bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic of Helicobacter pylori infection
Authors: Mégraud Francis , Floch Pauline , Labenz Joachim , Lehours Philippe
Published: August 2016

There is progress in endoscopy techniques. While it is not yet possible to detect Helicobacter pylori directly in the stomach, it becomes easier to detect the mucosal changes induced by the bacteria. Some small changes can also increase the sensitivity of the invasive tests, for example culture or histology, but the wide use of proton‐pump inhibitors has a negative impact on these tests. Only molecular methods are able to detect a limited load of bacteria, especially by using real‐time PCR but also with new methods, for example dual‐priming oligonucleotide‐based PCR, loop‐medicated isothermal amplification, droplet‐digital PCR or a multiple genetic analysis system. Among the noninvasive tests, urea breath test remains a test of major interest, while there are attempts to develop an ammonia breath test and other nanosensor devices. A new antigen stool test, a chemoluminescence immunoassay using the LIAISON apparatus has also been tested for the first time with success. Despite its limitations, serology remains the most popular test to detect H. pylori antibodies. It also allows pepsinogen dosage which is of interest for detecting atrophy.
Inflammation, immunity, and vaccines for Helicobacter pylori infection
Authors: Velin Dominique , Straubinger Kathrin , Gerhard Markus
Published: August 2016

The tight control of the innate and adaptive immune responses in the stomach mucosa during chronic Helicobacter pylori infection is of prime importance for the bacteria to persist and for the host to prevent inflammation‐driven diseases. This review summarizes recent data on the roles of innate and adaptive immune responses during H. pylori/host interactions. In addition, the latest preclinical developments of H. pylori vaccines are discussed with a special focus on the clinical trial reported by Zeng et al., who provided evidence that oral vaccination significantly reduces the acquisition of natural H. pylori infection in children.
Treatment of Helicobacter pylori infection 2016
Authors: O'Connor Anthony , Fischbach Wolfgang , Gisbert Javier P. , O'Morain Colm
Published: August 2016

Many interesting articles have been published from different parts of the world over the last year assessing various issues around Helicobacter pylori eradication therapy. This article will address the published literature over the last year pertaining to the topic of treatment of H. pylori infection. The main themes that emerge are assessing the efficacy of standard triple therapy, as well as exploring new first‐line treatments, mainly optimized nonbismuth‐containing and bismuth‐containing quadruple therapies with some promising data also emerging on dual therapy. There was also considerable progress in investigating antibiotic resistance rates with much more data emerging from varied parts of the world compared to recent years. Advances in the use of adjunctive therapies, especially probiotic therapies have also been made. Undoubtedly, the eradication of H. pylori remains a worthwhile goal to alleviate the burden of diseases caused by the complications of this infection, including dyspepsia, peptic ulcer disease, and gastric cancer.
Other Helicobacters and gastric microbiota
Authors: De Witte Chloë , Schulz Christian , Smet Annemieke , Malfertheiner Peter , Haesebrouck Freddy
Published: August 2016

This article aimed to review the literature from 2015 dealing with gastric and enterohepatic non‐Helicobacter pylori Helicobacter species (NHPH). A summary of the gastric microbiota interactions with H. pylori is also presented. An extensive number of studies were published during the last year and have led to a better understanding of the pathogenesis of infections with NHPH. These infections are increasingly reported in human patients, including infections with H. cinaedi, mainly characterized by severe bacteremia. Whole‐genome sequencing appears to be the most reliable technique for identification of NHPH at species level. Presence of NHPH in laboratory animals may influence the outcome of experiments, making screening and eradication desirable. Vaccination based on UreB proteins or bacterial lysate with CCR4 antagonists as well as oral glutathione supplementation may be promising strategies to dampen the pathogenic effects associated with gastric NHPH infections. Several virulent factors such as outer membrane proteins, phospholipase C‐gamma 2, Bak protein, and nickel‐binding proteins are associated with colonization of the gastric mucosae and development of gastritis. The development of high‐throughput sequencing has led to new insights in the gastric microbiota composition and its interaction with H. pylori. Alterations in the gastric microbiota caused by the pH‐increasing effect of a H. pylori infection may increase the risk for gastric cancer.
Conservation genetics of an endangered grassland butterfly (Oarisma poweshiek) reveals historically high gene flow despite recent and rapid range loss
Authors: Saarinen Emily V. , Reilly Patrick F. , Austin James D.
Published: August 2016

In poorly dispersing species gene flow can be facilitated when suitable habitat is widespread, allowing for increased dispersal between neighbouring locations. The Poweshiek skipperling [Oarisma poweshiek (Parker)], a federally endangered butterfly, has undergone a rapid, recent demographic decline following the loss of tallgrass prairie and fen habitats range wide. The loss of habitat, now restricted geographic range, and poor dispersal ability have left O. poweshiek at increased risk of extinction.

We studied the population genetics of six remaining populations of O. poweshiek in order to test the hypothesis that gene flow was historically high despite limited long‐distance dispersal capability. Utilising nine microsatellite loci developed by PacBio sequencing, we tested for patterns of isolation by distance, low population genetic structure and alternative gene flow models.

