bluuebunny/crossref_metadata_2025 huggingface dataset:
Are You Convinced? Middle‐Grade Students' Evaluations of Mathematical Arguments
Authors: Bieda Kristen N. , Lepak Jerilynn
Published: April 2014

Students learn norms of proving by observing teachers generating proofs, engaging in proving, and generalizing features of proofs deemed convincing by an authority, such as a textbook. Students at all grade levels have difficulties generating valid proof; however, little research exists on students' understandings about what makes a mathematical argument convincing prior to more formal instruction in methods of proof. This study investigated middle‐school students' (ages 12–14) evaluations of arguments for a statement in number theory. Students evaluated both an empirical and a general argument in an interview setting. The results show that students tend to prefer empirical arguments because examples enhance an argument's power to show that the statement is true. However, interview responses also reveal that a significant number of students find arguments to be most convincing when examples are supported with an explanation that “tells why” the statement is true. The analysis also examined the alignment of students' reasons for choosing arguments as more convincing along with the strategies they employ to make arguments more convincing. Overall, the findings show middle‐school students' conceptions about what makes arguments convincing are more sophisticated than their performance in generating arguments suggests.
The (mis)fortunes of exceeding a small local air market: Comparing Amsterdam and Brussels
Authors: Burghouwt Guillaume , Dobruszkes Frédéric
Published: April 2014

Comparing air service growth in Amsterdam and Brussels, this paper aims to understand how the strategies of airlines and public authorities allow certain medium‐sized cities to succeed in exceeding their local market by connecting passengers, while others do not. In contrast to Brussels, Amsterdam has become one of the most air serviced European cities, reaching a highly disproportionate level of service given both its size and its airport catchment area. Amsterdam has reached its rank thanks to a successful, global hub‐and‐spokes strategy led by KLM and its partners. Such a success story would have been impossible without support from the State pursuing the expansion of numerous, liberal bilateral air service agreements and a regional development strategy which facilitated the expansion of Amsterdam Schiphol airport in the 1990s. Finally, this paper shows how public and corporate governances might be able to convert themselves to the rules of the market economy.
An Exploration of Memory‐making in the Digital Era: Remembering the FEPOW Story Online
Authors: Muzaini Hamzah , Yeoh Brenda S.A.
Published: April 2014

Symptomatic of the digital era, web‐memorials and web‐communities have become highly prevalent as a means of commemorating the past. Drawing on the analysis of fepow‐community.org.uk, an online network devoted to honouring the stories of Allied soldiers interned by the Japanese during the Second World War (also known as FEPOWs), and an online survey of its members, this paper examines the extent that such platforms facilitate more inclusionary allowances for doing so vis‐à‐vis physical sites of memory. Specifically, while web‐memorials do remedy some of the shortcomings linked to the latter, they too are plagued by criticisms limiting them as a more democratic way of remembering. It also highlights how physical sites of memory provide certain affective resonances virtual memorials do not. Consequently, both genres of memory are often capitalised upon complementarily (rather than in a mutually exclusive way) as each feeds into the other, both salient to memory work.
Integrating Spatial Data Linkage and Analysis Services in a Geoportal for China Urban Research
Authors: Zhu Xinyan , She Bing , Guo Wei , Bao Shuming , Chen Di
Published: April 2014

Many geoportals are now evolving into online analytical environments, where large amounts of data and various analysis methods are integrated. These spatiotemporal data are often distributed in different databases and exist in heterogeneous forms, even when they refer to the same geospatial entities. Besides, existing open standards lack sufficient expression of the attribute semantics. Client applications or other services thus have to deal with unrelated preprocessing tasks, such as data transformation and attribute annotation, leading to potential inconsistencies. Furthermore, to build informative interfaces that guide users to quickly understand the analysis methods, an analysis service needs to explicitly model the method parameters, which are often interrelated and have rich auxiliary information. This work presents the design of the spatial data linkage and analysis services in a geoportal for China urban research. The spatial data linkage service aggregates multisource heterogeneous data into linked layers with flexible attribute mapping, providing client applications and services with a unified access as if querying a big table. The spatial analysis service incorporates parameter hierarchy and grouping by extending the standard WPS service, and data‐dependent validation in computation components. This platform can help researchers efficiently explore and analyze spatiotemporal data online.
Adenosine receptor inhibition attenuates the suppression of postexercise cutaneous blood flow
Authors: McGinn Ryan , Fujii Naoto , Swift Brendan , Lamarche Dallon T. , Kenny Glen P.
Published: April 2014

Key points

Skin blood flow (SkBF) is an important avenue for heat loss; however, it is rapidly suppressed after exercise despite persistently high core and muscle temperatures.

This has been ascribed to altered active vasodilation; however, recent work has identified a role for adenosine receptors in the decrease in SkBF following passive heating.

In this study, we examined whether adenosine receptors are involved in the postexercise regulation of SkBF by infusion of 4 mm theophylline (a non‐selective adenosine receptor antagonist) via microdialysis.

We show that adenosine receptors have a major role in modulating postexercise SkBF, as evidenced by a marked elevation during theophylline infusion compared to a control site.

These results help us to better understand the mechanisms underlying the postexercise reduction in SkBF and subsequently heat loss which is associated with heat‐related illness and/or injury.

