bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of contact‐dependent CD8+ regulatory T cells through stimulation with staphylococcal and streptococcal superantigens*
Authors: Taylor Amanda L. , Cross Elizabeth L. A. , Llewelyn Martin J. 
Published: October 2011

SummaryThe bacterial superantigen exotoxins of Staphylococcus aureus and Streptococcus pyogenes are potent stimulators of polyclonal T‐cell proliferation. They are the causes of toxic shock syndrome but also induce CD25+ FOXP3+ regulatory cells in the CD4 compartment. Several studies have recently described different forms of antigen‐induced regulatory CD8+ T cells in the context of inflammatory diseases and chronic viral infections. In this paper we show that bacterial superantigens are potent inducers of human regulatory CD8+ T cells. We used four prototypic superantigens of S. aureus (toxic shock syndrome toxin‐1 and staphylococcal enterotoxin A) and Str. pyogenes (streptococcal pyrogenic exotoxins A and K/L). At concentrations below 1 ng/ml each toxin triggers concentration‐dependent T‐cell receptor Vβ‐specific expression of CD25 and FOXP3 on CD8+ T cells. This effect is independent of CD4+ T‐cell help but requires antigen‐presenting cells for maximum effect. The cells also express the activation/regulatory markers cytotoxic T‐lymphocyte antigen‐4 and glucocorticoid‐induced tumour necrosis factor receptor‐related protein and skin homing adhesins CD103 and cutaneous lymphocyte‐associated antigen. Superantigen‐induced CD25+ FOXP3+ CD8+ T cells were as potent as freshly prepared naturally occurring CD4+ regulatory T cells in suppressing proliferation of CD4+ CD25− T cells in response to anti‐CD3 stimulation. Although superantigen‐induced CD8+ CD25+ FOXP3+ express interleukin‐10 and interferon‐γ their suppressive function is cell contact dependent. Our findings indicate that regulatory CD8+ T cells may be a feature of acute bacterial infections contributing to immune evasion by the microbe and disease pathogenesis. The presence and magnitude of regulatory CD8+ T‐cell responses may represent a novel biomarker in such infections. Superantigen‐induced regulatory CD8+ T cells also have therapeutic potential.
Catchment‐scale peatland restoration benefits stream ecosystem biodiversity
Authors: Ramchunder Sorain J. , Brown Lee E. , Holden Joseph 
Published: October 2011

Summary1. Drainage of peat‐dominated catchments across the world has caused widespread degradation of peat and freshwater ecosystem services. In the UK, an estimated £500 million has been spent over the last decade blocking drains to reverse these changes. The practice raises water‐tables to induce rewetting and promote peat aggradation. However, the potential benefits for impacted ecosystems such as streams remain unknown.2. This study examined stream physicochemistry and benthic macroinvertebrates across peatland catchments with artificial drainage networks, or drains that have recently been blocked, and compared these with intact peatland sites having no history of drainage.3. Streams in artificially drained catchments were characterised by more benthic fine particulate organic matter (FPOM), higher suspended sediment concentrations and finer bed sediments (D50) than in drain‐blocked and intact catchments.4. Drained sites had higher abundance of Diptera (Simuliidae and Chironomidae) larvae, and lower abundance of Ephemeroptera, Plecoptera and Trichoptera larvae, than drain‐blocked sites. In contrast, streams in drain‐blocked catchments had macroinvertebrate communities broadly similar to intact sites in terms of taxon richness, overall species composition and community structure. These changes were associated with lower suspended sediment and benthic FPOM concentrations following drain‐blocking.5. Synthesis and applications. This study has shown changes in the structure of stream benthic macroinvertebrate assemblages linked to increases in benthic particulate organic matter and suspended sediment following peatland drainage. However, these effects seem to be reversible following catchment‐scale restoration by drain‐blocking. Drain‐blocking therefore appears to benefit not only peatland soil, vegetation and hydrological ecosystem services but also stream water quality and biodiversity. The numerous agencies undertaking peatland restoration should consider implementing detailed pre‐ and post‐blocking monitoring of streams to further improve our understanding of the mechanisms through which peatland management affects stream biodiversity and biological recovery dynamics, refine drain‐blocking practices, and inform aquatic conservation and management strategies.
Nursing academicians' attitudes towards work life and their personality traits
Authors: YILDIRIM S. , ÇAM O. 
Published: October 2011

