1. Spatial resource subsidies can alter bottom-up and top-down forces of community regulation across ecosystem boundaries. Most subsidies are temporally variable, and recent theory has suggested that ...consumer-resource dynamics can be stabilized if the peak timing of a subsidy is desynchronized with that of prey productivity in the recipient ecosystem. However, magnitude of consumer responses per se could depend on the subsidy timing, which may be a critical component for community dynamics and ecosystem processes. 2. The aim of this study was to test (i) whether a recipient consumer (cutthroat trout) responds differently to a resource subsidy occurring early in its growing season than to a subsidy occurring late in the season and, if this is the case, (ii) whether the timing-dependent consumer response has cascading effects on communities and ecosystem functions in streams. 3. To test those hypotheses, we conducted a large-scale field experiment, in which we directly manipulated the timing of augmentation of the terrestrial invertebrates that enter stream (i.e. peak timing of June—August vs. August—October), keeping constant the total amounts of the invertebrates entered. 4. We found large increases in the individual growth rate and population biomass of the cutthroat trout, in response to the early resource pulse, but not to the late pulse. This timingdependent consumer response cascaded down to reduce benthic invertebrates and leaf breakdown rate, and increased water nutrient concentrations. Furthermore, the early resource pulse resulted in higher maturity rate of the cutthroat trout in the following spring, demonstrating the importance of the subsidy timing on long-term community dynamics via the consumer's numerical response. 5. Our results emphasize the need to acknowledge timing-dependent consumer responses in understanding the effects of subsidies on communities and ecosystem processes. Elucidating the mechanisms by which consumers effectively exploit pulsed subsidies is an important avenue to better understand community dynamics in spatially coupled ecosystems.
Species have phenological variation among local habitats that are located at relatively small spatial scales. However, less studies have tested how this spatial variability in phenology can mediate ...intra-/inter-specific interactions. When predators track phenological variation of prey among local habitats, survival of prey within a local habitat strongly influenced by phenological synchrony with their conspecifics in adjacent habitats. Theory predicts that phenological synchrony among local habitats increases prey survival in local habitat within spatially structured environments because the predators have to make a habitat choice for foraging. Consequently, total survival of prey at regional scale should be higher. By using a spatially explicit field experiment, we tested above hypothesis using a prey–predator interaction between tadpole (
Rhacophorus arboreus
) and newt (
Cynops pyrrhogaster
). We established enclosures (≈regional scale) consisting of two tanks (≈local habitat scale) with different degree of prey phenological synchrony. We found that phenological synchrony of prey between tanks within each enclosure decreased the mean residence time of the predator in each tank, which resulted in higher survival of prey at a local habitat scale, supporting the theoretical prediction. Furthermore, individual-level variation in predator residence time explained the between-tank variation in prey survival in enclosures with phenological synchrony, implying that movement patterns of the predator can mediate variation in local population dynamics of their prey. However, total survival at each enclosure was not higher under phenological synchrony. These results suggest the importance of relative timing of prey phenology, not absolute timing, among local habitats in determining prey–predator interactions.
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease of the neuromuscular junction caused by autoantibodies binding to P/Q-type voltage-gated calcium channels. Breakdown of the ...blood-brain barrier and diffusion of cerebellar granule/Purkinje cell-reactive autoantibodies into the CNS are critical for the pathogenesis of paraneoplastic cerebellar degeneration (PCD) with Lambert-Eaton myasthenic syndrome. We recently found evidence that glucose-regulated protein 78 (GRP78) autoantibodies in the plasma of patients with neuromyelitis optica promote the CNS access of AQP4 autoantibodies. In the present study, we investigated whether the GRP78 autoantibodies in PCD-LEMS IgG boost the brain uptake of cerebellar cell-reactive antibodies across the blood-brain barrier and facilitate cerebellar dysfunction. We first evaluated the effects of purified IgG from PCD-LEMS or PCD patients on the blood-brain barrier function in human brain microvascular endothelial cells using a high content imaging system with nuclear factor κB p65 and intracellular adhesion molecule 1 (ICAM1) immunostaining. Next, we identified GRP78 autoantibodies causing blood-brain barrier permeability in PCD-LEMS IgG by co-immunoprecipitation and the living cell-based antibody binding assays. Exposure of brain microvascular endothelial cells to IgG from PCD-LEMS patients induced nuclear factor κB p65 nuclear translocation, ICAM1 upregulation, reduced claudin-5 expression, increased permeability and increased autocrine IL-1β and IL-8 secretion; the IgG from patients with Lambert-Eaton myasthenic syndrome did not have these effects. We detected GRP78 autoantibodies in the IgG of LEMS-PCD (83.3%, n = 18), but observed fewer in patients with LEMS (6.6%, n = 15) and none were observed in the control subjects (n = 8). The depletion of GRP78 autoantibodies reduced the biological effect of LEMS-PCD IgG on brain microvascular endothelial cells. These findings suggest that GRP78 autoantibodies play a role beyond neuromyelitis optica and that they have direct implications in the phenotypic differences between PCD-LEMS and LEMS.