The time‐dependent contributions of active vasodilation (e.g. nitric oxide) and noradrenergic vasoconstriction to the postexercise suppression of cutaneous perfusion despite persistent hyperthermia remain unknown. Moreover, adenosine receptors have been shown to mediate the decrease in cutaneous perfusion following passive heating. We examined the time‐dependent modulation of nitric oxide synthase, noradrenergic vasoconstriction and adenosine receptors on postexercise cutaneous perfusion. Eight males performed 15 min of high‐intensity (85% ) cycling followed by 60 min of recovery in temperate ambient conditions (25°C). Four microdialysis probes were inserted into the forearm skin and continuously infused with: (1) lactated Ringer solution (Control); (2) 10 mm NG‐nitro‐l‐arginine methyl ester (l‐NAME; nitric oxide synthase inhibitor); (3) 10 mm bretylium tosylate (BT; inhibitor of noradrenergic vasoconstriction); or (4) 4 mm theophylline (THEO; adenosine receptor inhibitor). Cutaneous vascular conductance (CVC) was expressed as a percentage of maximum and was calculated as perfusion units (laser Doppler) divided by mean arterial pressure. End‐exercise CVC was similar in Control, THEO and BT (P > 0.1), but CVC with l‐NAME (39 ± 4%) was lower than Control (59 ± 4%, P < 0.01). At 20 min of recovery, Control CVC (22 ± 3%) returned to baseline levels (19 ± 2%, P = 0.11). Relative to Control, CVC was reduced by l‐NAME for the first 10 min of recovery whereas CVC was increased with BT for the first 30 min of recovery (P < 0.03). In contrast, CVC with THEO was elevated throughout the 60 min recovery period (P ≤ 0.01) compared to Control. We show that adenosine receptors appear to have a major role in postexercise cutaneous perfusion whereas nitric oxide synthase and noradrenergic vasoconstriction are involved only earlier during recovery.
Simulations of Anisotropic Grain Growth Involving Two-Phase Nanocrystalline/Amorphous Systems Using Q-State Monte Carlo
Authors: Allen J. B.
Published: April 2014

The present work incorporates an implementation of the two dimensional, Q-state Monte Carlo method to evaluate anisotropic grain growth in two-phase nanocrystalline/amorphous systems. Specifically, anisotropic grain boundaries are simulated via the use of surface energies and binding energies; the former attributable to the variation in grain orientation and assigned through a mapping process involving Wulff plots. The secondary, amorphous phase is randomly assigned to the lattice in accordance with a specified initial volume fraction. Among other findings, the results reveal that the grain boundary surface energy, as governed by the shape of the Wulff plot, plays a critical role in the resulting microstructure. Additionally, it was found that the addition of a secondary amorphous phase to an existing anisotropic grain boundary system evolves into primary grain microstructures characteristic of single phase isotropic systems.
A Computational Analysis of the Deformation of the Femoropopliteal Artery With Stenting
Authors: Ní Ghriallais Ríona , Bruzzi Mark
Published: April 2014

Physiological loads that act on the femoropopliteal artery, in combination with stenting, can lead to uncharacteristic deformations of the stented vessel. The overall goal of this study was to investigate the effect of stent length and stent location on the deformation characteristics of the superficial femoral artery (SFA) using an anatomically accurate, three-dimensional finite element model of the leg. For a range of different stent lengths and locations, the deformation characteristics (length change, curvature change, and axial twist) that result from physiological loading of the SFA along with the mechanical behavior of the vessel tissue are investigated. Results showed that stenting portions of the SFA leads to a change in global deformation characteristics of the vessel. Increased stress and strain values and altered deformation characteristics were observed in the various stented cases of this study, which are compared to previous results of an unstented vessel. The study concludes that shortening, twist and curvature characteristics of the stented vessel are dependent on stent length and stent location within the vessel.
Impact of Tooth Spacing Errors on the Root Stresses of Spur Gear Pairs
Authors: Handschuh M. J. , Kahraman A. , Milliren M. R.
Published: April 2014

In this study, experimental and theoretical investigations of the effect of tooth spacing errors on the root stresses of spur gear pairs are performed. A test setup with instrumentation for the measurement of root stresses has been developed. A number of experiments were performed with gears having deterministic (at one or two teeth only) and random spacing errors (all teeth having a random distribution of errors as in a typical production gear). These experiments were simulated using a deformable-body gear contact model to describe the empirical trends physically. A methodology is proposed to relate increases in root stresses to the spacing error magnitudes directly. Closed-form expressions resulting from this methodology permit the determination of the stress amplification factors due to a certain range of spacing error tolerances as well as quantifying how much spacing error can be tolerated within a user defined stress limit.
Arginine Starvation Impairs Mitochondrial Respiratory Function in ASS1-Deficient Breast Cancer Cells
Authors: Qiu Fuming , Chen Yun-Ru , Liu Xiyong , Chu Cheng-Ying , Shen Li-Jiuan , Xu Jinghong , Gaur Shikha , Forman Henry Jay , Zhang Hang , Zheng Shu , Yen Yun , Huang Jian , Kung Hsing-Jien , Ann David K.
Published: April 2014

