bluuebunny/crossref_metadata_2025 huggingface dataset:
From Celestial Letters to 'Copylore' and 'Screenlore'
Authors: Le Quellec Jean-Loïc
Published: October 2010

Summary: The origins of chain letters, which are now circulated for ludic, humanitarian or profit motives, can be found in age-old religious traditions. This study of the genre shows how these letters became gradually secularized and identifies contemporary forms using such modern methods as fax machines, photocopiers and electronic mail. Thus the ancient 'celestial letters', which were still very much alive in the sixteenth century, became letters sent with the blessing of Saint Anthony, or of mere bishops and parish priests. As the letters became commonplace they also came to he seen as either a miraculous cure or a clever way to make money. With further secularization, wholly ludic chain letters appeared, and then bogus advertising photocopies claiming that recipients have won a fabulous prize - a 'gift from heaven'.
Dopo ze beep. Some observations about the uses of the answering machine
Authors: Mercier Pierre-Alain
Published: October 2010

Summary: The personal answering machine has become part of our daily lives, almost imperceptibly, Unlike other recent innovations, such as mobile telephones, the Internet, and, in France, the Minitel, it has not been the subject of much research, press coverage, advertising or apocalyptic prophecies. Its 'career' may be compared to that of the audio cassette: it offered a marginal improvement, or perhaps just a new type of packaging, that made it easier to use tried and tested technology. Magnetic recording - the 'minicassette', as it was called then - has nonetheless been an indisputable success worldwide, and its supposedly significant impact on leisure, education, cultural identity and communication are difficult to assess accurately.
From Telecommunication to Traffic Distribution
Authors: Gille Laurent
Published: October 2010

Summary: Telecommunications have undergone profound technological, economic and regulatory changes over the past fifteen years. In particular, the widening range of services provided and the proliferation and interconnection of networks have increasingly dissociated subscribers from traffic on a network. The network is less and less a closed sphere linking subscribers whose traffic it "produces". Networks, and specifically télédistribution, mobile and data transmission networks, carry traffic that is no longer generated by their subscribers alone. The network economy is thus becoming increasingly similar to the distribution economy. The massive introduction of intelligent service - which in many respects resembles intelligent distribution and is increasingly characteristic of service providers' added value - is reflected in a mutation in the way financial markets value telecommunications businesses.
Outsourcing: A transaction cost theory approach
Authors: Quélin Bertrand
Published: October 2010

Summary: In this article, outsourcing is defined as the transfer of all or part of the existing information and communication systems (ICS) of a firm to a third party. The argument is based on the central model of transaction cost theory. Traditionally, this model concerns the make-or-buy choice. A firm that decides to outsource its ICS has already made a substantial investment in the system over several years. The article therefore develops an original analysis to help answer the following question: on what terms can a firm transfer ownership rights in highly specific hardware and software, and establish a long-term relationship with the service provider? Finally, the article proposes a generalization and an in- depth reflection on the organizational choices and governance structures to adopt when outsourcing.
Various levels of context analysis in the ergonomic study of cooperative work
Authors: Karsenty Laurent , Pavard Bernard
Published: October 2010

Summary: This article proposes an examination of the different levels of intervention of the notion of context in the ergonomie analysis of work, and methodology for taking them into account, particularly in cooperative work. We successively discuss the perceptive, cognitive, communicational, organisational and cultural contexts which determine and give meaning to the activity of human operators. Each level of context is discussed from a theoretical point of view, and illustrated by case studies. We then propose a methodology for identifying the different determining contextual aspects in a work situation. The main principle in which this methodology is grounded is the analysis of activity. We conclude by proposing guidelines to facilitate the process ofcontextualisation in work. These proposals are illustrated by concrete examples of assistance in the taking into account of context.
Strange Grew Up With Me: Sentimentality and masculinity in readers of superhero comics
Authors: Maigret Éric
Published: October 2010

Summary: This study concerns the consumption of superhero comics in the USA and in France. Drawing on a series of interviews and letters published in magazines over the past three decades, the article shows that, for a considerable part of its readership, this medium represents more than the transmission of a traditional masculinity; it is a means of learning a new and complex identity. The author concludes that the learning of gender identities cannot be seen as a univocal process of inculcation of predetermined roles.
Creation of value on the Internet
Authors: Gensollen Michel
Published: October 2010

Where will the value come from on the Internet? How can money be made on a network where almost everything is free? This article puts forward some ideas. In the short term, e-commerce will be able to finance commercial web sites, but these sites provide only a small proportion of the information accessible on the web. Free sites, in so far as they provide a place where consumers and producers can exchange the information required to design new products and services, are a key component of the Internet. The Internet will also help firms to change their structure in order to accommodate a faster pace of innovation. Internet Protocol applications should help to update individual skills and bring them together into a coherent system of knowledge and behaviour. When finally the information economy obscures the distinction between work and leisure, the Internet will create value either by organizing the control of intellectual property rights on information or by facilitating convergence of information producers and consumers.
Internet or the ideal scientific community
Authors: Flichy Patrice
Published: October 2010

Summary: The Internet is the result of an imagined technological construction in a particular social environment: academic computer science departments. This article considers the intentions and socio-technological choices of the initial designers of the Internet era. It focuses on the definition of the concept of network computing, the setting up of the network and its uses, the creation of a single world network and finally hypertext projects and tools for accessing information. The earliest Internet model built in this framework has remained an unavoidable reference for all 'Internants' to this day.
RESEARCH ON LOAD CAPACITY OF CONCRETE FILLED COLUMNS WITH BATTENED STEEL SECTIONS
Authors: Szmigiera Elzbieta , Zoltowski Wojciech , Siennicki Miroslaw
Published: October 2010

