bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short‐term soil carbon sink potential of oil palm plantations
Authors: Smith Daniel R. , Townsend Toby J. , Choy Amanda W. K. , Hardy Ian C. W. , Sjögersten Sofie 
Published: April 2012

AbstractOil palm plantations cover ≈14.6 million ha worldwide and the total area under cultivation is expected to increase during the 21st century . Indonesia and Malaysia together account for 87% of global palm oil production and the combined harvested area in these countries has expanded by 6.5 million ha since 1990. Despite this, soil C cycling in oil palm systems is not well quantified but such information is needed for C budget inventories. We quantified soil C storage (root biomass, soil organic matter (SOM) and microbial biomass) and losses [potential soil respiration (Rs) and soil surface CO2 flux (Fs)] in mineral soils from an oil palm plantation chronosequence (11–34 years since planting) in Selangor, Malaysia. There were no significant effects of plantation age on SOM, microbial biomass, Rs or Fs, implying soil C was in dynamic equilibrium over the chronosequence. However, there was a significant increase in root biomass with plantation age, indicating a short‐term C sink. Across the chronosequence, Rs was driven by soil moisture, soil particle size, root biomass and soil microbial biomass N but not microbial biomass C. This suggests that the nutrient status of the microbial community may be of equal or greater importance for soil CO2 losses than substrate availability and also raises particular concerns regarding the addition of nitrogenous fertilizer, i.e. increased yields will be associated with increased soil CO2 emissions. To fully assess the impact of oil palm plantations on soil C storage, initial soil C losses following land conversion (e.g. from native forest or other previous plantations) must be accounted for. If initial soil C losses are large, our data show that there is no accumulation of stable C in the soil as the plantation matures and hence the conversion to oil palm would probably represent a net loss of soil C.
Environment may be the source of Flavobacterium columnare outbreaks at fish farms
Authors: Kunttu Heidi M. T. , Sundberg Lotta‐Riina , Pulkkinen Katja , Valtonen E. Tellervo 
Published: April 2012

SummaryFlavobacterium columnare, causing columnaris disease, was isolated for the first time from free water and biofilms in the environment outside fish farms. Fourteen isolates were found from Central Finland from a river by a water intake of a salmonid farm and 400 m upstream of the farm. One isolate was from a lake not under the influence of any fish farming. The bacterium could not be isolated from five other lakes in Central Finland or from three lakes in Eastern Finland, none of them in use for fish farming. Among the environmental isolates there was both genetic variability and difference in virulence, but the isolates were less virulent than the isolates originating from a disease outbreak at a fish farm. The isolates were able to survive for months outside the fish host and also to change their colony morphology, a phenomenon probably used as a survival strategy for F. columnare. This indicates that waters upstream of fish farms are a potential source of columnaris outbreaks at the farms during the summer. The results support the hypothesis that fish farms and farming practices may select for the virulent strains of F. columnare occurring in environmental waters to cause the infections at the farms.
Mandibular angle fractures during third molar removal: a report of two cases
Authors: Özçakir‐Tomruk C , Arslan A 
Published: April 2012

AbstractAlthough fracture of the tooth during surgical removal is common, mandibular fracture during lower third molar removal is an unusual and major complication. Possible aetiologies are age, gender, the position of the tooth, uncontrolled excessive force applied, insufficient surgical experience and improper instrumentation. Symptoms can vary widely and treatment options range from prescription of a soft diet to surgical treatment by open reduction and internal fixation. We present two cases of the treatment and follow‐up of fracture of the angle region of the mandible during removal.
Intestinal transporters for endogenic and pharmaceutical organic anions: the challenges of deriving in-vitro kinetic parameters for the prediction of clinically relevant drug–drug interactions
Authors: Grandvuinet Anne Sophie , Vestergaard Henrik Tang , Rapin Nicolas , Steffansen Bente 
Published: April 2012

Abstract

Objectives
This review provides an overview of intestinal human transporters for organic anions and stresses the need for standardization of the various in-vitro methods presently employed in drug–drug interaction (DDI) investigations.

