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1.
During the first decades of the 20th century, many anthropologists who had previously adhered to a linear view of human evolution, from an ape via Pithecanthropus erectus(today Homo erectus) and Neanderthal to modern humans, began to change their outlook. A shift towards a branching model of human evolution began to take hold. Among the scientific factors motivating this trend was the insight that mammalian evolution in general was best represented by a branching tree, rather than by a straight line, and that several new fossil hominids were discovered that differed significantly in their morphology but seemed to date from about the same period. The ideological and practical implications of imperialism and WWI have also been identified as formative of the new evolutionary scenarios in which racial conflict played a crucial role. The paper will illustrate this general shift in anthropological theory for one particular scientist, William Sollas (1849–1936). Sollas achieved a synthesis of human morphological and cultural evolution in what I will refer to as an imperialist model. In this theoretical framework, migration, conflict, and replacement became the main mechanisms for progress spurred by ‘ ȁ8nature’s tyrant,’ natural selection.  相似文献   

2.
In a military-sponsored research project begun during the Second World War, inmates of the Stateville Penitentiary in Illinois were infected with malaria and treated with experimental drugs that sometimes had vicious side effects. They were made into reservoirs for the disease and they provided a food supply for the mosquito cultures. They acted as secretaries and technicians, recording data on one another, administering malarious mosquito bites and experimental drugs to one another, and helping decide who was admitted to the project and who became eligible for early parole as a result of his participation. Thus, the prisoners were not simply research subjects; they were deeply constitutive of the research project. Because a prisoner’s time on the project was counted as part of his sentence, and because serving on the project could shorten one’s sentence, the project must be seen as simultaneously serving the functions of research and punishment. Michel Foucault wrote about such ‘mixed mechanisms’ in his Discipline and punish. His shining example of such a ‘transparent’ and subtle style of punishment was the panopticon, Jeremy Bentham’s architectural invention of prison cellblocks arrayed around a central guard tower. Stateville prison was designed on Bentham’s model; Foucault featured it in his own discussion. This paper, then, explores the power relations in this highly idiosyncratic experimental system, in which the various roles of model organism, reagent, and technician are all occupied by sentient beings who move among them fluidly. This, I argue, created an environment in the Stateville hospital wing more panoptic than that in the cellblocks. Research and punishment were completely interpenetrating, and mutually reinforcing.  相似文献   

3.
BackgroundShort stature, defined as height for age more than 2 standard deviations (SDs) below the population median, is an important indicator of child health. Short stature (often termed stunting) has been widely researched in low- and middle-income countries (LMICs), but less is known about the extent and burden in high-income settings. We aimed to map the prevalence of short stature in children aged 4–5 years in England between 2006 and 2019.Methods and findingsWe used data from the National Child Measurement Programme (NCMP) for the school years 2006–2007 to 2018–2019. All children attending state-maintained primary schools in England are invited to participate in the NCMP, and heights from a total of 7,062,071 children aged 4–5 years were analysed. We assessed short stature, defined as a height-for-age standard deviation score (SDS) below −2 using the United Kingdom WHO references, by sex, index of multiple deprivation (IMD), ethnicity, and region. Geographic clustering of short stature was analysed using spatial analysis in SaTScan. The prevalence of short stature in England was 1.93% (95% confidence interval (CI) 1.92–1.94). Ethnicity adjusted spatial analyses showed geographic heterogeneity of short stature, with high prevalence clusters more likely in the North and Midlands, leading to 4-fold variation between local authorities (LAs) with highest and lowest prevalence of short stature. Short stature was linearly associated with IMD, with almost 2-fold higher prevalence in the most compared with least deprived decile (2.56% (2.53–2.59) vs. 1.38% (1.35–1.41)). There was ethnic heterogeneity: Short stature prevalence was lowest in Black children (0.64% (0.61–0.67)) and highest in Indian children (2.52% (2.45–2.60)) and children in other ethnic categories (2.57% (2.51–2.64)). Girls were more likely to have short stature than boys (2.09% (2.07–2.10) vs. 1.77% (1.76–1.78), respectively). Short stature prevalence declined over time, from 2.03% (2.01–2.05) in 2006–2010 to 1.82% (1.80–1.84) in 2016–2019. Short stature declined at all levels of area deprivation, with faster declines in more deprived areas, but disparities by IMD quintile were persistent. This study was conducted cross-sectionally at an area level, and, therefore, we cannot make any inferences about the individual causes of short stature.ConclusionsIn this study, we observed a clear social gradient and striking regional variation in short stature across England, including a North–South divide. These findings provide impetus for further investigation into potential socioeconomic influences on height and the factors underlying regional variation.

