bluuebunny/crossref_metadata_2025 huggingface dataset:
An illustrative example of refactoring object‐oriented source code with aspect‐oriented mechanisms
Authors: Monteiro Miguel P. , Fernandes João M.
Published: August 2007

This paper describes a refactoring process that transforms a Java source code base into a functionally equivalent AspectJ source code base. The process illustrates the use of a collection of refactorings for aspect‐oriented source code, covering the extraction of scattered implementation elements to aspects, the internal reorganization of the extracted aspects and the extraction of commonalities to super‐aspects. Copyright © 2007 John Wiley & Sons, Ltd.
A survey on approaches to gridification
Authors: Mateos Cristian , Zunino Alejandro , Campo Marcelo
Published: August 2007

The Grid shows itself as a globally distributed computing environment, in which hardware and software resources are virtualized to transparently provide applications with vast capabilities. Just like the electrical power grid, the Grid aims at offering a powerful yet easy‐to‐use computing infrastructure to which applications can be easily ‘plugged’ and efficiently executed. Unfortunately, it is still very difficult to Grid‐enable applications, since current tools force users to take into account many details when adapting applications to run on the Grid. In this paper, we survey some of the recent efforts in providing tools for easy gridification of applications and propose several taxonomies to identify approaches followed in the materialization of such tools. We conclude this paper by describing common features among the proposed approaches, and by pointing out open issues and future directions in the research and development of gridification methods. Copyright © 2007 John Wiley & Sons, Ltd.
An agent‐based perspective to handover management in 4G networks
Authors: Zafeiris Vassilis E. , Giakoumakis E. A.
Published: August 2007

In 3G or earlier generation networks handovers are usually initiated and decided by the base station, on the basis of measurements of RSS or SNR received by the terminal, cell congestion, terminal speed etc. In 4G, due to the diversity of available radio access services, additional factors, for example user profile, application requirements, and terminal device capabilities, need also to be taken into account. We propose an agent‐based architecture that determines the timing and target network for handovers in a 4G network setting. The capabilities of the architecture are provided as a value‐added service on top of network operators' wireless access infrastructure. Network selection spans both wireless access and core routing services and is performed by user agents executing in the network side. In order to deal with trust issues we study the integration of the regulatory authority in the architecture. A performance study of the architecture's impact on handover latency is provided through a simulation system. Copyright © 2007 John Wiley & Sons, Ltd.
Maternal substance use and HIV status: Adolescent risk and resilience
Authors: Leonard Noelle R. , Gwadz Marya Viorst , Cleland Charles M. , Vekaria Pooja C. , Ferns Bill
Published: August 2007

We examined the risk and protective factors and mental health problems of 105 low SES, urban adolescents whose mothers were coping with alcohol abuse and other drug problems. Approximately half of the mothers were also HIV‐infected. As hypothesized, there were few differences between adolescents of HIV‐infected and HIV‐uninfected mothers in background characteristics, mental health issues and current substance use risk behaviors. In addition to maternal substance abuse, youth in both groups experienced similar risk factors including early foster care placement and high levels of maltreatment. Current patterns of emerging risk behaviors were evident among youth in both groups as well as signs of resiliency including high levels of school attendance. These results underscore the importance of interventions for youth of substance abusing mothers, particularly those living in urban poverty.
Synergistic interaction between meloxicam and aminoguanidine in formalin‐induced nociception in mice
Authors: Dudhgaonkar Shailesh P. , Tandan Surendra K. , Kumar Dinesh , Arunadevi R. , Prakash V. Ravi
Published: August 2007

Objectives:The objective of this study was to examine the nature of interaction between cyclooxygenase‐2 inhibitor meloxicam and inducible nitric oxide synthase inhibitor aminoguanidine in formalin‐induced nociception in mice and the possible therapeutic advantage.

Methods:Antinociceptive effect of meloxicam (1, 3, 10 and 30mg/kg, oral) and aminoguanidine (10, 30, 100 and 300mg/kg, oral) and their combinations was examined in formalin‐induced paw licking model in mice. Analysis of variance and isobolographic method were employed to identify the nature of antinociceptive interaction.

Results:Higher doses of meloxicam (10 and 30mg/kg) and aminoguanidine (100 and 300mg/kg) produced significant reduction in paw licking time (antinociceptive) in late phase of formalin‐induced nociception. Combination of sub‐threshold dose of meloxicam (3mg/kg) with increasing doses of aminoguanidine (10, 30, 100 and 300mg/kg) resulted in synergistic antinociceptive effect. Similarly, co‐administration of sub‐threshold dose of aminoguanidine (30mg/kg) with increasing doses of meloxicam (1, 3, 10 and 30mg/kg) produced significant reduction in formalin‐induced paw licking behaviour. The experimental ED50for combination with their confidence limits are below the confidence interval of theoretical line of additive interaction, suggesting synergistic nature of interaction between meloxicam and aminoguanidine in isobolographic analysis.

