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C. Giles Miller 《ZooKeys》2016,(550):71-81
Sherborn’s work on the Foraminifera clearly provided the initial spark to compile the major indexes for which he is famous. Contact and help from famous early micropalaeontologists such as T. Rupert Jones and Fortescue William Millett led Sherborn to produce his Bibliography of Foraminifera and subsequently a two-part Index of Foraminiferal Genera and Species. Edward Heron-Allen, whose mentor was Millett, was subsequently inspired by the bibliography to attempt to acquire every publication listed. This remarkable collection of literature was donated to the British Museum (Natural History) in 1926 along with the foraminiferal collections Heron-Allen had mainly purchased from early micropalaeontologists. This donation forms the backbone of the current NHM micropalaeontological collections. The NHM collections contain a relatively small amount of foraminiferal material published by Sherborn from the London Clay, Kimmeridge Clay and Speeton Clay. Another smaller collection reflects his longer-term interest in the British Chalk following regular fieldwork with A. W. Rowe. Other collections relating to Sherborn’s early published work, particularly with T. R. Jones, are not present in the collections but these collections may have been sold or deposited elsewhere by his co-workers. 相似文献
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Paul D. N. Hebert Jeremy R. deWaard Evgeny V. Zakharov Sean W. J. Prosser Jayme E. Sones Jaclyn T. A. McKeown Beth Mantle John La Salle 《PloS one》2013,8(7)
DNA barcoding protocols require the linkage of each sequence record to a voucher specimen that has, whenever possible, been authoritatively identified. Natural history collections would seem an ideal resource for barcode library construction, but they have never seen large-scale analysis because of concerns linked to DNA degradation. The present study examines the strength of this barrier, carrying out a comprehensive analysis of moth and butterfly (Lepidoptera) species in the Australian National Insect Collection. Protocols were developed that enabled tissue samples, specimen data, and images to be assembled rapidly. Using these methods, a five-person team processed 41,650 specimens representing 12,699 species in 14 weeks. Subsequent molecular analysis took about six months, reflecting the need for multiple rounds of PCR as sequence recovery was impacted by age, body size, and collection protocols. Despite these variables and the fact that specimens averaged 30.4 years old, barcode records were obtained from 86% of the species. In fact, one or more barcode compliant sequences (>487 bp) were recovered from virtually all species represented by five or more individuals, even when the youngest was 50 years old. By assembling specimen images, distributional data, and DNA barcode sequences on a web-accessible informatics platform, this study has greatly advanced accessibility to information on thousands of species. Moreover, much of the specimen data became publically accessible within days of its acquisition, while most sequence results saw release within three months. As such, this study reveals the speed with which DNA barcode workflows can mobilize biodiversity data, often providing the first web-accessible information for a species. These results further suggest that existing collections can enable the rapid development of a comprehensive DNA barcode library for the most diverse compartment of terrestrial biodiversity – insects. 相似文献
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The Academy of Natural Sciences of Philadelphia (ANSP) houses the world’s most comprehensive collection of Rotifera on microscope slides. A particular strength of this major reference collection and type repository lies in the excellent preparation of specimens in life-like extended state and its balanced coverage of the phylum. The collection is almost worldwide in scope, and currently comprises 774 valid taxa, equalling a taxon coverage of 88.2% (families), 75.4% (genera), and 39.1% (species) compared to taxon numbers currently known to occur worldwide. A searchable database plus illustrated catalog has now been published on CD-ROM and on the Academy’s website. The poor representation of Rotifera in natural history collections and their generally poor curation and conservation is commented upon. 相似文献
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Alagona PS 《Journal of the history of biology》2012,45(4):651-680
In 1937 Joseph Grinnell founded the University of California's (U.C.) first biological field station, the Hastings Natural History Reservation. Hastings became a center for field biology on the West Coast, and by 1960 it was serving as a model for the creation of additional U.C. reserves. Today, the U.C. Natural Reserve System (NRS) is the largest and most diverse network of university-based biological field stations in the world, with 36 sites covering more than 135,000 acres. This essay examines the founding of the Hastings Reservation, and asks how it managed to grow and develop, in the 1940s and 1950s, during a time of declining support for natural history research. It shows how faculty and staff courted the support of key institutional allies, presented themselves as the guardians of a venerable tradition in nature study, and emphasized the station's capacity to document ecological change and inform environmental policy and management. In the years since, Hastings and other U.C. reserves have played crucial roles in California environmental politics. Biological field stations in the post-war era deserve more attention not only from historians of biology, but also from environmental historians and other scholars interested in the role of science in society. 相似文献
