bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Self-Assembly into One-Dimensional Nanotube Architectures and Exploitation of Their Functions
Authors: Shimizu Toshimi
Published: December 2008

This review article focuses on the self-assembly of amphiphilic molecules into discrete, hollow cylindrical tubular architectures (organic nanotubes). Research on nanotube formation from dumbbell-shaped peptide lipids, 1-O-glucopyranoside and 1-N-glucopyranosylamide lipids, and wedge-shaped bolaamphiphilic glycolipids with carboxylic, amino, or oligoglycine groups at one end has been outlined with their characteristic self-assembly. Finally, recent progress in mass production, dimension control, and novel functions of organic nanotubes are described.
Specific Fragmentation of K-Shell Excited/Ionized Pyridine Derivatives Studied by Electron Impact: 2-Amino-3-methylpyridine and 3-Methylpyridine
Authors: Okada Kazumasa , Sakai Masamichi , Ohno Keiichi
Published: December 2008

Fragmentation of 2-amino-3-methylpyridine has been investigated by electron impact in the carbon and nitrogen K-shell excitation regions with a comparison to that of 3-methylpyridine. Fragment ions were analyzed with a quadrupole mass spectrometer. Yields of the NCNH2+ and C5H3+/C4HN+ fragment ions characteristically increase at the N 1s edge when compared to the C 1s excitation/ionization and valence ionization. This observation indicates that a valence electron forming the C–N bond in the pyridine ring is preferentially released through an Auger electron emission at the N 1s edge. The fragment ions produced via a hydrogen atom shift were observed as well.
High Efficiencies for Singlet Oxygen Generation of Fullerenes and Their Phototoxicity
Authors: Iizumi Yoko , Okazaki Toshiya , Zhang Minfang , Yudasaka Masako , Iijima Sumio
Published: December 2008

Although fullerenes have been known as strong photosensitizers (PS), the quantitative evaluations of their activities have been insufficient, especially in water. We measured the near-infrared (NIR) emission from the singlet oxygen (1O2) produced by C60 and C70 dissolved in water using dispersants of γ-cyclodextrin (γ-CD) or poly(vinylpyrrolidone) (PVP), and estimated the 1O2 generation efficiencies. The obtained results show that C60 and C70 can generate 1O2 with 2–3 times higher efficiencies than the well-known PS, rose bengal (RB), and the 1O2 generation efficiencies depends on the dispersants. Phototoxicity of C60 and C70 were also examined by using rat fibroblast cell line (5RP7). The cell viabilities after irradiations were consistent with the corresponding 1O2 generation efficiencies. Our results that fullerenes have high 1O2 generation efficiencies assure the potential applications of fullerenes as PS for photodynamic therapy (PDT).
Transformation of a Modest Luminescent Chemosensor into a Light-Up Probe: The Overload Displacement Approach
Authors: Schmittel Michael , Lin Hengwei
Published: December 2008

As a proof of principle for the overload displacement strategy a luminescent ruthenium(II) azacrown ether phenanthroline with restrained sensoric properties has been converted into a light-up chemosensor for lead(II) ions by overloading the system with copper(II) ions.
An Efficient Identification Method of a Specific Binding Protein for a Bioactive Compound Using On-Bead Digestion and Mass Spectrometry
Authors: Sakai Mitsuru , Furuya Minoru , Endo Hiroko , Yamaoka Kazuyoshi , Kondo Shiro , Koike Tohru
Published: December 2008

Affinity chromatography is widely utilized as a tool in biomedical research and biotechnology. This purification method provides increased sensitivity for various kinds of analyses, such as mass spectrometry. This report describes a protocol to identify a specific binding protein for a bioactive compound (BAC) using BAC-affinity beads and nanoflow liquid chromatography tandem mass spectrometry (nano-LC/MS/MS). After the target protein was digested directly on the affinity beads, the obtained peptide fragments were determined by MS analysis. The binding-specificity was shown by a competition experiment using beads lacking bound BAC. In this study, we describe two examples for benzenesulfonamide- and methotrexate-binding proteins.
Anti-Inflammatory Polyoxygenated Steroids from the Soft Coral Sinularia sp.
Authors: Su Jui-Hsin , Lo Ching-Li , Lu Yi , Wen Zhi-Hong , Huang Chiung-Yao , Dai Chang-Feng , Sheu Jyh-Horng
Published: December 2008