Conclusion:Co‐administration of meloxicam and aminoguanidine showed synergistic antinociceptive effect which might possibly reduce gastrointestinal toxicity associated with the use of meloxicam.
Dental otalgia
Authors: Kim D S , Cheang P , Dover S , Drake-Lee A B
Published: August 2007

Background:

Secondary or referred otalgia can represent a diagnostic challenge to the otolaryngologist. Collectively, dental disorders are the most common causes of secondary otalgia presenting to the ENT clinic, and may account for up to 50 per cent of referred otalgia. Temporomandibular joint dysfunction syndrome represents the most common dental cause of referred otalgia. Decay and pulpal inflammation of posterior teeth can also frequently present as otalgia. The common embryological developmental origin of both oral and dental structures and the ear is responsible for their overlapping sensory nerve supplies, and this explains referred otalgia secondary to dental and temporomandibular joint disorders. These disorders can be easily overlooked, resulting in unnecessary and costly investigations.

Aims:

This review aims to give a succinct overview of common dental causes of otalgia, and to provide ENT clinicians with guidelines for performing a rapid and simple dental and temporomandibular joint examination, which will reliably diagnose or exclude dental otalgia.
Editorial
Authors: THOMPSON JUNE
Published: August 2007

If some readers are surprised to receive a copy of ReCALL at this early stage in the year, let me remind you that we are now moving from two to three issues a year, for publication in January, May and September instead of May and November. The changeover has proved rather difficult, in terms of allowing time for authors to make revisions in the light of reviewers’ comments, which is why this issue is rather late.

In this issue, as well as regular papers from Dermot Campbell, Fenfang Hwu and Elke Stracke, we have included two papers from the EUROCALL 2006 conference in Granada. Melor Md Yunus discusses Malaysian ESL Teachers’ Use of ICT in Their Classrooms, whilst Petter Karlström and colleagues explore Tool mediation in focus-on-form activities. Having received 39 conference paper submissions, so far 13 have been rejected (but some of these have been advised to submit a version of their paper to the EUROCALL Review) and the remainder are at various stages in the process of bringing them to publication. Tony Harris, organiser of the Granada conference, will have more to say about conference submissions in the next issue of ReCALL, where the bulk of the selected papers will be published.
The need for a speech corpus
Authors: CAMPBELL DERMOT F. , MCDONNELL CIARAN , MEINARDI MARTI , RICHARDSON BUNNY
Published: August 2007

This paper outlines the ongoing construction of a speech corpus for use by applied linguists and advanced EFL/ESL students. In the
first part, sections 1–4, the need for improvements in the teaching of listening skills and pronunciation practice for EFL/ESL students is noted.
It is argued that the use of authentic native-to-native speech is imperative in the teaching/learning process so as to promote social inclusion. The
arguments for authentic language learning material and the use of a speech corpus are contextualised within the literature, based mainly on the work of
Swan, Brown and McCarthy. The second part, section 5, addresses features of native speech flow which cause difficulties for EFL/ESL students (Brown,
Cauldwell) and establishes the need for improvements in the teaching of listening skills. Examples are given of reduced forms characteristic of
relaxed native speech, and how these can be made accessible for study using the Dublin Institute of Technology’s slow-down technology, which
gives students more time to study native speech features, without tonal distortion. The final part, sections 6–8, introduces a novel Speech
Corpus being developed at DIT. It shows the limits of traditional corpora and outlines the general requirements of a Speech Corpus. This tool –
which will satisfy the needs of teachers, learners and researchers – will link digitally recorded, natural, native-to-native speech so that each transcript
segment will give access to its associated sound file. Users will be able to locate desired speech strings, play, compare and contrast them – and slow them
down for more detailed study.
Learners’ strategies with a grammar application: the influence of language ability and personality preferences
Authors: HWU FENFANG
Published: August 2007

This case study investigated the ways pre-major and pre-minor students of Spanish interacted with a grammar application from four perspectives. Firstly, using the computer’s tracking ability to collect learners’ behaviors, the study set out to uncover the different ways learners approached the application. Secondly, the study assessed the influence of two learner variables on learning behaviors: language abilities determined by a placement test and personality preferences measured by Jung-Myers-Briggs-Typology based approach. Thirdly, the study assessed whether the frequency of various behaviors resulted in different knowledge increases. Finally, the study categorized the uncovered behaviors into the learning strategies covered in the Strategy Inventory for Language Learning (SILL) (Oxford 1990). The study concludes with implications for software improvement, as well as with indications of likely directions for future research.
Didactic patterns for electronic materials in the teaching of interculturalism through literature: the experience of the research group LEETHi
Authors: LÓPEZ-VARELA AZCÁRATE ASUNCIÓN
Published: August 2007

This paper is a descriptive summary of a research project on blended learning in the Faculty of Arts at the University Complutense Madrid. The project was conducted as action research in 2002-06 by the research group LEETHi. LEETHi’s projects focus on the teaching of literature from an intercultural perspective while helping to develop new media competence. The project also addresses – among other objectives – the intercultural potential of literary tests used in second language acquisition where their practical applications include the development and use of digital material for the study of European literatures with the integration of multiple languages and perspectives. A central issue is the potential of blended learning (i.e. the integration of e-learning and contact learning) and the development of autonomy and communication between students and instructor. The online scenario focuses on the performance of tasks following sociocultural and constructivist theories and concepts borrowed from research on multimodality.
Tool mediation in Focus on Form activities: case studies in a grammar-exploring environment
Authors: KARLSTRÖM PETTER , CERRATTO-PARGMAN TERESA , LINDSTRÖM HENRIK , KNUTSSON OLA
Published: August 2007

