bluuebunny/crossref_metadata_2025 huggingface dataset:
An improved approach for remotely sensing water stress impacts on forest C uptake
Authors: Sims Daniel A. , Brzostek Edward R. , Rahman Abdullah F. , Dragoni Danilo , Phillips Richard P.
Published: January 2014

Given that forests represent the primary terrestrial sink for atmospheric CO2, projections of future carbon (C) storage hinge on forest responses to climate variation. Models of gross primary production (GPP) responses to water stress are commonly based on remotely sensed changes in canopy ‘greenness’ (e.g., normalized difference vegetation index; NDVI). However, many forests have low spectral sensitivity to water stress (SSWS) – defined here as drought‐induced decline in GPP without a change in greenness. Current satellite‐derived estimates of GPP use a vapor pressure deficit (VPD) scalar to account for the low SWSS of forests, but fail to capture their responses to water stress. Our objectives were to characterize differences in SSWS among forested and nonforested ecosystems, and to develop an improved framework for predicting the impacts of water stress on GPP in forests with low SSWS. First, we paired two independent drought indices with NDVI data for the conterminous US from 2000 to 2011, and examined the relationship between water stress and NDVI. We found that forests had lower SSWS than nonforests regardless of drought index or duration. We then compared satellite‐derived estimates of GPP with eddy‐covariance observations of GPP in two deciduous broadleaf forests with low SSWS: the Missouri Ozark (MO) and Morgan Monroe State Forest (MMSF) AmeriFlux sites. Model estimates of GPP that used VPD scalars were poorly correlated with observations of GPP at MO (r2 = 0.09) and MMSF (r2 = 0.38). When we included the NDVI responses to water stress of adjacent ecosystems with high SSWS into a model based solely on temperature and greenness, we substantially improved predictions of GPP at MO (r2 = 0.83) and for a severe drought year at the MMSF (r2 = 0.82). Collectively, our results suggest that large‐scale estimates of GPP that capture variation in SSWS among ecosystems could improve predictions of C uptake by forests under drought.
Local and systemic tissue response submitted to injection of 2 and 30% polymethylmethacrylate in rats′ tongue
Authors: Vargas Karlon F. , Borghetti Ruchielli L. , Moure Sabrina P. , Cherubini Karen , de Figueiredo Maria Antonia Z.
Published: January 2014

Introduction

Adverse effects on the oral mucosa after the use of dermal fillers have been reported due to their increased use for facial aesthetics.

Objective

This study aimed to evaluate, clinically and histologically, the local and systemic effects of two concentrations of polymethylmethacrylate (PMMA) dermal filler in rats.

Material and methods

Fifty‐four female rats were allocated into three treatment groups (2% PMMA, 30% PMMA and 0.9% NaCl), according to the substance injected in the tongue, and three experimental periods: 7, 60 and 90 days. The rats were clinically evaluated and then euthanised, and their tongue and right kidney removed. The histological sections were stained with haematoxylin/eosin and picrosirius.

Results

Clinically, significant differences were found between test groups as to the occurrence of nodules (Kruskal–Wallis; p < 0.001). Histologically, there was greater inflammatory response in the PMMA compared with control (Kruskal–Wallis; p < 0.001). 30% PMMA had greater collagen formation (anova mixed models; p < 0.01). No migration of the material towards kidney was found.

Conclusion

Polymethylmethacrylate induced intense reaction in the initial period of observation (7 days), followed by gradual decrease during the study, favouring the presence of fibroplasia adjacent to the material.
Parkinson Activity Scale: Cross‐cultural adaptation and reliability of the Brazilian version
Authors: Santos Mariana P , Ovando Angélica C , Silva Bruna A , Fontana Samanta RCB , do Espírito Santo Caroline C , Ilha Jocemar , Swarowsky Alessandra
Published: January 2014

Aim

Following the substantial growth of the elderly population in Brazil, there has been an increase in cases of Parkinson's disease (PD), which raises the need for reliable and culturally adapted scales specific to the disease. The Parkinson Activity Scale (PAS) was developed in order to assess the activity level of people with PD through tasks related to mobility. The aims of the present study were to translate the cross‐cultural adaptation of the PAS into Brazillian Portuguese and analyze its reliability during the “on” phase of PD.

Methods

A total of 25 patients with PD participated in the study. The intrarater reliability was evaluated using a test–retest design with a 1‐week interval.

Results

The interrater reliability was tested twice on the same day by two different raters. The intraclass correlation coefficient (ICC), and the Bland and Altman plots were calculated to examine the test–retest and interrater reliabilities for total score of the PAS, whereas the weighted Kappa (Wk) was used to assess interrater agreement. The interrater ICC was 0.89 and Wk was 0.65 for the total score. For intrarater reliability, the total score ICC was 0.88.