Four new polyhydroxylated steroids (1–4) were isolated from a Formosan soft coral Sinularia sp. The structures of these metabolites were determined on the basis of spectroscopic (IR, MS, and 1D and 2D NMR) analyses. Among these metabolites, 3 and 4 are rarely found marine steroids with a C-9/C-10 double bond. Compounds 1 and 2 have shown significant inhibition of the accumulation of the pro-inflammatory COX-2 protein of LPS-stimulated RAW264.7 macrophage cells at 10 μM.
1- and 3-Nitreno-2-naphthylcarbenes. A Combined Experimental and Computational Study
Authors: Tomioka Hideo , Nakane Norio , Tatsugi Jiro
Published: December 2008

The structures, energies, and thermal stabilities of E and Z isomers of a singlet, a triplet, and a quintet states of naphthalene bearing nitrene and carbene units on adjacent (1,2- and 3,2-) positions were examined by DFT methods. For both 1,2- and 3,2-isomers, singlet quinoidal diradicals were predicted to be the ground state with the corresponding triplet state lying slightly higher in energy. The quintet state of the 1,2-isomer was found to lie approximately 30 kcal mol−1 (1 kcal = 4.184 kJ) above the ground state, while that of the 3,2-isomer was predicted to lie only 9 kcal mol−1 above the ground state. This difference is discussed in terms of loss of energy due to aromaticity between the two isomers. Thermal stability of the ground state in terms of ring-opening and -closure reactions indicated that both isomers prefer to decay by the latter process forming naphtho[b]azetes. Attempts to generate and characterize the ground state quionoidal diradical by matrix IR spectroscopic methods in Ar at low temperature all resulted in the detection of the azete.
New Polyoxygenated Briaranes from Octocorals Briareum excavatum and Ellisella robusta
Authors: Hwang Tsong-Long , Lin Mei-Ru , Tsai Wei-Tse , Yeh Hsiao-Chien , Hu Wan-Ping , Sheu Jyh-Horng , Sung Ping-Jyun
Published: December 2008

Six new polyoxygenated briarane-type diterpenoids, briaexcavatins Q–T (1–4) and robustolides J (5) and K (6), were isolated from a cultured octocoral Briareum excavatum and a sea whip gorgonian coral Ellisella robusta, respectively. The structures of briaranes 1–6 were established by spectroscopic methods. Briarane 3 exhibited weak cytotoxicity toward CCRF-CEM tumor cells and briaranes 5 and 6 displayed inhibitory effects on superoxide anion generation by human neutrophils.
Effect of Bulk Natural Convection on Chemical Processes Studied in a Tight Polymer Gel Reactor Composed of Polysaccharide Network and a Large Excess of Water
Authors: Ueno Hirohito , Gokan Norihiko , Nakano Yoshiharu , Kaneko Masao
Published: December 2008

The effect of bulk natural convection on various chemical processes was investigated in a tight polysaccharide gel reactor composed of a few percent polysaccharide and excess water. It was elucidated that molecular self-diffusion coefficient (D cm2 s−1) in the gel is the same as in liquid water, but bulk natural convection is entirely prohibited making the molecular transport in these gels remarkably slower than in liquid water. Three-dimensional (3D) diffusion of Ru(bpy)32+ in a tight 0.125 wt % agarose gel took place only by molecular self-diffusion since bulk natural convection is prohibited, and the diffusion length agreed well with the theoretical 3-dimensional (3-D) self-diffusion length calculated from D. 2D diffusion of thionine in a polysaccharide gel also agreed well with the theoretical 2-D self-diffusion length showing also the absence of bulk natural convection. The chemical processes in the tight gel reactor in relevance to natural convection effects are discussed in terms of the time scale of the chemical process and the corresponding self-diffusion length of the reactants. For short time scale processes (ns to s) such as photochemical and electrochemical reactions, the process was not affected by bulk natural convection, but for a longer time scale (0.1 to 10 h) the effect of bulk natural convection was large.
Fabrication of Conjugated Polymer Hybrid Thin Films with Radially Oriented Aluminosilicate Nanofibers by Spin-Assembly
Authors: Jiravanichanun Nattha , Yamamoto Kazuya , Yonemura Hiroaki , Yamada Sunao , Otsuka Hideyuki , Takahara Atsushi
Published: December 2008