Tumors that cannot make arginine undergo mitochondrial dysfunction in the absence of extracellular arginine and die by autophagy.
The Combination of Alisporivir plus an NS5A Inhibitor Provides Additive to Synergistic Anti-Hepatitis C Virus Activity without Detectable Cross-Resistance
Authors: Chatterji Udayan , Garcia-Rivera Jose A. , Baugh James , Gawlik Katarzyna , Wong Kelly A. , Zhong Weidong , Brass Clifford A. , Naoumov Nikolai V. , Gallay Philippe A.
Published: April 2014

Alisporivir (ALV), a cyclophilin inhibitor, is a host-targeting antiviral (HTA) with multigenotypic anti-hepatitis C virus (HCV) activity and a high barrier to resistance. Recent advances have supported the concept of interferon (IFN)-free regimens to treat chronic hepatitis C. As the most advanced oral HTA, ALV with direct-acting antivirals (DAAs) represents an attractive drug combination for IFN-free therapy. In this study, we investigated whether particular DAAs exhibit additive, synergistic, or antagonistic effects when combined with ALV. Drug combinations of ALV with NS3 protease, NS5B polymerase, and NS5A inhibitors were investigated in HCV replicons from genotypes 1a, 1b, 2a, 3, and 4a (GT1a to -4a). Combinations of ALV with DAAs exerted an additive effect on GT1 and -4. A significant and specific synergistic effect was observed with ALV-NS5A inhibitor combination on GT2 and -3. Furthermore, ALV was fully active against DAA-resistant variants, and ALV-resistant variants were fully susceptible to DAAs. ALV blocks the contact between cyclophilin A and domain II of NS5A, and NS5A inhibitors target domain I of NS5A; our data suggest a molecular basis for the use of these two classes of inhibitors acting on two distinct domains of NS5A. These results provide
in vitro
evidence that ALV with NS5A inhibitor combination represents an attractive strategy and a potentially effective IFN-free regimen for treatment of patients with chronic hepatitis C. Due to its high barrier and lack of cross-resistance, ALV could be a cornerstone drug partner for DAAs.
Activities of Ceftazidime and Avibactam against β-Lactamase-Producing Enterobacteriaceae in a Hollow-Fiber Pharmacodynamic Model
Authors: Coleman Ken , Levasseur Premavathy , Girard Anne-Marie , Borgonovi Monica , Miossec Christine , Merdjan Henri , Drusano George , Shlaes David , Nichols Wright W.
Published: April 2014

Avibactam is a novel non-β-lactam β-lactamase inhibitor that is currently undergoing phase 3 clinical trials in combination with ceftazidime. Ceftazidime is hydrolyzed by a broad range of β-lactamases, but avibactam is able to inhibit the majority of these enzymes. The studies described here attempt to provide insight into the amount of avibactam required to suppress bacterial growth in an environment where the concentrations of both agents are varying as they would when administered to humans. Following the simulation of a single intravenous dose of the drug, ceftazidime alone had no effect on any test organism, but a ceftazidime-avibactam combination resulted in rapid killing of all of the strains, with growth suppressed for the 8 h of the study. For seven of eight strains, this was achieved with a 1-g–250-mg profile, but a 2-g–500-mg profile was necessary to completely suppress a high-level-AmpC-producing isolate. When ceftazidime was infused continuously for 24 h with a single bolus dose of avibactam, rapid killing of all of the strains was again observed, with growth suppressed for 10 to >24 h. Regrowth appeared to commence once the avibactam concentration dropped below a critical concentration of approximately 0.3 μg/ml. In a third series of studies, ceftazidime was administered every 8 h for 24 h with avibactam administered at fixed concentrations for short periods during each ceftazidime dose profile. Simulating a 1-g dose of ceftazidime, an avibactam pulse of >0.25 and <0.5 μg/ml was required to suppress growth for 24 h.
Discovery of Novel Cell Wall-Active Compounds Using P

ywaC

, a Sensitive Reporter of Cell Wall Stress, in the Model Gram-Positive Bacterium Bacillus subtilis
Authors: Czarny T. L. , Perri A. L. , French S. , Brown E. D.
Published: April 2014

The emergence of antibiotic resistance in recent years has radically reduced the clinical efficacy of many antibacterial treatments and now poses a significant threat to public health. One of the earliest studied well-validated targets for antimicrobial discovery is the bacterial cell wall. The essential nature of this pathway, its conservation among bacterial pathogens, and its absence in human biology have made cell wall synthesis an attractive pathway for new antibiotic drug discovery. Herein, we describe a highly sensitive screening methodology for identifying chemical agents that perturb cell wall synthesis, using the model of the Gram-positive bacterium
Bacillus subtilis
. We report on a cell-based pilot screen of 26,000 small molecules to look for cell wall-active chemicals in real time using an autonomous luminescence gene cluster driven by the promoter of
ywaC
, which encodes a guanosine tetra(penta)phosphate synthetase that is expressed under cell wall stress. The promoter-reporter system was generally much more sensitive than growth inhibition testing and responded almost exclusively to cell wall-active antibiotics. Follow-up testing of the compounds from the pilot screen with secondary assays to verify the mechanism of action led to the discovery of 9 novel cell wall-active compounds.
Echinocandin Failure Case Due to a Previously Unreported
FKS1
Mutation in Candida krusei
Authors: Jensen Rasmus Hare , Justesen Ulrik Stenz , Rewes Annika , Perlin David S. , Arendrup Maiken Cavling
Published: April 2014

