bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting improvement in detection of bacteria in apheresis platelets by maintaining constant component sampling proportion
Authors: Tomasulo Peter A. , Wagner Stephen J. 
Published: July 2012

BACKGROUND: In spite of interventions, approximately 1000 per 1,000,000 platelet (PLT) collections are contaminated with bacteria at collection. The current prestorage culture procedure at some blood centers is to inoculate a fixed volume from the collection bag (4‐8 mL) regardless of collection volume. The sensitivity of early testing varies with the percent of collection volume sampled. We applied the Poisson model to determine whether sampling larger volumes might increase detection at pertinent contamination levels.STUDY DESIGN AND METHODS: The intervention was testing a fixed proportion of the collection volume from single, double, and triple collections. The Poisson model was applied to blood center data to calculate weighted average detection. Model 1 consisted of inoculating 3.2% of the collection volume from single, 1.6% from double, and 1.2% from triple PLT procedures (8 mL in each case). Model 2 consisted of inoculating 3.8% of the collection volume from all PLT procedures. Volume‐related and non–volume‐related contamination mechanisms were evaluated.RESULTS: Testing constant proportions of the collection volume (Model 2) increases percent detection over testing constant volumes (Model 1) (68% vs. 41% detection if contamination is 30 colony‐forming units (CFUs)/collection bag and 17% vs. 9% detection if contamination is 5 CFUs/collection bag). At low levels of contamination (approx. 5 CFUs/bag), the intervention might double the number of contaminated units detected.CONCLUSION: Based on the application of the Poisson model to detection of bacteria in PLT concentrates, inoculating cultures with slightly consistent proportions of the collection volume should lead to a reduction in false negative tests and in the number of contaminated units transfused.
Children younger than 7 years with type 1 diabetes are less physically active than healthy controls
Authors: Sundberg F , Forsander G , Fasth A , Ekelund U 
Published: July 2012

AbstractAim:  To examine if children younger than 7 years with type 1 diabetes are less physically active and spend more time sedentary than healthy children.Methods:  Using a repeated measures case‐control study design, physical activity (PA) was measured by continuous combined accelerometer and heart rate registration for 7 days at two time points during 1 year (autumn and spring). PA data were expressed as time spent sedentary, in moderate and vigorous intensity PA and total PA. Differences between groups and gender were analysed with mixed linear regression models. In this study there were 24 children (12 girls) with type 1 diabetes mellitus and 26 (14 girls) healthy controls, all younger than 7 years at inclusion.Results:  Children with diabetes were less active overall (p = 0.010) and spent 16 min less in moderate‐to‐vigorous PA (p = 0.006). The difference in sedentary time (21 min less) between groups was not significant (p = 0.21). Overall PA (12.1 counts/min per day, p = 0.004) and time in moderate and vigorous PA (16.0 min/day, p = 0.002) was significantly higher in boys than in girls. A significant effect of age was observed.Conclusion:  Physical activity is significantly reduced in young children with type 1 diabetes.
Time course of changes in antioxidant activity of milk from dairy cows fed a trehalose‐supplemented diet
Authors: AOKI Naoto , SATO Kan , KANDA Shuhei , MUKAI Kazuhisa , OBARA Yoshiaki , ITABASHI Hisao 
Published: July 2012

ABSTRACTThis study was to investigate the time course of changes to the antioxidant activity of milk from cows fed a trehalose‐supplemented diet, and to determine possible underlying mechanisms for observed changes. Six Holstein cows were used, and subjected to two experimental feeding periods consisting of a 1% trehalose‐supplemented diet for 10 days, followed by a basal diet only (no trehalose) for 10 days. 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activities in milk were gradually increased during the trehalose supplementation period and were highest at the end of the second period. However, trehalose was not detected in the milk and plasma of dairy cows fed a diet supplemented with trehalose for 10 days, indicating that the increased antioxidant activity in the milk of trehalose‐fed cows is not due to the direct transfer of trehalose to the milk. Plasma DPPH activities exhibited a similar time course to that seen for milk. Relative superoxide dismutase (SOD) activities in the rumen were higher 3 days after the end of trehalose supplementation than at any other time during the experimental periods. These results suggested that the improved antioxidant activity in milk and plasma of cows fed a trehalose‐supplemented diet was due to improved ruminal relative SOD activity.
Comparative
Ex Vivo
Activity of Novel Endoperoxides in Multidrug-Resistant Plasmodium falciparum and P. vivax
Authors: Marfurt Jutta , Chalfein Ferryanto , Prayoga Pak , Wabiser Frans , Wirjanata Grennady , Sebayang Boni , Piera Kim A. , Wittlin Sergio , Haynes Richard K. , Möhrle Jörg J. , Anstey Nicholas M. , Kenangalem Enny , Price Ric N. 
Published: July 2012