In a recent article, Freeman (2012) proposes a new approach to the calculation of the Marxian average rate of profit (ARP), namely that marketable financial securities, as well as fixed assets, ...should be included in the denominator of the ARP to ensure that the latter reflects the dramatic increase in the volume and variety of financial instruments in recent decades. By including such securities in the denominator, he also tries to demonstrate that 'there is a consistent long-run fall in the UK and US rate of profit which, contrary to the figures widely used by Marxists, have both fallen almost monotonically since 1968' (2012: 167).
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
One of the possible benefits of robot-mediated education is the effect of the robot becoming a catalyst between people and facilitating learning. In this study, the authors focused on an asynchronous ...active learning method mediated by robots. Active learning is believed to help students continue learning and develop the ability to think independently. Therefore, the authors improved the UGA (User Generated Agent) system that we have created for long-term active learning in COVID-19 to create an environment where children introduce books to each other
robots. The authors installed the robot in an elementary school and conducted an experiment lasting more than a year. As a result, it was confirmed that the robot could continue to be used without getting bored even over a long period of time. They also analyzed how the children created the contents by analyzing the contents that had a particularly high number of views. In particular, the authors observed changes in children's behavior, such as spontaneous advertising activities, guidance from upperclassmen to lowerclassmen, collaboration with multiple people, and increased interest in technology, even under conditions where the new coronavirus was spreading and children's social interaction was inhibited.
Loss of biodiversity is a serious concern, and amphibians are particularly threatened. Most small salamanders in Japan are endangered. Distributional information is fundamental to the conservation of ...these rare species; however, small salamanders are generally difficult to locate or catch. Environmental DNA analysis is an effective survey method for monitoring such rare species. The conventional polymerase chain reaction (PCR) method, which combines PCR amplification with subsequent electrophoresis, and the real-time PCR method, which uses fluorescent material, are commonly used for this purpose. In this study, a comparison of these two detection methods was conducted using a rare salamander species,
Hynobius boulengeri
, as a model case. We compared three points: (i) detection sensitivity, (ii) influence of environmental factors related to detection, and (iii) time and financial costs of the two methods. To perform this comparison, we developed a real-time PCR detection assay, conducted field surveys, and compared the time and financial costs of conventional and real-time PCR methods. The comparison showed no statistical difference in the detection sensitivity from field samples, and the effects of environmental factors tended to be similar. In addition, the financial cost was lower for the conventional PCR method while the time cost was lower for the real-time PCR method. Therefore, selecting eDNA detection methods based on objectives, time, and financial costs will promote efficient monitoring and contribute to the conservation of rare species.
Graphical Abstract
Animal migration mediates many ecological processes by transferring materials and organisms across ecosystems. Migration period in each species is often limited in relatively short‐term. However, ...interspecific variations in migration phenology may prolong migration period at assemblage‐level. In this study, we tested (a) whether and how much degree the timing and duration of freshwater migration differ among amphidromous fish species; (b) in what extent the species diversity prolongs the assemblage‐level migration period. Diverse amphidromous species migrated up the studied river system (Arida River, Japan), with species‐specific migration timing and duration. The large variation in the peak time of migration was found among species within a genus; that is, more than 2‐month difference among four Rhinogobius species. In addition to the within‐genus variation, there was much higher variation across genera (≈4‐month difference in maximum in Sicyopterus japonicus vs. Rhinogobius nagoyae). Collectively, we observed migrating fish over 10 months from March to December in Arida River. The species diversity positively and nonlinearly increased the assemblage‐level migration period, suggesting the importance of species diversity on prolonging resource transfer from marine to freshwater ecosystems.
Diverse amphidromous fishes migrated up a river ecosystem, with species‐specific migration time and duration. This suggested the importance of species diversity on prolonging resource transfer from marine to freshwater ecosystems.
Microbeam radiotherapy (MRT) is based on a spatial fractionation of synchrotron X-ray microbeams at the microscale level. Although the tissue-sparing effect (TSE) in response to non-uniform radiation ...fields was recognized more than one century ago, the TSE of MRT in the testes and its clinical importance for preventing male fertility remain to be determined. In this study, using the combination of MRT techniques and a unique ex vivo testes organ culture, we show, for the first time, the MRT-mediated TSE for the preservation of spermatogenesis. Furthermore, our high-precision microbeam analysis revealed that the survival and potential migration steps of the non-irradiated germ stem cells in the irradiated testes tissue would be needed for the effective TSE for spermatogenesis. Our findings indicated the distribution of dose irradiated in the testes at the microscale level is of clinical importance for delivering high doses of radiation to the tumor, while still preserving male fertility.
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