bluuebunny/crossref_metadata_2025 huggingface dataset:
Setaria cervidual specific phosphatase: characterization and its effect on eosinophil degranulation
Authors: RATHAUR S. , RAI R. , SRIKANTH E. , SRIVASTAVA S.
Published: June 2009

Setaria cervi, a bovine filarial parasite contains significant acid phosphatase (AcP) activity in its various life stages. Two forms of AcP were separated from somatic extract of adult female parasite using cation exchange, gel filtration and concavalin affinity chromatography. One form having a molecular mass of 79 kDa was characterized as dual specific protein tyrosine phosphatase (ScDSP) based on substrate specificity and inhibition studies. With various substrates tested, it showed significant activity in the order of phospho-L-tyrosine>pNPP>ADP>phospho-L-serine. Inhibition by orthovanadate, fluoride, molybdate, and zinc ions further confirms protein tyrosine phosphatase nature of the enzyme. Km and Vmax determined with various substrates were found to be 16·66 mM, 25·0 μM/ml/min with pNPP; 20·0 mM, 40·0 μM/ml/min with phospho-L-tyrosine and 27·0 mM, 25·0 μM/ml/min with phospho-L-serine. KIwith pNPP and sodium orthovanadate (IC5033·0 μM) was calculated to be 50·0 mM. Inhibition with pHMB, silver nitrate, DEPC and EDAC suggested the presence of cysteine, histidine and carboxylate residues at its active site. Cross-reactivity withW. bancrofti-infected sera was demonstrated by Western blotting. ScDSP showed elevated levels of IgE in chronic filarial sera using ELISA. Underin vitroconditions, ScDSP resulted in increased effector function of human eosinophils when stimulated by IgG, which showed a further decrease with increasing enzyme concentration. Results presented here suggest thatS. cerviDSP should be further studied to determine its role in pathogenesis and the persistence of filarial parasite.
Rhabdias pseudosphaerocephalainfection inBufo marinus: lung nematodes reduce viability of metamorph cane toads
Authors: KELEHEAR C. , WEBB J. K. , SHINE R.
Published: June 2009

Cane toads (Bufo marinus) were introduced to Australia in 1935 and have since spread widely over the continent, generating concern regarding ecological impacts on native predators. Most Australian cane toad populations are infected with lung nematodesRhabdias pseudosphaerocephala, a parasite endemic to New World (native-range) cane toad populations; presumably introduced to Australia with its toad host. Considering the high intensities and prevalence reached by this parasite in Australian toad populations, and public ardour for developing a control plan for the invasive host species, the lack of experimental studies on this host-parasite system is surprising. To investigate the extent to which this lungworm influences cane toad viability, we experimentally infected metamorph toads (the smallest and presumably most vulnerable terrestrial phase of the anuran life cycle) with the helminth. Infected toads exhibited reduced survival and growth rates, impaired locomotor performance (both speed and endurance), and reduced prey intake. In summary,R. pseudosphaerocephalacan substantially reduce the viability of metamorph cane toads.
Involvement of the β-adrenergic system in the cardiac chronic form of experimentalTrypanosoma cruziinfection
Authors: LO PRESTI M. S. , RIVAROLA H. W. , FERNÁNDEZ A. R. , ENDERS J. E. , LEVIN G. , FRETES R. , CERBAN F. M. , GARRIDO V. V. , PAGLINI-OLIVA P.
Published: June 2009

Changes in the cardiac β-adrenergic system in early stages ofTrypanosoma cruziinfection have been described. Here, we studied an early (135 days post-infection–p.i.) and a late stage (365 days p.i.) of the cardiac chronic form of the experimental infection (Tulahuen or SGO-Z12 strains), determining plasma epinephrine and norepinephrine levels, β-receptor density, affinity and function, cardiac cAMP concentration and phosphodiesterase activity, cardiac contractility, and the presence of β-receptor autoantibodies. Tulahuen-infected mice presented lower epinephrine and norepinephrine levels; lower β-receptor affinity and density; a diminished norepinephrine response and higher cAMP levels in the early stage, and a basal contractility similar to non-infected controls in the early and augmented in the late stage. The Tulahuen strain induced autoantibodies with weak β-receptor interaction. SGO-Z12-infected mice presented lower norepinephrine levels and epinephrine levels that diminished with the evolution of the infection; lower β-receptor affinity and an increased density; unchanged epinephrine and norepinephrine response in the early and a diminished response in the late stage; higher cAMP levels and unchanged basal contractility. The SGO-Z12 isolate induced β-receptor autoantibodies with strong interaction with the β-receptors. None of the antibodies, however, acted a as β-receptor agonist. The present results demonstrate that this system is seriously compromised in the cardiac chronic stage ofT. cruziinfection.
Past and future: vaccination againstEimeria
Authors: McDONALD V. , SHIRLEY M. W.
Published: June 2009

