bluuebunny/crossref_metadata_2025 huggingface dataset:
BUCKLING OF SLENDER COMPOSITE CONCRETE‐FILLED STEEL COLUMNS
Authors: Goode C. Douglas , Kuranovas Artiomas , Kvedaras Audronis Kazimieras
Published: June 2010

The paper presents the analysis of the experimental data of 1817 on concrete‐filled steel tubes ‐ CFSTs. These results are compared with the predicted results of the load‐bearing capacity of calculations of slender elements according to the methods suggested by Eurocode 4. The following types of tested CFSTs were analysed: circular and rectangular hollow section stub and long columns fully filled with concrete, which were with or without applied moments at the ends of specimen. During the results obtained in the result of the tests on the load bearing capacity for circular concrete‐filled steel tubular columns correspond with the calculated values based on methods presented by Eurocode 4. The experimental values of load bearing capacity for members of concrete‐filled rectangular hollow sections agree very well with the theoretical values where the concrete cylinder strength is below 75 N/mm2. The analysis demonstrated that preloading of concrete‐filled hollow section members does not influence the load bearing capacity. This paper also presents the examination of stress state distribution for concrete‐filled hollow section members, influence of concrete preloading and of longitudinal stress strain curves. Santrauka Straipsnyje aptariami 1817 betonšerdžiu plieniniu vamzdiniu strypu eksperimentiniai duomenys. Šie duomenys lyginami su rezultatais, gautais remiantis Eurocode 4 pateiktais kompozitiniu elementu laikomosios galios nustatymo metodais. Analizuojami tokie betonšerdžiu plieniniu strypu bandiniu tipai: pilnavidures trumpos arba liaunos apskritojo ir stačiakampio skerspjūvio vamzdines betonšerdes plienines kolonos su ju galuose veikiančiu lenkiamuoju momentu arba be jo. Apskritojo skerspjūvio betonšerdžiu kolonu bandymu metu gautieji laikomosios galios rezultatai atitinka remiantis Eurocode 4 pateiktais metodais apskaičiuotasias ju reikšmes. Stačiakampio skerspjūvio betonšerdžiu elementu laikomosios galios bandymais rastosios reikšmes labai gerai atitinka teorines reikšmes, kai šerdies betono ritininis stipris nesiekia 75 N/mm2. Analizuojant nustatyta, kad išankstinis betonšerdžiu elementu apkrovimas neturi beveik jokio poveikio elementu laikomajai galiai. Šiame straipsnyje taip pat nagrinejamas betonšerdžiu elementu itempiu būviu pasiskirstymas, betono apspaudimo poveikis bei išilginiu deformaciju ir itempiu kreives.
INFLUENCE OF THE SEMI‐RIGID BOLTED STEEL JOINTS ON THE FRAME BEHAVIOUR
Authors: Daniūnas Alfonsas , Urbonas Kęstutis
Published: June 2010

This research work describes the analysis of steel semi rigid joints that are subjected to bending and tension or compression. The main attention is focussed on the beam‐to‐beam and plate bolted joints. Usually influence of axial force is neglected. In fact, the level of tension or compression of axial force can be significant and has some impact on joint behaviour and on its stiffness and strength characteristics. Nowadays the most powerful method for the estimation of joints characteristics is the component method. The adaptation of the component method for the determination of joints characteristics under bending ant axial forces is shown in the paper. Some numerical results of calculations of steel frameworks are presented in this paper as well (Daniūnas and Urbonas 2008). Santrauka Straipsnyje nagrinejami pusiau standūs mazgai, veikiami lenkiamojo momento ir tempimo ar gniuždymo ašines jegos. Daugiausia demesio skiriama sijos, sujungtos varžtais per galines plokšteles su kita sija, mazgui. Dažniausiai teigiama, kad ašines jegos itaka mazgo elgsenai yra nereikšminga. Iš tikruju gniuždymo ar tempimo ašines jegos dydis gali būti reikšmingas ir daryti svaria itaka mazgo elgsenai, sukamojo standžio ir lenkiamosios galios reikšmems. Populiariausias ir plačiausiai šiuo metu taikomas metodas mazgo charakteristikoms nustatyti yra komponentu metodas. Šiame straipsnyje rodoma, kaip taikomas komponentu metodas nustatyti mazgo, veikiamo lenkiamojo momento ir ašines jegos, charakteristikoms. Pateikiami ir plieniniu reminiu konstrukciju skaičiavimu rezultatai (Daniūnas, Urbonas 2008).
MULTIPLE CRITERIA ASSESSMENT OF ALTERNATIVES FOR BUILT AND HUMAN ENVIRONMENT RENOVATION
Authors: Tupenaite Laura , Zavadskas Edmundas Kazimieras , Kaklauskas Arturas , Turskis Zenonas , Seniut Mark
Published: June 2010

