bluuebunny/crossref_metadata_2025 huggingface dataset:
Blast cell deficiency of CD11a as a marker of acute megakaryoblastic leukemia and transient myeloproliferative disease in children with and without Down syndrome
Authors: Boztug Heidrun , Schumich Angela , Pötschger Ulrike , Mühlegger Nora , Kolenova Alexandra , Reinhardt Katarina , Dworzak Michael
Published: March 2013

Background

The classification of acute myeloid leukemia (AML) FAB subtype M7 relies on immunophenotypic assessment. CD41 is expressed throughout all stages of maturation of megakaryocytes and has therefore been described as a specific blast cell marker in AML M7 as well as in transient myeloproliferative disease (TMD) of patients with Down syndrome (DS). However, technical difficulties underlie the need for new markers for these entities.

Methods

We evaluated the expression of human lymphocyte function‐associated antigen 1 (CD11a) in a large cohort of pediatric AML and TMD patients (n = 91) of the Austrian AML‐BFM 98 and 2004 studies.

Results

We found a consistent deficiency of CD11a as assessed by mean fluorescence intensity in all patients with non‐DS AML M7 (n = 8) and M6 (n = 1), all cases of classical DS‐AML (n = 12) as well as TMD (n = 15) that was statistically significant in comparison to non‐DS AML M0‐M5 patients (n = 55; P < 0.001, sensitivity 100%). Only three of 55 Non‐DS M0‐5 patients were CD11a deficient (specificity 95%). Monocytic leukemias (M4/5) and normal monocytes typically showed a high CD11a expression, FAB types M1/2 and normal neutrophils an intermediate expression level, while all M3 leukemias were rather low in CD11a expression.

Conclusions

We conclude, that deficiency of CD11a expression should be added to the diagnostic criteria of AML‐M7, classical DS‐AML and TMD. © 2013 International Clinical Cytometry Society
Effects of pulse period of near‐field ground motions on the seismic demands of soil–MDOF structure systems using mathematical pulse models
Authors: Khoshnoudian Faramarz , Ahmadi Ehsan
Published: March 2013

In this paper, the effects of pulse period associated with near‐field ground motions on the seismic demands of soil–MDOF structure systems are investigated by using mathematical pulse models. Three non‐dimensional parameters are employed as the crucial parameters, which govern the responses of soil–structure systems: (1) non‐dimensional frequency as the structure‐to‐soil stiffness ratio; (2) aspect ratio of the superstructure; and (3) structural target ductility ratio. The soil beneath the superstructure is simulated on the basis of the Cone model concept. The superstructure is modeled as a nonlinear shear building. Interstory drift ratio is selected as the main engineering demand parameter for soil–structure systems. It is demonstrated that the contribution of higher modes to the response of soil–structure system depends on the pulse‐to‐interacting system period ratio instead of pulse‐to‐fixed‐base structure period ratio. Furthermore, results of the MDOF superstructures demonstrate that increasing structural target ductility ratio results in the first‐mode domination for both fixed‐base structure and soil–structure system. Additionally, increasing non‐dimensional frequency and aspect ratio of the superstructure respectively decrease and increase the structural responses. Moreover, comparison of the equivalent soil–SDOF structure system and the soil–MDOF structure system elucidates that higher‐mode effects are more significant, when soil–structure interaction is taken into account. In general, the effects of fling step and forward directivity pulses on activating higher modes of the superstructure are more sever in soil–structure systems, and in addition, the influences of forward directivity pulses are more considerable than fling step ones. Copyright © 2013 John Wiley & Sons, Ltd.
Probing deep weathering in the Shale Hills Critical Zone Observatory, Pennsylvania (USA): the hypothesis of nested chemical reaction fronts in the subsurface
Authors: Brantley Susan L. , Holleran Molly E. , Jin Lixin , Bazilevskaya Ekaterina
Published: March 2013

Weathering is both an acid‐base and a redox reaction in which rocks are titrated by meteoric carbon dioxide (CO2) and oxygen (O2). In general, the depths of these weathering reactions are unknown. To determine such depths, cuttings of Rose Hill shale were investigated from one borehole from the ridge and four boreholes from the valley at the Susquehanna Shale Hills Observatory (SSHO). Pyrite concentrations are insignificant to depths of 23 m under the ridge and 8–9 m under the valley. Likewise, carbonate concentrations are insignificant to 22 and 2 m, respectively. In addition, a 5–6 m‐thick fractured layer directly beneath the land surface shows evidence for loss of illite, chlorite, and feldspar. Under the valley, secondary carbonates may have precipited.

