bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anti‐idiotype antibody induced cellular immunity in mice transgenic for human carcinoembryonic antigen
Authors: Saha Asim , Chatterjee Sunil K. , Foon Kenneth A. , Bhattacharya‐Chatterjee Malaya 
Published: May 2006

SummaryIn the present study, we have analysed the detailed cellular immune mechanisms involved in tumour rejection in carcinoembryonic antigen (CEA) transgenic mice after immunization with dendritic cells (DC) pulsed with an anti‐idiotype (Id) antibody, 3H1, which mimics CEA. 3H1‐pulsed DC vaccinations resulted in induction of CEA specific cytotoxic T lymphocyte (CTL) responses in vitro and the rejection of CEA‐transfected MC‐38 murine colon carcinoma cells, C15, in vivo (Saha et al.,Cancer Res 2004; 64: 4995–5003). These CTL mediated major histocompatibility complex (MHC) class I‐restricted tumour cell lysis, production of interferon‐γ (IFN‐γ) and tumour necrosis factor‐α (TNF‐α), and expression of Fas ligand (FasL) and TNF‐related apoptosis‐inducing ligand (TRAIL) in response to C15 cells. CTL used perforin‐, FasL‐, and TRAIL‐mediated death pathways to lyse C15 cells, although perforin‐mediated killing was the predominant lytic mechanism in vitro. The cytokines IFN‐γ and TNF‐α synergistically enhanced surface expression of Fas, TRAIL receptor, MHC class I and class II on C15 cells that increased the sensitivity of tumour cells to CTL lysis. CTL activity generated in 3H1‐pulsed DC immunized mice was directed against an epitope defined by the idio‐peptide LCD‐2, derived from 3H1. In vivo lymphocyte depletion experiments demonstrated that induction of CTL response and antitumour immunity was dependent on both CD4+ and CD8+ T cells. The analysis of splenocytes of immunized mice that had rejected C15 tumour growth revealed up‐regulated surface expression of memory phenotype Ly‐6C and CD44 on both CD4+ and CD8+ T cells. The adoptive transfer experiments also suggested the role of both CD4+ and CD8+ T cells in this model system. Furthermore, mice that had rejected C15 tumour growth, developed tumour‐specific immunological memory.
Alleviation of pre‐exposure of mouse brain with low‐dose 12C6+ ion or 60Co gamma‐ray on male reproductive endocrine damages induced by subsequent high‐dose irradiation
Authors: Zhang Hong , Liu Bing , Zhou Qingming , Zhou Guangming , Yuan Zhigang , Li Wenjian , Duan Xin , Min Fengling , Xie Yi , Li Xiaoda 
Published: May 2006

SummaryIrradiation has been widely reported to damage organisms by attacking on proteins, nucleic acid and lipids in cells. However, radiation hormesis after low‐dose irradiation has become the focus of research in radiobiology in recent years. To investigate the effects of pre‐exposure of mouse brain with low‐dose 12C6+ ion or 60Co gamma (γ)‐ray on male reproductive endocrine capacity induced by subsequent high‐dose irradiation, the brains of the B6C3F1 hybrid strain male mice were irradiated with 0.05 Gy of 12C6+ ion or 60Co γ‐ray as the pre‐exposure dose, and were then irradiated with 2 Gy as challenging irradiation dose at 4 h after pre‐exposure. Serum pituitary gonadotropin hormones, follicle‐stimulating hormone (FSH) and luteinizing hormone (LH), testosterone, testis weight, sperm count and shape were measured on the 35th day after irradiation. The results showed that there was a significant reduction in the levels of serum FSH, LH, testosterone, testis weight and sperm count, and a significant increase in sperm abnormalities by irradiation of the mouse brain with 2 Gy of 12C6+ ion or 60Co γ‐ray. Moreover, the effects were more obvious in the group irradiated by 12C6+ ion than in that irradiated by 60Co γ‐ray. Pre‐exposure with low‐dose 12C6+ ion or 60Co γ‐ray significantly alleviated the harmful effects induced by a subsequent high‐dose irradiation.
Relationship between seminal ascorbic acid and sperm DNA integrity in infertile men
Authors: Song Gyun Jee , Norkus Edward P. , Lewis Vivian 
Published: May 2006

