bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphate Removal by Peritoneal Dialysis: The Effect of Transporter Status and Peritoneal Dialysis Prescription
Authors: Courivaud Cecile , Davenport Andrew
Published: July 2015

♦ Background

Interventional trials failed to demonstrate that increasing urea clearance improved peritoneal dialysis (PD) patient survival. Hyperphosphatemia is a well- recognized predictor of cardiovascular and all-cause mortality in PD patients. Simplification of PD small solute clearance targets focuses away from larger solutes, including phosphate. In the US and UK, increasing use of automated peritoneal dialysis (APD) cyclers with shorter dwell times could also potentially reduce peritoneal phosphate removal compared to continuous ambulatory peritoneal dialysis (CAPD).

♦ Methods

Total phosphate and peritoneal phosphate clearances were measured in a prospective observational cohort of 380 adult PD patients attending a tertiary university hospital between 1996 and 2013 for routine assessment of PD adequacy.

♦Results

Eighty-seven patients (22.9%) were hyperphosphatemic. Taking the mean 4-hour dialysate to plasma (D/P) ratio for phosphate, 193 (50.8%) were fast and fast-average transporters and 187 (49.2%) were slow and slow-average transporters (compared to 276 [72.6%] and 104 [27.4%], respectively, for peritoneal creatinine transporter status). Faster peritoneal phosphate transporter status was associated with over-hydration (odds ratio [OR] = 2.45 [1.43 – 4.20], p = 0.001). Whereas the 4-hour D/P creatinine and peritoneal weekly creatinine clearance did not differ between those who were hyperphosphatemic or not, the hyperphosphatemic patients had lower 4-hour D/P phosphate and lower peritoneal weekly phosphate clearance ( p = 0.019, and p = 0.06 respectively). We found greater peritoneal phosphate clearance for patients choosing CAPD compared to APD, irrespective of the peritoneal phosphate transporter status.

♦ Conclusion

Peritoneal creatinine transporter status and creatinine clearance cannot be used as surrogate markers of peritoneal phosphate transport and clearance. Hyperphosphatemia was more common in PD patients with slower peritoneal transporter status and lower peritoneal phosphate clearance. Greater peritoneal phosphate clearance was achieved with CAPD prescriptions. Slower peritoneal transporters should be advised to choose CAPD to improve serum phosphate control.
The Effect of Exit-Site Antibacterial Honey versus Nasal Mupirocin Prophylaxis on the Microbiology and Outcomes of Peritoneal Dialysis-Associated Peritonitis and Exit-Site Infections: A Sub-Study of the Honeypot Trial
Authors: Zhang Lei , Badve Sunil V. , Pascoe Elaine M. , Beller Elaine , Cass Alan , Clark Carolyn , de Zoysa Janak , Isbel Nicole M. , McTaggart Steven , Morrish Alicia T. , Playford E. Geoffrey , Scaria Anish , Snelling Paul , Vergara Liza A. , Hawley Carmel M. , Johnson David W.
Published: July 2015

Background

The HONEYPOT study recently reported that daily exit-site application of antibacterial honey was not superior to nasal mupirocin prophylaxis for preventing overall peritoneal dialysis (PD)-related infection. This paper reports a secondary outcome analysis of the HONEYPOT study with respect to exit-site infection (ESI) and peritonitis microbiology, infectious hospitalization and technique failure.

Methods

A total of 371 PD patients were randomized to daily exit-site application of antibacterial honey plus usual exit-site care ( N = 186) or intranasal mupirocin prophylaxis (in nasal Staphylococcus aureus carriers only) plus usual exit-site care (control, N = 185). Groups were compared on rates of organism-specific ESI and peritonitis, peritonitis-and infection-associated hospitalization, and technique failure (PD withdrawal).

Results

The mean peritonitis rates in the honey and control groups were 0.41 (95% confidence interval [CI] 0.32 – 0.50) and 0.41 (95% CI 0.33 – 0.49) episodes per patient-year, respectively (incidence rate ratio [IRR] 1.01, 95% CI 0.75 – 1.35). When specific causative organisms were examined, no differences were observed between the groups for gram-positive (IRR 0.99, 95% CI 0.66 – 1.49), gram-negative (IRR 0.71, 95% CI 0.39 – 1.29), culture-negative (IRR 2.01, 95% CI 0.91 – 4.42), or polymicrobial peritonitis (IRR 1.08, 95% CI 0.36 – 3.20). Exit-site infection rates were 0.37 (95% CI 0.28 – 0.45) and 0.33 (95% CI 0.26 – 0.40) episodes per patient-year for the honey and control groups, respectively (IRR 1.12, 95% CI 0.81 – 1.53). No significant differences were observed between the groups for gram-positive (IRR 1.10, 95% CI 0.70 – 1.72), gram-negative (IRR: 0.85, 95% CI 0.46 – 1.58), culture-negative (IRR 1.88, 95% CI 0.67 – 5.29), or polymicrobial ESI (IRR 1.00, 95% CI 0.40 – 2.54). Times to first peritonitis-associated and first infection-associated hospitalization were similar in the honey and control groups. The rates of technique failure (PD withdrawal) due to PD-related infection were not significantly different between the groups.