We present two case studies of two different pedagogical tasks in a Computer Assisted
Language Learning environment called Grim. The main design principle in Grim is to support ‘Focus on Form’ in second language pedagogy.
Grim contains several language technology-based features for exploring linguistic forms (static, rule-based and statistical), intended to be used
while writing. Our question is, in what ways does Grim support Focus on Form in actual classroom use. We have explored this question within
sociocultural theory, emphasizing tool mediation and how tools shape the learner’s activity. The first case concerns a text-reconstruction
exercise in which students worked in a pair within the Grim environment. The second case was conducted with another group of students, who engaged in
collaborative revision of texts, written in advance by one of the students, in student pairs. In both studies, students were instructed and encouraged
to use the different features of Grim. Data was collected by recording dialogue during the sessions with Grim. Our results show how learners put the
features of Grim into use in their writing tasks. In some instances, the program
was used creatively, in combination with external tools such as the
users’ own dictionaries, knowledge of other languages, or teachers. In other instances, we note that Grim was used for error correction, rather
than as a language resource. The learners’ activities are thus transformed by their use of the program, from the tasks of revision and text-reconstruction
into error correction. The application shapes the activity, in conjunction with the pedagogical tasks. We argue for studying the activities of students with
CALL tools, in order to find out in detail how tasks and technology concur in use and what view on language and pedagogy they mediate.
FipsOrtho: A spell checker for learners of French
Authors: L’HAIRE SÉBASTIEN
Published: August 2007

This paper presents FipsOrtho, a spell checker targeted at learners of French, and a corpus of learners’ errors which has been gathered to test the system and to get a sample of specific language learners’ errors. Spell checkers are a standard feature of many software products, however they are not designed for specific language learners’ errors. After a brief review of the state of the art, we describe the system’s architecture and interfaces. Then we describe our error typology and detail the techniques used to retrieve words and to order proposals appropriately: alphacode, phoneticization, ad-hoc, capitalization, apostrophe, and word separation error methods. Proposals are sorted by a score depending on the method(s) used to retrieve them, on the expected lexical category, gender, number and person, and on the string proximity with the unknown word. Then the test results are presented: a list of individual words containing errors was submitted to the alphacode and phoneticization methods; a corpus of authentic learners’ errors was gathered and analyzed. Finally we conclude the paper with some limitations of the system and ideas for future research.
Post-dispersal embryo growth and acquisition of desiccation tolerance inAnemone nemorosaL. seeds
Authors: Ali Natasha , Probert Robin , Hay Fiona , Davies Hannah , Stuppy Wolfgang
Published: August 2007

A UK seed conservation collection ofAnemone nemorosaL. seeds held at the Millennium Seed Bank (MSB) showed low viability in its first post-storage test. Because achenes ofA. nemorosaare naturally dispersed when they are green, we tested the hypothesis that seeds may not be fully desiccation tolerant and storable at the time of natural dispersal, and that a post-harvest treatment could increase the proportion of desiccation-tolerant seeds. Achenes harvested at the point of natural dispersal in late May in 2003 and 2004 were either placed immediately on 1% water agar at 20°C (‘laboratory’ treatment), or placed in nylon sachets and buried in leaf litter among plants growing in the wild (‘field’ treatment). Samples were withdrawn at intervals over a period of 168 d and tested for desiccation tolerance (drying to 0.059 g H2O (g DW)− 1) and longevity (controlled ageing at 60% relative humidity and 45°C). An initial increase, followed by a decline, in the proportion of seeds surviving desiccation and in the longevity of both laboratory- and field-treated samples coincided with the development of embryos from globular to heart- and then torpedo-shaped. Developmental arrest was not required for the acquisition of desiccation tolerance, and continued growth and development of the embryo resulted in a loss of desiccation tolerance, similar to that seen in orthodox seeds upon radicle emergence. Furthermore, whileA. nemorosaseeds, like many from theRanunculaceaefamily, might be described as having morphological or morphophysiological dormancy, this lack of developmental arrest does not fit with the usual concept of dormancy. The implications of these results for the classification systems of seed-storage behaviour and dormancy, and for the long-term conservation of seeds ofA. nemorosa, are discussed.
Germination rates ofSolanum sisymbriifolium: temperature response models, effects of temperature fluctuations and soil water potential
Authors: Timmermans B.G.H. , Vos J. , van Nieuwburg J. , Stomph T.J. , van der Putten P.E.L.
Published: August 2007