Populations from southern Manitoba, Canada to the Lower Peninsula of Michigan, USA are only weakly genetically differentiated despite having low diversity. We found no support for isolation by distance, and Bayesian estimates of historical gene flow support our hypothesis that high levels of gene flow previously connected populations from Michigan to Wisconsin.

Prairie grasslands have been reduced tremendously over the past century, but the low mobility of O. poweshiek suggests that rapid loss of populations over the past decade cannot be simply explained by fragmentation of habitat.

As a species at high risk of extinction, understanding historical processes of gene flow will allow for informed management decisions with respect to head‐starting individuals for population reintroductions and for conserving networks of habitat that will allow for high levels of gene flow.
5‐HT2A receptor enhancement of contractile activity of the porcine urothelium and lamina propria
Authors: Moro Christian , Edwards Lily , Chess‐Williams Russ
Published: August 2016

Objectives

To examine the effect of 5‐hydroxytryptamine (5‐HT; serotonin) on the contractile properties of the urothelium and lamina propria, as a better understanding of bladder physiology might aid the development of new treatments.

Methods

Strips of porcine urothelium and lamina propria were suspended in gassed Krebs‐bicarbonate solution, and cumulative concentration–response curves for 5‐HT were generated in the absence and presence of 5‐HT antagonists, Nω‐nitro‐l‐arginine and indomethacin. Responses to α‐methyl‐5‐HT were also examined.

Results

Strips of urothelium/lamina propria developed spontaneous contractions, whereas the addition of 5‐HT induced concentration‐dependent increases in contractile tone with maximal contractions of 50.43 ± 2.78 mN/g tissue weight (n = 100). Tonic contractions to 5‐HT were unchanged in the presence of Nω‐nitro‐l‐arginine (100 μmol/L) or indomethacin (5 μmol/L). Selective concentrations of the antagonists methiothepin (5‐HT1&2, 100 nmol/L), RS102221 (5‐HT2C, 30 nmol/L), ondansetron (5‐HT3, 30 nmol/L), GR113808, (5‐HT4, 100 nmol/L), SB699551 (5‐HT5, 10 nmol/L), SB399885 (5‐HT6, 100 nmol/L) and SB269970 (5‐HT7, 10 nmol/L) did not influence responses to 5‐HT. However, the 5‐HT2A antagonist, ketanserin (30–300 μmol/L), caused a shift of the 5‐HT curve yielding an affinity estimate of 7.9.

Conclusions

The results show that contractile responses of the urothelium/lamina propria to 5‐HT are predominantly mediated through the 5‐HT2A receptor.
Does primary care diabetes management provided to Medicare patients differ between primary care physicians and nurse practitioners?
Authors: Lutfiyya May Nawal , Tomai Lisa , Frogner Bianca , Cerra Frank , Zismer Daniel , Parente Stephen
Published: August 2016

Aims

The aim of this study was to answer the overall question: Does primary care diabetes management for Medicare patients differ in scope and outcomes by provider type (physician or nurse practitioner)?

Background

In the USA as well as globally, there is a pressing need to address high healthcare costs while improving healthcare outcomes. Primary health care is one area where healthcare reform has received considerable attention, in part because of continued projections of primary care physician shortages. Many argue that nurse practitioners are one solution to ease the consequences of the projected shortage of primary care physicians in the USA as well as other developed countries.

Design

Cross‐sectional quantitative analysis of 2012 Medicare claims data.

Methods

A 5% Standard Analytic File of 2012 Medicare claims data for beneficiaries with Type 2 diabetes were analysed. A medical productivity index was used to stratify patients as healthiest and least healthy who were seen by either nurse practitioners only or primary care physicians exclusively. Included in the analyses were health services utilization, health outcomes and healthcare cost variables.

Results

The patients in the nurse practitioner only group, overall and stratified by medical productivity index status, had significantly improved outcomes compared with all primary care physician provider groups regarding healthcare services utilization, patient health outcomes and healthcare costs.

Conclusions

These findings inform current healthcare workforce conversations regarding healthcare quality, outcomes and costs. Our results suggest nurse practitioner engagement in chronic care patient management in primary care settings is associated with lower cost and better quality health care.
Apremilast, an oral phosphodiesterase 4 inhibitor, improves patient‐reported outcomes in the treatment of moderate to severe psoriasis: results of two phase III randomized, controlled trials
Authors: Thaçi D. , Kimball A. , Foley P. , Poulin Y. , Levi E. , Chen R. , Feldman S.R.
Published: August 2016

Background

Apremilast, an oral phosphodiesterase 4 inhibitor, has an acceptable safety profile and is effective for treatment of plaque psoriasis and psoriatic arthritis.

Objectives

To evaluate the impact of apremilast on health‐related quality of life (HRQOL), general functioning and mental health using patient‐reported outcome (PRO) assessments among patients with moderate to severe plaque psoriasis in the ESTEEM 1 and 2 trials.

Methods

A total of 1255 patients were randomized (2 : 1) to apremilast 30 mg BID or placebo for 16 weeks; all received apremilast through Week 32. PRO assessments included the Dermatology Life Quality Index (DLQI), 36‐Item Short‐Form Health Survey version 2 mental/physical component summary scores (SF‐36v2 MCS/PCS), Patient Health Questionnaire‐8 (PHQ‐8), EuroQol‐5D (EQ‐5D) and Work Limitations Questionnaire‐25 (WLQ‐25). Post hoc analyses examined relationships between Psoriasis Area and Severity Index (PASI) scores and PHQ‐8 in the apremilast‐treated population at Week 16.