Conclusion

Compared with standard nasal mupirocin prophylaxis, daily topical exit-site application of antibacterial honey resulted in comparable rates of organism-specific peritonitis and ESI, infection-associated hospitalization, and infection-associated technique failure in PD patients.
ISPD Cardiovascular and Metabolic Guidelines in Adult Peritoneal Dialysis Patients Part II – Management of Various Cardiovascular Complications
Authors: Wang Angela Yee Moon , Brimble K. Scott , Brunier Gillian , Holt Stephen G. , Jha Vivekanand , Johnson David W. , Kang Shin-Wook , Kooman Jeroen P. , Lambie Mark , McIntyre Chris , Mehrotra Rajnish , Pecoits-Filho Roberto
Published: July 2015

Cardiovascular mortality has remained high in patients on peritoneal dialysis (PD) due to the high prevalence of various cardiovascular complications including coronary artery disease, left ventricular hypertrophy and dysfunction, heart failure, arrhythmia (especially atrial fibrillation), cerebrovascular disease, and peripheral arterial disease. In addition, nearly a quarter of PD patients develop sudden cardiac death as the terminal life event. Thus, it is essential to identify effective treatment that may lower cardiovascular mortality and improve survival of PD patients. The International Society for Peritoneal Dialysis (ISPD) commissioned a global workgroup in 2012 to formulate a series of recommendation statements regarding lifestyle modification, assessment and management of various cardiovascular risk factors, and management of the various cardiovascular complications to be published in 2 guideline documents. This publication forms the second part of the guideline documents and includes recommendation statements on the management of various cardiovascular complications in adult chronic PD patients. The documents are intended to serve as a global clinical practice guideline for clinicians who look after PD patients. We also define areas where evidence is clearly deficient and make suggestions for future research in each specific area.
Synthesis of γ-hydroxypropyl P-chirogenic (±)-phosphorus oxide derivatives by regioselective ring-opening of oxaphospholane 2-oxide precursors
Authors: Binyamin Iris , Meidan-Shani Shoval , Ashkenazi Nissan
Published: July 2015

The synthesis of P-chirogenic (±)-phosphine oxides and phosphinates via selective nucleophilic ring opening of the corresponding oxaphospholanes is described. Two representative substrates: the phosphonate 2-ethoxy-1,2-oxaphospholane 2-oxide and the phosphinate 2-phenyl-1,2-oxaphospholane 2-oxide were reacted with various Grignard reagents to produce a single alkyl/aryl product. These products may possess further functionalities in addition to the phosphorus center such as the γ-hydroxypropyl group which results from the ring opening and π-donor moieties such as aryl, allyl, propargyl and allene which originates from the Grignard reagent.
Prevalence and patterns of infection in critically ill trauma patients admitted to the trauma ICU, South Africa
Authors: Pillai Jayandiran , Yazicioglu Ceyhan , Moeng Steve , Rangaka Thomas , Monareng Taalib , Jayakrishnan Raja , Veller Martin , Pinkus Daniella
Published: July 2015

Introduction: The aim of this study was to determine if any patterns of infection or bacterial resistance existed in critically ill polytrauma patients admitted to the intensive care unit (ICU) at the CM Johannesburg Academic Hospital (CMJAH). Methods: This was a prospective, single-center study of patient laboratory records of 73 critically injured polytrauma patients admitted to an ICU. The data collected from each patient, beginning with admission and extending until discharge from the ICU, included age, gender, admission hemoglobin levels, injury severity score, length of ICU stay, microbiological cultures and sensitivity (MCS), and types and numbers of surgical procedures. Results: Upon admission to the ICU, the injury severity score (ISS) was 40.86 (± 15.64). In total, 73.98% of the patients required the use of a ventilator during their ICU stay. The most prevalent organisms isolated from specimens were Pseudomonas aeruginosa (30.1%), Klebsiella species (25.7%), Acinetobacterbaumanni (16.4%), and Staphylococcus aureus (5.8%). Multi-drug resistance (MDR) was identified in 63% of patients, with Klebsiella (73.91%) and Pseudomonas (65.21%) occurring most frequently. Multivariate analysis showed MDR to be the only significant predictor associated with a higher risk for hospital mortality when age, gender, ventilation, duration of ICU stay, ISS score, and the number of surgeries undergone was taken into account. Conclusion: Critically ill polytrauma patients are at particularly high risk for Gram-negative sepsis.
Retrospective screening of acute undifferentiated fever serum samples with universal flavivirus primers
Authors: Khongwichit Sarawut , Libsittikul Sirikwan , Yoksan Sutee , Auewarakul Prasert , Suputtamongkol Yupin , Smith Duncan R.
Published: July 2015