Accessible summary
Job‐ and organization‐related attitude can be defined as a person's general attitude towards his/her job and organization. It can also be defined as the combination of the feelings, opinions and behaviours of the employee towards the job and the organization.
The review of literature shows that, in general, the factors affecting the features of job‐ and organization‐related attitude can be divided into three subtitles: sociodemographic characteristics, professional and institutional characteristics, and personal characteristics.
In order to help develop a positive attitude towards job and organization in nursing academicians, it is important to establish the factors affecting the features of this attitude.
This study is a descriptive and relational study, aiming to investigate the relationship between personality characteristics and job‐ and organization‐related attitude in nursing academicians in Turkey.
The study sample included 287 nursing academicians who worked in 14 School of Nurses in the Universities of Turkey.
The job‐ and organization‐related attitude of the nursing academicians is affected by their socio‐economic status, working year, academic title, the temperament feature of novelty seeking and persistence, and the character feature of self‐directedness and cooperativeness.
AbstractThe purpose of this study was to determine the relationship between attitudes of nursing academicians towards job and organization and their personality traits. The research included 287 nursing academicians who worked in 14 School of Nurses in the Universities of Turkey. A descriptive information form, Job and Organization Related Attitude Scale and Temperament and Character Inventory were used as data collection tools. It has been determined that attitudes of nursing academicians towards job and organization and their personality traits depended upon socio‐economic status, working year, academic title, the temperament feature of novelty seeking and persistence, and the character feature of self‐directedness and cooperativeness.
Performance of Acoustic Radiation Force Impulse imaging for the staging of liver fibrosis: a pooled meta‐analysis
Authors: Friedrich‐Rust M. , Nierhoff J. , Lupsor M. , Sporea I. , Fierbinteanu‐Braticevici C. , Strobel D. , Takahashi H. , Yoneda M. , Suda T. , Zeuzem S. , Herrmann E. 
Published: October 2011

Summary. Acoustic Radiation Force Impulse (ARFI) imaging is a novel ultrasound‐based elastography method that is integrated in a conventional ultrasound machine enabling the exact localization of measurement site. It might present an alternative method to transient elastography for the noninvasive assessment of liver fibrosis. At present, studies with small patient population have shown promising results. A systematic review and meta‐analysis of pooled patient data were performed to evaluate the overall performance of ARFI for the staging of liver fibrosis. Literature databases were searched up to 10/2010. The authors of the original publication were contacted, and the original patient data were requested. A meta‐analysis was performed using a random effect meta‐analytic method for diagnostic tests. In addition, available data comparing ARFI with FibroScan with the DeLong test were evaluated. Literature search yielded nine full‐paper publications evaluating ARFI while using liver biopsy as reference method. Original patient data were available from eight studies including 518 patients. The mean diagnostic accuracy of ARFI expressed as areas under ROC curves (AUROC) was 0.87 for the diagnosis of significant fibrosis (F ≥ 2), 0.91 for the diagnosis of severe fibrosis (F ≥ 3), and 0.93 for the diagnosis of cirrhosis. ARFI can be performed with good diagnostic accuracy for the noninvasive staging of liver fibrosis.
An amino‐terminal signal peptide of Vfr protein negatively influences RopB‐dependent SpeB expression and attenuates virulence in Streptococcus pyogenes
Authors: Shelburne III Samuel A. , Olsen Randall J. , Makthal Nishanth , Brown Nicholas G. , Sahasrabhojane Pranoti , Watkins Ebru M. , Palzkill Timothy , Musser James M. , Kumaraswami Muthiah 
Published: October 2011