Joanna Orr and coauthors investigate regional differences in short stature among children in England, between 2006-2019, using a cross-sectional analysis of the National Child Measurement Program data.  相似文献   

4.
Poplar cuttings of a resistant clone, Populus ‘Grandis’, and susceptible clones, Populus nigra ‘Italica’ and Populus ‘Robusta’, were infected with the pathogenic fungus Dothichiza populea alone, or with the pathogen and one of five strains of epiphytes antagonistic towards it (in vitro), isolated from poplar bark. The extent of injury was examined for 28 days after infection by determining the length of necrotic patches and their area as expressed in per cent of the total area of a cutting or the area of necrotic injuries caused by the pathogen alone.All the poplar cuttings of both the resistant and susceptible clones became diseased when infected with the pathogen alone. Surprisingly enough, however, the least affected clone was the susceptible P. ‘Robusta’, in which necrotic injuries covered 28% of the total area, as against 40% and 70% in the resistant P. ‘Grandis’ and the susceptible P. nigra ‘Italica’, respectively.When the cuttings were infected simultaneously with Dothichiza populea and its antagonistic epiphytes, the diseased area in the resistant clone diminished by as much as two-thirds, and in the susceptible P. nigra ‘Italica’, by one-third in comparison with the area affected by the pathogen alone. In turn, in the susceptible P. ‘Robusta’ the introduction of three out of five epiphytes stimulated the growth of the pathogenic fungus producing on average a double increase in the necrotic area. The differences in the response of the pathogen to the presence of epiphytes recorded in the susceptible clones indicate a marked influence of the plant on the nature of interactions between its epiphytic microflora and the pathogen.  相似文献   

5.

Introduction

Although economic development is generally accompanied by improvements in the overall nutritional status of the country’s population the ‘nutritional transition’ often involves a shift to high energy diets and less exercise with negative consequences. This pilot study was done to examine if education of parents operates at the household level to influence dietary choices and the nutritional status of children in a small community of hospital workers.

Material and Methods

3 groups of persons with varying skill and education levels participated. Weighed food logs were used in all households to calculate ‘adult equivalent’ per-capita-consumption. Nutrients were calculated using nutrients calculator software. BMI was used to classify children as underweight, normal weight and overweight.

Results

128 individuals participated from 30 families included 47 children. 10 children (21%) were underweight, 29 (62%) were normal and 8 (17%) were overweight. Energy consumption was highest in families with overweight children 2692 +/-502 compared to 2259 +/-359 in families with normal weight and 2031+/-354 in the family of underweight children. These differences were statistically significant. 42% underweight children belonged to Class 1 at the lowest skill level and there were no overweight children in this group. Most of the overweight children belonged to Class 2. In Class 3 there were no underweight children and the majority was normal weight children.