The paper presents experimental and numerical results for selected built‐up steel columns filled with concrete. The laboratory tests were accompanied by numerical analysis carried out using general purpose, finite element program ABAQUS. Based on heretofore research presented in this paper, one may assumes that the application of concrete filled columns with battened steel sections is economically very profitable. For columns filled with concrete strength class C20/25 the increase of load bearing capacity was 42% and for elements filled with concrete strength class C50/60 ‐ above 100%. The application of the shorter distance between battens allowed to obtain additional increase of ultimate load (for concrete C20/25 ‐ about 8%). The numerical analysis also confirmed the increase of the load capacity for the columns. The best correlation between numerical and experimental results was obtained for the assumed eccentricity of 1 mm. Moreover the higher rigidity of those members in relation to steel columns is not connected with significant increase of the cost. The study was conducted as a part of the research project nr 4TO7E01528, founded by the Polish Ministry of Science and Higher Education. Santrauka Straipsnyje pristatomi plieniniu kolonu, užpildytu dvieju tipu betonu, eksperimentiniai ir skaitiniai tyrimu rezultatai. La‐boratoriniai bandymai ir skaitine analize buvo atliekami naudojant bendrosios paskirties baigtiniu elementu programa ABAQUS. Remiantis šiame straipsnyje pateiktais tyrimo rezultatais, galima daryti prielaida, kad kolonos iš standžiu plieniniu skerspjūviu, užpildytu betonu, yra labai ekonomiškos. Kolonos, užpildytos C20/25 betonu, laikomoji galia padidejo 42 %, o elemento, užpildyto C50/60, ‐ daugiau negu 100 %. Kai atstumas tarp sutvirtintu vietu trumpesnis, galima padidinti didžiausiaja apkrova (naudojant betono klase C20/25 ‐ apie 8 %). Skaitine analize patvirtino padidejusia kolonu laikomaja galia. Geriausia koreliacija tarp eksperimentiniu ir skaitiniu rezultatu buvo gauta esant tariamam 1 mm ekscentricitetui. Be to, didesnis šiu elementu standumas, palyginti su plieninemis kolonomis, nera susijes su išlaidu padidejimu. Šis mokslinis tyrimas buvo mokslinio projekto Nr. 4TO7E01528, kuri inicijavo Lenkijos studiju ir aukštojo mokslo ministerija, dalis.
SIMULATION BASED COMPLEX ENERGY ASSESSMENT OF OFFICE BUILDING FENESTRATION
Authors: Motuzienė Violeta , Juodis Egidijus Saulius
Published: October 2010

The number of office buildings with highly fenestrated facades is currently increasing in Lithuania and neighboring countries. Highly fenestrated facades reduce energy consumption for lighting and simultaneously increase energy consumption for heating, cooling, air conveying and may cause thermal and visual discomfort. Pursuing to reduce negative effects of the highly glazed facade, special glasses are frequently used. However, such windows usually increase demand for lighting energy. Therefore, when making early decisions about glazing the building, it is important to have a complex evaluation of energy demand related to the specific case. The paper presents the results of analysis made using energy simulation tools. The obtained results have shown that when shading is not applied, the north is the most energy efficient orientation to glazing for an air conditioned office building in cool climate zones like Lithuania. The most energy efficient window‐to‐wall ratios (WWR) for the south, east and west oriented façade are 20%, whereas for the north it makes 20–40%. However, such WWR values do not satisfy standard requirements for day lighting. Santrauka Pastaraisiais metais Lietuvoje ir kaimyninese šalyse daugeja administracines paskirties pastatu, kuriu dauguma išoriniu atitvaru yra skaidrios. Didesnis istiklinimo plotas lemia mažesnius energijos poreikius apšvietimui, tačiau didina šildymo ir vesinimo sistemu energijos poreikius, sukelia šilumini bei vizualini diskomforta. Neigiamai dideliu skaidriu atitvaru itakai sumažinti naudojami tamsinti ir kitu specialiu charakteristiku stiklai, tačiau tai savo ruožtu didina energijos poreiki apšvietimui. Todel, priimant sprendimus del pastato istiklinimo, svarbu prieš tai kompleksiškai išnagrineti konkretaus sprendimo itaka pastato energijos poreikiams. Straipsnyje pateikiama modeliuojant gautu rezultatu analize. Rezultatai parode, kad vesaus klimato šalyse, kurioms priklauso ir Lietuva, kondicionuojamu administraciniu pastatu fasadu, kai nenaudojamos apsaugos nuo saules priemones, energiškai efektyviausias istiklinimas yra i šiaures puse. Energiškai efektyviausias santykinis fasado istiklinimo plotas pietines, rytines ir vakarines orientacijos fasadams yra 20 %, o šiaurines ‐ 20–40 %. Tačiau tokie istiklinimo plotai neatitinka norminiu natūralaus apšvietimo reikalavimu.
STATIC ANALYSIS AND SIMPLIFIED DESIGN OF SUSPENSION BRIDGES HAVING VARIOUS RIGIDITY OF CABLES
Authors: Grigorjeva Tatjana , Juozapaitis Algirdas , Kamaitis Zenonas
Published: October 2010

