bluuebunny/crossref_metadata_2025 huggingface dataset:
A multi‐model framework to estimate perfusion parameters using contrast‐enhanced ultrasound imaging
Authors: Akhbardeh Alireza , Sagreiya Hersh , El Kaffas Ahmed , Willmann Jürgen K. , Rubin Daniel L.
Published: December 2018

Purpose

Contrast‐enhanced ultrasound imaging has expanded the diagnostic potential of ultrasound by enabling real‐time imaging and quantification of tissue perfusion. Several perfusion models and curve fitting methods have been developed to quantify the temporal behavior of tracer signal and standardize perfusion quantification. While the least‐squares approach has traditionally been applied for curve fitting, it can be inadequate for noisy and complex data. Moreover, previous research suggests that certain perfusion models may be more relevant depending on the organ or tissue imaged. We propose a multi‐model framework to select the most appropriate perfusion model and curve fitting method for each diagnostic application.

Methods

Our multi‐model approach uses a system identification method, which estimates perfusion parameters from the model with the best fit to a given time–intensity curve. We compared current perfusion quantification methods that use a single perfusion model and curve fitting method and our proposed multi‐model framework on bolus 3D dynamic contrast‐enhanced ultrasound (DCE‐US) in vivo images obtained in mice implanted with a colon cancer, as well as on simulation data. The quality of fit in estimating perfusion parameters was evaluated using the Spearman correlation coefficient, the coefficient of determination (R2), and the normalized root‐mean‐square error (NRMSE) to ensure that the multi‐model framework finds the best perfusion model and curve fitting algorithm.

Results

Our multi‐model framework outperforms conventional single perfusion model approaches with least‐squares optimization, providing more robust perfusion parameter estimation. R2 and NRMSE are 0.98 and 0.18, respectively, for our proposed method. By comparison, the performance of the traditional approach is much more dependent upon the selection of the appropriate model. The R2 and NRMSE are 0.91 and 0.31, respectively.

Conclusions

The proposed multi‐model framework for perfusion modeling outperforms the current approach of single perfusion modeling using least‐squares optimization and more robustly estimates perfusion parameters when using empiric data labeled by an expert as the gold standard. Our technique is minimally sensitive to issues affecting the accuracy of perfusion parameter estimation, including rise time, noise, region of interest size, and frame rate. This framework could be of key utility in modeling different perfusion systems in different tissues and organs.
A comparison of the shielding effectiveness of silicone oil vitreous substitutes when used with Palladium‐103 and Iodine‐125 eye plaques
Authors: Yang You M. , Chow Phillip E. , McCannel Tara A. , Lamb James M.
Published: December 2018

Purpose

Episcleral eye plaques provide excellent local control of ocular melanoma, but vision sparing remains a significant problem with 30% or more of patients experiencing significant visual acuity degradation. The use of silicone oil shielding with Iodine‐125 plaques has previously been reported to improve critical structure sparing. We hypothesized that the use of Palladium‐103 would improve the shielding effectiveness of silicone oil due to the strong energy dependence of the photoelectric effect. This Monte Carlo simulation study reports a comparison of the shielding effects of silicone oil when used in conjunction with Pd‐103 and with I‐125 plaques.

Materials and methods

GEANT4 was used to simulate eye plaque treatments to an eye with either water‐equivalent vitreous humor, or silicone oil in place of the vitreous humor. Two solid gold plaques, 15 and 23 mm, were simulated loaded with I‐125 and with Pd‐103 source seeds. Seed activity was normalized such that 85 Gy was delivered to the tumor apex in the water‐equivalent cases. Tumor apex dose, central axis dose, and inner sclera dose reductions with silicone oil were evaluated.

Results

Silicone oil resulted in an underdosing to the tumor apex of 6.1% and 7.5% in the 15 mm plaque for I‐125 and Pd‐103, respectively, and 3.4% and 4.3% in the 23 mm plaque for I‐125 and Pd‐103, respectively. When renormalized to 85 Gy to the tumor apex in all scenarios, silicone oil reduced the dose to the inner sclera 90° from the plaque by 19–32% for the 15 and 23 mm plaques using I‐125, and by 33–65% for the 15 and 23 mm plaques using Pd‐103.

Conclusions

The combination of silicone oil and Pd‐103 eye plaques offers the potential for greatly improved sparing to normal structures compared to Pd‐103 plaques alone or I‐125 plaques with or without silicone oil.
In Situ Reduction of Graphene Oxide in Waterborne Polyurethane Matrix and the Healing Behavior of Nanocomposites by Multiple Ways
Authors: Wan Ting , Chen Dajun
Published: December 2018

Smart polymers are advanced materials that continue to attract scientific community. In this work, self‐healing waterborne polyurethane/reduced graphene oxide (SHWPU/rGO) nanocomposites were prepared by in situ chemical reduction of graphene oxide in a waterborne polyurethane matrix. The chemical structure, morphology, thermal stability, mechanical property, and electrical conductivity of the SHWPU/rGO nanocomposites were characterized. The prepared SHWPU/rGO nanocomposites were further treated under heating, microwave radiating, and electrifying conditions to investigate their healing property. The results showed that chemical reduction of graphene oxide was achieved using hydrazine hydrate as a reducing agent and the rGO was well dispersed in the SHWPU matrix. The thermal stability and mechanical properties of SHWPU/rGO nanocomposites were significantly increased. The SHWPU/rGO nanocomposites can be healed via different methods including heating, microwave radiating, and electrifying. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 202–209
Algorithms and experiments on routing of unmanned aerial vehicles with mobile recharging stations
Authors: Yu Kevin , Budhiraja Ashish Kumar , Buebel Spencer , Tokekar Pratap
Published: December 2018