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《Comptes Rendus Palevol》2002,1(6):335-345
D’Orbigny’s stratigraphic contributions were enormous, both practical and theoretical. In his practice, d’Orbigny realised the central importance of using fossil faunas to correlate strata across different countries. His ‘succession chronologique des âges du monde’ (of 1852) recognised 5 periods and 27 stages (ignoring his ‘époque actuelle’). The great majority of the latter were from two Periods, Jurassic (stages 7 to 16) or Cretaceous (17 to 23). D’Orbigny described the palaeontological characteristics, and geographical extensions, of each. Some stages he based on countries he never visited and although he never specified ‘stratotype’ localities, he referred to some as ‘étalon’, ‘le mieux’ or ‘le plus beau’. These leads proved crucial when, in the mid 20th century, stratigraphers realised that definitions of chrono-stratal units must be attempted. The first attempts at typification simply followed zoology, where a type specimen tries to define a central position within the morphological variation of a species. In 1962, an early attempt was made to define Jurassic stages by three type horizons at different type localities (or stratotypes as they were now called) for each. A central horizon was chosen as ‘lectotype section’ and upper and lower boundaries for each were defined elsewhere. In France, it was preferred to investigate original intentions at named localities, through unit-stratotypes. These allowed some nationalistic pride, since France was the home of so many d’Orbignyan stages. 1980 saw the publication Les Étages français et leurs Stratotypes. However, British Silurian stratigraphers had realised that such zoologically based concepts would produce conflict, when any defined upper boundary stratotype conflicted with the defined lower boundary of a superjacent unit. They suggested, from 1962, to define only lower boundaries, via ‘golden spikes’, at basal-boundary stratotypes. This was the method chosen for the basal Devonian stratotype at Klonk, Czech Republic, defined in 1972, and a method adopted globally from 1986. However, this was when correlations were still largely based on fossils. The explosion of so many other stratigraphies since, based on magnetic or chemical records, events etc, has produced a first reaction against the idea that such stratotypes should be so defined, while a second, potentially more major claim, is that any ‘golden spike’ concept may no longer ‘glitter’, as competing stratotype concepts may be holding back stratigraphic progress. 相似文献
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Nigel Eltringham 《Ethnos》2013,78(3):425-445
While the ethnography of contemporary courtrooms has been dominated by a concern with speech, this article considers how a silent, validating public is constructed within court complexes. Drawing on fieldwork at the International Criminal Tribunal for Rwanda (Arusha, Tanzania), I explore how the court's threshold practices form validating witnesses whose embodied deference contributes to the constitution of the courtroom as a space of privileged speech. I suggest, therefore, that court spectators are not incidental, but are integral to juridical spectacle and the authority of law. 相似文献
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Seven species of Centrorhynchus Lühe, 1911 are present in the Parasitic Worms Collection of The Natural History Museum, London: C. aluconis (Müller, 1780) Lühe, 1911 from Strix aluco Linnaeus in Great Britain; C. buteonis (Schrank, 1788) Kostylev, 1914 from Accipiter virgatus (Temminck) (new host record) in Sri Lanka (new geographical record); C. clitorideus (Meyer, 1931) Golvan, 1956 from Athene brama (Temminck) (new host record) in India; C. crotophagicola Schmidt & Neiland, 1966 (encysted juveniles in the stomach wall) from Anolis lineatopus Grey (new host record) and A. sagrei Duméril & Bibron (new host record) from Jamaica (new geographical record); C. falconis (Johnston & Best, 1943) Golvan, 1956 from Spilornis cheela (Latham) in Sri Lanka (new geographical record); C. globocaudatus (Zeder, 1800) Lühe, 1911 from Falco ardosiaceus Vieillot (new host record) in West Africa; and C. milvus Ward, 1956 from Milvus migrans (Boddaert) in India. The species are described and figured on the basis of this material. 相似文献
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Maria Ntinou Ernestina Badal Yolanda Carrión José Luis Menéndez Fueyo Roberto Ferrer Carrión Joaquín Pina Mira 《Vegetation History and Archaeobotany》2013,22(2):115-128
Excavations on the Rock of Ifach, Alicante, Spain have revealed the remains of a medieval settlement that flourished between a.d. 1297 and 1359. Wood charcoal analysis combined with archaeological evidence and historical records allow an assessment of the local vegetation of the area during the medieval period, the obtaining and use of firewood and the commercial routes for supplying timber. Pinus halepensis and to a lesser degree various matorral taxa were used for fuel during the main occupation phases at the settlement. The resource exploitation network of the settlement expanded over the adjacent coastal area, with firewood obtained from pine woodlands there. The timbers used in the construction of the settlement were mainly from pines that originated nearby (P. halepensis) or which were transported by river from woodland areas to the north which were controlled by the Crown of Aragon (P. nigra/sylvestris, P. pinaster). The partial destruction of the village in a.d. 1359 and its gradual abandonment are reflected in changes observed in fuel supplying practices that then concentrated on the local matorral vegetation of the rock itself. 相似文献
