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Ewing's sarcoma is a recalcitrant tumor greatly in need of more effective therapy. The aim of this study was to determine the efficacy of eribulin on a doxorubicin (DOX)‐resistant Ewing's sarcoma patient derived orthotopic xenograft (PDOX) model. The Ewing's sarcoma PDOX model was previously established in the right chest wall of nude mice from tumor resected form the patient's right chest wall. In the previous study, the Ewing's sarcoma PDOX was resistant to doxorubicin (DOX) and sensitive to palbociclib and linsitinib. In the present study, the PDOX models were randomized into three groups when the tumor volume reached 60 mm3: G1, untreated control (n = 6); G2, DOX treated (n = 6), intraperitoneal (i.p.) injection, weekly, for 2 weeks); G3, Eribulin treated (n = 6, intravenous (i.v.) injection, weekly for 2 weeks). All mice were sacrificed on day 15. Changes in body weight and tumor volume were assessed two times per week. Tumor weight was measured after sacrifice. DOX did not suppress tumor growth compared to the control group (P = 0.589), consistent with the previous results in the patient and PDOX. Eribulin regressed tumor size significantly compared to G1 and G2 (P = 0.006, P = 0.017) respectively. No significant difference was observed in body weight among any group. Our results demonstrate that eribulin is a promising novel therapeutic agent for Ewing's sarcoma.  相似文献   

3.
Zebras, as prey species, attend to the behavior of nearby conspecifics and heterospecifics when making decisions to flee from predators. Plains zebras (Equus quagga) and Grevy's zebras (E. grevyi) frequently form mixed‐species groups in zones where their ranges overlap in Kenya. Although anecdotal observations suggest that Plains zebras are more flighty around humans than Grevy's zebras are, this has not been empirically confirmed, and relatively little is known about how they may influence each other's flight behavior. We addressed these questions by examining the flight initiation distances (FIDs) of Plains and Grevy's zebras in single‐species and mixed‐species groups from an approaching human. One target individual per group was approached steadily on foot, with start distance, alert distance, and FID recorded from this target. Using start distance and alert distance separately as covariates, 22 Plains zebras in single‐species groups exhibited a significantly longer mean FID than 15 Grevy's zebras in single‐species groups. The FIDs of 7 Plains zebras and 5 Grevy's zebras tested in mixed‐species groups were virtually equivalent and intermediate to those of Plains and Grevy's zebras in single‐species groups, suggesting a bidirectional moderating influence of heterospecifics on risk assessment. This effect was most pronounced for Plains zebras in mixed‐species groups that exhibited an FID that was significantly shorter than that of Plains zebras in single‐species groups. Our findings underscore the importance of recognizing that related equids may be differently impacted by anthropogenic stress.  相似文献   

4.
Dabry's sturgeon (Acipenser dabryanus) represents an ancient Actinopterygian lineage that are termed “living fossils”. Many diseases have been found in Dabry's sturgeon. In the present study, genes encoding interleukin (IL)‐16 and IL‐17D in Dabry's sturgeon were identified by RNA‐sequencing. Phylogenetic tree analysis suggested that they clustered together with the corresponding pro‐IL‐16 proteins and IL‐17D proteins from other fish. Sequence analysis revealed that IL‐17D protein was more conserved than pro‐IL‐16. Dabry's sturgeon pro‐IL‐16 contains four putative PDZ domains and do not include signal peptides, while IL‐17D only possesses signal peptides (1–25 aa). The expression patterns of IL‐16 and IL‐17D genes were investigated in Dabry's sturgeon to reveal their functions in disease. The expression level of IL‐16 showed no significant changes in embryos; however, the high expression level of IL‐17D at 0–14 hpf (hours post fertilization) implied the existence of maternal expression in the oocyte and an association with embryonic development. Tissue distribution analysis revealed that IL‐16 and IL‐17D proteins have potential functions in immune and non‐immune tissue compartments. IL‐16 and IL‐17D had different fold changes in primary spleen leukocytes after polyinosinic:polycytidylic acid (poly I:C) and lipopolysaccharide (LPS) administration, which suggested that IL‐16 has a stronger antiviral capability compared with its antibacterial response, and IL‐17D has a stronger antibacterial capability compared with its antiviral response. IL‐16 showed an earlier response to virus compared with IL‐17D, and IL‐17D showed earlier and shorter response to bacteria compared with IL‐16. Our findings suggested the roles of IL‐16 and IL‐17D in Dabry's sturgeon, and provided the theoretical basis for the prevention and control of diseases of Dabry's sturgeon.  相似文献   