We study the problem of planning a tour for an energy‐limited Unmanned Aerial Vehicle (UAV) to visit a set of sites in the least amount of time. We envision scenarios where the UAV can be recharged at a site or along an edge either by landing on stationary recharging stations or on Unmanned Ground Vehicles (UGVs) acting as mobile recharging stations. This leads to a new variant of the Traveling Salesperson Problem (TSP) with mobile recharging stations. We present an algorithm that finds not only the order in which to visit the sites but also when and where to land on the charging stations to recharge. Our algorithm plans tours for the UGVs as well as determines the best locations to place stationary charging stations. We study three variants for charging: Multiple stationary charging stations, single mobile charging station, and multiple mobile charging stations. As the problems we study are nondeterministic polynomial time (NP)‐Hard, we present a practical solution using Generalized TSP that finds the optimal solution that minimizes the total time, subject to the discretization of battery levels. If the UGVs are slower than the UAVs, then the algorithm also finds the minimum number of UGVs required to support the UAV mission such that the UAV is not required to wait for the UGV. Our simulation results show that the running time is acceptable for reasonably sized instances in practice. We evaluate the performance of our algorithm through simulations and proof‐of‐concept field experiments with a fully autonomous system of one UAV and UGV.
Generating and working with Drosophila cell cultures: Current challenges and opportunities
Authors: Luhur Arthur , Klueg Kristin M. , Zelhof Andrew C.
Published: December 2018

The use of Drosophila cell cultures has positively impacted both fundamental and biomedical research. The most widely used cell lines: Schneider, Kc, the CNS and imaginal disc lines continue to be the choice for many applications. Drosophila cell lines provide a homogenous source of cells suitable for biochemical experimentations, transcriptomics, functional genomics, and biomedical applications. They are amenable to RNA interference and serve as a platform for high‐throughput screens to identify relevant candidate genes or drugs for any biological process. Currently, CRISPR‐based functional genomics are also being developed for Drosophila cell lines. Even though many uniquely derived cell lines exist, cell genetic techniques such the transgenic UAS‐GAL4‐based RasV12 oncogene expression, CRISPR‐Cas9 editing and recombination mediated cassette exchange are likely to drive the establishment of many more lines from specific tissues, cells, or genotypes. However, the pace of creating new lines is hindered by several factors inherent to working with Drosophila cell cultures: single cell cloning, optimal media formulations and culture conditions capable of supporting lines from novel tissue sources or genotypes. Moreover, even though many Drosophila cell lines are morphologically and transcriptionally distinct it may be necessary to implement a standard for Drosophila cell line authentication, ensuring the identity and purity of each cell line. Altogether, recent advances and a standardized authentication effort should improve the utility of Drosophila cell cultures as a relevant model for fundamental and biomedical research.

This article is categorized under:

Technologies > Analysis of Cell, Tissue, and Animal Phenotypes
Determinantal Calabi-Yau varieties in Grassmannians and the Givental I-functions
Authors: Honma Yoshinori , Manabe Masahide
Published: December 2018

Abstract

We examine a class of Calabi-Yau varieties of the determinantal type in Grassmannians and clarify what kind of examples can be constructed explicitly. We also demonstrate how to compute their genus-0 Gromov-Witten invariants from the analysis of the Givental I-functions. By constructing I-functions from the supersymmetric localization formula for the two dimensional gauged linear sigma models, we describe an algorithm to evaluate the genus-0 A-model correlation functions appropriately. We also check that our results for the Gromov-Witten invariants are consistent with previous results for known examples included in our construction.
Impact of excessive sedimentation caused by anthropogenic activities on benthic suspension feeders in the Sea of Marmara
Authors: Topçu Nur Eda , Turgay Emre , Yardımcı Remziye Eda , Topaloğlu Bülent , Yüksek Ahsen , Steinum Terje M. , Karataş Süheyla , Öztürk Bayram
Published: December 2018

A massive die-off of benthic suspension feeders (BSF) covered by large amounts of sediments was observed along Prince Islands coasts (north-eastern Sea of Marmara) in August 2015. Alcyonarians, pennatulaceans, bivalves and sponges were severely affected. Many BSF probably died from burial and clogging of their feeding and respiratory apparatus. Of the gorgonian colonies, 66 ± 34% (mean ± SD) were dead, while 15 ± 16% (mean ± SD) displayed recent necrosis on the colony surface. In addition, histopathological and microbial examinations of the affected gorgonians and gold corals (Savalia savaglia) suggest that stress caused by sedimentation made them vulnerable to exploitation by consistently isolated opportunistic microorganisms. We isolatedVibrio splendidusandVibrio neptuniusfrom diseased gold coral colonies, but the bacterial isolates obtained from gorgonians could only be identified to genusVibriolevel. The presumably artificially introduced fungusMucor circinelloideswas common on both gold coral and gorgonians. This mould and opportunistic bacteria may have colonized BSF by taking advantage of low oxygen levels leading to impaired coral immune responses and thereby exacerbated the BSF mortality. Construction and landfill operations at Yassıada seem to be the greatest contributor to the observed sedimentation, as shown by silicate concentrations in nearby waters. These observations imply that preventive measures are necessary when construction operations take place in the vicinity of sensitive marine habitats.
The Emerging Welfare Mix for Syrian Refugees in Turkey: The Interplay between Humanitarian Assistance Programmes and the Turkish Welfare System
Authors: YILMAZ VOLKAN
Published: December 2018