Increased deformability can be considered as the basic disadvantage of suspension bridges. One of the ways to increase the rigidity of a suspension bridge is to transfer a part of stiffening girder rigidity to a suspension main cable. To give the suspension bridge more stable appearance, the authors propose to use the cables of varying bending stiffness. The main cables can be made of standard section shapes or have a composite section. The object of this work was to study a method for analyzing and determining the internal forces in the main cables and stiffening girder under static loading to provide recommendations for designing suspension bridges with stiffened cables. Simple formulas are presented for determining displacements, internal forces and stresses in the main cable and stiffening girder. Finite element modeling was performed. The final part of the paper discusses design procedures for such suspension systems. An example of a pedestrian suspension bridge is appended. Santrauka Esminis kabamuju tiltu trūkumas ‐ didelis ju deformatyvumas. Deformatyvumui sumažinti autoriai siūlo dali standumo sijos lenkiamojo standžio perduoti kabamajam lynui. Baigtinio lenkiamojo standumo lynai gali būti daromi iš standartiniu valcuotuju profiliuočiu arba sudetinio skerspjūvio. Šio darbo tikslas ‐ pateikti supaprastinta metodika kabamojo tilto standaus lyno ir standumo sijos elgsenos analizei atlikti bei rekomendacijas tokiems statiškai apkrautiems tiltams projektuoti. Pateiktos paprastos formules lyno ir sijos poslinkiams, iražoms ir itempiams apskaičiuoti. Atliktas kabamosios tilto siste‐mos modeliavimas baigtiniais elementais. Aptartos tokiu kabamuju tiltu projektavimo procedūros. Pateiktas pesčiuju via‐duko kabamuju konstrukciju projektavimo pavyzdys.
Four new species of fan worms (Polychaeta: Sabellidae) from worldwide localities
Authors: Tovar-Hernández María Ana , Dean Harlan
Published: October 2010

Four new species of soft-bottom sabellid polychaetes are described and illustrated. Branchiomma costaricensis n. sp. is described from 31 m depth off Isla del Coco, Costa Rica; Dialychone arabica n. sp. from 105 m depth in the Arabian Sea; Dialychone blakei n. sp. from 487 m depth off Louisiana in the Gulf of México and Paradialychone harrisae n. sp. from 30 m depth in southern California. Branchiomma costaricensis n. sp. is characterized by having microstylodes with the median pair 1.5 times longer than neighbouring pairs, thoracic uncini with two rows of teeth above the main fang, an unspotted body and large interramal eyespots. Dialychone arabica n. sp. has the anterior peristomial ring lobe exposed beyond the collar and a pre-pygidial depression occupying eight segments. In D. blakei n. sp., the anterior peristomial ring lobe is not exposed beyond the collar, the pre-pygidial depression occupies the last four segments and the posterior segments possess thin elongate, narrowly hooded chaetae. Paradialychone harrisae n. sp. differs from the other species of the genus in having the anterior peristomial ring lobe bilobed and exposed beyond the collar, a rectangular ventral collar shield and paleate chaetae with a long mucro.
Mobile Information System, How to Build with Case Study
Authors: Al-Sayyed Rizik M. H. , Manaseer S. , Rababeh O.
Published: October 2010

In a distributed computing environment, comprising mobile computers and wireless networks, users change their locations frequently while still expecting â??acceptable
Motivation, Psychology and Language Effect on Mobile Learning in Universiti Sains Malaysia
Authors: Ismail Issham , M.Idrus Rozhan , Gunasegaran Thenmolli
Published: October 2010

The aim of this study was to examine the motivation, psychology and language effect on Mobile learning in the School of Distance Education, Universiti Sains Malaysia, Penang. Mobile learning or m-learning is a new learning phenomenon in the open and distance learning environments. Moving from stationary to mobile learning allows informal collaboration and interaction between learners. Therefore, there is a necessity to revise peopleâ??s psychological factors, process and mechanisms that underlie M-learning so that the practice can move from technology-centred implementation to human-centred effective learning processes. The Statistical Package for Social Science (SPSS) Version 12.0 and Rasch Model Analysis was used to measure these items. The 5-point Likert scale questionnaires (12 items) being sent to 105 distance education students from four courses including Bachelor of Science, Bachelor of Arts, Bachelor of Social Science and Bachelor of Management which was distributed in tutorial sessions during the annual residential intensive course in the main campus of the Universiti Sains Malaysia by their respective course managers. The finding shows that a positive response from the learners as they feel happy to use this additional learning tools (mobile learning). Learnerâ??s feel supported and motivated to use the mobile application with the usability of simple language.
Building an e-Commerce Infrastructure in Jordan: Challenges and Requirements
Authors: Al-Shboul Muhannad Anwar , Alsmadi Izzat Mahmoud
Published: October 2010

Many countries around the world are trying to build and enhance their internet infrastructure and utilize services related to the Internet such as e-Commerce, information connectivity, accessibility, etc. However, studies indicated that network and hardware requirements are not always the major barrier for progressing in these goals. In some cases, cultural, legal or environmental factor may dominate the type of barriers for the expansion of internet related service in many countries around the world. This paper presents challenges and requirements for the enhancement of e-Commerce services in particular for Jordan.
Acclimation Improves Short-Term Survival of Hatchery Lahontan Cutthroat Trout in Water From Saline, Alkaline Walker Lake, Nevada
Authors: Bigelow John P. , Rauw Wendy M. , Gomez-Raya Luis
Published: October 2010

