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1.
A convergence of evidence from macroscopic, radiographic and histologic examination indicates that treponemal infection was present in the 16ST1 Tchefuncte Indian burial population, dated 500 B.C. to 300 A.D. Pattern and nature of lesions suggests that chronic infection induced by variants of the spirochete Treponema pallidum, causing endemic syphilis and/or yaws, resulted in third-stage osseous response. It is suggested that Tchefuncte Indians acquired partial immunity to treponemal infection by exposure to a variant of the related spirochete, Borrelia burgdorferi, the causative agent of Lyme disease. Partial immunity would help explain the relatively mild expression of the treponemal disease process in the 16ST1 skeletal population and the apparent absence of venereal syphilis. Presence of the Borrelia burgdorferi spirochete might be linked to a single incidence of juvenile rheumatoid arthritis. © 1994 Wiley-Liss, Inc.  相似文献   

2.
The spirochete Treponema pallidum is the causative agent of syphilis, a sexually transmitted infection of major global importance. Other closely related subspecies of Treponema also are the etiological agents of the endemic treponematoses, such as yaws, pinta, and bejel. The inability of T. pallidum and its close relatives to be cultured in vitro has prompted efforts to characterize T. pallidum's proteins structurally and biophysically, particularly those potentially relevant to treponemal membrane biology, with the goal of possibly revealing the functions of those proteins. This report describes the structure of the treponemal protein Tp0737; this polypeptide has a fold characteristic of a class of periplasmic ligand‐binding proteins associated with ABC‐type transporters. Although no ligand for the protein was observed in electron‐density maps, and thus the nature of the native ligand remains obscure, the structural data described herein provide a foundation for further efforts to elucidate the ligand and thus the function of this protein in T. pallidum.  相似文献   

3.
The Italian hare (Lepus corsicanus) is an endangered species whose natural populations have decreased in recent years. This study’s objective was to identify ticks infesting hares and their habitats in a wildlife reserve in southern Italy. In June 2009, ticks were collected by dragging in three transects set in a meadow habitat within an enclosure inhabited by hares and in three similar transects outside this enclosure. Fifty-five ticks were collected by dragging, being 54 inside and 1 outside the enclosure. Ticks were identified as Hyalomma marginatum (34 males, 17 females), Dermacentor marginatus (2 males, 1 female), and Rhipicephalus bursa (1 female). In September 2009, ticks were collected from 17 Italian hares and identified as Ixodes ricinus (2 larvae, 45 nymphs, 35 males, 37 females), Rhipicephalus turanicus (2 males, 1 nymph), and Hyalomma sp. (165 nymphs). PCR amplification and sequencing of a partial region of the 12S rDNA gene of Hyalomma nymphs allowed their identification as H. marginatum. This study suggests that host presence is a factor determining the level of environmental tick infestation as well as the free-living tick species in the study area and that Italian hares are hosts for I. ricinus and H. marginatum. Studies to assess whether these ticks could limit the survival and fitness of Italian hares and affect their conservation status are needed. Moreover, it is necessary to investigate whether these ticks are infected with pathogens of medical and veterinary concern.  相似文献   

4.
Owl predation on snowshoe hares: consequences of antipredator behaviour   总被引:4,自引:0,他引:4  
We show evidence of differential predation on snowshoe hares (Lepus americanus) by great horned owls (Bubo virginianus) and ask whether predation mortality is related to antipredator behaviour in prey. We predicted higher predation on (1) young and inexperienced hares, (2) hares in open habitats lacking cover to protect from owl predation, and (3) hares in above average condition assuming that rich food patches are under highest risk of predation. Information on killed hares was obtained at nest sites of owls and by monitoring hares using radio-telemetry. The availability of age classes within the hare population was established from live-trapping and field data on reproduction and survival. Great horned owls preferred juvenile over adult hares. Juveniles were more vulnerable to owl predation before rather than after dispersal, suggesting that displacement or increased mobility were not causes for this increased mortality. Owls killed ratio-collared hares more often in open than in closed forest types, and they avoided or had less hunting success in habitats with dense shrub cover. Also, owls took hares in above average condition, although it is unclear whether samples from early spring are representative for other seasons. In conclusion, these results are consistent with the hypothesis that variation in antipredator behaviours of snowshoe hares leads to differential predation by great horned owls.  相似文献   

