bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implications of closed ecosystem conservation management: the decline of Rothschild’s giraffe (Giraffa camelopardalis rothschildi) in Lake Nakuru National Park, Kenya
Authors: Brenneman Rick A. , Bagine Richard K. , Brown David M. , Ndetei Robert , Louis Edward E. 
Published: August 2009

AbstractGiraffe were historically free‐ranging across most of sub‐Saharan Africa but are now most often confined to national parks, conservation areas, or private ranches. Five viable populations of Rothschild’s giraffe (Giraffa camelopardalis rothschildi) remain in protected areas in Kenya and Uganda. The viable population in Uganda is Murchison Falls National Park and the four populations in Kenya are Lake Nakuru National Park (LNNP), Ruma National Park, Giraffe Manor, and Mwea Natural Reserve. The Kenya Wildlife Service queried a rapid decline in LNNP giraffe numbers falling from 153 individuals (1995) to 62 individuals (2002) and the failure of that population to recruit young in those years. Significantly reduced browse options, inbreeding depression and preferential lion predation were considered as potential reasons for this trend. Population genetic parameter estimates derived from multilocus genotype analyses suggest that the LNNP population was in good genetic health with respect to the likelihood of inbreeding depression. The population decline coincided with the drought attributed to the 1994 El Niño. Possible dietary complications from highly concentrated tannin levels because of forced over consumption of the park’s declining acacia trees may have compromised young giraffe, making them easy and opportunistic prey for the park’s lion population.
Composition and distribution of vascular epiphytes in a tropical semideciduous forest, Ghana
Authors: Addo‐Fordjour Patrick , Anning Alexander Kofi , Addo Mathew Glover , Osei Margaret Frimpomaa 
Published: August 2009

AbstractThe composition and distribution of vascular epiphytes were studied in two 1‐ha plots in the KNUST Botanic garden, Ghana. One‐hectare plot each was randomly set up in secondary and cultivated forests for the identification and enumeration of trees and shrubs (≥10 cm dbh), and epiphytes. Each tree was carefully examined, noting the presence, positions and life‐forms of all epiphytes. Twenty‐nine epiphyte (29) species belonging to fourteen genera and eleven families were identified in the study. These were hosted by 48 tree species and occurred in three life‐forms: hemi‐epiphytes (45%), casual epiphytes (45%) and true epiphytes (10%). The vascular epiphyte species made up 25.7% of all the identified plant species (excluding herbs and climbers) encountered. Host species (P < 0.001), habitat (P = 0.001) and their interaction (P < 0.001) had strong effects on epiphyte composition in the forests. Moraceae was the most dominant family (44.8%), while Nephrolepis undulata J. Sm. and N. biserrata (Sw.) Scott. were the commonest species of epiphytes. In terms of vertical distribution, most epiphytes were located on the trunk, while a few occurred in the canopy.
Invertebrate community structure and ecosystem functioning in European conifer plantation streams
Authors: RIIPINEN MIIRA P. , FLEITUCH TADEUSZ , HLADYZ SALLY , WOODWARD GUY , GILLER PAUL , DOBSON MICHAEL 
Published: August 2009