5.
There is growing interest in resolving the curious disconnect between the fields of kin selection and sexual selection. Rankin's (2011, J. Evol. Biol. 24 , 71–81) theoretical study of the impact of kin selection on the evolution of sexual conflict in viscous populations has been particularly valuable in stimulating empirical research in this area. An important goal of that study was to understand the impact of sex‐specific rates of dispersal upon the coevolution of male‐harm and female‐resistance behaviours. But the fitness functions derived in Rankin's study do not flow from his model's assumptions and, in particular, are not consistent with sex‐biased dispersal. Here, we develop new fitness functions that do logically flow from the model's assumptions, to determine the impact of sex‐specific patterns of dispersal on the evolution of sexual conflict. Although Rankin's study suggested that increasing male dispersal always promotes the evolution of male harm and that increasing female dispersal always inhibits the evolution of male harm, we find that the opposite can also be true, depending upon parameter values.  相似文献   

6.
We review the ways in which two of Charles Darwin's lesser known works, The Movement and Habit of Twining Plants and The Power of Movement in Plants, stimulated 20th and 21st century research findings and philosophies. The legacy of Darwin's work permeates research on plant movement. For example, Darwin's demonstration that coleoptiles and roots fail to bend in response to light or gravity if their tips are removed helped researchers work toward the discovery of auxin and other plant hormones. Darwin's methodical observations on vine twining directions and circumnutation foreshadowed the recent discovery that 92% of vines twine in right‐handed helices, regardless of their location on the planet. Finally, Darwin's observation of the similarity between plant responses to stimuli and the responses of lower animals foreshadowed the current debate over whether plants have ‘behaviour’. Thus, even Darwin's lesser‐known works continue to influence research in the present day. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 111–118.  相似文献   

7.
In neurons, increased protein–protein interactions between neuronal nitric oxide synthase (nNOS) and its carboxy‐terminal PDZ ligand (CAPON) contribute to excitotoxicity and abnormal dendritic spine development, both of which are involved in the development of Alzheimer's disease. In models of Alzheimer's disease, increased nNOS–CAPON interaction was detected after treatment with amyloid‐β in vitro, and a similar change was found in the hippocampus of APP/PS1 mice (a transgenic mouse model of Alzheimer's disease), compared with age‐matched background mice in vivo. After blocking the nNOS–CAPON interaction, memory was rescued in 4‐month‐old APP/PS1 mice, and dendritic impairments were ameliorated both in vivo and in vitro. Furthermore, we demonstrated that S‐nitrosylation of Dexras1 and inhibition of the ERK–CREB–BDNF pathway might be downstream of the nNOS–CAPON interaction.  相似文献   