Key findings
Current knowledge on the intestinal expression of the apical sodium-dependent bile acid transporter (ASBT), the breast cancer resistance protein (BCRP), the monocarboxylate transporters (MCT) 1, MCT3-5, the multidrug resistance associated proteins (MRP) 1–6, the organic anion transporting polypetides (OATP) 2B1, 1A2, 3A1 and 4A1, and the organic solute transporter α/β (OSTα/β) has been covered along with an overview of their substrates and inhibitors. Furthermore, the many challenges in predicting clinically relevant DDIs from in-vitro studies have been discussed with focus on intestinal transporters and the various methods for deducting in-vitro parameters for transporters (Km/Ki/IC50, efflux ratio). The applicability of using a cut-off value (estimated based on the intestinal drug concentration divided by the Ki or IC50) has also been considered.

Summary
A re-evaluation of the current approaches for the prediction of DDIs is necessary when considering the involvement of other transporters than P-glycoprotein. Moreover, the interplay between various processes that a drug is subject to in-vivo such as translocation by several transporters and dissolution should be considered.
Optimized generation of high resolution breast anthropomorphic software phantoms
Authors: Pokrajac David D. , Maidment Andrew D. A. , Bakic Predrag R. 
Published: April 2012

Purpose:The authors present an efficient method for generating anthropomorphic software breast phantoms with high spatial resolution. Employing the same region growing principles as in their previous algorithm for breast anatomy simulation, the present method has been optimized for computational complexity to allow for fast generation of the large number of phantoms required in virtual clinical trials of breast imaging.Methods:The new breast anatomy simulation method performs a direct calculation of the Cooper's ligaments (i.e., the borders between simulated adipose compartments). The calculation corresponds to quadratic decision boundaries of a maximuma posteriori classifier. The method is multiscale due to the use of octree‐based recursive partitioning of the phantom volume. The method also provides user‐control of the thickness of the simulated Cooper's ligaments and skin.Results:Using the proposed method, the authors have generated phantoms with voxel size in the range of (25–1000 μm)3/voxel. The power regression of the simulation time as a function of the reciprocal voxel size yielded a log‐log slope of 1.95 (compared to a slope of 4.53 of our previous region growing algorithm).Conclusions:A new algorithm for computer simulation of breast anatomy has been proposed that allows for fast generation of high resolution anthropomorphic software phantoms.
Time‐delayed summation as a means of improving resolution on fast rotating computed tomography systems
Authors: Nowak Tristan , Hupfer Martin , Althoff Felix , Brauweiler Robert , Eisa Fabian , Steiding Christian , Kalender Willi A. 
Published: April 2012

Purpose:Modern computed tomography (CT) systems are supporting increasingly fast rotation speeds, which are a prerequisite for fast dynamic acquisition, e.g. in perfusion imaging, and for new modalities such as dedicated breast CT, where breathhold scanning is indicated. However, not all detector technologies are supporting the high frame rates that are necessary to retain high resolution for objects far away from the isocenter. Even on systems that would support a sufficiently high frame rate, the necessary bandwidth of the data transfer from the rotating gantry stills remains challenging. The authors evaluated a pixel shifting technique termed time‐delayed summation (TDS) as a method of increasing resolution on fast rotating CT systems without the need to increase the frame rate.Methods:In TDS mode, detector pixel values are shifted along rows during image acquisition to compensate for detector motion. In order to fully exploit TDS, focal spot position control (FSC) was used in combination with TDS. FSC applies a counter movement to the x‐ray focal spot during image acquisition such that it is kept fixed in space. As a proof of concept, measurements were performed on a prototype photon counting detector capable of TDS. The detector was mounted on a movable table and a gold wire phantom was imaged with different TDS settings and detector velocities. Additionally, simulations of a broad range of TDS and FSC settings on two different modalities, a clinical CT scanner and a breast CT scanner, and two different detector geometries, flat and cylindrical, were performed to assess the gain in resolution and contrast in cylindrical water phantoms containing a small wire at distances from the phantom center varied from 5% to 90% of the phantom radius. As figures of merit, the modulation transfer function (MTF) at 10% and the maximum contrast were used and compared against the respective values when using step‐and‐shoot acquisition, which means stopping the rotation when a projection image is acquired.Results:Measurements showed that detector movement and the resulting blurring of the wire projections were compensated to the expected degree when using the appropriate number of TDS shifts per frame (TDS factor). Using simulations it was found that when using the optimal TDS factor, over 90% of the resolution achieved in step‐and‐shot mode was reached for all investigated wire positions. TDS showed better performance on a cylindrical detector that on the same system with a flat detector. TDS factors that were deviating from the optimum by more than 1 shift led to a performance below that of standard continuous acquisition.Conclusions:The findings of this study encourage the combined usage of TDS and FSC in systems that require fast rotation. The integration of TDS in state‐of‐the‐art x‐ray detectors is feasible.
Summary of Ceftaroline Activity against Pathogens in the United States, 2010: Report from the Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) Surveillance Program
Authors: Flamm Robert K. , Sader Helio S. , Farrell David J. , Jones Ronald N. 
Published: April 2012

