bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acyl homoserine lactone-based quorum sensing in a methanogenic archaeon
Authors: Zhang Guishan , Zhang Fan , Ding Gang , Li Jie , Guo Xiaopeng , Zhu Jinxing , Zhou Liguang , Cai Shichun , Liu Xiaoli , Luo Yuanming , Zhang Guifeng , Shi Wenyuan , Dong Xiuzhu 
Published: January 2012

Abstract
Acyl homoserine lactone (AHL)-based quorum sensing commonly refers to cell density-dependent regulatory mechanisms found in bacteria. However, beyond bacteria, this cell-to-cell communication mechanism is poorly understood. Here we show that a methanogenic archaeon, Methanosaeta harundinacea 6Ac, encodes an active quorum sensing system that is used to regulate cell assembly and carbon metabolic flux. The methanogen 6Ac showed a cell density-dependent physiology transition, which was related to the AHL present in the spent culture and the filI gene-encoded AHL synthase. Through extensive chemical analyses, a new class of carboxylated AHLs synthesized by FilI protein was identified. These carboxylated AHLs facilitated the transition from a short cell to filamentous growth, with an altered carbon metabolic flux that favoured the conversion of acetate to methane and a reduced yield in cellular biomass. The transcriptomes of the filaments and the short cell forms differed with gene expression profiles consistent with the physiology. In the filaments, genes encoding the initial enzymes in the methanogenesis pathway were upregulated, whereas those for cellular carbon assimilation were downregulated. A luxI–luxR ortholog filI–filR was present in the genome of strain 6Ac. The carboxylated AHLs were also detected in other methanogen cultures and putative filI orthologs were identified in other methanogenic genomes as well. This discovery of AHL-based quorum sensing systems in methanogenic archaea implies that quorum sensing mechanisms are universal among prokaryotes.
Cardiac troponin T levels and exercise stress testing in patients with suspected coronary artery disease: the Akershus Cardiac Examination (ACE) 1 study
Authors: Røysland Ragnhild , Kravdal Gunnhild , Høiseth Arne Didrik , Nygård Ståle , Badr Pirouz , Hagve Tor-Arne , Omland Torbjørn , Røsjø Helge 
Published: January 2012

Whether reversible ischaemia in patients referred for exercise stress testing and MPI (myocardial perfusion imaging) is associated with changes in circulating cTn (cardiac troponin) levels is controversial. We measured cTnT with a sensitive assay before, immediately after peak exercise and 1.5 and 4.5 h after exercise stress testing in 198 patients referred for MPI. In total, 19 patients were classified as having reversible myocardial ischaemia. cTnT levels were significantly higher in patients with reversible myocardial ischaemia on MPI at baseline, at peak exercise and after 1.5 h, but not at 4.5 h post-exercise. In patients with reversible ischaemia on MPI, cTnT levels did not change significantly after exercise stress testing [11.1 (5.2–14.9) ng/l at baseline compared with 10.5 (7.2–16.3) ng/l at 4.5 h post-exercise, P=0.27; values are medians (interquartile range)]. Conversely, cTnT levels increased significantly during testing in patients without reversible myocardial ischaemia [5.4 (3.0–9.0) ng/l at baseline compared with 7.5 (4.6–12.4) ng/l, P&lt;0.001]. In conclusion, baseline cTnT levels are higher in patients with MPI evidence of reversible myocardial ischaemia than those without reversible ischaemia. However, although cTnT levels increase during exercise stress testing in patients without evidence of reversible ischaemia, this response appears to be blunted in patients with evidence of reversible ischaemia. Mechanisms other than reversible myocardial ischaemia may play a role for acute exercise-induced increases in circulating cTnT levels.
Enhancing humoral responses to a malaria antigen with nanoparticle vaccines that expand T
fh
cells and promote germinal center induction
Authors: Moon James J. , Suh Heikyung , Li Adrienne V. , Ockenhouse Christian F. , Yadava Anjali , Irvine Darrell J. 
Published: January 2012

