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1.
Habitats are characterized by different local environmental conditions that influence both behavior and morphology of species, which can result in habitat-dependent phenotypic differences among animals living in heterogeneous environments. We studied 3 alpine populations of Eurasian red squirrels (Sciurus vulgaris), 1 living in a marginal high-elevation habitat at the edge of the species’ altitudinal distribution, and 2 occurring in higher-quality habitats. Here, we investigated whether squirrels living in the marginal area differed in 2 morphological parameters (body size and body mass) and/or in the expression of 4 personality traits estimated with an open field test and a mirror image stimulation test (activity, exploration, activity-exploration, and social tendency). Furthermore, we tested whether within-individual variance of the traits (behavioral plasticity) was higher in the edge habitat. Male squirrels in the edge habitat were smaller and weighed less than in the other study areas, while among females, size–habitat relationships were less marked. These sex-specific patterns were explained by a strong association between body mass and reproductive success in female squirrels. Squirrels in the marginal habitat were more active, explorative, and had a more social personality than in the other habitats. However, in contrast to our predictions, behavioral plasticity was smaller in the marginal habitat, but only for the trait exploration. Our results suggest that animals choose the habitat that best fits their personality, and that habitat-related differences in selective pressures may shape animals’ morphology.  相似文献   
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Comparison of water status indicators for young peach trees   总被引:12,自引:1,他引:12  
We measured a series of physiological and physical indicators and compared them to xylem sap flow, to identify the most sensitive and reliable plant water status indicator. In the growing season of 1998, 4-year-old peach trees (Prunus persica Batsch cv. 'Suncrest', grafted on 'GF 677' rootstock) were studied under two irrigation treatments, 25 l dayу and no irrigation, and during recovery. Trials were conducted near Pisa (Italy) in a peach orchard situated on a medium clay loam soil and equipped with a drip-irrigation system (four 4 l hу drippers per tree). Measurements of leaf water potential (ƒW), stem water potential (ƒS), and leaf temperature (Tl) were taken over 5 days (from dawn to sunset) and analyzed in conjunction with climatic data, sap flow (SF), trunk diameter fluctuation (TDF) and soil water content (SWC). Physiological indicators showed substantial differences in sensitivity. The first indication of changes in water status was the decrease of stem radial growth. TDF and SF revealed significant differences between the two irrigation treatments even in the absence of differences in pre-dawn leaf water potential (pdƒW), up until now widely accepted as the benchmark of water status indicators. Irrigated trees showed a typical trend in SF rate during the day, while in non-irrigated plants the maximum peak of transpiration was anticipated. Measurements of water potential showed ƒS to be a better indicator of tree water status than ƒW. Tl was found to have poor sensitivity. In conclusion, we found the sensitivity of the indicators from the most to the least was: TDF >SF rate >SF cumulated = pdƒWS>mdƒW>Tl.  相似文献   
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Coumarin occurs in many plants used as flavoring and is known to possess hepatotoxic effects. Despite in the EFSA ‘Compendium of botanicals containing toxic substances’ coumarin is reported to be present in Melittis melissophyllum (bastard balm), a plant traditionally used as beverage in Italy and Serbia, to the best of our knowledge quantitative data has never been reported. Thus, the amount of coumarin in bastard balm leaves and its variation during the annual phenological cycle were determined. The subsp. melissophyllum resulted to contain high levels of coumarin (14,392 mg/kg), mainly in the early stages of the plant cycle, suggesting prudence in its use as beverage. Furthermore, coumarin was found to be useful as marker compound to differentiate the bastard balm subspecies occurring in Italy, since the subsp. albida contained a much lower content of this molecule (19–34 mg/kg).  相似文献   