Conclusions

The present study suggests that the Brazilian version of the PAS is a reliable instrument for the assessment of mobility in elderly patients with PD. Geriatr Gerontol Int 2015; 15: 89–95.
Landslide prediction from machine learning
Authors: Korup Oliver , Stolle Amelie
Published: January 2014

Predicting where and when landslides are likely to occur in a specific region of interest remains a key challenge in natural hazards research and mitigation. While the basic mechanics of slope‐failure initiation and runout can be cast into physical and numerical models, a scarcity of sufficiently detailed and real‐time measurements of soil, rock‐mass and groundwater conditions prohibits accurate landslide forecasting. Researchers are therefore increasingly exploring multivariate data analysis techniques from the fields of data mining or machine learning in order to approximate future occurrences of landslides from past distribution patterns. This work has elucidated patterns of spatial susceptibility, but temporal forecasts have remained largely empirical. Most machine learning techniques achieve overall success rates of 75–95 percent. Whilst this may seem very promising, issues remain with data input quality, potential overfitting and commensurate inadequate choice of prediction models, inadvertent inclusion of redundant or noise variables, and technical limits to predicting only certain types and sizes of landslides. Simpler models provide only slightly inferior predictions to more complex models, and should guide the way for a more widespread application of data mining in regional landslide prediction. This approach should especially be communicated to planners and decision makers. Future research may want to develop: (1) further best‐practice guidelines for model selection; (2) predictions of occurrence and runout of large slope failures at the regional scale; and (3) temporal forecasts of landslides.
Coping in adult patients with severe haemophilia
Authors: Binnema M. , Schrijvers L. H. , Bos R. , Schuurmans M. J. , Fischer K.
Published: January 2014

An adequate use of coping strategies could help patients to deal with disease‐related stress. The study aim was to explore coping behaviour in adult patients with severe haemophilia and its possible determinants. Coping was assessed through three basic dimensions (task‐oriented, emotion‐oriented and avoidance coping), using the short version of the Coping Inventory for Stressful Situations (CISS‐21). Patients' scores were compared with Dutch working men (N = 374), according to three categories: low use (P75). Determinants were measured using questionnaires on activities (Haemophilia Activities List), participation (Impact on Participation and Autonomy Questionnaire), physical functioning [physical component of the Dutch Arthritis Impact Measurement Scales‐2 (D‐AIMS2)] and socio‐psychological health (psychological component of the D‐AIMS2). In total, 86 adults with severe haemophilia (FVIII/IX<1%) were included. The median age was 38 years (range: 18–68) with 85% affected with haemophilia A and 75% using prophylaxis. Patients with haemophilia used task‐oriented coping as frequently as the control group (P = 0.13); but used significantly less emotion‐oriented coping (57% vs. 25%, P < 0.05) and avoidance coping (P < 0.05). Emotion‐oriented coping showed a strong correlation with socio‐psychological health (r = 0.67) and weak correlations with participation (r = 0.32) and social interaction (r = 0.29). Other associations of coping strategies with patient characteristics of health status could not be demonstrated. Overall, patients predominantly used the task‐oriented approach to deal with their disease; the use of this strategy was comparable to the control group. Having a poor psychological health, less social interaction and/or less participation in daily life was associated with an increased use of emotion‐oriented coping.
Islets of Langerhans from prohormone convertase‐2 knockout mice show α‐cell hyperplasia and tumorigenesis with elevated α‐cell neogenesis
Authors: Jones Huw B. , Reens Jaimini , Brocklehurst Simon R. , Betts Catherine J. , Bickerton Sue , Bigley Alison L. , Jenkins Richard P. , Whalley Nicky M. , Morgan Derrick , Smith David M.
Published: January 2014

Antagonism of the effects of glucagon as an adjunct therapy with other glucose‐lowering drugs in the chronic treatment of diabetes has been suggested to aggressively control blood glucose levels. Antagonism of glucagon effects, by targeting glucagon secretion or disabling the glucagon receptor, is associated with α‐cell hyperplasia. We evaluated the influence of total glucagon withdrawal on islets of Langerhans using prohormone convertase‐2 knockout mice (PC2‐ko), in which α‐cell hyperplasia is present from a young age and persists throughout life, in order to understand whether or not sustained glucagon deficit would lead to islet tumorigenesis. PC2‐ko and wild‐type (WT) mice were maintained drug‐free, and cohorts of these groups sampled at 3, 12 and 18 months for plasma biochemical and morphological (histological, immunohistochemical, electron microscopical and image analytical) assessments. WT mice showed no islet tumours up to termination of the study, but PC2‐ko animals displayed marked changes in islet morphology from α‐cell hypertrophy/hyperplasia/atypical hyperplasia, to adenomas and carcinomas, these latter being first encountered at 6–8 months. Islet hyperplasias and tumours primarily consisted of α‐cells associated to varying degrees with other islet endocrine cell types. In addition to substantial increases in islet neoplasia, increased α‐cell neogenesis associated primarily with pancreatic duct(ule)s was present. We conclude that absolute blockade of the glucagon signal results in tumorigenesis and that the PC2‐ko mouse represents a valuable model for investigation of islet tumours and pancreatic ductal neogenesis.
Effects of pepsin hydrolysis on the soy β‐conglycinin aggregates formed by heat treatment at different pH
Authors: He Xiu‐Ting , Yang Xiao‐Quan , Zhang Jin‐Bo
Published: January 2014