Introduction: Fever is a common symptom of many tropical diseases and in many cases the etiologic agent remains unidentified as a consequence of either the etiologic agent not being part of routine diagnostic screening or as a consequence of false negatives on standard diagnostic tests. Methodology: This study screened a well characterized panel of 274 serum samples collected on day of admission from adult patients with acute undifferentiated fever admitted to a hospital in Nakhon Ratchasima, Thailand by RT-PCR using pan-flavivirus degenerate primers. Results: Subsequent clinical diagnosis was achieved for 38 of the patients, and included 19 cases of dengue fever. RT-PCR screening identified seven positive samples (2.5%) which were revealed by sequence analysis to be dengue virus 1 (2 cases), dengue virus 2 (2 cases) and dengue virus 3 (3 cases). Only 5 out of 19 (26%) serum samples from patients subsequently diagnosed with dengue were positive, but 2 samples which clinically remained undiagnosed were shown to be positive for dengue virus. Sequence analysis suggested that the dengue virus 3 cases occurred as a result of importation of a strain of dengue from India or China. No other flaviviruses were identified. Conclusions: No evidence was found of other flaviviruses besides dengue circulating in this population. Despite improved diagnostic tests, cases of dengue are still evading correct diagnosis.
Molecular and phenotypic characteristics of methicillin-resistant Staphylococcus aureus isolated from hospitalized patients
Authors: Oliveira Caio Ferreira de , Morey Alexandre Tadachi , Santos Jussevania Pereira , Gomes Ludmila Vilela Pereira , Cardoso Juscélio Donizete , Pinge-Filho Phileno , Perugini Márcia Regina Eches , Yamauchi Lucy Megumi , Yamada-Ogattta Sueli Fumie
Published: July 2015

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of infections acquired in both community and hospital settings. In this study, MRSA isolated from different sources of hospitalized patients was characterized by molecular and phenotypic methods. Methodology: A total of 123 S. aureus isolates were characterized according to their genetic relatedness by repetitive element sequence based-PCR (REP-PCR), in vitro antimicrobial susceptibility profile, SCCmec typing and presence of seven virulence factor-encoding genes. Results: REP-PCR fingerprinting showed low relatedness between the isolates, and the predominance of one specific lineage or clonal group was not observed. All isolates were susceptible to teicoplanin and linezolide. All isolates were resistant to cefoxitin and penicillin, and the majority were also resistant to one or more other antimicrobials. Fifty isolates (41.7%) were intermediately resistant to vancomycin. Most isolates harbored SCCmec type II (53.7%), followed by type I (22.8%), type IV (8.1%) and type III (1.6%). All isolates harbored at least two virulence factor-encoding genes, and the prevalence was as follows: coa, 100%; icaA, 100%; hla, 13.0%; hlb, 91.1%, hld, 91.1%; lukS-PV and lukF-PV, 2.4%; and tst, 34.1%. A positive association with the presence of hla and SCCmec type II, and tst and SCCmec type I was observed. Conclusion: This study showed the high virulence potential of multidrug-resistant MRSA circulating in a teaching hospital. A high prevalence of MRSA showing intermediate vancomycin resistance was also observed, indicating the urgent need to improve strategies for controlling the use of antimicrobials for appropriate management of S. aureus infections.
The Mexican political fracture and the 1954 coup in Guatemala (The beginnings of the cold war in Latin America)
Authors: Loaeza Soledad
Published: July 2015

This article challenges two general assumptions that have guided the study of Mexican foreign policy in the last four decades. First, that from this policy emerges national consensus; and, secondly that between Mexico and the US there is a “special relation” thanks to which Mexico has been able to develop an autonomous foreign policy. The two assumptions are discussed in light of the impact on Mexican domestic politics of the 1954 USsponsored military coup against the government of government of Guatemala. In Mexico, the US intervention reopened a political fracture that had first appeared in the 1930’s, as a result of President Cárdenas’radical policies that divided Mexican society. These divisions were barely dissimulated by the nationalist doctrine adopted by the government. The Guatemalan Crisis brought some of them into the open. The Mexican President, Adolfo Ruiz Cortines’ priority was the preservation of political stability. He feared the US government might feel the need to intervene in Mexico to prevent a serious disruption of the status quo. Thus, Ruiz Cortines found himself in a delicate position in which he had to solve the conflicts derived from a divided elite and a fractured society, all this under the pressure of US’ expectations regarding a secure southern border.
Comparative systems and the functioning of networks: the Caribbean and Indo-Pacific models of trade. XVII and XVIII centuries
Authors: Picazo Muntaner Antoni
Published: July 2015

All commercial networks operating during the First Global Age in the Atlantic and Indo-Pacific systems had a number of common elements, although it is also true that in these two areas of study, very different dynamics emerged. In both areas, the strategies implemented by networks were designed to make them extremely cooperative, very dynamic, with a nonlinear structure and multifunctional. In contrast, noteworthy among the most significant differences is the high degree of participation of native traders and commercial networks in the Asia-Pacific, with Europeans taking part and learning alongside them, while the Atlantic, and the Caribbean in particular, were essentially European in nature.
IL-7/IL-7 Receptor Signaling Differentially Affects Effector CD4+ T Cell Subsets Involved in Experimental Autoimmune Encephalomyelitis
Authors: Arbelaez Carlos A. , Glatigny Simon , Duhen Rebekka , Eberl Gerard , Oukka Mohamed , Bettelli Estelle
Published: July 2015