This paper explores the key features of the emerging welfare mix for Syrian refugees in Turkey and identifies the modes of interaction between humanitarian assistance programmes, domestic policy responses and the Turkish welfare system. The welfare mix for Syrian refugees is a joint product of humanitarian assistance programmes implemented by international and domestic non-governmental organisations (NGOs) and domestic social policy programmes. Three policy domains are considered: social assistance schemes, employment and health care services. The paper suggests that granting of temporary protection status to Syrian migrants in Turkey and the agreement between Turkey and the EU shaped the welfare mix by empowering the public sector mandate vis-à-vis the humanitarian actors. As a result, the role of the public sector increases at the expense of NGOs, especially in social assistance and health care, while NGOs are increasingly specialised in protection work (especially in mental health support), where the Turkish welfare system has been weak. Employment has been essentially disregarded, in both humanitarian and social policy programmes, which casts doubt on the prospect of successful economic integration. Finally, this paper argues that the convergence of the rights of immigrants and citizens may well occur in mature components of less comprehensive welfare systems.
KEYNES, PUBLIC DEBT, AND THE COMPLEX OF INTEREST RATES
Authors: Aspromourgos Tony
Published: December 2018

John Maynard Keynes consistently offered qualified endorsement of Abba Lerner’s “functional finance” doctrine—the qualifications particularly turning on Keynes’s attentiveness to policy management of the psychology of the debt market. This article examines Keynes’s understanding of the possible influence of public debt on interest rates, from 1930 forward. With the multiplier a mechanism whereby debt-financed public investment generates matching private saving (net of private investment) plus public saving, it becomes possible for Keynes to conclude that increasing public debt need not place upward pressure on the level of interest rates, so long as policy can successfully manage the psychology of the debt market. This particularly concerns long interest rates and hence the term structure of rates. His theory of the term structure enables Keynes’s conviction that policy can manage and shape long rates. The conclusion considers also whether Keynes’s caution concerning public debt and interest rates retains relevance today.
Little Geodetic Evidence for Localized Indian Subduction in the Pamir‐Hindu Kush of Central Asia
Authors: Perry M. , Kakar N. , Ischuk A. , Metzger S. , Bendick R. , Molnar P. , Mohadjer S.
Published: December 2018

Geodetically derived velocities from Central Asia show that Northern Afghanistan, the Tajik Pamir, and northwestern Pakistan all move northward with comparable large velocities toward Eurasia. Steep velocity gradients, hence high strain rates, occur only across the Main Pamir Fault zone and with lesser magnitude between the northernmost Hindu Kush and the south and southeast margins of the Tajik Depression. Localized shortening is not apparent on any active India‐Hindu Kush crustal boundary; hence, crustal convergence between India and Eurasia in Central Asia is absorbed primarily on the northern and western margins of the Pamir. This concentrated strain on the Pamir margins is consistent with one, geometrically complex, interface between subducting Asian lithosphere and the Pamir. That interface might curve westward such that the Hindu Kush seismic zone is a continuation of the Pamir seismic zone, or alternatively, Hindu Kush earthquakes might occur in convectively unstable mantle lithosphere mechanically detached from surface faults.
Deglacial to Holocene Ocean Temperatures in the Humboldt Current System as Indicated by Alkenone Paleothermometry
Authors: Salvatteci Renato , Schneider Ralph R. , Blanz Thomas , Mollier‐Vogel Elfi
Published: December 2018

The response of the Humboldt Current System to future global warming is uncertain. Here we reconstruct alkenone‐derived near‐surface temperatures from multiple cores along the Peruvian coast to infer the driving mechanisms of upwelling changes for the last 20 kyr. Our records show a deglacial warming consistent with Antarctic ice‐core temperatures and a Mid‐Holocene cooling, which, in combination with other paleoceanographic records, suggest a strengthening of upwelling conditions. This cooling, during the globally warm Mid‐Holocene, is consistent with an intensification of the Walker Circulation and the South Eastern Pacific Subtropical Anticyclone, indicative of La Niña‐like conditions in the Tropical Pacific. Surprisingly, oxygen contents in the subsurface increased and productivity was low during the Mid‐Holocene, which are at odds with La Niña‐like conditions. This suggests that the Humboldt Current System reacts in multiple ways to a warmer world and may even include a reversal in the present day subsurface deoxygenation.
High performance solution-processed organic yellow light-emitting devices and fluoride ion sensors based on a versatile phosphorescent Ir(iii) complex
Authors: Yang Xiaolong , Feng Zhao , Dang Jingshuang , Sun Yuanhui , Zhou Guijiang , Wong Wai-Yeung
Published: December 2018

A versatile emitter is developed for solution-processed yellow OLEDs with an EQE of 18.7% and fluoride ion sensors with “color-switch” character.
Sulphide capacity of CaO-SiO2-8%MgO-Al2O3-BaO slags ranging from 0% to 5% in BaO
Authors: Ju Jiantao , Liu Wenguo , Xing Xiangdong , Wang Jing , An Jialiang
Published: December 2018