The limited number of boreholes and the tight folding make it impossible to prove that depth variations result from weathering instead of chemical heterogeneity within the parent shale. However, carbonate depletion coincides with the winter water table observed at ~20 m (ridge) and ~2 m depth (valley). It would be fortuitous if carbonate‐containing strata are found under ridge and valley only beneath the water table. Furthermore, pyrite and carbonate react quickly and many deep reaction fronts for these minerals are described in the literature. We propose that deep transport of O2 initiates weathering at SSHO and many other localities because pyrite commonly oxidizes autocatalytically to acidify porewaters and open porosity. According to this hypothesis, the mineral distributions at SSHO are nested reaction fronts that overprint protolith stratigraphy. The fronts are hypothesized to lie subparallel to the land surface because O2 diffuses to the water table and causes oxidative dissolution of pyrite. Pyrite‐derived sulfuric acid (H2SO4) plus CO2 also dissolve carbonates above the water table. To understand how reaction fronts record long‐term coupling between erosion and weathering will require intensive mapping of the subsurface. Copyright © 2013 John Wiley & Sons, Ltd.
Reproductive impacts of tributyltin (TBT) and triphenyltin (TPT) in the hermaphroditic freshwater gastropod Lymnaea stagnalis
Authors: Giusti Arnaud , Barsi Alpar , Dugué Maël , Collinet Marc , Thomé Jean-Pierre , Joaquim-Justo Célia , Roig Benoit , Lagadic Laurent , Ducrot Virginie
Published: March 2013

Tributyltin (TBT) and triphenyltin (TPT) are emblematic endocrine disruptors, which have been mostly studied in gonochoric prosobranchs. Although both compounds can simultaneously occur in the environment, they have mainly been tested separately for their effects on snail reproduction. Because large discrepancies in experimental conditions occurred in these tests, the present study aimed to compare the relative toxicity of TBT and TPT under similar laboratory conditions in the range of 0 ng Sn/L to 600 ng Sn/L. Tests were performed on the simultaneous hermaphrodite Lymnaea stagnalis, a freshwater snail in which effects of TPT were unknown. Survival, shell length, and reproduction were monitored in a 21-d semistatic test. Frequency of abnormal eggs was assessed as an additional endpoint. Triphenyltin hampered survival while TBT did not. Major effects on shell solidity and reproduction were observed for both compounds, reproductive outputs being more severely hampered by TBT than by TPT. Considering the frequency of abnormal eggs allowed increasing test sensitivity, because snail responses to TBT could be detected at concentrations as low as 19 ng Sn/L. However, the putative mode of action of the 2 compounds could not be deduced from the structure of the molecules or from the response of apical endpoints. Sensitivity of L. stagnalis to TBT and TPT was compared with the sensitivity of prosobranch mollusks with different habitats and different reproductive strategies. Environ Toxicol Chem 2013;32:1552–1560. © 2013 SETAC
Evaluation of PCB bioaccumulation by Lumbriculus variegatus in field-collected sediments
Authors: Burkhard Lawrence P. , Mount David R. , Highland Terry L. , Hockett J. Russell , Norberg-King Teresa , Billa Nanditha , Hawthorne Steven B. , Miller David J. , Grabanski Carol B.
Published: March 2013

Review of data from several contaminated sediment sites suggested that biota-sediment accumulation factors (BSAFs) declined with increasing contaminant concentrations in the sediment. To evaluate the consistency and possible causes of this behavior, polychlorinated biphenyl (PCB)–contaminated sediment samples from the Hudson, Grasse, and Fox River Superfund sites were used in sediment bioaccumulation tests with the freshwater oligochaete, Lumbriculus variegatus, with PCB concentrations in interstitial water (IW) quantified using polyoxymethylene passive samplers. Measured BSAFs tended to decrease with increasing PCB concentration in sediment, especially for the more highly chlorinated congeners. Measures of partitioning between sediment, IW, and oligochaetes showed that measured sediment–IW partition coefficients (KTOC) tended to increase slightly with increasing sediment contamination, whereas the ratio of tissue PCB to IW PCB tended to decrease with increasing concentration in IW. Variation in accumulation among sediments was clearly influenced by bioavailability, as reflected by IW measurements, although the specific cause of varying KTOC was not clear. Calculated partitioning between IW and organism lipid (Klipid) indicated that accumulation was generally 5 to 10-fold higher than would be predicted if Klipid was approximately equal to the n-octanol–water partition coefficient (KOW). While affirming previous observations of decreasing BSAFs with increasing PCB contamination, the relatively shallow slope of the observed relationship in the current data may suggest that this concentration dependence is not a major uncertainty in sediment risk assessment, particularly if measurements of PCBs in IW are incorporated. Environ Toxicol Chem 2013;32:1495–1503. © 2013 SETAC
Complexes of the antimicrobial ciprofloxacin with soil, peat, and aquatic humic substances
Authors: Aristilde Ludmilla , Sposito Garrison
Published: March 2013

Natural organic matter (NOM) is implicated in the binding of antibiotics by particles in soils and waters. The authors' previous computational study revealed structural rearrangement of both hydrophilic and hydrophobic moieties of NOM to favor H-bonding and other intermolecular interactions, as well as both competition with ion-exchange reactions and bridging interactions by NOM-bound divalent cations. The importance of these interactions was investigated using fluorescence-quenching spectroscopy to study the adsorption of ciprofloxacin (Cipro), a fluoroquinolone antibiotic, on 4 reference humic substances (HSs): Elliott soil humic acid (HA), Pahokee peat HA, and Suwannee river HA and fulvic acid. A simple affinity spectrum HS model was developed to characterize the cation-exchange capacity and the amount of H-bond donor moieties as a function of pH. The adsorption results stress the influence of both pH conditions and the type of HS: both soil HA and peat HA exhibited up to 3 times higher sorption capacity than the aquatic HS at pH ≥ 6, normalizing to the aromatic C content accounted for the differences among the terrestrial HS, and increasing the concentration of divalent cations led to a decrease in adsorption on aquatic HA but not on soil HA. In addition, the pH-dependent speciation models of the Cipro–HS complexes illustrate an increase in complexation due to an increase in deprotonation of HS ligands with increasing pH and, at circumneutral and alkaline pH, enhanced complexation of zwitterionic Cipro only in the presence of soil HA and peat HA. The findings of the present study imply that, in addition to electrostatic interactions, van der Waals interactions as facilitated by aromatic structures and H-bond donating moieties in terrestrial HS may facilitate a favorable binding environment. Environ Toxicol Chem 2013;32:1467–1478. © 2013 SETAC
European studies on the prevalence of dementia in the elderly: time for a step towards a methodological consensus
Authors: Misiak Blazej , Cialkowska‐Kuzminska Magdalena , Frydecka Dorota , Chladzinska‐Kiejna Sylwia , Kiejna Andrzej
Published: March 2013