IL-17–producing CD4+ T (Th17) cells, along with IFN-γ–expressing Th1 cells, represent two major pathogenic T cell subsets in experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). The cytokines and transcription factors involved in the development and effector functions of Th1 and Th17 cells have been largely characterized. Among them, IL-23 is essential for the generation of stable and encephalitogenic Th17 cells and for the development of EAE. The IL-7/IL-7R signaling axis participates in cell survival, and perturbation of this pathway has been associated with enhanced susceptibility to MS. A link between IL-23–driven pathogenic T cells and IL-7/IL-7R signaling has previously been proposed, but has not been formally addressed. In the current study, we showed that Th17 cells from mice with EAE express high levels of IL-7Rα compared with Th1 cells. Using mice that constitutively express IL-7Rα on T cells, we determined that sustained IL-7R expression in IL-23R–deficient mice could not drive pathogenic T cells and the development of EAE. IL-7 inhibited the differentiation of Th17 cells, but promoted IFN-γ and GM-CSF secretion in vitro. In vivo IL-7/anti–IL-7 mAb complexes selectively expanded and enhanced the proliferation of CXCR3-expressing Th1 cells, but did not impact Th17 cells and EAE development in wild-type and IL-23R–deficient mice. Importantly, high IL-7 expression was detected in the CNS during EAE and could drive the plasticity of Th17 cells to IFN-γ–producing T cells. Together, these data address the contribution of IL-23/IL-23R and IL-7/IL-7R signaling in Th17 and Th1 cell dynamics during CNS autoimmunity.
Vibrio vulnificus VvpE Stimulates IL-1β Production by the Hypomethylation of the IL-1β Promoter and NF-κB Activation via Lipid Raft–Dependent ANXA2 Recruitment and Reactive Oxygen Species Signaling in Intestinal Epithelial Cells
Authors: Lee Sei-Jung , Jung Young Hyun , Song Eun Ju , Jang Kyung Ku , Choi Sang Ho , Han Ho Jae
Published: July 2015

An inflammatory response is a hallmark of necrosis evoked by bacterial pathogens. Vibrio vulnificus, VvpE, is an elastase that is responsible for tissue necrosis and inflammation; however, the molecular mechanism by which it regulates host cell death has not been characterized. In the present study, we investigate the cellular mechanism of VvpE with regard to host cell death and the inflammatory response of human intestinal epithelial (INT-407) cells. The recombinant protein (r)VvpE (50 pg/ml) caused cytotoxicity mainly via necrosis coupled with IL-1β production. The necrotic cell death induced by rVvpE is highly susceptible to the knockdown of annexin A (ANXA)2 and the sequestration of membrane cholesterol. We found that rVvpE induces the recruitment of NADPH oxidase 2 and neutrophil cytosolic factor 1 into membrane lipid rafts coupled with ANXA2 to facilitate the production of reactive oxygen species (ROS). The bacterial signaling of rVvpE through ROS production is uniquely mediated by the phosphorylation of redox-sensitive transcription factor NF-κB. The silencing of NF-κB inhibited IL-1β production during necrosis. rVvpE induced hypomethylation and region-specific transcriptional occupancy by NF-κB in the IL-1β promoter and has the ability to induce pyroptosis via NOD-, LRR-, and pyrin domain–containing 3 inflammasome. In a mouse model of V. vulnificus infection, the mutation of the vvpE gene from V. vulnificus negated the proinflammatory responses and maintained the physiological levels of the proliferation and migration of enterocytes. These results demonstrate that VvpE induces the hypomethylation of the IL-1β promoter and the transcriptional regulation of NF-κB through lipid raft–dependent ANXA2 recruitment and ROS signaling to promote IL-1β production in intestinal epithelial cells.
Cutting Edge: cGAS Is Required for Lethal Autoimmune Disease in the Trex1-Deficient Mouse Model of Aicardi–Goutières Syndrome
Authors: Gray Elizabeth E. , Treuting Piper M. , Woodward Joshua J. , Stetson Daniel B.
Published: July 2015

Detection of intracellular DNA triggers activation of the stimulator of IFN genes–dependent IFN-stimulatory DNA (ISD) pathway, which is essential for antiviral immune responses. However, chronic activation of this pathway is implicated in autoimmunity. Mutations in TREX1, a 3′ repair exonuclease that degrades cytosolic DNA, cause Aicardi–Goutières syndrome and chilblain lupus. Trex1−/− mice develop lethal, IFN-driven autoimmune disease that is dependent on activation of the ISD pathway, but the DNA sensors that detect the endogenous DNA that accumulates in Trex1−/− mice have not been defined. Multiple DNA sensors have been proposed to activate the ISD pathway, including cyclic GMP–AMP synthase (cGAS). In this study, we show that Trex1−/− mice lacking cGAS are completely protected from lethality, exhibit dramatically reduced tissue inflammation, and fail to develop autoantibodies. These findings implicate cGAS as a key driver of autoimmune disease and suggest that cGAS inhibitors may be useful therapeutics for Aicardi–Goutières syndrome and related autoimmune diseases.
Space weather
Authors:   Canadian Space Weather Forecast Centre
Published: July 2015

Space weather refers to changes in the space environment and geomagnetic storms resulting from eruptions on the Sun. Space weather ultimately affects human activities and technologies on Earth and in space.
Novel Method to Improve Radiologist Agreement in Interpretation of Serial Chest Radiographs in the ICU
Authors: Castro Denise A , Naqvi Asad A , Manson David , Flavin Michael P , VanDenKerkhof Elizabeth , Soboleski Donald
Published: July 2015

Objectives:

To determine whether a novel method and device, called a variable attenuation plate (VAP), which equalizes chest radiographic appearance and allows for synchronization of manual image windowing with comparison studies, would improve consistency in interpretation.