The sulphide capacities of CaO-SiO2-MgO-Al2O3-BaO slags were measured at 1773 K and 1823 K using the gas-slag equilibration method to estimate the desulphurization ability of the blast furnace slags that contained barium. The effects of basicity, the Al2O3 and BaO content of slags on the sulphide capacity of slags were studied. The relationship between the sulphide capacity and the optical basicity of the slags was also investigated. The experimentally determined results were compared with the sulphide capacities estimated by some previously reported models. The results showed that the sulphide capacity increased significantly when the basicity (CaO/SiO2) increased from 1.0 to 1.2, but decreased when the Al2O3 content increased in the slag. The increasing BaO content increased the sulphide capacity. The desulphurizing ability decreased when the BaO content was more than 3.5%. There was a linearly increasing relationship between the optical basicity and the sulphide capacity. The experimentally determined sulphide capacities were closest to the predicted values obtained by the Sosinsky and Sommerville’s model.
Preliminary studies on the batch-dissolution kinetics of calcite with reactors open and closed to CO2
Authors: Truesdale Victor W. , Greenwood Jim
Published: December 2018

Environmental contextThe dissolution of minerals in fresh or sea-waters is a critical environmental process. The rate at which substances dissolve, from the dissolution of calcite crystals to the weathering of mountains, can influence major global issues such as climate change and sea-level rise. This paper explores a new solution-based rate equation for mineral dissolution that has profound environmental consequences.
AbstractThis paper continues the search for a reliable, solution-based, rate equation for mineral dissolution, as the one dominant for over 40 years has recently been challenged by the Shrinking Object (SO) model. This study is needed to remedy several major environmental problems of immense social and economic importance including climate change, ocean acidification and industrial waste disposal. This paper describes the preliminary investigation of how reactors open and closed to CO2, which are used to study calcite dissolution, ought to be used with the SO model to gain maximum advantage. The open reactor is re-conceptualised as a constant head device for dissolved inorganic carbon, to give the kineticist a mechanistic description of it, to flesh out the thermodynamic categorisation. Application of this reveals that the recent experiments conducted in a reactor blown with CO2-free N2, which were central to the establishment of the concept of non-ideal dissolution of calcite, would have exaggerated the effect. Although this current study was still unable to determine conditions where the effect was absent, it does seem that it will be possible to skirt around this in the future, by approximating the classic works on the variation with pH of the initial rate of dissolution to full reaction curves from the SO model, which are exponential. To guide workers towards a further round of laboratory investigation on this, practical work on the dissolution of calcite crystallites in 0.311M Tris buffer at pH 8 or 9, under various partial pressures of CO2, in different reactors, and under various stirring and filtration strategies, is presented. Improved data runs, with unparalleled, strategically-spaced samplings, which show up the finer details of dissolution, can now be anticipated.
Ancestral sequence reconstruction: accounting for structural information by averaging over replacement matrices
Authors: Moshe Asher , Pupko Tal
Published: December 2018

Motivation

Ancestral sequence reconstruction (ASR) is widely used to understand protein evolution, structure and function. Current ASR methodologies do not fully consider differences in evolutionary constraints among positions imposed by the three-dimensional (3D) structure of the protein. Here, we developed an ASR algorithm that allows different protein sites to evolve according to different mixtures of replacement matrices. We show that assigning replacement matrices to protein positions based on their solvent accessibility leads to ASR with higher log-likelihoods compared to naïve models that assume a single replacement matrix for all sites. Improved ASR log-likelihoods are also demonstrated when solvent accessibility is predicted from protein sequences rather than inferred from a known 3D structure. Finally, we show that using such structure-aware mixture models results in substantial differences in the inferred ancestral sequences.

Availability and implementation

http://fastml.tau.ac.il.

Supplementary information

Supplementary data are available at Bioinformatics online.
Coprescribing of Benzodiazepines and Opioids in Older Adults: Rates, Correlates, and National Trends
Authors: Rhee Taeho Greg
Published: December 2018

Background

To estimate prescribing trends of and correlates independently associated with coprescribing of benzodiazepines and opioids among adults aged 65 years or older in office-based outpatient visits.

Methods

I examined a nationally representative sample of office-based physician visits by older adults between 2006 and 2015 (n = 109,149 unweighted) using data from the National Ambulatory Medical Care Surveys (NAMCS). National rates and prescribing trends were estimated. Then, I used multivariable logistic regression analyses to identify demographic and clinical factors associated with coprescriptions of benzodiazepines and opioids.

Results

From 2006 to 2015, 15,954 (14.6%) out of 109,149 visits, representative of 39.3 million visits nationally, listed benzodiazepine, opioid, or both medications prescribed. The rate of prescription benzodiazepines only increased monotonically from 4.8% in 2006–2007 to 6.2% in 2014–2015 (p < .001), and the rate of prescription opioids only increased monotonically from 5.9% in 2006–2007 to 10.0% in 2014–2015 (p < .001). The coprescribing rate of benzodiazepines and opioids increased over time from 1.1% in 2006–2007 to 2.7% in 2014–2015 (p < .001). Correlates independently associated with a higher likelihood of both benzodiazepine and opioid prescriptions included: female sex, a visit for chronic care, receipt of six or more concomitantly prescribed medications, and clinical diagnoses of anxiety and pain (p < .01 for all).