Results

Treatment with apremilast improved all HRQOL PROs at Week 16 (vs. placebo), except the SF‐36v2 PCS, and improvements were sustained through Week 32. Mean DLQI and SF‐36v2 MCS improvements exceeded minimal clinically important differences. Changes at Week 16 in PHQ‐8 and PASI were weakly correlated, and only 35.8% of patients who achieved a ≥75% reduction from baseline in PASI score (PASI‐75) with apremilast treatment also achieved PHQ‐8 scores of 0–4.

Conclusions

Apremilast led to improvements in HRQOL PROs vs. placebo in patients with moderate to severe plaque psoriasis.
Filling the gaps and finding our way: family carers navigating the healthcare system to access physical health services for the people they care for
Authors: Happell Brenda , Wilson Karen , Platania‐Phung Chris , Stanton Robert
Published: August 2016

Aims and Objectives

To elicit the perspectives of carers of people with mental illness regarding access to, and experience with, physical healthcare services for mental health consumers.

Background

People diagnosed with mental illness have increased risks of physical illness and earlier death, problems able to be addressed through better physical health services. Carers of people with mental illness play a significant role in the mental healthcare system yet research examining their views is lacking.

Design

Qualitative exploratory.

Methods

In‐depth interviews were conducted with 13 mental health carers. They were asked to describe their views and experiences pertaining to the physical health and availability of physical health care for the people they care for. Data were analysed using the framework of Braun and Clarke.

Results

Analysis of carer responses identified two important themes: responsiveness and access, and a shortage of care coordination. Carers felt alienated from physical healthcare providers and were compelled to fill gaps in available care through persistence in ensuring access to physical healthcare services.

Conclusions

The findings identify carers as key stakeholders in the physical health care for the people they care for. Their involvement in accessing and coordinating care provides vital perspective on health service capacity, which requires further consideration in the practice and research domains.

Relevance to clinical practice

Carers of people diagnosed with mental illness are crucial to the effective delivery of mental health services. Their perspectives must be central to their research agenda and contribute to the development of initiatives to improve clinical practice and promote improved physical health care.
Perceived social support following percutaneous coronary intervention is a crucial factor in patients with coronary heart disease
Authors: Kähkönen Outi , Kankkunen Päivi , Miettinen Heikki , Lamidi Marja‐Leena , Saaranen Terhi
Published: August 2016

Aims and objectives

To describe perceived social support among patients with coronary heart disease following percutaneous coronary intervention.

Background

A low level of social support is considered a risk factor for coronary heart disease in healthy individuals and reduces the likelihood that people diagnosed with coronary heart disease will have a good prognosis.

Design

A descriptive cross‐sectional study.

Methods

A survey of 416 patients was conducted in 2013. A self‐report instrument, Social Support of People with Coronary Heart Disease, was used. The instrument comprises three dimensions of social support: informational, emotional, functional supports and 16 background variables. Data were analysed using descriptive statistics, factor analysis, mean sum variables and multivariate logistic regression.

Results

Perceived informational support was primarily high, but respondents’ risk factors were not at the target level. The weakest items of informational support were advice on physical activity, continuum of care and rehabilitation. Regarding the items of emotional support, support from other cardiac patients was the weakest. The weakest item of functional support was respondents’ sense of the healthcare professionals’ care of patients coping with their disease. Background variables associated with perceived social support were gender, marital status, level of formal education, profession, physical activity, duration of coronary heart disease and previous myocardial infarction.

Conclusions

Healthcare professionals should pay extra attention to women, single patients, physically inactive patients, those demonstrating a lower level of education, those with a longer duration of CHD, and respondents without previous acute myocardial infarction. Continuum of care and counselling are important to ensure especially among them.

Relevance to clinical practice

This study provides evidence that healthcare professionals should be more aware of the individual needs for social support among patients with coronary heart disease after percutaneous coronary intervention.
Immediate implant placement and provisionalisation in the aesthetic zone
Authors: Van Nimwegen W. G. , Goené R. J. , Van Daelen A. C. L. , Stellingsma K. , Raghoebar G. M. , Meijer H. J. A.
Published: August 2016

The aim of this retrospective study was to assess the outcome of immediate single‐tooth implant placement and provisionalisation in the aesthetic zone regarding hard and soft peri‐implant tissue parameters and patient‐related outcome measures in a private practice. All consecutively treated patients with single‐tooth immediate implant placement and provisionalisation between the period 1 January 2006 and 1 April 2013 in a referral practice in Amsterdam, the Netherlands, were included in the study. Fifty‐one patients of a total of 64 could be examined at follow‐up (Tfollow‐up). Radiographs were present from implant placement (Tplacement), after definitive crown placement (Tdefinitive), and new radiographs were taken at the follow‐up appointment (Tfollow‐up). Next to this, soft tissue parameters, patients’ satisfaction and professionals’ aesthetic scores were measured at Tfollow‐up. Implant survival was 96·9% after a mean follow‐up period of 4 years following implant placement. At definitive crown placement, mean marginal bone‐level loss was 0·25 mm (SD 0·19). Mean marginal bone‐level loss following definitive crown placement was 0·06 mm (SD 0·10) (Tdefinitive to Tfollow‐up) after a mean follow‐up period of 4 years. Plaque index, bleeding index and gingival index scores were low. Patients’ satisfaction was rated very high: 9·0 (SD 0·7). Professionals aesthetic score was 16·49 (SD 1·86). From this study can be concluded that immediate placement of implants followed by immediate provisionalisation resulted in a high survival rate, minimum peri‐implant bone loss, very good aesthetics and satisfied patients after a mean follow‐up period of 4 years.
Introspection and Necessity
Authors: Stoljar Daniel
Published: August 2016