The built environment is not constructed in empty space. It refers to human ‐ made spaces they live and work in and which are affected by various micro, meso and macro level factors. For this purpose, renovation decisions must be considered avoiding a narrow approach to the single projects of building renovation. Renovation of the built and human environment must be considered instead and the holistic approach used. From this perspective, decision‐making problems of renovation often involve a complex decision making process in which multiple requirements and conditions have to be taken into consideration simultaneously. This paper describes the concept of the integrated analysis of built and human environment renovation as a whole as well as presents the multiple criteria assessment of alternatives of the Bulgarian cultural heritage renovation projects. The widely known multiple criteria assessment methods SAW, TOPSIS and COPRAS and the newly developed method ARAS were used for this purpose. As a result the best project for granting was selected. Santrauka Gyvenamoji aplinka sukurta žmoniu ir skirta ju poreikiams tenkinti, ja veikia daugybe makro‐, mezo‐ ir mikroaplinkos veiksniu. Kadangi gyvenamoji aplinka yra kompleksiška, jos atnaujinimo sprendimai turi būti priimami vengiant pernelyg siauro požiūrio, nagrinejant tik pavieniu pastatu atnaujinimo projektus. Atnaujinimo sprendimai turetu būti priimami ir projektai igyvendinami taikant holistini požiūri. Šiuo požiūriu atnaujinimo sprendimai yra sudetingi, juos priimant būtina atsižvelgti i daugeli salygu ir reikalavimu. Šiame straipsnyje gyvenamosios aplinkos atnaujinimas nagrinejamas kaip visuma, pateikiamas autoriu sukurtas integruotas gyvenamosios aplinkos atnaujinimo analizes modelis, atliekama Bulgarijos kultūros paveldo atnaujinimo projektu daugiakriterine analize taikant gerai žinomus daugiakriterinio vertinimo metodus SAW, TOPSIS ir COPRAS bei naujai sukurta metoda ARAS. Atlikus tyrima išrenkamas geriausias atnaujinimo projektas, kuriam gali būti suteiktas finansavimas.
SELECTION MODEL OF REPRESENTATIVE ITEMS FOR THE SUBCONTRACTORS’ COST INDEX IN MULTI‐FAMILY HOUSING PROJECTS
Authors: Park Sung-Chul , Hong TaeHoon , Koo Kyo-Jin , Hyun Chang-Taek
Published: June 2010

Price index has played an important role in measuring the past performance of an industry, which it does by tracking the cost of the items used in the industry. It is the most widely used industry performance indicator because a small number of representative items covers a wide range of costs. The construction industry consists of various facility types that can be organized into many subcontractors’ works. Unfortunately, the existing cost indexes have difficulty monitoring the fluctuation of the subcontractors’ costs since they select representative items in macro‐scale terms, such as the type of construction or facility. Therefore, this study was conducted to develop a selection model that can select the effective representative items included in the subcontractors’ costs. To determine the characteristics of the subcontractors’ costs, the curve estimation function of SPSS® 12.0 for Windows was applied to the priced bills of quantities of 30 multi‐family housing projects. The results of the analysis show that the relationship between the coverage ratio and the percentage of the number of representative items follows Pareto's principle. Based on this, a selection model of representative items was developed, using the tangent function. The case study that was conducted to verify the usability of the model revealed that the proposed model can efficiently select the effective representative items from the cost items of each subcontractor's work included in multi‐family housing projects. Santrauka Kainos rodiklis yra labai svarbus analizuojant igyvendintus projektus ir yra tiriamas naudojamu tipiniu produktu pramoneje. Tai plačiai naudojamas pramones veiklos rodiklis, tačiau nedaugeliui tipiniu produktu būdingas platus kainu diapazonas. Statybos pramone apima ivairias paslaugu rūšis, kuriu daugeli teikia subrangovai. Deja, esami kainos rodiklio subrangovu išlaidu svyravimai sunkiai kontroliuojami, nes tipiniai produktai, tokie kaip statybos būdas ar gebejimai, atrenkami makroskales požiūriu. Todel šis tyrimas buvo atliktas siekiant sukurti atrankos modeli, pagal kuri būtu galima pasirinkti naudingiausia tipini produkta ir ivertinti subrangovu išlaidas. Subrangovu sanaudu charakteristikoms nustatyti taikyti kreives funkcijos skaičiavimai SPSS® 12.0 Windows, naudoti 30 daugiabučiu namu projektu ikainojimo dokumen‐tai. Tyrimu rezultatai rodo, kad santykis tarp apimčiu koeficiento ir tipiniu produktu procento pagristas Pareto principu. Juo remiantis buvo sukurtas tipiniu produktu atrankos modelis, taikant tangento funkcija. Atvejo tyrimas, atliktas siekiant patikrinti modelio naudojima, atskleide, kad numatomas atrankos modelis gali racionaliai parinkti kiekvieno subrangovo darbus pagal naudingiausius tipinius elementus, kurie itraukti i daugiabučiu namuprojektus.
COMPLEX EVALUATION OF CONTRACTS FOR CONSTRUCTION
Authors: Podvezko Valentinas , Mitkus Sigitas , Trinkūnienė Eva
Published: June 2010

The effectiveness of construction processes largely depends on the effective contract preparation. To draw an effective contract for construction, the methods of assessment and comparison of these types of contract should be developed. In recent years, multicriteria methods have been widely used for evaluating various complex phenomena. The development of construction evaluation methods requires the analysis of construction technology and organization, as well as economic factors and legal aspects of contracting in construction. In the present investigation, the criteria describing contracts for construction from various perspectives are determined based on the estimates elicited from experts. The weights of nine criteria used in complex evaluation of construction contracts are determined based on the use of the AHP method. The consistency of expert estimates is also assessed. Using multicriteria evaluation methods, construction contracts are compared and the best alternative is determined. Santrauka Didele reikšme statybos proceso efektyvumui turi tinkamas statybos rangos sutarties sudarymas. Siekiant sudaryti efektyvias statybos rangos sutartis, reikia sukurti rangos sutarčiu ivertinimo ir palyginimo metodikas. Pastaruoju metu sudetingiems procesams vertinti plačiai taikomi daugiakriteriniai vertinimo metodai. Ju vertinimas priklauso nuo rodikliu, charakterizuojančiu procesa, ir ju reikšmingumo. Siekiant parengti statybos vertinimo metodikas, reikia išnagrineti ne tik techninius, organizacinius, ekonominius, bet ir teisinius statybos rangos sutarties aspektus. Taikant ekspertu vertinimus, buvo nustatyti rodikliai, charakterizuojantys statybos rangos sutarties turini. Kompleksiškai ivertinant statybos rangos sutartis AHP metodu nustatyti devyniu rodikliu svoriai, ivertintas ekspertu nuomoniu suderinamumas. Taikant daugia‐kriterinius metodus tarpusavyje palygintos statybos rangos sutartys ir nustatytas geriausias variantas.
THE EFFECT OF THE FOURIER NUMBER ON CALCULATION OF AN UNSTEADY HEAT TRANSFER OF BUILDING WALLS
Authors: Pupeikis Darius , Stankevičius Vytautas , Burlingis Arūnas
Published: June 2010