SummaryAscorbic acid has recently been reported to protect sperm DNA from the damage induced by exogenous oxidative stress in vitro. But, there is no report on seminal ascorbic acid and sperm DNA fragmentation in infertile men. In this study, we asked whether sperm DNA damage correlates with seminal ascorbic acid levels. Sperm DNA fragmentation index (DFI) was analysed in 75 men by flow cytometry after acridine orange staining. We also measured the levels of seminal plasma ascorbic acid and total antioxidant capacity. Abnormal sperm DNA integrity (DFI ≥ 30%) was observed in 12% of the patients with normal semen parameters and in 52% of the patients with abnormal semen parameters. There were significant correlations between the level of DFI and conventional semen parameters including sperm count, motility and morphology (r = −0.29, −0.55 and −0.53 respectively; p < 0.05). Seminal ascorbic acid level was significantly lower in the patients with leucospermia than the patient with normal semen parameters. Interestingly, a significantly greater percentage of men with abnormal DFI were observed in the patients with low levels of seminal ascorbic acid compared with those with normal or high levels of ascorbic acid (59% vs. 33%, p < 0.05). Men with insufficient seminal ascorbic acid frequently have sperm DNA damage.
Aerial photographs as a tool for assessing the regional dynamics of the invasive plant speciesHeracleum mantegazzianum
Authors: MÜLLEROVÁ JANA , PYŠEK PETR , JAROŠÍK VOJTĚCH , PERGL JAN 
Published: May 2006

SummaryThe initiation of an invasion event is rarely dated in studies of alien plants. Data from aerial photographs documenting the invasion from the outset facilitate the quantification of the rate of spread, allowing researchers to analyse species’ population dynamics and providing a basis for management.For 10 sites invaded byHeracleum mantegazzianumin the Slavkovský les, Czech Republic, aerial photographs from 11 sampling dates between 1947 (before invasion started) and 2000 were analysed. The area covered by the invader was measured digitally in a 60‐ha section of landscape, and information obtained on invaded habitats, year of invasion, flowering intensity and structure of patches. Invaded area was regressed on residence time (time since the beginning of invasion) and regression slopes were used to measure the rate of spread. Data were analysed byancova, multiple regression and path analysis.Pastures and fields contributed 84·7% toHeracleumtotal cover, forest and scrub 13·7% and human settlements 1·6% at the later stage of invasion. The direct effect of the rate of invasion on invaded area (0·82) was greater than that of residence time (0·22), but the total effect (direct and indirect) of residence time was only slightly less (0·79) than that of the rate of invasion (0·82). As invasion proceeded, the populations spread from linear habitats to the surrounding landscape. Mean rate of areal spread was 1261 m2year−1and that of linear spread 10·8 m year−1. Flowering intensity did not exhibit any significant trend over time.Synthesis and applications.The strong effect of the rate of spread on the invaded area indicates that local environmental conditions hardly limit the spread ofHeracleum. The species is easily detectable on aerial photographs taken at flowering and early fruiting times, from June to August. Knowledge gained from aerial photographs allows managers to identify dispersal foci and to focus control efforts on linear landscape structures with developing populations. Knowledge of the rate of spread and habitat vulnerability to invasion facilitates the identification of areas at highest risk of immediate invasion.
Restoring ecological function in temperate grassy woodlands: manipulating soil nutrients, exotic annuals and native perennial grasses through carbon supplements and spring burns
Authors: PROBER SUZANNE M. , THIELE KEVIN R. , LUNT IAN D. , KOEN T. B. 
Published: May 2006

