bluuebunny/crossref_metadata_2025 huggingface dataset:
Detecting rare variants for complex traits using family and unrelated data
Authors: Zhu Xiaofeng , Feng Tao , Li Yali , Lu Qing , Elston Robert C.
Published: October 2009

Large genome‐wide association studies (GWAS) have been performed to detect common genetic variants involved in common diseases, but most of the variants found this way account for only a small portion of the trait variance. Furthermore, candidate gene‐based resequencing suggests that many rare genetic variants contribute to the trait variance of common diseases. Here we propose two designs, sibpair and unrelated‐case designs, to detect rare genetic variants in either a candidate gene‐based or genome‐wide association analysis. First we show that we can detect and classify together rare risk haplotypes using a relatively small sample with either of these designs, and then have increased power to test association in a larger case‐control sample. This method can also be applied to resequencing data. Next we apply the method to the Wellcome Trust Case Control Consortium (WTCCC) coronary artery disease (CAD) and hypertension (HT) data, the latter being the only trait for which no genome‐wide association evidence was reported in the original WTCCC study, and identify one interesting gene associated with HT and four associated with CAD at a genome‐wide significance level of 5%. These results suggest that searching for rare genetic variants is feasible and can be fruitful in current GWAS, candidate gene studies or resequencing studies. Genet. Epidemiol. 34: 171–187, 2010. © 2009 Wiley‐Liss, Inc.
Sediment budget of the Napo River, Amazon basin, Ecuador and Peru
Authors: Laraque A. , Bernal C. , Bourrel L. , Darrozes J. , Christophoul F. , Armijos E. , Fraizy P. , Pombosa R. , Guyot J. L.
Published: October 2009

The upstream‐downstream sediment budget along the Napo River (100 520 km2, 6300 m3 s−1) was studied in the Andean foothills of Ecuador, at the west of the Amazon basin. A comparative study was made during four hydrological cycles (2001–2005) for three hydrological stations located upstream, and during one hydrological cycle (2004–2005) for the fourth one located near the mouth of the Napo River (region of Iquitos in Peru). This analysis showed an unusual increase in the concentration of suspended sediment recorded for the western part of the Amazon plain. Like the runoff (81 l s−1 km2), which is a world's maximum, the erosion rate (1160 t km−2 year−1, i.e. 47% of total suspended solid (TSS) export at the exit of Ecuador), one of the highest for a floodplain basin is the result of a stepper slope than in the rest of the Andean foothills, where typically sedimentation phenomena are predominant, and can be explained in part by a greater tectonic activity. Similar phenomenes were evidenced in small mountainous rivers in New Guinea (Milliman and Syvitski, 1992; Milliman, 1995).

On the headwaters of the Napo River drainage basin, the tectonic uplift causes the Pastaza Megafan's existence. This progressively diverts the course of Napo River towards north and also provokes the remobilization of fine fluvial deposits. Moreover, this geodynamic trend is completed by the impact of volcanic eruption, earthquakes and landslides. The combination of these phenomena, so common in the region, has provided a large sediment transfer, not only at present but also in the past, as can be confirmed by the presence of incised terraces, mainly formed by volcanic materials.

Then, these results were compared with a similar study carried out further south in the Madeira basin at the Bolivian foothills. These studies show the spatio‐temporal variability of the relation between sediment transfer and geodynamic processes at the Andean Piedmont. Copyright © 2009 John Wiley & Sons, Ltd.
Letter in response to “Identifying Lynch syndrome” by de la Chapelle et al.
Authors: Jenkins Mark A. , Dowty James G. , Hopper John L. , Tucker Kathy , Southey Melissa C.
Published: October 2009

No abtract.
A locus on chromosome 8 controlling tumor regionality—a new type of tumor diversity in the mouse lung
Authors: Quan Lei , Hutson Alan , Demant Peter
Published: October 2009

Regional specificity of lung tumor formation has rarely been studied in mouse or human. By using crosses of strains semi‐congenic for lung cancer susceptibility locus Sluc20, we have analyzed the genetic influences of Sluc20 and 5 other loci on tumor regionality in the mouse lung. We have mapped Sluc20 to a 27.92‐MB proximal region of chromosome 8 and found that it controls the number and load of only those tumors that surround or are directly adjacent to the bronchi or bronchioli (peribronchial tumors). These tumors lie outside the bronchial basement membrane and tend to reach a larger size than the tumors at other locations in the lung. Similar to tumors of alveolar lineage at other locations, peribronchial tumors stain with SP‐C but not CC10 antibody. The effects of Sluc20 alleles are additive because the number of peribronchial tumors in heterozygotes is intermediate. These findings show that tumor regionality in the mouse lung, which represents a novel level of lung tumor heterogeneity, is under specific genetic control. The identification of genes controlling lung tumor regionality will provide novel insights into the biology of lung tumors and potentially improve the possibilities of individualized prognosis and treatment in human lung cancer.
Expression and prognostic significance of iNOS in uveal melanoma
Authors: Johansson C. Christian , Mougiakakos Dimitrios , Trocme Eric , All‐Ericsson Charlotta , Economou Mario A. , Larsson Olle , Seregard Stefan , Kiessling Rolf
Published: October 2009

