bluuebunny/crossref_metadata_2025_split huggingface dataset:
PLASMA-WAVE GENERATION IN A DYNAMIC SPACETIME
Authors: Yang Huan , Zhang Fan 
Published: February 2016

ABSTRACT
We propose a new electromagnetic (EM)-emission mechanism in magnetized, force-free plasma, which is driven by the evolution of the underlying dynamic spacetime. In particular, the emission power and angular distribution of the emitted fast-magnetosonic and Alfvén waves are separately determined. Previous numerical simulations of binary black hole mergers occurring within magnetized plasma have recorded copious amounts of EM radiation that, in addition to collimated jets, include an unexplained, isotropic component that becomes dominant close to the merger. This raises the possibility of multimessenger gravitational-wave and EM observations on binary black hole systems. The mechanism proposed here provides a candidate analytical characterization of the numerical results, and when combined with previously understood mechanisms such as the Blandford–Znajek process and kinetic-motion-driven radiation, it allows us to construct a classification of different EM radiation components seen in the inspiral stage of compact-binary coalescences.
A Bedside Decision Tree for Use of Saline With Endotracheal Tube Suctioning in Children
Authors: Owen Erin B. , Woods Charles R. , O’Flynn Justine A. , Boone Megan C. , Calhoun Aaron W. , Montgomery Vicki L. 
Published: February 2016

BACKGROUNDEndotracheal tube suctioning is necessary for patients receiving mechanical ventilation. Studies examining saline instillation before suctioning have demonstrated mixed results.METHODSA prospective study to evaluate whether saline instillation is associated with an increased risk of suctioning-related adverse events in patients 18 years old or younger requiring mechanical ventilation through an endotracheal tube for at least 48 hours when suctioned per protocol using a bedside decision tree.RESULTSA total of 1986 suctioning episodes (1003 with saline) were recorded in 69 patients. The most common indication for use of saline was thick secretions (87% of episodes). In 586 suctioning episodes, at least 1 adverse event occurred with increased frequency in the saline group (P &lt; .001). Normal saline was more likely to be associated with hemodynamic instability (P = .04), bronchospasm (P &lt; .001), and oxygen desaturation (P &lt; .001). Patient factors associated with adverse events include younger age (P &lt; .001), a cuffed endotracheal tube (P = .001), endotracheal tube diameter of 4.0 mm or less (P &lt; .001), respiratory or hemodynamic indication for intubation (P &lt; .001), underlying respiratory disease (P &lt; .001), and longer duration of mechanical ventilation (P &lt; .001). Saline instillation (P &lt; .001), endotracheal tube size of 4.0 mm or less (P = .03), and comorbid respiratory diseases (P = .03) were associated with an increased risk of adverse events.CONCLUSIONSSaline instillation before endotracheal tube suctioning is associated with hemodynamic instability, bronchospasm, and transient hypoxemia. Saline should be used cautiously, especially in children with a small endotracheal tube and comorbid respiratory disease.
An Adaptive Perfectly Matched Layer Method for Multiple Cavity Scattering Problems
Authors: Wu Xinming , Zheng Weiying 
Published: February 2016

AbstractA uniaxial perfectly matched layer (PML) method is proposed for solving the scattering problem with multiple cavities. By virtue of the integral representation of the scattering field, we decompose the problem into a system of single-cavity scattering problems which are coupled with Dirichlet-to-Neumann maps. A PML is introduced to truncate the exterior domain of each cavity such that the computational domain does not intersect those for other cavities. Based on the a posteriori error estimates, an adaptive finite element algorithm is proposed to solve the coupled system. The novelty of the proposed method is that its computational complexity is comparable to that for solving uncoupled single-cavity problems. Numerical experiments are presented to demonstrate the efficiency of the adaptive PML method.
Asymptotic-Preserving Scheme for the M1-Maxwell System in the Quasi-Neutral Regime
Authors: Guisset S. , Brull S. , Dubroca B. , d'Humières E. , Karpov S. , Potapenko I. 
Published: February 2016