Summary
Ecological invasions are often associated with persistent changes to underlying ecological processes. Restoration of invaded communities is dependent on manipulation of these processes to favour the target species composition and impart resistance to further invasion. We applied these principles to extensively degraded grassy woodlands in temperate agricultural regions of Australia, where widespread invasion by mediterranean annuals is related to altered ecological processes such as soil nutrient cycling.
We investigated carbon supplementation and spring burns, in association with re‐establishment of native perennial grasses, as potential management tools for manipulating nitrogen cycling, soil seed banks and establishment conditions in degraded woodland understoreys. Through these mechanisms we aimed to enhance native cover and increase resistance to invasion by exotic annuals.
In two contrasting degraded remnants, repeated sucrose applications temporarily reduced soil nitrate to inferred pre‐European levels, which dramatically reduced growth of exotic annuals and enhanced native perennial abundance. Repeated spring burns did not reduce soil nitrate but reduced exotic annual grasses through effects on soil seed banks and/or establishment conditions.
Spring burns and carbon supplements both significantly enhanced establishment of Themeda australis, a dominant tussock grass prior to European settlement. Combinations of T. australis seed addition and either spring burning or carbon supplements enhanced native plant abundance more effectively than treatments without seed addition.
Within 18 months of their establishment, T. australis seedlings significantly reduced soil nitrate in some treatments, providing a preliminary indication that re‐establishment of a dense sward of this species may restore ecosystem function to a low‐nitrate state that favours native perennials over exotic annuals.
Synthesis and applications. Ecological restoration can be viewed as targeted intervention in species–environment interactions, whereby ecological conditions are manipulated to enhance establishment or vigour of key species, and these species in turn help restore ecological processes that favour the target species composition. In grassy ecosystems re‐establishing a perennial sward of appropriate native tussock grasses may be critical for restoring pre‐disturbance nitrogen cycles and improving resistance to invasion by exotic annuals. Carbon supplements and spring burns facilitate this process through complementary mechanisms.
Artificial marine structures facilitate the spread of a non‐indigenous green alga, Codium fragile ssp. tomentosoides, in the north Adriatic Sea
Authors: BULLERI FABIO , AIROLDI LAURA 
Published: May 2006

Summary
Artificial structures have become ubiquitous features of coastal landscapes. Although they provide novel habitats for the colonization of marine organisms, their role in facilitating biological invasions has been largely unexplored.
We investigated the distribution and dynamics of the introduced green alga, Codium fragile ssp. tomentosoides, at a variety of spatial scales on breakwaters in the north Adriatic Sea, and analysed experimentally the mechanisms underlying its establishment. We assessed the provision of sheltered habitats by breakwaters, the role of disturbance (e.g. from recreational harvesting and storms) acting at different times of the year, and the interactions between Codium and the dominant native space‐occupier, the mussel Mytilus galloprovincialis.
Codium fragile ssp. tomentosoides has established viable populations on artificial structures along the shores investigated. The density, cover and size (length, branching and weight) of annual erect thalli of Codium was enhanced in sheltered conditions, resulting in the monopolization of landward low‐shore habitats of breakwaters.
On the landward sides of breakwaters, disturbance enhanced recruitment of Codium. The time when bare space was provided within mussels beds was crucial. Removal of mussels in April or January did not affect the recruitment of Codium, whereas harvest in August, shortly before Codium gamete release, doubled its success. On the seaward sides of breakwaters, the effects of disturbance were more complex because mussels both inhibited recruitment of Codium and provided shelter from wave action to adult thalli.
Synthesis and applications. Artificial structures can provide suitable habitats for non‐indigenous marine species and function as corridors for their expansion. Physical (wave exposure) and biotic (resident assemblages) features of artificial habitats can be important determinants of their susceptibility to biological invasions. Alternative options in the design of artificial structures and effective management of native assemblages could minimize their role in biological invasions. In particular, increased water motion and retention of space by mussels in spring–summer would be effective in reducing the ability of C. fragile ssp. tomentosoides to persist on the breakwaters investigated in this study.
Profiting from prior information in Bayesian analyses of ecological data
Authors: McCARTHY MICHAEL A. , MASTERS PIP 
Published: May 2006

