Temperature is a major factor affecting population abundance and individual performance. Net reproductive rate (R0) and intrinsic rate of increase (r) differ in their response to different ...temperature regimes, and much of the difference is mediated by generation time (Tg). Here, we evaluate the effects of thermal mean and variability on R0, r and Tg, at four population densities in Drosophila melanogaster. The results show that R0, r and Tg present differential responses to thermal variation. Although temperature effects on R0 and Tg are non-linear, r response was negligible. R0 and Tg comprise a generational time scale, while r is at a chronological time scale. Thus, we argue that individuals growing under different thermal environments perform similarly on a chronological scale, but differently on a generational scale.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The maintenance of sexuality is a puzzling phenomenon in evolutionary biology. Many universal hypotheses have been proposed to explain the prevalence of sex despite its costs, but it has been ...hypothesized that sex could be also retained by lineage‐specific mechanisms that would confer some short‐term advantage. Aphids are good models to study the maintenance of sex because they exhibit coexistence of both sexual and asexual populations within the same species and because they invade a large variety of ecosystems. Sex in aphids is thought to be maintained because only sexually produced eggs can persist in cold climates, but whether sex is obligate or facultative depending on climatic conditions remains to be elucidated. In this study, we have inferred the reproductive mode of introduced populations of the pea aphid Acyrthosiphon pisum in Chile along a climatic gradient using phenotypic assays and genetic‐based criteria to test the ecological short‐term advantage of sex in cold environments. Our results showed a latitudinal trend in the reproductive mode of Chilean pea aphid population from obligate parthenogenesis in the north to an intermediate life cycle producing both parthenogenetic and sexual progeny in the southernmost locality, where harsh winters are usual. These findings are congruent with the hypothesis of the ecological short‐term advantage of sex in aphids.
Invasive population of Acyrthosiphon pisum in Chile is structured along a latitudinal transect. The southernmost one, where winters are harsh, is the only one that exhibits genetic and phenotypic features of sexual reproduction.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The most remote isotope from the proton dripline (by 4 atomic mass units) has been observed: K-31. It is unbound with respect to three-proton (3p) emission, and its decays have been detected in ...flight by measuring the trajectories of all decay products using microstrip detectors. The 3p emission processes have been studied by the means of angular correlations of S-28 + 3p and the respective decay vertices. The energies of the previously unknown ground and excited states of K-31 have been determined. This provides its 3p separation energy value S-3p of -4.6(2) MeV. Upper half-life limits of 10 ps of the observed K-31 states have been derived from distributions of the measured decay vertices.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Background:
Talus fractures are one of the most dangerous injuries leading to serious consequences. Quite a lot of treatment methods have been proposed, but the use of the Ilizarov apparatus is ...relatively rare.
Objective:
To justify the use of the Ilizarov apparatus in the talus fracture treatment by studying radiomorphological parameters of the foot bones at different stages of follow-up.
Methods:
We used radiography and multislice computed tomography (MSCT) in 25 patients treated for talus injuries by the Ilizarov apparatus to study radiographic and radiomorphological features of the foot bones at different stages of follow-up. We analyzed normal parameters of the foot bones forming the ankle joint in 15 patients.
Results and discussion:
Dynamics of talus radiomorphology during its fracture or fracture-dislocation are characterized by a gradual increase in the bone density at the union site. The local density of the talus at the fracture site gradually increased and exceeded 500 HU in 6 months. The organotypic adjustment at the union site did not end by this time, given the architecture of the talus and the biomechanics of the foot. We observed a decrease in the total densities of the talus and calcaneus during fixation by the Ilizarov apparatus and their gradual return to normal values after removal of the apparatus.
Conclusions:
Talus fracture treatment by transosseous osteosynthesis using the Ilizarov apparatus makes it possible to get immediate good results, especially using a configuration with hinges allowing for early mobilization of the ankle joint and loading in the early stages of treatment.