Echinocandins are the preferred therapy for invasive infections due to
Candida krusei
. We present here a case of clinical failure involving
C. krusei
with a characteristic
FKS1
hot spot mutation not previously reported in
C. krusei
that was isolated after 14 days of treatment. Anidulafungin MICs were elevated by ≥5 dilution steps above the clinical breakpoint but by only 1 step for a
Candida albicans
isolate harboring the corresponding mutation, suggesting a notable species-specific difference in the MIC increase conferred by this mutation.
Evaluation of the Pharmacokinetics and Pharmacodynamics of Liposomal Amikacin for Inhalation in Cystic Fibrosis Patients with Chronic Pseudomonal Infections Using Data from Two Phase 2 Clinical Studies
Authors: Okusanya Olanrewaju O. , Bhavnani Sujata M. , Hammel Jeffrey P. , Forrest Alan , Bulik Catharine C. , Ambrose Paul G. , Gupta Renu
Published: April 2014

The pharmacokinetic-pharmacodynamic (PK-PD) relationships between serum exposure measures of liposomal amikacin for inhalation (LAI) and the change in pulmonary function test (PFT) measures and number of CFU from baseline were evaluated in cystic fibrosis (CF) patients chronically infected with
Pseudomonas aeruginosa
. A dose of 70, 140, 280, or 560 mg of LAI or placebo was administered to CF patients once daily for 28 days. PFTs and sputum samples for microbiology were assessed on days 7, 14, 21, 28, 35 (for log
10
CFU), and 56 (for PFTs). Serum, urine, and sputum samples were collected for PK evaluation. The relationships between efficacy endpoints (relative change in forced expiratory volume in 1 s [FEV
1
{expressed in liters}] and FEV
1
% predicted and the absolute change in log
10
CFU of
P. aeruginosa
from baseline) and exposure measures (dose, day 1 area under the curve [AUC], dose/MIC ratio, and day 1 AUC/MIC ratio) and baseline MIC value were assessed. The serum and urine PK data were best fit by a 3-compartment model (lung, serum, and urine) with linear clearance and interoccasional variation on total and renal clearance. Significant univariable relationships between dose or day 1 AUC and the relative change in PFT measures (
P
≤ 0.017) or the absolute change in log
10
CFU from baseline (
P
≤ 0.037) on the study days were identified. Repeated-measures mixed-effects models, which showed dose- and AUC-related improvements for each efficacy endpoint (
P
≤ 0.041), predicted the observed data well. The increases in the relative change in FEV
1
and FEV
1
% predicted of 11% and 9.9%, respectively, and a 1.23-log
10
CFU reduction per 560 mg of LAI estimated on day 7 were comparable to the observed increases of 10.7% and 10.3%, respectively, and a 1.24-log
10
CFU reduction on the same day. The model-estimated PFT effects were predicted to be sustained to day 28. An additional 0.451-log
10
CFU reduction (
P
= 0.022) was estimated on day 14 relative to day 7, with a persistence of effect predicted to day 35.
Host Biomarkers of Invasive Pulmonary Aspergillosis To Monitor Therapeutic Response
Authors: Krel Mila , Petraitis Vidmantas , Petraitiene Ruta , Jain Mohit Raja , Zhao Yanan , Li Hong , Walsh Thomas J. , Perlin David S.
Published: April 2014

Invasive pulmonary aspergillosis (IPA) is a life-threatening disease of immunocompromised patients that requires aggressive therapy. Detection of the disease and monitoring of the therapeutic response during IPA are complex, and current molecular diagnostics are not suitably robust. Here, we explored proteomic profiles of bronchoalveolar lavage fluid (BALF) specimens from a persistently neutropenic rabbit model of IPA. Three experimental arms, uninfected control animals, infected untreated animals, and animals infected and treated with ravuconazole/amphotericin B, were studied. Total proteins were evaluated by two-dimensional (2D) gel electrophoresis, followed by matrix-assisted laser desorption ionization–time of flight/time of flight (MALDI-TOF/TOF) mass spectrometry (MS) and quantified by enzyme-linked immunosorbent assay (ELISA). Host-derived proteins haptoglobin (Hp), C-reactive protein (CRP), and annexin A1 (Anx A1) were prominently found in BALF during the IPA infection and showed significant changes in response to antifungal therapy (
P
< 0.0001). In serum, differences in Hp (
P
= 0.0001) between infected and treated rabbits were observed. Preliminary
in vitro
studies revealed that
Aspergillus fumigatus
-secreted proteases may contribute to the cleavage of Anx A1 during IPA. In summary, host protein biomarkers Hp, CRP, and Anx A1 may have value in monitoring therapeutic response to antifungal agents in IPA patients with confirmed disease.
Deoxysugars as Antituberculars and Alpha-Mannosidase Inhibitors
Authors: Kashyap Vivek , Sharma Smriti , Singh Vinayak , Sharma Sandeep K. , Saquib Mohammad , Srivastava Ranjana , Shaw Arun K.
Published: April 2014

A promising modified sugar molecule was identified which was active against multidrug-resistant (MDR) strains of
Mycobacterium tuberculosis
, suggesting involvement of a new target. The compound was demonstrated to be bactericidal, inhibited the growth of
M. tuberculosis
in mice, and targeted alpha-mannosidase as a competitive inhibitor with a