Materials and Methods:

Research ethics board approved the prospective cohort pilot study, which included 50 patients in the intensive care unit (ICU) undergoing two serial chest radiographs with a VAP placed on each one of them. The VAP allowed for equalization of density and contrast between the patients’ serial chest radiographs. Three radiologists interpreted all the studies with and without the use of VAP. Kappa and percent agreement was used to calculate agreement between radiologists’ interpretations with and without the plate.

Results:

Radiologist agreement was substantially higher with the VAP method, as compared to that with the non-VAP method. Kappa values between Radiologists A and B, A and C, and B and C were 46%, 55%, and 51%, respectively, which improved to 73%, 81%, and 66%, respectively, with the use of VAP. Discrepant report impressions (i.e., one radiologist's impression of unchanged versus one or both of the other radiologists stating improved or worsened in their impression) ranged from 24 to 28.6% without the use of VAP and from 10 to 16% with the use of VAP (χ2= 7.454,P< 0.01). Opposing views (i.e., one radiologist's impression of improved and one of the others stating disease progression or vice versa) were reported in 7 (12%) cases in the non-VAP group and 4 (7%) cases in the VAP group (χ2= 0.85,P= 0.54).

Conclusion:

Numerous factors play a role in image acquisition and image quality, which can contribute to poor consistency and reliability of portable chest radiographic interpretations. Radiologists’ agreement of image interpretation can be improved by use of a novel method consisting of a VAP and associated software and has the potential to improve patient care.
Corticosteroid Responsive Sarcoidosis with Multisystemic Involvement Years after Initial Diagnosis: A Lymphoma Mimicker on 18-FDG PET/CT
Authors: Acar Turker , Savas Recep , Kocacelebi Kenan , Ucan Eyup Sabri
Published: July 2015

Sarcoidosis is a chronic multisystemic inflammatory disease characterized by noncaseating epithelioid cell granulomas. 18-Fluorodeoxyglucose positron-emission tomography/computer tomography (FDG-PET/CT) is increasingly used in routine clinical practice to assess active sarcoidosis because it can detect active inflammatory granulomatous disease. However, active sarcoidosis lesions are observed to be hypermetabolic on FDG-PET/CT much like malignancies, which may lead to misinterpretation on imaging. In this case report, we present a rare case of sarcoidosis with multisystem involvement including lung, lymph nodes, bone, pleura, and soft tissue that mimicked lymphoma on FDG-PET/CT and responded to corticosteroid treatment.
Secondary Data Analytics of Aquaporin Expression Levels in Glioblastoma Stem-Like Cells
Authors: Isokpehi Raphael D. , Valero Katharina C. Wollenberg , Graham Barbara E. , Pacurari Maricica , Sims Jennifer N. , Udensi Udensi K. , Ndebele Kenneth
Published: July 2015

Glioblastoma is the most common brain tumor in adults in which recurrence has been attributed to the presence of cancer stem cells in a hypoxic microenvironment. On the basis of tumor formation in vivo and growth type in vitro, two published microarray gene expression profiling studies grouped nine glioblastoma stem-like (GS) cell lines into one of two groups: full (GSf) or restricted (GSr) stem-like phenotypes. Aquaporin-1 (AQP1) and aquaporin-4 (AQP4) are water transport proteins that are highly expressed in primary glial-derived tumors. However, the expression levels of AQP1 and AQP4 have not been previously described in a panel of 92 glioma samples. Therefore, we designed secondary data analytics methods to determine the expression levels of AQP1 and AQP4 in GS cell lines and glioblastoma neurospheres. Our investigation also included a total of 2,566 expression levels from 28 Affymetrix microarray probe sets encoding 13 human aquaporins (AQP0–AQP12); CXCR4 (the receptor for stromal cell derived factor-1 [SDF-1], a potential glioma stem cell therapeutic target]); and PROM1 (gene encoding CD133, the widely used glioma stem cell marker). Interactive visual representation designs for integrating phenotypic features and expression levels revealed that inverse expression levels of AQP1 and AQP4 correlate with distinct phenotypes in a set of cell lines grouped into full and restricted stem-like phenotypes. Discriminant function analysis further revealed that AQP1 and AQP4 expression are better predictors for tumor formation and growth types in glioblastoma stem-like cells than are CXCR4 and PROM1. Future investigations are needed to characterize the molecular mechanisms for inverse expression levels of AQP1 and AQP4 in the glioblastoma stem-like neurospheres.
Efficacy of Single-stage Revision with Aggressive Debridement Using Intra-articular Antibiotics in the Treatment of Infected Joint Prosthesis
Authors: Antony Suresh J. , Westbrook Richard S. , Jackson John S. , Heydemann Jacob S. , Nelson Jenny L.
Published: July 2015