Uveal melanoma (UM) is the most common primary intraocular tumor in adults. Disease metastasis occurs in half of the patients and is uniformly fatal despite systemic therapy. Inducible nitric oxide synthase (iNOS) is associated with disease progression in various malignancies including cutaneous melanoma. In this retrospective cohort, we examined the prognostic value of iNOS in UM by performing immunohistochemistry on paraffin‐embedded sections of primary tumors (90 patients) and matched primary and metastatic hepatic tumors (19 patients) with complete histopathological and clinical data. We show that iNOS is expressed in UM (57% of the patients) and high iNOS levels significantly (p = 0.04; hazard ratio (HR) = 2.3) predict disease‐specific survival (DSS) as assessed by Kaplan‐Meier analysis and univariate Cox's proportional hazards regression model. Furthermore, high iNOS expression in the UM primary tissue was significantly associated with metastatic disease and vice versa. Expression of iNOS in hepatic metastases significantly (p = 0.02) predicted a shortened survival as assessed by Kaplan‐Meier analysis. However, iNOS did not appear to be a significant (p = 0.16; HR = 1.9) factor in the multivariate Cox's regression analysis performed together with the clinical parameters tumor diameter, tumor cell type, and tumor location in which only tumor diameter predicted DSS. In conclusion, iNOS predicts DSS in UM and may play a role in disease progression but it is not an independent prognostic factor.
Post‐partum testosterone administration does not reverse the effects of perinatal exposure to cadmium on rat offspring development
Authors: Couto‐Moraes R. , Felicio L. F. , Bernardi M. M.
Published: October 2009

This study investigated the effects of perinatal cadmium exposure on physical and reflexologic development of pup rats. It was examined if the immediate postpartum testosterone administration was able to reverse the toxic effects of the metal. Forty Wistar pregnant rats were divided into three groups: control and 10 and 20  mg  kg−1 per day of cadmium chloride. These dams were treated from gestational days 18 to 21, and until the 7th lactation day. Immediately after birth, half of the offspring from the experimental and control groups received 50  µL of testosterone 0.2% i.p. The maternal body weight gain, food and water consumption were measured during the treatment period. In pups, the body weight, body length, physical landmarks, reflex development and the general activity were assessed. Results showed that: only 20  mg  kg−1 cadmium induced maternal toxicity; pup body weight and body weight gain were reduced in all experimental groups; only the cadmium‐exposed offspring not treated with testosterone treatment showed a reduction in body length and body length gain; cadmium highest dose reduced the anogenital index in pups and delayed physical and reflexes development; and cadmium effects on the offspring, except in body length gain, were not reversed by testosterone. The results indicate that perinatal maternal exposure to cadmium promoted changes in the development of male rat offspring, reprogramming the pup's development. Testosterone administration was not able to reverse the cadmium effects, even on those parameters more directly related to the androgenic system as the testis descent and anogenital distance delays. Copyright © 2009 John Wiley & Sons, Ltd.
Metals in human placenta: focus on the effects of cadmium on steroid hormones and leptin
Authors: Stasenko Sandra , Bradford Elease M. , Piasek Martina , Henson Michael C. , Varnai Veda M. , Jurasović Jasna , Kušec Vesna
Published: October 2009

Cadmium and other metallic ions can act as metalloestrogens and endocrine disruptors of reproductive tissues and fetal development in mammals, including humans. The detrimental effects occur with respect to the synthesis of both steroid and polypeptide hormones in the placenta. Leptin is produced by the trophoblast and may regulate fetal organogenesis and development. In human term placentas, concentrations of toxic metals and their effects on steroidogenesis were assessed in healthy parturients (109 non‐smokers and 99 smokers) in relation to tobacco smoking. Trace elements (cadmium, lead, iron, zinc and copper) were analyzed in placentas using atomic absorption spectroscopy, and steroid hormones (progesterone and estradiol) were assayed in placental samples by an enzyme‐immunometric method. Cadmium concentrations were doubled in placentas of smokers as compared with non‐smokers, and placental lead and zinc concentrations increased significantly. Placental concentrations of iron, copper, progesterone and estradiol did not differ. In addition, human trophoblast cells were co‐cultured with 0, 5, 10 or 20  µm CdCl2 for 96  h and leptin mRNA assessed by quantitative polymerase chain reaction. Leptin mRNA declined dose‐responsively as a result of CdCl2 exposure. Collectively, the results confirm that human placental tissue offers a unique opportunity to biomonitor cadmium exposure in both the maternal and the internal fetal environments. In addition, the results strongly suggest that cadmium may cause a decline in placental leptin synthesis, as we have previously shown for placental progesterone production. This may constitute further evidence of the endocrine‐disrupting effects of cadmium, as a constituent of tobacco smoke, on reproduction in women. Copyright © 2009 John Wiley & Sons, Ltd.
In vivo imaging of hematopoietic stem cells and their microenvironment
Authors: Celso Cristina Lo , Wu Juwell W. , Lin Charles P.
Published: October 2009