AbstractThis work deals with the numerical resolution of the M1-Maxwell system in the quasi-neutral regime. In this regime the stiffness of the stability constraints of classical schemes causes huge calculation times. That is why we introduce a new stable numerical scheme consistent with the transitional and limit models. Such schemes are called Asymptotic-Preserving (AP) schemes in literature. This new scheme is able to handle the quasi-neutrality limit regime without any restrictions on time and space steps. This approach can be easily applied to angular moment models by using a moments extraction. Finally, two physically relevant numerical test cases are presented for the Asymptotic-Preserving scheme in different regimes. The first one corresponds to a regime where electromagnetic effects are predominant. The second one on the contrary shows the efficiency of the Asymptotic-Preserving scheme in the quasi-neutral regime. In the latter case the illustrative simulations are compared with kinetic and hydrodynamic numerical results.
Patch-Recovery Filters for Curvature in Discontinuous Galerkin-Based Level-Set Methods
Authors: Kummer Florian , Warburton Tim 
Published: February 2016

AbstractIn two-phase flow simulations, a difficult issue is usually the treatment of surface tension effects. These cause a pressure jump that is proportional to the curvature of the interface separating the two fluids. Since the evaluation of the curvature incorporates second derivatives, it is prone to numerical instabilities. Within this work, the interface is described by a level-set method based on a discontinuous Galerkin discretization. In order to stabilize the evaluation of the curvature, a patch-recovery operation is employed. There are numerous ways in which this filtering operation can be applied in the whole process of curvature computation. Therefore, an extensive numerical study is performed to identify optimal settings for the patch-recovery operations with respect to computational cost and accuracy.
On the Disclination Lines of Nematic Liquid Crystals
Authors: Hu Yucheng , Qu Yang , Zhang Pingwen 
Published: February 2016

AbstractDefects in liquid crystals are of great practical importance and theoretical interest. Despite tremendous efforts, predicting the location and transition of defects under various topological constraint and external field remains to be a challenge. We investigate defect patterns of nematic liquid crystals confined in three-dimensional spherical droplet and two-dimensional disk under different boundary conditions, within the Landau-de Gennes model. We implement a spectral method that numerically solves the Landau-de Gennes model with high accuracy, which allows us to study the detailed static structure of defects. We observe five types of defect structures. Among them the 1/2-disclination lines are the most stable structure at low temperature. Inspired by numerical results, we obtain the profile of disclination lines analytically. Moreover, the connection and difference between defect patterns under the Landau-de Gennes model and the Oseen-Frank model are discussed. Finally, three conjectures are made to summarize some important characteristics of defects in the Landau-de Gennes theory. This work is a continuing effort to deepen our understanding on defect patterns in nematic liquid crystals.
Do Transfer Costs Matter for Foreign Remittances? A Gravity Model Approach
Authors: Ahmed Junaid , Martínez-Zarzoso Inmaculada 
Published: February 2016

Abstract
Using bilateral data on remittance flows to Pakistan for 23 major host countries, this is the first study that examines the effect of transaction costs on foreign remittances. The authors find that the effect of transaction costs on remittance flows is negative and significant; suggesting that a high cost will either refrain migrants from sending money back home or make them remit through informal channels. They also find that remittances are facilitated by the existence of migrant networks and improvements in home and host country financial services. Distance, which has been used in previous studies as an indicator of the cost of remitting, is found to be a poor proxy.
Mars MOURA magnetometer demonstration for high resolution mapping on terrestrial analogues
Authors: Diaz Michelena Marina , Kilian Rolf , Sanz Ruy , Rios Francisco , Baeza Oscar 
Published: February 2016