Objective

The aim of this study was to discuss methodological limitations in studies on the prevalence of dementia across European countries with particular attention to post‐EURODEM studies.

Methods

Two people independently focused on an iterative literature search for studies published in the years 2000–2012 using the following keywords: ‘dementia’, ‘Alzheimer’, ‘incidence’, ‘prevalence’ that were cross‐linked with names of European countries. After that, the results obtained were compared and publications in English were included in a subsequent analysis.

Results

We included 26 studies published in the years 2000–2012. The majority of epidemiological studies come from Spain and Italy. The past decade has not provided prevalence rates from a considerable number of countries. There is also a lack of nationwide surveys on the prevalence of dementia. Predominantly, epidemiological studies on the prevalence of dementia follow a two‐stage approach that consists of a screening phase and a subsequent confirmation of dementia. However, several differences, particularly with regard to the neuropsychological instruments used, still exist and contribute to inconsistent prevalence rates.

Conclusions

Although the EURODEM study was a milestone in the epidemiology of dementia in Europe and provided several future directions for research, methodological limitations are apparent in a number of European studies on the prevalence of dementia and require particular attention. In particular, a variety of diagnostic instruments requires unification for future studies. On the other hand, given the lack of epidemiological studies from a number of countries and the increasing prevalence of dementia, the need for population‐based surveys should be emphasized. Copyright © 2013 John Wiley & Sons, Ltd.
Lower tropospheric ozone at northern midlatitudes: Changing seasonal cycle
Authors: Parrish D. D. , Law K. S. , Staehelin J. , Derwent R. , Cooper O. R. , Tanimoto H. , Volz‐Thomas A. , Gilge S. , Scheel H.‐E. , Steinbacher M. , Chan E.
Published: March 2013

At northern midlatitudes the abundance of tropospheric O3 has increased by a factor of approximately 2 since the 1950s. The cause of this increase is generally attributed to increasing anthropogenic precursor emissions, but present chemical and transport models cannot quantitatively reproduce its magnitude. Here we show another manifestation of changes in O3 abundance—a shift of the seasonal cycle at northern midlatitudes so that the observed peak concentrations now appear earlier in the year than in previous decades. The rate of this shift has been 3 to 6 days per decade since the 1970s. We examine possible reasons to explain this shift and suggest it is due to changes in atmospheric transport patterns combined with spatial and temporal changes in emissions. Detailed modeling is necessary to test these hypotheses; this investigation will provide useful guidance for improving global chemistry‐climate models and stringent tests of the model results.
Structural brain network imaging shows expanding disconnection of the motor system in amyotrophic lateral sclerosis
Authors: Verstraete Esther , Veldink Jan H. , van den Berg Leonard H. , van den Heuvel Martijn P.
Published: March 2013

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease, which primarily targets the motor system. The structural integrity of the motor network and the way it is embedded in the overall brain network is essential for motor functioning. We studied the longitudinal effects of ALS on the brain network using diffusion tensor imaging and questioned whether over time an increasing number of connections become involved or whether there is progressive impairment of a limited number of connections. The brain network was reconstructed based on “whole brain” diffusion tensor imaging data. We examined: (1) network integrity in 24 patients with ALS at baseline (T = 1) and at a more advanced stage of the disease (T = 2; interval 5.5 months) compared with a group of healthy controls and (2) progressive brain network impairment comparing patients at two time‐points in a paired‐analysis. These analyses demonstrated an expanding subnetwork of affected brain connections over time with a central role for the primary motor regions (P‐values T = 1 0.003; T = 2 0.001). Loss of structural connectivity mainly propagated to frontal and parietal brain regions at T = 2 compared with T = 1. No progressive impairment of the initially affected (motor) connections could be detected. The main finding of this study is an increasing loss of network structure in patients with ALS. In contrast to the theory of ALS solely affecting a fixed set of primary motor connections, our findings show that the network of impaired connectivity is expanding over time. These results are in support of disease spread along structural brain connections. Hum Brain Mapp 35:1351–1361, 2014. © 2013 Wiley‐Periodicals, Inc.
Slow biasing of processing resources in early visual cortex is preceded by emotional cue extraction in emotion–attention competition
Authors: Schönwald Liane I. , Müller Matthias M.
Published: March 2013