We investigated the effectiveness of two acclimation protocols for 8-month-old Lahontan cutthroat trout Oncorhynchus clarkii henshawi, reared at Lahontan National Fish Hatchery in terms of survival during a week-long challenge in water from saline, alkaline Walker Lake, Nevada. Fish were acclimated for 0 (control), 3, and 8 d by increasing the ratio of lake water to hatchery water. For the 3-d acclimation treatment, 50% of the tank water was replaced with lake water each day. For the 8-d treatment, 33% of the water was replaced with lake water on the first through fourth day of acclimation. Survival during acclimation (i.e., prior to the challenge) was lowest for fish acclimated 3 d. Median survival time during the lake water challenge was 8 h for unacclimated fish, and 8 and 12 h for fish surviving the 3- and 8-d acclimation treatments, respectively. No fish survived the entire week-long challenge. Compared with no acclimation, 3- and 8-d acclimation decreased the hazard of mortality during the challenge. Increased fork length also reduced the hazard of death. Our results indicate acceptable survival rates cannot be achieved for subyearling, hatchery-reared Lahontan cutthroat trout stocked in Walker Lake without acclimation or with the acclimation methods employed in this study. Our results indicate that the acclimation method might be improved by the use of longer fish, longer acclimation, and better control of water temperature, ammonia concentration, and alkalinity.
Coconut Breeding in Indonesia
Authors: Liyanage D V , Mankey T
Published: October 2010

Not availableDOI: http://dx.doi.org/10.4038/cocos.v4i0.978COCOS 1986 Vol.4 No.1 1-10
Studies on the Use of Radioisotopes for the Control of Red Palm Weevil, Rhynchophorus ferruginues F. by the Sterile Insect Technique
Authors: Kloft WJ , Kloft ES , Kanagaratnam P , Pinto JLJG
Published: October 2010

No abstractDOI: http://dx.doi.org/10.4038/cocos.v4i0.979COCOS Vol.4 No.2, 11-17
Some Observations on the Position of the Soft Eye in Cocos nucifera
Authors: Wickramaratne MRT , Padmasiri M H L
Published: October 2010

No abstractDOI: http://dx.doi.org/10.4038/cocos.v4i0.982Cocos 1986 vol.4 no.1, 35-37
Soybean-Coconut Intercropping
Authors: LIYANAGE M. DE S. , MARTIN M. P. L. D.
Published: October 2010

doi: 10.4038/cocos.v5i0.2047COCOS 1987 Vol.5 28-31
Competitive Effects of Weeds and Beneficial Effects of Mulching on Coconut Seedlings
Authors: REMISON S. U. , MGBEZE G.
Published: October 2010

Dwarf coconut seedlings were raised in polybags under four mulching treatments(no mulch, coconut husk, oil palm bunch refuse and grass) and two weeding regimes(designated Wo and Wl) in the nursery. Weeding was done once every month in Wlplots whilst Wo plots were left unweeded.Weed competition reduced the growth of coconut seedlings a great deal and theunweeded and unmulched plants were not vigorous enough for transplanting. Weedsreduced dry matter yield of leaves, stem and roots in unmulched plots by 61, 46 and 44%respectively. Mulching was beneficial and reduced competitive effects of weeds. Mulchingincreased plant height, girth and dry matter yield. At harvest, leaves formed thegreatest proportion of the dry matter; the mean being 171.6 g compared with 20.8 and43.2 g for stem and roots respectively. Soil temperatures were only moderately reducedby mulching. Coconut husk suppressed weeds the most but oil palm bunch refuseincreased K content of soil more than any other mulch material.doi: 10.4038/cocos.v5i0.2055COCOS 1987 Vol.5 No.1 19-27
Overview of DNA Repair in Trypanosoma cruzi, Trypanosoma brucei, and Leishmania major
Authors: Passos-Silva Danielle Gomes , Rajão Matheus Andrade , Nascimento de Aguiar Pedro Henrique , Vieira-da-Rocha João Pedro , Machado Carlos Renato , Furtado Carolina
Published: October 2010

A wide variety of DNA lesions arise due to environmental agents, normal cellular metabolism, or intrinsic weaknesses in the chemical bonds of DNA. Diverse cellular mechanisms have evolved to maintain genome stability, including mechanisms to repair damaged DNA, to avoid the incorporation of modified nucleotides, and to tolerate lesions (translesion synthesis). Studies of the mechanisms related to DNA metabolism in trypanosomatids have been very limited. Together with recent experimental studies, the genome sequencing of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, three related pathogens with different life cycles and disease pathology, has revealed interesting features of the DNA repair mechanism in these protozoan parasites, which will be reviewed here.
Biological Characteristics and Medical Treatment of Breast Cancer in Young Women—A Featured Population: Results from the NORA Study
Authors: Pronzato P. , Mustacchi G. , De Matteis A. , Di Costanzo F. , Rulli E. , Floriani I. , Cazzaniga M. E.
Published: October 2010