K
i

value of 353.9 μM.
Biochemical Analysis of Metallo-β-Lactamase NDM-3 from a Multidrug-Resistant Escherichia coli Strain Isolated in Japan
Authors: Tada Tatsuya , Miyoshi-Akiyama Tohru , Shimada Kayo , Kirikae Teruo
Published: April 2014

New Delhi metallo-β-lactamase-3 (NDM-3) was identified in a multidrug-resistant
Escherichia coli
isolate, NCGM77, obtained from the feces of a patient in Japan. The enzymatic activities of NDM-3 against β-lactams were similar to those of NDM-1, although NDM-3 showed slightly lower
k
cat
/

K
m

ratios for all the β-lactams tested except for doripenem. The genetic context for
bla
NDM-3
was
tnpA-bla
NDM-3
-
ble
MBL
-
trpF-dsbC-tnpA-sulI-qacEdeltaI-aadA2-dfrA1
, which was present on an approximately 250-kb plasmid.
Citrullination and Proteolytic Processing of Chemokines by Porphyromonas gingivalis
Authors: Moelants Eva A. V. , Loozen Gitte , Mortier Anneleen , Martens Erik , Opdenakker Ghislain , Mizgalska Danuta , Szmigielski Borys , Potempa Jan , Van Damme Jo , Teughels Wim , Proost Paul
Published: April 2014

The outgrowth ofPorphyromonas gingivaliswithin the inflammatory subgingival plaque is associated with periodontitis characterized by periodontal tissue destruction, loss of alveolar bone, periodontal pocket formation, and eventually, tooth loss. Potential virulence factors ofP. gingivalisare peptidylarginine deiminase (PPAD), an enzyme modifying free or peptide-bound arginine to citrulline, and the bacterial proteases referred to as gingipains (Rgp and Kgp). Chemokines attract leukocytes during inflammation. However, posttranslational modification (PTM) of chemokines by proteases or human peptidylarginine deiminases may alter their biological activities. Since chemokine processing may be important in microbial defense mechanisms, we investigated whether PTM of chemokines byP. gingivalisenzymes occurs. Upon incubation of interleukin-8 (IL-8; CXCL8) with PPAD, only minor enzymatic citrullination was detected. In contrast, Rgp rapidly cleaved CXCL8in vitro. Subsequently, differentP. gingivalisstrains were incubated with the chemokine CXCL8 or CXCL10 and their PTMs were investigated. No significant CXCL8 citrullination was detected for the tested strains. Interestingly, although considerable differences in the efficiency of CXCL8 degradation were observed with full cultures of various strains, similar rates of chemokine proteolysis were exerted by cell-free culture supernatants. Sequencing of CXCL8 incubated with supernatant or bacteria showed that CXCL8 is processed into its more potent forms consisting of amino acids 6 to 77 and amino acids 9 to 77 (the 6-77 and 9-77 forms, respectively). In contrast, CXCL10 was entirely and rapidly degraded byP. gingivalis, with no transient chemokine forms being observed. In conclusion, this study demonstrates PTM of CXCL8 and CXCL10 by gingipains ofP. gingivalisand that strain differences may particularly affect the activity of these bacterial membrane-associated proteases.
ANCA-associated vasculitis and pauci-immune glomerulonephritis in HIV disease
Authors: Evans Rhys , Gueret-Wardle Alexander , Edwards Simon , Salama Alan
Published: April 2014

We report the case of a 51-year-old African woman with longstanding well-controlled HIV who developed relapsing systemic antineutrophil cytoplasm antibody (ANCA)-associated vasculitis and glomerulonephritis. She presented with an acute kidney injury and heavy proteinuria in the setting of a prolonged history of diffuse arthralgias and transient ocular symptoms. Antimyeloperoxidase (MPO) antibody titre was >100 IU/mL. Subsequent renal biopsy demonstrated a focal necrotising pauci-immune glomerulonephritis and a diagnosis of MPO-ANCA-associated microscopic polyangiitis was made. The patient was treated with tapering glucocorticoids and rituximab with resolution of her acute kidney injury and reduction in her proteinuria. Treatment was complicated by the development of steroid-induced diabetes and one mild clinical relapse, but was otherwise well tolerated without infectious complications or deterioration in her HIV disease.
An unusual cause of small bowel obstruction in children: lentil soup bezoar
Authors: Plataras Christos , Sardianos Nektarios , Vlatakis Stephanos , Nikas Konstantinos
Published: April 2014

Bezoars are an unusual cause of acute intestinal obstruction in children. Most cases are trichobezoars in adolescent girls who swallow their hair. Lactobezoars are another unusual but occasionally reported cause of intestinal obstruction in neonates. Phytobezoars and food bolus bezoars are the least common types of intestinal obstruction that have been reported in children. Of the few paediatric cases that have been described, the majority involve persimmons. Moreover, all of these cases involve the ingestion of raw fibres or fruit that have not been cooked. We report a case of a girl who presented with acute ileal obstruction because of lentil soup bezoar. Given the wide use of this otherwise nutritional foodstuff, we highlight the danger from its inappropriate preparation to the health of children. This is the first reported case of intestinal obstruction caused by lentils in children and we hope to raise concern among paediatricians regarding this matter.
School refusal in adolescent young man: could this be an idiopathic amotivational syndrome?
Authors: Ding Jonathan , Gadit Amin Muhammad , Peer Syed Bakhtiar
Published: April 2014