ABSTRACT

The
A
ssessing
W
orldwide
A
ntimicrobial
R
esistance
E
valuation (AWARE) surveillance program is a sentinel resistance monitoring system designed to track the activity of ceftaroline and comparator agents. In the United States, a total of 8,434 isolates were collected during the 2010 surveillance program from 65 medical centers distributed across the nine census regions (5 to 10 medical centers per region). All organisms were isolated from documented infections, including 3,055 (36.2%) bloodstream infections, 2,282 (27.1%) respiratory tract infections, 1,965 (23.3%) acute bacterial skin and skin structure infections, 665 (7.9%) urinary tract infections, and 467 (5.5%) miscellaneous other infection sites. Ceftaroline was the most potent β-lactam agent tested against staphylococci. The MIC
90
values were 1 μg/ml for methicillin-resistant
Staphylococcus aureus
(MRSA; 98.4% susceptible) and 0.5 μg/ml for methicillin-resistant coagulase-negative staphylococci (CoNS). Ceftaroline was 16- to 32-fold more potent than ceftriaxone against methicillin-susceptible staphylococcal strains. All staphylococcus isolates (
S. aureus
and CoNS) were inhibited at ceftaroline MIC values of ≤2 μg/ml. Ceftaroline also displayed potent activity against streptococci (MIC
90
, 0.015 μg/ml for beta-hemolytic streptococci; MIC
90
, 0.25 μg/ml for penicillin-resistant
Streptococcus pneumoniae
). Potent activity was also shown against Gram-negative pathogens (
Haemophilus influenzae
,
Haemophilus parainfluenzae
, and
Moraxella catarrhalis
). Furthermore, wild-type strains of
Enterobacteriaceae
(non-extended-spectrum β-lactamase [ESBL]-producing strains and non-AmpC-hyperproducing strains) were often susceptible to ceftaroline. Continued monitoring through surveillance networks will allow for the assessment of the evolution of resistance as this new cephalosporin is used more broadly to provide clinicians with up-to-date information to assist in antibiotic stewardship and therapeutic decision making.
Pharmacokinetic/Pharmacodynamic Predictors of Clinical Potency for Hepatitis C Virus Nonnucleoside Polymerase and Protease Inhibitors
Authors: Reddy Micaela B. , Morcos Peter N. , Le Pogam Sophie , Ou Ying , Frank Karl , Lave Thierry , Smith Patrick 
Published: April 2012

ABSTRACT

This analysis was conducted to determine whether the hepatitis C virus (HCV) viral kinetics (VK) model can predict viral load (VL) decreases for nonnucleoside polymerase inhibitors (NNPolIs) and protease inhibitors (PIs) after 3-day monotherapy studies of patients infected with genotype 1 chronic HCV. This analysis includes data for 8 NNPolIs and 14 PIs, including VL decreases from 3-day monotherapy, total plasma trough concentrations on day 3 (
C
min
), replicon data (50% effective concentration [EC
50
] and protein-shifted EC
50
[EC
50,PS
]), and for PIs, liver-to-plasma ratios (LPRs) measured
in vivo
in preclinical species. VK model simulations suggested that achieving additional log
10
VL decreases greater than one required 10-fold increases in the
C
min
. NNPolI and PI data further supported this result. The VK model was successfully used to predict VL decreases in 3-day monotherapy for NNPolIs based on the EC
50,PS
and the day 3
C
min
. For PIs, however, predicting VL decreases using the same model and the EC
50,PS
and day 3
C
min
was not successful; a model including LPR values and the EC
50
instead of the EC
50,PS
provided a better prediction of VL decrease. These results are useful for designing phase 1 monotherapy studies for NNPolIs and PIs by clarifying factors driving VL decreases, such as the day 3
C
min
and the EC
50,PS
for NNPolIs or the EC
50
and LPR for PIs. This work provides a framework for understanding the pharmacokinetic/pharmacodynamic relationship for other HCV drug classes. The availability of mechanistic data on processes driving the target concentration, such as liver uptake transporters, should help to improve the predictive power of the approach.
Impact of Two-Component Regulatory Systems PhoP-PhoQ and PmrA-PmrB on Colistin Pharmacodynamics in Pseudomonas aeruginosa
Authors: Ly Neang S. , Yang Jenny , Bulitta Jurgen B. , Tsuji Brian T. 
Published: April 2012