ABSTRACT

The declining efficacy of artemisinin derivatives against
Plasmodium falciparum
highlights the urgent need to identify alternative highly potent compounds for the treatment of malaria. In Papua Indonesia, where multidrug resistance has been documented against both
P. falciparum
and
P. vivax
malaria, comparative
ex vivo
antimalarial activity against
Plasmodium
isolates was assessed for the artemisinin derivatives artesunate (AS) and dihydroartemisinin (DHA), the synthetic peroxides OZ277 and OZ439, the semisynthetic 10-alkylaminoartemisinin derivatives artemisone and artemiside, and the conventional antimalarial drugs chloroquine (CQ), amodiaquine (AQ), and piperaquine (PIP).
Ex vivo
drug susceptibility was assessed in 46 field isolates (25
P. falciparum
and 21
P. vivax
). The novel endoperoxide compounds exhibited potent
ex vivo
activity against both species, but significant differences in intrinsic activity were observed. Compared to AS and its active metabolite DHA, all the novel compounds showed lower or equal 50% inhibitory concentrations (IC
50
s) in both species (median IC
50
s between 1.9 and 3.6 nM in
P. falciparum
and 0.7 and 4.6 nM in
P. vivax
). The antiplasmodial activity of novel endoperoxides showed different cross-susceptibility patterns in the two
Plasmodium
species: whereas their
ex vivo
activity correlated positively with CQ, PIP, AS, and DHA in
P. falciparum
, the same was not apparent in
P. vivax
. The current study demonstrates for the first time potent activity of novel endoperoxides against drug-resistant
P. vivax
. The high activity against drug-resistant strains of both
Plasmodium
species confirms these compounds to be promising candidates for future artemisinin-based combination therapy (ACT) regimens in regions of coendemicity.
Therapeutic Drug Monitoring of Posaconazole in Allogeneic Hematopoietic Stem Cell Transplantation Patients Who Develop Gastrointestinal Graft-versus-Host Disease
Authors: Tonini J. , Thiébaut A. , Jourdil J. F. , Berruyer A. S. , Bulabois C. E. , Cahn J. Y. , Stanke-Labesque F. 
Published: July 2012

ABSTRACT

Posaconazole (PCZ) is the latest triazole antifungal agent that has been approved for prophylaxis of invasive aspergillosis in high-risk immunocompromised patients, such as allogeneic hematopoietic stem cell transplantation patients, who develop graft-versus-host disease (GVHD). PCZ has high interindividual variability with regard to its plasma drug trough concentrations (
C
min
). Moreover, the concentration-efficiency relationship remains to be better characterized in prophylaxis. To determine the variability factors in plasma drug concentrations, the PCZ
C
min
and clinical parameters (localization of GVHD, presence of diarrhea, and diagnosis of invasive aspergillosis) were collected retrospectively in 29 consecutive allogeneic hematopoietic stem cell transplantation patients who developed GVHD and were receiving prophylactic PCZ (200 mg, 3 times/day, for ≥7 days). Blood samples were analyzed at steady state to determine the PCZ
C
min
by liquid chromatography-tandem mass spectrometry. The average PCZ
C
min
was 1.28 ± 0.82 mg/liter (mean ± standard deviation;
n
= 292 dosages), with an intraindividual variability of 49% and an interindividual variability of 64%. Twenty percent of
C
min
s were below 0.7 mg/liter, which is considered the threshold of efficacy by the Food and Drug Administration. The patients who had gastrointestinal (GI) GVHD experienced a 24% reduction in the posaconazole
C
min
, compared with those with other localizations of GVHD. This decrease reached 33% when patients presented with diarrhea due to GI GVHD or an infectious etiology. PCZ
C
min
s were 26% lower when invasive aspergillosis was declared. These data demonstrate that GI disturbances affect drug concentrations. Thus, therapeutic monitoring of PCZ can be used to detect low drug concentrations, possibly resulting in a lack of efficacy of invasive aspergillosis prophylaxis.
Modulation of Toxin Production by the Flagellar Regulon in Clostridium difficile
Authors: Aubry Annie , Hussack Greg , Chen Wangxue , KuoLee Rhonda , Twine Susan M. , Fulton Kelly M. , Foote Simon , Carrillo Catherine D. , Tanha Jamshid , Logan Susan M. 
Published: July 2012