Conclusion

Underweight children came from the poorer households. Per capita intake of the family as a whole correlated well with BMI in the children. There was increased obesity in middle income families belonging to Class 2—probably in families who move up the scale from deprivation. Nutritional status in children correlated mostly with maternal education status.  相似文献   

6.
This article explores the connections between eugenics, politics and the state, taking the Swiss case as a particular focus. It is argued that Switzerland provides a historical example of what Bauman [Bauman, Z. (1989). Modernity and the Holocaust. Cambridge: Polity Press.] describes as ‘gardening states’: states that are concerned with eliminating the ‘bad weeds’ from the national garden and thereby constructing sharply exclusionary national identities. The Swiss experiments with eugenics (1920s–1960s) can be seen as an example of an ongoing struggle against ‘difference’. Against this backdrop I will examine, first, the ways in which state regulation of reproductive sexuality, and other eugenic measures, became central mechanisms for dealing with cultural and other ‘differences’ in the Swiss nation. Second, I will analyse the gendered nature of such mechanisms, as well as the preoccupation with racial ‘difference’ exemplified by eugenic policies towards ‘Gypsies’. To conclude, I will examine the impact of political institutions and political ideology, in particular, social democracy, on these eugenic gardening efforts.  相似文献   

7.
From the later part of the Devonian through the Permian, calcareous foraminifers became abundant and evolved rapidly. This rapid evolution of taxa forms the basis of a detailed zonation through the Carboniferous and Permian. Comparison of this evolutionary history of foraminifers, their biostratigraphic zonation, and the depositional sequences in which they occur suggests that sea-level events in late Paleozoic depositional history contributed significantly in subdividing a fairly continuous evolutionary record into a succession of about 75 identifiable foraminiferal zones during a 100–125 Myr time span. Although variable in terms of duration and vertical occurrences, the more completely recorded high-stand intervals give brief histories of the foraminiferal evolutionary record and are sandwiched between the poorly recorded or unrecorded low-stand intervals. Many of the individual foraminiferal zones are confined to a single depositional sequence.The late Paleozoic carbonate foraminiferal fossil record, as with the rest of the fossil record, is strongly affected by sediment deposition-nondeposition as a result of major changes in sea level. This incomplete fossil record is the result of repeated depositional breaks because of the way that depositional sequences form. It is not possible to ascribe macromutations, ‘punctuated’ evolution or ‘punctuated gradualism’ as the cause of this evolutionary pattern of the shelf-carbonate fossil record. This pattern is distinctive and we refer to it as ‘sequence evolution’ and ‘sequence extinction’. In the later part of the Middle Permian and in the Late Permian, the fossil record clearly illustrates that a series of faunal losses through ‘sequence extinctions’ progressively exceeded faunal replacements and new species through ‘sequence evolution’, but not a ‘mass extinction’ as is commonly ascribed to the end of the Permian Period. Most Permian faunas became extinct in the interval of 8 to 4 million years before the end of the Late Permian.  相似文献   

8.
Rescued equids are often exposed to rehabilitation and training (or retraining) programmes to improve their physical and psychological well-being as well as to facilitate the re-homing process. Training uses either positive or negative reinforcement learning procedures and it is considered here that, there may be welfare implications associated with using the latter technique as it has the potential to overlay acute stress on animals with a chronic stress life history. The aim of this study, therefore, was to compare these training strategies (negative versus positive reinforcement) on equine behaviour and physiology as the first step in establishing an optimal rehabilitation approach (from a welfare perspective) for equids that have been subjected to chronic stress in the form of long-term neglect/cruelty. Over a 7-week period, 16 ponies (aged 6–18 months) were trained using either positive (‘positive’) (n = 8) or negative reinforcement (‘negative’) (n = 8) techniques to lead in hand, stand to be groomed, traverse an obstacle course and load into a trailer. Heart rate was measured (5 s intervals) on days 1 and 4 of each training week, ‘Pre’- (1 h), ‘During’ (0.5 h) and ‘Post’- (1 h) training session. Ethograms (10.00–20.00 h) outside of the training period were also compiled twice weekly. In addition, weekly arena tests (as a measure of reactivity) were also performed 1 week before and during the 7 weeks of training.Results showed significant differences between the two training schedules for some measures during the latter stages of the trial and suggested that animals trained under a positive reinforcement schedule were more motivated to participate in the training sessions and exhibited more exploratory or ‘trial and error’ type behaviours in novel situations/environments. In this context, the incorporation of positive reinforcement schedules within a rehabilitation programme may be of benefit to the animal from a welfare perspective.  相似文献   

