bluuebunny/crossref_metadata_2025_split huggingface dataset:
How do crop types influence breeding success in lesser kestrels through prey quality and availability? A modelling approach
Authors: RODRÍGUEZ CARLOS , JOHST KARIN , BUSTAMANTE JAVIER 
Published: March 2006

Summary

In the middle of the 20th century the colonial lesser kestrel Falco naumanni experienced a marked decline in its western palaearctic breeding range. Although this decline has been attributed to changes in land use influencing breeding success through lowering the abundance and quality of prey, a quantification of these effects has not yet been undertaken.
To study how these two key factors influence breeding success, we developed an individual‐based model, which translates the hunting performance of each adult foraging trip into nestling growth and enables the effect of crop types on the breeding success of the lesser kestrel to be quantified. Both the authors’ own field data and published inferential and experimental studies were used to parameterize and validate the growth model.
Model results demonstrated that adult provisioning rates provide very little information on the relation between prey availability and breeding success.
On the other hand, the model indicated that small differences in prey abundance among crop types cause large differences in breeding success, highlighting the importance of crop composition in the vicinity of lesser kestrel colonies.
Mean prey biomass is an even more important influence on breeding success. Our results indicated a minimum mean prey size of 0·6 g, below which colonies become population sinks.
Synthesis and applications. We developed an individual‐based model that simulates the growth in body mass of a lesser kestrel brood as a function of prey abundance and prey size. These two key factors define a parameter space in which the conservation status of breeding colonies can be evaluated. We applied the model to six lesser kestrel breeding colonies with different mean prey size and different agricultural land use influencing prey abundance. Our model suggests that the habitat quality of two of these colonies is sufficient for population persistence, while management actions to increase habitat quality are required in the remaining four colonies. An increase in the availability of prey‐rich habitats such as field margins would achieve this goal without imposing too great a cost on the local farming community.
Assessing the viability of tiger subpopulations in a fragmented landscape
Authors: LINKIE MATTHEW , CHAPRON GUILLAUME , MARTYR DEBORAH J. , HOLDEN JEREMY , LEADER‐WILLIAMS NIGEL 
Published: March 2006

Summary

Conservation managers require accurate and timely information on the occurrence, size and viability of populations, but this is often difficult for cryptic species living at low densities over large areas. This study aimed to provide such information for tigers in the 36 400‐km2 Kerinci Seblat (KS) region, Sumatra, by identifying and assessing subpopulation viability under different management strategies.
Tiger occurrence was mapped within a geographical information system (GIS) using repeat detection–non‐detection surveys to incorporate a function of detection probability into a logistic regression model. The landscape variables that influenced tiger occupancy were then used to construct a spatially explicit habitat model to identify core areas.
The number of tigers within each core area was estimated by calculating the area of different forest types and their respective tiger densities as determined through camera trapping. The viability of each subpopulation was then assessed under different management scenarios using a population viability analysis (PVA).
Tiger occurrence was negatively correlated with distance to public roads. Four core tiger areas were identified, all predominantly located within KS National Park, estimated to support subpopulations of 21, 105, 16 and three adult tigers, respectively. PVA showed that the three larger subpopulations could be demographically viable if well protected. However, if poaching removed ≥ 3 tigers per year, then only the largest subpopulation would not reach extinction within 50 years. Connectivity to this large subpopulation would ensure survival of the smaller subpopulations, through providing a source of tigers to offset poaching losses.
Synthesis and applications. Our key management recommendations for tigers in the Kerinci Seblat region of Sumatra stress the importance of maintaining connectivity between the smaller areas and the larger area, and minimizing poaching within these smaller areas. More widely, our research has shown the feasibility of using detection–non‐detection surveys combined with spatial modelling to provide timely information for conservation management.
Floodplain restoration by reinforcing hydrological connectivity: expected effects on aquatic mollusc communities
Authors: RECKENDORFER WALTER , BARANYI CHRISTIAN , FUNK ANDREA , SCHIEMER FRITZ 
Published: March 2006