In this review we provide a description of the basic concepts and paradigms currently constituting the foundations of adult stem cell biology, and discuss the role that live imaging techniques have in the development of the field. We focus on live imaging of hematopoietic stem cells (HSCs) as the basic biology and clinical applications of HSCs have historically been at the forefront of the stem cell field, and HSC are the first mammalian tissue stem cells to be visualized in vivo using advanced light microscopy techniques. We outline the current technical challenges that remain to be overcome before stem cells and their niche can be more fully characterized using the live imaging technology. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A compound QM/MM procedure: Comparative performance on a pyruvate formate‐lyase model system
Authors: Condic‐Jurkic Karmen , Zipse Hendrik , Smith David M.
Published: October 2009

We present an ONIOM(G3:MM) method as an example of a technique capable of producing chemical accuracy in the quantum mechanical (QM) treatment with a molecular mechanical description context. By applying the method to small model systems, in which we are also able to calculate the pure QM G3‐type results, it is possible to establish the reliability of the method as it applies to evaluating reaction mechanisms. By choosing small model systems that are relevant to the substrate mechanism of pyruvate formate‐lyase, we are also able to discuss the inhibitory effect of oxamate and the relevance of an alternative H‐abstraction mechanism in that context. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Multicanonical ab inito QM/MM molecular dynamics simulation of a peptide in an aqueous environment
Authors: Jono Ryota , Watanabe Yuusuke , Shimizu Kentaro , Terada Tohru
Published: October 2009

We developed a multicanonical ab initio QM/MM molecular dynamics simulation method to enhance conformational sampling of biomolecules in an aqueous environment. We applied this method to an alanine dipeptide immersed in a sphere of explicit water molecules. The peptide and the water molecules were treated by the QM method at the HF/3‐21G level and by the MM method, respectively. The van der Waals interactions between the peptide and the water molecules were calculated at the MM level, while the electrostatic interaction terms between them were incorporated into the QM Hamiltonian to account for the effect of the solvent on the electronic structure of the peptide. The simulation was performed for 1 ns, and a free‐energy map was calculated with respect to the peptide conformation. All the conformations (C5, PII, C7eq, and αR) that have been experimentally suggested to exist in solution formed basins on the free‐energy surface. Analysis of the water distribution revealed that the αR conformation was stabilized by the interaction between the large electric dipole moments of this peptide conformation and the water electric dipole moments, whereas the PII conformation was stabilized by the formation of characteristic hydrogen bonds with the water molecules. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Temperature dependence of structure and dynamics of the hydrated Ca2+ ion according to ab initio quantum mechanical charge field and classical molecular dynamics
Authors: Lim Len Herald V. , Pribil Andreas B. , Ellmerer Andreas E. , Randolf Bernhard R. , Rode Bernd M.
Published: October 2009

Simulations using ab initio quantum mechanical charge field molecular dynamics (QMCF MD) and classical molecular dynamics using two‐body and three‐body potentials were performed to investigate the hydration of the Ca2+ ion at different temperatures. Results from the simulations demonstrate significant effects of temperature on solution dynamics and the corresponding composition and structure of hydrated Ca2+. Substantial increase in ligand exchange events was observed in going from 273.15 K to 368.15 K, resulting in a redistribution of coordination numbers to lower values. The effect of temperature is also visible in a red‐shift of the ion‐oxygen stretching frequencies, reflecting weakened ligand binding. Even the moderate increase from ambient to body temperature leads to significant changes in the properties of Ca2+ in aqueous environment. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Vibrational spectroscopic studies and computational study of methyl(2‐methyl‐4,6–dinitrophenylsulfanyl)ethanoate
Authors: Panicker C. Yohannan , Raj Asha , Varghese Hema Tresa , Raju K. , Sheena Mary Y.
Published: October 2009

FT‐IR and FT‐Raman spectra of methyl(2‐methyl‐4,6–dinitrophenylsulfanyl)ethanoate (MDIE) were recorded and analyzed. Surface‐enhanced Raman scattering (SERS) spectra were recorded in silver colloid and silver electrode. The vibrational wavenumbers were computed using HF/6‐31G* and B3LYP/6‐31G* basis. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands obtained in infrared and Raman spectroscopies as well as in SERS of the studied molecule. The first hyperpolarizability and infrared intensities are reported. The geometrical parameters of the title compound are in agreement with the reported similar derivatives. The presence of new bands at 1045 and 948 cm−1 in the SERS spectrum in silver electrode is related to the change in orientation of the molecule with respect to the metal surface. In silver colloid SERS spectrum, the methyl group attached to the methoxy carbonyl group is close to the metal surface, whereas on silver electrode the methyl group attached to the phenyl ring is close to the metal surface. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and properties of polystyrene‐g‐mSiO2 filled polypropylene nanocomposites
Authors: Cai Aiyun , Zhang Shilian , Zhu Aiping , Dai Sheng
Published: October 2009