9.
10.
Centaurea ragusina L. (Asteraceae) is an endemic Croatian plant species, which developed xeromorphic characteristics as a consequence of its natural environment – vertical limestone cliffs above the Adriatic sea. Cytogenetic status of C. ragusina long-term culture (94th subculture) and C. ragusina seedlings was analysed and compared after 4 weeks of growth. Cytogenetic stability was investigated in root meristem cells of C. ragusina cultured plants originated from Pen đa (cliffs near Dubrovnik) and seedlings originated from three different localities in south Adriatic (Penđa, Pasjača – cliffs near Dubrovnik and island of Komiža) using mitotic index and mitotic and chromosomal abnormalities as parameters. Mitotic indices of cultured plants and ‘Penđa’ seedlings were similar and showed significant increase compared to mitotic indices of ‘Komiža’ and ‘Pasjača’ seedlings. Although the highest number of mitotic abnormalities was recorded in root meristem cells of cultured plants, it was only a bit higher than in root tips of ‘Pasjača’ and ‘Penđa’ seedlings, while that of ‘Komiža’ was two times lower compared to cultured plants. Pattern of analysed mitotic abnormalities was very similar in root tips of cultured plants and ‘Pasjača’ and ‘Penđa’ seedlings, with exception of ‘Komiža’ seedlings. Presented results suggest that long-term cultivation of C. ragusina has almost no effect on culture ageing considering similar distribution of scored mitotic abnormalities as in ‘Penđa’ and ‘Pasjača’ seedlings.  相似文献   

11.
The subunit molecular mass of α-crystallin, like many small heat-shock proteins (sHsps), is around 20 kDa although the protein exists as a large aggregate of average mass around 800 kDa. Despite this large size, a well-resolved 1H NMR spectrum is observed for α-crystallin which arises from short, polar, highly-flexible and solvent-exposed C-terminal extensions in each of the subunits, αA- and αB-crystallin. These extensions are not involved in interactions with other proteins (e.g. β- and γ-crystallins) under non-chaperone conditions. As determined by NMR studies on mutants of αA-crystallin with alterations in its C-terminal extension, the extensions have an important role in acting as solubilising agents for the relatively-hydrophobic α-crystallin molecule and the high-molecular-weight (HMW) complex that forms during the chaperone action. The related sHsp, Hsp25, also exhibits a flexible C-terminal extension. Under chaperone conditions, and in the HMW complex isolated from old lenses, the C-terminal extension of the αA-crystallin subunit maintains its flexibility whereas the αB-crystallin subunit loses, at least partially, its flexibility, implying that it is involved in interaction with the ‘substrate’ protein. The conformation of ‘substrate’ proteins when they interact with α-crystallin has been probed by 1H NMR spectroscopy and it is concluded that α-crystallin interacts with ‘substrate’ proteins that are in a disordered molten globule state, but only when this state is on its way to large-scale aggregation and precipitation. By monitoring the 1H and 31P NMR spectra of α-crystallin in the presence of increasing concentations of urea, it is proposed that α-crystallin adopts a two-domain structure with the larger C-terminal domain unfolding first in the presence of denaturant. All these data have been combined into a model for the quaternary structure of α-crystallin. The model has two layers each of approximately 40 subunits arranged in an annulus or toroid. A large central cavity is present whose entrance is ringed by the flexible C-terminal extensions. A large hydrophobic region in the aggregate is exposed to solution and is available for interaction with ‘substrate’ proteins during the chaperone action.  相似文献   