Summary

One of the main targets of river–floodplain restoration is the reconnection of former side channels. While there is information about the overall impact of such measures, far less is known about specific species’ response patterns to hydrological connectivity.
The present study examined the composition of aquatic mollusc communities based on the performance of individual species with respect to hydrological connectivity in the Donau‐Auen National Park, Austria. Species’ traits were used to make generalizations about community responses to hydrological changes.
We introduced a connectivity parameter (Cd, expressed in days year−1) that could easily be derived from the river hydrograph and altitude of the inflow areas. This parameter integrated several key features of floodplain waterbodies and reflected the cause–effect chain of restoration schemes, thus allowing the outcome of restoration measures to be quantitatively predicted. Endangered rheophilic mollusc species reached higher frequencies as connectivity increased; for most eurytopic molluscs, however, increased connectivity reduced abundance.
With respect to species’ traits, the proportion of large gastropods declined continuously with increasing Cd, whereas the percentage of gastropods with globolose shells and the relative number of strongly calcified (thick‐shelled) individuals both increased. Species dominating in isolated sites were characterized by a higher resistance to desiccation, a food preference for higher plants and a preference for less shaded habitats. They matured later and typically had more offspring than rheophilic species.
Species number peaked at connectivity (Cd) values of about 1 month year−1. Isolated and lotic habitats hosted significantly fewer mollusc species. Species turnover was highest when Cd was between 0 days and 2 months.
Synthesis and applications. Empirical models based on a connectivity parameter can be used to predict the consequences of restoration measures on the aquatic mollusc community in the Donau‐Auen National Park. The analysis of species’ traits also allows general prognoses for other river–floodplain systems. Furthermore, initial results based on other taxa indicate a broad applicability of the parameter. The methodology thus provides both an urgently needed and a practical tool for predicting the impact and success of restoration schemes.
Effects of density and floral morph on pollen flow and seed reproduction of an endangered heterostylous herb,Primula sieboldii
Authors: ISHIHAMA F. , UENO S. , TSUMURA Y. , WASHITANI I. 
Published: March 2006

SummaryWe assessed the effects of population density and the spatial arrangement of genetically compatible mates on the seed set and pollen flow of a heterostylous, bumblebee‐pollinated perennial,Primula sieboldiiE. Morren (Primulaceae), by using an experimental population under natural pollination conditions.We also examined the intermorph differences in the pollen dispersal distance and the frequency of self‐ and intramorph fertilization.Seed set was significantly correlated with the number of opposite‐morph flowers within 2 m in short‐styled genets, and within 3 m in long‐styled genets.Mean pollen dispersal distance within the experimental population was 5.4 m, which was slightly shorter than that in a low‐density population measured in a previous study (7.2 m).The proportions of seedlings sired by the same morph or selfed were 10.2% and 3.0%, respectively, in long‐styled mothers, compared with 1.9% and 0.0% among short‐styled mothers. However, these differences were not statistically significant and no marked differences in pollen dispersal distances were observed between the two morphs.Our results suggest that the presence of opposite‐morph genets within several metres is essential for success of seed reproduction inP. sieboldii, irrespective of population density, and that stochastic deviation of the morph ratio in small populations is therefore likely to cause considerable reduction in seed set.
Ecological correlates of range structure in rare and scarce British plants
Authors: POCOCK MICHAEL J. O. , HARTLEY STEPHEN , TELFER MARK G. , PRESTON CHRISTOPHER D. , KUNIN WILLIAM E. 
Published: March 2006