Background. The present paper described the biological characteristics and clinical behavior of young women in the cohort NORA studyPatients and Methods. From 2000–2002, patients () were enrolled at 77 Italian hospitals. Women aged years () were stratified into age groups (, 36–40, 41–45, and 46–50 years). The relationship between age and patient characteristics, cancer presentation, and treatment was analyzed.Results. Younger women more frequently had tumors with ER/PgR-negative(; ), HER2 amplification (; ), and high () Ki67 labelling index (; ). Positive nodal status, large tumors, and elevated Ki67 all associated with the choice for chemotherapy followed by endocrine therapy in hormone receptor-positive patients (). At univariate analysis, ER-ve status, chemotherapy and age resulted as the only statistically significant variables (, , and versus , , resp.). At multivariate analysis, after adjustment for significant clinical and pathological factors, age remains a significant prognostic variable (, ).Conclusion. This cohort study suggests that ageper sèis an important prognostic factor. The restricted role of early diagnosis and the aggressive behavior of cancer in this population make necessary the application of targeted medical strategies crucial.
Retrieval of tropospheric NO2 using the MAX-DOAS method combined with relative intensity measurements for aerosol correction
Authors: Vlemmix T. , Piters A. J. M. , Stammes P. , Wang P. , Levelt P. F.
Published: October 2010

Abstract. Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) is a technique to measure trace gas amounts in the lower troposphere from ground-based scattered sunlight observations. MAX-DOAS observations are especially suitable for validation of tropospheric trace gas observations from satellite, since they have a representative range of several kilometers, both in the horizontal and in the vertical dimension. A two-step retrieval scheme is presented here, to derive aerosol corrected tropospheric NO2 columns from MAX-DOAS observations. In a first step, boundary layer aerosols, characterized in terms of aerosol optical thickness (AOT), are estimated from relative intensity observations, which are defined as the ratio of the sky radiance at elevation α and the sky radiance in the zenith. Relative intensity measurements have the advantage of a strong dependence on boundary layer AOT and almost no dependence on boundary layer height. In a second step, tropospheric NO2 columns are derived from differential slant columns, based on AOT-dependent air mass factors. This two-step retrieval scheme was applied to cloud free periods in a twelve month data set of observations in De Bilt, The Netherlands. In a comparison with AERONET (Cabauw site) a mean difference in AOT (AERONET minus MAX-DOAS) of −0.01±0.08 was found, and a correlation of 0.85. Tropospheric-NO2 columns were compared with OMI-satellite tropospheric NO2. For ground-based observations restricted to uncertainties below 10%, no significant difference was found, and a correlation of 0.88.
A novel technique for extracting clouds base height using ground based imaging
Authors: Hirsch E. , Agassi E. , Koren I.
Published: October 2010

Abstract. The height of a cloud in the atmospheric column is a key parameter in its characterization. Several remote sensing techniques (passive and active, either ground-based or on space-borne platforms) and in-situ measurements are routinely used in order to estimate top and base heights of clouds. In this article we present a novel method that combines thermal imaging from the ground and sounded wind profile in order to derive the cloud base height. This method is independent of cloud types, making it efficient for both low boundary layer and high clouds. In addition, using thermal imaging ensures extraction of clouds' features during daytime as well as at nighttime. The proposed technique was validated by comparison to active sounding by ceilometers (which is a standard ground based method), to lifted condensation level (LCL) calculations, and to MODIS products obtained from space. As all passive remote sensing techniques, the proposed method extracts only the height of the lowest cloud layer, thus upper cloud layers are not detected. Nevertheless, the information derived from this method can be complementary to space-borne cloud top measurements when deep-convective clouds are present. Unlike techniques such as LCL, this method is not limited to boundary layer clouds, and can extract the cloud base height at any level, as long as sufficient thermal contrast exists between the radiative temperatures of the cloud and its surrounding air parcel. Another advantage of the proposed method is its simplicity and modest power needs, making it particularly suitable for field measurements and deployment at remote locations. Our method can be further simplified for use with visible CCD or CMOS camera (although nighttime clouds will not be observed).
A new model of Holocene peatland net primary production, decomposition, water balance, and peat accumulation
Authors: Frolking S. , Roulet N. T. , Tuittila E. , Bubier J. L. , Quillet A. , Talbot J. , Richard P. J. H.
Published: October 2010

Abstract. Peatland carbon and water cycling are tightly coupled, so dynamic modeling of peat accumulation over decades to millennia should account for carbon-water feedbacks. We present initial results from a new simulation model of long-term peat accumulation, evaluated at a well-studied temperate bog in Ontario, Canada. The Holocene Peat Model (HPM) determines vegetation community composition dynamics and annual net primary productivity based on peat depth (as a proxy for nutrients and acidity) and water table depth. Annual peat (carbon) accumulation is the net balance above- and below-ground productivity and litter/peat decomposition – a function of peat hydrology (controlling depth to and degree of anoxia). Peat bulk density is simulated as a function of degree of humification, and affects the water balance through its influence on both the growth rate of the peat column and on peat hydraulic conductivity and the capacity to shed water. HPM output includes both time series of annual carbon and water fluxes, peat height, and water table depth, as well as a final peat profile that can be "cored" and compared to field observations of peat age and macrofossil composition. A stochastic 8500-yr, annual precipitation time series was constrained by a published Holocene climate reconstruction for southern Québec. HPM simulated 5.4 m of peat accumulation (310 kg C m-2) over 8500 years, 6.5% of total NPP over the period. Vascular plant functional types accounted for 65% of total NPP over 8500 years but only 35% of the final (contemporary) peat mass. Simulated age-depth and carbon accumulation profiles were compared to a radiocarbon dated 5.8 m, c.9000-yr core. The simulated core was younger than observations at most depths, but had a similar overall trajectory; carbon accumulation rates were generally higher in the simulation and were somewhat more variable than observations. HPM results were sensitive to century-scale anomalies in precipitation, with extended drier periods (precipitation reduced ∼10%) causing the peat profile to lose carbon (and height), despite relatively small changes in NPP.
Estimating strategies for Multiparameter Multivariate Extreme value copulas
Authors: Salvadori G. , De Michele C.
Published: October 2010