5.
Treponema pallidum and the quest for outer membrane proteins   总被引:6,自引:1,他引:5  
Treponema pallidum, the syphilis spirochaete, has a remarkable ability to evade the humoral and cellular responses it elicits in infected hosts. Although formerly attributed to the presence of an outer coat comprised of serum proteins and/or mucopolysaccharides, current evidence indicates that the immuno-evasiveness of this bacterium is largely the result of its unusual molecular architecture. Based upon a combination of molecular, biochemical, and ultrastructural data, it is now believed that the T. pallidum outer membrane (OM) contains a paucity of poorly immunogenic transmembrane proteins (‘rare outer membrane proteins’) and that its highly immunogentc proteins are lipoproteins anchored predominantly to the periplasmic leaflet of the cytoplasmic membrane. The presence in the T. pallidum OM of a limited number of transmembrane proteins has profound implications for understanding syphilis pathogenesis as well as treponemal physiology. Two major strategies for molecular characterization of rare outer membrane proteins have evolved. The first involves the identification of candidate OM proteins as fusions with Escherichia coli alkaline phosphatase. The second involves the characterization of candidate OM proteins identified in outer membranes isolated from virulent T. pallidum. Criteria to define candidate OM proteins and for definitive identification of rare OM proteins are proposed as a guide for future studies.  相似文献   

6.
In this study we accumulate evidence that brown hare competes with brent goose for food resources in a temperate salt marsh. We show that both species overlap in habitat use and share food plants. The two herbivores mainly used the common habitat at different times of the day, with hares active in the dark and geese during the daylight. During the morning and evening, however, the habitat was exploited simultaneously. Food availability was manipulated by excluding brent geese on both small-scale (30 m2) and large-scale (0.96 ha) plots, while hares had free access everywhere. Exclusion of brent geese enhanced the level of utilisation by hares in both Festuca and Puccinellia dominated marshes, which are among the most intensively grazed parts of the salt marsh. The increase in hare grazing pressure following goose exclusion was stronger, when the adjacent control plots had attracted more goose visitation. When geese were excluded, the decrease in Festuca consumption by geese was completely matched by increased hare grazing, while for Puccinellia only part of the `surplus' was harvested. Enhanced levels of hare utilisation were not due to geese interfering directly with hare, nor due to hares avoiding goose droppings. Considering the interaction from the other perspective, hares were observed to disturb geese effectively in every spring. This might have reduced exploitation by geese of the shared resources. On the basis of our experimental results, we conclude that in this salt- marsh system competition for food with brent geese plays a role in the habitat use of hares, and that hares can reduce goose exploitation of shared habitats. Received: 30 March 1998 / Accepted: 6 July 1998  相似文献   

7.
Among the European fauna, the Sardinian hare (Lepus sp.) is peculiar in that it differs from all other hares inhabiting the continent. Here, we report on the variation of a 461 bp sequence of hypervariable domain 1 of the mitochondrial control region, examined in 42 hares collected throughout Sardinia and compared to the corresponding sequences of different Lepus taxa. Seventeen novel haplotypes were found in the Sardinian population, resulting in a haplotype diversity of 0.840 and a nucleotide diversity of 0.012. As a result of Bayesian and principal coordinates analyses, Sardinian hares were grouped with North African hares, constituting a monophyletic clade that diverges from all other Old World hares, including Cape hares from South Africa and East Asia. Hence, our data agree that populations inhabiting North Africa and Sardinia form a distinct taxon, which could possibly be included in the L. capensis superspecies. Moreover, two corresponding lineages can be found in Sardinia and Tunisia, providing evidence of a common origin of the two populations and thus supporting the hypothesis that North African hares were introduced into the island in historical times. Our data show that the two lineages differ in their geographic distribution throughout the island and that the wild Sardinian population also shows the signature of a postintroduction demographic expansion.  相似文献   