When the temperature changes in any side of construction, the heat flow diffusing through construction also changes and it is varying until the stabilized steady state conditions is reached. In real terms, the heat exchange process in buildings is an unsteady state, consequently varying in time. Volatility of the heat exchange process is influenced by oscillating external temperature, internal heat gains, solar radiation and other factors that affect the heat balance of building. While calculating unsteady heat exchanges, it is important to divide the material into the right number of conditional layers. A conditional layer is material's thickness, in which an assumed process of steady heat transfer takes place. The time step is the second parameter which affects the accuracy of calculation of unsteady heat transfer. This parameter defines time during which temperature diffuses step by step through the conditional layer. Thermal diffusivity is the last parameter, which defines the equalization speed of the temperature in conditional layer. A combination of all these parameters is expressed as the Fourier number. Our research has showed that it's rational to divide layers of enclosure into equal thermal diffusions. Also, the cooling (heating) speed and the acceleration values of conditional layers significantly affect the accuracy of calculation. Santrauka Pasikeitus temperatūrai bet kurioje atitvaros pusese, pasikeičia ir šilumos srautas, sklindantis per atitvara, kuris kinta tol, kol tampa nuolatinis (stacionarus), atsiranda šilumine pusiausvyra. Realiomis salygomis šilumos mainai pastatuose vyksta nestacionarios būkles, t. y. kinta laiko atžvilgiu. Šiluminiu mainu procesu nepastovumas atsiranda svyruojant lauko oro temperatūrai, išsiskiriant šilumos pritekejimams pastate, veikiant saules spinduliuotei ar kitiems veiksniams, kurie daro itaka šiluminiam visapastato balansui. Skaičiuojant nestacionariuosius šilumos mainus, svarbu tinkamai sudalinti medžiaga reikiamu sluoksneliu skaičiumi. Sluoksnelis ‐ tai medžiagos storis, kuriame menamai vyksta stacionarus šilumos perdavimas. Laiko žingsnis, kuriuo temperatūra šuoliuoja per sluoksnelius, ir temperatūrinis laidis, kuris išreiškia temperatūros suvienodejimo sparta, tai dar du parametrai, darantys poveiki skaičiavimo tikslumui. Visu šiu parametru derinys išreiškiamas Furje kriterijumi. Atlikti tyrimai parode, kad sluoksnelius racionalu sudalinti vienodomis temperatūrinemis pralaidomis, o sluoksneliu aušimo (šilimo) greičio ir pagreičio vertes daro svaria itaka skaičiavimo tikslumui.
The eradication of smallpox, a success story for modern medicine and public health: What lessons for the future?
Authors: Tognotti Eugenia
Published: June 2010

This item has no abstract. Use the links below to access the full text.
Triple-Vessel Percutaneous Coronary Revascularization In Situs Inversus Dextrocardia
Authors: Kakouros Nikolaos , Patel Sundip J. , Redwood Simon , Wasan Balvinder S.
Published: June 2010

Dextrocardia with situs inversus occurs in approximately one in 10,000 individuals of whom 20% have primary ciliary dyskinesia inherited as an autosomal recessive trait. These patients have a high incidence of congenital cardiac disease but their risk of coronary artery disease is similar to that of the general population. We report what is, to our knowledge, the first case of total triple-vessel coronary revascularization by percutaneous stent implantation in a 79-year-old woman with situs inversus dextrocardia. We describe the successful use of standard diagnostic and interventional guide catheters with counter rotation and transversely inversed image acquisition techniques. The case also highlights that the right precordial pain may represent cardiac ischemia in this population.
What is religion? An African understanding
Authors: Beyers Jaco
Published: June 2010

Western thought has influenced the way that religion is understood. Western philosophy supported the separation between the sacred and the profane. Modernism, focusing on human rationality, reduced religion to a set of correctly formulated dogmas and doctrines. Western thought, dominated by Christianity, created a hierarchical structure of world religions through a theology of religions. Can an African understanding of religion make a contribution to the understanding of what religion is? Such a question requires an African understanding of religion, as well as an understanding of African religion. From an African perspective, religion emphasises the human effort to systematise, in society, the continuation of a religious experience relevant to a specific context. Tradition, expressed in rituals and ethics, becomes the social expression of these religious experiences. African religion tends not to differentiate the transcendental from the earthly. African scholars do not present one unified understanding of religion. Some scholars would even argue that an African understanding is nothing more than an internalised form of Western perspectives. To characterise African Traditional Religion as a separate type of religion minimises the contribution that an African understanding can make to religion.
Childhood cancers in a referral hospital in northern Nigeria
Authors: Mohammed A , Aliyu H O
Published: June 2010