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The mammary gland response to estradiol: monotonic at the cellular level, non-monotonic at the tissue-level of organization? 总被引:1,自引:0,他引:1
Vandenberg LN Wadia PR Schaeberle CM Rubin BS Sonnenschein C Soto AM 《The Journal of steroid biochemistry and molecular biology》2006,101(4-5):263-274
The role of hormones in mammary gland development has been studied in detail using surgical and genetic models. These studies have indicated roles for estrogen in ductal elongation and terminal end bud formation. However, no comprehensive study has quantified how different doses of estrogen affect morphological parameters of mammary gland development. Additionally, comparisons between the estrogen-responsiveness of the mammary gland and uterus, the model organ for estrogen action are incomplete. In this study, immature mice were ovariectomized and implanted with osmotic pumps releasing one of eight doses of 17β-estradiol for 10 days. As expected from the classical uterotrophic assay, the uterus showed a monotonic dose–response curve for all measured endpoints. In contrast, the mammary gland showed a non-monotonic, inverted-U shaped response to estrogen with regard to morphometric parameters, and a monotonic response with regard to gene expression parameters. These results indicate that estrogen has opposing effects in mammary gland morphogenesis depending on estrogen dose, i.e. low to moderate doses induce terminal end bud formation and ductal elongation while higher doses inhibit these processes. This non-monotonic dose–response in the mammary gland may reflect complex interactions, where estrogen can act on multiple targets either as an agonist or antagonist. 相似文献
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《L'Anthropologie》2023,127(2):103134
The most abundant evidence of Pampean Pleistocene human presence are modified bones, as lithic procurement sites located farther than 300 km away. Therefore, we focused on the study of bone modifications, in particular cut and percussion marks. We studied Pampean paleontological collections of Argentine and European museums as an alternative resource of previously unnoticed human modification evidences. We compared marks characteristics with those of archaeological collections from diverse climatic and cultural adaptations, from middle Pleistocene sites (Vallonet, Atapuerca, Lazaret, Arago and Terra Amata) to terminal Pleistocene ones (Abri Pataud, Isturiz and La Vache). Marks typologies were defined, leading to the identification of a particular cutmark that we named double parallel considered as highly diagnostic of anthropic use of lithic artifacts. We also propose that hafted artifacts were used on carcass processing. Perimortem bone modifications are classified in relation with mark morphology (e.g., percussion striae), inferred gesture or action (e.g., breakage of diaphysis), and inferred objective of that action (e.g., marrow extraction). The megafauna specimens analyzed from the historical collections (d’Angelis-Vilardebó, 1847, Muñiz-Dupotet, 1842 and Breton-Bonnement, 1881) present modifications compatible with dismemberment, defleshing, tongue and masseter extraction, and utilization as anvils. The lack of contextual data (location, stratigraphy) and the loss due to museum selection/collecting of accompanying material prevent paleoenvironmental and paleoecological inferences. Regional geology indicates that most of the historical collections were exhumed in riverbank cuts with ages between 70 and 13 ky BP. Preliminary direct dating presents evidence of a Pampean human occupation, at least, since OIS 2. 相似文献
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We present the 2.6 A resolution crystal structure of a complex formed between G-actin and gelsolin fragment Met25-Gln160 (G1+). The structure differs from those of other gelsolin domain 1 (G1) complexes in that an additional six amino acid residues from the crucial linker region into gelsolin domain 2 (G2) are visible and are attached securely to the surface of actin. The linker segment extends away from G1 up the face of actin in a direction that infers G2 will bind along the same long-pitch helical strand as the actin bound to G1. This is consistent with a mechanism whereby G2 attaches gelsolin to the side of a filament and then directs G1 toward a position where it would disrupt actin-actin contacts. Alignment of the sequence of the structurally important residues within the G1-G2 linker with those of WH2 (WASp homology domain 2) domain protein family members (e.g. WASp (Wiscott-Aldridge syndrome protein) and thymosin beta4) suggests that the opposing activities of filament assembly and disassembly may exploit a common patch on the surface of actin. 相似文献
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Parkinson’s disease (PD) is the most common movement disorder. The neuropathology is characterized by the loss of dopamine
neurons in the substantia nigra pars compacta. Transplants of fetal/embryonic midbrain tissue have exhibited some beneficial
clinical effects in open-label trials. Neural grafting has, however, not become a standard treatment for several reasons.