Conclusion

The coprescribing rate of benzodiazepines and opioids increased monotonically over time in outpatient care settings. Because couse of benzodiazepines and opioids is associated with medication burdens and potential harms, future research is needed to address medication safety in these vulnerable populations.
Perceived Effectiveness of Home-Based Primary Care Teams in Veterans Health Administration
Authors: Temkin-Greener Helena , Szydlowski Jill , Intrator Orna , Olsan Tobie , Karuza Jurgis , Cai Xueya , Gao Shan , Gillespie Suzanne M
Published: December 2018

Background and Objectives

Previous studies have shown that staff perception of team effectiveness is related to better health outcomes in various care settings. This study focused on the Veterans Health Administration’s Home-Based Primary Care (HBPC) program. We examined variations in HBPC interdisciplinary teamwork (IDT) and identified modifiable team and program characteristics that may influence staff perceptions of team effectiveness.

Research Design

We used a broadly validated survey instrument to measure perceived team effectiveness, workplace conditions/resources, group culture, and respondents’ characteristics. Surveys were initiated in January and completed in July, 2016.

Methods

Team membership rosters (n = 249) included 2,852 IDT members. The final analytical data set included 1,403 surveys (49%) from 221 (89%) teams. A generalized estimating equation model with logit link function, weighted by survey response rates, was used to examine factors associated with perceived team effectiveness.

Results

Respondents who served as primary care providers (PCPs) were 8% more likely (p = .0044) to view team’s performance as highly effective compared to other team members. Teams with nurse practitioners serving as team leader reported 6% higher likelihood of high-perceived team effectiveness (p = .0234). High team effectiveness was 13% more likely in sites where the predominant culture was characterized as group/developmental, and 7%–8% more likely in sites with lower environmental stress and better resources and staffing, respectively.

Conclusions and Implications

Team effectiveness is an important indirect measure of HBPC teams’ function. HBPC teams should examine their predominant culture, workplace stress, resources and staffing, and PCP leadership model as part of their quality improvement efforts.
Time Use and Experienced Wellbeing of Older Caregivers: A Sequence Analysis
Authors: Freedman Vicki A , Cornman Jennifer C , Carr Deborah , Lucas Richard E
Published: December 2018

Background and Objectives

The diminished wellbeing of caregivers is well documented, but studies typically draw upon coarse measures of time use and thus provide limited understanding of the role of specific care activities in the daily lives of care providers. This study uses time diary data to explore whether there are signature care patterns throughout the day and whether these care patterns have implications for caregivers’ experienced wellbeing.

Research Design and Methods

Using a national sample of 511 time diaries from older caregivers in the Disability and Use of Time supplement to the Panel Study of Income Dynamics, we examine minutes of care provided on the prior day, overall and for four broad care categories (household, personal care, transportation, and visiting), and patterns of care over the day, the latter based on sequence and cluster analysis.

Results

Older caregivers spend on average 2.3 hr providing care to another adult on care days. Caregiving follows a roller-coaster pattern over the day, peaking at mealtimes. Sequence analysis suggests five distinctive caregiving patterns, which vary by both demographic characteristics of the caregiver (gender, work status) and care arrangement type (relationship to recipient, whether sole caregiver to recipient). The 40% who provide only marginal assistance of about 1 hr report lower experienced wellbeing than the 28% who provide sporadic assistance with a mix of activities for about 2 hr.

Discussion and Implications

A substantial share of older caregivers provides only 1 hr of assistance on a given day but appears to be at risk for reduced wellbeing. Better understanding of the reason for their marginal involvement and reduced wellbeing is warranted.
Ocean currents predict fine-scale genetic structure and source-sink dynamics in a marine invertebrate coastal fishery
Authors: Silva C N S , Macdonald H S , Hadfield M G , Cryer M , Gardner J P A
Published: December 2018

Estimates of connectivity are vital for understanding population dynamics and for the design of spatial management areas. However, this is still a major challenge in the marine environment because the relative contributions of factors influencing connectivity amongst subpopulations are difficult to assess. This study combined population genetics with hydrodynamic modelling (Regional Ocean Modeling System, ROMS) to assess spatial and temporal exchange of individuals among subpopulations of the New Zealand scallop, Pecten novaezelandiae, within the Coromandel fishery area open to commercial fishing. Significant genetic differentiation was revealed among subpopulations with variable levels of recruitment. Connectivity, as assessed by ROMS, was a significant explanatory variable of genetic differentiation when accounting for the spatial dependency between locations. Although additional research is needed before source-sink population dynamics can be confidently used in management, these results imply that higher yields could be available from this fishery at lower risk of over-exploitation if the fishing of each subpopulation could be tailored to its contribution to recruitment, perhaps using subpopulation catch limits. This study highlights inter-annual patterns of connectivity, the importance of combining different methods for a better prediction of population dynamics, and how such an approach may contribute to management of living marine resources.
License to Assemble: Theorizing Brand Longevity
Authors: Preece Chloe , Kerrigan Finola , O’reilly Daragh
Published: December 2018