Background:We undertook this study to determine the relative frequencies of childhood malignancies and their age - sex distribution in this environment.Materials and Methods:Hospital-based data of histological and cytologically confirmed cases of malignancies in children, aged ≤ 15 years, was collated over a period of 11 years, from the Cancer Registry.Results:A total of 329 children aged ≤ 15 years, with confirmed malignant disease, was recorded. This constituted 8.44% of all malignancies diagnosed in the same period with a Male : Female ratio of 1.5:1. Burkitt′s lymphoma accounted for 27.01% of the cases followed by retinoblastoma (17.02%), non-Hodgkin′s non-Burkitt′s Lymphoma (9.42%), and Rhabdomyosarcoma (9.42%). Others were Nephroblastoma (8.81%), Hodgkin′s lymphoma (6.69%), Neuroblastoma (3.34%), Colorectal carcinoma (2.43%), Osteosarcoma (2.13%), and Unspecified lymphomas (1.82%). Burkitt′s lymphoma was most prevalent in the 5-9 and 10-15 year age groups, retinoblastoma in the 0-4 year age group, and Non-Hodgkin′s lymphoma, Hodgkin′s lymphoma, and unspecified carcinomas were more prevalent in the 10-15 year age group.Conclusion:Lymphomas were the most prevalent malignancies of childhood seen in this region and the majority were of the Burkitt type, in contrast to the predominant leukemic and central nervous system trend seen in developed nations.
Expression of human chorionic gonadotropin beta in gastric carcinoma: A retrospective immunohistochemical study
Authors: Murhekar Kanchan M , Anuratha Jayaram N , Majhi Urmila , Rajkumar Thangarajan
Published: June 2010

Context:Beta Human Chorionic Gonadotropin (βHCG), a marker of the trophoblastic neoplasm, is also secreted by non-trophoblastic neoplasms including gastric carcinomas. Its role in disease progression remains unclear.Aim:To investigate the incidence of βHCG positivity in gastric carcinomas and correlate its presence with the biological behavior of the tumor.Setting and Design:A hospital-based, immunohistochemical study.Materials and Methods:One hundred and fifty formalin-fixed, paraffin-embedded tissue specimens from histopathologically confirmed cases of gastric carcinoma were immunostained using an indigenously developed antibody against βHCG. Tumors with diffuse reactivity to βHCG were considered as positive. Those with occasional, focal or no reactivity to βHCG were considered as negative.Statistical Analysis:Differences in βHCG staining were compared according to the histological grade and surgical stage using the χ2test. Using the Cox proportional hazards model, the time till the onset of development of an adverse outcome after surgery (defined as death, local or distant metastasis) was compared between the bHCG positive and negative tumors.Results:Twenty-eight (18.7%) of the 150 specimens were βHCG positive. No association was found between the histological grade (P=0.49) and the surgical stage (P=0.19) with βHCG positivity. The median disease-free survival after surgery was not different among bHCG positive and negative tumors. Risk of an adverse outcome after surgery was significantly associated with the stage of the tumor (Hazard ratio=2.9, 95% confidence interval: 1.1-7.4). No association was observed with grade or βHCG positivity.Conclusion:βHCG immunoreactivity was observed in about one-fifth of the gastric cancers. bHCG reactivity, however, played no role in the biological behavior.
Persistent hypokalemia in an acute lymphoblastic leukemia patient
Authors: Ali Altaf , Aziz Sheikh Ajaz , Khan Afaq , Gelani Sajad
Published: June 2010

Nephrotoxicity is an important adverse effect of Amphotericin B, and although risk factors for nephrotoxicity in adults have been investigated, studies examining nephrotoxicity in the pediatric population are scarce. We describe case of 10 year old boy (CALLA - VE B cell ALL) who received conventional Amphotericin-B, but he persisted with hypokalemia.
Ganglioneuroma of the retroperitoneum presenting as a pediatric renal mass
Authors: Cyriac Sanju , Srinivas Lakshmi , Kathiresan N , Sundersingh Shirley , Mahajan Vandana , Sagar T.G.
Published: June 2010

Ganglioneuroma is the benign representative of peripheral neuroblastic tumors, with localized and predominant thoracic presentations in older children. They often have an excellent outcome with surgery alone. A 12-year-old girl presented with an incidentally detected abdominal mass, which was clinicoradiologically a renal mass. Laparotomy revealed a mass adherent to the anterior surface of the right kidney. The mass was carefully dissected out, sacrificing a portion of the inferior vena cava. Histopathological diagnosis was that of a ganglioneuroma. She was kept under follow up.
Follicular mycosis fungoides - A report of four Indian cases
Authors: Rajalakshmi T , Inchara Y.K. , Antony Meryl
Published: June 2010