First, the supply of donor cells is limited, and therefore, surgery is accompanied by difficult logistics. Second, the extent
of beneficial effects has varied in a partly unpredictable manner. Third, some patients have exhibited graft-related side
effects in the form of involuntary movements. Fourth, in two major double-blind placebo-controlled trials, there was no effect
of the transplants on the primary endpoints. Nevertheless, neural transplantation continues to receive a great deal of interest,
and now, attention is shifting to the idea of using stem cells as starting donor material. In the context of stem cell therapy
for PD, stem cells can be divided into three categories: neural stem cells, embryonic stem cells, and other tissue-specific
types of stem cells, e.g., bone marrow stem cells. Each type of stem cell is associated with advantages and disadvantages.
In this article, we review recent advances of stem cell research of direct relevance to clinical application in PD and highlight
the pros and cons of the different sources of cells. We draw special attention to some key problems that face the translation
of stem cell technology into the clinical arena. 相似文献
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The phytopathogenic bacterium Ralstonia solanacearum encodes type III effectors, called GALA proteins, which contain F-box and LRR domains. The GALA LRRs do not perfectly fit any of the previously described LRR subfamilies. By applying protein sequence analysis and structural prediction, we clarify this ambiguous case of LRR classification and assign GALA-LRRs to CC-LRR subfamily. We demonstrate that side-by-side packing of LRRs in the 3D structures may control the limits of repeat variability within the LRR subfamilies during evolution. The LRR packing can be used as a criterion, complementing the repeat sequences, to classify newly identified LRR domains. Our phylogenetic analysis of F-box domains proposes the lateral gene transfer of bacterial GALA proteins from host plants. We also present an evolutionary scenario which can explain the transformation of the original plant LRRs into slightly different bacterial LRRs. The examination of the selective evolutionary pressure acting on GALA proteins suggests that the convex side of their horse-shoe shaped LRR domains is more prone to positive selection than the concave side, and we therefore hypothesize that the convex surface might be the site of protein binding relevant to the adaptor function of the F-box GALA proteins. This conclusion provides a strong background for further functional studies aimed at determining the role of these type III effectors in the virulence of R. solanacearum. 相似文献
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Rodolfo Alejandro Hernández Corchado 《Dialectical Anthropology》2018,42(2):179-191
Since the late 1980s, indigenous Mixtecos of the Montaña region, in the southern state of Guerrero, Mexico, have become new members of the Mexican migrant working class in New York City (NYC). This article examines the contemporary history of proletarianization via migration of the Mixtecos of the Montaña. It shows to what extent the region became a supplier of migrant labor, and how its inhabitants transitioned from peasants and semi-proletarians of Mexico’s northwest agribusinesses to transnational migrant proletarians, as a result of major regional transformations related to state violence and drug cartel penetration. Indigenous Mixtecos have endured social inequality, racism, and state violence from post-revolutionary to contemporary neoliberal governments in Guerrero. Before their migration to NYC, they have gone through different rounds of proletarianization which differ from the Mexican mestizo migrant flow. The article aims to contribute to unravel such particularities, which have been subsumed as part of a homogeneous pattern in the history of Mexican migration and proletarianization in NYC.Based on ethnographic research conducted for my doctoral dissertation (2014) and using oral history, the article traces, through the life story of a Mixteco migrant worker, the different rounds of dispossession in the history of proletarianization of Mixteco indigenous migrants from the Montaña. 相似文献
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T. N. Smirnova 《Paleontological Journal》2012,46(12):1350-1357
The study of rich rhynchonellid assemblage, collected by layers in the Early Cretaceous deposits of Dagestan, revealed sharp morphological changes of the assemblages at the Barremian-Aptian boundary; the shell exterior and almost all endoskeletal structures changed. The study of morphogenesis of the Late Mesozoic rhynchonellids revealed that boundary in the development of main shell structures during Middle Jurassic-Maastrichtian interval is also in the middle of Early Cretaceous. 相似文献