Hydrophobically modified nanosilica was prepared from tetraethoxysilane (TEOS) and γ‐methacryloxypropyltrimethoxysilane (MPS) by a two step sol‐gel process. The polystyrene‐grafted‐modified nanosilica (PS‐g‐mSiO2) hybrid particles were prepared by grafting polystyrene onto the resulting hydrophobically modified nanosilica by dispersion polymerization. The hybrid nanoparticles were subsequently used as the filler to fabricate polypropyrene (PP) nanocomposites. The crystallization kinetics, crystal morphology and crystallization phase component of PS‐g‐mSiO2/PP nanocomposite were studied using a differential scanning calorimeter (DSC), polarizing optical microscopy (POM) and X‐ray diffraction (XRD). Crystallization half life (t1/2) decreased, while the Arami exponent (n) of PS‐g‐mSiO2/PP nanocomposite increased compared with that of virgin PP. A rheological study allowed the unambiguous characterization of the dispersibility of nanosilicas in PS‐g‐mSiO2/PP nanocomposite. The storage modulus, melt viscosity and the elongation to break of the PS‐g‐mSiO2/PP nanocomposite were found to be strongly dependent on the grafting of PS on nanosilicas. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Issues in monitoring medication effects in the classroom
Authors: Anderson Laura , Walcott Christy M. , Reck Sarah G. , Landau Steven
Published: October 2009

The task of medication monitoring in the schools has increased for school psychologists, yet there is little research specific to pediatric psychoactive medication. The current article reviews issues pertinent to school‐based medication monitoring. Feasibility, acceptability, and perception of effectiveness are reviewed as fundamental considerations before implementing a medication‐monitoring plan in the schools. The importance of individualization, ecological implementation, and development of socially valid objectives is stressed along with the need for additional research, tools, and measures in this area. Practical considerations for school psychologists include discussion of parental consent and confidentiality, multilevel assessment and monitoring, data recording, and determining clinical significance. © 2009 Wiley Periodicals, Inc.
Prescription drug abuse
Authors: Hamilton Gloria J.
Published: October 2009

This article presents current statistics on nonmedical use of both categories of prescription medications by high school and college students. The incidence of nonmedical use of prescription medications continues to increase among high school and college students. Two categories of drugs that are commonly used for reasons other than those for which the drugs are prescribed are those used for pain and those prescribed for Attention‐Deficit/Hyperactivity Disorder. Demographic and behavioral characteristics of students who are most likely to engage in intentional abuse of stimulants and pain medications as well as stated motivations for use are presented. © 2009 Wiley Periodicals, Inc.
Measurements of current‐voltage characteristics of separate single GaAs nanowhiskers
Authors: Dunaevskiy Mikhail , Dementyev Petr , Egorov Vyacheslav , Polyakov Nikolay , Samsonenko Yuri , Cirlin George , Titkov Alexander
Published: October 2009

In this work a method is proposed for measurements of current‐voltage (I‐V) characteristics for individual semiconductor nanowhiskers (NWs) standing on the growth surface. It is shown that conductive probe of atomic force microscope (AFM) can be placed at the top of nanowhiskers with a great precision and used as a stable local electrode. For that, a fixation of NWs is necessary to avoid lateral bending of NWs under pressure of AFM probe. In the present work we have studied current‐voltage characteristics of NWs with radial heterostructure GaAs/AlGaAs grown under Au droplets on GaAs substrate. For fixation, NWs were partially overgrown with GaAs layer. The current‐voltage characteristics measurements on the fixed NWs permitted to investigate the Si‐doping of GaAlAs/GaAs NWs. They were found to be Schottky barrier p‐type curves, what shows that Si‐atoms incorporate into GaAs NWs with a formation of acceptor centres contrary to the case of bulk GaAs. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Advanced materials for light emitting diodes: noise characterisation
Authors: Palenskis Vilius , Matukas Jonas , Pralgauskaitė Sandra , Šaulys Bronius , Laučius Juozas
Published: October 2009

Comprehensive investigation of optical and electrical characteristics of nitride‐based (InGaN) light emitting diodes (LEDs), and comparison of the results with those for phosphide‐based (AlInGaP) are presented. The main attention was pointed to investigation of the optical and electrical fluctuations and their correlation. It is shown that correlation factor between optical and electrical fluctuations is very sensitive to device defectiveness. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Specific response of ultra‐thin metal oxide films to gas
Authors: Šetkus Arūnas , Bukauskas Virginijus , Mironas Audružis , Senulienė Daiva , Strazdienė Viktorija
Published: October 2009

Tin and indium oxide ultra‐thin film (UTF) based structures are investigated in the present study. Current‐voltage characteristics (IVC) are measured in the samples by a contact current mode of scanning probe microscopy (SPM). It is proved that the IVC splits into two paths corresponding to increase and decrease of applied voltage, respectively. Detailed investigations of the electrical properties of the ultra‐thin metal oxide (MOX) films revealed a dependence of the IVC on the structure of the films, on initial conductivity and on the surrounding gases. It was proved that the IVC is typically split only if the maximum dc‐voltage exceeds some critical magnitude that is not the same in indium and tin oxide based films. The properties of the ultra‐thin MOX structures are explained in terms of distribution of stoichiometry in MOX based nanometer systems. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐temperature MBE‐grown GaBiAs layers for terahertz optoelectronic applications
Authors: Pačebutas Vaidas , Bertulis Klemensas , Bičiūnas Andrius , Krotkus Arūnas
Published: October 2009