ABSTRACT

The
in vitro
pharmacodynamics of colistin against
Pseudomonas aeruginosa
PAO1 wild-type and isogenic knockout strains of
phoP
and
pmrA
were evaluated. Colistin killing at subinhibitory concentrations was greater against the
phoP
and
pmrA
mutants than the wild type within the first 8 h: the concentration that results in 50% of maximal effect (EC
50
) of the
pmrA
mutant (0.413 mg/liter) was less than that of the wild type (0.718 mg/liter) (
P
< 0.05). An
in vitro
pharmacodynamic model simulating human colistin regimens displayed initial killing followed by regrowth in the
phoP
mutant and gradual regrowth in the
pmrA
mutant and wild type.
Involvement of Mismatch Repair in the Reciprocal Control of Motility and Adherence of Uropathogenic Escherichia coli
Authors: Cooper Lauren A. , Simmons Lyle A. , Mobley Harry L. T. 
Published: April 2012

ABSTRACT

Type 1 fimbriae and flagella, two surface organelles critical for colonization of the urinary tract by uropathogenic
Escherichia coli
(UPEC), mediate opposing virulence objectives. Type 1 fimbriae facilitate adhesion to mucosal cells and promote bacterial persistence in the urinary tract, while flagella propel bacteria through urine and along mucous layers during ascension to the upper urinary tract. Using a transposon screen of the
E. coli
CFT073
fim
locked-ON (L-ON) mutant, a construct that constitutively expresses type 1 fimbriae and represses motility, we identified six mutants that exhibited a partial restoration of motility. Among these six mutated genes was
mutS
, which encodes a component of the methyl-directed mismatch repair (MMR) system. When complemented with
mutS in trans
, motility was again repressed. To determine whether the MMR system, in general, is involved in this reciprocal control, we characterized the effects of gene deletions of other MMR components on UPEC motility. Isogenic deletions of
mutS
,
mutH
, and
mutL
were constructed in both wild-type CFT073 and
fim
L-ON backgrounds. All MMR mutants showed an increase in motility in the wild-type background, and Δ
mutH
and Δ
mutS
mutations increased motility in the
fim
L-ON background. Cochallenge of the wild-type strain with an MMR-defective strain showed a subtle but significant competitive advantage in the bladder and spleen for the MMR mutant using the murine model of ascending urinary tract infection after 48 h. Our findings demonstrate that the MMR system generally affects the reciprocal regulation of motility and adherence and thus could contribute to UPEC pathogenesis during urinary tract infections.
Neutralizing Antibodies Elicited by a Novel Detoxified Pneumolysin Derivative, PlyD1, Provide Protection against Both Pneumococcal Infection and Lung Injury
Authors: Salha Danielle , Szeto Jason , Myers Lisa , Claus Carol , Sheung Anthony , Tang Mei , Ljutic Belma , Hanwell David , Ogilvie Karen , Ming Marin , Messham Benjamin , van den Dobbelsteen Germie , Hopfer Robert , Ochs Martina M. , Gallichan Scott 
Published: April 2012