Prosthetic joint infections (PJI) of the hip and knee are uncommon, but result in significant morbidity and mortality when they do occur. Current management consists of a combination of either single- or two-stage exchange of the prosthesis and/or exchange of polymer components with intravenous (IV) antibiotics (4–6 weeks) and intraoperative debridement of the joint prior to reimplantation. However, failure rate, morbidity, and expense associated with current management are high, especially if the infection involves resistant pathogens and/or osteomyelitis. Also, the current use of systemic antibiotics does not allow for high local concentrations of the drug and biofilm penetration of the infected prosthesis. To overcome these difficulties, we examined the outcomes of aggressive operative debridement of the infected prosthesis. This was achieved through the use of a single-stage revision and administration of high concentrations of local intra-articular antibiotics via Hickman catheters. We present 57 patients with PJI who were treated with intra-articular antibiotics and single-stage revisions. Minimal systemic toxicity was observed along with a 100% microbiologic cure rate and 89% without relapse at 11-month follow-up despite isolation of multidrug resistant pathogens. This is the largest study to date using this method in the treatment of PJI.
Preconditioned Iterative Methods for Two-Dimensional Space-Fractional Diffusion Equations
Authors: Jin Xiao-Qing , Lin Fu-Rong , Zhao Zhi
Published: July 2015

In this paper, preconditioned iterative methods for solving two-dimensional space-fractional diffusion equations are considered. The fractional diffusion equation is discretized by a second-order finite difference scheme, namely, the Crank-Nicolson weighted and shifted Grünwald difference (CN-WSGD) scheme proposed in [W. Tian, H. Zhou and W. Deng, A class of second order difference approximation for solving space fractional diffusion equations, Math. Comp., 84 (2015) 1703-1727]. For the discretized linear systems, we first propose preconditioned iterative methods to solve them. Then we apply the D’Yakonov ADI scheme to split the linear systems and solve the obtained splitting systems by iterative methods. Two preconditioned iterative methods, the preconditioned generalized minimal residual (preconditioned GMRES) method and the preconditioned conjugate gradient normal residual (preconditioned CGNR) method, are proposed to solve relevant linear systems. By fully exploiting the structure of the coefficient matrix, we design two special kinds of preconditioners, which are easily constructed and are able to accelerate convergence of iterative solvers. Numerical results show the efficiency of our preconditioners.
Human Mobility Patterns at the Smallest Scales
Authors: Lind Pedro G. , Moreira Adriano
Published: July 2015

We present a study on human mobility at small spatial scales. Differently from large scale mobility, recently studied through dollar-bill tracking and mobile phone data sets within one big country or continent, we report Brownian features of human mobility at smaller scales. In particular, the scaling exponents found at the smallest scales is typically close to one-half, differently from the larger values for the exponent characterizing mobility at larger scales. We carefully analyze 12-month data of the Eduroam database within the Portuguese university of Minho. A full procedure is introduced with the aim of properly characterizing the human mobility within the network of access points composing the wireless system of the university. In particular, measures of flux are introduced for estimating a distance between access points. This distance is typically non-Euclidean, since the spatial constraints at such small scales distort the continuum space on which human mobility occurs. Since two different exponents are found depending on the scale human motion takes place, we raise the question at which scale the transition from Brownian to non-Brownian motion takes place. In this context, we discuss how the numerical approach can be extended to larger scales, using the full Eduroam in Europe and in Asia, for uncovering the transition between both dynamical regimes.
Computing the Ground and First Excited States of the Fractional Schrödinger Equation in an Infinite Potential Well
Authors: Duo Siwei , Zhang Yanzhi
Published: July 2015

In this paper, we numerically study the ground and first excited states of the fractional Schrödinger equation in an infinite potential well. Due to the nonlocality of the fractional Laplacian, it is challenging to find the eigenvalues and eigenfunctions of the fractional Schrödinger equation analytically. We first introduce a normalized fractional gradient flow and then discretize it by a quadrature rule method in space and the semi-implicit Euler method in time. Our numerical results suggest that the eigenfunctions of the fractional Schrödinger equation in an infinite potential well differ from those of the standard (non-fractional) Schrödinger equation. We find that the strong nonlocal interactions represented by the fractional Laplacian can lead to a large scattering of particles inside of the potential well. Compared to the ground states, the scattering of particles in the first excited states is larger. Furthermore, boundary layers emerge in the ground states and additionally inner layers exist in the first excited states of the fractional nonlinear Schrödinger equation. Our simulated eigenvalues are consistent with the lower and upper bound estimates in the literature.
Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations
Authors: Ryder C. L. , McQuaid J. B. , Flamant C. , Rosenberg P. D. , Washington R. , Brindley H. E. , Highwood E. J. , Marsham J. H. , Parker D. J. , Todd M. C. , Banks J. R. , Brooke J. K. , Engelstaedter S. , Estelles V. , Formenti P. , Garcia-Carreras L. , Kocha C. , Marenco F. , Sodemann H. , Allen C. J. T. , Bourdon A. , Bart M. , Cavazos-Guerra C. , Chevaillier S. , Crosier J. , Darbyshire E. , Dean A. R. , Dorsey J. R. , Kent J. , O'Sullivan D. , Schepanski K. , Szpek K. , Trembath J. , Woolley A.
Published: July 2015