What is the connection between being in a conscious mental state and believing that you yourself are currently in that state? On the one hand, it is natural to think that this connection is, or involves, a necessary connection of some sort. On the other hand, it is hard to know what the nature of this necessary connection is. For there are plausible arguments according to which this connection is not metaphysically necessary, not rationally necessary, and not merely naturally necessary. If these arguments are correct, and if these options are exhaustive, while there is a necessary connection between a conscious state and the belief that you are in it, there is apparently no necessary connection it could be! This paper sets out this problem—the necessary connection problem, I will call it—and defends and explores a novel proposal about how to solve it.
Wood traits related to size and life history of trees in a Panamanian rainforest
Authors: Hietz Peter , Rosner Sabine , Hietz‐Seifert Ursula , Wright S. Joseph
Published: August 2016

Wood structure differs widely among tree species and species with faster growth, higher mortality and larger maximum size have been reported to have fewer but larger vessels and higher hydraulic conductivity (Kh). However, previous studies compiled data from various sources, often failed to control tree size and rarely controlled variation in other traits.

We measured wood density, tree size and vessel traits for 325 species from a wet forest in Panama, and compared wood and leaf traits to demographic traits using species‐level data and phylogenetically independent contrasts.

Wood traits showed strong phylogenetic signal whereas pairwise relationships between traits were mostly phylogenetically independent. Trees with larger vessels had a lower fraction of the cross‐sectional area occupied by vessel lumina, suggesting that the hydraulic efficiency of large vessels permits trees to dedicate a larger proportion of the wood to functions other than water transport.

Vessel traits were more strongly correlated with the size of individual trees than with maximal size of a species. When individual tree size was included in models, Kh scaled positively with maximal size and was the best predictor for both diameter and biomass growth rates, but was unrelated to mortality.
Chloroplast quality control – balancing energy production and stress
Authors: Woodson Jesse D.
Published: August 2016

All organisms require the ability to sense their surroundings and adapt. Such capabilities allow them to thrive in a wide range of habitats. This is especially true for plants, which are sessile and have to be genetically equipped to withstand every change in their environment. Plants and other eukaryotes use their energy‐producing organelles (i.e. mitochondria and chloroplasts) as such sensors. In response to a changing cellular or external environment, these organelles can emit ‘retrograde’ signals that alter gene expression and/or cell physiology. This signaling is important in plants, fungi, and animals and impacts diverse cellular functions including photosynthesis, energy production/storage, stress responses, growth, cell death, ageing, and tumor progression. Originally, chloroplast retrograde signals in plants were known to lead to the reprogramming of nuclear transcription. New research, however, has pointed to additional posttranslational mechanisms that lead to chloroplast regulation and turnover in response to stress. Such mechanisms involve singlet oxygen, ubiquitination, the 26S proteasome, and cellular degradation machinery.

Contents

Summary
36

I.
Introduction
36

II.
Retrograde signaling from the chloroplast to the nucleus
37

III.
Chloroplast quality control – a new kind of retrograde signal?
37

IV.
Roles of ubiquitin in chloroplast signaling and stress
38

V.
Singlet oxygen as a specific marker for chloroplast stress
39

VI.
How are chloroplasts degraded?
40

VII.
Conclusions/outlook
40

Acknowledgements
40

References
40
Intraoperative management and early postoperative outcomes of pediatric renal transplants
Authors: Taylor Katherine , Kim Wooheon Thomas , Maharramova Malak , Figueroa Victor , Ramesh Smruthi , Lorenzo Armando
Published: August 2016

Introduction

Smaller children are presenting for renal transplantation as the treatment of choice for end‐stage renal disease. Adult donor organs are more successful than pediatric deceased donor organs. An adult kidney may sequester ~75% of the circulating volume of a 5 year‐old child and requires significantly increased cardiac output to maintain renal perfusion. Treatment includes volume, inotropic or vasopressor agents, or central neuroaxial blockade for sympatholysis.

We describe the perioperative anesthestic management as a guide to clinical outcomes.

Methods

A retrospective chart review of renal transplant patients between 2006 and 2014 was performed. We recorded patient demographics, surgical and anesthetic factors and postoperative outcome.

Results

One hundred and fifty‐six children underwent renal transplantation, of which 38% were from living donors. There were 99/156 (63.5%) males. Median age was 10 years (range 1–17 years) and the mean weight was 36.2 kg (sd 20.6 kg; range 7.6–109.6 kg). There were 36 children ≤5 years of age and 14 children ≤2 years of age. One hundred and nineteen (77%) were dialysis dependent.