Abstract. Multivariate Extreme Value models are a fundamental tool in order to assess potentially dangerous events. Exploiting recent theoretical developments in the theory of Copulas, new multiparameter models can be easily constructed. In this paper we suggest several strategies in order to estimate the parameters of the selected copula, according to different criteria: these may use either a nearest neighbor or a nearest cluster approach, or exploit all the pair-wise relationships between the available gauge stations. An application to flood data is also illustrated and discussed.
The relationship between climate forcing and hydrological response in UK catchments
Authors: Arnell N. W.
Published: October 2010

Abstract. This paper assesses the relationship between amount of climate forcing – as indexed by global mean temperature change – and hydrological response in a sample of UK catchments. It constructs climate scenarios representing different changes in global mean temperature from an ensemble of 21 climate models assessed in the IPCC AR4. The results show a considerable range in impact between the 21 climate models, with – for example – change in summer runoff at a 2 °C increase in global mean temperature varying between −40% and +20%. There is evidence of clustering in the results, particularly in projected changes in summer runoff and indicators of low flows, implying that the ensemble mean is not an appropriate generalised indicator of impact, and that the standard deviation of responses does not adequately characterise uncertainty. The uncertainty in hydrological impact is therefore best characterised by considering the shape of the distribution of responses across multiple climate scenarios. For some climate model patterns, and some catchments, there is also evidence that linear climate change forcings produce non-linear hydrological impacts. For most variables and catchments, the effects of climate change are apparent above the effects of natural multi-decadal variability with an increase in global mean temperature above 1 °C, but there are differences between catchments. Based on the scenarios represented in the ensemble, it is likely that the effect of climate change in northern upland catchments will be seen soonest in indicators of high flows, but in southern catchments effects will be apparent soonest in measures of summer and low flows. The uncertainty in response between different climate model patterns is considerably greater than the range due to uncertainty in hydrological model parameterisation.
Intraplate seismicity in Canada: a graph theoretic approach to data analysis and interpretation
Authors: Vasudevan K. , Eaton D. W. , Davidsen J.
Published: October 2010

Abstract. Intraplate seismicity occurs in central and northern Canada, but the underlying origin and dynamics remain poorly understood. Here, we apply a graph theoretic approach to characterize the statistical structure of spatiotemporal clustering exhibited by intraplate seismicity, a direct consequence of the underlying nonlinear dynamics. Using a recently proposed definition of "recurrences" based on record breaking processes (Davidsen et al., 2006, 2008), we have constructed directed graphs using catalogue data for three selected regions (Region 1: 45°−48° N/74°−80° W; Region 2: 51°−55° N/77°−83° W; and Region 3: 56°−70° N/65°−95° W), with attributes drawn from the location, origin time and the magnitude of the events. Based on comparisons with a null model derived from Poisson distribution or Monte Carlo shuffling of the catalogue data, our results provide strong evidence in support of spatiotemporal correlations of seismicity in all three regions considered. Similar evidence for spatiotemporal clustering has been documented using seismicity catalogues for southern California, suggesting possible similarities in underlying earthquake dynamics of both regions despite huge differences in the variability of seismic activity.
Gold Nanocages: A Novel Class of Multifunctional Nanomaterials for Theranostic Applications
Authors: Chen Jingyi , Yang Miaoxin , Zhang Qiang , Cho Eun Chul , Cobley Claire M. , Kim Chulhong , Glaus Charles , Wang Lihong V. , Welch Michael J. , Xia Younan
Published: October 2010

Gold nanocages represent a novel class of nanostructures, well‐suited for biomedical applications. They can be readily prepared via the galvanic replacement reaction between silver nanocubes and chloroauric acid. Their optical resonance peaks can be easily and precisely tuned to the near‐infrared region from 650–900 nm, the transparent window for blood and soft tissue. Furthermore, their surface can be conveniently conjugated with various ligands for targeting cancer. In this feature article, we highlight recent advances in the large‐scale synthesis of gold nanocages and their applications in cancer diagnosis and treatment. Specifically, we have scaled up the production of gold nanocages for in vivo studies and evaluated their tumor targeting capabilities. We have also demonstrated their use as contrast agents for photoacoustic tumor imaging and the mapping of sentinel lymph node, as photothermal transducers for cancer treatment, and as smart carriers for controlled release with a near‐infrared laser.
Enzymnachbildungen auf der Basis supramolekularer Koordinationschemie
Authors: Wiester Michael J. , Ulmann Pirmin A. , Mirkin Chad A.
Published: October 2010

In der aktuellen supramolekularen Koordinationschemie können makromolekulare Komplexe mit Enzymeigenschaften synthetisiert werden. Dieser Aufsatz behandelt solche Strukturen, die nicht in erster Linie die aktiven Zentren von Enzymen nachbilden sollen, sondern von deren Eigenschaften und Funktionen inspiriert sind. Die Komplexe werden in konvergenter Weise mit modularen Methoden in hohen Ausbeuten synthetisiert, wobei ihre Größe, Form und Eigenschaften maßgeschneidert werden können. Viele der Strukturen zeigen eine Reaktivität und Spezifität, die an natürliche Systeme erinnern, und manche haben Funktionen, die über jene ihrer Vorbilder hinausgehen.
Reductive Dehydroxylation of Allyl Alcohols by IspH Protein
Authors: Gräwert Tobias , Span Ingrid , Bacher Adelbert , Groll Michael
Published: October 2010