12.
Crystalline polysaccharides with 1 → 3−β and 1 → 4−β glycosidic linkages are the most prevalent ones in nature. An interpretation of recent X-ray data on 1 → 3−α glucan shows that it has a ribbon-like crystalline conformation similar to cellulose. Comparison of the crystalline conformation of the four principal homoglucans shows that they fall either in the ‘ribbon-like’ or ‘large amplitude’ helix class. Heteroglucans with a regular sequence of glucosidic linkages show characteristics of the ‘extended conformation’ rather than the ‘coiled conformation’ even when there is 50% of a linkage which in a homoglucan leads to a large amplitude helix. It is concluded that X-ray diffraction analysis fully establishes the hypothesis that the glycosidic linkage type is the determinant of polysaccharide conformation. In this respect, polysaccharides are more like synthetic polymers than proteins or nucleotides; in the latter, it is variation in the substituents which are responsible for the conformational diversity.  相似文献   

13.
This paper presents a comprehensive study of Robert Boyle’s writings on seminal principles or seeds. It examines the role of seeds in Boyle’s account of creation, the generation of plants and animals, spontaneous generation, the generation of minerals and disease. By an examination of all of Boyle’s major extant discussions of seeds it is argued that there were discernible changes in Boyle’s views over time. As the years progressed Boyle became more sceptical about the role of seminal principles in the generation of minerals and he came to reject the spontaneous generation of insects and animals from putrefying matter. It is also argued that Boyle’s notion of a generative or ‘plastick’ principle creates a tension within his mechanical philosophy. He appeals to a plastick power in order to explain those phenomena of generation that are beyond the explanatory resources of the corpuscular hypothesis. However, when pressed to explain the nature of this power he either hints, somewhat paradoxically, that it too can be explained mechanically or admits his nescience.  相似文献   

14.
Abundances and interactions among biological control insects and their effects on target invasive plants were monitored within the flower heads and roots of diffuse knapweed, Centaurea diffusa, and in spotted knapweed, Centaurea stoebe, along the Colorado Front Range. Flower weevils, (Larinus species) and root-feeders (Cyphocleonus achates and Sphenoptera jugoslavica) were released on knapweed that already supported biological control gall flies (Urophora species). At a single monitoring site, seed production by C. diffusa declined from 4400 seeds m−2 in 1997 to zero seeds m−2 on the monitoring sites in 2006, while the flowering stem density of C. diffusa declined from a peak of almost 30 stems m−2 in 2000 to zero stems m−2 in 2006. The average abundance of Urophora and Larinus in flower heads fluctuated independently during the 2001–2006 interval, while the relative abundance of C. achates and S. jugoslavica in roots exhibited a weak inverse relationship that appeared driven by climate effects. The relative abundance of insects on a population of C. stoebe was monitored for five years as Larinus species and C. achates became established on spotted knapweed that already supported Urophora species. Spotted knapweed seed production on our monitoring site declined from 4600 seeds m−2 in 2003 to zero seeds m−2 in 2006. Unlike C. diffusa, substantial numbers of rosettes of C. stoebe remained present. Larinus consumed almost all Urophora encountered in C. diffusa, and consumed about 40% of the Urophora in co-infested flower heads of C. stoebe (ca. 10–15% of the total Urophora population). No negative correlations between the relative densities of flower head and root-feeding insects were observed. The effects of these insects on target plants have produced results consistent with the ‘cumulative stress hypothesis’ for biological control of Centaurea species.  相似文献   

15.
Data on the spermatozoa of Branchiobdellida were taken from the published literature: sperm models of 25 species belonging to 13 different branchiobdellidan genera have been compared with the aim of supplying further evidences for a phylogenetic analysis of the group. The species considered were representative of all traditional branchiobdellidan families, excluding the monotypic Caridinophilidae. Branchiobdellidan spermatozoa are complex cells, thus it was possible to analyse the variation of 20 characters within the group. A parsimony analysis has yielded nine minimal trees, eight of which are very similar to one another. The main conclusions of the phylogenetic analysis are: (a) the monophyly of the taxon Branchiobdellida is confirmed; (b) the most speciose branchiobdellidan genus, Cambarincola is polyphyletic; (c) none of the traditional ‘families’ are supported; (d) the genus Branchiobdella is monophyletic, but the position of one species, B. kobayashi, albeit basal to the whole genus, is not resolved; (e) the other two genera analysed for which more than one species was available, Pterodrilus and Xironogiton, are monophyletic; (f) there seems to be a ‘trend’ in the whole group towards an increase of acrosome length. Our results partly parallel those obtained by Gelder and Siddall (2000) with a combined analysis of molecular and somatic characters, and point to the need for a comprehensive revision of the Branchiobdellida based on a combination of molecular, somatic and spermatological data sets.  相似文献   