Background:Follicular Mycosis Fungoides (FMF) is an under-recognized disease in India. Its clinical mimics include Hansen′s disease and Sarcoidosis.Aims:To describe the clinical and pathological features of FMF.Materials and Methods:All cases of FMF between January and December 2007 were retrieved. Cases of conventional epidermotropic MF with a minor follicular component were excluded. Slides were reviewed by two observers. The following criteria were assessed: degree and density of folliculotropism of lymphocytes, location of folliculotropism (infundibular / isthmic / bulbar), follicular mucin, eosinophils, granulomas, and conventional epidermotropism. Each feature was assigned a semi-quantitative grade.Results:There were four cases of FMF, with an equal gender distribution and a mean age of 17.5 years. All lesions were on the face. They presented as: hypopigmented patches (2) and erythematous plaques (2). Alopecia was seen in two cases. The clinical diagnosis was Hansen′s disease in all four, with a differential of Alopecia mucinosa / Sarcoidosis in two cases.The histological features seen were: disproportionate folliculotropism, lymphocyte tagging with haloes, follicular mucin, and nucleomegaly / convolution in all four cases, prominent eosinophils (2), epithelioid granulomas (1), eccrine infiltration (4), parakeratosis at the follicular ostia (2), and sebaceotropism (1). The infiltrate was bulbar (4) and isthmic (2). The rest of the epidermis showed no hint of conventional MF.Conclusion:The preferential features for FMF were involvement of face, dominant folliculotropism, nuclear atypia and convolution, and follicular mucin. Presence of granulomas and eosinophils necessitated exclusion of infectious causes. The absence of findings of MF in the rest of the epidermis should not deter pathologists from rendering this diagnosis.
Uterine C-Kit positive low grade stromal sarcoma
Authors: Martin Jovitha , Ramesh Anita , Kuruvilla Sarah , Lalitha D
Published: June 2010

Uterine C-Kit positive stromal tumors are rare, however, there are a few cases reported in literature. A 58-year-old post menopausal lady presented with bleeding per vaginum. An abdominal examination revealed an enlarged uterus. A computed tomography scan of the abdomen and pelvis showed a large myomatous uterus, with a probable subserosal intramural and intracavitary myoma or cervical myoma in the presence of a solitary large aortocaval node, with multiple bone lesions. The biopsy taken from the uterine mass had revealed, a low-grade uterine sarcoma, which was positive for CD117. This case is presented for its rarity and management dilemma.
Water uptake and chemical composition of fresh aerosols generated in open burning of biomass
Authors: Carrico C. M. , Petters M. D. , Kreidenweis S. M. , Sullivan A. P. , McMeeking G. R. , Levin E. J. T. , Engling G. , Malm W. C. , Collett J. L.
Published: June 2010

Abstract. As part of the Fire Lab at Missoula Experiments (FLAME) in 2006–2007, we examined hygroscopic properties of particles emitted from open combustion of 33 select biomass fuels. Measurements of humidification growth factors for subsaturated water relative humidity (RH) conditions were made with a hygroscopic tandem differential mobility analyzer (HTDMA) for dry particle sizes of 50, 100 and 250 nm. Results were then fit to a single-parameter model to obtain the hygroscopicity parameter, κ. Particles in freshly emitted biomass smoke exhibited a wide range of hygroscopicity (individual modes with 0
Can 3-D models explain the observed fractions of fossil and non-fossil carbon in and near Mexico City?
Authors: Hodzic A. , Jimenez J. L. , Prévôt A. S. H. , Szidat S. , Fast J. D. , Madronich S.
Published: June 2010

Abstract. A 3-D chemistry-transport model has been applied to the Mexico City metropolitan area to investigate the origin of elevated levels of non-fossil (NF) carbonaceous aerosols observed in this highly urbanized region. High time resolution measurements of the fine aerosol concentration and composition, and 12 or 24 h integrated 14C measurements of aerosol modern carbon have been performed in and near Mexico City during the March 2006 MILAGRO field experiment. The non-fossil carbon fraction (fCNF), which is lower than the measured modern fraction (fCM) due to the elevated 14C in the atmosphere caused by nuclear bomb testing, is estimated from the measured fCM and the available source information. The fCNF contained in PM1 total carbon (fCNFTC) ranged from 0.37 to 0.67 at the downtown location (T0), and from 0.50 to 0.86 at the suburban site T1. Substantially lower values (i.e. 0.24–0.49) were found for PM10 filters at T0 by an independent set of measurements, which are inconsistent with the modeled and known differences between the size ranges, suggesting higher than expected uncertainties in the measurement techniques of 14C. An increase in the non-fossil organic carbon (OC) fraction (fCNFOC) by 0.10–0.15 was observed for both sets of filters during periods with enhanced wildfire activity in comparison to periods when fires were suppressed by rain, which is consistent with the wildfire impacts estimated with other methods. Model results show that the relatively high fraction of non-fossil carbon found in Mexico City seems to arise from the combination of regional biogenic SOA, biomass burning OA, as well as non-fossil urban OA. Similar spatial and temporal variations for fCNFOC are predicted between the urban vs. suburban sites, and high-fire vs. low-fire periods. The absolute modeled values of fCNFOC are consistent with the PM10 dataset but lower than the PM1 filters. Resolving the 14C measurement discrepancies is necessary for further progress in model evaluation. The model simulations that included secondary organic aerosol (SOA) formation from semi-volatile and intermediate volatility (S/IVOC) vapors showed better skill in explaining both total OA mass and fCNFOC compared to simulations which only included SOA from VOCs. Urban sources of modern carbon are important in reducing or closing the gap between model and measurements, even though they are often neglected on the interpretation of 14C datasets. The fCNF of urban POA and SOA precursors is an important parameter that needs to be better constrained by measurements. Performing faster (≤3 h) 14C measurements in future campaigns is critical to further progress in this area. To our knowledge this is the first time that radiocarbon measurements are used together with aerosol mass spectrometer (AMS) organic components to assess the performance of a regional model for organic aerosols.
Modelling burned area in Africa
Authors: Lehsten V. , Harmand P. , Palumbo I. , Arneth A.
Published: June 2010