SummaryStreptococcal pyrogenic exotoxin B (SpeB) is an extracellular cysteine protease that is a critical virulence factor made by the major human pathogen group A Streptococcus (GAS). speB expression is dependent on the regulator of proteinase B (RopB) and is upregulated with increasing cell density and during infection. Because computer modelling suggested significant structural similarity between RopB and peptide‐sensing regulatory proteins made by other Gram‐positive bacteria, we hypothesized that speB expression is influenced by RopB–peptide interactions. Inactivation of the gene (vfr) encoding the virulence factor related (Vfr) protein resulted in increased speB transcript level during the exponential growth phase, whereas provision of only the amino‐terminal region of Vfr comprising the secretion signal sequence in trans restored a wild‐type speB expression profile. Addition of the culture supernatant from a Vfr signal peptide‐expressing GAS strain restored wild‐type speB transcript level to a vfr‐inactivated isogenic mutant strain. A distinct peptide in the Vfr secretion signal sequence specifically bound to recombinant RopB. Finally, overexpression of the Vfr secretion signal sequence significantly decreased speB transcript level and attenuated GAS virulence in two mouse models of invasive infection. Taken together, these data delineate a previously unknown small peptide‐mediated regulatory system that controls GAS virulence factor production.
Ubiquitin and ubiquitin‐modified proteins activate the Pseudomonas aeruginosa T3SS cytotoxin, ExoU
Authors: Anderson David M. , Schmalzer Katherine M. , Sato Hiromi , Casey Monika , Terhune Scott S. , Haas Arthur L. , Feix Jimmy B. , Frank Dara W. 
Published: October 2011

SummaryPseudomonas aeruginosa is an opportunistic Gram‐negative pathogen that possesses a type III secretion system (T3SS) critical for evading innate immunity and establishing acute infections in compromised patients. Our research has focused on the structure–activity relationships of ExoU, the most toxic and destructive type III effector produced by P. aeruginosa. ExoU possesses phospholipase activity, which is detectable in vitro only when a eukaryotic cofactor is provided with membrane substrates. We report here that a subpopulation of ubiquitylated yeast SOD1 and other ubiquitylated mammalian proteins activate ExoU. Phospholipase activity was detected using purified ubiquitin of various chain lengths and linkage types; however, free monoubiquitin is sufficient in a genetically engineered dual expression system. The use of ubiquitin by a bacterial enzyme as an activator is unprecedented and represents a new aspect in the manipulation of the eukaryotic ubiquitin system to facilitate bacterial replication and dissemination.
Sub‐Cambrian pedogenesis recorded in weathering profiles of the Arabian‐Nubian Shield
Authors: SANDLER AMIR , TEUTSCH NADYA , AVIGAD DOV 
Published: October 2011

AbstractAltered crystalline rocks occur at the peneplain exposed in southern Israel and in other localities across North Africa and Arabia where they underlie an extensive blanket of Cambro–Ordovician sandstones. This study focuses on the petrography, mineralogy and geochemistry of top basement rocks of the northern Arabian‐Nubian Shield. The altered rocks are shown to be weathering profiles that can be subdivided into three horizons interpreted as apparently unweathered granite, or saprock, which grades upwards to a saprolite, topped by a thin clayey plasmic zone. The plasmic zone is enriched in iron and aluminium and is depleted in silicon, calcium, magnesium and potassium relative to the underlying saprolite. The chemical index of alteration increases upward, but does not exceed 90 and, therefore, lags behind values observed in strongly leached present‐day tropical soils. Petrographic examinations reveal iron mobility under local fluctuating redox conditions, similar to modern and Proterozoic soils. A variety of birefringence fabrics induced by shrinkage and expansion of clays during wetting and drying cycles and clay illuviation strongly indicate pedogenic processes rather than a post‐depositional alteration. Illite and ordered illite‐smectite phases coexist with smectitic illite‐smectite in the lower part of the saprolite and with kaolinite in the plasmic zone, in line with increasing chemical index of alteration. Observations are in accordance with the current profile being a remnant of a thick weathering profile whose top was truncated by fluvial incision just prior to deposition of the overlying Early Cambrian sequence. A previously documented Devonian thermal event reaching temperatures of at least 200°C overprinted the studied rocks. During burial diagenesis, illitization affected original smectite rather than kaolinite. However, in spite of the elevated temperatures, illitization was incomplete implying restricted potassium addition. The sub‐Cambrian weathering reflects warm and humid conditions in a tropical or sub‐tropical climate, in line with several plate reconstructions placing Israel at low latitudes during Cambrian time.
Kilometre‐scale sand injectites in the intracratonic Murzuq Basin (South‐west Libya): an igneous trigger?
Authors: MOREAU JULIEN , GHIENNE JEAN FRANÇOIS , HURST ANDREW 
Published: October 2011