Eimeriaspp. are the causative agents of coccidiosis, a major disease affecting many intensively-reared livestock, especially poultry. The chicken is host to 7 species ofEimeriathat develop within intestinal epithelial cells and produce varying degrees of morbidity and mortality. Control of coccidiosis by the poultry industry is dominated by prophylactic chemotherapy but drug resistance is a serious problem. Strongly protective but species-specific immunity can be induced in chickens by infection with any of theEimeriaspp. At the Institute of Animal Health in Houghton, UK in the 1980s we showed that all 7Eimeriaspp. could be stably attenuated by serial passage in chickens of the earliest oocysts produced (i.e. the first parasites to complete their endogenous development) and this process resulted in the depletion of asexual development. Despite being highly attenuated, the precocious lines retained their immunizing capacity. Subsequent work led to the commercial introduction of the first live attenuated vaccine, Paracox®, that has now been in use for 20 years. As much work still remains to be done before the development of recombinant vaccines becomes a reality, it is likely that reliance upon live, attenuated vaccines will increase in years to come.
Evaluation and application of potential schistosome-associated morbidity markers within large-scale mass chemotherapy programmes
Authors: WEBSTER J. P. , KOUKOUNARI A. , LAMBERTON P. H. L. , STOTHARD J. R. , FENWICK A.
Published: June 2009

A primary objective of schistosomiasis control programmes is to achieve, and hence also demonstrate, a quantifiable reduction in schistosome-associated morbidity as a consequence of chemotherapeutic intervention. Inherent within such an objective, it is necessary to define and validate direct and indirect indicators of schistosome-related morbidity. However, to define and thereby document such morbidity, and its reduction following treatment, may not be straightforward, particularly for intestinal schistosomiasis-induced morbidity, which is often not apparent in all but the most severe or chronic cases. Within all ‘Schistosomiasis Control Initiative’ activities, across selected sub-Saharan African countries since 2002, a range of standard and novel potential morbidity markers have been monitored and evaluated. Parasitological intensity measures, combined with haemoglobin/anaemia counts and ultrasonography, proved valuable schistosomiasis-related morbidity indicators, being both logistically practical and informative. Additional measures tested, such as albumin excretion profiles, were promising, and are subject to ongoing research, whilst some measures, such as distended stomach/umbilical circumference, anthropometrics and health questionnaires proved less reliable. These results serve to both illustrate the success of current control activities in reducing schistosome-induced morbidity, and to highlight key tools and techniques for continued application within ongoing and future mass drug administration programmes.
Factors affecting Culicoides species composition and abundance in avian nests
Authors: MARTÍNEZ-de la PUENTE J. , MERINO S. , TOMÁS G. , MORENO J. , MORALES J. , LOBATO E. , TALAVERA S. , SARTO i MONTEYS V.
Published: June 2009

Mechanisms affecting patterns of vector distribution among host individuals may influence the population and evolutionary dynamics of vectors, hosts and the parasites transmitted. We studied the role of different factors affecting the species composition and abundance of Culicoides found in nests of the blue tit (Cyanistes caeruleus). We identified 1531 females and 2 males of 7 different Culicoides species in nests, with C. simulator being the most abundant species, followed by C. kibunensis, C. festivipennis, C. segnis, C. truncorum, C. pictipennis and C. circumscriptus. We conducted a medication×fumigation experiment randomly assigning bird's nests to different treatments, thereby generating groups of medicated and control pairs breeding in fumigated and control nests. Medicated pairs were injected with the anti-malarial drug Primaquine diluted in saline solution while control pairs were injected with saline solution. The fumigation treatment was carried out using insecticide solution or water for fumigated and control nests respectively. Brood size was the main factor associated with the abundance of biting midges probably because more nestlings may produce higher quantities of vector attractants. In addition, birds medicated against haemoparasites breeding in non-fumigated nests supported a higher abundance of C. festivipennis than the rest of the groups. Also, we found that the fumigation treatment reduced the abundance of engorged Culicoides in both medicated and control nests, thus indicating a reduction of feeding success produced by the insecticide. These results represent the first evidence for the role of different factors in affecting the Culicoides infracommunity in wild avian nests.
Exploring the anthelmintic properties of Australian native shrubs with respect to their potential role in livestock grazing systems
Authors: KOTZE A. C. , O'GRADY J. , EMMS J. , TOOVEY A. F. , HUGHES S. , JESSOP P. , BENNELL M. , VERCOE P. E. , REVELL D. K.
Published: June 2009

We measuredin vitroanthelmintic activity in extracts from 85 species of Australian native shrub, with a view to identifying species able to provide a degree of worm control in grazing systems. Approximately 40% of the species showed significant activity in inhibiting development ofHaemonchus contortuslarvae. The most active extracts showed IC50values of 60–300 μg/ml. Pre-incubation with polyvinylpolypyrrolidine removed the activity from some extracts, implicating tannins as the bioactive agent, while in other cases the pre-incubation had no effect, indicating the presence of other anthelmintic compounds. Plant reproductive maturity (onset of flowering or fruiting) was associated with increasing anthelmintic activity in some species. Variability was observed between plants of the same species growing in different environments, while variation between individual plants of the same species within a single field suggests the existence of distinct chemotypes. Significant activity against adultH. contortuswormsin vitrowas also demonstrated in a limited number of extracts tested against this life stage. Our study indicates that there is potential for Australian native shrubs to play an anthelmintic role in grazing systems, and highlights some plant biology factors which will need to be considered in order to maximize any anthelmintic effects.
Social science perspectives on schistosomiasis control in Africa: past trends and future directions
Authors: AAGAARD-HANSEN J. , MWANGA J. R. , BRUUN B.
Published: June 2009