Changes in temperature across geographic gradients can occur on a wide temporal range, from fluctuations within hours as a result of day-night to those over many years. These events will drive many ...organisms towards their physiological limits of thermal tolerance. Recently, many reports support a limited scope for adaptive evolutionary responses to high temperatures, meaning a conserved heat tolerance among ectotherms in general. We address this problem and tested the heat and cold tolerance invariant–variant hypotheses in terrestrial isopods. We studied five different populations of Porcellio laevis and three populations of Porcellio scaber, spanning 30° S latitudinal gradient in Chile. The heat tolerance of woodlice was conserved with little variation along latitude and environmental temperatures, but cold tolerance decreases significantly with environmental temperatures and latitudes. Indeed, a significant and negative correlation was observed between cold tolerance and latitude. Also, significant and positive correlations were observed among cold tolerance and environmental temperatures. Conversely, heat tolerance was not significantly correlated with any of the environmental temperatures tested neither with latitude. This macrophysiological pattern indicated that heat and cold-tolerances of species and populations not always change across geographical gradients meaning that thermal tolerance responses to high temperatures may be evolutionary constrained.
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IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, UL, UM, UPCLJ, UPUK
Proton halo effects in the 8B+64Zn reaction at an energy around 1.5 times the Coulomb barrier have been studied at HIE-ISOLDE CERN using, for the first time, the only existing postaccelerated 8B ...beam. This, together with the use of a high granularity and large solid angle detection system, allowed for a careful mapping of the elastic angular distribution, especially in the Coulomb-nuclear interference region. Contrary to what is observed for the one-neutron halo nucleus 11Be on the same target in a similar energy range, the analysis of the elastic scattering angular distribution shows only a modest suppression of the Coulomb-nuclear interference peak, with no remarkable enhancement of the total reaction cross-section. Inclusive angular and energy distributions of 7Be produced in direct reaction processes have also been measured. The comparison of these data with the results of theoretical calculations for the elastic and non-elastic breakup contributions indicate that both processes are important. Overall, the experimental data suggest a 8B collision dynamics at the barrier very different from the one of neutron halo nuclei, showing only modest effects of coupling to continuum. This behaviour can be interpreted as due to the presence of the additional Coulomb interactions halo-core and halo-target together with the presence of the centrifugal barrier felt by the valence proton of 8B.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Prospects of experimental studies of argon and chlorine isotopes located far beyond the proton dripline are studied by using systematics and cluster models. The deviations from the widespread ...systematics observed in Cl-28,Cl-29 and Ar-29,Ar-30 have been theoretically substantiated, and analogous deviations have been predicted for the lighter chlorine and argon isotopes. The limits of nuclear structure existence are predicted for Ar and Cl isotopic chains, with Ar-26 and Cl-25 found to be the lightest sufficiently long-living nuclear systems. By simultaneous measurements of protons and gamma rays following decays of such systems as well as their beta-delayed emission, an interesting synergy effect may be achieved, which is demonstrated by the example of Cl-30 and Ar-31 ground-state studies. Such a synergy effect may be provided by the new EXPERT setup (EXotic Particle Emission and Radioactivity by Tracking) being operated inside the fragment separator and spectrometer facility at GSI, Darmstadt.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We investigated the performance of synthetic high purity monocrystalline diamond radiation detectors fabricated with TiW, Cr/Au and a novel metallization technique utilising diamond-like carbon ...tunnelling junction and Pt/Au as electrical contacts. The investigation was carried out under irradiation with 60 Co gamma-rays, 90 Sr electrons and 241 Am alpha-particles. The experimental results with respect to I - V dark current levels, irradiation photocurrent, signal-to-noise ratio and time response have been compared and discussed. Results show an ohmic behaviour of the DLC/Pt/Au contact, a charge collection efficiency of 100% at an applied electric field of 0.377 V/ mum for all electrical contacts (under 90 Sr electrons irradiation) at a correspondent dark current value of less than a picoAmpere. The single crystal CVD DLC/Pt/Au diamond radiation detector reported here shows spectroscopic energy resolution of 1.1% at an applied voltage of +450 volts (0.9 V/mum) under 5.5 MeV alpha particle irradiation. No dasiamemorypsila or dasiapumpingpsila effect was observed for the DLC/Pt/Au contact at positive bias; the signal was also stable (fluctuations below 0.5%) and reproducible under 60 Co irradiation, with a signal-to-noise ratio > 10000:1 and a linearity in the dose rate response.
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