Abstract. The simulation of current and projected wildfires is crucial for predicting vegetation as well as pyrogenic emissions in the African continent. This study uses a data-driven approach to parameterize burned area models applicable to dynamic vegetation models (DVMs) and global circulation models (GCMs). Therefore we restricted our analysis to variables for which either projections based on climate scenarios are available, or which are calculated by DVMs and the spatial scale to one degree spatial resolution, a common scale for DVMs as well as GCMs. We used 9 years of data (2000–2008) for the variables tree and herb cover, precipitation over the last dry season, wet season and averaged over the last 2 years, a fire-danger index (the Nesterov index), population density and an annual proportion of area burned derived from the MODIS MCD45A1 product. Since the effect of fires on vegetation depends strongly on burning conditions, the timing of wildfires is of high interest too. We related the seasonal occurrence of wildfires to the Nesterov index and found a lognormal relationship with a maximum at a value of 104. We parameterized two generalized linear models, one with the full variable set (model I) and one (model II) considering only climate variables. All introduced variables resulted in an increase in model performance. Model I correctly predicts the spatial distribution and extent of fire prone areas though the total variability is underrepresented. Model II has a much lower performance in both aspects (correlation coefficient of predicted and observed ratio of burned area: 0.71 model I and 0.58 model II). An application of the models with simulated climate data ranging from 1980 to 2060 resulted in a strong decrease of burned area of ca. 20–25%. Since wildfires are an integral part of land use practices in Africa, this indicates a high loss in areas favourable for food production.
Native Dreissena freshwater mussels in the Balkans: in and out of ancient lakes
Authors: Wilke T. , Schultheiß R. , Albrecht C. , Bornmann N. , Trajanovski S. , Kevrekidis T.
Published: June 2010

Abstract. The Balkans is a biogeographically highly diverse region and a worldwide hotspot of endemic freshwater diversity. A substantial part of this diversity is attributed to well recognized and potential ancient lakes in its southwestern part. Despite considerable research efforts, faunal relationships among those lakes are, however, not well understood. Therefore, genetic information from native representatives of the mussel genus Dreissena is used here to test the biogeographical zonation of the Southwestern Balkans, to relate demographic changes to environmental changes, to assess the degree of eco-insularity, to reconstruct their evolutionary history, and to explore the potential of native taxa for becoming invasive. Phylogeographical and population genetic analyses indicate that most populations studied belong to two native species: D. presbensis (incl. the distinct genetic subgroup from Lake Ohrid, D. ''stankovici'') and D. blanci. In addition, the first confirmed record of invasive D. polymorpha in the Southwestern Balkan is presented. The distribution of native Dreissena spp. is largely in concordance with the biogeographical zonations previously proposed based on fish data. Disagreement, however, consists regarding the assignment of the ancient lakes in the area to biogeographical regions. The data for Lake Ohrid are not conclusive. For Lake Prespa, however, a closer biogeographical connection to lakes of the Vardar region and possibly the Northern Ionian region is suggested. While reconstructing the evolutionary histories of Dreissena spp., signs of major demographic and spatial expansions were found. They started some 320 000–300 000 years ago in D. ''stankovici'', some 160 000–140 000 years ago in D. blanci, and some 110 000–70 000 years ago in D. presbensis. These time frames are discussed within the context of available paleogeological data for lakes Ohrid and Prespa. It is suggested that regional environmental changes may have had pronounced effects on the population histories of native Dreissena spp., though the high buffer capacity of Lake Ohrid may have mitigated these effects in D. ''stankovici''. In addition, local events acting upon individual lakes very likely had considerable effects on the demographic histories of Dreissena spp. as well. The observed patterns of immigration and emigration in and out of ancient lakes may suggest that limited gene flow supported the survival of small isolated subpopulations, while eco-insularity may have prevented excessive hybridization and sympatry of closely related taxa. As for the potential invasiveness of native Dreissena spp., the significant spatial expansions inferred are not human-mediated and all taxa still appear to be restricted to their native ranges. Of concern, however, is that D. presbensis and D. blanci today also occur in artificial water bodies, and that invasive D. polymorpha has reached the area.
Clouds and the Faint Young Sun Paradox
Authors: Goldblatt C. , Zahnle K. J.
Published: June 2010

Abstract. We investigate the role which clouds could play in resolving the Faint Young Sun Paradox (FYSP). Lower solar luminosity in the past means that less energy was absorbed on Earth (a forcing of -50 W m−2 during the late Archean), but geological evidence points to the Earth being at least as warm as it is today, with only very occasional glaciations. We perform radiative calculations on a single global mean atmospheric column. We select a nominal set of three layered, randomly overlapping clouds, which are both consistent with observed cloud climatologies and reproduce the observed global mean energy budget of Earth. By varying the fraction, thickness, height and particle size of these clouds we conduct a wide exploration of how changed clouds could affect climate, thus constraining how clouds could contribute to resolving the FYSP. Low clouds reflect sunlight but have little greenhouse effect. Removing them entirely gives a forcing of +25 W m−2 whilst more modest reduction in their efficacy gives a forcing of +10 to +15 W m−2. For high clouds, the greenhouse effect dominates. It is possible to generate +50 W m−2 forcing from enhancing these, but this requires making them 3.5 times thicker and 14 K colder than the standard high cloud in our nominal set and expanding their coverage to 100% of the sky. Such changes are not credible. More plausible changes would generate no more that +15 W m−2 forcing. Thus neither fewer low clouds nor more high clouds can provide enough forcing to resolve the FYSP. Decreased surface albedo can contribute no more than +5 W m−2 forcing. Some models which have been applied to the FYSP do not include clouds at all. These overestimate the forcing due to increased CO2 by 20 to 25% when pCO2 is 0.01 to 0.1 bar.
Hazard estimates for El Chichón volcano, Chiapas, México: a statistical approach for complex eruptive histories
Authors: Mendoza-Rosas A. T. , De la Cruz-Reyna S.
Published: June 2010