For subunit vaccines, adjuvants play a key role in shaping immunological memory. Nanoparticle (NP) delivery systems for antigens and/or molecular danger signals are promising adjuvants capable of promoting both cellular and humoral immune responses, but in most cases the mechanisms of action of these materials are poorly understood. Here, we studied the immune response elicited by NPs composed of multilamellar “stapled” lipid vesicles carrying a recombinant
Plasmodium vivax
circumsporozoite antigen, VMP001, both entrapped in the aqueous core and anchored to the lipid bilayer surfaces. Immunization with these particles and monophosphoryl lipid A (MPLA), a US Food and Drug Administration–approved immunostimulatory agonist for Toll-like receptor-4, promoted high-titer, high-avidity antibody responses against VMP001, lasting more than 1 y in mice at 10-fold lower doses than conventional adjuvants. Compared to soluble VMP001 mixed with MPLA, VMP001-NPs promoted broader humoral responses, targeting multiple epitopes of the protein and a more balanced Th1/Th2 cytokine profile from antigen-specific T cells. To begin to understand the underlying mechanisms, we examined components of the B-cell response and found that NPs promoted robust germinal center (GC) formation at low doses of antigen where no GC induction occurred with soluble protein immunization, and that GCs nucleated near depots of NPs accumulating in the draining lymph nodes over time. In parallel, NP vaccination enhanced the expansion of antigen-specific follicular helper T cells (T
fh
), compared to vaccinations with soluble VMP001 or alum. Thus, NP vaccines may be a promising strategy to enhance the durability, breadth, and potency of humoral immunity by enhancing key elements of the B-cell response.
Performance improvement of plasma actuators using asymmetric high voltage waveforms
Authors: Kotsonis M , Ghaemi S 
Published: January 2012

Abstract
An experimental study is conducted on high voltage waveforms used to power plasma actuators. Shapes that present an asymmetry between the two half cycles are investigated by means of induced thrust and velocity measurements. A parametric study is performed based on thrust measurements in order to find the optimum shape within the tested range. An asymmetric waveform which is made as a combination of sinusoidal and square shapes is found to increase produced thrust by almost 30% compared with the conventional sinusoidal waveform. The asymmetric waveform is further analysed using time-resolved particle image velocimetry in order to reveal the forcing mechanism governed by the shape differences. It is shown that the shape of the waveform has a significant effect on the performance of the actuator. Push and pull events occur within the actuation period and their respective strength and duration closely correlates with the shape of the waveform. It is found that the pull event is significantly weakened for the case of the optimized asymmetric waveform in comparison with the sinusoidal shape. This effectively increases the net momentum transfer and an improvement of approximately 40% in maximum induced velocity is achieved compared with sine waveform. Power consumption due to the asymmetric waveform is marginally increased which provides a significant increase in the actuator's relative efficiency.
Time and spatially resolved LIF of OH in a plasma filament in atmospheric pressure He–H2O
Authors: Verreycken T , van der Horst R M , Baede A H F M , Van Veldhuizen E M , Bruggeman P J 
Published: January 2012

Abstract
The production of OH in a nanosecond pulsed filamentary discharge generated in pin–pin geometry in a He–H2O mixture is studied by time and spatially resolved laser-induced fluorescence. Apart from the OH density the gas temperature and the electron density are also measured. Depending on the applied voltage the discharge is in a different mode. The maximum electron densities in the low- (1.3 kV) and high-density (5 kV) modes are 2 × 1021 m−3 and 7 × 1022 m−3, respectively. The gas temperature in both modes does not exceed 600 K. In the low-density mode the maximum OH density is at the centre of the discharge filament, while in the high-density mode the largest OH density is observed on the edge of the discharge. A chemical model is used to obtain an estimate of the absolute OH density. The chemical model also shows that charge exchange and dissociative recombination can explain the production of OH in the case of the high-density mode.
Magnetic field influence on pulsed air arc anode mass loss
Authors: Parkansky N , Beilis I I , Alterkop B , Boxman R L , Rosenberg Yu 
Published: January 2012