Four temperature response models were compared describing the emergence rate ofSolanum sisymbriifolium(L.) over a broad range of suboptimal temperatures and at different soil water potentials. In the laboratory, the effects were tested on germination rates at constant (9.1–21.8°C) and diurnally fluctuating temperatures at different soil water potentials. Linear, Q10, expolinear and quadratic models were fitted to the data on rate of emergence against temperature. For model validation, field emergence was monitored in 11 sowings conducted in 2001–2004. Emergence rate increased with temperature and was relatively high at soil water potentials in the range of − 0.21 MPa to − 2.6 × 10− 3 MPa, but was almost zero at − 0.96 MPa and − 1.8 × 10− 3 MPa. Diurnal temperature fluctuations did not have a differing influence on germination rates or final germination percentages compared with constant temperatures. The expolinear and the quadratic models were most accurate in explaining variation of laboratory data, especially at temperatures close to the minimum germination temperature ofS. sisymbriifolium. These two models had root mean square errors for predicting field emergence rates (5.9 to 38.4 d) of 0.81 and 0.87 d, respectively, and were considered more appropriate to predict the time to 50% germination for crops grown in conditions near their ‘base temperature’ than the widely used linear temperature (thermal time) models. The Gompertz function was fitted to percentage germination versus the time-accumulated germination rate (using the expolinear function to describe the rate–temperature relation). This combined model adequately predicted the temporal pattern of emergence in the field.
Sorting out theLeMANs: endo-β-mannanase genes and their encoded proteins in tomato
Authors: Gong Xuemei , Derek Bewley J.
Published: August 2007

Endo-β-mannanase (EC 3.2.1.78) is involved in the hydrolysis of mannan-type polysaccharides that are present in plant cell walls, especially those of the seed endosperm. The genes encoding the endo-β-mannanases have been studied extensively in tomato (Solanum lycopersicum), and five genes (LeMAN1,LeMAN2,LeMAN3,LeMAN4andLeMAN5) and/or their products have been isolated and characterized.LeMAN1,LeMAN2andLeMAN3are expressed in tomato seeds,LeMAN4in the fruit andLeMAN5in the flower.LeMAN5andLeMAN2are now considered to be the same gene, and the former is re-designated asLeMAN2*. Transcripts ofLeMANs1, 2and3are detected only in the endosperm of tomato seeds, and their synthesis is promoted by gibberellic acid.LeMAN4, in the fruit, occurs asLeMAN4aandLeMAN4igenes that encode an active or inactive form of endo-β-mannanase, respectively.LeMAN1–4 enzymes encoded by these genes share 80% similarity in amino acid sequence. In tomato, the leucine amino acid present near to the C-terminus of the endo-β-mannanase is the most important for achieving full activity of the enzyme.
A Randomized Controlled Trial of Cognitive Behavioural Therapy as an Adjunct to Pharmacotherapy in Primary Care Based Patients with Treatment Resistant Depression: A Pilot Study
Authors: Wiles Nicola J , Hollinghurst Sandra , Mason Victoria , Musa Meyrem , Burt Victoria , Hyde Julia , Jerrom Bill , Lewis Glyn , Kessler David
Published: August 2007

No randomized controlled trials (RCTs) have been conducted of cognitive behavioural therapy (CBT) for depressed patients who have not responded to antidepressants, yet CBT is often reserved for this group. We conducted a pilot study for a pragmatic RCT of the clinical effectiveness of CBT as an adjunct to pharmacotherapy in primary care based patients with treatment resistant depression (TRD). Patients on antidepressants for at least 6 weeks were mailed a study invitation by their GP. Those who consented to contact were mailed a questionnaire. TRD was defined as compliance with medication (self-report) and Beck Depression Inventory (BDI) ≥ 15. Those who met ICD-10 depression criteria were eligible for randomization and followed after 4 months. Of 440 patients mailed, 65% responded and 72% consented to contact. Ninety-four percent completed the questionnaire and 82 patients (42%) had TRD. Thirty were subsequently identified as ineligible and 10 did not participate further. Twenty-six of the remaining 42 patients met ICD-10 depression criteria and 25 agreed to being randomized. Twenty-three patients completed the 4-month follow-up questionnaire. Recruitment into a RCT to examine the effectiveness of CBT as an adjunct to pharmacotherapy in primary care based patients with TRD appears feasible and should now be conducted.
Cognitive Behaviour Therapy with Refugees and Asylum Seekers Experiencing Traumatic Stress Symptoms
Authors: Grey Nick , Young Kerry
Published: August 2007

This paper describes the nature of the difficulties faced by asylum seekers and refugees who present with traumatic stress symptoms and uses existing cognitive models to better understand theoretical issues in these cases. The focus is on those people for whom traumatic stress symptoms are their main problem/pre-occupation. It is acknowledged that these people may only form a small proportion of those who have experienced such events. This paper does not focus on the important multicultural issues integral to this work. A possible clinical pathway is presented, including the role of exposure/reliving, and how it may be adapted where necessary for people who have experienced multiple traumatic events, often of prolonged duration. Discussion of possible psychosocial understandings of torture and mass violence may be important in this work. A case example is presented that demonstrates how this clinical pathway might unfold in practice.
Empowered Consumers and Telephone Hotlines
Authors: MacKinnon Christina
Published: August 2007

Today health-care budgets are rapidly being cut and services streamlined. Volunteers and nonprofit agencies have been commissioned to take on part of the burden. Currently they are expanding and reorganizing their services to meet the new demand. Telephone crisis lines, in particular, have the potential to take on a large share of consumer needs—they are always available and turn no one away. Unfortunately, crisis lines have their own set of problems. Although the bulk of work is performed by volunteers and represents a minimum of expense, the clientele is varied, the workload unpredictable. Staff at the line need to balance the needs of their regular callers with crisis calls and their volunteer needs by establishing comprehensive policies. This article looks at just a few of the challenges these lines face, and attempts to analyze the options, keeping the rights of modern consumers in mind.
Suicides in Hong Kong and Australia
Authors: Yip Paul SF
Published: August 2007

