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1.
Based on a long-term dataset (1999–2010), we investigated how the availability of main prey affects the breeding density and food ecology of the Tengmalm’s owl (Aegolius funereus) in the Czech Republic. In particular, we assessed the role of Microtus voles and Apodemus mice in the diet, based on the main predictions of the optimal diet theory that the diet composition depends on the availability of the main prey. We found that (i) the Tengmalm’s owl exhibited no numerical response to the availability of Microtus voles and Apodemus mice in the field; (ii) the availability of Apodemus mice in the field positively affected their proportion in the diet (26 %), and despite a high proportion of Microtus voles in the owls’ diet (47 %), no relationship was found between their availability in the field and proportion in the diet; (iii) the proportion of Apodemus mice was negatively correlated to the proportion of Microtus voles, Sorex shrews and birds in the diet, but no similar relationship was detected for Microtus voles; (iv) the reproductive output of Tengmalm’s owls was positively correlated to the proportion of Apodemus mice in the diet, as well as to Apodemus mice and Microtus vole availability in the field; and (v) diet diversity and diet overlap were not significantly affected by the abundance of Apodemus mice and Microtus voles. Therefore, the validity of these main optimal diet theory predictions was not confirmed, especially for Microtus vole prey, due to an opportunistic choice between Apodemus mice and Microtus voles. We suggest that the reproductive output of nocturnal raptors in Central Europe may be less dependent on Microtus vole supply than that of their northern counterparts.  相似文献   

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Gordon McOuat 《ZooKeys》2016,(550):57-69
By the late 19th Century, storms plaguing early Victorian systematics and nomenclature seemed to have abated. Vociferous disputes over radical renaming, the world-shaking clash of all-encompassing procrustean systems, struggles over centres of authority, and the issues of language and meaning had now been settled by the institution of a stable imperial museum and its catalogues, a set of rules for the naming of zoological objects, and a new professional class of zoologists. Yet, for all that tranquillity, the disputes simmered below the surface, re-emerging as bitter struggles over synonyms, trinomials, the subspecies category, the looming issues of the philosophy of scientific language, and the aggressive new American style of field biology – all pressed in upon the received practice of naming and classifying organisms and the threat of anarchy. In the midst rose an index. This paper will explore the context of CD Sherborn’s Index Animalium and those looming problems and issues which a laborious and comprehensive “index of nature” was meant to solve.  相似文献   

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This work describes a practical way to optimize the high level of the chef creativity to produce rational approaches to food design. It is particularly focused on the preparation of two dishes: bubbly juice and false skin. For the first dish, three samples were prepared with egg white protein (EWP) and xanthan gum at pH 4.6 and pH 7.0. At pH 4.6 (isoelectric point), there were substantial differences of the interfacial dilational modulus of EWP when xanthan gum was added. At 1 mg/ml xanthan, the system showed a very strong interface (high viscoelasticity) compared to the other samples. Measuring half drainage time revealed which samples were the most stable. The properties discussed were related to stability. For the false skin dish, edible films were made by gelatin extracted from cod skins (A solution) and a mixture of cod skin gelatin and commercial gelatin (AG solution). The results showed that tensile strength (TS) of gelatin films increases almost by 25%, elongation at break (EAB) by 14%, and the Young modulus (E) by almost 100% when increasing protein concentration. To confirm water plasticizer effect, the results were compared to a gelatin film made with 30% glycerol (plasticizer). Water content affects to a great extent the mechanical properties of the films. Finally, images of the dishes are presented in order to have a full view of the purpose and the results obtained. This research has been supported by the Department of Agriculture and Fisheries from the Basque Government. This work was presented at the conference Delivery of Functionality in Complex Food Systems, Amherst, USA, October, 2007.  相似文献   

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Journal of the History of Biology - The article “Diauxic Inhibition: Jacques Monod’s Ignored Work”, written by Pierre Louis Blaiseau and Allyson M. Holmes, was originally...  相似文献   

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Central Europe faces an influx of terrestrial invertebrates from more southerly regions, in particular from the Mediterranean. This process is particularly noticeable among terrestrial gastropods. In the last 30 years, the number of non-native land snail species found outdoors in the Czech Republic increased from 5 to 15 (8% of all species); more than half of these have presumed Mediterranean origin. The trend has accelerated recently; seven new alien species (six Mediterranean) have been recorded since 2000. As the most recent example, we report the finding of a large helicid species from the South-East Mediterranean, Helix lucorum. A well-established overwintering population was found in Prague, over 400 km from the nearest known localities of the species. This trend of newly established snails corresponds with increases in average temperatures as well as the intensity of foreign trade in the past six decades, suggesting a synergistic effect of both climatic conditions and socioeconomic factors.  相似文献   