In our previous studies on competition for attentional processing resources in early visual cortex between a foreground task and distracting emotional background images we found that emotional background images withdraw attentional resources from the foreground task after about 400 ms. Costs in behavioral data and a significant reduction of the steady state visual evoked potential (SSVEP) amplitude that was elicited by the foreground task lasted for several hundred milliseconds. We speculated that the differential effect in SSVEP amplitudes is preceded by the extraction of the emotional cue. Event related potential (ERP) studies to emotional and neutral complex images identified an early posterior negativity (EPN) as a robust neural signature of emotional cue extraction. The late positive potential (LPP) was related to in‐depth processing of the emotional image. We extracted ERPs that were evoked by the onset of background images concurrently with the SSVEP that was elicited by the foreground task. Emotional compared to neutral background pictures evoked a more negative EPN at about 190 ms and a more positive LPP at about 700 ms after image onset. SSVEP amplitudes became significantly smaller with emotional background images after about 400 ms lasting for several hundred ms. Interestingly, we found no significant correlations between the three components, indicating that they act independently. Source localizations resulted in nonoverlapping cortical generators. Results suggest a cascade of perceptual processes: Extraction of the emotional cue preceded biasing of attentional resources away from the foreground task towards the emotional image for an evaluation of the picture content. Hum Brain Mapp 35:1477–1490, 2014. © 2013 Wiley Periodicals, Inc.
Assessing crop yield and crop water productivity and optimizing irrigation scheduling of winter wheat and summer maize in the Haihe plain using SWAT model
Authors: Sun Chen , Ren Li
Published: March 2013

Haihe plain is an important food production area in China, facing an increasing water shortage. The water used for agriculture accounts for about 70% of total water resources. Thus, it is critical to optimize the irrigation scheduling for saving water and increasing crop water productivity (CWP). This study first simulated crop yield and CWP for winter wheat and summer maize in historical scenario during 1961–2005 for Haihe plain using previously well‐established Soil and Water Assessment Tool model. Then, scenarios under historical irrigation (scenario 1) and sufficient irrigation (scenario 2) were, respectively, simulated both with sufficient fertilizer. The crop yield in scenario 2 was considered as the potential crop yield. The optimal irrigation scheduling with sufficient fertilizer (scenario 3) was explored by iteratively adjusting irrigation scheduling based on the scenario 1 and previous studies related to water stress on crop growth. Results showed that net irrigation amount was, respectively, reduced 23.1% and 18.8% in scenario 3 for winter wheat and summer maize when compared with scenario 1. The CWP was 12.1% and 8.2% higher with very slight change of crop yield. Using optimal irrigation scheduling could save 8.8 × 108 m3 irrigation water and reduce about 16.3% groundwater over‐exploitation in winter wheat growth period. The corresponding yield was 18.5% and 12.9% less than potential yield for winter wheat and summer maize but using less irrigation water. Therefore, it could be considered that the optimal irrigation was reasonable, which provided beneficial suggestions for increasing efficiency of agricultural water use with sustainable crop yield in Haihe plain. Copyright © 2013 John Wiley & Sons, Ltd.
Assessment of a seasonal calibration technique using multiple objectives in rainfall–runoff analysis
Authors: Kim H.S. , Lee S.
Published: March 2013

The hydrological response characteristics for the catchments in the Republic of Korea are related to a strong seasonality in the rainfall and streamflow distributions with distinct wet and dry seasons. This study aims to improve a model's ability to predict streamflows by minimizing information loss from the available data during the calibration processes. This study assesses calibration techniques incorporating a multi‐objective approach and seasonal calibration. The lumped conceptual rainfall–runoff model IHACRES was applied to selected catchments in Korea. The model was calibrated based on three different methods: the classical approach using a single performance statistic (the single‐objective method), the multi‐objective approach (the multi‐objective method (I)) and the combined approach incorporating multi‐objective and seasonal calibrations (the multi‐objective method (II)). In the multi‐objective approach, the ‘best fit’ models in the calibration period were selected by considering the trade‐offs among multiple statistics. During seasonal calibration, the calibration period was divided into four seasons to investigate whether these calibrated models can improve the model performance with regards to seasonal climate, rainfall and streamflow distributions. The adequacy of the three different calibration methods was assessed through comparison of the variability of model performance in high and low flows and water balance for the entire period and for each seasonal period. The multi‐objective methods yielded more accurate and consistent predictions for high and low flows and water balance simultaneously, compared to the single‐objective method. In particular, the multi‐objective method (II) produces the best modelling capacity to capture the non‐stationary nature of the hydrological response under different climate conditions. The pattern of improvement with the multi‐objective method (II) was generally consistent through the seasons, with the exception of the winter period in the regions partially affected by snow. This exception is due to a potential limitation of the IHACRES model in reflecting the impact of snow on the catchment hydrology. Copyright © 2013 John Wiley & Sons, Ltd.
Modelling incoming radiation on a linear disturbance and its impact on the ground thermal regime in discontinuous permafrost
Authors: Williams T. J. , Quinton W. L.
Published: March 2013