Gallium bismide arsenide epitaxial layers were grown by molecular‐beam‐epitaxy at low substrate temperatures and investigated for their suitability in terahertz optoelectronic applications. Optical pump‐terahertz probe measurements on these layers have shown that carrier dynamics can be described using two characteristic times. The faster decay component has characteristic times shorter than 1 ps, whereas the slower component decays in several tens of picoseconds. Fitting the electron lifetimes dependence on optical excitation level the electron trapping cross‐section and trap density were determined. The possible mechanism of carrier recombination was discussed. The photoconductive terahertz emitters and detectors made from GaBiAs layers have been manufactured and used in time‐domain spectroscopy system with a signal bandwidth larger than 4.5 THz. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Merging percolation on Zd and classical random graphs: Phase transition
Authors: Turova Tatyana S. , Vallier Thomas
Published: October 2009

We study a random graph model which is a superposition of bond percolation on Zd with parameter p, and a classical random graph G(n,c/n). We show that this model, being a homogeneous random graph, has a natural relation to the so‐called “rank 1 case” of inhomogeneous random graphs. This allows us to use the newly developed theory of inhomogeneous random graphs to describe the phase diagram on the set of parameters c ≥ 0 and 0 ≤ p < pc, where pc = pc(d) is the critical probability for the bond percolation on Zd. The phase transition is of second order as in the classical random graph. We find the scaled size of the largest connected component in the supercritical regime. We also provide a sharp upper bound for the largest connected component in the subcritical regime. The latter is a new result for inhomogeneous random graphs with unbounded kernels. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2010
Effects of annealing temperature on electrical and structural properties of Mo/n‐InP (100) Schottky contacts
Authors: Janardhanam V. , Ashok Kumar A. , Rajagopal Reddy V. , Narasimha Reddy P.
Published: October 2009

The electrical, structural and surface morphological properties of Mo/n‐InP Schottky diodes have been investigated as a function of annealing temperature using current–voltage (I–V), capacitance–voltage (C–V), Secondary Ion Mass Spectroscopy (SIMS), X‐ray diffraction (XRD) and atomic force microscopy (AFM) measurements. The obtained Schottky barrier heights from I–V and C–V measurements for as‐deposited Mo/n‐InP are 0.45 eV and 0.61 eV respectively. Upon annealing at 300 °C in nitrogen atmosphere for 1 min, the barrier height values increased to 0.47 eV (I–V) and 0.68 eV (C–V). When the samples are annealed at temperatures 400 and 500 °C, the barrier height values decrease to 0.46 eV (I–V), 0.44 eV (I–V) and 0.65 eV (C–V), 0.64 eV (C–V). The SIMS and XRD results showed the formation of phosphide phases at the Mo/n‐InP interface, which may be the reason for the decrease in the barrier height for samples annealed at 500 °C. The AFM measurements showed that the surface morphology of Mo contacts on n‐InP is smooth with a root mean square value of 12.7 nm even after annealing at 500 °C. Copyright © 2009 John Wiley & Sons, Ltd.
Communication protocols for vehicularad hocnetworks
Authors: Casteigts Arnaud , Nayak Amiya , Stojmenovic Ivan
Published: October 2009

Vehicular networks are envisioned for large scale deployment, and standardization bodies, car manufacturers, and academic researchers are solving a variety of related challenges. After a brief description of intelligent transportation system (ITS) architectures and the main already‐established low‐level standards, this tutorial elaborates on four particular aspects of vehicular networks, which are (i) the potential for a large set of innovative applications, (ii) a review of the main modeling approaches used for both roads and traffic, and finally two important communication primitives, that are (iii) data disseminationviabroadcasting/geocasting, and (iv) routing in both highway and urban environments. A particular emphasis is on recent protocols that realistically consider the inherently complex nature of vehicular mobility, such as intermittent connectivity, speed variability, and the impact of intersections. Copyright © 2009 John Wiley & Sons, Ltd.
Survey of Emergency and Surgical Capacity in the Conflict‐Affected Regions of Sri Lanka
Authors: Taira Breena R. , Cherian Meena N. , Yakandawala Harischandra , Kesavan R. , Samarage S. M. , DeSilva Mohan
Published: October 2009

Background

Three decades of internal conflict in the North and East of Sri Lanka have taken a toll on the health care system in that area.

Methods

We proposed to quantify the current status of capacity to deliver emergency, anesthesia, and surgical interventions in the conflict affected areas of Sri Lanka. The World Health Organization (WHO) Tool for Situational Analysis to Assess Emergency and Essential Surgical Care (EESC) was used to evaluate 47 health facilities.

Results

Although most have trained health care providers capable of basic procedures, infrastructure and supplies were severely lacking.