ABSTRACT

We show in this study that toxin production in
Clostridium difficile
is altered in cells which can no longer form flagellar filaments. The impact of inactivation of
fliC
,
CD0240
,
fliF
,
fliG
,
fliM
, and
flhB-fliR
flagellar genes upon toxin levels in culture supernatants was assessed using cell-based cytotoxicity assay, proteomics, immunoassay, and immunoblotting approaches. Each of these showed that toxin levels in supernatants were significantly increased in a
fliC
mutant compared to that in the
C. difficile
630 parent strain. In contrast, the toxin levels in supernatants secreted from other flagellar mutants were significantly reduced compared with that in the parental
C. difficile
630 strain. Transcriptional analysis of the pathogenicity locus genes (
tcdR
,
tcdB
,
tcdE
, and
tcdA
) revealed a significant increase of all four genes in the
fliC
mutant strain, while transcription of all four genes was significantly reduced in
fliM
,
fliF
,
fliG
, and
flhB-fliR
mutants. These results demonstrate that toxin transcription in
C. difficile
is modulated by the flagellar regulon. More significantly, mutant strains showed a corresponding change in virulence compared to the 630 parent strain when tested in a hamster model of
C. difficile
infection. This is the first demonstration of differential flagellum-related transcriptional regulation of toxin production in
C. difficile
and provides evidence for elaborate regulatory networks for virulence genes in
C. difficile
.
Role of a New Intimin/Invasin-Like Protein in Yersinia pestis Virulence
Authors: Seo Keun Seok , Kim Jong Wan , Park Joo Youn , Viall Austin K. , Minnich Scott S. , Rohde Harold N. , Schnider Darren R. , Lim Seung Yong , Hong Joon Bae , Hinnebusch B. Joseph , O'Loughlin Jason L. , Deobald Claudia F. , Bohach Gregory A. , Hovde Carolyn J. , Minnich Scott A. 
Published: July 2012

ABSTRACT

A comprehensive Tn
phoA
mutant library was constructed in
Yersinia pestis
KIM6 to identify surface proteins involved in
Y. pestis
host cell invasion and bacterial virulence. Insertion site analysis of the library repeatedly identified a 9,042-bp chromosomal gene (YPO3944), intimin/invasin-like protein (Ilp), similar to the Gram-negative intimin/invasin family of surface proteins. Deletion mutants of
ilp
were generated in
Y. pestis
strains KIM5(pCD1
+
) Pgm
−
(pigmentation negative)/, KIM6(pCD1
−
) Pgm
+
, and CO92. Comparative analyses were done with the deletions and the parental wild type for bacterial adhesion to and internalization by HEp-2 cells
in vitro
, infectivity and maintenance in the flea vector, and lethality in murine models of systemic and pneumonic plague. Deletion of
ilp
had no effect on bacterial blockage of flea blood feeding or colonization. The
Y. pestis
KIM5 Δ
ilp
strain had reduced adhesion to and internalization by HEp-2 cells compared to the parental wild-type strain (
P
< 0.05). Following intravenous challenge with
Y. pestis
KIM5 Δ
ilp
, mice had a delayed time to death and reduced dissemination to the lungs, livers, and kidneys as monitored by
in vivo
imaging using a
lux
reporter system (
in vivo
imaging system [IVIS]) and bacterial counts. Intranasal challenge in mice with
Y. pestis
CO92 Δ
ilp
had a 55-fold increase in the 50% lethal dose ([LD
50
] 1.64 × 10
4
CFU) compared to the parental wild-type strain LD
50
(2.98 × 10
2
CFU). These findings identified Ilp as a novel virulence factor of
Y. pestis
.
Distribution of white spruce lateral fine roots as affected by the presence of trembling aspen: root mapping using simple sequence repeat DNA profiling
Authors: Lawrence Derek Joseph , Luckai N. , Meyer W.L. , Shahi C. , Fazekas A.J. , Kesanakurti P. , Newmaster S. 
Published: August 2012