Summary1. Terrestrial leaf‐litter is the dominant energy input to many headwater streams and consequently the nature of the riparian vegetation can have profound effects on in‐stream processes. The impact of conifer plantations on community structure and ecosystem functioning (litter breakdown) was investigated in field experiments in three countries (Britain, Ireland, Poland), each representing a distinct European ecoregion. Twenty‐six streams were used in the trial: half were bordered with broadleaved and the other half with conifer riparian vegetation.2. In a leaf breakdown study using litter bags, two leaf types (oak and alder) were used to assess the impact of resource quality and two mesh sizes (10 and 0.5 mm aperture) were used to gauge the relative importance of invertebrate detritivores and microbial decomposers respectively. Comparisons were made between vegetation types and among regions; pH varied among individual streams but, unlike many previous studies, it was not confounded with vegetation type, enabling us to isolate the effect of vegetation more effectively.3. Overall, riparian vegetation type did not affect breakdown rates but strong regional differences were observed. There was also a significant interaction between these two variables, but this disappeared after fitting pH as a covariable, demonstrating its importance in determining breakdown rates and raising the possibility that in previous studies the impacts of conifer plantations might have been confounded with pH.4. Shredder species composition differed between vegetation types. Small stoneflies were most strongly associated with conifer streams; broadleaved streams generally had a higher proportion of larger taxa, such as limnephilid caddisflies and gammarid shrimps, although the latter were excluded from sites with low pH. However, breakdown rates were maintained irrespective of shredder community composition, suggesting a high degree of functional redundancy in these communities. Similar processing rates were observed between streams with high numbers of nemourids and those with only a few limnephilids or gammarids, suggesting that density compensation among consumers might stabilise process rates.5. Our results suggest that leaf‐litter breakdown can be an effective proxy for assessing stream ecosystem functioning, as rates differed significantly across spatial scales, from between streams to across regions and responded to an environmental gradient (pH). The litter bag technique can also complement traditional assessment methods by providing valuable information on the composition of consumer guilds, thereby providing an important link between structure and function that is needed to help inform management practices.
‘Value of FSH and inhibin‐B measurements in the diagnosis of azoospermia’– A clinician’s overview
Authors: Adamopoulos D. A. , Koukkou E. G. 
Published: August 2009

SummaryAzoospermia can be either of obstructive ctiology or due to the testis' failure to initiate or maintain spermatogenesis. FSH acts through its receptor at Sertoli cell level and modulates spermatogenesis initiation and maintenance. Inhibin B is a Sertoli cell product expressing the functional capacity of the cell and in an indirect way the state of seminiferous tubule activity. Both FSH and inhibin B differentiate clearly testicular from extra‐testicular pathology of azoospermia while, none of these hormones has been convincingly established as predictory index for the finding of spermatozoa in TESE.
Biogeographical patterns of blood parasite lineage diversity in avian hosts from southern Melanesian islands
Authors: Ishtiaq Farah , Clegg Sonya M. , Phillimore Albert B. , Black Richard A. , Owens Ian P. F. , Sheldon Ben C. 
Published: August 2009

AbstractAim  (1) To describe the species–area relationships among communities of Plasmodium and Haemoproteus parasites in different island populations of the same host genus (Aves: Zosterops). (2) To compare distance–decay relationships (turnover) between parasite communities and those with potential avian and dipteran hosts, which differ with respect to their movement and potential to disperse parasite species over large distances.Location  Two archipelagos in the south‐west Pacific, Vanuatu and New Caledonia (c. 250 km west of Vanuatu) and its Loyalty Islands, with samples collected from a total of 16 islands of varying sizes (328–16,648 km2).Methods  We characterized parasite diversity and distribution via polymerase chain reaction (PCR) from avian (Zosterops) blood samples. Bayesian methods were used to reconstruct the parasite phylogeny. In accordance with recent molecular evidence, we treat distinct mitochondrial DNA lineages as equivalent to species in this study. Path analysis and parasite lineage accumulation curves were used to assess the confounding effect of inadequate sampling on the estimation of parasite richness. Species–area and species–distance relationships were assessed using linear regression: distance–decay relationships were assessed using Mantel tests.Results  Birds and mosquito species and Plasmodium lineages exhibited significant species–area relationships. However, Plasmodium lineages showed the weakest ‘species–area’ relationship; no relationship was found for Haemoproteus lineages. Avian species richness influenced parasite lineage richness more than mosquito species richness did. Within individual avian host species, the species–area relationship of parasites showed differing patterns. Path analysis indicated that sampling effort was unlikely to have a confounding effect on parasite richness. Distance from mainland (isolation effect) showed no effect on parasite richness. Community similarity decayed significantly with distance for avifauna, mosquito fauna and Plasmodium lineages but not for Haemoproteus lineages.Main conclusions  Plasmodium lineages and mosquito species fit the power‐law model with steeper slopes than found for the avian hosts. The lack of species–distance relationship in parasites suggests that other factors, such as the competence of specific vectors and habitat features, may be more important than distance. The decay in similarity with distance suggests that the sampled Plasmodium lineages and their potential hosts were not randomly distributed, but rather exhibited spatially predictable patterns. We discuss these results in the context of the effects that parasite generality may have on distribution patterns.
Ant communities on small tropical islands: effects of island size and isolation are obscured by habitat disturbance and ‘tramp’ ant species
Authors: Rizali Akhmad , Lohman David J. , Buchori Damayanti , Prasetyo Lilik Budi , Triwidodo Hermanu , Bos Merijn M. , Yamane Seiki , Schulze Christian H. 
Published: August 2009