The effects of pepsin hydrolysis on the β‐conglycinin aggregates formed by heat treatment at different pH were investigated. Results showed that fibrils were still observed, whereas the random aggregates were easily to be digested in the simulated gastric fluid. Electrophoresis and molecular weight analysis indicated that large aggregates still existed after pepsin treatment for fibrils. Hydrolysis resulted in changes in the apparent viscosity (ηapp) of 6% fibril solutions. The ηapp at the shear rate range (0–30 s−1) increased in the order of fibrils < fibrils with pepsin for 60 min < fibrils with pepsin for 30 min. Smaller peptide/fibril fragments were generated, and additional aggregates were reformed during the hydrolysis process, as evidenced by thioflavin T and atomic force microscopy images. The native β‐conglycinin hydrolysates comprised a mixture of polypeptides enriched in about 47 kDa. These findings would provide valuable information about effects of enzymatic hydrolysis on plant oligometric globulin aggregates.
Exploring factors that contribute to dose administration aid incidents and identifying quality improvement strategies: the views of pharmacy and nursing staff
Authors: Gilmartin Julia F-M , Marriott Jennifer L , Hussainy Safeera Y
Published: January 2014

Background

Dose administration aids (DAAs) organise medicines that have been repacked according to the day of the week and time of the day in which they must be taken. In Australia, DAAs are commonly prepared by pharmacy staff for residential aged care facility (RACF) medicine administration. Although the limited available literature indicates that DAA incidents of inaccurate or unsuitable medicine repacking do occur, there is a paucity of qualitative research identifying quality improvement strategies for this service.

Objectives

This study aims to investigate the perceived contributing factors to DAA incidents and strategies for quality improvement in RACFs and pharmacies.

Methods

Health professional perceptions were drawn from three structured focus groups, including six pharmacists, five nurses, a pharmacy technician and a personal care worker. Participants were involved in the preparation, supply or use of DAAs at pharmacies or RACFs that were involved in a previous DAA audit. Transcripts were analysed using thematic analysis.

Key findings

Four major themes were identified as contributing to DAA incidents, with quality improvement strategies aligned to those same four themes: communication, knowledge and awareness, medicine handling and attitude. Strategies included improving interprofessional communication and addressing the limitations associated with RACF medicine records; targeting medicine knowledge gaps and increasing awareness of DAA incidents; encouraging greater care when preparing and checking DAAs; and fostering a team mentality among members of the aged care team.

Conclusions

Recommendations include using current findings to develop multidisciplinary quality improvement initiatives to prevent DAA incidents and to improve the quality of this pharmacy medicine supply service.
Sterols and steroids in a freshwater crustacean (Proasellus meridianus): hormonal response to nutritional input
Authors: Mondy Nathalie , Grossi Vincent , Cathalan Eva , Delbecque Jean‐Paul , Mermillod‐Blondin Florian , Douady Christophe J.
Published: January 2014

For crustaceans that eat shredded plant material in freshwater habitats, the amount and the composition of food greatly vary over time because of the seasonal succession of plant fragments and algal biomass. The acquisition of elements necessary for growth, immune defense, and reproduction depends largely on this variation in food type and availability. In particular, sterols that are required as cellular membrane components and as precursors of ecdysteroids (molting hormones) must be acquired through food because crustaceans do not synthesize the steroid nucleus de novo. The present study examined the possible link between nutrition, sterols, and ecdysteroids in an isopod, Proasellus meridianus. In a first step, quantitative and qualitative analyses of sterols of P. meridianus were performed by gas‐chromatography/mass spectrometry. The results suggested that members of P. meridianus are able to convert dietary plant sterols into cholesterol required for growth and reproduction. In a second step, by manipulating food availability and using an enzyme immuno‐assay, we showed that ecdysteroid content in males and females (ovigerous or not) of P. meridianus decreased significantly after a starvation period. A nutritional input following this starvation period triggered an increase in the ecdysteroid contents of these animals. The comparable ecdysteroid responses to food pulses in males and females suggested that a nutritional control on steroid hormones regulated growth or gametogenesis rather than egg maturation. Thus, it appears that P. meridianus possesses an efficient stop‐and‐go endocrine system that may have been selectively favored in response to seasonal pulses of food.
Trichostatin A, a histone deacetylase inhibitor, suppresses proliferation and epithelial–mesenchymal transition in retinal pigment epithelium cells
Authors: Xiao Wei , Chen Xiaoyun , Liu Xialin , Luo Lixia , Ye Shaobi , Liu Yizhi
Published: January 2014