Human‐induced disturbances and climate‐driven warming have resulted in unprecedented permafrost thaw in the zone of discontinuous permafrost. In a peatland environment south of Fort Simpson, NWT, we study the contribution of increases in incoming radiation to the ground surface, caused by removal of the tree canopy along linear disturbances, to changes in the ground thermal regime. A physically based understanding of thaw processes along linear disturbances is required in order to better understand the slow recovery of lines in this environment and to be able to efficiently reduce this impact during future resource exploration. The impact of increases in incoming radiation are examined through the development of a model (seismic incoming radiation model) to quantify these inputs, which are then used to drive the one‐dimensional coupled atmospheric‐surface‐subsurface model COUP. Results of this study show that incoming radiation (shortwave + longwave) is increased by up to 11% in a typical cutline compared to an undisturbed canopy. Relative to potential changes in near‐surface soil moisture, these increases in radiation do not appear to be an important control of permafrost thaw along linear disturbances. Field observations confirm that increased permafrost thaw on disturbances often occur irrespective of variations in incoming radiation. Copyright © 2013 John Wiley & Sons, Ltd.
Co‐registered pulse‐echo/photoacoustic transvaginal probe for real time imaging of ovarian tissue
Authors: Kumavor Patrick D. , Alqasemi Umar , Tavakoli Behnoosh , Li Hai , Yang Yi , Sun Xiaoguang , Warych Edward , Zhu Quing
Published: March 2013

We present the design and construction of a prototype imaging probe capable of co‐registered pulse‐echo ultrasound and photoacoustic (optoacoustic) imaging in real time. The probe consists of 36 fibers of 200 micron core diameter each that are distributed around a commercial transvaginal ultrasound transducer, and housed in a protective shield. Its performance was demonstrated by two sets of experiments. The first set involved imaging of blood flowing through a tube mimicking a blood vessel, the second set involved imaging of human ovaries ex vivo. The results suggest that the system along with the probe has great potential for imaging and characterizing of ovarian tissue in vivo. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sensitivity enhanced nanothermal sensors for photoacoustic temperature mapping
Authors: Chen Yun‐Sheng , Frey Wolfgang , Walker Charles , Aglyamov Salavat , Emelianov Stanislav
Published: March 2013

Photoacoustic imaging can be used to guide and validate the therapeutic outcome of nanoparticle‐mediated photothermal therapy through its ability to visualize the delivery of nanoparticle contrast agents, image the temperature distribution inside living tissue, and confirm tissue coagulation. In this image‐guided process, temperature mapping plays a critical role for thermal dosage control. Therefore, developing a sensitive and accurate photoacoustic technique to quantitatively measure the temperature distribution during thermal therapy is essential. In this study, we investigated and demonstrated that silica‐coated gold nanorods, can provide a multi‐fold improvement in sensitivity of the photoacoustic temperature mapping compared to gold nanorods without silica coating, and serve as a nanothermal sensor to accurately and quantitatively visualize temperature distributions during photothermal therapy. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Morphological variation in the appendicular skeleton of atlantic forest sigmodontine rodents
Authors: Coutinho Ludmilla Carvalho , de Oliveira, João Alves , Pessôa Leila Maria
Published: March 2013

Rodents of the subfamily Sigmodontinae comprise a highly diversified group in the Atlantic Forest, with semifossorial, terrestrial, semiaquatic, scansorial, and arboreal forms. In this study, we analyzed morphometric variation in humerus, scapula, ulna, radius, femur, tibia, and pelvis to investigate its possible relationship with the different types of locomotion recorded in the literature. Skeletal characters were measured in 321 specimens belonging to 29 species and 19 genera either restricted to or recorded in this ecoregion. Multivariate morphometric analyses (principal component and canonical variate analyses) arranged individuals of different genera in groups congruent with the different types of locomotion. This arrangement was more clearly defined when analyses included only forelimb measurements, indicating that most of the variation in appendicular traits associated with the different locomotor modes occurs in the forelimb skeleton. Semifossorial forms exhibited the most distinct appendicular morphology, as well as the greatest frequency of endemism among analyzed species. These results suggest that this mode of locomotion led to greater differentiation in semifossorial Atlantic forest sigmodontines than in terrestrial and arboreal forms, which were found to have more subtle differentiation and fewer endemics. Scansorial species could not be set apart from terrestrial ones in terms of appendicular morphology, suggesting that these two modes of locomotion are the most similar and generalized for the group, as they occur in most lineages in the subfamily. The results of this study corroborate previous observations on the relevance of appendicular characters in the differentiation of species and genera in the subfamily Sigmodontinae. J. Morphol. 2013. © 2013 Wiley Periodicals, Inc.
Reliability and validity of a MR‐based volumetric analysis of the intrinsic foot muscles
Authors: Cheuy Victor A. , Commean Paul K. , Hastings Mary K. , Mueller Michael J.
Published: March 2013

Purpose

To describe a semi‐automated program that will segment subcutaneous fat, muscle, and adipose tissue in the foot using MR imaging, determine the reliability of the program between and within raters, and determine the validity of the program using MR phantoms.

Materials and Methods

MR images were acquired from 19 subjects with and without diabetes and peripheral neuropathy. Two raters segmented and measured volumes from single MR slices at the forefoot, midfoot, and hindfoot at two different times. Intra‐ and inter‐rater correlation coefficients were determined. Muscle and fat MR phantoms of known volumes were measured by the program.

Results

Most ICC reliability values were over 0.950. Validity estimates comparing MR estimates and known volumes resulted in r2 values above 0.970 for all phantoms. The root mean square error was less than 5% for all phantoms.