Abstract
Anode mass loss was studied in pulsed air arcs between two electrode pairs, 99.99% Ni/Ni and 99.5% Cu/Cu, in a transverse magnetic field. In both cases the anode mass loss decreased (by a factor of 2 for Cu and by a factor of 6 for Ni) when the magnetic field was increased up to 15–20 Oe and then remained approximately constant for Cu and decreased weakly for Ni. The observed dependences of anode mass loss were explained by the published behaviour of an arc motion in a magnetic field. The lattice parameter was decreased by the discharge treatment. The decrease was attributed to residual tensile stress produced on the arced surface. The lattice parameter of Ni increased with magnetic field, while for Cu it did not change substantially. The different behaviour is attributed to the magneto-plastic effect on magnetic Ni, which increases the plasticity with magnetic field.
The impact of sewage on environmental quality and the mesozooplankton community in a highly eutrophic estuary in Argentina
Authors: Dutto M. Sofía , López Abbate M. Celeste , Biancalana Florencia , Berasategui Anabela A. , Hoffmeyer Mónica S. 
Published: January 2012

Abstract
Dutto, M. S., López Abbate, M. C., Biancalana, F., Berasategui, A. A., and Hoffmeyer, M. S. 2012. The impact of sewage on environmental quality and the mesozooplankton community in a highly eutrophic estuary in Argentina. – ICES Journal of Marine Science, 69: 399–409. Eutrophication caused by human sewage is a growing phenomenon along coasts. Mesozooplankton abundance, community structure, and environmental quality were compared at two sites in the inner Bahía Blanca Estuary (BBE), Argentina, one receiving regional sewage discharge (Canal Vieja), and the other a non-impacted area (Bahía del Medio). Comparisons of mean abundance and multivariate analyses were performed to detect spatial and temporal variations in both environmental and biotic variables. Significantly higher amounts of nitrogen and phosphorus and lower oxygen and pH were recorded at Canal Vieja. Larvae of the detritivorous crab Neohelice granulata were more abundant at Canal Vieja, whereas the common estuarine copepod species Acartia tonsa was more abundant at Bahía del Medio, where the mesozooplankton community was typical for the estuary. Although mesozooplankton is likely to be adapted to the high organic matter content in the BBE, the environmental conditions at Canal Vieja appear to favour Neohelice granulata, and this species should be considered as a potential indicator of the impact of sewage in future monitoring programmes. Particulate organic carbon and chlorophyll a were not influenced by organic loading in this naturally eutrophic estuary.
The Developmental Trajectory of Leaflet Morphology in Wild Tomato Species
Authors: Chitwood Daniel H. , Headland Lauren R. , Kumar Ravi , Peng Jie , Maloof Julin N. , Sinha Neelima R. 
Published: January 2012

AbstractLeaves between species vary in their size, serration, complexity, and shape. However, phylogeny is not the only predictor of leaf morphology. The shape of a leaf is the result of intricate developmental processes, including heteroblastic progression (changes in leaf size and shape at different nodes) and the developmental stage of an organ. The leaflets that arise from complex leaves are additionally modified by their positioning along the proximal-distal axis of a leaf and whether they fall on the left or right side of leaves. Even further, leaves are environmentally responsive, and their final shape is influenced by environmental inputs. Here, we comprehensively describe differences in leaflet shape between wild tomato (Solanum section Lycopersicon) species using a principal component analysis on elliptical Fourier descriptors arising from &gt;11,000 sampled leaflets. We leverage differences in developmental rate to approximate a developmental series, which allows us to resolve the confounding differences in intrinsic leaflet form and developmental stage along positions of the heteroblastic leaf series and proximal-distal axis of leaves. We find that the resulting developmental trajectory of organs at different positions along these axes are useful for describing the changes in leaflet shape that occur during the shade avoidance response in tomato. We argue that it is the developmental trajectory, the changes in shape that occur over developmental time in organs reiterated at multiple positions, that is the relevant phenotype for discerning differences between populations and species, and to understand the underlying developmental processes that change during evolution.
Long term use of drugs affecting the renin‐angiotensin system and the risk of cancer: a population‐based case‐control study
Authors: Hallas Jesper , Christensen Rene , Andersen Morten , Friis Søren , Bjerrum Lars 
Published: January 2012