The proliferation and epithelial–mesenchymal transition (EMT) of retinal pigment epithelium (RPE) cells are the major pathological changes in development of proliferative vitreoretinopathy (PVR), which leads to severe visual impairment. Histone deacetylases (HDACs)‐mediated epigenetic mechanisms play important roles in controlling various physiological and pathological events. However, whether HDACs are involved in the regulation of proliferation and EMT in PRE cells remains unidentified. In this study, we evaluated the expression profile of HDAC family (18 genes) and found that some of class I and class II HDACs were up‐regulated in transforming growth factor‐β2 (TGF‐β2)/TGF‐β1‐stimulated RPE cells. Tricostatin A (TSA), a class I and II HDAC inhibitor, suppressed the proliferation of RPE cells by G1 phase cell cycle arrest through inhibition of cyclin/CDK/p‐Rb and induction of p21 and p27. In the meantime, TSA strongly prevented TGF‐β2–induced morphological changes and the up‐regulation of α‐SMA, collagen type I, collagen type IV, fibronectin, Snail and Slug. We also demonstrated that TSA affected not only the canonical Smad signalling pathway but also the non‐canonical TGF‐β/Akt, MAPK and ERK1/2 pathways. Finally, we found that the underlying mechanism of TSA affects EMT in RPE cells also through down‐regulating the Jagged/Notch signalling pathway. Therefore, this study may provide a new insight into the pathogenesis of PVR, and suggests that epigenetic treatment with HDAC inhibitors may have therapeutic value in the prevention and treatment of PVR.
Nanofiber‐expanded human umbilical cord blood–derived CD34+ cell therapy accelerates cutaneous wound closure in NOD/SCID mice
Authors: Kanji Suman , Das Manjusri , Aggarwal Reeva , Lu Jingwei , Joseph Matthew , Pompili Vincent J. , Das Hiranmoy
Published: January 2014

Nanofiber‐expanded human umbilical cord blood–derived CD34+ cell therapy has been shown to have potential applications for peripheral and myocardial ischaemic diseases. However, the efficacies of expanded CD34+ cell therapy for treating cutaneous wounds and its mechanisms of action have yet to be established. Using an excisional wound model in non‐obese diabetic/severe combined immune deficient mice, we show herein that CD34+ cells accelerate the wound‐healing process by enhancing collagen synthesis, and increasing fibroblast cell migration within the wound bed. Concomitantly, reduced levels of matrix metalloproteinase (MMPs) such as MMP1, MMP3, MMP9 and MMP13 were detected in the wound beds of animals treated with CD34+ cells compared with vehicle‐treated controls. CD34+ cells were found to mediate enhanced migration and proliferation of dermal fibroblast cells in vitro. Moreover, CD34+ cells secrete collagen in a serum‐deprived environment. In mechanistic studies, co‐culture of CD34+ cells with primary skin fibroblasts increased the expression of collagen1A1, a component of type 1 collagen, and decreased the expression of MMP1 in fibroblast cells in the presence of a proteasome inhibitor. Finally, CD34+ cell–mediated functions were transcriptionally regulated by the c‐Jun N‐terminal kinases pathway. Collectively, these data provide evidence of therapeutic efficacy and a novel mechanism of nanofiber‐expanded CD34+ cell–mediated accelerated wound healing.
Serum miR‐206 and other muscle‐specific microRNAs as non‐invasive biomarkers for Duchenne muscular dystrophy
Authors: Hu Jun , Kong Min , Ye Yuanzhen , Hong Siqi , Cheng Li , Jiang Li
Published: January 2014

Creatine kinase has been utilized as a diagnostic marker for Duchenne muscular dystrophy (DMD), but it correlates less well with the DMD pathological progression. In this study, we hypothesized that muscle‐specific microRNAs (miR‐1, ‐133, and ‐206) in serum may be useful for monitoring the DMD pathological progression, and explored the possibility of these miRNAs as potential non‐invasive biomarkers for the disease. By using real‐time quantitative reverse transcription–polymerase chain reaction in a randomized and controlled trial, we detected that miR‐1, ‐133, and ‐206 were significantly over‐expressed in the serum of 39 children with DMD (up to 3.20 ± 1.20, 2−ΔΔCt): almost 2‐ to 4‐fold enriched in comparison to samples from the healthy controls (less than 1.15 ± 0.34, 2−ΔΔCt). To determine whether these miRNAs were related to the clinical features of children with DMD, we analyzed the associations compared to creatine kinase. There were very good inverse correlations between the levels of these miRNAs, especially miR‐206, and functional performances: high levels corresponded to low muscle strength, muscle function, and quality of life. Moreover, by receiver operating characteristic curves analyses, we revealed that these miRNAs, especially miR‐206, were able to discriminate DMD from controls. Thus, miR‐206 and other muscle‐specific miRNAs in serum are useful for monitoring the DMD pathological progression, and hence as potential non‐invasive biomarkers for the disease.

image

There has been a long‐standing need for reliable, non‐invasive biomarkers for Duchenne muscular dystrophy (DMD). We found that the levels of muscle‐specific microRNAs, especially miR‐206, in the serum of DMD were 2‐ to 4‐fold higher than in the controls. High levels corresponded to low muscle strength, muscle function, and quality of life (QoL). These miRNAs were able to discriminate DMD from controls by receiver operating characteristic (ROC) curves analyses. Thus, miR‐206 and other muscle‐specific miRNAs are useful as non‐invasive biomarkers for DMD.
Attitudinal Factors Protective Against Youth Smoking: An Integrative Review
Authors: Arens Carissa Renée , White Tiffany Lynn , Massengill Nichole
Published: January 2014

Purpose

This review examines recent literature with the purpose of uncovering associations between attitudinal factors and smoking among youth populations.