8.
150 serum samples (reactive in VDRL, Reiter-ELISA, FTA-Abs tests), from male patients 25-45 years old, in various stages of syphilis whether treated or untreated, were tested for IgD by SRID. On 154 sera from healthy males 25-45 years old, the reference normal values for IgD levels were established, as: 0-131.2 IU/ml with a mean of 29.92 +/- 29.61 IU/ml. Cardiolipin and group treponemal fraction values for IgD class were obtained by assessing the difference between the immunodiffusion diameter values produced by sera before and after complete absorption with VDRL antigen or delipidated T. reiteri suspension. The individual, mean +/- SD values (expressed in IU/ml) and the percentage of cardiolipin and treponemal IgD of the total IgD class were calculated for each stage. The mean value of the total IgD class, excepting secondary syphilis (sigma 2) 52.53 +/- 26.66 IU/ml), did not overstep the normal levels but all minimal individual values from syphilitic patients (7.09-14.89 IU/ml) surpassed significantly the normal minimal values which were less than or equal to 3.54 IU/ml. The total lack of cardiolipin (IgD and the presence of group treponemal IgD in all sera of the syphilis stages studied were manifest. The group treponemal IgD mean values ranged between 7-9 IU/ml, with a maximum of 19.32 +/- 10.58 IU/ml in sigma 2 followed by latent syphilis (sigma lat) with a mean value of 9.37 +/- 4.9 IU/ml. A significant percentage of treponemal IgD vs total IgD was recorded: primary syphilis (sigma 1) 32.01%, primary-secondary syphilis (sigma 1-2) 28.76%, sigma 2 36.77%, sigma lat and treated persistent seroreactive syphilis (sigma t+) 29.61%. The high proportion of treponemal IgD in latent and treated persistent reactive syphilis suggests a steady activation of B lymphocytes by treponemal antigens and presumably is an expression of an active infectious process. The absence of cardiolipin IgD and the presence of only the treponemal IgD, in all sera from all stages, might confer to their detection an extremely specific diagnostic value in syphilis.  相似文献   

9.
A comparison of current serologic tests for syphilis shows that treponemal tests are preferable to reagin tests in detecting specific antibodies, but that reagin tests are best for determining the response to treatment. The newly developed fta-absorption technique is suggested as a reliable, inexpensive test for treponemal antibodies.  相似文献   

10.
North African hares are currently considered belonging to cape hares (Lepus capensis), except for an isolated occurrence of L. victoriae in NW Algeria. However, the few existing molecular data are not unequivocal. Here, we study sequence variation (415 bp) in the hypervariable domain-1 of the mitochondrial (mt) control region, of hares with different coat colour from north-central Tunisia and NW Egypt, to test Petter's [(1959): Eléments d’une révision des Lièvres africains du sous-genre Lepus. Mammalia 23, 41–67] hypothesis that North African hares belong to L. capensis. Seven Tunisian and one Egyptian haplotypes were revealed from 28 hares and compared phylogenetically to 245 haplotypes of various Lepus species downloaded from GenBank. Neighbour joining (NJ) and principal coordinate (PCO) analyses based on a Tamura-Nei 93 distance matrix, as well as maximum parsimony (MP) analysis concordantly grouped all currently obtained haplotypes together into one monophyletic clade, and revealed relatively close relationships to the clades of African scrub hares (L. saxatilis) and brown hares (L. europaeus). The three distinguished coat colour types of Tunisian hares were paralleled only to a small extent by sequence differentiation. Haplotypes of L. capensis from the nominal Cape province of South Africa, North Africa, and China clustered into different major clades, respectively, with Chinese L. capensis haplotypes forming only a subclade within a major clade that encompassed predominantly “mountain/arctic hare-type sequences” in addition to sequences of several other palaearctic and nearctic species. One further Chinese L. capensis haplotype clustered into the L. comus clade. These results indicated occurrence of introgression and/or shared ancestral polymorphism. Such an evolutionary scenario implies using nucelar markers in addition to mtDNA for phylogenetic inferences in the genus Lepus; nevertheless, mtDNA is still useful for inferring phylogenetic history and biogeography of hares.  相似文献   