The biosynthesis of natural products is a treasure trove of unusual reaction mechanisms. This Minireview summarizes recent work on the structure and mechanism of IspH protein, which catalyzes the reductive dehydroxylation of an allyl alcohol in a biosynthetic pathway leading to isoprenoid precursors.
Climate Change and Atmospheric Chemistry: How Will the Stratospheric Ozone Layer Develop?
Authors: Dameris Martin
Published: October 2010

The discovery of the ozone hole over Antarctica in 1985 was a surprise for science. For a few years the reasons of the ozone hole was speculated about. Soon it was obvious that predominant meteorological conditions led to a specific situation developing in this part of the atmosphere: Very low temperatures initiate chemical processes that at the end cause extreme ozone depletion at altitudes of between about 15 and 30 km. So‐called polar stratospheric clouds play a key role. Such clouds develop at temperatures below about 195 K. Heterogeneous chemical reactions on cloud particles initiate the destruction of ozone molecules. The future evolution of the ozone layer will not only depend on the further development of concentrations of ozone‐depleting substances, but also significantly on climate change.
Supramolecular Porphyrin–DABCO Array in Single‐ and Double‐Stranded Polynorbornenes
Authors: Wang Hsien‐Wen , Chen Chih‐Hsien , Lim Tsong‐Shin , Huang Shou‐Ling , Luh Tien‐Yau
Published: October 2010

Zinc–porphyrin‐appended norbornene derivative 6, the corresponding dimer 7, coherently aligned single‐stranded polynorbornene 5, and zinc–porphyrin‐linked double‐stranded polymeric ladderphane 3 have been used for complexation with 1,4‐diazabicyclo[2.2.2]octane (DABCO) to generate an array of porphyrin–DABCO supramolecular scaffolds. The stoichiometries of the complex formation are analyzed in detail by 1H NMR spectroscopy as well as absorption and emission spectroscopic methods. Bidentate ligand DABCO is found to form with 7, 5, and 3 to give 2‐to‐1 porphyrin–DABCO sandwich structures. Monomer 6, on the other hand, forms a 2‐to‐1 porphyrin–DABCO sandwich structure at high concentration (20 mM), but a 1‐to‐1 porphyrin–DABCO complex at low concentration (10−6 M). Time‐resolved fluorescence decays revealed a similar behavior for the 2‐to‐1 porphyrin–DABCO sandwich structures that are formed from 3, 5, and 7.
Review of open and minimal access approaches to oesophagectomy for cancer
Authors: Safranek P M , Cubitt J , Booth M I , Dehn T C B
Published: October 2010

Background

Minimally invasive approaches to oesophagectomy are being used increasingly, but there remain concerns regarding safety and oncological acceptability. This study reviewed the outcomes of totally minimally invasive oesophagectomy (MIO; 41 patients), hybrid procedures (partially minimally invasive; 34) and open oesophagectomy (46) for oesophageal cancer from a single unit.

Methods

Demographic and clinical data were entered into a prospective database. MIO was thoracoscopic–laparoscopic–cervical anastomosis, hybrid surgery was thoracoscopic–laparotomy or laparoscopic gastric mobilization–thoracotomy, and open resections were left thoracoabdominal (LTA), Ivor Lewis (IL) or transhiatal oesophagectomy (THO).

Results

There were 118 resections for carcinoma (23 squamous cell carcinoma, 95 adenocarcinoma) and three for high-grade dysplasia. MIO took longer than open surgery (median 6·5 h versus 4·8 h for THO, 4·7 h for IL and LTA). MIO required less epidural time (P < 0·001 versus IL and LTA, P = 0·009 versus thorascopic hybrid, P = 0·014 versus laparoscopic IL). Despite a shorter duration of single-lung ventilation with MIO compared with IL and LTA (median 90 versus 150 min; P = 0·013), respiratory complication rates and duration of hospital stay were similar. There were seven anastomotic leaks after MIO, four after hybrid procedures and one following open surgery. Mortality rates were 2, 6 and 2 per cent respectively. Lymph node harvests were similar between all groups, as were rates of complete (R0) resection in patients with locally advanced tumours.

Conclusion

MIO is technically feasible. It does not reduce pulmonary complications or length of stay. Oncological outcomes appear equivalent.
Cost-effectiveness of traditional and endovenous treatments for varicose veins
Authors: Gohel M S , Epstein D M , Davies A H
Published: October 2010

Background

The aim of this study was to evaluate the cost-effectiveness of traditional and endovenous treatments for patients with primary great saphenous varicose veins.

Methods

A Markov model was constructed to compare costs and quality-adjusted life years (QALYs) for great saphenous vein (GSV) reflux. Eight popular treatment strategies were compared up to 5 years. Estimates for the effectiveness of treatments were obtained from published randomized studies and cost values were obtained from published National Health Service (NHS) healthcare resource group tariffs and device manufacturers. Parameter uncertainty was tested using sensitivity analysis and Monte Carlo simulation.