AbstractAim  Comparisons among islands offer an opportunity to study the effects of biotic and abiotic factors on small, replicated biological communities. Smaller population sizes on islands accelerate some ecological processes, which may decrease the time needed for perturbations to affect community composition. We surveyed ants on 18 small tropical islands to determine the effects of island size, isolation from the mainland, and habitat disturbance on ant community composition.Location  Thousand Islands Archipelago (Indonesian name: Kepulauan Seribu) off Jakarta, West Java, Indonesia.Methods  Ants were sampled from the soil surface, leaf litter and vegetation in all habitat types on each island. Island size, isolation from the mainland, and land‐use patterns were quantified using GIS software. The presence of settlements and of boat docks were used as indicators of anthropogenic disturbance. The richness of ant communities and non‐tramp ant species on each island were analysed in relation to the islands’ physical characteristics and indicators of human disturbance.Results  Forty‐eight ant species from 5 subfamilies and 28 genera were recorded from the archipelago, and approximately 20% of the ant species were well‐known human‐commensal ‘tramp’ species. Islands with boat docks or human settlements had significantly more tramp species than did islands lacking these indicators of anthropogenic disturbance, and the diversity of non‐tramp species decreased with habitat disturbance.Main conclusions  Human disturbance on islands in the Thousand Islands Archipelago promotes the introduction and/or establishment of tramp species. Tramp species affect the composition of insular ant communities, and expected biogeographical patterns of ant richness are masked. The island with the greatest estimated species richness and the greatest number of unique ant species, Rambut Island, is a forested bird sanctuary, highlighting the importance of protected areas in preserving the diversity of species‐rich invertebrate faunas.
QseC‐mediated dephosphorylation of QseB is required for expression of genes associated with virulence in uropathogenic Escherichia coli
Authors: Kostakioti Maria , Hadjifrangiskou Maria , Pinkner Jerome S. , Hultgren Scott J. 
Published: August 2009

SummaryBacteria sense environmental cues and regulate gene expression accordingly so as to persist in diverse niches. QseC is a membrane sensor kinase shown in enterohemorrhagic Escherichia coli to respond to host and bacterial signals by phosphorylating the QseB response regulator at residue D51, resulting in QseB activation and presumably upregulation of virulence genes. We studied QseBC in uropathogenic E. coli (UPEC). UPEC establish infection by colonizing and invading bladder cells. After invasion, UPEC can escape into the cytoplasm where they can form intracellular bacterial communities. Deletion of qseC significantly attenuated intracellular bacterial community formation and virulence, whereas paradoxically qseB deletion did not impact pathogenesis. We found that QseB upregulates its own expression in the qseC mutant, arguing that it is activated even in the absence of QseC. However, expression of QseB, but not a QseB_D51A mutant, in the absence of QseC resulted in downregulation of type 1 pili, curli and flagella. We observed similar phenotypes with enterohemorrhagic E. coli, showing that this is not a UPEC‐specific phenomenon. Target gene expression is restored when QseC is present. We discovered that QseC has phosphatase activity required for QseB dephosphorylation. Thus, the QseC phosphatase capacity is critical for modulating QseB activity and subsequent gene expression.
(2S)‐Methylsuccinyl‐CoA dehydrogenase closes the ethylmalonyl‐CoA pathway for acetyl‐CoA assimilation
Authors: Erb Tobias J. , Fuchs Georg , Alber Birgit E. 
Published: August 2009