11.
Sea hares such as Aplysia californica, gastropod molluscs lacking a protective shell, can release a purple cloud of chemicals when vigorously attacked by predators. This active chemical defense is composed of two glandular secretions, ink and opaline, both of which contain an array of compounds. This secretion defends sea hares against predators such as California spiny lobsters Panulirus interruptus via multiple mechanisms, one of which is phagomimicry, in which secretions containing feeding chemicals attract and distract predators toward the secretion and away from the sea hare. We show here that ink and opaline are highly acidic, both having a pH of ∼5. We examined if the acidity of ink and opaline affects their phagomimetic properties. We tested behavioral and electrophysiological responses of chemoreceptor neurons in the olfactory and gustatory organs of P. interruptus, to ink and opaline of A. californica within their natural range of pH values, from ∼5 to 8. Both behavioral and electrophysiological responses to ink and opaline were enhanced at low pH, and low pH alone accounted for most of this effect. Our data suggest that acidity enhances the phagomimetic chemical defense of sea hares.  相似文献   

12.
The aim of the present study was to examine how the vegetation structure of the forest, shrub and field and ground layer affect the habitat use of mountain haresLepus timidus Linnaeus, 1759 in summer (May–September) in southern Finland. The structure of each vegetation layer in woodlots throughout the entire study area of 20 km2 was measured. We analysed the vegetation data using principal component analyses (PCA) that arranged the woodlots along a gradient within each vegetation layer. Data on habitat use was gathered between 1998 and 2000 from 11 radio-collared mountain hares. The core areas of the home ranges of hares were determined and the vegetation structure of these areas was compared with the mean of the entire study area (core area, periphery area and control area). A similar shrub layer gradient was identified by PCA for seven out of the 11 hares. Hares preferred thickets of willowSalix spp., downy birchBetula pubescens, and sprucePicea abies. The hares did not show a consistent preference for the forest and ground levels. The results suggest that dense understories are important in the mountain hare’s habitat use, probably because they offer both food and shelter.  相似文献   

13.
This report describes a putative case of a treponemal infection observed on a skeleton of a young male adult from the Apple Down Anglo‐Saxon cemetery dating to the sixth century AD, accompanied by grave goods indicative of a high status burial. The skeleton is well preserved and almost complete. The pathological evidence includes an extensive area of lytic destruction to the frontal bone of the skull, widespread profuse bilateral symmetrical periosteal reaction affecting scapulae, clavicles, arms, legs, hands, feet and ribs. There is also evidence of gummatous destruction on some of the long bones. Application of a differential diagnosis of all probable diseases exhibiting the individual symptoms leads to a clear conclusion that the person was infected with a treponemal pathogen. The skeleton shows none of the stigmata associated with the congenital form of treponemal disease. We propose that the evidence suggests a possible case of venereal syphilis rather than one of the endemic forms of treponemal disease. This diagnosis is based on the geographical pathogen range, the apparent low prevalence of the disease, significant social upheaval at the time, the high social status and early age of death of the individual. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   

14.
Allozyme variability of 91 brown hares (Lepus europaeus) from seven regions in Greece was compared to existing data of Bulgarian populations to test the hypothesis of the occurrence of specific alleles in Greece, likely stemming from an isolated Late Pleistocene refugial population in the southern Balkans. This hypothesis is particularly suggested by some subfossil Late Pleistocene hare remains in Greece and the reported high mtDNA diversity in Greek hares. Allozymic diversity could be higher in Greek hares than in hares from neighboring regions as a result of the accumulation of variants in a long-lasting Pleistocene refugium. Conversely, Greek hares could exhibit reduced genetic diversity because of long-lasting low effective population sizes during the Late Glacial Maximum and a lower chance of postglacial gene flow from other populations into this rather marginal part in the southern Balkans. Horizontal starch gel electrophoresis of proteins from 35~loci revealed three alleles (Es-1 –162, Pep-2 114, Mpi 88) at low frequencies, which were not found in Bulgarian or any other brown hare population. In contrast, some alleles from the populations from Bulgaria and other regions of Europe were absent in the Greek samples. Population genetic statistics indicated only a slight tendency of increased gene pool diversity in Greek hares, little substructuring in Greek and Bulgarian populations, respectively, as well as an only slightly lower level of gene flow between the two neighboring regions, as compared to the gene flow within each region. The results conform to the hypothesis of a Late Pleistocene refugial population in the southern Balkans, with some few specific nuclear gene pool characteristics, but little effect on the overall genetic differentiation between Greek and Bulgarian hares.  相似文献   