New ways of integrating and scaling up control of neglected tropical diseases (including schistosomiasis) are presently underway. In this context consideration of social science perspectives is essential. In this article, we review social science publications of relevance to sustained control of schistosomiasis in Africa including diagnosis and screening, treatment, supply of clean water and improved sanitation, as well as health communication. Studies of community involvement and links between schistosomiasis control programmes and broader health care systems are also explored. Directions for future social science of relevance to sustainable schistosomiasis control are outlined, including ways of ensuring equitable access to health services as well as involvement of endemic communities and local health care systems based on equal partnership.
Genetic growth potential interacts with nutrition on the ability of mice to cope withHeligmosomoides bakeriinfection
Authors: COLTHERD J. C. , BÜNGER L. , KYRIAZAKIS I. , HOUDIJK J. G. M.
Published: June 2009

Artificial selection for improved productivity may reduce an animal's ability to cope with pathogens. Here, we used Roslin mice, uniquely divergently selected for high (ROH) and low (ROL) body weight, to assess interactive effects of differing growth potential and protein nutrition on host resilience and resistance. In a 2×2×6 factorial design, ROH and ROL mice were either sham-infected or infected with 250 L3Heligmosomoides bakeriand fed diets with 30, 80, 130, 180, 230 and 280 g crude protein per kg. The infected ROL-30 treatment resulted in clinical disease and was discontinued. In the remaining ROL mice, infection and feeding treatments did not affect growth but infection reduced weight gain in ROH-30, ROH-80 and ROH-130 mice. Although infection resulted in temporarily reduced food intake (anorexia) in both mouse lines, mean food intake over the whole experiment was reduced in ROH mice only. ROH mice excreted more worm eggs and had higher worm burdens, with relatively fewer female worms, than ROL mice. However, these resistance traits were not sensitive to dietary protein. These results support the view that selection for high growth may reduce the ability to cope with pathogens, and that improved protein nutrition may to some extent ameliorate this penalty.
Impact of temporal changes and host factors on the genetic structure of a population ofOpisthorchis viverrini sensu latoin Khon Kaen Province (Thailand)
Authors: SAIJUNTHA W. , SITHITHAWORN P. , CHILTON N. B. , PETNEY T. N. , KLINBUNGA S. , SATRAWAHA R. , WEBSTER J. P. , ANDREWS R. H.
Published: June 2009

The population genetics of 317 individualOpisthorchis viverrinifrom Khon Kaen Province Thailand, from 4 different years and 4 cyprinid fish species was examined using multilocus enzyme electrophoresis of enolase (Enol), phosphoglucomutase (Pgm) and triose phosphate isomerase (Tpi). Allele and genotype frequencies forEnolandPgmwere consistent irrespective of year or host species. No heterozygote deficiency was detected forEnol. Significant heterozygote deficiencies were detected in 3 of 4 years forPgm. ForTpi, allele frequencies of the most common allele and genotype frequency varied between years and among individuals from different host species. Heterozygote deficiencies forTpiwere detected in 2 years. No significant heterozygous deficiencies were detected amongO. virerrinifrom different fish species in 2005, except atPgmandTpifromPuntioplites protozsron. There was no statistical significance in pairwiseFSTvalues betweenO. viverrinifromCyclocheilichthys armatusin different years or different host species in 2005. Significant departures from Hardy-Weinberg expectations and a high rate of gene flow in a population ofO. viverriniare discussed in terms of self- and cross-fertilisation, natural selection, non-random mating, the Wahlund effect, presence of null alleles, intensity of infection, biology and ecology of their intermediate cyprinid hosts.
Validating justifications in preschool girls' and boys' friendship group talk: implications for linguistic and socio-cognitive development
Authors: KYRATZIS AMY , ROSS TAMARA SHUQUM , KOYMEN S. BAHAR
Published: June 2009

Children are believed to construct their causal theories through talk and interaction, but with the exception of a few studies, little or nothing is known about how young children justify and build theories of the world together with same-age peers through naturally occurring interaction, Children's sensitivity to when a pair or group of interlocutors who interact frequently together feel that a justification is needed, is an index of developing pragmatic competence (Goetz & Shatz, 1999) and may be influenced by interactive goals and gender identity positioning. Studies suggest that salient contexts for justifications for young children are disagreement and control (e.g. Veneziano & Sinclair, 1995) but researchers have been less recognizant of ‘situations in which partners verbally assist in the construction of justifications as a means to maintain contact or create solidarity’ (Goetz & Shatz, 1999: 722) as contexts for justifications. The present study examined the spontaneously produced justification constructions in the naturally occurring free play of five friendship groups of preschool-aged children (aged from 3 ; 6 to 5 ; 4), in terms of the motivating context of the justification, marking of the causal relationship with a connective, and causal theories accessed in the talk. Partner expansion (validating justifications) was a salient motivating context for justifications, especially in the talk of friendship groups of girls, and seemed to privilege greater marking of the causal relationship with a connective and less arbitrary reasoning. One group of girls varied their use of validating justifications depending on the theme of play. Results are discussed in terms of the implications of use of validating justifications for children's causal theory building with peers, linguistic development, and pragmatic development.
Semantic bias in the acquisition of relative clauses in Japanese
Authors: OZEKI HIROMI , SHIRAI YASUHIRO
Published: June 2009

