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《Comptes Rendus Palevol》2008,7(4):211-216
A new leaf-mimicking katydid (Orthoptera: Tettigoniidae: Pseudophyllinae), Archepseudophylla fossilis gen. et sp. nov. is described based on tegmina from the Early Oligocene of France. Lithymnetes laurenti Théobald, 1937 from the Late Eocene of France is transferred to Archepseudophylla comb. nov. The enigmatic ‘Poekillopteramelanospila Cockerell, 1921 from the Early Oligocene of the Isle of Wight (UK) is transferred to Archepseudophylla comb. nov. The present discoveries in the Palaeogene of the Isle of Wight, Céreste, and Marseilles Basins represent the first fossil records of Pseudophyllinae. In addition, these records support warm and humid forest conditions near the palaeolakes of the Isle of Wight, Camoins-les-Bains, and Céreste.  相似文献   

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In this study I examine the variability in calling activity of Sciarasaga quadrata over both the short (4 d) and long term (life span), and the temporal pattern to host searching by its most significant natural enemy, the ormiine fly Homotrixa alleni. Indeed, few male S. quadrata survive the entire calling season as this acoustically orienting parasitoid fly continually ‘culls’ calling males out of the population. I found that male S. quadrata commence calling over 1 h before sunset, cease around midnight and call, on average, for over 3 h within this period (range 0–11 h 09 min). There was significant concordance and repeatability in calling activity over both the short and long term, enabling me to conclude that relative differences in calling activity among males persist throughout a male's life span. There was a distinct peak to host searching by gravid female flies, with 82 % of all flies collected at acoustic traps between sunset and midnight. A positive association between call duration (time spent calling) and fly attraction was evident from multiple collections of flies at single traps. Counter to expectation, there was no significant decline in average call duration across successive collections of males, indicating that long-call-duration males were not being selectively culled by flies from the calling population. Males at the end of the calling season, when their remaining reproductive potential is low, allocate the majority of their calling time between sunset and midnight despite the high risk of fly attack. The distribution of call durations within the population was not skewed, which if heritable, indicates a lack of history of directional selection acting on call duration. Limited evidence suggests that encounters with females are rare in S. quadrata so that males may be selected, irrespective of natural selection pressure, to call for long periods of time to optimize their chance of attracting mates. The above findings are further discussed in relation to parasitoid foraging and acoustic reproductive strategies.  相似文献   

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The northwestern distributions of several steppe species of Orthoptera extend to the southeastern part of the Czech Republic (Pannonia) and occupy more or less isolated fragments of optimal habitats. Their distributional limits are not conditioned by macroclimate in most cases but reflect landscape development (physical structure, plant community type and microclimate) and the insects’ dispersal abilities. These species prefer permanent grassland, and assessment of land use records indicates that the area occupied by permanent grassland has been greatly reduced by agriculture over the last two centuries. The area occupied by permanent grasslands in Pannonia was highest in the nineteenth century, declined until the second half of the twentieth century, and slightly increased at the beginning of the twenty first century. These changes in the area of permanent grassland generally reflect economic and political processes; in particular, consolidation of land plots and expropriation of private property brought an end to grazing. The distribution of a model Orthoptera specialist, Platycleis vittata, on steppe habitats was surveyed at 48 potentially suitable locations from 2004 to 2010. The survey determined that the area with suitable habitat is currently very limited at all 48 locations. Occurrence was confirmed in just two locations that are 3 km apart. The research suggests that Platycleis vittata in the Czech Republic is on the brink of extinction because of extreme fragmentation of suitable biotopes and degradation of optimal habitats.  相似文献   

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This study deals with the acid phosphatase (AcPase) of the Kurloff body (KB), a large (10 μm diameter) periodic acid-Schiff-positive lysosomal inclusion body present in Kurloff cells (KC). KC AcPase were extracted, with similar yields, either with non-ionic detergent solution or after Dounce homogenization in low ionic strength buffer suggesting that they mainly correspond to hydrosoluble AcPase. After DEAE-cellulose chromatography of such crude Dounce-extracts, 97% of KC AcPase activity was recovered in the unbound glycoprotein fraction (peak I). The main protein content consisted of, as testified by SDS-PAGE analysis, major KC glycoproteins of 30–35 kDa. Thus, KC AcPase, and particularly sialoAcPase, may be assumed to correspond to these N-glycosylproteins among which the presence of α(2,6) sialoglycoproteins was previously established. Following electrophoresis on a 4–15% gradient native polyacrylamide gel or isoelectric focusing, the two size populations (200 kDa and 500 kDa) and up to 20 isoforms of KC AcPase were respectively detected by zymography in peak I. After Clostridium-derived sialidase digestion of peak I, the highly active bands observed at pH 3.5 – 5.2 disappeared. These zymographic patterns were similar to those obtained with crude extracts. After Concanavalin A (ConA)-Sepharose chromatography of peak I, the single ConA-bound glucosamine-labelled peak, eluted at 200 methyl-α-d-mannopyranose, contained the AcPase activity while the ConA-unbound peak was devoid of any acid phosphatase activity. After SDS-PAGE analysis, the ConA-bound fraction appeared to correspond only to a single broad protein band in the 30–35 kDa zone. The Sambucus nigra agglutinin-reactivity of the latter band confirmed the α(2,6) sialylation pattern of KC AcPase. Moreover, their strong binding to ConA-Sepharose suggests that they could only correspond to the hybrid type of the N-glycosylproteins, since they could not correspond to the oligomannosidic type considering the absence of Galanthus nivalis agglutinin-positive structures.  相似文献   