15.
Abstract: In 1999 Canada lynx (Lynx canadensis) were reintroduced to the southern Rocky Mountains and in 2000 the species was listed as threatened under the Endangered Species Act in the contiguous United States (Colorado Division of Wildlife 2000, U.S. Fish and Wildlife Service 2000). To better evaluate the progress of this reintroduction, we conducted field studies to estimate population densities of snowshoe hares (Lepus americanus), the primary prey of lynx in Colorado, USA. We conducted our field studies in southwestern Colorado in winters 2002 and 2003. We estimated population densities in forested stands of mature Engelmann spruce (Picea engelmannii)-subalpine fir (Abies lasiocarpa) and mature lodgepole pine (Pinus contorta) using mark-recapture data and 3 methods for estimating effective area trapped: half trap interval, mean maximum distance moved (MMDM), and half MMDM. In Engelmann spruce-subalpine fir, we found density estimates ranged from 0.08 ± 0.03 (SE) hares/ha to 1.32 ± 0.15 hares/ha and in lodgepole pine, density estimates ranged from 0.06 ± 0.01 hares/ha to 0.34 ± 0.06 hares/ha, depending on year and method used for estimating effective area trapped. Our density estimates are similar to those reported at the low phase of the hare cycle in populations to the north (<0.1–1.1 hares/ha), where Canada lynx persist (Hodges 2000a). Although density estimates are a useful comparative tool, they depend upon methods used to estimate effective area trapped. Therefore, we urge caution in comparing our density estimates with those from other areas, which may have used dissimilar methods. We also examined effects of temperature and moon phase on capture success of snowshoe hares; extremely low temperatures affected capture success but moon phase did not. Capture success can be improved by trapping snowshoe hares at temperatures above their lower critical temperature (Tlc). If abundance estimates are derived from mark-recapture studies then effects of temperature should be included when modeling capture probabilities.  相似文献   

16.
Two evaluations of the automated fluorescent treponemal antibody (AFTA) test for the serodiagnosis of syphilis are described. The results of AFTA and manually performed fluorescent treponemal antibody-absorption (FTA-ABS) tests were compared on serum samples from clinically defined donor groups, and the reproducibility of each procedure was studied. Significant improvement of AFTA test results was obtained in the most recent study after developmental modifications of the instrument and test technique. AFTA test agreement with both syphilis and nonsyphilis categories was considered good. With the increasing usage of the FTA-ABS test as an effective tool for the diagnosis of syphilis, successful automation of this procedure is particularly timely and significant.  相似文献   

17.
Spatial variation in habitat riskiness has a major influence on the predator–prey space race. However, the outcome of this race can be modulated if prey shares enemies with fellow prey (i.e., another prey species). Sharing of natural enemies may result in apparent competition, and its implications for prey space use remain poorly studied. Our objective was to test how prey species spend time among habitats that differ in riskiness, and how shared predation modulates the space use by prey species. We studied a one‐predator, two‐prey system in a coastal dune landscape in the Netherlands with the European hare (Lepus europaeus) and European rabbit (Oryctolagus cuniculus) as sympatric prey species and red fox (Vulpes vulpes) as their main predator. The fine‐scale space use by each species was quantified using camera traps. We quantified residence time as an index of space use. Hares and rabbits spent time differently among habitats that differ in riskiness. Space use by predators and habitat riskiness affected space use by hares more strongly than space use by rabbits. Residence time of hare was shorter in habitats in which the predator was efficient in searching or capturing prey species. However, hares spent more time in edge habitat when foxes were present, even though foxes are considered ambush predators. Shared predation affected the predator–prey space race for hares positively, and more strongly than the predator–prey space race for rabbits, which were not affected. Shared predation reversed the predator–prey space race between foxes and hares, whereas shared predation possibly also released a negative association and promoted a positive association between our two sympatric prey species. Habitat riskiness, species presence, and prey species’ escape mode and foraging mode (i.e., central‐place vs. noncentral‐place forager) affected the prey space race under shared predation.  相似文献   