16.
Male testosterone (T) levels are thought to be linked with the mating system, degree of parental care, and male–male aggression in reproductive contexts (The ‘challenge hypothesis’; Wingfield et al., 1990). In many species though, T increases associated with mating behavior cannot be separated from those associated with male–male aggression. We tested the challenge hypothesis on aseasonally breeding ursine colobus (Colobus vellerosus), where male–male competition is intense outside of mating contexts. Fecal samples (N = 109) were collected from > 27 subadult and adult males in seven groups during 13-months of research in Ghana in 2004–2005. Fecal T (fT) levels were determined by enzyme immunosorbant assays. Behavioral data was collected using focal-animal and ad libitum sampling. The number of receptive females in each group did not positively correlate with male fT. There was a trend for adult males to have higher fT than subadult males; however there was no effect of rank on fT. The level of male–male aggression experienced was positively correlated with fT and individual males showed higher mean fT during ‘challenge’ than during ‘non-challenge’ periods. The number of male incursions experienced positively correlated with fT whereas the number of between-group encounters did not. Males attempt to gain reproductive opportunities during incursions, thus these results support the ‘challenge hypothesis’ in C. vellerosus. Outside of mating contexts, higher male fT levels are associated with increased aggression. Male parental investment in the form of infant defense was associated with increased fT, rather than the decline expected from other forms of paternal care.  相似文献   

17.
The white-throated Dipper (Cinclus cinclus) is unique among passerine birds by its reliance on diving to achieve energy gain in fast-flowing waters. Consequently, it should have evolved behavioural adaptations allowing responding directly to runoff patterns (one of the assumptions of the Natural Flow Regime Paradigm—NRFP). In this study (October 1998–August 2001), we investigated how behavioural and energy use strategies in Dippers might vary under the natural flow regime of snowmelt-dominated streams in The Pyrénées (France) where natural flow regime is highly seasonal and predictable. We recorded time spent in each of 5 behavioural activities of ringed birds to estimate time–activity budgets and derive time–energy budgets enabling the modelling of daily energy expenditure (DEE). Annual pattern in ‘foraging’ and ‘resting’ matched perfectly the annual pattern of the natural regime flow and there was a subtle relationship between water stage and time spent ‘diving’ the later increasing with rising discharge up to a point where it fell back. Thus, time–activity budgets meet the main prediction of the NRFP. For males and females Dippers, estimates of feeding rates (ratio Eobs/Ereq = observed rate of energy gain / required foraging rate) and energy stress (M = DEE / Basal Metabolic Rate) also partly matched the NFRP. Maximum value for the ratio Eobs/Ereq was registered in May whilst M peaked in spring. These ratios indicated that Pyrenean Dippers could face high energy stress during winter but paradoxically none during high snowmelt spates when food is expected to be difficult to obtain in the channel and when individual birds were observed spending ca 75% of the day ‘resting’. Annual pattern in DEE did not match the NFRP ; two phases were clearly identified, the first between January to June (with oscillating values 240–280 kJ d− 1 ind− 1) and the second between July and December (200–220 kJ d− 1 ind− 1). As total energy expenditure was higher during the most constraining season or life cycle, we suggest that energy management by Dippers in Pyrenean mountain streams may fit the ‘peak total demand’ hypothesis. At this step of the study, it is not possible to tell whether Dippers use an ‘energy-minimisation’ or an ‘energy-maximisation' strategy.  相似文献   