This study delineates the process of brand longevity: the achievement of social salience and ongoing consumer engagement over a sustained period. Our study contributes to branding theory by proposing a multilevel approach to understanding brand longevity through application of an assemblage perspective to answer the question: how do serial brands attain longevity within evolving sociocultural contexts? By applying assemblage theory, we scrutinize the enduring success of a serial media brand over the past 55 years. To address this question, a wide range of archival brand-related data were collected and analyzed, including: analysis of films, books, marketing materials, press commentaries, and reviews, as well as broader contextual data regarding the sociocultural contexts within which the brand assemblage has developed. Our findings empirically support the study of brand longevity in and of itself, and conceptualize brand longevity as relying on an evolutionary approach to assembling the brand, which looks outward from the brand in order to consider the potential of brand elements to prevail in contemporary contexts and to ensure both continuity and change.
The Respiratory Specimen Collection Trial (ReSpeCT): A Randomized Controlled Trial to Compare Quality and Timeliness of Respiratory Sample Collection in the Home by Parents and Healthcare Workers From Children Aged <2 Years
Authors: Zoch-Lesniak Beate , Ware Robert S , Grimwood Keith , Lambert Stephen B
Published: December 2018

Background

Most acute respiratory infection (ARI) research focuses on severe disease and overlooks the burden of community-managed illness. For community-based studies, home-based specimen collection by parents could be a resource-saving alternative to collection by healthcare workers (HCWs). In this study, we compared parent and HCW groups for their likelihood to collect specimens and the timeliness and quality of such collection.

Methods

In this unblinded randomized controlled trial, parents from Brisbane, Australia, were taught to identify new ARI episodes in their children aged <2 years. When their child had a new ARI, parents either collected a nasal swab from the child (P group) or contacted an HCW who visited to obtain a nasopharyngeal swab (HCW group). We compared the likelihood and timeliness of specimen collection and respiratory pathogen detection. A nested diagnostic study compared paired specimen collections from children in the HCW group.

Results

Included were 76 incident ARI episodes from 31 children and 102 episodes from 33 children in the P and HCW groups, respectively. The proportions of ARIs for which a specimen was collected were similar (P group, 69.7%; HCW group, 72.5%; P = .77), and pathogens were detected in 93.8% and 77.5% of the specimens, respectively (P = .03). The period between ARI onset and specimen collection was shorter in the P group than in the HCW group (mean difference, 1.9 days [95% confidence interval, 0.7–3.0 days]; P < .001). For the 69 paired specimens, viral loads were lower in the parent-collected swabs (mean cycle threshold difference, 4.5 [95% confidence interval, 3.1–5.9]; P < .001).

Conclusions

Parents and HCWs obtained samples in similar proportions of ARI episodes, but the parents collected the samples fewer days after ARI onset and with a resulting higher likelihood of pathogen identification. This method can be used in population-based epidemiological studies of ARI as a resource-saving alternative.

Trial Registration

ClinicalTrials.gov identifier NCT00966069.
Unique clinical features of cryptococcal meningitis among Chinese patients without predisposing diseases against patients with predisposing diseases
Authors: Xu Lijun , Zhang Xinyue , Guo Yongzheng , Tao Ran , Dai Xiahong , Yang Zongxing , Huang Ying , Zhu Biao , Xu Yan
Published: December 2018

The clinical features of cryptococcal meningitis (CM) in patients without predisposing diseases (PD) remain unclear. In sum, 162 of the 167 patients without PD and 162 of the 309 patients with PD were enrolled after propensity score matching. Demographic characteristics, symptoms, blood, and cerebrospinal fluid (CSF) characteristics were compared between the two groups. Kaplan-Meier curves and a Cox proportional hazards model were used to assess the factors associated with 10-week mortality. In total, approximately 35.1% of CM patients were without PD. CM patients without PD had blood profiles of higher white blood cells (WBC) [8.9(6.7–11.0) × 109/l], hemoglobin (128.4 ± 20.9 g/l), platelets [(226.2 ± 64.1) × 109/l], and serum albumin (41.2 ± 5.8 g/l) (all P ≤ .001) and CSF profiles of lower glucose (2.0 ± 1.2 mmol/l), pleocytosis [65.0 (18.0–160.0) × 106/l] and higher total protein [0.9 (0.7–1.4)g/l] (all P < .05). CM patients without PD had lower Cryptococcus culture positivity in CSF (62.5% vs. 74.1%, P = .039) but higher 2-week of CSF culture sterilization rates (69.4% vs. 51.3%, P = .031). The overall 10-week survival rate was 84.7% in patients without PD and 81.1% in patients with PD (Log-rank P = .439). CSF glucose <1.5 mmol/l, CSF fungal burden >20 cells/high power field and treatment lacking amphotericin B had a 3–4 times higher risk of death in patients without PD, whereas serum albumin <35 g/l, CSF glucose < 1.5 mmol/l, and CSF WBC <55 × 106 cell/l were risk factors for patients with PD. CM patients without PD had unique blood and CSF profiles, especially, had lower Cryptococcus culture positivity in CSF, and higher 2-week CSF culture sterilization. Low CSF glucose levels, higher fungal burden, and treatment without amphotericin B were risk factors for 10-week mortality.
Durability of Antibody Response Against the Hepatitis B Virus in Kidney Transplant Recipients: A Proposed Immunization Guideline From a 3-Year Follow-up Clinical Study
Authors: Chancharoenthana Wiwat , Leelahavanichkul Asada , Udomkarnjananun Suwasin , Wattanatorn Salin , Avihingsanon Yingyos , Praditpornsilpa Kearkiat , Tungsanga Kriang , Eiam-Ong Somchai , Townamchai Natavudh
Published: December 2018

Background

Despite the importance of hepatitis B virus (HBV) immunization in kidney transplantation (KT), data are lacking on fluctuations in hepatitis B surface antibody (anti-HBsAb) levels and optimal levels for KT recipients.