Abstract. The Fennec climate programme aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE (Service des Avions Français Instrumentés pour la Recherche en Environnement) Falcon 20 is described, with specific focus on instrumentation specially developed for and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include (1) the first airborne measurement of dust particles sizes of up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI (Spinning Enhanced Visible Infra-Red Imager) satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in situ observations of processes in SABL clouds showing dust acting as cloud condensation nuclei (CCN) and ice nuclei (IN) at −15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold pool (haboob) issued from deep convection over the Atlas Mountains, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse-mode size distributions and AERONET (AERosol Robotic NETwork) sunphotometer retrievals under light dust loadings. These results provide insights into boundary layer and dust processes in the SHL region – a region of substantial global climatic importance.
Extended and refined multi sensor reanalysis of total ozone for the period 1970–2012
Authors: van der A R. J. , Allaart M. A. F. , Eskes H. J.
Published: July 2015

Abstract. The ozone multi-sensor reanalysis (MSR) is a multi-decadal ozone column data record constructed using all available ozone column satellite data sets, surface Brewer and Dobson observations and a data assimilation technique with detailed error modelling. The result is a high-resolution time series of 6-hourly global ozone column fields and forecast error fields that may be used for ozone trend analyses as well as detailed case studies. The ozone MSR is produced in two steps. First, the latest reprocessed versions of all available ozone column satellite data sets are collected and then are corrected for biases as a function of solar zenith angle (SZA), viewing zenith angle (VZA), time (trend), and stratospheric temperature using surface observations of the ozone column from Brewer and Dobson spectrophotometers from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC). Subsequently the de-biased satellite observations are assimilated within the ozone chemistry and data assimilation model TMDAM. The MSR2 (MSR version 2) reanalysis upgrade described in this paper consists of an ozone record for the 43-year period 1970–2012. The chemistry transport model and data assimilation system have been adapted to improve the resolution, error modelling and processing speed. Backscatter ultraviolet (BUV) satellite observations have been included for the period 1970–1977. The total record is extended by 13 years compared to the first version of the ozone multi sensor reanalysis, the MSR1. The latest total ozone retrievals of 15 satellite instruments are used: BUV-Nimbus4, TOMS-Nimbus7, TOMS-EP, SBUV-7, -9, -11, -14, -16, -17, -18, -19, GOME, SCIAMACHY, OMI and GOME-2. The resolution of the model runs, assimilation and output is increased from 2° × 3° to 1° × 1°. The analysis is driven by 3-hourly meteorology from the ERA-Interim reanalysis of the European Centre for Medium-Range Weather Forecasts (ECMWF) starting from 1979, and ERA-40 before that date. The chemistry parameterization has been updated. The performance of the MSR2 analysis is studied with the help of observation-minus-forecast (OmF) departures from the data assimilation, by comparisons with the individual station observations and with ozone sondes. The OmF statistics show that the mean bias of the MSR2 analyses is less than 1 % with respect to de-biased satellite observations after 1979.
Modelling short-term variability in carbon and water exchange in a temperate Scots pine forest
Authors: Vermeulen M. H. , Kruijt B. J. , Hickler T. , Kabat P.
Published: July 2015

Abstract. The vegetation–atmosphere carbon and water exchange at one particular site can strongly vary from year to year, and understanding this interannual variability in carbon and water exchange (IAVcw) is a critical factor in projecting future ecosystem changes. However, the mechanisms driving this IAVcw are not well understood. We used data on carbon and water fluxes from a multi-year eddy covariance study (1997–2009) in a Dutch Scots pine forest and forced a process-based ecosystem model (Lund–Potsdam–Jena General Ecosystem Simulator; LPJ-GUESS) with local data to, firstly, test whether the model can explain IAVcw and seasonal carbon and water exchange from direct environmental factors only. Initial model runs showed low correlations with estimated annual gross primary productivity (GPP) and annual actual evapotranspiration (AET), while monthly and daily fluxes showed high correlations. The model underestimated GPP and AET during winter and drought events. Secondly, we adapted the temperature inhibition function of photosynthesis to account for the observation that at this particular site, trees continue to assimilate at very low atmospheric temperatures (up to daily averages of −10 °C), resulting in a net carbon sink in winter. While we were able to improve daily and monthly simulations during winter by lowering the modelled minimum temperature threshold for photosynthesis, this did not increase explained IAVcw at the site. Thirdly, we implemented three alternative hypotheses concerning water uptake by plants in order to test which one best corresponds with the data. In particular, we analyse the effects during the 2003 heatwave. These simulations revealed a strong sensitivity of the modelled fluxes during dry and warm conditions, but no single formulation was consistently superior in reproducing the data for all timescales and the overall model–data match for IAVcw could not be improved. Most probably access to deep soil water leads to higher AET and GPP simulated during the heatwave of 2003. We conclude that photosynthesis at lower temperatures than assumed in most models can be important for winter carbon and water fluxes in pine forests. Furthermore, details of the model representations of water uptake, which are often overlooked, need further attention, and deep water access should be treated explicitly.
Effectiveness of a regional model calibrated to different parts of a flow regime in regionalisation
Authors: Kim H. S.
Published: July 2015