SummaryMany organic substrates are metabolized via acetyl‐coenzyme A (CoA) and enter central carbon metabolism at the level of this compound. We recently described the outlines of the ethylmalonyl‐CoA pathway, a new acetyl‐CoA assimilation strategy that operates in a number of bacteria such as Rhodobacter sphaeroides, Methylobacterium extorquens and streptomycetes and replaces the glyoxylate cycle. This new pathway involves a unique central reaction sequence catalysed by characteristic enzymes. Here, we identified and characterized (2S)‐methylsuccinyl‐CoA dehydrogenase from R. sphaeroides, a flavin adenine dinucleotide‐containing enzyme that catalyses the last unknown step in the central part of the ethylmalonyl‐CoA pathway, the oxidation of (2S)‐methylsuccinyl‐CoA to mesaconyl‐(C1)‐CoA. This enzyme is highly specific for its substrate and forms a distinct subgroup within the superfamily of flavin‐dependent acyl‐CoA dehydrogenases. Homology modelling and comparative sequence analyses with well‐studied members of this superfamily identified amino acids that may contribute to the narrow substrate specificity of (2S)‐methylsuccinyl‐CoA dehydrogenase. The central part of the ethylmalonyl‐CoA pathway was reconstituted in vitro using four recombinant enzymes. By this work, the ethylmalonyl‐CoA pathway and its stereochemical course have been completely solved. This allowed defining the minimum set of enzymes necessary for its operation and to screen for further organisms following this acetyl‐CoA assimilation strategy.
Rcs signalling‐activated transcription of rcsA induces strong anti‐sense transcription of upstream fliPQR flagellar genes from a weak intergenic promoter: regulatory roles for the anti‐sense transcript in virulence and motility
Authors: Wang Qingfeng , Harshey Rasika M. 
Published: August 2009

SummaryIn Salmonella enterica, an activated Rcs signalling system inhibits initiation of transcription of the flhD master operon. Under these conditions, where motility is shut down, microarray experiments showed an increased RNA signal for three flagellar genes –fliPQR– located upstream of rcsA. We show here that it is the anti‐sense (AS) strand of these genes that is transcribed, originating at a weak promoter in the intergenic region between fliR and rcsA. RcsA is an auxiliary regulator for the Rcs system, whose transcription is dependent on the response regulator RcsB. Rcs‐activated rightward transcription, but not translation, of rcsA is required for stimulation of leftward AS transcription. Our results implicate a combined action of RcsB and rcsA transcription in activating the AS promoter, likely by modulating DNA superhelicity in the intergenic region. We show that the AS transcript regulates many genes in the Rcs regulon, including SPI‐1 and SPI‐2 virulence and stress‐response genes. In the wild‐type strain the AS transcript is present in low amounts, independent of Rcs signalling. Here, AS transcription modulates complementary sense RNA levels and impacts swarming motility. It appears that the flagellar AS transcript has been co‐opted by the Rcs system to regulate virulence.
Borrelia burgdorferi small lipoprotein Lp6.6 is a member of multiple protein complexes in the outer membrane and facilitates pathogen transmission from ticks to mice
Authors: Promnares Kamoltip , Kumar Manish , Shroder Deborah Y. , Zhang Xinyue , Anderson John F. , Pal Utpal 
Published: August 2009

Summary Borrelia burgdorferi lipoprotein Lp6.6 is a differentially produced spirochete antigen. An assessment of lp6.6 expression covering representative stages of the infectious cycle of spirochetes demonstrates that the gene is solely expressed during pathogen persistence in ticks. Deletion of lp6.6 in infectious B. burgdorferi did not influence in vitro growth, or its ability to persist and induce inflammation in mice, migrate to larval or nymphal ticks or survive through the larval‐nymphal molt. However, Lp6.6‐deficient spirochetes displayed significant impairment in their ability to transmit from infected ticks to naïve mice, which was restored upon genetic complementation of the mutant with a wild‐type copy of lp6.6, establishing that Lp6.6 plays a role in pathogen transmission from ticks to mammals. Lp6.6 is a subsurface, yet highly abundant, outer membrane antigen. Two‐dimensional blue native/SDS‐PAGE coupled with liquid chromatography‐mass spectrometry (LC‐MS/MS) analysis and protein cross‐linking studies independently shows that Lp6.6 exists in multiple protein complexes in the outer membrane. We speculate that the function of Lp6.6 is connected to the physiological processes of these membrane complexes. Further characterization of differentially produced membrane antigens and associated protein complexes will likely aid in our understanding of the molecular details of B. burgdorferi persistence and transmission through a complex enzootic cycle.
Role of DegP for two‐partner secretion in Bordetella
Authors: Baud C. , Hodak H. , Willery E. , Drobecq H. , Locht C. , Jamin M. , Jacob‐Dubuisson F. 
Published: August 2009