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The European flora is of global significance but many species are facing an ever increasing range of threats, especially the growing impacts of climate change. While various estimates have been made for the number of threatened plant species in Europe, an up-to-date European plant Red List does not presently exist. Target 8 of the Global Strategy for Plant Conservation (GSPC) calls for 60% of threatened plant species to be conserved in ex situ collections by 2010. In the absence of a European plant Red List, it is difficult to monitor progress at the regional level towards this target. To address this gap Botanic Gardens Conservation International (BGCI) has developed a consolidated list of European threatened species as a step towards a formal Red List. The database consists of national Red List data from 28 European countries and includes records for over 11,000 taxa. National Red List data were supplemented by information on the critically endangered plants of Europe provided by the Museum National d’Histoire Naturelle/European Topic Centre on Biological Diversity and the Conservatoire Botanique National de Brest. A list of regionally threatened species was extracted from the database and screened against BGCI’s database of plants in cultivation in botanic gardens (PlantSearch) and ENSCONET’s (European Native Seed Conservation Network) database of plants conserved in European seed banks. This analysis revealed that 42% of European threatened species are currently included in ex situ conservation programmes in Europe.  相似文献   

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《Plains anthropologist》2013,58(77):183-187
Abstract

Audrey’s Overhang, a small pictograph site in Montana’s Smith River Drainage, is part of a highly abstract rock art style localized in the Rocky Mountain foothills of central Montana. An abstract anthropomorph at Audrey’s Overhang is similar to those at several nearby sites. Site characteristics suggest that the pictographs of this rock art style were painted as part of a vision guest ceremony. Because the rock art of much of the surrounding area is poorly known the external relationships of this central Montana rock art style remain to be demonstrated.  相似文献   

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Capsule: The Western Bonelli’s Warbler Phylloscopus bonelli has a nest success of only 25% in the core of its range in western Europe.

Aims: To investigate the breeding biology of Western Bonelli’s Warbler P. bonelli, focusing on possible altitude effects and potential reproductive problems.

Methods: Three Western Bonelli’s Warbler populations were monitored during the 2012 and 2013 breeding seasons in the massif range of Sierra Nevada, Spain. We determined all the breeding parameters and calculated daily survival and success rates for each reproductive period.

Results: The three studied populations did not differ in any breeding parameters. Altitude showed a positive relationship with clutch size and duration of incubation period, but a negative relationship with nestling tarsus growth and body mass gain. Daily survival rates during incubation and nestling periods were similar to those of common warblers, but the species presented a low breeding success of 25%.

Conclusion: The absence of differences among the three populations suggests that the information provided here could be representative of its distribution in the woodlands of Sierra Nevada. The novel and detailed information reported is crucial not only for expanding our understanding of this species but also to draw attention to the potential risks that it might face in the near future, considering the reduction that this species has suffered in Sierra Nevada during recent decades.  相似文献   


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Media portraying violence is part of daily exposures. The extent to which violent media exposure impacts brain and behavior has been debated. Yet there is not enough experimental data to inform this debate. We hypothesize that reaction to violent media is critically dependent on personality/trait differences between viewers, where those with the propensity for physical assault will respond to the media differently than controls. The source of the variability, we further hypothesize, is reflected in autonomic response and brain functioning that differentiate those with aggression tendencies from others. To test this hypothesis we pre-selected a group of aggressive individuals and non-aggressive controls from the normal healthy population; we documented brain, blood-pressure, and behavioral responses during resting baseline and while the groups were watching media violence and emotional media that did not portray violence. Positron Emission Tomography was used with [18F]fluoro-deoxyglucose (FDG) to image brain metabolic activity, a marker of brain function, during rest and during film viewing while blood-pressure and mood ratings were intermittently collected. Results pointed to robust resting baseline differences between groups. Aggressive individuals had lower relative glucose metabolism in the medial orbitofrontal cortex correlating with poor self-control and greater glucose metabolism in other regions of the default-mode network (DMN) where precuneus correlated with negative emotionality. These brain results were similar while watching the violent media, during which aggressive viewers reported being more Inspired and Determined and less Upset and Nervous, and also showed a progressive decline in systolic blood-pressure compared to controls. Furthermore, the blood-pressure and brain activation in orbitofrontal cortex and precuneus were differentially coupled between the groups. These results demonstrate that individual differences in trait aggression strongly couple with brain, behavioral, and autonomic reactivity to media violence which should factor into debates about the impact of media violence on the public.  相似文献   