This is the case of a 17-year-old male student who presented to an outpatient clinic with a 3-year episode of increasing anxiety and amotivation related to attending school. Initially affecting only his school work and attendance, the amotivation grew to affect his activities of daily living such as personal hygiene maintenance. There were no discernible psychosocial stressors. The patient did not report any bullying at school or any sort of abuse. At the time of presentation, there were also some depressive symptoms and visual perceptual abnormalities; both appeared subsequent to the amotivation. Escitalopram treated the depressive symptoms and risperidone minimised the perceptual disturbances; methylphenidate was not effective for this patient. The medications did not improve the patient's motivation. At the time of writing, the patient remained in stable state in terms of mood but unable to return to school.
Bochdalek hernia causing type II respiratory failure in an elderly patient
Authors: Jubber Ibrahim , Madani Yasser , Yousaf Siama , Jubber Akeel
Published: April 2014

Bochdalek hernias occur as a result of a congenital defect in the diaphragm enabling abdominal viscera to enter the thoracic cavity restricting lung expansion and ventilation. Bochdalek hernias, in the majority of cases, present in neonates and very rarely in adults. To the best of our knowledge, there are only four published cases of Bochdalek hernia in the adult population causing respiratory failure. We present the case of an 87-year-old woman who had three admissions in the past 6 months with type II respiratory failure due to a Bochdalek hernia which we believe was congenital but had gradually increased in size over the years to cause progressive decompensation with acute exacerbations requiring non-invasive ventilation.
High knee abduction moments are common risk factors for patellofemoral pain (PFP) and anterior cruciate ligament (ACL) injury in girls: Is PFP itself a predictor for subsequent ACL injury?
Authors: Myer Gregory D , Ford Kevin R , Di Stasi Stephanie L , Foss Kim D Barber , Micheli Lyle J , Hewett Timothy E
Published: April 2014

Background

Identifying risk factors for knee pain and anterior cruciate ligament (ACL) injury can be an important step in the injury prevention cycle.

Objective

We evaluated two unique prospective cohorts with similar populations and methodologies to compare the incidence rates and risk factors associated with patellofemoral pain (PFP) and ACL injury.

Methods

The ‘PFP cohort’ consisted of 240 middle and high school female athletes. They were evaluated by a physician and underwent anthropometric assessment, strength testing and three-dimensional landing biomechanical analyses prior to their basketball season. 145 of these athletes met inclusion for surveillance of incident (new) PFP by certified athletic trainers during their competitive season. The ‘ACL cohort’ included 205 high school female volleyball, soccer and basketball athletes who underwent the same anthropometric, strength and biomechanical assessment prior to their competitive season and were subsequently followed up for incidence of ACL injury. A one-way analysis of variance was used to evaluate potential group (incident PFP vs ACL injured) differences in anthropometrics, strength and landing biomechanics. Knee abduction moment (KAM) cut-scores that provided the maximal sensitivity and specificity for prediction of PFP or ACL injury risk were also compared between the cohorts.

Results

KAM during landing above 15.4 Nm was associated with a 6.8% risk to develop PFP compared to a 2.9% risk if below the PFP risk threshold in our sample. Likewise, a KAM above 25.3 Nm was associated with a 6.8% risk for subsequent ACL injury compared to a 0.4% risk if below the established ACL risk threshold. The ACL-injured athletes initiated landing with a greater knee abduction angle and a reduced hamstrings-to-quadriceps strength ratio relative to the incident PFP group. Also, when comparing across cohorts, the athletes who suffered ACL injury also had lower hamstring/quadriceps ratio than the players in the PFP sample (p<0.05).

Conclusions

In adolescent girls aged 13.3 years, >15 Nm of knee abduction load during landing is associated with greater likelihood of developing PFP. Also, in girls aged 16.1 years who land with >25 Nm of knee abduction load during landing are at increased risk for both PFP and ACL injury.
Mediastinectomy for management of chronic pyogranulomatous pleural disease in dogs
Authors: Trinterud T. , Nelissen P. , Caine A. R. , White R. A. S.
Published: April 2014

The medical records of 12 dogs with chronic pyogranulomatous pleural disease unresponsive to medical management were reviewed retrospectively. Resection of the mediastinal pleura (mediastinectomy) was performed through a median sternotomy to remove all diseased and surgically accessible mediastinal pleural tissue. Dogs were re‐examined two weeks postoperatively, and long‐term outcome was evaluated by contacting owners by phone. Twelve dogs underwent mediastinectomy; additional surgeries included subtotal pericardiectomy (8), lung lobectomy (4) and partial diaphragmatic resection (2). Histology of resected tissue consistently revealed neutrophilic, pyogranulomatous cellulitis/serositis. Foreign material was evident in the mediastinal tissue of five dogs and microorganisms were recovered from three dogs. Two dogs developed pneumothorax immediately postoperatively; one dog developed haemothorax one month postoperatively and was euthanased. Median follow‐up time was eight months (range: 6–43 months); eleven dogs were alive and considered to be symptom‐free by their owners. Mediastinectomy resulted in complete resolution of symptoms in most dogs (92 per cent) and was associated with a low incidence of major complications. The results of this study indicated that mediastinectomy results in favourable outcome for dogs with chronic pleural pyogranulomatous pleural disease unresponsive to medical management.
Guidelines for MSAT and SNP panels that lead to high-quality data for genetic mark–recapture studies
Authors: Sethi Suresh Andrew , Cook Geoffrey M. , Lemons Patrick , Wenburg John
Published: April 2014