This study analyzes the acquisition of relative clauses in Japanese to determine the semantic and functional characteristics of children's relative clauses in spontaneous speech. Longitudinal data from five Japanese children are analyzed and compared with English data (Diessel & Tomasello, 2000). The results show that the relative clauses produced by Japanese children predominantly have stative/attributive predicates. Additionally, early relative clauses in Japanese are often used to identify a referent that is not present in the context of interaction. These findings contrast with Diessel & Tomasello's (2000) English data, and possible explanations include the input that children are exposed to, which reflects typological characteristics of noun modification in Japanese.
Linking sandwich pairs
Authors: SCHECHTER MARTIN
Published: June 2009

Since the development of the calculus of variations there has been interest in finding critical points of functionals. This was intensified by the fact that for many equations arising in practice, the solutions are critical points. In searching for critical points, there is a distinct advantage if the functionalGis semibounded. In this case one can find a Palais–Smale (PS) sequenceor even a Cerami sequenceThese sequences produce critical points if they have convergent subsequences. However, there is no clear method of finding critical points of functionals which are not semibounded. Linking subsets do provide such a method. They can produce a PS sequence provided they separate the functional. In the present paper we show that there are pairs of subsets that can produce Cerami-like sequences even though they do not separate the functional. All that is required is that the functional be bounded from above on one of the sets and bounded from below on the other, with no relationship needed between the bounds. This provides a distinct advantage in applications. We apply the method to several situations.
Lower bounds for the number of conjugacy classes of finite groups
Authors: KELLER THOMAS MICHAEL
Published: June 2009

In 2000, L. Héthelyi and B. Külshammer proved that if p is a prime number dividing the order of a finite solvable group G, then G has at least $2\sqrt{p-1}$ conjugacy classes. In this paper we show that if p is large, the result remains true for arbitrary finite groups.
Review of Collision Avoidance and Path Planning Methods for Ships in Close Range Encounters
Authors: Tam CheeKuang , Bucknall Richard , Greig Alistair
Published: June 2009

Efficient marine navigation through obstructions is still one of the many problems faced by the mariner. Many accidents can be traced to human error, recently increased traffic densities and the average cruise speed of ships impedes the collision avoidance decision making process further in the sense that decisions have to be made in reduced time. It seems logical that the decision making process be computerised and automated as a step forward to reduce the risk of collision. This article reviews the development of collision avoidance techniques and path planning for ships, particularly when engaged in close range encounters. In addition, previously published works have been categorised and their shortcomings highlighted in order to identify the ‘state of the art’ and issues in close range marine navigation.
Application of Computational Fluid Dynamics Simulations to the Analysis of Bank Effects in Restricted Waters
Authors: Lo D. C. , Su Dong-Taur , Chen Jan-Ming
Published: June 2009

It is well known that vessels operating in the vicinity of a lateral bank experience a significant yaw moment and sway force. This bank effect has a major impact on the manoeuvring properties of the vessel and must therefore be properly understood to ensure the safe passage of the vessel through the restricted waterway. Accordingly, this study performs a series of simulations using commercial FLOW-3D® computational fluid dynamics (CFD) software and the KRISO 3600 TEU container ship model to examine the effects of the vessel speed and distance to bank on the magnitude and time-based variation of the yaw angle and sway force. The results show that for a given vessel speed, the yaw angle and sway force increase as the distance to bank reduces, while for a given distance between the ship and the bank, the yaw angle and sway force increase with an increasing vessel speed. In addition, it is shown that even when a vessel advances at a very low speed, it experiences a significant bank effect when operating in close vicinity to the bank. Overall, the results presented in this study confirm the feasibility of the CFD modelling approach as a means of obtaining detailed insights into the bank effect without the need for time-consuming and expensive ship trials.
Klobuchar-Like Local Model of Quiet Space Weather GPS Ionospheric Delay for Northern Adriatic
Authors: Filjar Renato , Kos Tomislav , Kos Serdjo
Published: June 2009

Ionospheric delay is the major source of satellite positioning system performance degradation. Designers of satellite positioning systems attempt to mitigate the impact of the ionospheric delay by deployment of correction models. For instance, the American GPS utilises a global standard (Klobuchar) model, based on the assumption that the daily distribution of GPS ionospheric delay values follows a biased cosine curve during day-time, while during the night-time the GPS ionospheric delay remains constant. Providing a compromise between computational complexity and accuracy, the Klobuchar model is capable of correcting up to 70% of actual ionospheric delay, mainly during quiet space weather conditions. Unfortunately, it provides a very poor performance during severe space weather, geomagnetic and ionospheric disturbances. In addition, a global approach in Klobuchar model development did not take into account particularities of the local ionospheric conditions that can significantly contribute to the general GPS ionospheric delay. Current research activities worldwide are concentrating on a better understanding of the observed GPS ionospheric delay dynamics and the relation to local ionosphere conditions.