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Alzheimer’s disease (AD) is an irreversible and progressive neurodegenerative disorder with no known cure or clear understanding of the mechanisms involved in the disease process. Amyloid plaques, neurofibrillary tangles and neuronal loss, though characteristic of AD, are late stage markers whose impact on the most devastating aspect of AD, namely memory loss and cognitive deficits, are still unclear. Recent studies demonstrate that structural and functional breakdown of synapses may be the underlying factor in AD-linked cognitive decline. One common element that presents with several features of AD is disrupted neuronal calcium signaling. Increased intracellular calcium levels are functionally linked to presenilin mutations, ApoE4 expression, amyloid plaques, tau tangles and synaptic dysfunction. In this review, we discuss the role of AD-linked calcium signaling alterations in neurons and how this may be linked to synaptic dysfunctions at both early and late stages of the disease.  相似文献   

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There are several systemic and intracerebral pathologic conditions, which limit provision and utilization of energy precursor metabolites in neuronal cells. Energy deficits cause excessive depolarization of neuronal cells triggering glutamate-zinc evoked excitotoxic cascade. The intracellular zinc excess hits several intraneuronal targets yielding collapse of energy balance and impairment functional and structural impairments cholinergic neurons. Disturbances in metabolism of acetyl-CoA, which is a direct precursor for energy, acetylcholine, N-acetyl-l-aspartate and acetylated proteins synthesis, play an important role in these pathomechanisms. Disruption of brain homeostasis activates slow accumulation of amyloid-β 1?42 , which extra and intracellular oligomeric deposits disrupt diverse transporting and signaling processes in all membrane structures of the cell. Both neurotoxic signals may combine aggravating detrimental effects on neuronal cell. Different neuroglial and neuronal cell types may display differential susceptibility to similar pathogenic insults depending on specific features of their energy and functional parameters. This review, basing on findings gained from cellular and animal models of Alzheimer’s disease, discusses putative energy/acetyl-CoA dependent mechanism in early and late stages of neurodegeneration.  相似文献   

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In addition to cognitive decline, individuals affected by Alzheimer’s disease (AD) can experience important neuropsychiatric symptoms including sleep disturbances. We characterized the sleep-wake cycle in the TgCRND8 mouse model of AD, which overexpresses a mutant human form of amyloid precursor protein resulting in high levels of β-amyloid and plaque formation by 3 months of age. Polysomnographic recordings in freely-moving mice were conducted to study sleep-wake cycle architecture at 3, 7 and 11 months of age and corresponding levels of β-amyloid in brain regions regulating sleep-wake states were measured. At all ages, TgCRND8 mice showed increased wakefulness and reduced non-rapid eye movement (NREM) sleep during the resting and active phases. Increased wakefulness in TgCRND8 mice was accompanied by a shift in the waking power spectrum towards fast frequency oscillations in the beta (14-20 Hz) and low gamma range (20-50 Hz). Given the phenotype of hyperarousal observed in TgCRND8 mice, the role of noradrenergic transmission in the promotion of arousal, and previous work reporting an early disruption of the noradrenergic system in TgCRND8, we tested the effects of the alpha-1-adrenoreceptor antagonist, prazosin, on sleep-wake patterns in TgCRND8 and non-transgenic (NTg) mice. We found that a lower dose (2 mg/kg) of prazosin increased NREM sleep in NTg but not in TgCRND8 mice, whereas a higher dose (5 mg/kg) increased NREM sleep in both genotypes, suggesting altered sensitivity to noradrenergic blockade in TgCRND8 mice. Collectively our results demonstrate that amyloidosis in TgCRND8 mice is associated with sleep-wake cycle dysfunction, characterized by hyperarousal, validating this model as a tool towards understanding the relationship between β-amyloid overproduction and disrupted sleep-wake patterns in AD.  相似文献   

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Atypical face processing plays a key role in social interaction difficulties encountered by individuals with autism. In the current fMRI study, the Thatcher illusion was used to investigate several aspects of face processing in 20 young adults with high-functioning autism spectrum disorder (ASD) and 20 matched neurotypical controls. “Thatcherized” stimuli were modified at either the eyes or the mouth and participants discriminated between pairs of faces while cued to attend to either of these features in upright and inverted orientation. Behavioral data confirmed sensitivity to the illusion and intact configural processing in ASD. Directing attention towards the eyes vs. the mouth in upright faces in ASD led to (1) improved discrimination accuracy; (2) increased activation in areas involved in social and emotional processing; (3) increased activation in subcortical face-processing areas. Our findings show that when explicitly cued to attend to the eyes, activation of cortical areas involved in face processing, including its social and emotional aspects, can be enhanced in autism. This suggests that impairments in face processing in autism may be caused by a deficit in social attention, and that giving specific cues to attend to the eye-region when performing behavioral therapies aimed at improving social skills may result in a better outcome.  相似文献   

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