ABSTRACT

Streptococcus pneumoniae
pneumolysin (PLY) is a virulence factor that causes toxic effects contributing to pneumococcal pneumonia. To date, deriving a PLY candidate vaccine with the appropriate detoxification and immune profile has been challenging. A pneumolysin protein that is appropriately detoxified and that retains its immunogenicity is a desirable vaccine candidate. In this study, we assessed the protective efficacy of our novel PlyD1 detoxified PLY variant and investigated its underlying mechanism of protection. Results have shown that PlyD1 immunization protected mice against lethal intranasal (i.n.) challenge with pneumococci and lung injury mediated by PLY challenge. Protection was associated with PlyD1-specific IgG titers and
in vitro
neutralization titers. Pretreatment of PLY with PlyD1-specific rat polyclonal antiserum prior to i.n. delivery of toxin reduced PLY-mediated lung lesions, interleukin-6 (IL-6) production, and neutrophil infiltration into lungs, indicating that protection from lung lesions induced by PLY is antibody mediated. Preincubation of PLY with a neutralizing monoclonal PLY antibody also specifically reduced the cytotoxic effects of PLY after i.n. inoculation in comparison to nonneutralizing monoclonal antibodies. These results indicate that the induction of neutralizing antibodies against PLY can contribute to protection against bacterial pneumonia by preventing the development of PLY-induced lung lesions and inflammation. Our detoxified PlyD1 antigen elicits such PLY neutralizing antibodies, thus serving as a candidate vaccine antigen for the prevention of pneumococcal pneumonia.
ANRS–COM'TEST: description of a community-based HIV testing intervention in non-medical settings for men who have sex with men
Authors: Champenois Karen , Le Gall Jean-Marie , Jacquemin Cédric , Jean Sophie , Martin Cyril , Rios Laura , Benoit Olivier , Vermoesen Stéphanie , Lert France , Spire Bruno , Yazdanpanah Yazdan 
Published: April 2012

ObjectiveTo describe a community-based HIV testing programme.Design and settingAn intervention of HIV voluntary testing conducted in non-medical settings in four French cities.ParticipantsMen who have sex with men (MSM).InterventionCounselling and rapid HIV testing staffed by trained personnel from an HIV/AIDS community-based organisation.Primary and secondary outcome measuresThe population that has taken hold of the intervention and the satisfaction of participants. Data were collected on demographics, HIV testing history, sexual practices and satisfaction with the testing programme.Results532 MSM were tested between February 2009 and June 2010, of whom 49 (9%) were tested two or more times. 468 MSM (88%) had casual male partners in the previous 6 months, and 152 (35%) reported having unprotected anal intercourse with risky casual partners (HIV infected or HIV serostatus unknown). 159 men (30%) had not been tested in the previous 2 years, and 50 (31%) of whom had unprotected anal intercourse with risky casual partners. Among the 15 patients who tested positive (2.8%), 12 (80%) received confirmation and were linked to care (median CD4 cell count =550/mm3). Satisfaction was high: 92% reported being ‘very satisfied’ with their experience. Steps of counselling and testing procedure were respected by testers and difficulties in handling tests were rare.ConclusionsThis community-based HIV testing programme reached high-risk MSM, of whom a substantial proportion had not been tested lately. This novel service supplements pre-existing HIV testing services and increases access to HIV testing in high-risk groups.
Self-localizing smart camera networks
Authors: Shirmohammadi Babak , Taylor Camillo J. 
Published: April 2012

This article describes a novel approach to localizing networks of embedded cameras and sensors. In this scheme, the cameras and the sensors are equipped with controllable light sources (either visible or infrared), which are used for signaling. Each camera node can then determine automatically the bearing to all of the nodes that are visible from its vantage point. By fusing these measurements with the measurements obtained from onboard accelerometers, the camera nodes are able to determine the relative positions and orientations of other nodes in the network.
The method uses angular measurements derived from images, rather than range measurements derived from time-of-flight or signal attenuation. The scheme can be implemented relatively easily with commonly available components, and it scales well since the localization calculations exploit the sparse structure of the system of measurements. Additionally, the method provides estimates of camera orientation which cannot be determined solely from range measurements.
The localization technology could serve as a basic capability on which higher-level applications could be built. The method could also be used to automatically survey the locations of sensors of interest, to implement distributed surveillance systems, or to analyze the structure of a scene, based on images obtained from multiple registered vantage points. It also provides a mechanism for integrating the imagery obtained from the cameras with the measurements obtained from distributed sensors.