Abstract. The El Chichón volcano (Chiapas, México) most recent eruption occurred in 1982 causing the worst volcanic disaster in the recorded history of Mexico. Prior to the eruption, El Chichón volcano was not considered a very hazardous volcano, a perception mostly caused by the low eruption rate of the past eruptions. The correct assessment of volcanic hazard is the first step to prevent a disaster. In this paper, we analyze two periods of the reported eruptive history of El Chichón volcano during the Holocene, searching for the eruption rates of different VEI magnitude categories and testing their time dependence. One period accounting the eruptions of the last 3707 years before the last eruption (BLE) is assumed to be complete, with no missing relevant events. More scarce information of a period extending to 7772 years BLE is then added. We then apply the Non-Homogeneous Generalized Pareto-Poisson Process (NHGPPP), and the Mixture of Exponentials Distribution (MOED) methods to estimate the volcanic hazard of El Chichón considering both periods. The results are compared with the probabilities obtained from the homogeneous Poisson and Weibull distributions. In this case the MOED and the Weibull distribution are rather insensitive to the inclusion of the extended period. In contrast, the NHGPPP is strongly influenced by the extended period.
Operational flood management under large-scale extreme conditions, using the example of the Middle Elbe
Authors: Kron A. , Nestmann F. , Schlüter I. , Schädler G. , Kottmeier C. , Helms M. , Mikovec R. , Ihringer J. , Musall M. , Oberle P. , Saucke U. , Bieberstein A. , Daňhelka J. , Krejčí J.
Published: June 2010

Abstract. In addition to precautionary or technical flood protection measures, short-term strategies of the operational management, i.e. the initiation and co-ordination of preventive measures during and/or before a flood event are crucially for the reduction of the flood damages. This applies especially for extreme flood events. These events are rare, but may cause a protection measure to be overtopped or even to fail and be destroyed. In such extreme cases, reliable decisions must be made and emergency measures need to be carried out to prevent even larger damages from occurring. Based on improved methods for meteorological and hydrological modelling a range of (physically based) extreme flood scenarios can be derived from historical events by modification of air temperature and humidity, shifting of weather fields and recombination of flood relevant event characteristics. By coupling the large scale models with hydraulic and geotechnical models, the whole flood-process-chain can be analysed right down to the local scale. With the developed GIS-based tools for hydraulic modelling FlowGIS and the Dike-Information-System, (IS-dikes) it is possible to quantify the endangering shortly before or even during a flood event, so the decision makers can evaluate possible options for action in operational mode.
Detection of local site conditions influencing earthquake shaking and secondary effects in Southwest-Haiti using remote sensing and GIS-methods
Authors: Theilen-Willige B.
Published: June 2010

Abstract. The potential contribution of remote sensing and GIS techniques to earthquake hazard analysis was investigated in SW-Haiti in order to improve the systematic, standardized inventory of those areas that are more susceptible to earthquake ground motions or to earthquake related secondary effects such as landslides, liquefaction, soil amplifications, compaction or even tsunami-waves. Geophysical, topographical, geological data and satellite images were collected, processed, and integrated into a spatial database using Geoinformation Systems (GIS) and image processing techniques. The GIS integrated evaluation of satellite imageries, of digital topographic data and of various open-source geodata can contribute to the acquisition of those specific tectonic, geomorphologic/topographic settings influencing local site conditions in Haiti and, thus, to a first data base stock. Using the weighted overlay techniques in GIS susceptibility maps were produced indicating areas where causal factors influencing surface-near earthquake shock occur aggregated and interfering each other and, thus, rise the susceptibility to soil amplification. This approach was used as well to create landslide and flooding susceptibility maps.
Basics of Statistical Analysis
Authors: Thomson Diane M.
Published: June 2010

The goal of this appendix is to introduce basic methods in graphing and data analysis and explore some fundamental concepts in statistical reasoning. Three examples of data‐analysis problems relevant to molecular biology are used to illustrate methods covered in a first statistics course, including the two‐sample t test, simple linear regression, and chi square tests for goodness of fit and contingency table hypotheses. The appendix also explores the selection and interpretation of appropriate summary graphs for these analyses, including the use of error bar plots, scatterplots, and bar charts. In addition, a number of key terms and concepts are introduced and explained in the context of the three example problems, including summary statistics, sampling variation, the standard error, null hypothesis testing, the use of test statistics, and the interpretation of p values. Curr. Protoc. Essential Lab. Tech. 3:A.4B.1‐A.4B.22. © 2010 by John Wiley & Sons, Inc.
A Societal Cost of Obesity in Terms of Automobile Fuel Consumption
Authors: Jacobson Sheldon H. , King Douglas M.
Published: June 2010