8.
I have identified and illustrated a spherical “dimple” or “depression” on the Taung endocast as indicating the most likely position of the medial end of the lunate sulcus but have not drawn an actual lunate sulcus on Taung because one is not visible. In a recent paper, R.L. Holloway (Am. J. Phys. Anthropol. 77:27–33, 1988) drew a lunate sulcus on his copy of the Taung endocast, incorrectly attributed this sulcus to me, and used it to obtain a ratio of 0.254 to describe “Falk's” position of the lunate sulcus. My published ratio of 0.242 for Taung (Falk: Am. J. Phys. Anthropol. 67:313–315, 1985a) was not considered, although the focus of Holloway's paper was my assessment of the position of the lunate sulcus. Holloway also excluded published ratios for a chimpanzee in my collection from his statistical analysis but, even so, my published ratio for Taung is still only 1.5 standard deviations from his chimpanzee mean. If my chimpanzee brain is included in the sample, the ratio for Taung is 1.2 standard deviations from the mean. Furthermore, one of Holloway's own chimpanzees (B60–7) has a ratio of 0.241, just 0.001 below my ratio for Taung. There is no sulcus where Holloway has drawn one on Taung, his “F(LS)” is not mine, his 2 mm error is not mine, and the correct ratio for my measurement of Tuang is the one that I published, not the one that Holloway attributes to me. Assessment of Holloway's chimpanzee data supports my claim that the dimple on the Taung endocast is within the chimpanzee range for the medial end of the lunate sulcus.  相似文献   

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In 1936, Erwin Bünning suggested that photoperiodic time measurement was a function of the circadian system. Colin Pittendrigh became an ardent supporter of Bünning's hypothesis, drawing parallels between photoperiodism and his own group's investigations of adult eclosion rhythmicity in the fruit fly Drosophila pseudoobscura. They developed several more modern versions of Bünning's general hypothesis based on the entrainment of circadian oscillations to the light cycle, including ‘external coincidence’, which is a derivation of Bünning's original model, and ‘internal coincidence’, which relied upon seasonal changes in the mutual phase relationship of oscillators within a multi‐oscillator circadian system. This review considers the experimental evidence for the central role of the circadian system in photoperiodic timing and, in some species, for both external and internal coincidence. Pittendrigh, however, pursued the idea of internal coincidence further with his analysis of the pacemaker–slave organization of eclosion rhythmicity in D. pseudoobscura and proposed a similar theoretical model for photoperiodism comprising a group of slave oscillators driven by a light‐sensitive pacemaker. In this model, the phase relationships of the slaves to the pacemaker were affected by (i) the relative periods of the pacemaker and slave(s); (ii) the strength(s) of the coupling between the two; and (iii) the dampening coefficients of the various slaves. Manipulation of these variables showed that the slaves adopted different internal phase relationships (both to each other and to the pacemaker) under the influence of changes in daily photophase, the period of the Zeitgeber and phase shifts of the entraining light cycle.  相似文献   

11.
In the polymerizations of alanine, γ-ethyl glutamate, and leucine N-carboxyanhydrides (NCA's) initiated by tertiary amines and some secondary amines such as N-methyl-L -alanine dialkylamide, a stereoselectivity was observed: the polymerization rates of L - and D -NCA's were identical to each other and larger than that of DL -NCA. However, this selectivity was not observed in the polymerizations of valine and isoleucine NCA's initiated by N-methyl-L -alanine dialkylamide. The stereoselective polymerizations of valine and isoleucine NCA's were induced only with tetriary amines such as tri-n-butylamine. N-Methyl-L -alanine di-alkylamide has been shown to initiate the polymerization of usual α-amino acid NCA according to the activated-NCA mechanism, but it initiated the polymerizations of valine and isoleucine NCA's according to the primary amine-type mechanism. This is because in the latter NCA's the N–H group is masked by the adjacent Cβ-branched alkyl substituent against the approach of the secondary amine. Poly(DL -alanine)s produced in the stereoselective polymerization had higher viscosities and were more stereoblock-like than those produced without the stereoselectivity. These experimental results indicate that the stereoselective polymerization is possible only when the polymerization proceeds through the activated-NCA mechanism.  相似文献   