Although the suicide rate for both Hong Kong and Australia was about 12 per 100,000 in 1994, the age- and gender-specific rates, methods of suicide, and time trends vary greatly for these two places. This paper explores the possible social, economic, and cultural background to explain this discrepancy. We used the official suicide death statistics of Hong Kong and Australia for the period 1984-1994. We calculated age-standardized suicide rates in order to take into account the differences in the age composition between the two countries and years. We employed a log-linear (Poisson) model to detect the age- and gender-specific trends, and to determine whether there were specific age or gender groups whose suicide behavior had changed significantly between 1984 and 1994. Hong Kong experienced a slight increase in suicide rate for both genders in the years 1984-1994, whereas Australia experienced a cubic trend for both genders during the same period and a rise in suicide rate in recent years. The suicide rate in Hong Kong increased with age, with a sharp increase (nearly four times the average) among the group aged 75 or over. A relatively low gender ratio (male:female) was also observed in Hong Kong, whereas in Australia there was not much difference in suicide rates among all age groups, though the suicide rate of the group aged 75 or over was 1.2 times the average. The gender ratio in Australia was higher, and the male suicide rate was four times higher than that of females. The Hong Kong suicide rate in females was twice that of Australia, whereas the Hong Kong male suicide rate was about half that of Australia. Jumping and hanging were the most common methods of suicide in Hong Kong, accounting for more than 80% of all suicide deaths. Poisoning (including gas poisoning) was the most common method used in Australia, with firearms being more common among young males. Australia had a higher years of potential life lost (YPLL) than Hong Kong because of the higher suicide rate among young males (aged 15-24). The high suicide rate among the elderly in Hong Kong raises the possibility that medical and social support to the elderly could be enhanced. The high female suicide rate in Hong Kong could be related to workload, responsibility, and expectations. The high suicide rate in Australia among males aged 15-24 was disturbing. Availability of the suicide methods is certainly one explanation for the difference in suicide methods used in Hong Kong and Australia.
Euthanasia and the Terminally Ill: Can the Civil Killing of Others Be Eroded?
Authors: Kelleher † Michael J. , Payne Anne , Corcoran Paul , Chambers Derek
Published: August 2007

The present paper assesses attitudes towards the ending of life among a sample of 100 terminally ill hospice patients. Such a sample best provides an insight into the demand for euthanasia in this most extreme of circumstances. Of the completed interviews (64), 43 patients were fully aware of the implications of their condition; 35 expressed a definite opinion regarding euthanasia, 22 of whom favored the individual's right to choose the timing of death. Only 6 of these 22 were fully competent at the time of the interview and were not suffering from any depressive disorder. The implications of these results point to the need to consider the prevalence of depression, anxiety, and related disorders among those who seek an end to life. A failure to do so is likely to affect legislation worldwide and, in turn, civilization itself.
Toward earthquake early warning in northern California
Authors: Wurman Gilead , Allen Richard M. , Lombard Peter
Published: August 2007

Earthquake early warning systems are an approach to earthquake hazard mitigation which takes advantage of the rapid availability of earthquake information to quantify the hazard associated with an earthquake and issue a prediction of impending ground motion prior to its arrival in populated or otherwise sensitive areas. One such method, Earthquake Alarm Systems (ElarmS) has been under development in southern California and, more recently, in northern California. Event magnitude is estimated using the peak amplitude and the maximum predominant period of the initial P wave. ElarmS incorporates ground motion prediction equations and algorithms from ShakeMap for prediction of ground motions in advance of the S wave arrival. The first peak ground motion estimates are available 1 s after the first P wave trigger, and are updated each second thereafter for the duration of the event. The ElarmS methodology has been calibrated using 43 events ranging in size from ML 3.0 to Mw 7.1 that occurred in northern California since 2001. We present the results of this calibration, as well as the first implementation of ElarmS in an automated, noninteractive setting and the results of 8 months of noninteractive operation in northern California. Between February and September 2006, ElarmS successfully processed 75 events between Md 2.86 to Mw 5.0. We find that the ElarmS methodology processed these events reliably and accurately in the noninteractive setting. The median warning time afforded by this method is 49 s at the major population centers of the Bay Area. For these events the magnitude estimate is within an average of 0.5 units of the network‐derived magnitude, and the ground motion prediction from ElarmS is within an average of 0.1 units of the observed modified Mercalli intensity.
Albedo of summer snow on sea ice, Ross Sea, Antarctica
Authors: Zhou Xiaobing , Li Shusun , Morris Kim , Jeffries Martin O.
Published: August 2007