Here we present the results of a study addressing daily GPS ionospheric delay dynamics observed at a Croatian coastal area of the northern Adriatic (position ϕ=45°N, λ=15°E) in the periods of quiet space weather in 2007. Daily sets of actual GPS ionospheric delay values were assumed to be the time series of composite signals, consisting of DC, cosine and residual components, respectively. Separate models have been developed that describe components of actual GPS ionospheric delay in the northern Adriatic for summer and winter, respectively. A special emphasis was given to the statistical description of the residual component of the daily distribution of GPS ionospheric delay, obtained by removing DC (bias) and cosine components from the composite GPS ionospheric delay.

Future work will be focused on further evaluation and validation of a quiet space weather GPS ionospheric delay model for the northern Adriatic, transition to a non-Klobuchar model, and on research in local GPS ionospheric delay dynamics during disturbed and severe space weather conditions.
New Algorithm for Great Elliptic Sailing (GES)
Authors: Pallikaris Athanasios , Latsas George
Published: June 2009

An analytical method and algorithm for great elliptic sailing (GES) calculations is presented. The method solves the complete GES problem calculating not only the great elliptic arc distance, but also other elements of the sailing such as the geodetic coordinates of intermediate points along the great elliptic arc. The proposed formulas provide extremely high accuracies and are straightforward to be exploited immediately in the development of navigational software, without the requirement to use advanced numerical methods. Their validity and effectiveness have been verified with numerical tests and comparisons to extremely accurate geodetic methods for the direct and inverse geodetic problem.
Shore-Based Pilotage: Pilot or Autopilot? Piloting as a Control Problem
Authors: Bruno Karl , Lützhöft Margareta
Published: June 2009

Remote, or shore-based, pilotage is an issue of some interest to the maritime community. When discussed, it is often in the context of new technology that in one way or the other is supposed to enhance piloting and enable ships to be piloted from the shore. This paper takes a different approach and instead looks at piloting as control of a complex system. Such an approach makes it possible to identify a fundamental problem with remote pilotage. The problem, along with possible solutions, is presented and discussed.
A Hidden Markov Model-Based Map-Matching Algorithm for Wheelchair Navigation
Authors: Ren Ming , Karimi Hassan A.
Published: June 2009

Application of map-matching techniques to GPS positions can provide accurate vehicle location information in challenging situations. The Hidden Markov Model (HMM) is a statistical model that is well known for providing solutions to temporal recognition applications such as text and speech recognition. This paper introduces a novel map-matching algorithm based on HMM for GPS-based wheelchair navigation. Given GPS positions, a hidden Markov chain model is established by using both geometric data and the topology of sidewalk segments. The map-matching algorithm employs the Viterbi algorithm to estimate correct sidewalk segments as hidden states in a HMM in order to match GPS trajectory on the corresponding segment sequence. The HMM-based map-matching algorithm was validated on a campus sidewalk network for wheelchair navigation. The results show an improvement in tracking a wheelchair in dense urban conditions both in accuracy and in computational time.
The Controversial Skill of Columbus as a Navigator: An Enduring Historical Enigma
Authors: Peck Douglas T.
Published: June 2009

This study of Columbus' navigation is unique because it was written by an historian who is also a trained and experienced professional global (and ocean) navigator, rather than an academic historian with only superficial knowledge of the science of navigation as practiced by Columbus and other early navigators. The study is also unique in that as an American historian author disagrees with his colleagues in the USA who present the “politically correct” view of Columbus as an unskilled entrepreneur who obtained his limited knowledge of navigation as a crew member or passenger on Portuguese voyages, rather than as one of the most skilled and experienced of the cadre of respected Genoese captains and navigators used by kings throughout Europe to perform their maritime enterprises.
Improved Filter Strategies for Precise Geolocation of Unexploded Ordnance using IMU/GPS Integration
Authors: Lee Jong Ki , Jekeli Christopher
Published: June 2009

Efficient and precise geolocation can be achieved by integrating a ranging system, such as GPS, with inertial sensors in order to bridge short outages, enhance accuracy degradation, and increase the temporal resolution in the ranging system. Optimal integration depends on appropriate filter methods that can accommodate the particular short-term dynamics experienced by platforms, such as UXO ground-based detection systems. The traditional extended Kalman filter was designed to integrate data from a linearized system excited by Gaussian noise. We compared this filter to modern filters that obviate these prerequisites, including the unscented Kalman filter, the particle filter, and adaptive variations thereof, using simulated IMU/ranging systems that follow a typical trajectory with both straight and curved segments. The unscented filter performed significantly better than the extended Kalman filter, particularly over the curved segments, yielding up to 50% improvement in the position accuracy using medium-grade inertial measurement units. Similar improvement was obtained for the unscented particle filter, and its adaptive variant, over the unscented Kalman filter (which performed comparably to the extended Kalman filter) when the statistical distribution of the IMU noise was non-symmetric (i.e., essentially non-Gaussian). While the few-centimetre geolocation accuracy goal for highly dynamic UXO characterization applications remains a challenge if tactical grade IMUs are integrated with a significantly degraded ranging system, using filters appropriate to the inherent nonlinear dynamics and potential non-Gaussian nature of the sensor noise tend to reduce overall errors compared to the traditional filter.
Alcock and Brown
Authors: Hayward Terry
Published: June 2009