12.
Antagonistic host–parasite interactions are rarely considered from an ecological perspective of the parasite. We used a blood‐feeding ectoparasite of boreal cervids, the deer ked (Lipoptena cervi L., Hippoboscidae), to study host‐dependent variation in a parasite's ability to cope with an abiotic environment during the free‐living stage(s) in two allopatric Fennoscandian populations. We found that a strongly host‐specific deer ked population in eastern Fennoscandia, exploiting only moose (Alces alces), produced the largest offspring that were the most cold‐tolerant and emerged the earliest as adults, when compared with the western Fennoscandian population that exploited two hosts efficiently. Within the western population, however, offspring produced on roe deer (Capreolus capreolus) were significantly larger, more cold‐tolerant, and had higher survival than those produced on moose in the same area. We discuss potential causes for both host‐specific and geographical differences in off‐host performance: (1) maternal host directly affects the offspring survival prospects; (2) divergent co‐evolution with local main host(s) has shaped the parasite's life history; and/or (3) off‐host performance is shaped by adaptation to the local abiotic environment. In conclusion, this study increases our understanding of the evolution of host–parasite interactions by demonstrating how geographical differences in host exploitation may result in differences in survival prospects outside the host.  相似文献   

13.
Photoacoustic ophthalmoscopy (PAOM) is capable of noninvasively imaging anatomic and functional information of the retina in living rodents. However, the strong ocular aberration in rodent eyes and limited ultrasonic detection sensitivity affect PAOM's spatial resolution and signal‐to‐noise ratio (SNR) in in vivo eyes. In this work, we report a computational approach to combine blind deconvolution (BD) algorithm with a regularizing constraint based on total variation (BDTV) for PAOM imaging restoration. We tested the algorithm in retinal and choroidal microvascular images in albino rat eyes. The algorithm improved PAOM's lateral resolution by around 2‐fold. Moreover, it enabled the improvement in imaging SNR for both major vessels and capillaries, and realized the well‐preserved blood vessels' edges simultaneously, which surpasses conventional Richardson‐Lucy BD algorithm. The reported results indicate that the BDTV algorithm potentially facilitate PAOM in extracting retinal pathophysiological information by enhancing in vivo imaging quality without physically modifying PAOM's optical configuration.   相似文献   

14.
A seed predatory beetle, Megabruchidius dorsalis (Coleoptera: Chrysomelidae: Bruchinae) native to the Oriental region was first found to utilize a North American Gymnocladus dioica (Fabaceae: Caesalpinioideae) in its introduced area in Central Europe. A maximum of three adult exit holes were found on a single seed. Host‐plants of the bruchine beetle have been reviewed from its native and introduced regions, including a host record of Gleditsia fera from Taiwan. Our review indicated the beetle's strict oligophagy on caesalpinioid Gleditsia species. On the contrary, our finding suggests that the beetle's host‐range extends to the caesalpinioid Umtiza clade. On the plant side, this study provides a counterexample to the enemy release hypothesis that predicts fewer predators/parasites in an organism's range of introduction than in their native range; Gy. dioica is attacked by the seed predator in its introduced region, whereas in its native range it is free from seed predators.  相似文献   

15.
Ropalidia marginata, a primitively eusocial wasp, is different from typical primitively eusocial species in having docile queens who cannot be using dominance to maintain reproductive monopoly and instead appear to use a pheromone from the Dufour's gland to do so. When a docile queen is removed from her colony, one of the workers (potential queen, PQ) becomes highly aggressive, and if the queen is not returned, gradually loses her aggression and becomes the new docile queen within a few days. We hypothesized that the decrease in aggression of the PQ with time since queen removal should be correlated with her change in ovaries and pheromone profile. Because the Dufour's gland hydrocarbon composition in R. marginata can be correlated with fertility, this also gave us an opportunity to test whether PQ is different from workers in her Dufour's gland hydrocarbons. In this study, we therefore trace the road to royalty in R. marginata, that is, the transition of the PQ during queen establishment, in terms of her ovaries, aggression, and Dufour's gland hydrocarbons. Our study focuses on queen establishment, which is important for understanding how reproductive conflict can be manifested and resolved.  相似文献   