Surface all‐wave albedo and physical parameters (grain radius, mass density, surface temperature, and stratification) of an austral summer snow cover on sea ice were measured in the Ross Sea during January‐February 1999. It was observed that (1) from north to south the snow surface temperature decreases, albedo increases, snow mass density decreases, snow composite grain radius decreases, and number density of composite grains increases; (2) the size of the clusters of snow grains (i.e., melt clusters and well‐bonded chains of grains), rather than the size of the individual snow grains, is the dominant parameter controlling albedo (the smaller the snow composite grain radius and the larger the number density are, the higher the albedo is); and (3) in determining the snow albedo, grain size dominates over the number density and the upper layers dominate over the lower layers. A comparison of the statistical relation between albedo and the averaged grain size shows that statistical significance is independent of the selection of the grain size averaging method. Suggestions for snow albedo parameterization are made.
Origin of C2–C5dicarboxylic acids in the European atmosphere inferred from year‐round aerosol study conducted at a west‐east transect
Authors: Legrand M. , Preunkert S. , Oliveira T. , Pio C. A. , Hammer S. , Gelencsér A. , Kasper‐Giebl A. , Laj P.
Published: August 2007

An atmospheric study of C2–C5dicarboxylic acids was conducted over two years at seven sites located from the Azores to eastern continental European sites. The lowest concentrations of total C2–C5diacids are observed at the Azores (Portugal) and at 4360 m elevation in the Alps (∼50 ng m−3), and the highest (400 ng m−3) are observed at the rural K‐puszta site (Hungary). Quasi‐absent at surface sites, the seasonal cycle of total diacids is characterized by a pronounced summer maximum at elevated sites, the highest summer level (510 ng m−3) being observed at the forested mountain site of Schauinsland (Germany). Whatever site and season, oxalic acid is always the most abundant diacid with a relative abundance higher than 60%. The climatology of C2–C5diacids in Europe is discussed versus environmental conditions at sites (marine/continental, rural/forested, boundary layer/free troposphere, and winter/summer). Observations are used to discuss the possible sources of C2–C5diacids, with special emphasis on their primary versus secondary and natural versus anthropogenic origin. At surface sites in winter, fast secondary productions in wood burning plumes in addition to secondary production from volatile organic carbon (VOC) species emitted by vehicles seem to be important contributors. In summer the impact of anthropogenic sources is weakened and biogenic emissions from vegetation (unsaturated fatty acids, isoprene, oxygenated VOCs, and eventually monoterpenes) likely represent major precursors of diacids. At the Azores, diacids are not only related to long‐range transport from continents but also to marine biogenic emissions from phytoplankton, particularly in summer.
Organic amine biomarker detection in the Yungay region of the Atacama Desert with the Urey instrument
Authors: Skelley Alison M. , Aubrey Andrew D. , Willis Peter A. , Amashukeli Xenia , Ehrenfreund Pascale , Bada Jeffrey L. , Grunthaner Frank J. , Mathies Richard A.
Published: August 2007

The Urey in situ organic compound analysis instrument, consisting of a subcritical water extractor (SCWE) and a portable microchip capillary electrophoresis instrument called the Mars Organic Analyzer (MOA), was field tested in the Atacama Desert, Chile, in June 2005. Soil samples from the most arid Yungay region were collected, biomarkers were extracted by the SCWE, and organic amine composition and amino acid chirality analysis was performed by the MOA. Samples collected from the top 1 cm of duracrust soil but shielded from the ambient environment by rocks were compared to the exposed duracrust. The shielded duracrust yielded amines and amino acids ranging from 50 to 100 ppb, while amino acid signals from the exposed duracrust were below blank levels. Samples from buried gypsum deposits located directly above a water flow channel contained amino acids ranging from 13 to 90 ppb. Chiral analysis revealed D/L ratios of 0.39 ± 0.08 and 0.34 ± 0.07 for alanine/serine and 0.78 ± 0.06 for aspartic acid, indicating significant racemization of biologically produced amino acids. On the basis of the D/L ratios, we estimate sample ages ranging from 103 to 105 years. These results demonstrate the successful field testing of the Urey instrument, as well as the detection of biomarkers from past terrestrial life in one of the most arid and Mars‐like regions on Earth.
Origin and fate of phosphorus in the Seine watershed (France): Agricultural and hydrographic P budgets
Authors: Némery Julien , Garnier Josette
Published: August 2007

Phosphorus (P) sources (point and diffuse) in the human‐impacted Seine basin (64,840 km2) were evaluated for the year 2000. An agricultural P budget showed that fertilizers represented 59% (20–25 kgP ha−1) of P inputs to the soils. A P surplus (2.5 kg P ha−1 y−1) contributed to P enrichment of the agricultural soils whose stocks amounted to 1800–5000 kgP ha−1. A hydrographic P budget showed that runoff (0.39–0.51 kgP ha−1) dominated the diffuse sources. These losses represented a very low percentage (0.01%) of the P stocks in soils and contributed to 19–25% of the total P inputs to the drainage network. Point sources remained the main source of P (75–81%), particularly in the downstream urbanized zone. Phosphorus retention in the river drainage network accounted for 9–15% of the total P inputs, indicating that it must not be ignored in large river P budget calculations. The Seine basin exported 8000 tP y−1 (44% as particulate P) to its estuary. The annual mean particulate P in suspended sediment at the outlet (2.9 gP kg−1) was fourfold greater than in headwaters and in rural zones. The similar increase of the particulate inorganic P/particulate organic P ratio in suspended sediment along the river continuum clearly indicated the increasing pressure of point sources. The close relation between P content of suspended sediment during the high‐flow period and the P content of agricultural soils resulted in proposing a novel method to calculate the PP losses from runoff.
A parametric study of atmospheric superrotation on Venus‐like planets: Effects of oblique angle of planetary rotation axis
Authors: Yamamoto Masaru , Takahashi Masaaki
Published: August 2007