Pharmacological support to increase renal perfusion included mannitol in 95%, and dopamine in 83%. Furosemide was used in 82% of cases. Inotropic therapy continued into the postoperative period in 34%. Radiological pulmonary edema was diagnosed in 33% and clinical pulmonary edema in 7%. Intraoperative use of dopamine delayed the time to creatinine nadir in all grafts (9.5 days vs 6.5 days, P = 0.04) and in deceased donor grafts (12.9 vs 7.4 days, P = 0.007). Patients who received dopamine had no significant difference in central venous pressure (CVP) preclamp removal, 14 mmHg vs 11.5 mmHg (P = 0.12) but a higher CVP after clamp removal, 14.3 mmHg vs 11.8 mmHg (P = 0.003).

Conclusion

Dopamine use was common and was an independent risk factor for delayed time to creatinine nadir. Many different agents were used to enhance renal perfusion. The ‘supra‐physiological’ hemodynamics resulted in pulmonary edema in 33% of patients.
The Construction of Hinduism in America
Authors: Altman Michael J.
Published: August 2016

Yet, there has never been a unified or singular Hinduism in America. Rather, the story of Hinduisms in America provides an important example for the ways a religious tradition is imagined in America. In the 18th and 19th century, Americans described religion in India as ‘heathenism’, ‘Hindoo religion’, ‘Hindu religion’, and ‘Brahmanism’. By the end of the 19th century, figures like Swami Vivekanada brought the idea of ‘Hinduism’, a world religion, to America. In the 20th century, Hindu immigrants from South Asia began to build temples and practice their own forms of Hinduism throughout the United States.
Revisiting the Memory‐Based Processing Approach to Common Ground
Authors: Horton William S. , Gerrig Richard J.
Published: August 2016

Horton and Gerrig (2005a) outlined a memory‐based processing model of conversational common ground that provided a description of how speakers could both strategically and automatically gain access to information about others through domain‐general memory processes acting over ordinary memory traces. In this article, we revisit this account, reviewing empirical findings that address aspects of this memory‐based model. In doing so, we also take the opportunity to clarify what we believe this approach implies about the cognitive psychology of common ground, and just as important, what it does not imply. We also highlight related areas of research demonstrating how general cognitive processes can constrain access to relevant knowledge in ways that shape both language production and comprehension.
EU Trade Regulation for Baby Food: Protecting Health or Trade?
Authors: DeMaria Federica , Drogue Sophie
Published: August 2016

This paper explores the effect of European Union (EU) food safety regulations on EU imports of baby food. Pesticides and contaminants contribute to various health problems. Children are more vulnerable to the dangers of pesticides and contaminants because as soon as they start eating solids, they consume a limited number of food items, most of which are fruits and vegetables. To protect the health of the most vulnerable part of the population, the EU regulations stipulate that no more than 0.01 mg/kg of any single pesticide residue is permitted in baby food. In this respect, the EU differs from most of its trading partners, the majority of which do not differentiate food safety regulations according to the age of the consumer. The purpose of this paper is to compare the EU regulations on maximum residue limits of pesticides to those of its major competitors through a severity index. This index is then introduced into a gravity equation to assess the impact on EU imports of baby food. We find that the EU regulation had a negative impact on the volume of trade but a positive one on the probability of setting up new trade relationships.
Caloric restriction selectively reduces the GABAergic phenotype of mouse hypothalamic proopiomelanocortin neurons
Authors: Jarvie Brooke C. , King Connie M. , Hughes Alexander R. , Dicken Matthew S. , Dennison Christina S. , Hentges Shane T.
Published: August 2016

Key points

Hypothalamic proopiomelanocortin (POMC) neurons release peptide products that potently inhibit food intake and reduce body weight.

These neurons also release the amino acid transmitter GABA, which can inhibit downstream neurons.

Although the release of peptide transmitters from POMC neurons is regulated by energy state, whether similar regulation of GABA release might occur had not been examined.

The present results show that the GABAergic phenotype of POMC neurons is decreased selectively by caloric deficit and not altered by high‐fat diet or stress.

The fact the GABAergic phenotype of POMC neurons is sensitive to energy state suggests a dynamic physiological role for this transmitter and highlights the importance of determining the functional consequence of GABA released from POMC neurons in terms of the regulation of normal energy balance.

In addition to peptide transmitters, hypothalamic neurons, including proopiomelanocortin (POMC) and agouti‐related peptide (AgRP) neurons, also release amino acid transmitters that can alter energy balance regulation. While recent studies show that the GABAergic nature of AgRP neurons is increased by caloric restriction, whether the GABAergic phenotype of POMC neurons is also regulated in an energy‐state‐dependent manner has not been previously examined. The present studies used fluorescence in situ hybridization to detect Gad1 and Gad2 mRNA in POMC neurons, as these encode the glutamate decarboxylase enzymes GAD67 and GAD65, respectively. The results show that both short‐term fasting and chronic caloric restriction significantly reduce the percentage of POMC neurons expressing Gad1 mRNA in both male and female mice, with less of an effect on Gad2 expression. Neither acute nor chronic intermittent restraint stress altered Gad1 expression in POMC neurons. Maintenance on a high‐fat diet also did not affect the portion POMC neurons expressing Gad1, suggesting that the GABAergic phenotype of POMC neurons is particularly sensitive to energy deficit. Because changes in Gad1 expression have been previously shown to correlate with altered terminal GABA release, fasting is likely to cause a decrease in GABA release from POMC neurons. Altogether, the present results show that the GABAergic nature of POMC neurons can be dynamically regulated by energy state in a manner opposite to that in AgRP neurons and suggest the importance of considering the functional role of GABA release in addition to the peptide transmitters from POMC neurons.
Direct X-Ray Imaging as a Tool for Understanding Multiphysics Phenomena in Energy Storage
Authors: Nelson George J. , van Zandt Zachary K. , Jibhakate Piyush D.
Published: August 2016