16.
Au Pliensbachien, un trend morphologique se developpe chez les Tragophyllocerassimpliquant un mécanisme hétérochronique (paedomorphose par néoténie) pour I'acquisition d'une morphologie suboxycône. Ce changement morphologique majeurest concomitant avecl'ingression de ces formes dans les mers de plateforme euroboréale ob la compétition inter-taxons est forte. Cette option morphofonctionnelle et évolutive, canalisée essentiellement par des contraintes externes étant amorcée, le genre va I'exploiter dans la mesure de ses possibilités (potentialités intrinsèques) en perfectionnant son oxycônie. Au contraire dans les mers téthysiennes, les Juraphyllites ne montrent pas d'évolution pour la morphologie de la coquille; celle-ci reste subplatycône durant tout le Lias moyen et il n'y a pas de changements environnementaux majeurs (milieux tamponnés). En outre la prolifération d'ornementations plus grossières, aussi bien chez les Juraphyllites que chez les Tragopbylloceras, correspond probablement à une meilleure exploitation des biomes d'Europe du NW et de la Téthys à une période bien précise qui est le Carixien moyen. Ce développement d'ornementation similaire chez des taxons partageant un héritage évolutif commun mais séparés paléogéographiquement, évoque le rôle prépondérant des contraintes internes. Ainsi l'évolution des Juraphyllites des Tragophyllocerasau Lias moyen paraît donc ètre un exemple de parallèlisme au sens strict du terme.□Évolution, hétérochronies, Juraphyllitidae, Lias, ontogenèse, Paléogéographie. A morphological trend in the Pliensbachian Tragophyllocerns involves a heterochronic process (paedomorphosis by neoteny) to acquire a suboxycone morphology. This major morphological change is concomitant with the ‘ingression’ of Tragophylloceras in the Euroboreal platform seas, where competition between taxa was strong. This functional-morphological and evolutionary option is mainly canalized by extrinsic constraints. Exploring these possibilities, Tragophylloceras then exploits and improves the oxycone option. By contrast, in the Tethyan seas, Juraphyllites shows no change in shell coiling; it stays subplatycone during all the Pliensbachian. There is no major environmental change. Moreover, the proliferation of coarser ornamentation in Juraphyllitesand Tragophylloceras probably corresponds to a better exploitation of the Euroboreal and Tethyan marine habitats during the Middle Carixian. The development of similar ornamentation in palaeogeographically separate taxa with a common evolutionary origin is mainly canalized by intrinsic constraints. The evolution of Juraphyllites and Tragophylloceras appears to be a good example of parallelism sensu stricto. □ Evolution, heterochrony, Juraphyllitidae, Lios, ontogeny, palaeogeography.  相似文献   

17.
Long‐distance movements are characteristic of most seabirds in the order Procellariiformes. However, little is known about the migration and foraging ranges of many of the smaller species in this order, especially storm‐petrels (Hydrobatidae). We used Global Location Sensors to document the year‐round movements of sympatrically breeding Fork‐tailed Storm‐Petrels (Oceanodroma furcata) and Leach's Storm‐Petrels (O. leucorhoa) from the Gillam Islands located northwest of Vancouver Island, British Columbia, Canada. In 2016, breeding Fork‐tailed (= 5) and Leach's (= 2) storm‐petrels traveled maximum distances of ~1550–1600 km from their colony to a region that has a wide shelf with major canyons creating a highly productive foraging area. After the breeding season, Fork‐tailed Storm‐Petrels (= 2) traveled to similar areas west of the Gillam Islands, a maximum distance of ~3600 km from the breeding colony, and remained in the North Pacific Ocean and north of the Subarctic Boundary for an average of 5.4 mo. Post‐breeding Leach's Storm‐Petrels (= 2) moved south to the Eastern Tropical Pacific, west of central Mexico, Ecuador, and northern Peru, an estimated maximum distance of ~6700 km from their breeding colony, and remained there for an average of 7.2 mo. Carbon (δ13C) and nitrogen (δ15N) stable isotope analyses of feathers revealed niche separation between Fork‐tailed (= 21) and Leach's (= 53) storm‐petrels. The wide range of δ15N values in the feathers of Leach's Storm‐Petrels (= 53) suggests that they foraged at a variety of trophic levels during the non‐breeding season. Our results demonstrate that storm‐petrels have large core foraging areas and occupy vast oceanic areas in the Pacific during their annual cycle. However, given the coarse precision of Global Location Sensors, additional study is needed to identify the specific areas used by each species during both breeding and non‐breeding periods.  相似文献   