SummaryThe distribution patterns of 391 rare and scarce British plants (species recorded in 100 or fewer 10 × 10 km squares) were characterized by their distributional area (area of occupancy at 1‐km scale: AOO1) and levels of aggregation (as reflected in fractal dimensions measured across two scales:D1−10andD10−100).Eighteen plant traits were tested for relationships to AOO, and to fractal dimension while controlling for AOO. These included both directly heritable traits (e.g. life‐form) and emergent properties that are, at most, indirectly heritable (e.g. typical local density). The latter set included an index of net distributional change and an index of range dynamism.Only two traits, habitat preference and local abundance, were significantly related to AOO1, but about half were associated with fractal dimension.Relatively aggregated fine‐scale distributions (highD1−10) were related to high local abundance, lack of specialized, long‐distance dispersal mechanisms, habitat preference and an increasing range size with relatively few local extinctions (i.e. a positive index of change with low dynamism).Relatively aggregated coarse‐scale distributions (highD10−100) were related to the use of insect pollinators, obligate outcrossing, habitat preference and relatively stable ranges (low dynamism).Multivariate analyses of subsets of conceptually related variables showed that few variables interacted to affect distributional variables.A highly significant negative relationship between dynamism and fractal dimension appears to be driven primarily by high rates of local extinction, leading to relatively scattered, diffuse range structures. Furthermore, it suggests that recent population trends may be inferred from snapshots of contemporary distribution patterns.The role and interpretation of phylogenetically informed analyses in studies such as this are debatable. However, we found similar relationships in both phylogenetically informed and conventional analyses for all variables except pollination vector (a strongly conserved trait).The spatial pattern of plant species distributions is associated with a range of ecological traits, particularly those describing past changes in distribution. The analysis of distribution patterns therefore has the potential to inform future conservation effort.
Biological flora of the British Isles: Cakile maritima Scop.
Authors: DAVY A. J. , SCOTT R. , CORDAZZO C. V. 
Published: March 2006

Summary
This account reviews information on all aspects of the biology of Cakile maritima that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history and conservation.
Cakile maritima (sea rocket) is a succulent, annual species that is confined to maritime strandlines on sand or shingle, and associated foredunes. British material is ssp. integrifolia (= ssp. maritima), found around the Atlantic and Mediterranean coasts of Europe. Cakile maritima shows considerable variation, within and between subspecies, especially in fruit morphology and leaf shape. A very closely related species, Cakile edentula, is native to the east coast of North America. Both species have been introduced to Pacific North America and Australia.
Populations of C. maritima tend be ephemeral and shifting, depending on dispersal by tides and wind. The fruits are 2‐segmented: the distal segments are readily detached and can float considerable distances in seawater; the proximal segments tend to shed their seed while attached to the maternal plant. Seeds require cold stratification and do not germinate at high salinity, or usually while retained in intact fruit segments. There is often a flush of germination in strandlines left by early season, equinoctial spring tides. Cakile maritima shows great phenotypic plasticity of form and reproductive output. Work on C. edentula suggests that abundance is regulated by a combination of density‐dependent and density‐independent processes. Landward dispersal of seeds from strandline populations may subsidise foredune populations, which themselves experience severe mortality from predators.
Cakile maritima is tolerant of salt spray and transient seawater inundation. Although beach and dune sand is a meagre source of macronutrients, C. maritima shows large growth responses to nitrogen addition and can exploit local nitrogen enrichment associated with mineralisation of organic detritus washed up on the strandline. Growth is stimulated by burial with blown sand and plants sometimes form the nuclei of early successional foredunes. The tissues are rich in glucosinolates; these may be responsible for the limited ranges of herbivores and fungal pathogens, and the absence of mycorrhiza.
Parallelism in gene transcription among sympatric lake whitefish (Coregonus clupeaformisMitchill) ecotypes
Authors: DEROME N. , DUCHESNE P. , BERNATCHEZ L. 
Published: March 2006