Methods

The study consisted of anti-HBsAb-positive recipients aged 18–70 years at the time of the KT. Recipients with anti-HBsAb <100 IU/L received a single booster HBV vaccination, and anti-HBsAb was measured at baseline and 3, 6, 12, 18, and 24 months post-KT. Anti-HBsAb, quantitative HBV deoxyribonucleic acid testing (12 and 24 months post-KT), and hepatitis B core-related antigen (24 months post-KT) were evaluated in recipients with anti-HBsAb >100 IU/L who received a hepatitis B surface antigen positive renal allograft.

Results

Seventy-six of 257 (29.6%) KT recipients with anti-HBsAb <100 IU/L at the time of enrollment received a single booster of HBV vaccination. Anti-HBsAb levels increased (≥100 IU/L) 1 and 3 months post-booster dose in 86% and 93% of cases, respectively. Anti-HBsAb levels were ≥100 IU/L in 95% of these recipients 6 months post-booster dose. Among 181 (70%) recipients with anti-HBsAb ≥100 IU/L without a booster dose, anti-HBsAb gradually decreased after the KT from 588 IU/L at baseline to 440 and 382 IU/L 3 and 6 months post-KT, respectively (P < .01).

Conclusions

To ensure optimal immunity against HBV, KT recipients should first be stratified according to their risk of HBV reactivation. Kidney transplantation recipients of renal allografts from HBV nonviremic or viremic donors should be reimmunized when their anti-HBsAb titers are <250 IU/L. A cutoff level of 100 IU/L is recommended in other cases.
Isolated Cerebral Alveolar Echinococcosis
Authors: Baldolli Aurélie , Bonhomme Julie , Yera Hélène , Grenouillet Frederic , Chapon Françoise , Barbier Charlotte , Hazera Pascal , Verdon Renaud
Published: December 2018

Cerebral alveolar echinococcosis (AE) is rare and mostly associated with liver involvement. We report an exceptional case of a 62-year-old man with a hereditary hemorrhagic telangiectasia harboring a primary cerebral AE mimicking neurocysticercosis with >100 cerebral lesions and without liver involvement.
The Role of Trimethoprim/Sulfamethoxazole in the Treatment of Infections Caused by Carbapenem-Resistant Enterobacteriaceae
Authors: Luterbach Courtney L , Boshe Ashley , Henderson Heather I , Cober Eric , Richter Sandra S , Salata Robert A , Kalayjian Robert C , Watkins Richard R , Hujer Andrea M , Hujer Kristine M , Rudin Susan D , Domitrovic T Nicholas , Doi Yohei , Kaye Keith S , Evans Scott , Fowler Vance G , Bonomo Robert A , van Duin David
Published: December 2018

In the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE), trimethoprim-sulfamethoxazole (TMP-SMX) had a limited role in the treatment of less severe carbapenem-resistant Enterobacteriaceae (CRE) infections, especially urinary tract infections. Of tested CRE, only 29% were susceptible to TMP-SMX. Development of resistance further limits the use of TMP-SMX in CRE infections.
Optimizing Long-Term Outcomes and Avoiding Failure With the Fibula Intramedullary Nail
Authors: Carter Thomas H. , Mackenzie Samuel P. , Bell Katrina R. , Bugler Kate E. , MacDonald Deborah , Duckworth Andrew D. , White Timothy O.
Published: December 2018

Objectives:

To identify risk factors for fixation failure, report patient outcomes, and advise on modifications to the surgical technique for fibula nail stabilization of unstable ankle fractures.

Design:

Retrospective review.

Setting:

Academic orthopaedic trauma unit.

Patients:

All 342 patients were identified retrospectively from a prospectively collected single-center trauma database over a 9-year period.

Intervention:

Unstable ankle fractures managed surgically with a fibula nail.

Main Outcome Measurements:

The primary short-term outcome was failure, defined as any case that required revision surgery because of an inadequate mechanical construct. The mid-term outcomes included the Olerud–Molander Ankle Score and the Manchester–Oxford Foot Questionnaire.

Results:

Twenty failures occurred (6%), of which 7 (2%) were due to device failure and 13 (4%) due to surgeon error. Of the surgeon errors, 8 consisted of inappropriate weight-bearing after syndesmotic diastasis, and 5 were due to inadequate fracture reduction or poor nail placement. Proximal locking screw (PLS) pull-out was the cause of all device failures. Positioning the PLS >20 mm above the plafond significantly increased failure risk (P = 0.003). At a mean follow-up of 5.1 years (range, 8 months–8 years) the median Olerud–Molander Ankle Score and Manchester–Oxford Foot Questionnaire were 80 (interquartile range, 45) and 10.94 (interquartile range, 44.00), respectively. Patient outcome was not negatively affected by the requirement for revision surgery.

Conclusions:

The fibula nail offers secure fixation and good patient-reported outcomes for unstable ankle fractures. Appropriate postoperative management and surgical technique, including careful placement of the PLS, is essential to minimize construct failure risk.