Growing obesity rates in the United States increase fuel consumption by adding passenger weight to vehicles, demonstrating a link between these two significant socioeconomic issues. This article quantifies several estimates for the annual amount of fuel consumed by noncommercial passenger highway vehicles (i.e., cars and light trucks) in the United States that can be attributed to passenger overweight and obesity. Using a previously published mathematical model, it is estimated that up to one billion gallons of fuel or more are consumed each year due to passenger weight that can be attributed to overweight and obesity, or up to 0.8% of the fuel consumed by cars and light trucks each year. Estimates are generated based on the increase in average weight in the US population over historical time periods, and by direct estimation of the average weight that can be attributed to overweight and obesity in the US population. From an environmental perspective, this additional fuel consumption has the effect of up to 20 billion pounds or more of carbon dioxide emissions, up to 0.5% of such emissions produced in the transportation sector.
Age Replacement Policies
Authors: Ebrahimi Nader
Published: June 2010

Maintenance policies are followed to reduce the incidence of unit failure or to return a failed unit to the operating state. This article concentrates on a particular maintenance policy referred to as an age replacement policy. Under this policy, a unit is replaced upon failure or at a specified age whichever comes first. We develop some of its desirable properties and obtain an optimal age replacement policy. We also define a multivariate version of this policy and give its properties.
Aging, Characterization, and Stochastic Ordering
Authors: Belzunce Félix , Shaked Moshe
Published: June 2010

In this article, we list a number of results that characterize various aging and antiaging notions in terms of stochastic comparisons of related random variables. The random variables that are used in the comparisons are the corresponding residual lives or the corresponding asymptotic equilibrium ages. The aging notions that are studied are the increasing failure rate (IFR), the increasing failure rate average (IFRA), the new better than used (NBU), the decreasing mean residual life (DMRL), as well as other related notions; the corresponding antiaging notions are also characterized in this article. The characterizations are by means of the ordinary stochastic order  ≤ 
st
, of the hazard rate stochastic order  ≤ 
hr
, of the dispersive stochastic order  ≤ 
disp
, of the location‐independent riskier stochastic order  ≤ 
lir
, of the excess wealth stochastic order  ≤ 
ew
, of the increasing convex and the increasing concave stochastic orders  ≤ 
icx
and  ≤ 
icv
, of the Laplace transform stochastic order  ≤ 
Lt
, of the likelihood ratio stochastic order  ≤ 
lr
, as well as by means of other related stochastic orders.
Benders Decomposition
Authors: Taşkin Zeki Caner
Published: June 2010

Benders decomposition is a solution method for solving certain large‐scale optimization problems. Instead of considering all decision variables and constraints of a large‐scale problem simultaneously, Benders decomposition partitions the problem into multiple smaller problems. Since computational difficulty of optimization problems increases significantly with the number of variables and constraints, solving these smaller problems iteratively can be more efficient than solving a single large problem. In this article, we first formally describe Benders decomposition. We then briefly describe some extensions and generalizations of Benders decomposition. We conclude our article by illustrating how the decomposition works on a problem encountered in Intensity Modulated Radiation Therapy (IMRT) treatment planning and giving a numerical example.
B
rownian Motion and Queueing Applications
Authors: Yao David D.
Published: June 2010

The objective of this article is to present an elementary introduction to the applications of Brownian motion in queueing theory. We start with an overview of some of the basics of Brownian motion, followed by Donsker's theorem and the Skorohod problem. We then discuss the fluid and diffusion scaling of queueing processes, taking the single‐server GI/GI/1 queue as an example. We illustrate why the limiting regime under the diffusion scaling is a reflected Brownian motion, and how it leads to a diffusion approximation of the original queue model.
Capacity Allocation
Authors: Lariviere Martin A.
Published: June 2010

A capacity allocation mechanism allows a supplier to apportion output among downstream buyers when submitted orders exceed available capacity. Some buyers will not receive their full request. How the allocation mechanism determines who is shorted and the extent of the shortfall affects how buyers order. Consequently, the allocation mechanism can have a significant impact on supply‐chain performance. In this article, we first discuss the role allocation mechanisms have had in practice and then review academic research on allocation mechanisms. We consider both, single‐period models in which today's orders determine today's allocations as well as multiperiod models in which today's sales determine tomorrow's allocations.
Computational Methods for
CTMCs
Authors: Dayar Tuğrul , Stewart William J.
Published: June 2010

This article concerns the computation of stationary and transient distributions of continuous‐time Markov chains (CTMCs). Once the problem has been formulated, it is shown how computational methods for computing stationary distributions of discrete‐time Markov chains can be applied in the continuous‐time case. This is not so for the case of transient distributions, which turns out to be a much more difficult problem in general. Different approaches to computing transient distributions of CTMCs are explored, from the simple and efficient uniformization method, through matrix decomposition and powering techniques, to ordinary differential equation (ODE) solvers. This latter approach is the only one currently available for nonhomogeneous CTMCs. The basic concept is explained using simple Euler methods, but formulae for more advanced and efficient single‐step Runge–Kutta and implicit multistep BDF methods are provided.
Cost‐Effectiveness Analysis, Health‐Care Policy, and Operations Research Models
Authors: Zaric Gregory S.
Published: June 2010

Cost‐effectiveness analysis is often used to formally investigate the trade‐offs between the economic costs and the health consequences of new medical technologies. Starting with Ontario and Australia in the early 1990s, many public sector drug plans began requiring cost‐effectiveness estimates for all new drugs prior to their approval for reimbursement. Owing to the difficulties in obtaining cost‐effectiveness estimates directly from clinical trials, many cost‐effectiveness estimates are obtained using decision‐analytic and Monte Carlo simulation models. In this article, we give a brief overview of cost‐effectiveness analysis in health care; we discuss some of the types of models that are commonly used and we give a description of how cost‐effectiveness analysis is used in health policy decision making in three different jurisdictions.