Organizing Construct and Methods

Researchers conducted an integrative review of the literature in late 2012 and early 2013. As inclusion criteria, potential articles were measured against the following statement: “There is valid evidence of (an) attitudinal factor(s) potentially associated with smoking among youth.”

Findings

Researchers employed the salutogenic model as a theoretical framework to analyze search results. The narrative synthesis indicates that primary attitudinal factors protective against smoking among youth include the following: (a) a perception that there is little benefit to smoking, (b) a belief that smoking is likely harmful and addictive in the short term, and (c) a denial that smoking provides stress abatement, makes one look cool or more grown‐up, or is common and accepted. Moreover, research signals that youth who smoke often demonstrate essentially the opposite beliefs and attitudes.

Conclusions

Findings suggest attitudinal factors play a role in protection against youth smoking. Those youth who assign realistic values to smoking risks and benefits are more equipped to engage in the health‐protective behavior of not smoking. Youth, adolescents, and young adults appear vulnerable to inappropriate designation of risk and benefit values of smoking. Theoretical interpretation suggests that bolstering attitudinal factors during youth might counteract immature risk assessment. These findings justify further research related to protective mechanisms against youth smoking and youth‐based smoking prevention interventions.

Clinical Relevance

The establishment of associations between attitudinal factors and protection against smoking can help determine interventions effective in reducing smoking among youth.
Safewards: the empirical basis of the model and a critical appraisal
Authors: Bowers L. , Alexander J. , Bilgin H. , Botha M. , Dack C. , James K. , Jarrett M. , Jeffery D. , Nijman H. , Owiti J. A. , Papadopoulos C. , Ross J. , Wright S. , Stewart D.
Published: January 2014

Accessible summary

In the previous paper we described a model explaining differences in rates of conflict and containment between wards, grouping causal factors into six domains: the staff team, the physical environment, outside hospital, the patient community, patient characteristics and the regulatory framework.

This paper reviews and evaluates the evidence for the model from previously published research.

The model is supported, but the evidence is not very strong. More research using more rigorous methods is required in order to confirm or improve this model.

In a previous paper, we described a proposed model explaining differences in rates of conflict (aggression, absconding, self‐harm, etc.) and containment (seclusion, special observation, manual restraint, etc.). The Safewards Model identified six originating domains as sources of conflict and containment: the patient community, patient characteristics, the regulatory framework, the staff team, the physical environment, and outside hospital. In this paper, we assemble the evidence underpinning the inclusion of these six domains, drawing upon a wide ranging review of the literature across all conflict and containment items; our own programme of research; and reasoned thinking. There is good evidence that the six domains are important in conflict and containment generation. Specific claims about single items within those domains are more difficult to support with convincing evidence, although the weight of evidence does vary between items and between different types of conflict behaviour or containment method. The Safewards Model is supported by the evidence, but that evidence is not particularly strong. There is a dearth of rigorous outcome studies and trials in this area, and an excess of descriptive studies. The model allows the generation of a number of different interventions in order to reduce rates of conflict and containment, and properly conducted trials are now needed to test its validity.
A Cognitive View of Reading Comprehension: Implications for Reading Difficulties
Authors: Kendeou Panayiota , van den Broek Paul , Helder Anne , Karlsson Josefine
Published: January 2014

Our aim in the present paper is to discuss a “cognitive view” of reading comprehension, with particular attention to research findings that have the potential to improve our understanding of difficulties in reading comprehension. We provide an overview of how specific sources of difficulties in inference making, executive functions, and attention allocation influence reading comprehension processes and outcomes and may lead to reading comprehension problems. Finally, we discuss how the consideration of these potential sources of difficulty have practical implications for the design and selection of instructional materials.
Functional and phylogenetic diversity of woody plants drive herbivory in a highly diverse forest
Authors: Schuldt Andreas , Assmann Thorsten , Bruelheide Helge , Durka Walter , Eichenberg David , Härdtle Werner , Kröber Wenzel , Michalski Stefan G. , Purschke Oliver
Published: January 2014

Biodiversity loss may alter ecosystem processes, such as herbivory, a key driver of ecological functions in species‐rich (sub)tropical forests. However, the mechanisms underlying such biodiversity effects remain poorly explored, as mostly effects of species richness – a very basic biodiversity measure – have been studied. Here, we analyze to what extent the functional and phylogenetic diversity of woody plant communities affect herbivory along a diversity gradient in a subtropical forest.

We assessed the relative effects of morphological and chemical leaf traits and of plant phylogenetic diversity on individual‐level variation in herbivory of dominant woody plant species across 27 forest stands in south‐east China.

Individual‐level variation in herbivory was best explained by multivariate, community‐level diversity of leaf chemical traits, in combination with community‐weighted means of single traits and species‐specific phylodiversity measures. These findings deviate from those based solely on trait variation within individual species.

