and between individuals. Based on existing literature, we put our findings in the context of their function in the mammalian body. We found that the ionome was highly variable between as well as within the two species. For most elements, tissues containing the highest and lowest concentration differed between individuals. No single tissue accurately represented the accumulation of toxic elements or potential deficiencies in the bodies. Our assessment of the element’s biological roles revealed a serious lack of reference values. Our findings imply that analyses of commonly used tissues in biomonitoring do not necessarily capture bioaccumulation of toxins or potential deficiencies. We recommend establishing a centralized database of mammalian ionomes to derive reference values in future. To our knowledge, our study is one of the most complete assessments of mammalian ionomes to date.
Deletion of the late cornified envelope ( LCE ) genes LCE3B and LCE3C has recently been identified as a risk factor for psoriasis. Expression of 16 LCE genes of LCE groups 1, 2, 3, 5, and 6 was ...examined in vivo and in vitro . Quantitative PCR demonstrated that moderate to high LCE expression was largely confined to skin and a few oropharyngeal tissues. Genes of the LCE3 group demonstrated increased expression in lesional psoriatic epidermis and were induced after superficial injury of normal skin, whereas expression of members of other LCE groups was down-regulated under these conditions. Immunohistochemistry and immunoelectron microscopy demonstrated that LCE2 protein expression was restricted to the uppermost granular layer and the stratum corneum. Stimulation of in vitro reconstructed skin by several psoriasis-associated cytokines resulted in induction of LCE3 members. The data suggest that LCE proteins of groups 1, 2, 5, and 6 are involved in normal skin barrier function, whereas LCE 3 genes encode proteins involved in barrier repair after injury or inflammation. These findings may provide clues to the mechanistic role of LCE 3 B/C deletion in psoriasis.
Negative density dependence (NDD) of recruitment is pervasive in tropical tree species. We tested the hypotheses that seed dispersal is NDD, due to intraspecific competition for dispersers, and that ...this contributes to NDD of recruitment. We compared dispersal in the palm Attalea butyracea across a wide range of population density on Barro Colorado Island in Panama and assessed its consequences for seed distributions. We found that frugivore visitation, seed removal and dispersal distance all declined with population density of A. butyracea, demonstrating NDD of seed dispersal due to competition for dispersers. Furthermore, as population density increased, the distances of seeds from the nearest adult decreased, conspecific seed crowding increased and seedling recruitment success decreased, all patterns expected under poorer dispersal. Unexpectedly, however, our analyses showed that NDD of dispersal did not contribute substantially to these changes in the quality of the seed distribution; patterns with population density were dominated by effects due solely to increasing adult and seed density.
While cheating can cause the degradation or collapse of mutualisms, mutualisms may theoretically stabilize or strengthen if the cheating is mutual. Here, we present an asymmetric two‐player game ...model to explore the evolutionary dynamics of mutual cheating in a mutualistic interaction. We found that the interaction evolved toward mutual cheating if cheating can help both partners obtain higher benefits or if counter‐cheating yields more benefits to victims than simply tolerating exploitation by partners. Then, we present empirical evidence for such mutual cheating strengthening a seed dispersal mutualism in which rodents disperse seeds by scatter hoarding, rodents sabotage seed germination by pruning radicles, and seeds escape rodents by resprouting. By tracking >8,000 Pittosporopsis kerrii seeds throughout the dispersal process in a tropical forest in southwest China, we found that rodents provided better dispersal to seeds that they pruned, i.e., pruned seeds were dispersed farther and were more likely to establish seedlings than unpruned seeds. Compared with unpruned seeds, pruned seeds retained more of their nutrients, i.e., dry mass of pruned seeds was greater than that of unpruned seeds, and were stored for longer by rodents. These findings indicate that mutual cheating benefited both partners. Payoffs estimated from the field experiments indicated that mutual cheating was indeed favored in rodents and plants P. kerrii, and that neither partner was enslaved by the other under mutual cheating. Rather, the mutualism remained stable because the partners were able to exploit each other, and each partner attempted to gain the maximum benefits from the interaction. Our findings indicate that mutual cheating between two mutualists can enhance and stabilize mutualisms.
Many tree species that depend on scatter-hoarding animals for seed dispersal produce massive crops of large seeds at irregular intervals. Mast seeding and large seed size in these species have been ...explained as adaptations to increase animal dispersal and reduce predation. We studied how seed size and seed abundance simultaneously influenced seed dispersal and predation by scatter-hoarding rodents in the large-seeded rain forest tree Carapa procera (Meliaceae) in French Guiana. We individually tracked the fates of 3000 seeds, using remote video monitoring and thread-marking. Seed size was manipulated by broadly varying intraspecific seed mass, whereas effects of seed abundance were examined by tracking seeds in three seed-rich years and two seed-poor years. The hypotheses, that seed mass and seed abundance both enhance dispersal success and that seed abundance reinforces the effect of seed mass, were supported by the results. Most seeds were removed by the scatter-hoarding rodent red acouchy (Myoprocta acouchy) and subsequently were buried in scattered, single-seeded caches up to distances >100 m. Seeds that were not removed failed to establish seedlings. Seed removal was slower, pre-removal seed predation was greater, and seed dispersal was less far in seed-rich years than in seed-poor years, suggesting poorer dispersal under seed abundance. However, this was more than counter-balanced by a disproportionally greater survival of cached seeds in seed-rich years. The per capita probability of seed survival and seedling establishment was at least 4 1/2 times greater under seed abundance. Large seeds were removed faster, were more likely to be scatter-hoarded, and were dispersed farther away than smaller ones, resulting in a higher probability of seedling establishment for larger seeds. Size discrimination was greater under seed abundance, albeit only during seed removal. Overall, large seeds shed in rich years had the highest probability of seedling establishment. Hence, both larger seed size and greater seed abundance stimulate rodents to act more as dispersers and less as predators of seeds. We conclude that scatter-hoarding rodents can select for both large seed crops and large seeds, which may reinforce mast seeding.
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