AbstractWe tested the hypothesis that phenotypic parallelism between dwarf and normal whitefish ecotypes (Coregonus clupeaformis,Salmonidae) is accompanied by parallelism in gene transcription. The most striking phenotypic differences between these forms implied energetic metabolism and swimming activity. Therefore, we predicted that genes showing parallel expression should mainly belong to functional groups associated with these phenotypes. Transcriptome profiles were obtained from white muscle by using a 3557 cDNA gene microarray developed for the Atlantic salmon (Salmo salar). A total of 1181 genes expressed in both lake populations hybridized on the array. Significant differential expression between ecotypes was detected for 134 (11.3%) and 195 (16.5%) gene clones in Cliff Lake and Indian Pond, respectively. Fifty‐one genes (4.3%) showed parallel differential expression between lakes, among which 35 were expressed in opposite directions. Sixteen genes (1.35%) showed true parallelism of transcription, which mainly belonged to energetic metabolism and regulation of muscle contraction functional groups. Variance in expression was significantly reduced for these genes compared to those not showing directionality in parallelism of expression. Candidate genes associated with parallelism in swimming activity and energetic metabolism based on their level and variance in expression were identified. These results add to the growing evidence that parallel phenotypic evolution also involves parallelism at both the genotypic and regulatory level, which may at least partly be associated with genetic constraints. It also provides further evidence for the determinant role of divergent natural selection in driving phenotypic divergence, and perhaps reproductive isolation, in the adaptive radiation of lake whitefish. This study adds to a nascent field employing microarrays as powerful tools for investigating the evolutionary processes of adaptive divergence among natural populations.
Population genetic structure and demographic history of the endemic Formosan lesser horseshoe bat (Rhinolophus monoceros)
Authors: CHEN SHIANG‐FAN , ROSSITER STEPHEN J. , FAULKES CHRISTOPHER G. , JONES GARETH 
Published: March 2006

AbstractIntraspecific phylogenies can provide useful insights into how populations have been shaped by historical and contemporary processes. Taiwan formed around 5 million years ago from tectonic uplift, and has been connected to mainland Asia several times since its emergence. A central mountain range runs north to south, bisecting the island, and potentially impedes gene flow along an east–west axis. The Formosan lesser horseshoe bat (Rhinolophus monoceros) is endemic to Taiwan, where it is found mainly at low altitude. To determine the population structure and the demographic and colonization history of this species, we examined variation in the mitochondrial DNA control region in 203 bats sampled at 26 sites. We found very high haplotype and nucleotide diversity, which decreased from the centre to the south and north. Population differentiation followed a pattern of isolation by distance, though most regional genetic variance was attributable to differences between the relatively isolated southern population and those from other regions. A haplotype network was consistent with these findings and also suggested a southward colonization, followed by subsequent secondary contact between the south and other regions. Mismatch distributions were used to infer a past population expansion predating the last glacial maximum, and a neighbour‐joining tree showed thatR. monocerosformed a monophyletic grouping with respect to its sister taxa. Taken together, our results suggest that this taxon arose from a single period of colonization, and that demographic growth followed in the late Pleistocene. Current genetic structure reflects limited gene flow, probably coupled with stepwise colonization in the past. We consider explanations for the persistence of the species through multiple glacial maxima.
Mycobacterium tuberculosis malate synthase is a laminin‐binding adhesin
Authors: Kinhikar Arvind G. , Vargas Diana , Li Hualin , Mahaffey Spencer B. , Hinds Laura , Belisle John T. , Laal Suman 
Published: March 2006

Summary Mycobacterium tuberculosis (M. tb) uses the glyoxalate bypass for intracellular survival in vivo. These studies provide evidence that the M. tb malate synthase (MS) has adapted to function as an adhesin which binds to laminin and fibronectin. This binding is achieved via the unique C‐terminal region of the M. tb MS. The ability to function as an adhesin necessitates extracellular localization. We provide evidence that despite the absence of a Sec‐translocation signal sequence the M. tb MS is secreted/excreted, and is anchored on the cell wall by an undefined mechanism. The MS of Mycobacterium smegmatis is cytoplasmic but the M. tb MS expressed in M. smegmatis localizes to the cell wall and enhances the adherence of the bacteria to lung epithelial A549 cells. Antibodies to the C‐terminal laminin/fibronectin‐binding domain interfere with the binding of the M. tb MS to laminin and fibronectin and reduce the adherence of M. tb to A549 cells. Coupled to the earlier evidence of in vivo expression of M. tb MS during active but not latent infection in humans, these studies show that a housekeeping enzyme of M. tb contributes to its armamentarium of virulence promoting factors.
Dihydroxyacetone detoxification in Saccharomyces cerevisiae involves formaldehyde dissimilation
Authors: Molin Mikael , Blomberg Anders 
Published: March 2006