Our results indicate a strong impact of generalist herbivores and highlight the need to assess food‐web specialization to determine the direction of biodiversity effects. With increasing plant species loss, but particularly with the concomitant loss of functional and phylogenetic diversity in these forests, the impact of herbivores will probably decrease – with consequences for the herbivore‐mediated regulation of ecosystem functions.
Almost‐Ontology: Why Epistemicism Cannot Help Us Avoid Unrestricted Composition or Diachronic Plenitude
Authors: Steen İrem Kurtsal
Published: January 2014

That any filled location of spacetime contains a persisting thing has been defended based on the ‘argument from vagueness.’ It is often assumed that since the epistemicist account of vagueness blocks the argument from vagueness it facilitates a conservative ontology without gerrymandered objects. It doesn't. The epistemic vagueness of ordinary object predicates such as ‘bicycle’ requires that objects that can be described asalmost‐but‐not‐quite‐bicycleexist even though they fall outside the predicate's sharp extension. Since the predicates that begin with ‘almost’ are vague as well, epistemicism's ontological backdrop is far from the conservative picture it is thought to enable.
Streptococcus pyogenes Cervical Intertrigo with Secondary Bacteremia
Authors: López‐Corominas Victoria , Yagüe Francisca , Knöpfel Nicole , Dueñas Joaquín , Gil José , Martín‐Santiago Ana , Hervás Juan A.
Published: January 2014

We report a 12‐month‐old infant girl with cervical intertrigo caused by Streptococcus pyogenes. This form of intertrigo has been reported in only five children, but it is clearly underestimated. It should be suspected for well‐demarcated beefy‐red lesions of the neck not responding to antifungal therapy. A rapid streptococcal antigen test of a lesion specimen is a useful diagnostic tool. Our patient was notable for the development of S. pyogenes bacteremia, a complication that has not been previously associated with this condition.
Two Cases of Lichen Striatus with Prolonged Active Phase
Authors: Feely Meghan A. , Silverberg Nanette B.
Published: January 2014

Lichen striatus is a localized, eczematous disorder distributed along the lines of Blaschko, primarily affecting children. In the literature, lesions have been described as having an active phase of inflamed lesions for 6 to 12 months followed by flattening and persistent pigmentary alteration. We describe two girls who had prolonged active‐phase lesions for 2.5 and 3.5 years, respectively. Practitioners should be aware that lesions of lichen striatus may have a prolonged active phase.
The novel alleles HLA‐B*44:101 and HLA‐B*57:48 of Caucasian origin are characterized by amino acid substitutions in the alpha 2 domain
Authors: Becker P. S. A. , Seifried E. , Seidl C.
Published: January 2014

HLA‐B*44:101 and HLA‐B*57:48 are characterized by amino acid substitutions in the alpha 2 domain.
Late‐onset Pneumocystis jirovecii pneumonia in solid organ transplant recipients
Authors: Perez‐Ordoño L. , Hoyo I. , Sanclemente G. , Ricart M.J. , Cofan F. , Perez‐Villa F. , de la Bellacasa J. Puig , Moreno A. , Cervera C.
Published: January 2014

Anti‐Pneumocystis prophylaxis is recommended for at least 6–12 months after solid organ transplantation, as most cases of Pneumocystis jirovecii pneumonia (PCP) occur during the first year post transplantation. Herein, we report 4 cases of late‐onset PCP (>1 year post transplant). PCP appeared in a range of 50–68 months post transplant. Two cases had history of humoral rejection episodes treated with rituximab, and the other 2 had low CD4+ T‐cell count (<200 cells/mm3) at the time of diagnosis. All 4 patients survived. In conclusion, although the number of cases is low, we must be aware of the possibility of late‐onset PCP in solid organ transplant patients. The role of previous use of rituximab or persistent CD4+ T‐cell lymphopenia should be addressed in future studies.
Molecular analysis of immunized Jr(a–) or Lan– patients and validation of a high‐throughput genotyping assay to screen blood donors for Jr(a–) and Lan– phenotypes
Authors: Haer‐Wigman Lonneke , Ait Soussan Aïcha , Ligthart Peter , de Haas Masja , van der Schoot C. Ellen
Published: January 2014

Background

Individuals with anti‐Jra or anti‐Lan are ideally transfused with rare Jr(a–) or Lan– red blood cells. We characterized mutations in Dutch Jr(a–) and Lan– individuals and developed a high‐throughput genotyping assay to detect Jr(a–) and Lan– donors.

Study Design and Methods

Six Jr(a–) and seven Lan– persons, who all made anti‐Jra or anti‐Lan, were sequenced for ABCG2 or ABCB6 and the copy number of ABCG2 and ABCB6 was determined. A total of 3366 Caucasian, 621 black, and 333 Chinese donors were screened with a high‐throughput screening assay targeting frequently occurring mutations causing the Jr(a–) or Lan– phenotype.

Results

In the six tested Jr(a–) individuals previously described, c.376C > T, c.706C > T, and c.736C > T nonsense mutations in ABCG2 were detected. In the seven Lan– individuals 12 different mutations, of which 10 underlie the Lan– phenotype, were detected. No copy number variation was detected for ABCG2 and ABCB6. The high‐throughput screening assay detected five Caucasian donors heterozygous for the c.706C > T or 736C > T mutation in ABCG2 and nine Caucasian donors heterozygous for the 574C > T mutation in ABCB6. No black or Chinese donors were found positive for a mutation.