Molecular markers with inadequate power to discriminate among individuals can lead to false recaptures (shadows), and inaccurate genotyping can lead to missed recaptures (ghosts), potentially biasing genetic mark–recapture estimates. We used simulations to examine the impact of microsatellite (MSAT) and single nucleotide polymorphism (SNP) marker-set size, allelic frequency, multitubes approaches, and sample matching protocols on shadow and ghost events in genetic mark–recapture studies, presenting guidance on the specifications for MSAT and SNP marker panels, and sample matching protocols necessary to produce high-quality data. Shadow events are controllable by increasing the number of markers or by selecting markers with high discriminatory power; reasonably sized marker sets (e.g., ≥9 MSATs or ≥32 SNPs) of moderate allelic diversity lead to low probabilities of shadow errors. Ghost events are more challenging to control and low allelic dropout or false-allele error rates produced high rates of erroneous mismatches in mark–recapture sampling. Fortunately, error-tolerant matching protocols, which use information from positively matching loci between comparisons of samples, and multitubes protocols to achieve consensus genotypes are effective at eliminating ghost events. We present a case study on Pacific walrus, Odobenus rosmarus divergens (Illiger, 1815), using simulation results to inform genetic marker choices.
A low cost way for assessing bird risk hazards in power lines: Fixed-wing small unmanned aircraft systems
Authors: Mulero-Pázmány Margarita , Negro Juan José , Ferrer Miguel
Published: April 2014

Accidents on power lines are one of the most important causes of man-induced mortality for raptors and soaring birds. The factors that condition the hazard have been extensively studied, and currently there are a variety of technical solutions available to mitigate the risk. Most of the resources in conservation projects to reduce avian mortality now are invested in fieldwork to monitor the lines, which diverts the resources available to install actual corrective measures to mitigate bird hazard. Little progress has been achieved in the methodology to characterize line risk, which is an expensive, tedious, and time-consuming task. In this work we describe the use of low cost small unmanned aircraft systems (sUAS) equipped with on-board cameras for power line surveillance. As a case study, we characterized four power lines, geo-referenced every pylon in selected portions, and assessed their hazard for birds. We compare the effectiveness of two variants of the sUAS method for data acquisition and two methods of plane control. This work provides evidence of the usefulness of sUAS as a fast, inexpensive, and practical tool in conservation biology, adding to their already known applications in wildlife monitoring, the environmental impact assessment of infrastructures.
UAV LiDAR for below-canopy forest surveys
Authors: Chisholm Ryan A. , Cui Jinqiang , Lum Shawn K. Y. , Chen Ben M.
Published: April 2014

Remote sensing tools are increasingly being used to survey forest structure. Most current methods rely on GPS signals, which are available in above-canopy surveys or in below-canopy surveys of open forests, but may be absent in below-canopy environments of dense forests. We trialled a technology that facilitates mobile surveys in GPS-denied below-canopy forest environments. The platform consists of a battery-powered UAV mounted with a LiDAR. It lacks a GPS or any other localisation device. The vehicle is capable of an 8 min flight duration and autonomous operation but was remotely piloted in the present study. We flew the UAV around a 20 m × 20 m patch of roadside trees and developed postprocessing software to estimate the diameter-at-breast-height (DBH) of 12 trees that were detected by the LiDAR. The method detected 73% of trees greater than 200 mm DBH within 3 m of the flight path. Smaller and more distant trees could not be detected reliably. The UAV-based DBH estimates of detected trees were positively correlated with the human-based estimates (R2= 0.45, p = 0.017) with a median absolute error of 18.1%, a root-mean-square error of 25.1% and a bias of −1.2%. We summarise the main current limitations of this technology and outline potential solutions. The greatest gains in precision could be achieved through use of a localisation device. The long-term factor limiting the deployment of below-canopy UAV surveys is likely to be battery technology.
SOME EXPERIENCES WITH SOLVING SEMIDEFINITE PROGRAMMING RELAXATIONS OF BINARY QUADRATIC OPTIMIZATION MODELS IN COMPUTATIONAL BIOLOGY
Authors: ENGAU ALEXANDER
Published: April 2014

We present two recent integer programming models in molecular biology and study practical reformulations to compute solutions to some of these problems. In extension of previously tested linearization techniques, we formulate corresponding semidefinite relaxations and discuss practical rounding strategies to find good feasible approximate solutions. Our computational results highlight the possible advantages and remaining challenges of this approach especially on large-scale problems.
SIMULATION-BASED OPTIMIZATION BY NEW STOCHASTIC APPROXIMATION ALGORITHM
Authors: XU ZI , LI YINGYING , ZHAO XINGFANG
Published: April 2014

This paper proposes one new stochastic approximation algorithm for solving simulation-based optimization problems. It employs a weighted combination of two independent current noisy gradient measurements as the iterative direction. It can be regarded as a stochastic approximation algorithm with a special matrix step size. The almost sure convergence and the asymptotic rate of convergence of the new algorithm are established. Our numerical experiments show that it outperforms the classical Robbins–Monro (RM) algorithm and several other existing algorithms for one noisy nonlinear function minimization problem, several unconstrained optimization problems and one typical simulation-based optimization problem, i.e., (s, S)-inventory problem.
Analytic Models of SSD Write Performance
Authors: Desnoyers Peter
Published: April 2014

Solid-state drives (SSDs) update data by writing a new copy, rather than overwriting old data, causing prior copies of the same data to be
invalidated
. These writes are performed in units of
pages
, while space is reclaimed in units of multipage
erase blocks
, necessitating copying of any remaining valid pages in the block before reclamation. The efficiency of this cleaning process greatly affects performance under random workloads; in particular, in SSDs, the write bottleneck is typically internal media throughput, and
write amplification
due to additional internal copying directly reduces application throughput.