Conclusion

These data can be used as a basis for the recovery and rebuilding of EESC capacity in conflict‐affected areas of Sri Lanka.
Endothelin‐1 as a neuropeptide: neurotransmitter or neurovascular effects?
Authors: Dashwood Michael R. , Loesch Andrzej
Published: October 2009

Endothelin‐1 (ET‐1) is an endothelium‐derived peptide that also possesses potent mitogenic activity. There is also a suggestion the ET‐1 is a neuropeptide, based mainly on its histological identification in both the central and peripheral nervous system in a number of species, including man. A neuropeptide role for ET‐1 is supported by studies showing a variety of effects caused following its administration into different regions of the brain and by application to peripheral nerves. In addition there are studies proposing that ET‐1 is implicated in a number of neural circuits where its transmitter affects range from a role in pain and temperature control to its action on the hypothalamo‐neurosecretory system. While the effect of ET‐1 on nerve tissue is beyond doubt, its action on nerve blood flow is often ignored. Here, we review data generated in a number of species and using a variety of experimental models. Studies range from those showing the distribution of ET‐1 and its receptors in nerve tissue to those describing numerous neurally‐mediated effects of ET‐1.
Contract Law in International Commercial Arbitration: The Case of Suspension of Performance
Authors: Karton Joshua
Published: October 2009

Despite much attention to the controversial lex mercatoria, international commercial arbitration remains underanalysed as a venue for contract law unification. This article considers a specific case of substantive contract law in arbitration, the remedy of suspension of performance: When will one party's non-performance enable the other party to withhold performance without terminating the contract? In domestic laws, suspension of performance is governed by clearly-defined doctrines; however, it remains unclear whether it constitutes a general principle of international law. This article places suspension in a comparative context, then analyses the published arbitral awards for indications of arbitrators' preferences.
An Automatic Collision Avoidance and Guidance System for Marine Vehicles in Confined Waters
Authors: Dove M. J. , Burns R. S. , Stockel C. T.
Published: October 2009

There can be little doubt that the overall standards of safety at sea are high, particularly with the traditional maritime nations. Cockcroft states that of a total of 22600 ships over 1000 g.r.t trading in 1979, 9400 were from the traditional maritime nations. He goes on to say that during the period 1977–9 these countries lost 16 ships out of a total of 189 worldwide losses. Thus the traditional maritime nations ran 41·59 per cent of the ships and incurred only 8·4 per cent of the losses. This does suggest that high standards are not universal and there may be considerable resentment among operators of high standard ships when casualties to sub-standard vessels result in the implementation of measures, such as marine traffic management systems, which give rise to increased operating costs.
Military Flight Checking of Navigation and Landing Aids
Authors: Radforth M. A.
Published: October 2009

Civil airways route structures are constructed around en-route and terminal navigation aids such as VOR, DME and ILS. Radio navaids do not always provide accurate information to aircraft and their performance can be seriously degraded by system drift, electronic interference and unrelated changes to the local environment such as man-made obstructions erected in the beam forming area. To ensure efficient and safe operation of air traffic control, ground-based aids must be commissioned and maintained to stringent specifications at all times. Consequently, regular airborne performance checks of all radio/radar navigation aids are essential, and since the most critical time of any flight is the approach and landing phase, the precision aids (PAR and ILS) are checked at regular intervals and with a greater positional accuracy than the general navigation aids.
Mobile Satellite Communications and Navigation
Authors: Lundberg Olof
Published: October 2009

Mobile satellite communications and navigation are, historically and technically, intertwined. This paper offers a historical perspective on this interrelationship to see if the past provides some guidance to the future.
Accurate and Reliable Long-range Dynamic Radiolocation using GPS and DGPS—Geoloc Hybridization
Authors: Nard Georges
Published: October 2009

Present and future marine navigation requirements have been analysed recently for different categories of users. This paper relates to those navigation applications which need very high real-time accuracy, high availability and reliability of navigation information. This domain is mainly influenced by marine surveying and navigation community needs such as oil and mineral prospecting, hydrography and future prospecting of maritime economic zones, which are usually of high strategic or economic importance. The majority of identified needs for this limited community of users call for real-time accuracy and repeatability of instantaneous positioning ranging from 2 to 10 m, distances from shore up to 1500 km (water depth 300–1000 m), update rate of position information of a few seconds, and availability and reliability of position information data of 99 per cent or more. To reach such stringent requirements none of the existing means and even new satellites or Earth-based acoustic or radio aids individually can solve the problem. This leads to the necessity of combination or hybridization of several means which together may approach the solution.
Omega in the Land Environment
Authors: Stratton Andrew
Published: October 2009

Omega is one of a wide range of navigational aids that have been developed and are in everyday use by ships and aircraft. By contrast, outside the military field as yet there has been no significant application of these aids to mobile land vehicles. The reason has been a mismatch between the perceived accuracy requirements of the potential user, what he is prepared to pay, and what technology could provide.
Recent Developments in Automatic Steering of Ships
Authors: van Amerongen J. , van Nauta Lemke H. R.
Published: October 2009

This paper describes modern autopilots for ships. The development of modern optimal and adaptive control theories, together with the availability of inexpensive and fast digital computer systems, makes possible the design of more sophisticated controllers, which achieve better steering and save fuel. Autopilots which simultaneously control the yaw and roll motions are now being developed. In the near future it is to be expected that advanced track-prediction and track-keeping systems will facilitate the navigation and further contribute to fuel savings. The paper was presented at a Workshop held by the Netherlands branch of the Institute on 21 February 1986.
Radar Simulator Training for Inland Waterway Shipping
Authors: Breedveld D.
Published: October 2009