SummaryTo investigate Saccharomyces cerevisiae physiology during growth on the conditionally toxic triose dihydroxyacetone (DHA), protein expression was studied in strains overexpressing either of the two dihydroxyacetone kinase isogenes, DAK1 or DAK2, that grow well utilizing DHA as a carbon and energy source. DHA metabolism was found mostly similar to ethanol utilization, involving a strong component of glucose derepression, but also involved DHA‐specific regulatory changes. A specific and strong (10‐ to 30‐fold induction of formaldehyde dehydrogenase, Fdhlp, indicated activation of the formaldehyde dissimilation pathway in DHA medium. The importance of this pathway was further supported by impaired adaptation to DHA growth and DHA survival in a glutathione‐dependent formaldehyde dehydrogenase (SFA1) deletion mutant. Glutathione synthase (GSH1) deletion led to decreased DHA survival in agreement with the glutathione cofactor requirement for the SFA1‐encoded activity. DHA toxicity did, however, not solely appear related to formaldehyde accumulation, because SFA1 overexpression only enhanced formaldehyde but not DHA tolerance. In further agreement with a low DHA‐to‐formaldehyde flux, GSH supplements in the low µM range also fully suppressed the DHA sensitivity of a gsh1Δ strain. Under growth reduction on high (100 mM) DHA medium we report increased levels of advanced glycation end‐product (AGE) formation on total protein. Under these high‐DHA conditions expression of several stress‐related proteins, e.g. a heat‐shock protein (Hsp104p) and the oxidative stress indicator, alkyl hydroperoxide reductase (Ahp1p) was also found induced. However, hallmark determinants of oxidative stress tolerance (e.g. YAP1, SKN7, HYR1/GPX3 and SOD2) were redundant for DHA tolerance, thus indicating mechanisms of DHA toxicity largely independent of central oxidative stress defence mechanisms. We conclude that mechanisms for DHA growth and detoxification appear complex and that the evolutionary strive to minimize detrimental effects of this intracellular metabolite links to both formaldehyde and glutathione metabolism.
Analysis of FimX, a phosphodiesterase that governs twitching motility in Pseudomonas aeruginosa
Authors: Kazmierczak Barbara I. , Lebron Maria B. , Murray Thomas S. 
Published: March 2006

SummaryType IV pili (Tfp) are polar surface structures of Pseudomonas aeruginosa required for twitching motility, biofilm formation and adherence. One protein required for the assembly of tfp is FimX, which possesses both GGDEF and EAL domains characteristic of diguanylate cyclases and phosphodiesterases respectively. In this work we demonstrate that FimX has phosphodiesterase activity towards bis‐(3′‐5′)‐cyclic dimeric guanosine monophosphate (c‐di‐GMP), but does not show diguanylate cyclase activity. Instead, the imperfect GGDEF domain of FimX likely serves to activate phosphodiesterase activity when bound to GTP, as has recently been described for the Caulobacter crescentus composite GGDEF‐EAL protein, CC3396. Bacteria expressing FimX in which either the GGDEF or EAL domain is deleted or mutated have phenotypes indistinguishable from a ΔfimX strain, demonstrating the importance of both domains to function. Previous work has shown that FimX localizes to the bacterial pole. In this work we show that restriction of FimX to a single pole requires intact GGDEF and EAL domains. Deletion of the amino‐terminal REC domain of FimX, which contains a putative polar localization signal, results in a protein that still supports intermediate levels of pilus assembly and function. RFP–FimXΔREC, unlike RFP–FimX, is no longer localized to the bacterial pole, while transmission electron microscopy shows that surface pili can originate from non‐polar sites in this mutant. Although ΔfimX mutants show limited in vitro cytotoxicity, they are as virulent as the wild‐type strain in a murine model of acute pneumonia.