This year celebrates the 90th anniversary of the historic first Atlantic crossing by Alcock and Brown in their Vickers aircraft. This paper draws on the log, chart, notes and equipment held in the RAF Museum at Hendon and Sir Arthur Brown's own words to tell the story of the crossing.
When is a VTS not a VTS?
Authors: Hughes Captain Terry
Published: June 2009

This paper traces the birth and formation of Vessel Traffic Services, examines the rapid growth of such schemes worldwide and notes the tendency for mandatory ship reporting systems to be operated from VTS centres. Questions are asked about this tendency and thoughts are provided.
Pupil constriction evoked in vitro by stimulation of the oculomotor nerve in the turtle (Trachemys scripta elegans)
Authors: DEARWORTH JAMES R. , BRENNER J.E. , BLAUM J.F. , LITTLEFIELD T.E. , FINK D.A. , ROMANO J.M. , JONES M.S.
Published: June 2009

The pond turtle (Trachemys scripta elegans) exhibits a notably sluggish pupillary light reflex (PLR), with pupil constriction developing over several minutes following light onset. In the present study, we examined the dynamics of the efferent branch of the reflex in vitro using preparations consisting of either the isolated head or the enucleated eye. Stimulation of the oculomotor nerve (nIII) using 100-Hz current trains resulted in a maximal pupil constriction of 17.4% compared to 27.1% observed in the intact animal in response to light. When current amplitude was systematically increased from 1 to 400 μA, mean response latency decreased from 64 to 45 ms, but this change was not statistically significant. Hill equations fitted to these responses indicated a current threshold of 3.8 μA. Stimulation using single pulses evoked a smaller constriction (3.8%) with response latencies and threshold similar to that obtained using train stimulation. The response evoked by postganglionic stimulation of the ciliary nerve using 100-Hz trains was largely indistinguishable from that of train stimulation of nIII. However, application of single-pulse stimulation postganglionically resulted in smaller pupil constriction at all current levels relative to that of nIII stimulation, suggesting that there is amplification of efferent drive at the ganglion. Time constants for constrictions ranged from 88 to 154 ms with relaxations occurring more slowly at 174–361 ms. These values for timing from in vitro are much faster than the time constant 1.66 min obtained for the light response in the intact animal. The rapid dynamics of pupil constriction observed here suggest that the slow PLR of the turtle observed in vivo is not due to limitations of the efferent pathway. Rather, the sluggish response probably results from photoreceptive mechanisms or central processing.
Exercise capacity reflects ventricular function in patients having the Fontan circulation
Authors: Klimes Katrin , Ovroutski Stanislav , Abdul-Khaliq Hashim , Ewert Peter , Alexi-Meskishvili Vladimir , Kuehne Titus , Gutberlet Matthias , Berger Felix
Published: June 2009

Background

In this study we sought to determine, first, whether maximal exercise capacity reflects ventricular function, and second, whether the age of the patient, and the age of completion of the Fontan circulation, influence ventricular function and exercise performance.

Methods and Results

Cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed in 29 patients at a median time of 6.9 years after completion of the Fontan circulation. We divided the patients into 2 groups, the first 19 having their operation below the age of 18 years, and the second group, of 10 patients, having completion of the Fontan circulation when they were older than 18 years. Parameters for ventricular function and exercise were compared for both groups with controls.

Compared to controls, the younger patients had normal end-diastolic ventricular volumes, but significantly impaired ventricular function, lower maximal work load and consumption of oxygen. The older patients had greater end-diastolic ventricular volumes, and significantly poorer ventricular function than both the younger patients and the controls. Maximal work load and consumption of oxygen were significantly lower in the older patients than in the younger ones and the controls.

Conclusion

Patients with the Fontan circulation have an impaired systolic ventricular function, which correlates with maximal exercise capacity and uptake of oxygen. Those having completion of the Fontan circulation when younger than 18 years had significantly better ventricular function and exercise performance than those who had completion of the Fontan circulation at an older age. An early creation of the Fontan circulation may preserve cardiac function and exercise capacity.
Democratic dilemmas in EU multilevel governance: untangling the Gordian knot
Authors: Hurrelmann Achim , DeBardeleben Joan
Published: June 2009