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• A recent meta‐analysis has suggested an increased risk of cancer among users of angiotensin receptor blockers.WHAT THIS STUDY ADDS• Within the limitations of an observational study there is no difference in the cancer incidence between users of drugs affecting the renin‐angiotensin system and users of other antihypertensives.• No consistent dose or duration dependency could be demonstrated for angiotensin reeptor blockers and angiotensin converting enzyme inhibitors.AIMS A recent meta‐analysis of clinical trials has demonstrated a small excess of cancers in persons who had been allocated to angiotensin receptor blockers (ARBs). We undertook this observational study to look at dose–response and dose–duration effects and look for specificity with respect to outcome. Use of angiotensin converting enzyme inhibitors (ACEIs) was included in the main analysis since ACEIs share pharmacological properties with ARBs.METHODS We identified 149 417 incident cancer cases in Denmark during the period 2000–2005. Four controls, matched by age and gender, were selected for each case by a risk‐set sampling. Data on medication were retrieved from the Danish National Prescription Registry. We defined long term exposure as at least 1000 defined daily doses redeemed within the past 5 years. Confounders were controlled by conditional logistic regression.RESULTS The odds ratio (OR) associating long term drug use with incident cancer was 1.12 (95% CI 1.06, 1.18), 1.17 (95% CI 1.14, 1.20), 1.23 (95% CI 1.20, 1.26), 1.18 (95% CI 1.14, 1.22), 1.25 (95% CI 1.22, 1.28), 1.37 (95% CI 1.21, 1.54), 1.29 (95% CI 1.22, 1.37) for ARBs, ACEIs, calcium channel blockers, β‐adrenoceptor blockers, thiazide diuretics and α‐adrenoceptor blockers. No consistent dose–duration or dose–response association could be demonstrated for ARBs or ACEIs.CONCLUSIONS The indication or possibly threshold for prescribing antihypertensives appears to be related to a small increase in cancer risk. The ARB‐cancer association is probably too weak to be addressed in observational studies, given their limitations.
Pharmacokinetics of linagliptin in subjects with hepatic impairment
Authors: Graefe‐Mody Ulrike , Rose Peter , Retlich Silke , Ring Arne , Waldhauser Lisa , Cinca Rodica , Woerle Hans‐Juergen 
Published: January 2012

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• Linagliptin is an oral, highly selective dipeptidyl peptidase‐4 (DPP‐4) inhibitor that was approved in the United States, Europe and elsewhere in 2011 for the treatment of type 2 diabetes mellitus.• The elimination of linagliptin is primarily non‐renal. Therefore, a potential effect of hepatic impairment on the elimination of linagliptin may have important implications for dosing recommendations.WHAT THIS STUDY ADDS• This study shows that mild, moderate or severe hepatic impairment did not result in an increase in linagliptin exposure after single and multiple dosing as compared with normal hepatic function.• No linagliptin dose adjustment is required in patients with any degree of hepatic impairment.AIM To investigate whether hepatic impairment affects linagliptin pharmacokinetics, pharmacodynamics and tolerability.METHOD This open label, parallel group, single centre study enrolled patients with mild (n= 8), moderate (n= 9) or severe (n= 8) hepatic impairment and healthy subjects (n= 8). Groups were matched with regard to age, weight and gender. Primary endpoints were linagliptin exposure following 5 mg linagliptin once daily for 7 days in patients with mild and moderate hepatic impairment vs. healthy subjects or after a single 5 mg dose for patients with severe hepatic impairment vs. healthy subjects.RESULTS In mild hepatic impairment, steady‐state linagliptin exposure was slightly lower than in healthy subjects [AUCτ,ss geometric mean ratio (GMR) 75.5%, 90% confidence interval (CI) 61.6%, 92.5%, and Cmax,ss GMR 64.4%, 90% CI 43.2%, 96.0%]. Exposure also tended to be lower in moderate hepatic impairment (AUCτ,ss GMR 85.5%, 90% CI 70.2%, 104.2% and Cmax,ss GMR 92.3%, 90% CI 62.8%, 135.6%). After a single dose, AUC(0,24 h) in patients with severe hepatic impairment was similar to that in healthy subjects (GMR 100.4%, 90% CI 75.0%, 134.3%) and Cmax was lower (GMR 77.0%, 90% CI 44.9%, 132.3%). Accumulation based on AUC or Cmax and renal excretion of unchanged linagliptin (≤7%) were comparable across groups. Median plasma DPP‐4 inhibition was similar in healthy subjects (91%), and patients with mild (90%) and moderate (89%) hepatic impairment at steady‐state trough concentrations, and in patients with severe hepatic impairment 24 h after a single dose (84%). Linagliptin was well tolerated.CONCLUSION Mild, moderate or severe hepatic impairment did not result in an increase in linagliptin exposure after single and multiple dosing compared with normal hepatic function. Dose adjustment with linagliptin is not required in patients with hepatic impairment.
Jumping through hoops – the cost of compliance on sole parents
Authors: McArthur Morag , Thomson Lorraine , Winkworth Gail 
Published: January 2012