We present the first nearly-exact closed-form solution for write amplification under greedy cleaning for uniformly-distributed random traffic, validate its accuracy via simulation, and show that its inaccuracies are negligible for reasonable block sizes and overprovisioning ratios. In addition, we also present the first models which predict performance degradation for both LRW (least-recently-written) cleaning and greedy cleaning under simple nonuniform traffic conditions; simulation results show the first model to be exact and the second to be accurate within 2%. We extend the LRW model to arbitrary combinations of random traffic and demonstrate its use in predicting cleaning performance for real-world workloads.

Using these analytic models, we examine the strategy of separating “hot” and “cold” data, showing that for our traffic model, such separation eliminates any loss in performance due to nonuniform traffic. We then show how a system which segregates hot and cold data into different block pools may shift free space between these pools in order to achieve improved performance, and how numeric methods may be used with our model to find the optimum operating point, which approaches a write amplification of 1.0 for increasingly skewed traffic. We examine online methods for achieving this optimal operating point and show a control strategy based on our model which achieves high performance for a number of real-world block traces.
Towards High-Performance SAN with Fast Storage Devices
Authors: Choi Jae Woo , Shin Dong In , Yu Young Jin , Eom Hyeonsang , Yeom Heon Young
Published: April 2014

Storage area network (SAN) is one of the most popular solutions for constructing server environments these days. In these kinds of server environments, HDD-based storage usually becomes the bottleneck of the overall system, but it is not enough to merely replace the devices with faster ones in order to exploit their high performance. In other words, proper optimizations are needed to fully utilize their performance gains. In this work, we first adopted a DRAM-based SSD as a fast backend-storage in the existing SAN environment, and found significant performance degradation compared to its own capabilities, especially in the case of small-sized random I/O pattern, even though a high-speed network was used. We have proposed three optimizations to solve this problem: (1) removing software overhead in the SAN I/O path; (2) increasing parallelism in the procedures for handling I/O requests; and (3) adopting the temporal merge mechanism to reduce network overheads. We have implemented them as a prototype and found that our approaches make substantial performance improvements by up to 39% and 280% in terms of both the latency and bandwidth, respectively.
The future of software engineering
Authors: Anwar Zeeshan , Bibi Nazia , Ahsan Ali
Published: April 2014

Software Engineering (SE) is a new field compared to other sciences. The term Software Engineering first appeared in late 1950s. SE from its beginning has been continuously in the process of evolution. New approaches, methods, tools and techniques are introduced frequently. The future of Software Engineering is a hot topic and every year many publications discuss the same. The focus of this paper is to explore subareas of SE, predict the possible future of SE and provide a guide to practitioners to choose their careers according to the evolution of SE.
Neural network based black box testing
Authors: Bhasin Harsh , Khanna Esha
Published: April 2014

Black Box Testing is immensely important because the source code of a module is not always available. Enterprise Resource Planning systems are also tested using Black Box Testing wherein all the test cases are not equally important. The prioritization of these test cases would be helpful in case of premature termination of testing, due to lack of resources. This paper proposes a Neural Network based method to prioritize test cases. The paper also presents guidelines for prioritizing test cases. The technique has been tested using a financial management system and the results are encouraging. This paper paves way for applying Neural Network in Black Box Testing and presents a framework, which would help both researchers and practitioners.
Agile, CMMI®, RUP®, ISO/IEC 12207...
Authors: López-Lira Hinojo Francisco José
Published: April 2014

Sometimes, a new software development project requires selecting or proposing a particular model, methodology, or method, called generically a Set of Practices (SoP). In this paper, we provide a two-dimensional model for classifying and thus better understanding where the different SoPs fit in for software development. The model is applied to 27 different SoPs and the results are used to generate basic guidelines for decision support. SoPs vary in both complexity (height) and specialization (width). The larger the area (height x width) the more time needed for implementation of the SoP. We suggest the following advice: Make sure to establish a well-planned implementation project. Make sure the SoP contains everything you need. Combining SoPs can lead to success or failure, so be careful. Consider quality, productivity and volatility of requirements in your decision. Decide whether you need an SoP for one project or permanently. Don't design an SoP yourself, at least not for the first time.
Existence and Estimates of Positive Solutions for Some Singular Fractional Boundary Value Problems
Authors: Mâagli Habib , Mhadhebi Noureddine , Zeddini Noureddine
Published: April 2014

We establish the existence and uniqueness of a positive solutionufor the following fractional boundary value problem:Dαu(x)=−a(x)uσ(x),x∈(0,1)with the conditionslimx→0+⁡x2−αu(x)=0,u(1)=0, where1<α≤2,σ∈(−1,1), andais a nonnegative continuous function on(0,1)that may be singular atx=0orx=1. We also give the global behavior of such a solution.