Results

Ultrasound-guided foam sclerotherapy (UGFS) had the lowest initial cost, but a higher requirement for further interventions. Day-case surgery (with concomitant treatment of varicosities), endovenous laser ablation (EVLA) and radiofrequency ablation (RFA) performed in an outpatient or office setting (with staged treatment of varicosities) were likely to be cost-effective treatment strategies. The incremental cost-effectiveness ratio (ICER) for UGFS (versus conservative care), EVLA (versus UGFS) and RFA (versus EVLA) were £1366, £5799 and £17 350 per QALY respectively. The ICER for traditional surgery (performed on a day-case basis) was £19 012 compared with RFA. Other strategies were not cost-effective using the NHS threshold of £20 000 per QALY.

Conclusion

Day-case surgery or endovenous ablation using EVLA or RFA performed as an outpatient are likely to be cost-effective treatment strategies for patients with primary unilateral GSV reflux requiring treatment.
The strategic leadership of complex practice: opportunities and challenges
Authors: Morrison Tony
Published: October 2010

This paper addresses the issue of how strategic‐level partnerships, such as Local Safeguarding Children Boards, know about and learn from practice. The death of Baby Peter in Haringey exposed the dangers of reliance on numerical performance data alone to inform leaders about the true state of practice. The drivers for, and impact of, regulatory, media and political pressures on front‐line practice and partnership behaviour are discussed with reference to the rise of organisational risk management and ‘rule‐based’ responses (Munro, 2009). These are exacerbated by an overload of negative data about child protection systems which results in contagious ‘attention cascades’ which lead to over‐simplification of complex issues and the rush to quick‐fix solutions. This results in compliance‐based responses designed to avoid ‘blame’, based on individualistic analyses of complex situations. Under these conditions, ‘learning’, such as from serious case reviews, can become regressive (how to avoid future culpability) rather than progressive (how to improve knowledge skills and practice). It is argued that understanding and improving practice require strategic partnerships to have engaged with front‐line staff in order to access practice narratives as well as performance numbers, and to achieve an accurate and systemic analysis of the state of practice and how it can be improved. This calls for collective forms of knowing and reflecting and the paper concludes by describing examples. Copyright © 2010 John Wiley & Sons, Ltd.
FtsK DNA Translocase: The Fast Motor That Knows Where It's Going
Authors: Crozat Estelle , Grainge Ian
Published: October 2010

FtsK is a double‐stranded DNA translocase, a motor that converts the chemical energy of binding and hydrolysing ATP into movement of a DNA substrate. It moves DNA at an amazing rate—>5000 bp per second—and is powerful enough to remove other proteins from the DNA. In bacteria it is localised to the site of cell division, the septum, where it functions as a DNA pump at the late stages of the cell cycle, to expedite cytokinesis and chromosome segregation. The N terminus of the protein is involved in the cell‐cycle‐specific localisation and assembly of the cell‐division machinery, whereas the C terminus forms the motor. The motor portion of FtsK has been studied by a combination of biochemistry, genetics, X‐ray crystallography and single‐molecule mechanical assays, and these will be the focus here. The motor can be divided into three subdomains: α, β and γ. The α and β domains multimerise to produce a hexameric ring with a central channel for dsDNA, and contain a RecA‐like nucleotide‐binding/hydrolysis fold. The motor is given directionality by the regulatory γ domain, which binds to polarised chromosomal sequences—5′‐GGGNAGGG‐3′, known as KOPS—to ensure that the motor is loaded onto DNA in a specific orientation such that subsequent translocation is always towards the region of the chromosome where replication usually terminates (the terminus), and specifically to the 28 bp dif site, located in this region. Once the FtsK translocase has located the dif site it then interacts with the XerCD site‐specific recombinases to activate recombination.
Tuning the HOMO Energy Levels of Organic Dyes for Dye‐Sensitized Solar Cells Based on Br−/Br3− Electrolytes
Authors: Teng Chao , Yang Xichuan , Li Shifeng , Cheng Ming , Hagfeldt Anders , Wu Li‐zhu , Sun Licheng
Published: October 2010

A series of novel metal‐free organic dyes TC301–TC310 with relatively high HOMO levels were synthesized and applied in dye‐sensitized solar cells (DSCs) based on electrolytes that contain Br−/Br3− and I−/I3−. The effects of additive Li+ ions and the HOMO levels of the dyes have an important influence on properties of the dyes and performance of DSCs. The addition of Li+ ions in electrolytes can broaden the absorption spectra of the dyes on TiO2 films and shift both the LUMO levels of the dyes and the conduction band of TiO2, thus leading to the increase of Jsc and the decrease of Voc. Upon using Br−/Br3− instead of I−/I3−, a large increase of Voc is attributed to the enlarged energy difference between the redox potentials of electrolyte and the Fermi level of TiO2, as well as the suppressed electron recombination. Incident photon to current efficiency (IPCE) action spectra, electrochemical impedance spectra, and nanosecond laser transient absorption reveal that both the electron collection yields and the dye regeneration yields (Φr) depend on the potential difference (the driving forces) between the oxidized dyes and the Br−/Br3− redox couple. For the dyes for which the HOMO levels are more positive than the redox potential of Br−/Br3− sufficient driving forces lead to the longer effective electron‐diffusion lengths and almost the same efficient dye regenerations, whereas for the dyes for which the HOMO levels are similar to the redox potential of Br−/Br3−, insufficient driving forces lead to shorter effective electron‐diffusion lengths and inefficient dye regenerations.