Abstract. Satellite-based magnetic measurements of Mars indicate complex and very strong magnetic	anomalies, which	led	to	an	intensive	and long-lasting	discussion about their possible origin. To investigate the origin of these anomalies MOURA vector magnetometer	was	developed for future	on	ground	surveys on	Mars	and tested	on various terrestrial analogues characterised by most distinct magnetic anomalies of their basement rocks: (1) A magnetite body of EL Laco (up to +110 000 nT) and its transition to surrounding andesites (< +2000 nT) in the Northern Andes of Chile showing the highest local magnetic anomalies. The magnetite-bearing ore body has highly variable local anomalies due to their complex formation history where a significant dispersion in paleo-orientations has been previously reported, while our vector	data show	relatively	uniform and	probably	induced	declinations.	(2)	A basaltic spatter	cone of the	Pali	Aike	volcanic	field,	in	Southern	Chile, was	characterised	by very strong	magnetic	anomalies along	the crater rim (up	to	+12 000	nT), controlled by	the amount	of	single	domain	magnetites	in	the	ground	mass	of	the	basalts. Due	to	their strong remanent signature paleodeclinations of the lavas and reorientations of collapsed blocks could be constrained by the vector data. (3) The Monturaqui meteorite	crater (350 m	diameter),	in	Northern Chile, shows significant variations	of	its anomalies (from −2000	to	> +6000	nT)	in	restricted	areas	of	several square metres along	its crater	rim	related	to unexposed iron-bearing	fragments of	the	impactor while its granitic	and	ignimbritic target	rocks	exhibit	only	very	weak	anomalies. (4) An	area with several amphibolitic dykes which cross-cut a Cretaceous granitoid in the southernmost	Andes,	where a	decimetre-scale	mapping	was	performed. In	this	case, pyrr hotite is	the only	magnetic	carrier.	It	was formed during	hydrothermal	processes within	the	dykes.	Very	low	(+40	to	+120 nT)	positive	magnetic	anomalies	clearly	depict the amount of 1 to 4 vol. % pyrrhotite in these dykes, which is important as a mineralogical	indicator	as	well	as to	detect	associated	gold	and	copper	enrichment.
Pupil Response to Tropicamide following Corneal Crosslinking
Authors: Kymionis George D. , Paraskevopoulos Theodore A. , Liakopoulos Dimitrios A. , Grentzelos Michael A. , Kouroupaki Anna I. , Tsoulnaras Konstantinos I. , Panagopoulou Sophia I. , Mazzotta Cosimo , Detorakis Efstathios T. 
Published: February 2016

Purpose To evaluate the effect of corneal crosslinking (CXL) with ultraviolet A (UVA) irradiation on pupil response to tropicamide 0.5% instillation. Methods This prospective interventional study enrolled 17 patients (19 eyes) with progressive keratoconus who underwent CXL with UVA irradiation. Central corneal thickness (CCT) was evaluated with the use of anterior segment optical coherence tomography (Visante OCT 3.0). Pupil diameter was measured with the use of Colvard infrared pupillometer before the instillation of tropicamide 0.5% and after the instillation of tropicamide every 5 minutes for total duration of 30 minutes. Corneal epithelial integrity was examined with the use of fluorescein dye staining. Measurements were performed 1 day preoperatively and 1 month postoperatively, with emphasis on simulating the same light conditions regarding the pupil measurements. Results No intraoperative or postoperative complications were observed in any of the patients. Mean CCT decreased significantly (p<0.001) 1 month postoperatively. Mean postoperative pupil size did not change significantly at any time point compared to the mean preoperative measurements. Conclusions The CXL procedure seems not to impair effectiveness of topical drugs, using pupil size measurements after tropicamide 0.5% instillation.
Surgical treatment of congenital clubfoot deformity: The Qatar experience
Authors: Bakdash M. M. , Al Yazidi S. , Al Said M. N. 
Published: February 2016

This was a retrospective study analyzing surgical treat-ment of rigid, non-teratologic talipes equinovarus (club foot deformity) in Qatar in the ten year period from 1990 to 1999. Treatment started early (as soon as the patient was referred, usually during the first two - three weeks of de-livery) with serial manipulation and adhesive strapping or plaster of paris casting. When clinically indicated, soft tis-sue release was performed.
One hundred and twenty one feet were operated upon in Hamad General Hospital during that period. (73 patients, 46 male, 27 female). Postero-medial release was done in 73 feet; Achilles tendon lengthening in eight feet; posterior release in 32 feet. Most primary soft tissue procedures were performed between two and ten months of age. Primary bony procedures were done for eight feet with late presentation.
Posterior release alone resulted in a higher rate of secondary procedures (53%), whereas postero-medial release resulted in only 22%. Therefore we recommend postero-medial release whenever in doubt about the adequacy of posterior release.
Resuscitation Guidelines Update: Adult Basic Life Support
Authors: Salam A. M. , AI Musleh A. W. , Gehani A. A. 
Published: February 2016