SummaryMost ecological studies include prior information only implicitly, usually in their design or the discussion of results. In this study, two examples demonstrate that using Bayesian statistics to incorporate basic ecological principles and prior data can be very cost‐effective for increasing confidence in ecological research.The first example is based on examining the effects of an experimental manipulation of the habitat of mulgaraDasycercus cristicauda, a marsupial of inland Australia. The second example is based on observational mark–recapture data to estimate the annual survival of the European dipperCinclus cinclus, a passerine in France.In the mulgara example, the prior information obtained from an observational study increased confidence that there was an adverse effect of experimental habitat manipulation on the species. The results suggested that the capture rate of mulgara was reduced to approximately one‐quarter by reduction of vegetation cover.In the European dipper example, prior information based on the body mass of the species and estimates of annual survival of other European passerines was shown to be worth between 1 and 5 years of mark–recapture field data.Synthesis and applications. Body mass can be used to predict annual survival of European passerines and other animals. Results of observational studies can provide prior information in experimental studies of impacts of habitat change. By using Bayesian methods, such prior information, if represented in a coherent and logical way, can be cost‐effective for adding certainty to ecological studies.
Evaluating the impact of a biological control agent Carmenta mimosa on the woody wetland weed Mimosa pigra in Australia
Authors: PAYNTER QUENTIN 
Published: May 2006

Summary
Evaluation of the success of biological control agents is essential to improve the efficiency and safety of future programmes. This study assessed the impact of Carmenta mimosa, a stem‐mining moth, introduced into northern Australia as a biological control agent of mimosa Mimosa pigra. Litter fall, seed banks, vegetation cover, density and age structure of mimosa stands were compared using data collected at nine sites where Carmenta mimosa was present and eight sites where it was initially absent.
Mimosa seed rain was negatively correlated with Carmenta mimosa damage and declined by more than 90% at the highest Carmenta mimosa densities. Seed banks also declined with Carmenta mimosa damage.
Percentage cover of competing vegetation was significantly higher under stands defoliated by Carmenta mimosa and this inhibited mimosa seedling establishment and apparently increased the susceptibility of mimosa to fire, by increasing fuel loads beneath stands.
Four of the eight stands where Carmenta mimosa was absent expanded and none contracted. In contrast, none of the nine stands where Carmenta mimosa was present expanded and three contracted. Analysis of the age structure of mimosa stands indicated that contracting stands were typified by an absence of seedling regeneration.
In contrast to previous studies, no impact could be attributed to the flower feeder Coelocephalapion pigrae or to the stem‐mining moth Neurostrota gunniella, whilst the bruchid Acanthoscelides puniceus consumed up to only c. 10% of seed. However, it is argued that, while these agents are unlikely to suppress dense mimosa thickets, they may reduce the rate mimosa can expand.
Synthesis and applications. By preventing stand regeneration, Carmenta mimosa is predicted to cause widespread reductions in mimosa populations and should therefore be redistributed to areas of mimosa where it is absent. Differences between the age structures of stands with Carmenta mimosa present may highlight how biological control could succeed for a suite of woody legume weeds with long‐lived seed banks.
Parasites and the island syndrome: the colonization of the western Mediterranean islands by Heligmosomoides polygyrus (Dujardin, 1845)
Authors: Nieberding C. , Morand S. , Libois R. , Michaux J. R. 
Published: May 2006

AbstractAim  Populations of free‐living vertebrates on islands frequently differ from their mainland counterparts by a series of changes in morphometric, life‐history, behavioural, physiological and genetic traits, collectively referred to as the ‘island syndrome’. It is not known, however, whether the ‘island syndrome’ also affects parasitic organisms. The present study establishes the colonization pattern of the Mediterranean islands by the nematode Heligmosomoides polygyrus, a direct and specific parasite of rodent hosts of the Apodemus genus, and evaluates the effects of island colonization by this species on two components of the island syndrome: the loss of genetic diversity and the enlargement of the ecological niche.Location  Heligmosomoides polygyrus was sampled on seven western Mediterranean islands − Corsica, Crete, Elba, Majorca, Minorca, Sardinia and Sicily − as well as in 20 continental locations covering the Mediterranean basin.Methods  The mitochondrial cytochrome b gene (690 base pairs) was sequenced in 166 adult H. polygyrus individuals sampled in the 27 continental and island locations. Phylogenetic reconstructions in distance, parsimony, maximum likelihood and Bayesian posterior probabilities were carried out on the whole cytochrome b gene data set. The levels of nucleotide, haplotype and genetic divergence (Kimura two‐parameter distance estimator) diversities were estimated in each island population and in the various continental lineages.Results  Phylogenetic reconstructions show that the mainland origins of H. polygyrus were continental Spain for the Balearic Islands (Majorca, Minorca), northern Italy for the Tyrrhenian Islands (Corsica, Sardinia, Elba), southern Italy for Sicily, and the Balkan region for Crete. A comparison of island H. polygyrus populations with their mainland source populations revealed two characteristic components of the island syndrome in this parasite. First, island H. polygyrus populations display a significant loss of genetic diversity, which is related (r2 = 0.73) to the distance separating the island from the mainland source region. Second, H. polygyrus exhibits a niche enlargement following insularization. Indeed, H. polygyrus in Corsica is present in both A. sylvaticus and Mus musculus domesticus, while mainland H. polygyrus populations are present exclusively in Apodemus hosts.Main conclusions  Our results show that H. polygyrus has undergone a loss of genetic diversity and a niche (host) enlargement following colonization of the western Mediterranean islands. To our knowledge, this study provides the first evidence for components of the ‘island syndrome’ in a parasitic nematode species.
Ecological traits influence the current distribution and range of an island endemic bird
Authors: Illera Juan Carlos , Díaz Mario , Nogales Manuel 
Published: May 2006