18.
The ecology of parasitoids is strongly influenced by their host plant species. Parasitoid fitness can be affected by a variety of plant traits that could promote phenotypic differentiation among populations of parasitoids. Generalist parasitoids are expected to be more affected by plant traits (e.g., plant defensive traits) than specialist parasitoids. Data are presented on phenotypic differences of two braconid parasitoid wasps ovipositing on the same insect host species on two different host plant species. Adult mass, adult longevity, and percent parasitism are compared for the generalist parasitoid Cotesia marginiventris Cresson and the specialist parasitoid Aleiodes nolophanae Ashmead (both Hymenoptera: Braconidae) emerging from green cloverworms, Hypena scabra Fabricius (Lepidoptera: Noctuidae), feeding on two host plant species, alfalfa (Medicago sativa L.) and soybean (Glycine max L. Merr.) (both Fabaceae), at three locations. Specialist wasps that parasitized the green cloverworm on alfalfa had a significantly larger mass than the ones that parasitized the green cloverworm on soybean at the three study sites. Generalist wasps that parasitized green cloverworms on alfalfa had a larger mass than wasps parasitizing green cloverworms on soybean only at one of the study sites (i.e., Prince George's County, MD, USA). Similarly, both specialist and generalist wasps lived longer when parasitizing green cloverworms on alfalfa than when parasitizing them on soybean at only one of the study sites (i.e., Prince George's County). In Prince George's County, percent parasitism on alfalfa by the specialist parasitoid was higher than on soybean for three consecutive years and percent parasitism by the generalist parasitoid was the same on alfalfa and soybean every year. Thus, phenotypic differences among populations associated with different host plant species vary geographically (i.e., parasitoid phenotype associated with different host plant species differ at some sites while it is the same at other sites). The implications of geographic variation for biological control are discussed.  相似文献   

19.
To improve the assessment of magnetic field exposures for occupational health studies, the Multiwave® System III (MW3) was developed to capture personal exposures to the three‐dimensional magnetic field vector B (t) in the 0–3000 Hz band. To process hundreds of full‐shift MW3 measurements from epidemiologic studies, new computer programs were developed to calculate the magnetic field's physical properties and its interaction with biological systems through various mechanisms (magnetic induction, radical pair interactions, ion resonance, etc.). For automated calculations in the frequency domain, the software uses new algorithms that remove artifacts in the magnetic field's Fourier transform due to electronic noise and the person's motion through perturbations in the geomagnetic field from steel objects. These algorithms correctly removed the Fourier transform artifacts in 92% of samples and have improved the accuracy of frequency‐dependent metrics by as much as 3300%. The output of the MwBatch software is a matrix of 41 exposure metrics calculated for each 2/15 s sample combined with 8 summary metrics for the person's full‐period exposure, giving 294 summary‐exposure metrics for each person monitored. In addition, the MwVisualizer software graphically explores the magnetic field's vector trace, its component waveforms, and the metrics over time. The output was validated against spreadsheet calculations with pilot data. This software successfully analyzed full‐shift MW3 monitoring with 507 electric utility workers, comprising over 1 million vector waveforms. The software's output can be used to test hypotheses about magnetic field biology and disease with biophysical models and also assess compliance with exposure limits. Bioelectromagnetics 31:391–405, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   

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