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Two new species of the new genus Athaumaspis gen. n., Athaumaspis minutus sp. n. and Athaumaspis tibetanus sp. n. from Vietnam and China are described. The subgenus Pseudothaumaspis of Thaumaspis is elevated to generic status and another two new species Pseudothaumaspis bispinosus sp. n. and Pseudothaumaspis furcocercus sp. n. are described, the remaining species of Thaumaspis are reviewed and keyed with the four new species.  相似文献   

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In November 1975, as the first in the Netherlands, a full-time psychologist was employed at the Department of Cardiology of the Thoraxcenter of the Erasmus Medical Center. This innovative decision was consistent with a view to treat the patient as a whole rather than the heart as a single body part in need of repair, combined with the understanding that the heart and mind interact to affect health. The present selective review addresses the broad range of contributions of 35 years of psychology to clinical cardiology and cardiovascular research with a focus on research, teaching, psychological screening and patient care. The review ends with lessons to be learned and challenges for the future with respect to improving the care and management of patients with heart disease in order to enhance secondary prevention and the role of behavioural and psychological factors in this endeavour.  相似文献   

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The limbs of extant terrestrial vertebrates possess five or fewer digits, yet, polydactyly is accepted as being the ancestral state. Therefore, I propose a hypothesis to account for the maintenance of digital number at five or fewer digits, based on a selective disadvantage associated with polydactylous states in terrestrial vertebrates. This disadvantage is not associated with the polydactyly per se, but rather with the hemimelia which is a common feature of polydactylies in mammals. Hemimelia causes a twisting, or luxation, of the distal segment of the limb, which is due to a malformation of the radius/tibia of the limb. This defect results in the limb being held in an abnormal gait, which causes problems in the locomotion of the animal which would compromise their ability to flourish. Therefore, the abnormal gait and torsion of the limb caused by the hemimelia is acting as a stabilizing force to maintain the dactyly of the tetrapod limb with five or fewer digits.  相似文献   

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The complete 15,831 bp nucleotide sequence of the mitochondrial genome from Elimaea cheni(Phaneropterinae)was determined.The putative initiation codon for cox1 was TTA.The phylogeny of Orthoptera based on different mtDNA datasets were analyzed with maximum likelihood(ML)and Bayesian inference(BI).When all 37 genes(mtDNA)were analyzed simultaneously,the monophyly of Caelifera and Ensifera were recovered in the context of our taxon sampling.The phylogeny of Orthoptera was largely consistent with previous phylogenetie hypotheses.Rhaphidophoridae to be a sister group of Tettigoniidae,and the relationships among four subfamilies of Tettigoniidae were(Phaneropterinae+(Conocephalinae+(Bradyporinae+Tettigoniinae))).Pyrgomorphidae was the most basal group of Caelifera.The relationships among six acridid subfamilies were(Oedipodinae+(Acridinae+(Gomphocerinae+(Oxyinae+(Calliptaminae +Cyrtacanthaeridinae))))).However,we did not recover a monophyletic Grylloidea.Myrmecophilidae clustered into one clade with Gryllotalpidae instead of with Gryllidae.ML and BI analyses of all protein coding genes(using all nucleotide sequence data or excluding the third codon position,and amino acid sequences)revealed a topology identical to that of the entire mtDNA genome dataset.However,22 tRNAs genes excluding the DHU loop and T()C loop(TRNA),and two rRNA genes(RRNA)perform poorly when analyzed as single dataset.Our results suggest that the best phylogenetie inferences were ML and BI methods based on total mtDNA.Excluding tRNA genes,rRNA genes and the third codon position of protein coding genes from dataset and converting nucleotide sequences to amino acid sequences do not positively affect phylogenetic reconstruction.  相似文献   

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Molecular Biology Reports - Breast Cancer is the most frequent neoplasm diagnosed among women worldwide. Genetic background and lifestyle/environment play a significant role in the disease...  相似文献   

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The majority of the 1H NMR resonances of the protons in a tetradecamer containing the —35 region of the trp promoter d(GCTGTTGACAATTA): d(TAATTGTCAACAGC) and in the TA transversion have been assigned. The conformational properties of the nucleotides have been determined and compared in the two duplexes. Analysis of spin-spin coupling and NOES shows that all sugar puckers are in the south domain (i.e. near C2 endo) and the glycosidic torsion angles are anti (110°). The NMR data are consistent with the duplex being in the B family of conformations. Significant differences in chemical shifts between the two molecules were observed only for nearest neighbours to the transversion site, suggesting the absence of long range conformational effects. This was confirmed by the similarity of coupling constants and NOEs. Other properties are also not greatly affected at positions more than two base pairs from the mutation site. These results are consistent with the hypothesis that unconstrained oligonucleotides are highly flexible, and can readily accommodate significant perturbations of the local structure, such as a transversion.  相似文献   