The lithium-ion battery (LIB) has emerged as a key energy storage device for a wide range of applications, from consumer electronics to transportation. While LIBs have made key advancements in these areas, limitations remain for Li-ion batteries with respect to affordability, performance, and reliability. These challenges have encouraged the exploration for more advanced materials and novel chemistries to mitigate these limitations. The continued development of Li-ion and other advanced batteries is an inherently multiscale problem that couples electrochemistry, transport phenomena, mechanics, microstructural morphology, and device architecture. Observing the internal structure of batteries, both ex situ and during operation, provides a critical capability for further advancement of energy storage technology. X-ray imaging has been implemented to provide further insight into the mechanisms governing Li-ion batteries through several 2D and 3D techniques. Ex situ imaging has yielded microstructural data from both anode and cathode materials, providing insight into mesoscale structure and composition. Furthermore, since X-ray imaging is a nondestructive process studies have been conducted in situ and in operando to observe the mechanisms of operation as they occur. Data obtained with these methods has also been integrated into multiphysics models to predict and analyze electrode behavior. The following paper provides a brief review of X-ray imaging work related to Li-ion batteries and the opportunities these methods provide for the direct observation and analysis of the multiphysics behavior of battery materials.
Adaptive Augmenting Control Design for Time-Varying Polytopic Systems
Authors: Mahdianfar Hessam , Prempain Emmanuel
Published: August 2016

To increase the performance of closed-loop controlled systems in off-nominal conditions and in the presence of inevitable faults and uncertainties, a systematic approach based on robust convex optimization for adaptive augmenting control design is discussed in this paper. More specifically, this paper addresses the problem of adaptive augmenting controller (AAC) design for systems with time-varying polytopic uncertainty. First, a robust state-feedback controller is designed via robust convex optimization as a baseline controller. The closed-loop polytopic system with the baseline controller is considered as the desired time-varying reference model for the design of a direct state-feedback adaptive controller. Next using Lyapunov arguments, global stability of combined robust baseline and adaptive augmenting controllers is established. Furthermore, it is proved that tracking error converges to zero asymptotically. A case study for a generic nonminimum phase nonlinear pitch-axis missile autopilot is conducted. Simulation tests are performed to evaluate stability and performance of nonlinear time-varying closed-loop system in the presence of uncertainties in pitching moment and normal force coefficients, and unmodeled time delays. In addition, results of the simulations indicate satisfactory robustness in case of severe loss of control effectiveness event.
Unsteady Flow Phenomena in Turbine Rim Seals
Authors: Beard Paul F. , Gao Feng , Chana Kam S. , Chew John
Published: August 2016

While turbine rim sealing flows are an important aspect of turbomachinery design, affecting turbine aerodynamic performance and turbine disk temperatures, the present understanding and predictive capability for such flows is limited. The aim of the present study is to clarify the flow physics involved in rim sealing flows and to provide high-quality experimental data for use in evaluation of computational fluid dynamics (CFD) models. The seal considered is similar to a chute seal previously investigated by other workers, and the study focuses on the inherent unsteadiness of rim seal flows, rather than unsteadiness imposed by the rotating blades. Unsteady pressure measurements from radially and circumferentially distributed transducers are presented for flow in a rotor–stator disk cavity and the rim seal without imposed external flow. The test matrix covered ranges in rotational Reynolds number, Re∅, and nondimensional flow rate, Cw, of 2.2–3.0 × 106 and 0–3.5 × 103, respectively. Distinct frequencies are identified in the cavity flow, and detailed analysis of the pressure data associates these with large-scale flow structures rotating about the axis. This confirms the occurrence of such structures as predicted in previously published CFD studies and provides new data for detailed assessment of CFD models.
Sci‐Thur PM – Brachytherapy 05: Surface Collimation Applied to Superficial Flap High Dose‐Rate Brachytherapy
Authors: Liu Derek , Sabondjian Eric , Lawrence Kailin , Sankreacha Raxa
Published: August 2016

Purpose:

To apply surface collimation for superficial flap HDR skin brachytherapy utilizing common clinical resources and to demonstrate the potential for OAR dose reduction within a clinically relevant setting.

Methods:

Two phantom setups were used. 3 mm lead collimation was applied to a solid slab phantom to determine appropriate geometries relating to collimation and dwell activation. The same collimation was applied to the temple of an anthropomorphic head phantom to demonstrate lens dose reduction. Each setup was simulated and planned to deliver 400 cGy to a 3 cm circular target to 3 mm depth. The control and collimated irradiations were sequentially measured using calibrated radiochromic films.