AbstractMount Telout, situated at the edge of the Murzuq Basin, is a 325 m high conical hill within a circular collapse structure that records 0·5 km3 of sand intrusion into Silurian shales. Based on a comparison with other similar circular collapse structures around the Murzuq Basin, it is argued that sand injection in the form of pipes occurred during the Devonian. The overpressures triggering the process are inferred to result from a combination of: (i) tectonic uplift at a basin scale that initially focused regional ground water flows; and (ii) igneous intrusion within the sand‐rich Cambrian–Ordovician strata. The palaeorelief buried under the regionally extensive Silurian shales may have locally focused overpressures and localized sand injection at the 1 to 10 km scale. The Mount Telout injected sandbody and related features offer exceptional, seismic‐scale outcrop analogues for sand injections that are often identified in seismic reflection data. Large‐scale sand injections might be essential in petroleum exploration of the North African Lower Palaeozoic basins as they form seal‐bypass systems.
A switch in Ca2+ spiking signature is concomitant with endosymbiotic microbe entry into cortical root cells of Medicago truncatula
Authors: Sieberer Björn J. , Chabaud Mireille , Fournier Joëlle , Timmers Antonius C.J. , Barker David G. 
Published: October 2011

SummaryCa2+ spiking is a central component of a common signaling pathway that is activated in the host epidermis during initial recognition of endosymbiotic microbes. However, it is not known to what extent Ca2+ signaling also plays a role during subsequent root colonization involving apoplastic transcellular infection. Live‐tissue imaging using calcium cameleon reporters expressed in Medicago truncatula roots has revealed that distinct Ca2+ oscillatory profiles correlate with specific stages of transcellular cortical infection by both rhizobia and arbuscular mycorrhizal fungi. Outer cortical cells exhibit low‐frequency Ca2+ spiking during the extensive intracellular remodeling that precedes infection. This appears to be a prerequisite for the formation of either pre‐infection threads or the pre‐penetration apparatus, both of which are fully reversible processes. A transition from low‐ to high‐frequency spiking is concomitant with the initial stages of apoplastic cell entry by both microbes. This high‐frequency spiking is of limited duration in the case of rhizobial infection and is completely switched off by the time transcellular infection by both microsymbionts is completed. The Ca2+ spiking profiles associated with both rhizobial and arbuscular mycorrhizal cell entry are remarkably similar in terms of periodicity, suggesting that microbe specificity is unlikely to be encoded by the Ca2+ signature during this particular stage of host infection in the outer cortex. Together, these findings lead to the proposal that tightly regulated Ca2+‐mediated signal transduction is a key player in reprogramming root cell development at the critical stage of commitment to endosymbiotic infection.
Incidence of severe acute maternal morbidity associated with abortion: a systematic review
Authors: Adler A. J. , Filippi V. , Thomas S. L. , Ronsmans C. 
Published: October 2011