The International Guidelines 2000 Conference on Cardiop-ulmonary Resuscitation and Emergency Cardiovascular Care was the world's first international conference to produce evi-dence-based international resuscitation guidelines.
Herein, we summarize the changes in these guidelines as it applies to Adult Basic Life Support (BLS). This interpretation is basically similar to that of the European Resuscitation Coun-cil (ERC). The changes have been incorporated into the cur-riculum of our Advanced Life Support (ALS) provider courses and the new 2001 ERC ALS manual.
The Outcome of In-Vitro Fertilization/Intracytoplasmic Sperm Injection (IVF/ICSI) Cycles Complicated by Moderate-Severe Ovarian Hyperstimulation Syndrome (OHSS)
Authors: Al Inizi S. T. , Asaad M. , Schick J. 
Published: February 2016

A retrospective study was used in the Fertility Clinic of the Department of Obstetrics & Gynecology, Tawam Hospital, Al Ain, Abu Dhabi, United Arab Emirates to determine the outcome of IVF/ICSI cycles complicated by OHSS.
Materials & Methods: In the period between January 1994 and August 2000, 3174 IVF/ICSI cycles were performed and 2918 cycles had reached embryo transfer, 564 women achieved pregnancy (19.33%). 92 women (3.15%) developed moderate-severe OHSS and were hospitalized and their medical and IVF records were reviewed. Supportive management whilst waiting for the condition to resolve spontaneously together with follow-up by ultrasound scan and blood tests was applied to all patients included in the study. Pregnancy test was performed 17 days after ovum pick-up.
Results: Ninety-two women developed moderate-severe OHSS, 37 women of them had a clinical pregnancy (40.2%). 51.4% were singletons and 48.6% were multiple pregnancies; including 13 sets of twins, 4 sets of triplets and one set of quadruplets. The miscarriage rate was 32.4% and the spontaneous fetal reduction rate was 16.6%. 25 women continued pregnancy (67.6%); eleven women had preterm delivery (44%), low birth weight rate was 44% and take home baby rate was 59.4%. The Cesarean section rate was 24%. Pregnancy-induced hypertension rate was only 8% and gestational diabetes 4%. There were no cases of ectopic pregnancy or placental abruption.
Conclusion: The pregnancy rate and the rate of multiple pregnancy, miscarriage, prematurity, low birth weight and Cesarean section rate are significantly higher than those reported previously for pregnancies conceived with the use of assisted reproductive techniques without the development of OHSS. The incidence of other obstetric complications such as pregnancy-induced hypertension, gestational diabetes, abruptio placentae and ectopic pregnancy are not significantly different.
Selected Abstracts From Other Journals
Authors: Hammoudeh M. , Gehani A. A. 
Published: February 2016

Context: There is a paucity of effective, well-tolerated drugs available for migraine prophylaxis.
Objective: To determine whether treatment with the angiotensin II receptor blocker candesartan is effective as a migraine-prophylactic drug.
Design and Setting: Randomized, double-blind, placebo-controlled crossover study performed in a Norwegian neurological outpatient clinic from January 2001 to February 2002.
Patient: Sixty patients aged 18 to 65 years with 2 to 6 migraine attacks per month were recruited mainly from newspaper advertisements.
Interventions: A placebo run-in period of 4 weeks was followed by two 12-week treatment periods separated by 4 weeks of placebo washout. Thirty patients were randomly assigned to receive one 16-mg candesartan cilexetil tablet daily in the first treatment period followed by 1 placebo tablet daily in the second period. The remaining 30 received placebo followed by candesartan.
A Population Based Study on Mishaps During Laparoscopic Cholecystectomy in Qatar: 10 Years Experience
Authors: Hussein A. A. , Allam H. , Kassem H. , Sholeik N. 
Published: February 2016

In order to determine the national incidence of adverse events following laparoscopic cholecystectomy (LC) the records were reviewed retrospectively of4861 patients who underwent LC over a period often years (1993-2003).
The most serious non-biliary complication was trocar injury of major vessels in three cases. Other non-biliary complications included duodenal perforation during dis-section of the Calot's triangle, small bowel injury while inserting the umbilical port and trocar site hernia. Adverse biliary events included common bile duct injury, common hepatic duct injury, bile leakage from the cystic duct and one instance of the migration of an endoloop into the com-mon bile duct. Conversion to open cholecystectomy was required in 109 cases.
Although LC may be associated with various adverse sequelae, these are rare and should not deter surgeons and patients.
Non-Enhanced Spiral CT Versus Excretory Urography in Acute Renal Colic
Authors: Uraiqat A. , Al Khateeb M. , Al Shishani J. 
Published: February 2016