Parametric experiments of superrotation on slowly rotating planets, such as Venus, were conducted. The oblique angle of the planetary rotation axis is one of the most important parameters in the dynamics of the superrotation. New relationships are found for the maximum mean zonal flow, meridional flow, and equator‐pole temperature difference. For low obliquity, the dynamic state alternates between weak and strong superrotations with a period of about 10000 days in the phase space, and small fluctuations of about 1000 days are also seen. Fully‐developed superrotation is maintained by meridional circulation and waves in the case of a slightly oblique angle. However, it is not formed in the case of a highly oblique angle, since the vertical transport of angular momentum due to meridional circulation is ineffective at the solstices. The superrotational wind becomes larger with decreasing obliquity.
Evaluation of the Moderate Resolution Imaging Spectroradiometer aerosol products at two Aerosol Robotic Network stations in China
Authors: Mi Wen , Li Zhanqing , Xia Xiangao , Holben Brent , Levy Robert , Zhao Fengsheng , Chen Hongbin , Cribb Maureen
Published: August 2007

Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products have been used to address aerosol climatic issues in many parts of the world, but their quality has yet to be determined over China. This paper presents a thorough evaluation of aerosol optical depth (AOD) data retrieved from MODIS collections 4 (C004) and 5 (C005) at two AERONET sites in northern and southeastern China. Established under the aegis of the East Asian Study of Tropospheric Aerosols: An International Regional Experiment (EAST‐AIRE) project, the two sites, Xianghe and Taihu, have distinct ecosystems and climate regimes, resulting in differences in retrieval performance. At the rural northeastern site (Xianghe), MODIS C004 retrievals generally overestimate AOD at 550 nm during clean days, with the largest errors occurring during winter. In the warm and humid regions of southeastern China (Taihu), MODIS C004 retrievals overestimate AOD throughout the year. The systematic error at Xianghe is primarily due to the fixed surface reflectance ratio, while as the error at Taihu is mainly caused by the choice of the single scattering albedo (SSA) for the fine model aerosols. Both problems are alleviated considerably in the C005. The comparisons between C005 retrievals and AERONET data show much higher correlation coefficient, lower offset and a slope closer to unity. Also, the variability of AOD retrieval among neighboring pixels is reduced by several factors. The strong overestimation problem at small AOD values was fixed by using dynamic reflectance ratios that vary with the vegetation index and scattering angle. However, significant uncertainties remain because of the use of highly simplified aerosol models.
Evolution of Co-operation When the Strategies are Hidden: The Human Mating Game
Authors: Watve Milind , Damle Anuja , Ganguly Bratati , Kale Anagha
Published: August 2007

Defection is frequently seen in co-operative systems [1-3]. Game theoretical solutions to stabilize cooperation rely on reciprocity and reputation in iterated games[4-5]. One of the basic requirements for reciprocity or reputation building is that the strategies of players and the resulting payoffs should be open at the end of every interaction. For games in which the strategies and payoffs remain hidden, these stabilizing factors are unlikely to work. We examine the evolution of cooperation for hidden-strategy games using human mating game as an example. Here faithful parenting can be considered as cooperation and extra-pair mating (EPM) or cuckoldry as defection. Cuckoldry may get exposed only occasionally and the genetic benefits of cuckoldry also remain hidden from the players. Along with mate guarding, social policing is enabled in humans by language and gossiping. However, social policing can be invaded by second order free riders. We suggest that opportunistic blackmailing, which is unique to hidden strategy games can act as a keystone strategy in stabilizing co-operation. This can counteract free riding and stabilize policing. A game theoretical model results into a rock - paper – scissor (R-P-S) like situation with no evolutionary stable strategy (ESS). Simulations result into a stable or stably oscillating polymorphism. Obligate monogamy is an essential trait in the co-existence. In a gender difference model too, polymorphism is seen in both genders but with different traits predominating in the two genders. The model explains intra-gender, inter-gender as well as cross cultural variability in mating strategies in humans.
Dynamics of pulsed expansion of polyatomic gas cloud: Internal-translational energy transfer contribution
Authors: Morozov A. A.
Published: August 2007

Polyatomic gas cloud expansion under pulsed laser evaporation is studied on the basis of one-dimensional direct Monte Carlo simulation. The effect of rotational-translational (RT) and vibrational-translational (VT) energy transfer on dynamics of the cloud expansion is considered. Efficiency of VT energy transfer dependence on the amount of evaporated matter is discussed. To analyze VT energy transfer impact, the number of collisions per molecule during the expansion is calculated. The data are generally in good agreement with available analytical and numerical predictions. Dependencies of the effective number of vibrational degrees of freedom on the number of vibrationally inelastic collisions are obtained and generalized. The importance of the consideration of energy transfer from the internal degrees of freedom to the translational ones is illustrated by an example of pulsed laser evaporation of polytetrafluoroethylene (PTFE). Based on the obtained regularities, analysis of experimental data on pulsed laser evaporation of aniline is performed. The calculated aniline vibrational temperature correlates well with the experimentally measured one.
Nonperturbative theory for the optical response to strong light of the light harvesting complex II of plants: Saturation of the fluorescence quantum yield
Authors: Richter M. , Renger Th. , Renger G. , Knorr A.
Published: August 2007