SummaryObjective  To systematically review articles describing complications of abortion in settings where abortions are thought to be unsafe and to determine the incidence of severe acute maternal morbidity (SAMM) attributed to abortion at the population level.Methods  We searched relevant databases using search terms related to abortion and complications. We included population‐representative studies that listed complications of abortion. We extracted data on the definitions and numbers of severe complications and SAMM, and we report abortion complication rates (per 100 000 women of reproductive age) and ratios (per 100 000 live births) for SAMM, severe complications and any complications.Results  We included 15 studies representing eleven countries (six in Africa, four in Asia and one in Latin America). We found a median abortion ratio of SAMM of 237 (range 91–1892) per 100 000 live births and a median abortion ratio of severe complications of 596 (range 435–5298). There was a great degree of heterogeneity between definitions and study populations.Conclusions  The burden of SAMM attributed to abortion is much greater than what is reported for deaths caused by abortion. However, the great heterogeneity in definitions makes it difficult to draw firm conclusions. We call for future work on the burden of unsafe abortion to use strict definitions of SAMM.
The role of sexually transmitted infections in the evolution of the South African HIV epidemic
Authors: Johnson Leigh F. , Dorrington Rob E. , Bradshaw Debbie , Coetzee David J. 
Published: October 2011

SummaryObjectives  To assess the extent to which sexually transmitted infections (STIs) have contributed to the spread of HIV in South Africa and to estimate the extent to which improvements in STI treatment have reduced HIV incidence.Methods  A mathematical model was used to simulate interactions between HIV and six other STIs (genital herpes, syphilis, chancroid, gonorrhoea, chlamydial infection and trichomoniasis) as well as bacterial vaginosis and vaginal candidiasis. The effects of STIs on HIV transmission probabilities were assumed to be consistent with meta‐analytic reviews of observational studies, and the model was fitted to South African HIV prevalence data.Results  The proportion of new HIV infections in adults that were attributable to curable STIs reduced from 39% (uncertainty range: 24–50%) in 1990 to 14% (8–18%) in 2010, while the proportion of new infections attributable to genital herpes increased. Syndromic management programmes are estimated to have reduced adult HIV incidence by 6.6% (3.3–10.3%) between 1994 and 2004, by which time syndromic management coverage was 52%. Had syndromic management been introduced in 1986, with immediate achievement of 100% coverage and a doubling of the rate of health seeking, HIV incidence would have reduced by 64% (36–82%) over the next decade, but had the same intervention been delayed until 2004, HIV incidence would have reduced by only 5.5% (2.8–9.0%).Conclusions  Sexually transmitted infections have contributed significantly to the spread of HIV in South Africa, but STI control efforts have had limited impact on HIV incidence because of their late introduction and suboptimal coverage.
Sown grass strips harbour high weed diversity but decrease weed richness in adjacent crops
Authors: CORDEAU S , PETIT S , REBOUD X , CHAUVEL B 
Published: October 2011

Cordeau S, Petit S, Reboud X & Chauvel B (2011). Sown grass strips harbour high weed diversity but decrease weed richness in adjacent crops. Weed Research 52, 88–97.SummarySown grass strips have been widely established on field margins across France, because of their expected environmental benefits. They may also enhance the diversity of plant species in the adjacent boundary by buffering them from agricultural practices. However, the strips could act as an extended reservoir for weeds and increase their dispersal into the field. This study evaluated the impact of a 5‐m‐wide sown grass strip on (i) the weed richness, abundance and diversity of both boundary and field adjacent habitats and on (ii) the width of the edge zone within the field, defined as the zone where boundary habitats impact the flora in the field. We surveyed the flora in 10 fields along continuous transects running from the boundary toward the centre of the field on opposite sides of each field, one side with a sown grass strip and one side without. The establishment of sown grass strips did not change the overall species richness at the field scale, but modified its distribution in the different habitats. In the boundaries, plant species richness, total abundance or diversity (Shannon index) remained unchanged when a sown grass strip was present, whereas these indicators sharply decreased in the crop edge (−10.9 species and −86.4 individuals per 1.25 m2) and in the field margin (−3.6 species and −9.6 individuals per 1.25 m2) where the grass strip was present. Sown grass strips also significantly decreased the width of the edge zone, from 6.5 to 1.5 m for species richness and from 12 to 1 m for species diversity, demonstrating a decrease in weed ingress into the crop.