Mixedwood forests of white spruce ( Picea glauca (Moench) Voss) and trembling aspen ( Populus tremuloides Michx.) may possess ecological advantages over monospecific white spruce stands. Belowground competition may be reduced through vertically stratified roots; facilitation of growth may occur in upper soil layers through nutrient-rich trembling aspen litterfall. These effects may incentivize white spruce to preferentially exploit upper soil layers in mixedwood stands, resulting in wider root systems. This research contrasted white spruce fine root (diameter <2 mm) distributions in organic layers of white spruce and mixedwood stands. Research occurred at the Fallingsnow Ecosystem Project site in northwestern Ontario. Eighteen plots represented mixedwood and pure white spruce stands. Trees were mapped; foliage and root samples were collected. Roots were separated by species and scanned to determine length. Simple sequence repeat DNA profiles were determined for all white spruce trees and for 45 white spruce root fragments per plot. Root and tree DNA profiles were matched; corresponding distances were calculated. Most (80%) root fragments were within 3.2 m of tree stems. Root prevalence decreased rapidly with distance. Organic layer pH was significantly less acidic in mixedwood plots, but only in one block. A subtle significant trend towards wider root distributions occurred in mixedwood stands.
Variation in mass and nutrient concentration of leaf litter across years and sites in a northern hardwood forest
Authors: Yanai Ruth D. , Arthur Mary A. , Acker Marty , Levine Carrie R. , Park Byung Bae 
Published: August 2012

Leaf litterfall represents an important nutrient flux in forests, but separating leaves by species and collecting fresh litter annually for nutrient analysis is time-consuming and expensive. To quantify the sources of variation in litterfall nutrient estimates and guide optimal allocation of research effort, we analyzed nutrient concentration (5 years) and mass (6 years) of leaf litter for nine tree species in 13 northern hardwood sites. Coefficients of variation (CVs) in nutrient concentration were higher across sites than over time within sites for most elements; phosphorus was especially variable across sites (56% CV). Thus, to estimate litterfall nutrient fluxes accurately in forests of this type, nutrient analyses should be site-specific as well as species-specific but may not need to be repeated annually (CVs over time averaged 17% for calcium, 21% for magnesium, 28% for potassium, and 32% for phosphorus concentration). Total leaf litterfall mass varied considerably from year to year, ranging from 234 to 370 g·m–2 averaged over 13 sites. We recommend that litter collectors be elevated above the ground to avoid oversampling during extreme wind events. Use of species-specific allometric equations, or even basal area, to estimate the species composition of total litter mass may obviate the need to sort litter by species.
Differential persistence of blue ash and white ash following emerald ash borer invasion
Authors: Tanis Sara R. , McCullough Deborah G. 
Published: August 2012

Catastrophic mortality of North American ash ( Fraxinus spp.) caused by Agrilus planipennis Fairmaire has been attributed to the lack of coevolved resistance between native ash species and this Asian invader. Although A. planipennis host preference or tree resistance can vary, all North American ash species are presumably highly vulnerable to A. planipennis. We inventoried live and dead blue ash ( Fraxinus quadrangulata Michx.) and white ash ( Fraxinus americana L.) in two southeastern Michigan woodlots several years after the A. planipennis invasion to assess their survival. Agrilus planipennis populations in this area peaked in approximately 2005, and the region is now characterized by nearly complete ash mortality. At the Plymouth site, 71% of the original 380 blue ash were alive, whereas only 29 saplings of the original 187 white ash were alive. At the Superior Township site, 63% of the original 210 blue ash were living, whereas all 125 white ash were dead. More than 80% of the blue ash had evidence of previous A. planipennis colonization, but 87% appeared healthy in 2011. Tree diameter did not consistently affect survival, and live and dead trees of both species were distributed across sites, indicating that differential survival was not attributable to localized conditions.
Do small mammals prey upon an invasive ectoparasite of cervids?
Authors: Kaunisto Sirpa , Kortet Raine , Härkönen Sauli , Kaitala Arja , Laaksonen Sauli , Ylönen Hannu 
Published: August 2012