SummarySorting of proteins destined to the surface or the extracellular milieu is mediated by specific machineries, which guide the protein substrates towards the proper route of secretion and determine the compartment in which folding occurs. In Gram‐negative bacteria, the two‐partner secretion (TPS) pathway is dedicated to the secretion of large proteins rich in β‐helical structure. The secretion of the filamentous haemagglutinin (FHA), a 230 kDa adhesin of Bordetella pertussis, represents a model TPS system. FHA is exported by the Sec machinery and transits through the periplasm in an extended conformation. From there it is translocated across the outer membrane by its dedicated transporter FhaC to finally fold into a long β‐helix at the cell surface in a progressive manner. In this work, we show that B. pertussis lacking the periplasmic chaperone/protease DegP has a strong growth defect at 37°C, and the integrity of its outer membrane is compromised. While both phenotypes are significantly aggravated by the presence of FHA, the chaperone activity of DegP markedly alleviates the periplasmic stress. In vitro, DegP binds to non‐native FHA with high affinity. We propose that DegP chaperones the extended FHA polypeptide in the periplasm and is thus involved in the TPS pathway.
Efficacy and cost‐effectiveness of cell saving blood autotransfusion in adult lumbar fusion
Authors: Savvidou C. , Chatziioannou S. N. , Pilichou A. , Pneumaticos S. G. 
Published: August 2009

summary.The objective of this study was to explore the use of cell saver blood autotransfusion in spinal surgery and to evaluate the efficacy and cost‐effectiveness of cell saver blood autotransfusion during lumbar spine fusion in adults. Specific indications for the use of cell saver in adult lumbar fusion surgery have not yet been clearly determined. A total of 50 consecutive candidates for posterolateral fusion with internal fixation were prospectively randomized into either receiving perioperatively cell saving autotransfusion (Group A: 25 patients) or not (Group B: 25 patients). The use of cell saving technique did not exclude the use of allogenic blood transfusion. Surgical indications were spinal stenosis, spondylolisthesis, adolescent idiopathic scoliosis, degenerative scoliosis and fractures. Medical and financial data were recorded. A cost‐analysis was performed. Patients in Group A received 880 ± 216 mL from cell saver and 175 ± 202 mL allogenic blood. The patients in Group B received 908 ± 244 mL allogenic blood. Blood volumes data collected were expressed in mean ± SD values. The cost of blood transfusion in Group A was 995 ±€447 per patient and 1220 ± 269 in Group B (P < 0.05). In elective lumbar fusion blood requirements can be satisfied with the use of autotransfusion. The use of cell saver appears to be useful and cost‐effective during most elective lumbar fusions.
Effectiveness of nanofiltration in removing small non‐enveloped viruses from three different plasma‐derived products
Authors: Menconi M. C. , Maggi F. , Zakrzewska K. , Salotti V. , Giovacchini P. , Farina C. , Andreoli E. , Corcioli F. , Bendinelli M. , Azzi A. 
Published: August 2009

summary.The objective of this study was to assess the ability of nanofiltration of albumin solution, prothrombin complex (PTC) and factor IX (FIX) to remove two small, non‐enveloped DNA viruses, parvovirus B19 (B19V) and torque teno virus (TTV). Virus removal was investigated with down‐scale experiments performed with sequential steps of 35‐nm and 15‐nm nanofiltrations of products spiked with virus DNA‐positive sera. Viral loads were determined by real‐time PCRs. The 15‐nm nanofiltration removed more than 4.0 B19V log from all the products, TTV was reduced of more than 3.0 log from albumin solution and FIX by 35‐nm and 15‐nm nanofiltrations, respectively, being viral DNA undetectable after these treatments. Traces of TTV were still found in PTC after the 15‐nm nanofiltration. In conclusion, nanofiltration can be efficacious in removing small naked viruses but, since viruses with similar features can differently respond to the treatment, a careful monitoring of large‐scale nanofiltration should be performed.