It was on the river Rhine that radar started its inland waterway career, followed almost immediately by the inland waterways in the Netherlands. In those days the inland waterway fleet was composed of ships owned by a few large companies and ships owned by their skippers.
Analysis of Radar PAD Information and a Suggestion to Reshape the PAD
Authors: Zhao-lin Wu
Published: October 2009

Potential points of collision (PPC) and predicted areas of danger (PAD) are used in marine radars for assessment of risk of collision and of action to avoid collision. Both are useful concepts for automatic radar plotting aids (ARPA) which lead to a better understanding of collision avoidance. The PAD display, developed by Sperry Ltd, is a graphic form3 alternative to the vector display. More information can be obtained from the PAD display than from the vector display but additional knowledge is necessary for the mariner to correctly interpret and use the information. The IMO Resolution on ARPA Performance Standards emphasizes the need for deck officers to understand the basic principles involved in the use of the equipment. In this paper consideration will be given to the information obtained from the PAD display and a suggestion will be made for possible improvement of the shape of the PAD.
Some Notes on the Navigation of 1985 Trans-Indian Ocean Canoe Voyage
Authors: McGrath W. H.
Published: October 2009

In mid-1985 the 20 metre outrigger canoeSarimanok, built in the Southern Philippines from tropical forest materials, sailed out of Bali, Indonesia, to follow the direct east-west Indian Ocean track which the first Austronesian settlers of Madagascar may have taken.
Aspects of the Soviet Union' s Glonass Satellite Navigation System
Authors: Daly P.
Published: October 2009

Global satellite navigation systems have been under development by the United States and the Soviet Union for many years. The US Navstar GPS system saw its first launch in 1978 and the USSR's Glonass system followed 4 years later. The US space shuttle, which was foreseen as the launch vehicle for Navstar spacecraft, received an enormous setback in 1986 as a result of the Challenger accident. In the meantime, Glonass launches, which carry three spacecraft at once into orbit, have proceeded without incident (until the failure on 24 April 1987). Both systems are currently still in test phase and can be expected to reach operational status in 3 or 4 years' time. In the meantime, the idea of combining Navstar and Glonass into a single civil programme has many attractions for all concerned. Some aspects of Glonass orbital characteristics and signal structure are discussed with this end in view. In addition, features of the data message content of Navstar and Glonass are also compared, to gain a better understanding of the feasibility of a dual satellite navigation system.
The Progressive Improvement of European Flow-Management
Authors: Edwards Brian
Published: October 2009

The paper has defined the objectives of flow-management, the techniques it uses, its present organization and the existing problems. It has covered the plans which have been made to radically improve the service and has described the final goal as we can see it from this point, together with the interim development phases.
Alternative Strategies for Traffic Flow-Management in Europe
Authors: Ratcliffe S.
Published: October 2009

This paper attempts to challenge some of the principles on which en-route airspace is presently allocated, whilst pointing out the practical difficulties of implementing any alternative strategy. The paper does not discuss airport capacity limitations and terminal area problems, although these also contribute to restrictions on traffic flow.
Position: Just What Does it Mean?
Authors: Cross P. A.
Published: October 2009

In the past, it was perfectly satisfactory for navigators to operate with little regard for the exact meaning of the terms, such as latitude and longitude, or even height, that they used to describe where they were. Latitude was latitude and longitude was longitude and that was the end of the matter. Of course, the positioning methods employed and the objectives of the positioning activity itself were usually so approximate that exact definitions were not important anyway, and no difficulties arose.
Integrated Communications and Navigation Terminal
Authors: Beach M. A. , Mattos P. G. , Chau M.
Published: October 2009

The mobile radio communications industry has recently witnessed a new demand for terminal equipment which can provide both communications and position reporting capabilities on a global scale–for example, the automatic monitoring of secure cargoes during international transportation. Thus, there is much interest in the development of land mobile satellite terminal equipment in the form of a single integrated unit which can economically provide both of these facilities. In this paper the development of such a unit is considered using the Inmarsat-c satellite communications service and the Navstar Global Positioning System (GPS), with extension to GLONASS possible in a receive-only version.
Estimation Accuracy of Close Approach Probability for Establishing a Radar Separation Minimum
Authors: Nagaoka Sakae , Amai Osamu
Published: October 2009

A Long-range Secondary Surveillance Radar (LSSR) has been developed and recently used as an Oceanic Route Surveillance Radar (ORSR) in Japan. The LSSR is an SSR (Secondary Surveillance Radar) only system for which the maximum coverage is 250 nautical miles (n.m.). This system utilizes monopulse azimuth estimation techniques for improving the accuracy of azimuth estimation.
European Studies to Investigate the Feasibility of Using 1000 ft Vertical Separation Minima above FL 290 Part I
Authors: Cox M. E. , ten Have J. M. , Forrester D. A.
Published: October 2009