AbstractAim The aim of this paper is to investigate the causes of the current restricted distribution of a narrow‐range endemic bird species, the Canary Islands stonechat,Saxicola dacotiae.Location Eastern islands of the Canary Islands archipelago.Methods We compared climatic patterns (temperature and rainfall), habitat and microhabitat structure, food availability during a full annual cycle, and the abundance of native avian competitors and predators inside and outside the species’ range. Three study areas, located in similar habitats on nearby islands, were studied: northern Fuerteventura, close to the northern border of the species’ range; southern Lanzarote, 22 km from the nearest site occupied by stonechats; and the Lobos islet, 10 km from the nearest occupied site and 2 km from the coast of Fuerteventura.Results The cover of suitable habitats (slopes with high cover of large shrubs, stony fields and ravines) and microhabitats (shrubs and boulders) and the abundance of arthropods during the breeding period of Canary Islands stonechats were lower outside than inside the species’ range. Temperature, rainfall and the abundance of competitors and predators inside and outside the species’ range did not differ significantly.Main conclusions Ecological requirements explaining the distribution of the Canary Islands stonechat within its range seem to be the main factor hindering its settlement on nearby islands. Geological and palaeoclimatic processes, as well as past and current human impact, could also have constrained the distribution of this narrow‐range endemic bird species.
Post‐fire recovery of Mediterranean ground ant communities follows vegetation and dryness gradients
Authors: Arnan Xavier , Rodrigo Anselm , Retana Javier 
Published: May 2006

AbstractAim In the Mediterranean Basin, the main forest communities vary in their ability to recover after fire. In this study we analyse the effects of fire on ant communities occurring in various vegetation types distributed along a geographical gradient in the western Mediterranean region.Location The study was carried out in burned and unburned habitats of 22 sites corresponding to eight vegetation types distributed along a gradient of dryness throughout Catalonia (north‐east Spain).Methods We placed five pairs of plots (one plot located in the burned area and the second one placed in the unburned margin) per site. We compared ant communities in these unburned and burned plot types 8 years after fire using pitfall traps. Traps were set out in mid‐May and mid‐July. We analysed the structure and composition of ant communities in the burned and unburned areas of these vegetation types usinganovatests, correspondence analysis (CA) and linear regression.Results The resilience of ant communities varies with vegetation type. Ant communities in forests with high resilience also recover rapidly after fire, while those in forests that do not recover after fire show the lowest resilience. Species richness does not depend on burning or vegetation type. The resilience of these Mediterranean ant communities to fire is related to the environmental characteristics of the region where they live. Accordingly, differences between burned and unburned habitats are smaller for ant communities in areas with higher water deficit in summer than for those in moister ones.Main conclusions The structure and composition of ant communities after fire depends on the level of direct mortality caused by the fire. It affects ant species differently, as determined by the habitats used for nesting and foraging. The reestablishment of vegetation cover depends on forest composition before the fire. As vegetation cover determines resource and microhabitat availability and competitive relationships among species, forest composition before the fire also affects post‐fire recovery of ant communities to the medium‐term. Finally, ant communities living in drier areas recover more quickly after fire than those living in moister ones. This pattern might be because in areas with higher water deficit there are more species characteristic of open environments, which are habitats similar to those generated after fire.