Objective: To evaluate the usefulness of non-enhanced spiral CT (NECT) and compare it with that of excretory urography (EU) in patients with acute flank pain.
Methods: Ninety five patients presenting with acute flank pain underwent both NECT and EU. Both techniques were used to determine the presence, size, and location of urinary stone, and the presence or absence of secondary signs was also evaluated. The existence of ureteral stone was confirmed by its removal or spontaneous passage during follow-up. The absence of a stone was determined on the basis of the clinical and radiological evidence.
Result: Seventy eight of the 95 patients had one or more ureteral stones and 17 had no stones. CT depicted 79 of 83 calculi in the 78 patients with a stone and no calculus in all seventeen without a stone. The sensitivity and specificity of NECT were 95% and 100%, respectively. EU disclosed 73 calculi in the 78patients with a stone and no calculus in fifteen of the seventeen without a stone, with sensitivity and specificity 89% and 88% respectively.
Conclusion: For the evaluation of patients with acute flank pain, NECT is an excellent modality with high sensitivity and specificity. In near future it may replace EU.
An Assessment of Five Year Experience in Amniocentesis in Qatar
Authors: Al Tamimi H. , Al Sakka M. , Lilia A. R. , Selmy O. 
Published: February 2016

Objective: The purpose of this study is to evaluate the risk of foetal loss attributable to amniocentesis and to assess the experience in technique, successful fluid aspiration in amniocentesis performed in our hospital Study Design: Medical record of 123 women who underwent amniocentesis between September 1996 till March 2002 were reviewed for indication, maternal, age, nationality, maternal age, parity, nationality, gestational age at procedure, physician operator, amniotic fluid reports and pregnancy outcome.
Result: Within 30 days of amniocentesis there were tow (2.2%) foetal lossess, 91 patients (74%) for genetic amniocentesis, 32 patients (26%) Rh. Isoimmunization, 4 cases (3.2%) no fluid aspiration and in 10 patients procedure repeated one week later for successful aspiration.
Conclusion: Amniocentesis-related total pregnancy loss rate was 2.2%. Successful aspiration of clear amniotic fluid increases with amniocentesis experience.
Intravitreal Injection of Triamcinolone Acetonide for the Treatment of Refractory Diabetic Macular Edema
Authors: El Shafei M. M. , Martinez F. E. , Al Hashimi M. , Allaftah F. W. , Farouq M. 
Published: February 2016

A prospective! descriptive! non-comparative pilot study was used to evaluate the efficacy of intravitreal injection of triamcinolone acetonide (TA) for the treatment of patients with refractory diabetic macular edema that had not responded to laser treatment. Forty eyes of 35 patients with visual acuity (VA) < 6/12 were infected with TA 4 mgl 0.1 cc under topical anesthesia. Results were assessed and analyzed using changes in visual acuity (VA), retinal thickness (RT) and macular volume measured by optical coherence tomography (OCT). In 62.85 % of cases the VA improved by more than two Snellen's lines, the initial VA (mean! log MAR) being 0.67 changing to 0.31 after six months (p = 0.008). RT improved in all patients, having the most remarkable improvement in the Macular Volume, with a decrease of 2.7 mm3 at the end of the study (p = 0.009). Both improvement ofVA and RT were more marked during the early follow-up. The most common complication was ocular hypertension (OHT) in 22.5 % of eyes, all of which responded to medical antiglaucoma treatment. Intravitreal injection ofTA looks to be a useful option for the treatment of refractory diabetic macular edema.
Antenatal Corticosteroids and Outcome in a Very Low Birth Weight in Qatar
Authors: Kurdi B.A. , Hoover K.J. 
Published: February 2016

Respiratory Distress Syndrome (RDS) causes significant mortality and morbidity in babies born before 32 weeks gestation. To determine the effectiveness of antenatal steroid treatment (ANS) in reducing neonatal morbidity from respiratory distress syndrome, and patent ductus arteriosus (PDA), intra-ventricular haemorrhage (IVH), and retinopathy of prematurity (ROP) in very low birth weight infants, a retrospective case control study examined the medical records of 125 babies born before 32 weeks gestation. Divided into two groups according to whether or not antenatal corticosteroids were given, the groups did not differ in rates of RDS, IVH, PDA, or ROP but the group that did not receive ANS had a significantly higher risk of death (p < 0.05).