Primarily in response to airline pressures for fuel economies, ICAO, the International Civil Aviation Organization, established a study programme early in the 1980s to determine the feasibility of halving the vertical separation minimum (VSM) used above FL 290 to 1000 ft. This paper is the first of a 3-part article describing a European contribution to this programme. After outlining the aims and organization of the experimental work, it describes the choice of methodology available to measure height-keeping errors and gives an indication of the measurement accuracy achieved. Details of the data collections, the risk calculations performed and the factors found to affect height-keeping accuracy are given in Parts II and III. Overall, the work has shown that whereas it would be technically feasible to introduce a 1000-ft VSM in the North Atlantic region, other measures would be necessary before it could be used in continental airspace. Today, in certain areas, the need for a reduced VSM has become even more pressing in order to achieve the gains in airspace capacity necessary to handle rapidly growing volumes of air traffic.
Pilot Books, Sailing Guides and Charts for Yachtsmen
Authors: Kerr Adam J.
Published: October 2009

This paper was presented on 20 February 1991 at a half-day meeting on haven charts for yachtsmen. The meeting was organized by the RIN in association with the Honourable Company of Master Mariners, the Royal Cruising Club and the Cruising Association. Adam Kerr is a Director of the International Hydrographic Bureau, but the opinions provided in this paper are his own and should not necessarily be construed to be those of his organization.
The Creative Use of Electronic Charts
Authors: Edmonds David
Published: October 2009

There is a great sense of movement and progress in navigation today. The excitement lies in the ability to do things which were not possible with traditional media or at best were difficult and time-consuming to achieve. So this paper is not about the desirability nor the timescale of the ECDIS (Electronic Chart and Display Information System) replacing paper charts for primary navigation. It is about the flexibility and creative power opened up by new technology.
The Avoidance of Collisions for Newtonian Bodies with Hidden Variables
Authors: Bramson B. D.
Published: October 2009

The collision avoidance of a pair of uniformly moving bodies is considered in three dimensions. The relative motion of the bodies yields an expression relating the time to closest approach, the minimum range, the current range and its rate of change, other variables being unobservable. A Boolean relation is then proposed that is satisfied whenever the minimum range and time to closest approach simultaneously fall below given thresholds. The relation is further studied, in particular with regard to the issue of false and premature alarms. An airborne collision avoidance system is a possible application.
Analysis of Stand-alone Differential GPS for Precision Approach
Authors: Braff Ronald , Loh Robert
Published: October 2009

Recently, there has been wide-spread interest in the use of the Global Positioning System (GPS) for precision approaches in a civil aviation environment. However, most of the work to date in Europe and North America has treated a GPS/inertial reference system (IRS) combination as the source of guidance for this phase of flight. Since the US has a very large general aviation population, the FAA is very interested in determining the role of a stand-alone implementation of differential GPS (DGPS) as a navigation sensor for precision approaches. This paper has two parts: a summary of the analysis of this application of DGPS; and a discussion of the navigation satellite test bed that is under development at the FAA's Technical Center.

The first part contains proposed accuracy, integrity and availability operational requirements, and their air traffic implications. A stand-alone DGPS concept is developed, and analysed. The major results of the analysis indicate that stand-alone DGPS may not fully meet Category I (CAT I) accuracy requirements. The results of the analysis are then used to provide the rationale for the major recommendation: that FAA pursue an implementation of a wide-area DGPS (WADGPS) to achieve a Near CAT I precision approach capability. The second part of the paper discusses the three-phase navigation satellite experimental programme that is being developed to acquire the data to validate the enhancements to GPS, including a GPS Integrity Channel (GIC) and WADGPS. The objectives of each of the experimental phases are presented and discussed. Then the experiments of Phase I that address GIC/WADGPS are discussed.
The Navigational Background to 1492
Authors: Richey Michael
Published: October 2009

Columbus's first voyage to America has been widely regarded as a considerable feat of navigation. Feat it certainly was, but the great advances in navigation during the fifteenth century were in fact made by the Portuguese, whose adaptation and development of Mediterranean methods to the more demanding requirements of the ocean made the European voyages of discovery possible. It was in Portugal too, probably during the years 1478–85, that Columbus acquired his knowledge of navigation. This paper, which was presented to a meeting at Brown University, USA on 26 September 1989, where the author was Gulbenkian Research Fellow at the John Carter Brown Library, examines navigational practice in the Mediterranean during the late middle ages and its subsequent development during the Great Age of Discovery.
On Loxodromic Navigation
Authors: Carlton-Wippern Kitt C.
Published: October 2009

This article addresses the mathematical foundations of rhumblines or loxodrome curves. These curves are critical to navigation and small-scale charting by virtue of the fact that they provide an efficient routeing from one point on a surface to another by means of a constant ‘course angle‘. This article will develop the necessary mathematical relations for the construction of such a curve, then apply the relations to both spherical and oblate-spheroidal surfaces. The purpose of this article is to produce a superior oblate-spheroidal loxodrome curve, which better models curves or routes of constant course on the actual, approximately oblatespheroidal, Earth.
Options for Control and Navigation of Unmanned Aircraft
Authors: Gardner P. , Day C. R.
Published: October 2009

Whilst unmanned aircraft (UMA) can be said to encompass missiles, targets for weapon training, preprogrammed reconnaissance drones and civilian systems such as radio-controlled models used to carry cameras, for the purpose of this paper we will restrict ourselves to aircraft which are capable of sustaining autonomous flight and accepting navigation commands whilst airborne. The terms applied to unmanned aircraft are variously UMA, remotely piloted vehicle (RPV), Drone and Unmanned Aerial Vehicle (UAV).