Conclusion

We describe eight new mutations in ABCB6 of which seven, including three missense mutations, underlie the Lan– phenotype and determine that a complete gene deletion of ABCG2 or ABCB6 is not responsible for the Jr(a–) or Lan– phenotype, respectively. The extended heterogeneity of mutations causing the Jr(a–) or Lan– phenotype in most populations makes genetic screening for the Jr(a–) and Lan– phenotype inefficient in those populations.
TOF SIMS analysis and generation of white photoluminescence from strontium silicate codoped with europium and terbium
Authors: Tshabalala Modiehi A. , Swart Hendrik C. , Ntwaeaborwa Odireleng M.
Published: January 2014

White light emitting terbium (Tb3+) and europium (Eu3+) codoped strontium silicate (Sr2SiO4) phosphors were prepared by a solid state reaction process. The structure, particle morphology, chemical composition, ion distribution, photoluminescence (PL), and decay characteristics of the phosphors were analyzed by x-ray diffraction (XRD), scanning electron microscopy (SEM), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and PL spectroscopy, respectively. The XRD data showed that our Sr2SiO4 composed of two phases, namely, β-Sr2SiO4 and α′-Sr2SiO4, and the α′-Sr2SiO4 phase was more prominent than the β-Sr2SiO4 phase. The SEM micrographs showed that the particles were agglomerated together and they did not have definite shapes. All ions (i.e., negative and positive) present in our materials were identified by TOF-SIMS. In addition, the chemical imaging performed with the TOF-SIMS demonstrated how the individual ions including the dopants (Eu3+ and Tb3+) were distributed in the host lattice. White photoluminescence was observed when the Sr2SiO4:Tb3+, Eu3+ phosphor was excited at 239 nm using a monochromatized xenon lamp as the excitation source. The phosphor exhibited fast decay lifetimes implying that it is not a good candidate for long afterglow applications.
Model‐based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom
Authors: Lesperance Marielle , Inglis‐Whalen M. , Thomson R. M.
Published: January 2014

Purpose

: To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with125I, 103Pd, or 131Cs seeds, and to investigate doses to ocular structures.

Methods

: An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user‐code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG‐43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye.

Results

: Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20–30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%–10% and 13%–14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG‐43 simulation by 2%–17% and 29%–34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model simulation by up to 16%. In the full eye model simulations, the average dose to the lens is larger by 7%–9% than the dose to the center of the lens, and the maximum dose to the optic nerve is 17%–22% higher than the dose to the optic disk for all radionuclides. In general, when normalized to the same prescription dose at the tumor apex, doses delivered to all structures of interest in the full eye model are lowest for103Pd and highest for 131Cs, except for the tumor where the average dose is highest for 103Pd and lowest for 131Cs.

Conclusions

: The eye is not radiologically water‐equivalent, as doses from simulations of the plaque in the full eye model differ considerably from doses for the plaque in a water phantom and from simulated TG‐43 calculated doses. This demonstrates the importance of model‐based dose calculations for eye plaque brachytherapy, for which accurate elemental compositions of ocular media are necessary.
A Monte Carlo investigation of low‐Z target image quality generated in a linear accelerator using Varianˈs VirtuaLinaca)
Authors: Parsons David , Robar James L. , Sawkey Daren
Published: January 2014

Purpose:

The focus of this work was the demonstration and validation of VirtuaLinac with clinical photon beams and to investigate the implementation of low‐Z targets in a TrueBeam linear accelerator (Linac) using Monte Carlo modeling.

Methods:

VirtuaLinac, a cloud based web application utilizing Geant4 Monte Carlo code, was used to model the Linac treatment head components. Particles were propagated through the lower portion of the treatment head using BEAMnrc. Dose distributions and spectral distributions were calculated using DOSXYZnrc and BEAMdp, respectively. For validation, 6 MV flattened and flattening filter free (FFF) photon beams were generated and compared to measurement for square fields, 10 and 40 cm wide and at dmax for diagonal profiles. Two low‐Z targets were investigated: a 2.35 MeV carbon target and the proposed 2.50 MeV commercial imaging target for the TrueBeam platform. A 2.35 MeV carbon target was also simulated in a 2100EX Clinac using BEAMnrc. Contrast simulations were made by scoring the dose in the phosphor layer of an IDU20 aSi detector after propagating through a 4 or 20 cm thick phantom composed of water and ICRP bone.

Results:

Measured and modeled depth dose curves for 6 MV flattened and FFF beams agree within 1% for 98.3% of points at depths greater than 0.85 cm. Ninety three percent or greater of points analyzed for the diagonal profiles had a gamma value less than one for the criteria of 1.5 mm and 1.5%. The two low‐Z target photon spectra produced in TrueBeam are harder than that from the carbon target in the Clinac. Percent dose at depth 10 cm is greater by 3.6% and 8.9%; the fraction of photons in the diagnostic energy range (25–150 keV) is lower by 10% and 28%; and contrasts are lower by factors of 1.1 and 1.4 (4 cm thick phantom) and 1.03 and 1.4 (20 cm thick phantom), for the TrueBeam 2.35 MV/carbon and commercial imaging beams, respectively.