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Apoptosis is the cellular mechanism of ovarian follicular atresia. The major downstream effector of this phenomenon in many tissues is caspase-3 but little is known about its role in pig ovarian apoptosis. In the present study, we detected the localization of caspase-3 in parallel with nuclear fragmentation (TUNEL) on healthy and early atretic antral follicles. In healthy antral follicles caspase-3 and TUNEL positivity were occasionally recorded within theca layer. The incidence of DNA fragmentation, as indicated also by the biochemical detection, increased mainly in the granulosa layer of early atretic follicles. Quantitative analysis revealed, besides, that atresia was accompanied by a higher incidence of caspase-3 (57.20 +/- 20.05 versus 3.64 +/- 0.61 positive cells in atretic versus healthy follicles, respectively; P < 0.05), of TUNEL positivity (20.13 +/- 9.33 versus 0.42 +/- 0.12; P < 0.05) and simultaneous immunostaining for caspase-3 and TUNEL (15.02 +/- 6.95 versus 0.31 +/- 0.05; P < 0.05) in the granulosa layer. In detached granulosa cells isolated from the follicular fluid of early atretic follicles a further significantly increase was recorded in the percentage of TUNEL positivity and in the incidence of cells that showed colocalization of caspase-3 activity and DNA fragmentation. Granulosa cells of early atretic follicles exhibited a higher positivity for caspase-3 localized in the cytoplasm and occasionally in the nucleus area of granulosa cells. These results indicate that capsase-3 was involved and precociously activated during the process of atresia. Finally, the progressively higher incidence of TUNEL positivity and of double immunostaining in atretic cells collected within the follicular fluid seems to indicate that proteases activity leads only tardily in a detectable DNA fragmentation.  相似文献   
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Treatment options for dogs with metastatic (stage III) splenic hemangiosarcoma are limited. A doxorubicin‐based chemotherapy regimen is commonly administered; however, there are no published data to support this practice. The aim of this study was to investigate the impact of maximum‐tolerated‐dose chemotherapy (MTD), metronomic chemotherapy (MC) and no adjuvant treatment on outcome in dogs with stage III splenic hemangiosarcoma undergoing splenectomy. Medical records of dogs with stage III splenic hemangiosarcoma that underwent splenectomy followed by MTD chemotherapy, MC or no adjuvant treatment were retrieved. Time to progression (TTP), survival time (ST) and toxicity were evaluated. One hundred three dogs were identified: 23 received adjuvant MTD, 38 MC and 42 were not medically treated. Overall median TTP and ST were 50 (95% confidence interval [CI], 39‐61) and 55 days (95% CI, 43‐66), respectively. Dogs treated with adjuvant MTD had a significantly longer TTP and ST compared with dogs receiving MC (median TTP, 134 vs 52 days, P = .025; median ST, 140 vs 58 days, P = .023, respectively). Dogs treated by splenectomy only had the shortest median TTP (28 days) and ST (40 days). However, treatment‐related adverse events (AEs) were significantly more frequent in the MTD group (P = .017). The outcome for dogs with metastatic splenic hemangiosarcoma is poor. While MTD showed greater efficacy compared to MC, toxicity was higher in this group. Treatment‐related AEs need to be carefully balanced against this modest survival prolongation when offering adjuvant MTD to dogs with advanced stage hemangiosarcoma.  相似文献   
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This study aimed to set up a method for the long‐term management of Adriatic sturgeon, through the analysis of sex steroids and the genetic profiling of individuals in order to maximize the already reduced genetic variability of this species. Ten A. naccarii adults (nine of captive origin, one captured in the Ticino river and then moved into captivity) and eight subadults located in a semi‐natural land‐locked pond in Abbiategrasso (Milan, Italy) were analysed. Plasma testosterone differed significantly in the eight analysed subadults allowing their differentiation into two groups: the first group with an average testosterone concentration of 5.42 ± 1.31 ng/ml (probably female) and the second group with an average of 423.14 ± 75.97 ng/ml (probably male), as subsequently confirmed by artificial stripping. The plasma testosterone level was also significantly different between adult males and females (371.37 ± 43.58 vs. 95.34 ± 51.10 ng/ml), while the E2 levels showed no significant differences. Animals were genotyped on the basis of 10 microsatellite loci and their parental relationships were defined: four adults, two females and two males, generated the eight subadults. On the basis of pedigree analyses and genetic distances, 15 unrelated couples were identified for the future breeding seasons. Finally, the adult female captured in the Ticino River showed an interesting genetic profile, widely different from all of the other 17 specimens analysed, and represents a valuable source of genetic diversity.  相似文献   
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