Predation is often considered an important factor for population regulation and in some cases for the invasion success of prey. Small mammalian predation may be a major force in the population regulation of many ground-dwelling invertebrate species. The deer ked ( Lipoptena cervi (L., 1758)) is an ectoparasitic fly of cervids. The species has a large distribution area and it has relatively rapidly spread in northern Europe during the previous four decades. The factors possibly regulating the distribution and invasion of this fly are poorly known. During the off-host stage of several months, pupae of deer ked are likely exposed to many ground-dwelling predators. To study whether small mammals would feed on deer keds, we conducted experiments by serving pupae of deer ked to wild-captured common shrews ( Sorex araneus L., 1758), bank voles ( Myodes glareolus (Schreber, 1780)), field voles ( Microtus agrestis (L., 1761)), and semi-wild bank voles, and assessed pupal survival. As a control, we provided alternative food including common nutrients used by small mammals in their natural habitats. The results show that variable amounts of pupae of deer ked are consumed by all small-mammal species studied. Surprisingly, insectivorous and most of the time food-constrained shrews consumed less pupae than granivorous–herbivorous voles.
Single-trial EEG classification of artifacts in videos
Authors: Mustafa Maryam , Guthe Stefan , Magnor Marcus 
Published: July 2012

In this article we use an ElectroEncephaloGraph (EEG) to explore the perception of artifacts that typically appear during rendering and determine the perceptual quality of a sequence of images. Although there is an emerging interest in using an EEG for image quality assessment, one of the main impediments to the use of an EEG is the very low Signal-to-Noise Ratio (SNR) which makes it exceedingly difficult to distinguish neural responses from noise. Traditionally, event-related potentials have been used for analysis of EEG data. However, they rely on averaging and so require a large number of participants and trials to get meaningful data. Also, due the the low SNR ERP's are not suited for single-trial classification.
We propose a novel wavelet-based approach for evaluating EEG signals which allows us to predict the perceived image quality from only a single trial. Our wavelet-based algorithm is able to filter the EEG data and remove noise, eliminating the need for many participants or many trials. With this approach it is possible to use data from only 10 electrode channels for single-trial classification and predict the presence of an artifact with an accuracy of 85%. We also show that it is possible to differentiate and classify a trial based on the exact type of artifact viewed. Our work is particularly useful for understanding how the human visual system responds to different types of degradations in images and videos. An understanding of the perception of typical image-based rendering artifacts forms the basis for the optimization of rendering and masking algorithms.
Translation Regulation as a Therapeutic Target in Cancer
Authors: Grzmil Michal , Hemmings Brian A. 
Published: August 2012

Abstract
Protein synthesis is a vital cellular process that regulates growth and metabolism. It is controlled via signaling networks in response to environmental changes, including the presence of nutrients, mitogens, or starvation. The phosphorylation state of proteins involved in translation initiation is a limiting factor that regulates the formation or activity of translational complexes. In cancer cells, hyperactivated signaling pathways influence translation, allowing uncontrolled growth and survival. In addition, several components of translation initiation have been found to be mutated, posttranslationally modified, or differentially expressed, and some act as oncogenes in cancer cells. Translational alterations can increase the overall rate of protein synthesis as well as activate regulatory mechanisms leading to the translation of specific messenger RNAs for proteins that promote cancer progression and survival. Many recent studies investigating such mechanisms have produced ideas for therapeutic intervention. This review describes altered mechanisms of protein synthesis in human cancers and discusses therapeutic approaches based on the targeting of translation. Cancer Res; 72(16); 3891–900. ©2012 AACR.