This article discusses what implications the European Union’s (EU’s) multilevel structure has for its democratic legitimacy. It identifies three channels of democratic input in the EU – the European Parliament, national democratic processes influencing the Council of Ministers, and civil society participation in consultation procedures of the European Commission – and assesses them on the basis of a comprehensive set of criteria. The evaluation shows that the democratization of the EU faces three interlinked dilemmas. Most fundamentally, there is an incongruence in territorial scope between the issues requiring democratic control (increasingly European if not global) and the imagined communities necessary for the functioning of democratic procedures (primarily national). This ‘congruence dilemma’ intensifies contradictions between participation and deliberation, as well as between effectiveness and accountability in EU decision-making. Grand reforms that would solve these dilemmas once and for all are unlikely to be successful, but changes in the interplay of the three democratic channels – such as the disentanglement of political competencies, the formalization of inter-channel conciliation procedures, and the introduction of directly democratic mechanisms – promise to mitigate their negative effects.
Domesticating discourses: European law, English judges, and political institutions
Authors: Jupille Joseph , Caporaso James A.
Published: June 2009

Political science research on Europeanization has focused too little on the domestic legal-constitutional implications of European legal integration. We address this relative neglect, identifying two models of the impact of European law on domestic judicial discourses and testing them against evidence on the invocation of three EU law concepts within English courts. Contrary to a statist model, which expects judicial discourses to correspond closely with direct importations of European law through the preliminary reference procedure, we find stronger support for an indigenization model in which courts gradually domesticate previously alien concepts. These domesticating discourses offer new insights into domestic political and constitutional orders in the context of European and international legalization.
The Multilevel Parliamentary Field: a framework for theorizing representative democracy in the EU
Authors: Crum Ben , Fossum John E.
Published: June 2009

This article introduces the concept of the ‘Multilevel Parliamentary Field’ as a means for analysing the structure of democratic representation in the European Union (EU). This concept is warranted for several reasons. First, the multilevel configuration that makes up the EU contains two channels of democratic representation: one directly through the European Parliament, the other indirectly through the national parliaments and governments. These two channels are likely to persist side by side; hence, both the European and the national parliaments can claim to represent ‘the people’ in EU decision-making. Second, this structure of representation is in many respects without precedent; it does not fit established concepts of democratic representation derived from the nation-state or from international relations, such as a federal two-channel system or a parliamentary network. Third, the representative bodies in the EU are interlinked, also across levels. Up until now, no proper conceptual apparatus has been devised that can capture the distinctive traits of this EU multilevel representative system, and help to assess its democratic quality. The concept of the Multilevel Parliamentary Field fills both these tasks. It serves as a heuristic device to integrate the empirical analysis of the different forms of democratic representation in the EU’s multilevel system, and it provides new angles for analysing the democratic challenges that this system faces.
Legitimacy in the multilevel European polity
Authors: Scharpf Fritz W.
Published: June 2009

To be at the same time effective and liberal, governments must normally be able to count on voluntary compliance – which, in turn, depends on the support of socially shared legitimacy beliefs. In Western constitutional democracies, such beliefs are derived from the distinct, but coexistent traditions of ‘republican’ and ‘liberal’ political philosophy. Judged by these criteria, the European Union – when considered by itself – appears as a thoroughly liberal polity which, however, lacks all republican credentials. But this view (which seems to structure the debates about the ‘European democratic deficit’) ignores the multilevel nature of the European polity, where the compliance of citizens is requested, and needs to be legitimated, by member states, whereas the Union appears as a ‘government of governments’, which is entirely dependent on the voluntary compliance of its member states. What matters primarily, therefore, is the compliance–legitimacy relationship between the Union and its member states – which, however, is normatively constrained by the basic compliance–legitimacy relationship between member governments and their constituents. Given the high consensus requirements of European legislation, member governments could, and should, be able to assume political responsibility for European policies in which they had a voice, and to justify them in ‘communicative discourses’ in the national public space. That is not necessarily so for ‘non-political’ policy choices imposed by the European Court of Justice (ECJ). By enforcing its ‘liberal’ programme of liberalization and deregulation, the ECJ may presently be undermining the ‘republican’ bases of member-state legitimacy. Where that is the case, open non-compliance is a present danger, and political controls of judicial legislation may be called for.
Putting European political science back together again
Authors: Keating Michael
Published: June 2009

Political science is the product of modernity and the nation-state. A dominant tradition within it has striven for a positivistic and universal form of understanding, based on the individual actor. Developments in recent years have questioned our understanding of modernity, universalism, science, and the nation-state. Political science has responded in two ways: by reinforcing the positivist approach, or by adopting various forms of intepretivism. This has created an artificial division within the discipline. Political scientists can overcome this artificial divide by looking outside the discipline. There are promising developments in this direction but these are inhibited by trying to confine them within the dominant positivist mode. They have also responded by borrowing from neighbouring disciplines, but in doing so, they have too often appropriated concepts in simplified form or coined empty concepts. They need to take neighbouring disciplines more seriously and work across disciplinary boundaries. A pluralistic approach is possible, which neither seeks a grand synthesis of all the social sciences, nor sees them as independent and self-standing, but which encourages cross-fertilization and combinations of approaches. The existence of distinct European national and disciplinary traditions, far from being an obstacle to the development of the discipline, gives European political scientists an advantage.
Atmospheric Ionization Module Osnabrück (AIMOS): A 3‐D model to determine atmospheric ionization by energetic charged particles from different populations
Authors: Wissing J. M. , Kallenrode M.‐B.
Published: June 2009