Results:

Collimation for the slab phantom attenuated the dose beyond the collimator opening, decreasing the fall‐off distances by half and reducing the area of healthy skin irradiated. Target coverage can be negatively impacted by a tight collimation margin, with the required margin approximated by the primary beam geometric penumbra.

Surface collimation applied to the head phantom similarly attenuated the surrounding normal tissue dose while reducing the lens dose from 84 to 68 cGy. To ensure consistent setup between simulation and treatment, additional QA was performed including collimator markup, accounting for collimator placement uncertainties, standoff distance verification, and in vivo dosimetry.

Conclusions:

Surface collimation was shown to reduce normal tissue dose without compromising target coverage. Lens dose reduction was demonstrated on an anthropomorphic phantom within a clinical setting. Additional QA is proposed to ensure treatment fidelity.
Poster ‐ 11: Radiation barrier thickness calculations for the GammaPod
Authors: La Russa Daniel , Vandervoort Eric , Wilkins David
Published: August 2016

A consortium of radiotherapy centers in North America is in the process of evaluating a novel new 60Co teletherapy device, called the GammaPod™ (Xcision Medical Systems, Columbia Maryland), designed specifically for breast SBRT. The GammaPod consists of 36 collimated 60Co sources with a total activity of 4320 Ci. The sources are housed in a hemispherical source carrier that rotates during treatment to produce a cylindrically symmetric cone of primary beam spanning 16° – 54° degrees from the horizontal. This unique beam geometry presents challenges when designing or evaluating room shielding for the purposes of meeting regulatory requirements, and for ensuring the safety of staff and the public in surrounding areas. Conventional methods for calculating radiation barrier thicknesses have been adapted so that barrier transmission factors for the GammaPod can be determined from a few relevant distances and characteristics of the primary beam. Simple formalisms have been determined for estimating shielding requirements for primary radiation (with a rotating and non‐rotating source carrier), patient‐scattered radiation, and leakage radiation. When making worst case assumptions, it was found that conventional barrier thicknesses associated with linac treatment suites are sufficient for shielding all sources of radiation from the GammaPod.
Poster ‐ 16: Time‐resolved diode dosimetry for in vivo proton therapy range verification: calibration through numerical modeling
Authors: Toltz Allison , Hoesl Michaela , Schuemann Jan , Seuntjens Jan , Lu Hsiao‐Ming , Paganetti Harald
Published: August 2016

Purpose:

A method to refine the implementation of an in vivo, adaptive proton therapy range verification methodology was investigated. Simulation experiments and in‐phantom measurements were compared to validate the calibration procedure of a time‐resolved diode dosimetry technique.

Methods:

A silicon diode array system has been developed and experimentally tested in phantom for passively scattered proton beam range verification by correlating properties of the detector signal to the water equivalent path length (WEPL). The implementation of this system requires a set of calibration measurements to establish a beam‐specific diode response to WEPL fit for the selected ‘scout’ beam in a solid water phantom. This process is both tedious, as it necessitates a separate set of measurements for every ‘scout’ beam that may be appropriate to the clinical case, as well as inconvenient due to limited access to the clinical beamline. The diode response to WEPL relationship for a given ‘scout’ beam may be determined within a simulation environment, facilitating the applicability of this dosimetry technique. Measurements for three ‘scout’ beams were compared against simulated detector response with Monte Carlo methods using the Tool for Particle Simulation (TOPAS).

Results:

Detector response in water equivalent plastic was successfully validated against simulation for spread out Bragg peaks of range 10 cm, 15 cm, and 21 cm (168 MeV, 177 MeV, and 210 MeV) with adjusted R2 of 0.998.

Conclusion:

Feasibility has been shown for performing calibration of detector response for a given ‘scout’ beam through simulation for the time resolved diode dosimetry technique.
Poster ‐ 20: Detector selection for commissioning of a Monte Carlo based electron dose calculation algorithm
Authors: Anusionwu Princess , Alpuche Aviles Jorge E. , Pistorius Stephen
Published: August 2016

Objective:

Commissioning of a Monte Carlo based electron dose calculation algorithm requires percentage depth doses (PDDs) and beam profiles which can be measured with multiple detectors. Electron dosimetry is commonly performed with cylindrical chambers but parallel plate chambers and diodes can also be used. The purpose of this study was to determine the most appropriate detector to perform the commissioning measurements.

Methods:

PDDs and beam profiles were measured for beams with energies ranging from 6 MeV to 15 MeV and field sizes ranging from 6 cm × 6 cm to 40 cm × 40 cm. Detectors used included diodes, cylindrical and parallel plate ionization chambers. Beam profiles were measured in water (100 cm source to surface distance) and in air (95 cm source to detector distance).

Results:

PDDs for the cylindrical chambers were shallower (1.3 mm averaged over all energies and field sizes) than those measured with the parallel plate chambers and diodes. Surface doses measured with the diode and cylindrical chamber were on average larger by 1.6 % and 3% respectively than those of the parallel plate chamber. Profiles measured with a diode resulted in penumbra values smaller than those measured with the cylindrical chamber by 2 mm.