Conclusion

Subcutaneous fat, lean muscle, and adipose tissue volumes in the foot can be quantified in a reliable and valid way. This program can be applied in future studies investigating the relationship of these foot structures to functions in important pathologies, including the neuropathic foot or other musculoskeletal problems. J. Magn. Reson. Imaging 2013;38:1083–1093. © 2013 Wiley Periodicals, Inc.
Water–fat MRI for assessing changes in bone marrow composition due to radiation and chemotherapy in gynecologic cancer patients
Authors: Bolan Patrick J. , Arentsen Luke , Sueblinvong Thanasak , Zhang Yan , Moeller Steen , Carter Jori S. , Downs Levi S. , Ghebre Rahel , Yee Douglas , Froelich Jerry , Hui Susanta
Published: March 2013

Purpose

To assess the feasibility of using fat‐fraction imaging for measuring marrow composition changes over large regions in patients undergoing cancer therapy.

Materials and Methods

Thirteen women with gynecologic malignancies who were to receive radiation and/or chemotherapy were recruited for this study. Subjects were imaged on a 3T magnetic resonance (MR) scanner at baseline (after surgery but before radiation or chemotherapy), 6 months, and 12 months after treatment. Water–fat imaging was used to generate high‐resolution, 3D signal fat fraction (sFF) maps extending from mid‐femur to L3. Treatment changes were assessed by measuring marrow sFF in the L4 vertebra, femoral necks, and control tissues.

Results

Pretreatment and 6‐month scans were compared in nine women. sFF increased significantly in both the L4 vertebral marrow (P = 0.04) and the femoral necks (P = 0.03), while no significant change was observed in control regions. Qualitatively, chemotherapy changes were more uniform in space, whereas the radiation‐induced changes were largest in marrow regions inside and close to the target radiation field.

Conclusion

Water–fat MRI is sensitive to changes in red/yellow marrow composition, and can be used for quantitative and qualitative assessment of treatment‐induced marrow damage. J. Magn. Reson. Imaging 2013;38:1578–1584. © 2013 Wiley Periodicals, Inc.
Anticholinergic agents result in weaker and shorter suppression of uterine contractility compared with intestinal motion: time course observation with cine MRI
Authors: Daido Sayaka , Nakai Asako , Kido Aki , Okada Tomohisa , Kamae Toshikazu , Fujimoto Koji , Ito Isao , Togashi Kaori
Published: March 2013

Purpose

To evaluate the time course effects of anticholinergic agents on uterine contractility and intestinal motion with cine magnetic resonance imaging (MRI).

Materials and Methods

Using a 1.5 T MRI scanner, 60 T2‐weighted half‐Fourier rapid acquisitions with relaxation enhancement images of the uterus were serially acquired over 3 minutes in 25 healthy women in the periovulatory phase, at four instances, prior to and 2–5, 5–8, and 10–13 minutes after intravenous injection of 20 mg of hyoscine butylbromide. Uterine peristalsis frequency (waves / 3 min) and degrees of endometrial transformation, subendometrial conduction, outer myometrial conduction, sporadic myometrial contraction, and intestinal movement were independently evaluated by three readers.

Results

Uterine peristalsis frequency of 6.14 ± 2.34 decreased the most at 2–5 minutes (P < 0.001) by 1.41 (95% confidential interval [CI] = 0.59–2.22), or 23.0% ([6.14–4.73]/6.14) and remained reduced at 5–8 minutes (P = 0.013) by 0.97 (95% CI = 0.15–1.78), or 15.8% ([6.14–5.17]/6.14) after injection. The degree of intestinal movement was 3.32 ± 0.54 and was prominently reduced at every phase (P < 0.001 for all) and maximally decreased to 0.67 ± 0.65 at 5–8 min. It increased to 1.36 ± 0.72 at 10–13 minutes compared with the degrees of motion at 2–5 minutes (P = 0.04) and 5–8 minutes (P = 0.004).

Conclusion

Suppression of uterine peristalsis was weaker and shorter compared with the stronger and longer suppression of intestinal movement by the intravenous administration of anticholinergic agents. J. Magn. Reson. Imaging 2013;38:1196–1202. © 2013 Wiley Periodicals, Inc.
Tumor‐positive resection margins reflect an aggressive tumor biology in pancreatic cancer
Authors: Kimbrough Charles W. , St. Hill Charles R. , Martin Robert C.G. , McMasters Kelly M. , Scoggins Charles R.
Published: March 2013

Background

Resection margin status has been shown to impact outcomes for pancreatic adenocarcinoma (PAC), yet it remains unknown whether margin status is a reflection of tumor biology or surgical technique.

Methods

Two hundred eighty‐three consecutive patients with pancreatic adenocarcinoma were identified in a prospectively maintained database. Only patients with R0 (n = 207) or R1 (n = 76) tumors were included. Each operative surgeon's first 50 cases were excluded to control for technical inexperience. Univariable and multivariable analyses of clinicopathologic and intra‐operative factors were performed.