Recent progress in resolution of the structure of the light harvesting complex II provides the basis for theoretical predictions on nonlinear optical properties from microscopic calculations. An approach to absorption and fluorescence is presented within the framework of Bloch equations using a correlation expansion of relevant many particle interactions. The equations derived within the framework of this theory are applied to describe fluorescence saturation phenomena. The experimentally observed decrease of the normalized fluorescence quantum yield from 1 to 0.0001 upon increasing the intensity of laser pulse excitation at 645nm by five orders of magnitude [R Schödel et al., Biophys. J. 71, 3370 (1996)] is explained by Pauli blocking effects of optical excitation and excitation energy transfer.
Mixing properties of a stably stratified parallel shear layer
Authors: Monti Paolo , Querzoli Giorgio , Cenedese Antonio , Piccinini Simonetta
Published: August 2007

The results of a laboratory investigation on turbulent mixing of mass and momentum associated with the collapse of Kelvin-Helmholtz waves which develop in a stably stratified parallel shear layer with O(103) Schmidt number are presented. The waves were generated in a stratified, tilting tank using a denser fluid underlying a lighter fluid with a velocity shear between the layers. Detailed velocity and density measurements were conducted simultaneously using particle tracking velocimetry and laser-induced fluorescence techniques. Estimation of the efficiency of mixing, the ratio between the diffusive flux of density responsible for mixing, to the turbulent kinetic energy dissipation rate, suggest it is independent of the initial values of the Reynolds and the bulk Richardson numbers. The measurements of the eddy diffusivities of mass and momentum showed a reasonable agreement with other laboratory-based predictions of turbulent mixing and observational data in atmospheric stably stratified flows.
The elementary energy transfer between the two-point velocity mean and difference
Authors: Germano M.
Published: August 2007

In this paper, the elementary energy transfer between the two-point average of a velocity field and the two-point difference has been examined. The equations related to the two-point quantities are derived from the Navier-Stokes equations applied to incompressible flows. Some interesting aspects of this simple transfer of energy are discussed both from the point of view of the filtered equations associated with the two-point velocity average and from the point of view of the properties of the structure functions associated with the two-point velocity difference. A new inertial relation valid for homogeneous flows is finally presented.
Extreme ionization of Xe clusters driven by ultraintense laser fields
Authors: Heidenreich Andreas , Last Isidore , Jortner Joshua
Published: August 2007

We applied theoretical models and molecular dynamics simulations to explore extreme multielectron ionization in Xen clusters (n=2–2171, initial cluster radius R0=2.16–31.0Å) driven by ultraintense infrared Gaussian laser fields (peak intensity IM=1015–1020Wcm−2, temporal pulse length τ=10–100fs, and frequency ν=0.35fs−1). Cluster compound ionization was described by three processes of inner ionization, nanoplasma formation, and outer ionization. Inner ionization gives rise to high ionization levels (with the formation of {Xeq+}n with q=2–36), which are amenable to experimental observation. The cluster size and laser intensity dependence of the inner ionization levels are induced by a superposition of barrier suppression ionization (BSI) and electron impact ionization (EII). The BSI was induced by a composite field involving the laser field and an inner field of the ions and electrons, which manifests ignition enhancement and screening retardation effects. EII was treated using experimental cross sections, with a proper account of sequential impact ionization. At the highest intensities (IM=1018–1020Wcm−2) inner ionization is dominated by BSI. At lower intensities (IM=1015–1016Wcm−2), where the nanoplasma is persistent, the EII contribution to the inner ionization yield is substantial. It increases with increasing the cluster size, exerts a marked effect on the increase of the {Xeq+}n ionization level, is most pronounced in the cluster center, and manifests a marked increase with increasing the pulse length (i.e., becoming the dominant ionization channel (56%) for Xe2171 at τ=100fs). The EII yield and the ionization level enhancement decrease with increasing the laser intensity. The pulse length dependence of the EII yield at IM=1015–1016Wcm−2 establishes an ultraintense laser pulse length control mechanism of extreme ionization products.
Formation and characterization of carbon nanowires
Authors: Kumar Amit , Avasthi D. K. , Tripathi A. , Filip L. D. , Carey J. D. , Pivin J. C.
Published: August 2007

This article reports on the formation and electronic characteristics of conducting carbon nanowires produced by swift heavy ion irradiation of a fullerene thin film. This study shows that it is possible to create arrays of carbon nanowires, which are perfectly parallel to each other and perpendicular to the substrate. As-deposited fullerene films exhibit poor field emission characteristics with breakdown fields as high as 51 V/μm, whereas low dose ion irradiated fullerene film produces a threshold field as low as 9 V/μm. The present approach of making conducting carbon nanowires by ion irradiation for potential field emitters and large area applications is also discussed.