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Aβ self-assembles into parallel cross-β fibrillar aggregates, which is associated with Alzheimer''s disease pathology. A central hairpin turn around residues 23–29 is a defining characteristic of Aβ in its aggregated state. Major biophysical properties of Aβ, including this turn, remain unaltered in the central fragment Aβ18–35. Here, we synthesize a single deletion mutant, ΔG25, with the aim of sterically hindering the hairpin turn in Aβ18–35. We find that the solubility of the peptide goes up by more than 20-fold. Although some oligomeric structures do form, solution state NMR spectroscopy shows that they have mostly random coil conformations. Fibrils ultimately form at a much higher concentration but have widths approximately twice that of Aβ18–35, suggesting an opening of the hairpin bend. Surprisingly, two-dimensional solid state NMR shows that the contact between Phe19 and Leu34 residues, observed in full-length Aβ and Aβ18–35, is still intact in these fibrils. This is possible if the monomers in the fibril are arranged in an antiparallel β-sheet conformation. Indeed, IR measurements, supported by tyrosine cross-linking experiments, provide a characteristic signature of the antiparallel β-sheet. We conclude that the self-assembly of Aβ is critically dependent on the hairpin turn and on the contact between the Phe19 and Leu34 regions, making them potentially sensitive targets for Alzheimer''s therapeutics. Our results show the importance of specific conformations in an aggregation process thought to be primarily driven by nonspecific hydrophobic interactions.  相似文献   

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The origin of life is an extraordinary problem that leads back to the structure and dynamics of the cosmos and early development of organic molecules. Within that wider question lies an unsolved problem that has troubled biologists for 150 years. What is the origin of the dominant presence of left-handed stereoisomers of amino acids in nature even though their synthesis normally results in an equal mixture of the right- and left-handed molecular forms? We propose that asymmetric Earth rotation caused at dawn and dusk circularly polarized UV light (CPUVL) of opposite polarity and reversed temperature profiles in the oceans. Destruction of the d-isomer by CPUVL at dusk in a sea surface hotter than at dawn created a daily l-isomer excess protected from radiation by nightfall, preserved by down-flow (diffusive, mechanical) into cold, darker regions, eventually initiating an l-amino-acid excess embodied in early marine forms. Innumerable mechanisms have been proposed for the origin of l-chiral dominance in amino acids and none proven. Since the thalidomide tragedy, homochirality of amino acids has been a growing practical issue for medicine. Understanding its origin may bring further and unexpected benefits. It may also be a modest pointer to the possibility of positive answers to whether intelligent life will have the capacity to continue to protect itself from conditions inimical to survival.  相似文献   

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Littorals in the in the Exuma Cays, Bahamas and the Bath Plantation, Barbados are comparative in many ways. These edges of the sea have provided critical services to local people during the time of slavery and since. More than food and medicine, the littoral is the nightly sea bath, where children are instructed, and the last ecosystem effectively used by the elderly. Independence and self-respect derive from use and protection of these littoral by individuals and communities. Local patterns of conservation and use are argued to be essential in the ecological structure and functions of the littoral. Development projects and marine protected areas alike are seen as potentially breaking local ties with the littoral causing trophic skew and damaging local society. If development occurs, mitigation solutions potentially derive from legally recognizing local people as partners in the co-management of their traditional littoral.
Richard W. Stoffle (Corresponding author)Email:
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The German site of Geißenklösterle is crucial to debates concerning the European Middle to Upper Palaeolithic transition and the origins of the Aurignacian in Europe. Previous dates from the site are central to an important hypothesis, the Kulturpumpe model, which posits that the Swabian Jura was an area where crucial behavioural developments took place and then spread to other parts of Europe. The previous chronology (critical to the model), is based mainly on radiocarbon dating, but remains poorly constrained due to the dating resolution and the variability of dates. The cause of these problems is disputed, but two principal explanations have been proposed: a) larger than expected variations in the production of atmospheric radiocarbon, and b) taphonomic influences in the site mixing the bones that were dated into different parts of the site. We reinvestigate the chronology using a new series of radiocarbon determinations obtained from the Mousterian, Aurignacian and Gravettian levels. The results strongly imply that the previous dates were affected by insufficient decontamination of the bone collagen prior to dating. Using an ultrafiltration protocol the chronometric picture becomes much clearer. Comparison of the results against other recently dated sites in other parts of Europe suggests the Early Aurignacian levels are earlier than other sites in the south of France and Italy, but not as early as recently dated sites which suggest a pre-Aurignacian dispersal of modern humans to Italy by ∼45000 cal BP. They are consistent with the importance of the Danube Corridor as a key route for the movement of people and ideas. The new dates fail to refute the Kulturpumpe model and suggest that Swabian Jura is a region that contributed significantly to the evolution of symbolic behaviour as indicated by early evidence for figurative art, music and mythical imagery.  相似文献   

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