Results

The median follow‐up for the cohort was 30.3 months with a median overall survival (OS) of 19.0 months. The R1 group had a higher rate of lymph node ratio >0.2 (41% vs. 25%; P = 0.013), and more microvascular invasion (64% vs. 44%; P = 0.007). R0 resections had both improved overall survival (22.7 months vs. 15.0 months, P = 0.004) and disease free survival (13.5 months vs. 10.7 months, P = 0.026). Factors independently associated with overall survival were microvascular invasion (HR 2.26; P = 0.001), pre‐existing pulmonary disease (HR 2.18, P = 0.043), and cardiac disease (HR 1.78, P = 0.033).

Conclusion

Factors associated with an R1 resection reflect a biologically more aggressive tumor, with a higher likelihood of microvascular invasion and increased positive lymph node ratio. J. Surg. Oncol. 2013;107:602–607. © 2013 Wiley Periodicals, Inc.
Environmental Controls on Fallow Carbon Dioxide Flux in a Single‐Crop Rice Paddy, Japan
Authors: Ono K. , Mano M. , Han G. H. , Nagai H. , Yamada T. , Kobayashi Y. , Miyata A. , Inoue Y. , Lal R.
Published: March 2013

Soil organic carbon (SOC) is one of the important measures of soil fertility and sustainability in arable lands. With continuous CO2 flux measurements, this study assessed the SOC decomposition and its environmental controls at both half‐hourly and season‐long scales in a single‐crop rice (Oryza sativa L.) paddy during three fallow periods between 2004 and 2007. Measurements were made on a gray lowland soil sited in eastern Japan using the eddy covariance method. Ecosystem respiration was strongly affected by soil water content measured at 0–0·1 m depth. At 0·5 m3 m− 3 or more of soil water content, the baseline of ecosystem respiration decreased by 50% compared with that at 0·2 m3 m− 3 . The effect was quantified at half‐hourly scale using an empirical multiple regression model, together with the soil surface temperature and the time after residue incorporation. At season‐long scale, net biome production, which is equivalent to the change in the SOC pool during the fallow period, was estimated from the flux and ancillary data at 150 g C m− 2 in 2004–2005, 70 g m− 2 in 2005–2006, and 270 g C m− 2 in 2006–2007. Apparently, as much as 46 to 79% of the soil organic matter incorporated (crop residues, ratoon, and stable manure) was decomposed during the fallow period. Precipitation, or associated soil water content, was important for the carbon balance of the field at season‐long scale because of its large interannual variability and relatively low permeability of the paddy soil. Copyright © 2013 John Wiley & Sons, Ltd.
Material response during nanosecond laser induced breakdown inside of the exit surface of fused silica
Authors: Demos Stavros G. , Negres Raluca A. , Raman Rajesh N. , Rubenchik Alexander M. , Feit Michael D.
Published: March 2013

The material response following nanosecond, UV laser induced breakdown inside of the exit surface of fused silica is investigated using multimodal time resolved microscopy. The study spans up to about 75 ns delay from the onset of material modification during the laser pulse through the observation of material ejection. A number of distinct processes were identified, including: a) the onset of optical absorption in the material arising from the buildup of an electronic excitation, b) the expansion of the hot modified region (plasma) along the surface and inside the bulk, c) the formation of radial and circumferential cracks, d) the swelling of the affected region on the surface and, e) the onset of ejection of material clusters at about 30 ns delay and its progression to a well‐defined jet by about 75 ns delay. Limited theoretical modeling is used to aid the interpretation of the data.
A randomized, double‐blind, placebo‐controlled trial of pridopidine in Huntington's disease
Authors:   The Huntington Study Group HART Investigators
Published: March 2013

We examined the effects of 3 dosages of pridopidine, a dopamine‐stabilizing compound, on motor function and other features of Huntington's disease, with additional evaluation of its safety and tolerability. This was a randomized, double‐blind, placebo‐controlled trial in outpatient neurology clinics at 27 sites in the United States and Canada. Two hundred twenty‐seven subjects enrolled from October 24, 2009, to May 10, 2010. The intervention was pridopidine, either 20 (n=56), 45 (n=55), or 90 (n=58) mg daily for 12 weeks or matching placebo (n=58). The primary outcome measure was the change from baseline to week 12 in the Modified Motor Score, a subset of the Unified Huntington's Disease Rating Scale Total Motor Score. Measures of safety and tolerability included adverse events and trial completion on the assigned dosage. After 12 weeks, the treatment effect (relative to placebo, where negative values indicate improvement) of pridopidine 90 mg/day on the Modified Motor Score was −1.2 points (95% confidence interval [CI], −2.5 to 0.1 points; P = .08). The effect on the Total Motor Score was −2.8 points (95% CI, −5.4 to −0.1 points; nominal P = .04). No significant effects were seen in secondary outcome measures with any of the active dosages. Pridopidine was generally well tolerated. Although the primary analysis did not demonstrate a statistically significant treatment effect, the overall results suggest that pridopidine may improve motor function in Huntington's disease. The 90 mg/day dosage appears worthy of further study. Pridopidine was well tolerated. © 2013 International Parkinson and Movement Disorder Society
Lessons for inductive germline determination
Authors: Seervai Riyad N.H. , Wessel Gary M.
Published: March 2013