Conclusions:

VirtuaLinac is a promising new tool for Monte Carlo modeling of novel target designs. A significant spectral difference is observed between the low‐Z target beam on the Clinac platform and the proposed imaging beam line on TrueBeam, with the former providing greater diagnostic energy content.
Development and evaluation of a prototype tracking system using the treatment couch
Authors: Lang Stephanie , Zeimetz Jörg , Ochsner Gregor , Schmid Daners Marianne , Riesterer Oliver , Klöck Stephan
Published: January 2014

Purpose:

Tumor motion increases safety margins around the clinical target volume and leads to an increased dose to the surrounding healthy tissue. The authors have developed and evaluated a one‐dimensional treatment couch tracking system to counter steer respiratory tumor motion. Three different motion detection sensors with different lag times were evaluated.

Methods:

The couch tracking system consists of a motion detection sensor, which can be the topometrical system Topos (Cyber Technologies, Germany), the respiratory gating system RPM (Varian Medical Systems) or a laser triangulation system (Micro Epsilon), and the Protura treatment couch (Civco Medical Systems). The control of the treatment couch was implemented in the block diagram environment Simulink (MathWorks). To achieve real time performance, the Simulink models were executed on a real time engine, provided by Real‐Time Windows Target (MathWorks). A proportional‐integral control system was implemented. The lag time of the couch tracking system using the three different motion detection sensors was measured. The geometrical accuracy of the system was evaluated by measuring the mean absolute deviation from the reference (static position) during motion tracking. This deviation was compared to the mean absolute deviation without tracking and a reduction factor was defined. A hexapod system was moving according to seven respiration patterns previously acquired with the RPM system as well as according to a sin6 function with two different frequencies (0.33 and 0.17 Hz) and the treatment table compensated the motion.

Results:

A prototype system for treatment couch tracking of respiratory motion was developed. The laser based tracking system with a small lag time of 57 ms reduced the residual motion by a factor of 11.9 ± 5.5 (mean value ± standard deviation). An increase in delay time from 57 to 130 ms (RPM based system) resulted in a reduction by a factor of 4.7 ± 2.6. The Topos based tracking system with the largest lag time of 300 ms achieved a mean reduction by a factor of 3.4 ± 2.3. The increase in the penumbra of a profile (1 × 1 cm2) for a motion of 6 mm was 1.4 mm. With tracking applied there was no increase in the penumbra.

Conclusions:

Couch tracking with the Protura treatment couch is achievable. To reliably track all possible respiration patterns without prediction filters a short lag time below 100 ms is needed. More scientific work is necessary to extend our prototype to tracking of internal motion.
Toward optimal organ at risk sparing in complex volumetric modulated arc therapy: An exponential trade‐off with target volume dose homogeneity
Authors: Tol Jim P. , Dahele Max , Doornaert Patricia , Slotman Ben J. , Verbakel Wilko F. A. R.
Published: January 2014

Purpose:

Conventional radiotherapy typically aims for homogenous dose in the planning target volume (PTV) while sparing organs at risk (OAR). The authors quantified and characterized the trade‐off between PTV dose inhomogeneity (IH) and OAR sparing in complex head and neck volumetric modulated arc therapy plans.

Methods:

Thirteen simultaneous integrated boost plans were created per patient, for ten patients. PTV boost(B)/elective(E) optimization priorities were systematically increased. IHB and IHE, defined as (100% − V95%) + V107%, were evaluated against the average of the mean dose to the combined composite swallowing and combined salivary organs (D‐OARcomp). To investigate the influence of OAR size and position with respect to PTVB/E, OAR dose was evaluated against a modified Euclidean distance (DMB/DME) between OAR and PTV.

Results:

Although the achievable D‐OARcomp for a given level of PTV IH differed between patients, excellent logarithmic fits described the D‐OARcomp/IHB and IHE relationship in all patients (mean R2 of 0.98 and 0.97, respectively). Allowing an increase in average IHB and IHE over a clinically acceptable range, e.g., from 0.4% ± 0.5% to 2.0% ± 2.0% and 6.9% ± 2.8% to 14.8% ± 2.7%, respectively, corresponded to a decrease in average dose to the composite salivary and swallowing structures from 30.3 ± 6.5 to 23.6 ± 4.7 Gy and 32.5 ± 8.3 to 26.8 ± 9.3 Gy. The increase in PTVE IH was mainly accounted for by an increase in V107, by on average 5.9%, rather than a reduction in V95, which was on average only 2%. A linear correlation was found between the OAR dose to composite swallowing structures and contralateral parotid and submandibular gland, with DME (R2 = 0.83, 0.88, 0.95). Only mean ipsilateral parotid dose correlated with DMB (R2 = 0.87).

Conclusions:

OAR sparing is highly dependent on the permitted PTVB/E IH. PTVE IH substantially influences OAR doses. These results are relevant for clinical practice and for future automated treatment‐planning strategies.