ABSTRACTAustralian governments along with other western countries have made significant changes to the welfare system with a focus on encouraging sole parents on social security payments to move into paid work. This paper reports on in‐depth interviews with 48 sole parents about their experiences with the welfare‐to‐work process and with a range of other services. Although parents reported some positive encounters, they also described a range of negative experiences, including how they needed to repeatedly prove their entitlement to help, leaving them feel as if they were undeserving of support. The study has demonstrated that it is often the most vulnerable parents who feel under close scrutiny and who have to work extra hard to get the help they need. These experiences can also see them disengaging from services. The findings show how the current policy environment adds to the complexity of sole parents' lives reinforcing their disadvantage.
Co‐producing innovation or innovating co‐production? Responding to the contact needs of non‐resident parents in the Republic of Ireland
Authors: Coen Liam , Kearns Noreen 
Published: January 2012

ABSTRACTThe empowerment and participation of children and families in both the design and the delivery of services oriented towards them is now an accepted norm, if not always the accepted practice. Yet, challenges still remain, particularly where parents are separated and contact issues are problematic. Although contact centres are common in some Western countries including Australia, New Zealand, the UK, France, and the USA, this is not the case in the Republic of Ireland. The relatively recent introduction of divorce, increases in separation and childbirth outside of marriage have led to the need for service planners to respond to the growing issue of non‐resident contact with children. Using Bovaird's co‐production framework, the purpose of this paper is to outline and discuss specific findings relating to service user involvement emanating from a formative evaluation of an innovative supported contact service in Ireland. What emerges from the findings is a picture of co‐production where the broad parameters of the service are professionally defined and where the specifics of service user involvement in delivery vary from family to family but within the bounds of professional control.
Quality of life measures for food allergy
Authors: Flokstra‐de Blok B. M. J. , Dubois A. E. J. 
Published: January 2012

SummaryFood allergy has become an emerging health problem in Western societies. Although food allergy is characterized by a relatively low mortality and an almost continual absence of physical symptoms, food allergic patients are continually confronted with the possibility of potentially severe reactions and the necessity of dietary vigilance. Health‐related quality of life (HRQL) may be the only meaningful outcome measure available for food allergy measuring this continuous burden. HRQL may be measured with generic or disease‐specific instruments. Generic instruments may be relatively unresponsive to differences or changes in health status, whereas disease‐specific instruments are generally more sensitive for relatively subtle problems related to a particular illness. Recently, a number of disease‐specific questionnaires have become available to measure the HRQL of food allergic patients. An important area for further research is the interpretation of the outcome of HRQL measures. In this respect, the minimal clinically important difference (MCID) is of special interest. In combination with the numbers needed to treat (NNT), this may give an ultimate insight into the clinical relevance of an intervention. Since there is still no cure for food allergy, the only available treatment is strict avoidance of the culprit food and provision of emergency treatment. The double‐blind placebo‐controlled food challenge (DBPCFC) is considered to be the gold standard for diagnosing food allergy. A number of studies have investigated the perceptions of parents whose children underwent a DBPCFC. In contrast to the parental perception, there is much currently still unknown about the effects of undergoing a DBPCFC in the perceptions of patients. In addition to the research on MCID and NNT of food allergy HRQL questionnaires, further research should focus on deriving quality‐adjusted life years (QALYs) from food allergy HRQL questionnaires and the application of food allergy HRQL questionnaires at the individual patient level in clinical practice.