Level of Evidence:

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Ultrasound Evaluation of Quadriceps Muscle Dysfunction in Respiratory Disease
Authors: Parry Selina M. , Burtin Chris , Denehy Linda , Puthucheary Zudin A. , Bear Danielle
Published: December 2018

Purpose:

Peripheral muscle dysfunction can encompass reductions in muscle mass, strength, endurance, and fatigability, and is common in both critical illness and chronic respiratory diseases. There is growing interest in nonvolitional methods to quantify the severity of peripheral muscle dysfunction—in particular, the utility of ultrasonography. This review provides an up-to-date narrative synthesis of current knowledge around ultrasonography methodology and the quantitative and qualitative measures that can be obtained from ultrasound imaging. The application of ultrasonography in chronic respiratory disease and critical illness will be discussed alongside the need for standardized methodologies.

Quadriceps muscle dysfunction is multifactorial with changes in muscle quantity and quality impacting on patient clinical outcomes. There is significant variability in ultrasonography image acquisition and analysis methodologies, which requires standardization. Ultrasound imaging is a promising evaluation tool that may enable identification of individuals at highest risk of muscle dysfunction and thus targeting of intervention resources.

Conclusion:

Ultrasonography is noninvasive and easily integrated at the bedside in clinical practice. A range of quantitative and qualitative parameters can be assessed to provide detail on severity of peripheral muscle dysfunction in respiratory disease. There is significant variability in the application of ultrasonography, in order for the field to progress standardized approach to ultrasonography needs to be developed.
Spontaneous bacterial peritonitis recurrence in patients with cirrhosis receiving secondary prophylaxis with norfloxacin
Authors: Marciano Sebastián , Dirchwolf Melisa , Diaz Juan M. , Bermudez Carla , Gutierrez-Acevedo Maria N. , Barcán Laura A. , Smud Astrid , Giunta Diego , Gadano Adrián C.
Published: December 2018

Objective

Few studies carried out more than 20 years ago have evaluated spontaneous bacterial peritonitis (SBP) recurrence in patients receiving secondary antibiotic prophylaxis. These studies reported a 1-year recurrence rate of 20–26%. Changes in the bacteriology of SBP over the last few years might have negative effects on secondary prophylaxis. Our primary aim was to estimate the incidence of SBP recurrence in patients with cirrhosis receiving secondary prophylaxis with norfloxacin and to explore the factors associated with SBP recurrence.

Patients and methods

This was a retrospective cohort study of patients receiving norfloxacin for the secondary prophylaxis of SBP from 1 March 2003 to 31 March 2016. Follow-up was performed for 365 days after secondary prophylaxis was started. A competing risk analysis approach was used.

Results

A total of 115 patients were included. The prevalence of quinolone-resistant and multiresistant bacteria in the first episode of SBP among patients with culture-positive SBP was 70.96% [95% confidence interval (CI): 51.96–85.77%] and 12.90% (95% CI: 3.63–29.83%), respectively. The cumulative incidence of SBP recurrence was 28.53% (95% CI: 20.15–37.45%) after 365 days. Male patients showed an estimated subhazard ratio of SBP recurrence of 2.52 (95% CI: 1.07–5.91, P=0.034). No other risk factors for SBP recurrence were identified. The overall cumulative incidence of death after 365 days was 21.57% (95% CI: 14.14–30.04%), without significant differences among patients with or without SBP recurrence.

Conclusion

Even though changes in the bacteriology of SBP occurred over time, its recurrence rate in patients receiving norfloxacin remains similar to what was reported in the initial studies.
A Comparison of Acellular Dermal Matrices in Abdominal Wall Reconstruction
Authors: Maxwell Daniel W. , Hart Alexandra M. , Keifer Orion P. , Halani Sameer H. , Losken Albert
Published: December 2018

Background

There is a growing literature of evidence that the use of acellular dermal matrices (ADMs) in abdominal wall reconstruction (AWR) for high-risk patients provides superior complication profiles when compared with standard synthetic mesh. Here we compare Fortiva, Strattice, and Alloderm ADMs in AWR.

Methods

In a prospectively maintained database, all patients undergoing AWR between January 2003 and November 2016 were reviewed. Hernia recurrence and surgical site occurrence (SSO) were our primary and secondary endpoints. Kaplan-Meier survival curves and logistic regression models were used to evaluate risks for hernia recurrence and SSO.

Results

A total of 229 patients underwent AWR with 1 of 3 ADMs. Median follow-up time was 20.9 months (1–60 months). Cumulative recurrence rates for each mesh were 6.9%, 11.2%, and 22.0% (P = 0.04), for Fortiva, Strattice, and Alloderm groups. Surgical site occurrence for each mesh was 56.9%, 49.0%, and 49.2%, respectively. Seroma was significantly lower in the Fortiva group (1.4%; P = 0.02). Independent risk factors hernia recurrence included body mass index of 30 kg/m2 or higher and hypertension. Adjusted risk factors included oncologic resection for hernia recurrence (odds ratio, 5.3; confidence interval, 1.1–97.7; P = 0.11) and a wound class of contaminated or dirty/infected for SSO (odds ratio, 3.6; confidence interval, 1.0–16.6; P = 0.07).

Conclusions

Acellular dermal matrices provide a durable repair with low overall rate of recurrence and complications in AWR. The recurrence and complication profiles differ between brands. With proper patient selection and consideration, ADMs can be used confidently for a variety of indications and wound classifications.