Abstract. The objective of this study was to reduce the parameter uncertainty which has an effect on the identification of the relationship between the catchment characteristics and the catchment response dynamics in ungauged catchments. A water balance model calibrated to represent the rainfall runoff characteristics over long time scales had a potential limitation in the modelling capacity to accurately predict the hydrological effects of non-stationary catchment response dynamics under different climate conditions (distinct wet and dry periods). The accuracy and precision of hydrological modelling predictions was assessed to yield a better understanding for the potential improvement of the model's predictability. In the assessment of model structure suitability to represent the non-stationary catchment response characteristics, there was a flow-dependent bias in the runoff simulations. In particular, over-prediction of the streamflow was dominant for the dry period. The poor model performance during the dry period was associated with the largely different impulse response estimates for the entire period and the dry period. The refined calibration approach was established based on assessment of model deficiencies. The rainfall–runoff models were separately calibrated to different parts of the flow regime, and the calibrated models for the separated time series were used to establish the regional models of relevant parts of the flow regime (i.e. wet and dry periods). The effectiveness of the parameter values for the refined approach in regionalisation was evaluated through investigating the accuracy of predictions of the regional models. The predictability was demonstrated using only the dry period to highlight the improvement in model performance easily veiled by the performance of the model for the whole period. The regional models from the refined calibration approach clearly enhanced the hydrological behaviour by improving the identification of the relationships between the catchment attributes and the catchment response dynamics representing the time constants in fitting recession parts of hydrograph (i.e. improving the parameter identifiability representing the different behaviour of the catchment) in regionalisation.
Rainfall erosivity in subtropical catchments and implications for erosion and particle-bound contaminant transfer: a case-study of the Fukushima region
Authors: Laceby J. P. , Chartin C. , Evrard O. , Onda Y. , Garcia-Sanchez L. , Cerdan O.
Published: July 2015

Abstract. The Fukushima Dai-ichi nuclear power plant (FDNPP) accident in March 2011 resulted in a significant fallout of radiocesium over the Fukushima region. After reaching the soil surface, radiocesium is almost irreversibly bound to fine soil particles. Thereafter, rainfall and snow melt run-off events transfer particle-bound radiocesium downstream. Erosion models, such as the Universal Soil Loss Equation (USLE), depict a proportional relationship between rainfall and soil erosion. As radiocesium is tightly bound to fine soil and sediment particles, characterizing the rainfall regime of the fallout-impacted region is fundamental to modelling and predicting radiocesium migration. Accordingly, monthly and annual rainfall data from ~ 60 meteorological stations within a 100 km radius of the FDNPP were analysed. Monthly rainfall erosivity maps were developed for the Fukushima coastal catchments illustrating the spatial heterogeneity of rainfall erosivity in the region. The mean average rainfall in the Fukushima region was 1387 mm yr−1 (σ 230) with the mean rainfall erosivity being 2785 MJ mm ha−1 yr−1 (σ 1359). The results indicate that the majority of rainfall (60 %) and rainfall erosivity (86 %) occurs between June and October. During the year, rainfall erosivity evolves positively from northwest to southeast in the eastern part of the prefecture, whereas a positive gradient from north to south occurs in July and August, the most erosive months of the year. During the typhoon season, the coastal plain and eastern mountainous areas of the Fukushima prefecture, including a large part of the contamination plume, are most impacted by erosive events. Understanding these rainfall patterns, particularly their spatial and temporal variation, is fundamental to managing soil and particle-bound radiocesium transfers in the Fukushima region. Moreover, understanding the impact of typhoons is important for managing sediment transfers in subtropical regions impacted by cyclonic activity.
Global terrestrial water storage connectivity revealed using complex climate network analyses
Authors: Sun A. Y. , Chen J. , Donges J.
Published: July 2015

Abstract. Terrestrial water storage (TWS) exerts a key control in global water, energy, and biogeochemical cycles. Although certain causal relationship exists between precipitation and TWS, the latter quantity also reflects impacts of anthropogenic activities. Thus, quantification of the spatial patterns of TWS will not only help to understand feedbacks between climate dynamics and the hydrologic cycle, but also provide new insights and model calibration constraints for improving the current land surface models. This work is the first attempt to quantify the spatial connectivity of TWS using the complex network theory, which has received broad attention in the climate modeling community in recent years. Complex networks of TWS anomalies are built using two global TWS data sets, a remote sensing product that is obtained from the Gravity Recovery and Climate Experiment (GRACE) satellite mission, and a model-generated data set from the global land data assimilation system's NOAH model (GLDAS-NOAH). Both data sets have 1° × 1° grid resolutions and cover most global land areas except for permafrost regions. TWS networks are built by first quantifying pairwise correlation among all valid TWS anomaly time series, and then applying a cutoff threshold derived from the edge-density function to retain only the most important features in the network. Basinwise network connectivity maps are used to illuminate connectivity of individual river basins with other regions. The constructed network degree centrality maps show the TWS anomaly hotspots around the globe and the patterns are consistent with recent GRACE studies. Parallel analyses of networks constructed using the two data sets reveal that the GLDAS-NOAH model captures many of the spatial patterns shown by GRACE, although significant discrepancies exist in some regions. Thus, our results provide further measures for constraining the current land surface models, especially in data sparse regions.