Formation of the germline in an embryo marks a fresh round of reproductive potential, yet the developmental stage and location within the embryo where the primordial germ cells (PGCs) form differs wildly among species. In most animals, the germline is formed either by an inherited mechanism, in which maternal provisions within the oocyte drive localized germ‐cell fate once acquired in the embryo, or an inductive mechanism that involves signaling between cells that directs germ‐cell fate. The inherited mechanism has been widely studied in model organisms such as Drosophila melanogaster, Caenorhabditis elegans, Xenopus laevis, and Danio rerio. Given the rapid generation time and the effective adaptation for laboratory research of these organisms, it is not coincidental that research on these organisms has led the field in elucidating mechanisms for germline specification. The inductive mechanism, however, is less well understood and is studied primarily in the mouse (Mus musculus). In this review, we compare and contrast these two fundamental mechanisms for germline determination, beginning with the key molecular determinants that play a role in the formation of germ cells across all animal taxa. We next explore the current understanding of the inductive mechanism of germ‐cell determination in mice, and evaluate the hypotheses for selective pressures on these contrasting mechanisms. We then discuss the hypothesis that the transition between these determination mechanisms, which has happened many times in phylogeny, is more of a continuum than a binary change. Finally, we propose an analogy between germline determination and sex determination in vertebrates—two of the milestones of reproduction and development—in which animals use contrasting strategies to activate similar pathways. Mol. Reprod. Dev. 80:590–609, 2013. © 2013 Wiley Periodicals, Inc.
Remote monitoring of videourodynamics using smart phone and free instant messaging software
Authors: Hsieh Po‐Fan , Chang Chao‐Hsiang , Lien Chi‐Shun , Wu Hsi‐Chin , Hsiao Po‐Jen , Chou Eric Chieh‐Lung
Published: March 2013

Aims

To evaluate the feasibility of using smart phones plus free instant messaging software for remote monitoring of videourodynamics.

Methods

From November 2011 to October 2012, 85 females with voiding disorders were enrolled for videourodynamic tests. The patients were assigned to videourodynamics remotely monitored by the attending physician by using iPhone/iPad and Skype (group 1) and videourodynamics with the attending physician present (group 2). The procedural time and videourodynamic qualities, assessed by the frequency of adherence to the modified Sullivan criteria, in each group were recorded and compared.

Results

There were 44 and 41 patients in group 1 and group 2, respectively. The mean procedural time was comparable between group 1 and group 2 (56.3 vs. 54.4 min, P = 0.25). The frequencies of adherence to the modified Sullivan criteria were similar in each group.

Conclusions

The qualities of videourodynamics under the attending physician's remote or direct monitoring were both appropriate. Based on the convenience of Internet, the popularity of smart phones and the intention to make the urologists use their time more efficiently, our study provides remote monitoring as an alternative way for performing videourodynamics. Neurourol. Urodynam. 32:1064–1067, 2013. © 2013 Wiley Periodicals, Inc.
An adaptive level set method based on two‐level uniform meshes and its application to dislocation dynamics
Authors: Wang Hanquan , Xiang Yang
Published: March 2013

In this paper, we present an adaptive level set method for motion of high codimensional objects (e.g., curves in three dimensions). This method uses only two (or a few fixed) levels of meshes. A uniform coarse mesh is defined over the whole computational domain. Any coarse mesh cell that contains the moving object is further divided into a uniform fine mesh. The coarse‐to‐fine ratios in the mesh refinement can be adjusted to achieve optimal efficiency. Refinement and coarsening (removing the fine mesh within a coarse grid cell) are performed dynamically during the evolution. In this adaptive method, the computation is localized mostly near the moving objects; thus, the computational cost is significantly reduced compared with the uniform mesh over the whole domain with the same resolution. In this method, the level set equations can be solved on these uniform meshes of different levels directly using standard high‐order numerical methods. This method is examined by numerical examples of moving curves and applications to dislocation dynamics simulations. This two‐level adaptive method also provides a basis for using locally varying time stepping to further reduce the computational cost. Copyright © 2013 John Wiley & Sons, Ltd.
A four‐node corotational quadrilateral elastoplastic shell element using vectorial rotational variables
Authors: Li Z.X. , Zhuo X. , Vu‐Quoc L. , Izzuddin B.A. , Wei H.Y.
Published: March 2013

A four‐node corotational quadrilateral elastoplastic shell element is presented. The local coordinate system of the element is defined by the two bisectors of the diagonal vectors generated from the four corner nodes and their cross product. This local coordinate system rotates rigidly with the element but does not deform with the element. As a result, the element rigid‐body rotations are excluded in calculating the local nodal variables from the global nodal variables. The two smallest components of each nodal orientation vector are defined as rotational variables, leading to the desired additive property for all nodal variables in a nonlinear incremental solution procedure. Different from other existing corotational finite‐element formulations, the resulting element tangent stiffness matrix is symmetric owing to the commutativity of the local nodal variables in calculating the second derivative of strains with respect to these variables. For elastoplastic analyses, the Maxwell–Huber–Hencky–von Mises yield criterion is employed, together with the backward‐Euler return‐mapping method, for the evaluation of the elastoplastic stress state; the consistent tangent modulus matrix is derived. To eliminate locking problems, we use the assumed strain method. Several elastic patch tests and elastoplastic plate/shell problems undergoing large deformation are solved to demonstrate the computational efficiency and accuracy of the proposed formulation. Copyright © 2013 John Wiley & Sons, Ltd.