18.
Two alphaproteobacterial Neisser negative ‘Nostocoida limicola’ morphotypes differing slightly in their trichome diameter and filament regularity were dominant populations in the Bendigo, Victoria, Australia activated sludge community removing phosphorus (P). Neither responded to the FISH probes available for any of the other alphaproteobacterial ‘N. limicola’ morphotypes. Instead both fluoresced with the DF988 FISH probe designed originally to target alphaproteobacterial cluster II Defluviicoccus tetrad forming organisms. A 16S rRNA based clone library from this biomass revealed that the alphaproteobacterial clones grouped closely with CandidatusMonilibacter batavus’ and Defluviicoccus clones in a cluster separate from the existing cluster I and II Defluviicoccus. When a FISH probe was designed against these, it only hybridized to the thinner and less abundant ‘N. limicola’ morphotype. Micromanipulation–RT-PCR was used to selectively recover the main ‘N. limicola’ morphotype and a FISH probe designed against the 16S rRNA clones generated from it showed only this filament fluoresced. From FISH based surveys, both ‘N. limicola’ variants occurred frequently in phosphorus removal activated sludge systems in Australia treating domestic waste. The data suggest that they represent two new strains of CandidatusMonilibacter’, which on this evidence are filamentous members of the genus Defluviicoccus, a potential competitor for the polyphosphate accumulating organisms in these communities.  相似文献   

19.
For the design and declaration of conservation areas as well as for planning habitat management it is important to quantitatively know the habitat preferences of the focal species. To take into account the requirements of as many species as possible, it would be of great advantage if one would either (i) find one or several species whose habitat requirements cover those of a large number of other species or if one could (ii) identify a common set of habitat parameters that is important for the occurrence of many species. Ideally such common habitat parameters should be easy to measure. Only then they may be of practical value in applied conservation biology.In this study, we compared the habitat preferences of different insect species (grasshoppers, bush crickets, butterflies, moths) in the same region by applying identical methods. To identify common explanatory variables that predict the occurrence probability of these species, we first tested the transferability of the specific ‘species models’ to other species within the same insect group. We tested how well the incidence of one species can be predicted by the occurrence probability of another species. The ‘best’ models within each group were then tested for transferability between the different groups. Additionally, we tested the predictive power of the predictor variable ‘habitat type’ as an easy and often available measure for conservation practice.Although in the different ‘species models’ different key factors determine habitat suitability, some models were successfully transferred and were able to reasonably predict the distribution of other species. The habitat preferences of the burnet moth Zygaena carniolica were particularly well suited for the prediction of suitable habitats for all other species. In addition, the predictor variable ‘habitat type’ played a dominant role in all models. Models using this aggregated predictor variable may well predict suitable habitat for all species.  相似文献   

20.
Pengmin Li  Lailiang Cheng   《Plant science》2009,177(5):418-426
Pigments, chlorophyll fluorescence, dark respiration, and the antioxidant system in the shaded peel of green ‘Anjou’ pear (Pyrus communis L.) and its bud mutation, red ‘Anjou’, were compared in response to high peel temperature, high light alone or in combination to determine the protective role of anthocyanins under high temperature with or without light. Under high temperature treatment alone, no difference in the maximum quantum yield of PSII (FV/FM) was detected between red ‘Anjou’ and green ‘Anjou’; the superoxide dismutase activity and the glutathione pool were up-regulated in green ‘Anjou’ peel but remained unchanged in red ‘Anjou’ peel. Under high temperature coupled with high light, the FV/FM of green ‘Anjou’ peel was decreased to a lower value than that of red ‘Anjou’, and significant interaction was detected between temperature and light for both cultivars. Furthermore, the difference in FV/FM between red ‘Anjou’ and green ‘Anjou’ under high temperature coupled with high light was significantly larger than that under high light alone, indicating that this larger difference was caused by the interaction between high temperature and high light as no significant difference was detected in FV/FM between the two cultivars under high temperature treatment alone at any sampling point. It is concluded that the elevated anthocyanin level in the shaded peel of red ‘Anjou’ does not alter its thermotolerance in the dark, but makes it more tolerant of high temperature under high light.  相似文献   

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