We present a 3‐D numerical model of atmospheric ionization due to precipitating particles with high spatial resolution. The Atmospheric Ionization Model Osnabrück (AIMOS) consists of two parts: a GEANT4‐based Monte Carlo simulation and a sorting algorithm to assign observations from two polar‐orbiting satellites to horizontal precipitation cells, depending on geomagnetic activity. The main results are as follows: (1) the sorting algorithm and thus the 3‐D mapping of particle fluxes works reasonably well; (2) ionization rates are in good agreement with the ones from earlier models; (3) during quiet times, the major contribution to ionospheric ionization is from electrons both in the polar cap (solar electrons) as well as in the auroral oval (magnetospheric electrons) with the ionization in the auroral oval exceeding that in the polar cap; (4) during solar particle events the dominant effect in the polar cap in the stratosphere and mesosphere is from solar protons although solar electrons can contribute up to 30% to the ionization; (5) during strong shocks following a solar particle event, in the auroral oval magnetospheric electrons and protons lead to ionization rates of up to some 10% of the ones of solar particles; and (6) independent of particle source and precipitation site, in general, ionization by electrons is more important in the thermosphere.
Seasonal variability of the Equatorial Undercurrent at 10°W as inferred from recent in situ observations
Authors: Kolodziejczyk N. , Bourlès B. , Marin F. , Grelet J. , Chuchla R.
Published: June 2009

Eighteen cross‐equatorial shipboard current profiling sections along 10°W with conductivity‐temperature‐depth measurements taken between 1997 and 2007 are used to analyze the mean meridional structure and the seasonal variability of the Equatorial Undercurrent (EUC) at 10°W. Our analysis suggests a seasonal cycle for the EUC transport at 10°W, with a well‐defined annual harmonic and some indication of a semiannual component, with a first maximum in January and a second stronger maximum from June to September. The mean EUC transport at 10°W is estimated to be 12.1 Sv and, compared to earlier estimates farther in the west, at 35°W (20.9 Sv) and 26°W (13.8 Sv). The eastward flow transport exhibits a strong variability at 10°W (with a total range of transports from 7.1 Sv to more than 31.7 Sv). The seasonal amplitude of the eastward flow variability is ±8.9 Sv, from a minimum of 8.2 Sv in November to 25.9 Sv in August. The eastward flows within the thermocline are divided in two parts: a permanent part within the σθ = 24.5–26.5 isopycnal layer, with a semiannual cycle, known as the EUC, and a nonpermanent part in the deep thermocline (beneath σθ = 26.5 isopycnal), associated with a strong eastward transport (up to 15 Sv) during the boreal summer, that is not observed during the rest of the year. The current at the equator in the deep thermocline is even westward during boreal fall. The disappearance of the salinity core of the EUC during the boreal summer, associated with the upwelling of the hydrological structure at 10°W, reveals that the saline subtropical waters carried by the EUC within the thermocline no longer flow into the Gulf of Guinea during the boreal summer. Our data also show the presence of the South Equatorial Undercurrent (SEUC) at 10°W in the Gulf of Guinea with a strong latitudinal and depth variability throughout the year. The mean SEUC at 10°W is centered near 5°S and is farther south than observed at 35°W and 26°W, suggesting its poleward shift from west to east.
Overview of the magnetic properties experiments on the Mars Exploration Rovers
Authors: Madsen M. B. , Goetz W. , Bertelsen P. , Binau C. S. , Folkmann F. , Gunnlaugsson H. P. , í Hjøllum J. , Hviid S. F. , Jensen J. , Kinch K. M. , Leer K. , Madsen D. E. , Merrison J. , Olsen M. , Arneson H. M. , Bell J. F. , Gellert R. , Herkenhoff K. E. , Johnson J. R. , Johnson M. J. , Klingelhöfer G. , McCartney E. , Ming D. W. , Morris R. V. , Proton J. B. , Rodionov D. , Sims M. , Squyres S. W. , Wdowiak T. , Yen A. S.
Published: June 2009

The Mars Exploration Rovers have accumulated airborne dust on different types of permanent magnets. Images of these magnets document the dynamics of dust capture and removal over time. The strongly magnetic subset of airborne dust appears dark brown to black in Panoramic Camera (Pancam) images, while the weakly magnetic one is bright red. Images returned by the Microscopic Imager reveal the formation of magnetic chains diagnostic of magnetite‐rich grains with substantial magnetization (>8 Am2 kg−1). On the basis of Mössbauer spectra the dust contains magnetite, olivine, pyroxene, and nanophase oxides in varying proportions, depending on wind regime and landing site. The dust contains a larger amount of ferric iron (Fe3+/Fetot ∼ 0.6) than rocks in the Gusev plains (∼0.1–0.2) or average Gusev soil (∼0.3). Alpha Particle X‐Ray Spectrometer data of the dust show that some of the iron in magnetite is substituted by titanium and chromium. The good correlation of the amount of calcium and sulfur in the dust may be caused by the presence of a calcium sulfate related phase. The overall mineralogical composition points to a basaltic origin of the airborne dust, although some alteration has taken place as indicated by the large degree of oxidation.