Conclusion:

The diode was selected as the most appropriate detector since PDDs agreed with those measured with parallel plate chambers (typically recommended for low energies) and results in sharper profiles. Unlike ion chambers, no corrections are needed to measure PDDs, making it more convenient to use.
Poster ‐ 22: Retrospective analysis of portal dosimetry based QA of Prostate VMAT Plans
Authors: Badu Shyam , Darko Johnson , Fleck Andre , Osei Ernest
Published: August 2016

Purpose:

The purpose of this study is to retrospectively analyze the portal dosimetry based quality assurance of prostate VMAT plans.

Methods:

Our standard quality assurance of VMAT treatment plans are performed using EPID installed on Varian TrueBeam Linac. In our current study we analyzed 84 prostate pretreatment VMAT plans. All plans consisted of two arcs, 7800cGy in 39 fractions with a 6MV beam. For each of these VMAT plans, the measured fluence for each arc is compared with the reference fluence using gamma index analysis.

Results:

We have compared the gamma passing rates for three criteria; 3%/3mm, 2%/2mm and 1%/1mm. Out of 168 arcs measured, the number below the gamma passing rate 95% using the area, Field+1cm, are 0, 2, and 124 for 3%/3mm, 2%/2mm and 1%/1mm criteria respectively. Corresponding numbers for MLC CIAO are 0, 2, and 139 respectively. The average gamma passing rate for all arcs measured using Field+1cm are 99.9±0.4, 99.6±1.2, and 90.9±6.5 for 3%/3mm, 2%/2mm and 1%/1mm respectively. Similarly if the MLC CIAO area is analyzed, a passing rate of 99.9±0.2, 99.2±1.2 and 87.2±8.5 respectively was observed. The average of the maximum gamma was also found to increase with tighter criteria.

Conclusion:

Analysis of prostate VMAT quality assurance plans indicate that the gamma passing rate is sensitive to the criteria and the area analyzed.
Poster ‐ 23: Dosimetric Characterization and Transferability of an Accessory Mounted Mini‐Beam Collimator
Authors: Davis William , Crewson Cody , Alexander Andrew , Cranmer‐Sargison Gavin , Kundapur Vijayananda
Published: August 2016

Objective:

The dosimetric characterization of an accessory‐mounted mini‐beam collimator across three beam matched linear accelerators.

Materials and Methods:

Percent depth dose and profiles were measured for the open and mini‐beam collimated fields. The average beam quality and peak‐to‐valley dose ratio (PVDR), the ratio of average peak dose to average valley dose, were obtained from these measurements. The open field relative output and the mini‐beam collimator factor, the ratio of the mini‐beam dose to open field dose at the beam center, were measured for square fields of side 2, 3, 4, and 5 cm. Mini‐beam output as a function of collimator inclination angle relative to the central axis was also investigated.

Results and Discussion:

Beam quality for both the open and mini‐beam collimated fields agreed across all linacs to within ±1.0%. The PVDR was found to vary by up to ±6.6% from the mean. For the 2, 3, and 4 cm fields the average open field relative output with respect to the 5 cm field was 0.874±0.4%, 0.921±0.3%, and 0.962±0.1%. The average collimator factors were 0.450±3.9%, 0.443±3.9%, 0.438±3.9%, and 0.434±3.9%. A decrease in collimator factor greater than 7% was found for an inclination angle change of 0.09°.

Conclusion:

The mini‐beam collimator has revealed a difference between the three linacs not apparent in the open field data, yet transferability can still be attained through thorough dosimetric characterization.
Poster ‐ 26: Electronic Waiting Room Management for a busy Cancer Centre
Authors: Kildea John , Hijal Tarek
Published: August 2016

We describe an electronic waiting room management system that we have developed and deployed in our cancer centre. Our system connects with our electronic medical records systems, gathers data for a machine learning algorithm to predict future patient waiting times, and is integrated with a mobile phone app. The system has been in operation for over nine months and has led to reduced lines, calmer waiting rooms and overwhelming patient and staff satisfaction.
Poster ‐ 32: Atlas Selection for Automated Segmentation of Pelvic CT for Prostate Radiotherapy
Authors: Mallawi Abrar , Farrell TomTom , Diamond Kevin‐Ross , Wierzbicki Marcin
Published: August 2016

Atlas based‐segmentation has recently been evaluated for use in prostate radiotherapy. In a typical approach, the essential step is the selection of an atlas from a database that the best matches of the target image. This work proposes an atlas selection strategy and evaluate it impacts on final segmentation accuracy.

Several anatomical parameters were measured to indicate the overall prostate and body shape, all of these measurements obtained on CT images. A brute force procedure was first performed for a training dataset of 20 patients using image registration to pair subject with similar contours; each subject was served as a target image to which all reaming 19 images were affinity registered. The overlap between the prostate and femoral heads was quantified for each pair using the Dice Similarity Coefficient (DSC). Finally, an atlas selection procedure was designed; relying on the computation of a similarity score defined as a weighted sum of differences between the target and atlas subject anatomical measurement.

The algorithm ability to predict the most similar atlas was excellent, achieving mean DSCs of 0.78 ± 0.07 and 0.90 ± 0.02 for the CTV and either femoral head. The proposed atlas selection yielded 0.72 ± 0.11 and 0.87 ± 0.03 for CTV and either femoral head. The DSC obtained with the proposed selection method were slightly lower than the maximum established using brute force, but this does not include potential improvements expected with deformable registration. The proposed atlas selection method provides reasonable segmentation accuracy.