18.
Examination of five central Gulf Coast Florida archaeological skeletal series (n = 547) from the late prehistoric and early historic periods reveals the presence of pathological lesions characteristic of treponemal infection. These skeletal remains of native American populations represent a crucial time regarding hypotheses about the exchange of syphilis between the Old and New World or the mutation of one treponemal infection into another. Comparison of the lesions with those observed in modern studies of treponemal infection does not support an interpretation of veneral syphilis. The data from this study and from other archaeological skeletal series indicate the presence of a treponemal disease prior to European contact. The skeletal elements from Florida do not suggest that the disease changed dramatically following contact with Europeans. It is possible that cases of nonspecific postcranial pathology can be explained by the presence of this disease in the Florida populations. This study indicates that a treponemal disease was endemic throughout the region by at least A. D. 1000. © 1993 Wiley-Liss, Inc.  相似文献   

19.
The aim with this study was to, under controlled conditions, determine the food preference of mountain haresLepus timidus Linnaeus, 1758 and bank volesClethrionomys glareolus (Schreber, 1780) for a substantial part of the woody plants potentially available for these herbivores during winter. In addition, we compared hare and vole preference patterns. Thirteen woody plant species were simultaneously presented to 9 captive voles and 9 captive hares in preference tests during winter. Consumption by hares from 50 g bundles (one per species) was measured after 3 h, whereas shoot consumption by voles was measured after 12 h. Both hares and voles preferred deciduous species to conifers,Populus tremula, andVaccinium myrtillus being the most preferred species. However, there was considerable variation in palatability among deciduous plant species and only a marginally significant correlation was found between hare and vole preference. One striking differences between hares and voles was that Sorbusaucuparia was the most utilised by voles but the least preferred by hares. In conclusion, deciduous plant species were generally considerably more palatable to hares and voles than conifers, which is consistent with current theories. Nevertheless, the high variation in palatability among deciduous trees and the difference in preference between hares and voles indicate more complex and species-specific patterns with regard to plant— animal interactions. The latter also suggests that hares and voles differ in their dietary adaptations and have different dietary constrains.  相似文献   

20.
Snowshoe hares (Lepus americanus) are an ecologically important herbivore because they modify vegetation through browsing and serve as a prey resource for multiple predators. We implemented a multiscale approach to characterize habitat relationships for snowshoe hares across the mixed conifer landscape of the northern Rocky Mountains, USA. Our objectives were to (1) assess the relationship between horizontal cover and snowshoe hares, (2) estimate how forest metrics vary across the gradient of snowshoe hare use and horizontal cover, and (3) model and map snowshoe hare occupancy and intensity of use. Results indicated that both occupancy and intensity of use by snowshoe hares increased with horizontal cover and that the effect became stronger as intensity of use increased. This underscores the importance of dense horizontal cover to achieve high use, and likely density, of snowshoe hares. Forest structure in areas with high snowshoe hare use and horizontal cover was characterized as multistoried with dense canopy cover and medium‐sized trees (e.g., 12.7–24.4 cm). The abundance of lodgepole pine (Pinus contorta) was associated with snowshoe hare use within a mixed conifer context, and the only species to increase in abundance with horizontal cover was Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa). Our landscape‐level modeling produced similar patterns in that we observed a positive effect of lodgepole pine and horizontal cover on both occupancy and use by snowshoe hares, but we also observed a positive yet parabolic effect of snow depth on snowshoe hare occupancy. This work is among the first to characterize the multiscale habitat relationships of snowshoe hares across a mixed conifer landscape as well as to map their occupancy and intensity of use. Moreover, our results provide stand‐ and landscape‐level insights that directly relate to management agencies, which aids in conservation efforts of snowshoe hares and their associated predators.  相似文献   

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