Multilayer hybrid films of imogolite nanofibers and water-soluble poly(p-phenylene) (WS-PPP) were prepared by two assembly methods. Layer-by-layer (LBL) assembly and spin-assembly were applied to fabricate the hybrid films. The deposited amount of WS-PPP per thickness was not significantly different between the two methods. However, the spin-assembly method gave significant orientation of imogolite nanofibers aligned in the radial direction, while imogolite nanofibers were randomly networked in the LBL film. The results suggested that lyotropic mesophase of imogolite and centrifugal and shear forces influenced a self-assembly of imogolite fibers oriented in a force-inducing direction.
Students' conceptions of constructivist learning in different programme years and different learning environments
Authors: Loyens Sofie M. M. , Rikers Remy M. J. P. , Schmidt Henk G.
Published: December 2008

Background Constructivist views of learning have brought conceptions of learning to attention again. Conceptions are considered important determinants of effective learning. Students can differ in their conceptions depending on their educational experience.

Aims The present study investigated students' conceptions of constructivist learning. Do students with greater experience in their academic programme differ in their conceptions of constructivist learning compared to students with less experience/ In addition, to what extent are conceptions of constructivist learning different in a conventional, lecture‐based curriculum compared to a constructivist, problem‐based learning curriculum/

SamplesThree groups (i.e. first‐year, second‐year, and third‐year students) in two different curricula (i.e. conventional, lecture‐based and constructivist, problem‐based) were tested.

Methods A cross‐sectional design was used. Students' conceptions of constructivist activities (i.e. knowledge construction, cooperative learning, self‐regulation, use of authentic problems, self‐perceived inability to learn, and motivation to learn) were measured by a questionnaire. Data were analyzed using a two‐way multivariate analysis of variance (MANOVA).

Results A significant difference in questionnaire's scores between year 1 and year 2 (but not between year 2 and 3) was found with respect to conceptions about knowledge construction, self‐regulation, and the use of authentic problems, but not for cooperative learning and motivation to learn. For self‐perceived inability, an interaction effect was found. Furthermore, results showed significant differences between both curriculum groups on all dependent measures.

Conclusions Differences in conceptions can be perceived between students who enter a new learning programme (i.e. higher education) and students who already have one year of experience in higher education. Among students with more than one year of educational experience, differences disappear. Furthermore, this study shows that the learning environment can make a difference with respect to students' conceptions of constructivist learning activities.
Associations among false belief understanding, counterfactual reasoning, and executive function
Authors: Guajardo Nicole R. , Parker Jessica , Turley‐Ames Kandi
Published: December 2008

The primary purposes of the present study were to clarify previous work on the association between counterfactual thinking and false belief performance to determine (1) whether these two variables are related and (2) if so, whether executive function skills mediate the relationship. A total of 92 3‐, 4‐, and 5‐year‐olds completed false belief, counterfactual, working memory, representational flexibility, and language measures. Counterfactual reasoning accounted for limited unique variance in false belief. Both working memory and representational flexibility partially mediated the relationship between counterfactual and false belief. Children, like adults, also generated various types of counterfactual statements to differing degrees. Results demonstrated the importance of language and executive function for both counterfactual and false belief. Implications are discussed.
Patterns of problem‐solving in children's literacy and arithmetic
Authors: Farrington‐Flint Lee , Vanuxem‐Cotterill Sophie , Stiller James
Published: December 2008

Patterns of problem‐solving among 5‐to‐7 year‐olds' were examined on a range of literacy (reading and spelling) and arithmetic‐based (addition and subtraction) problem‐solving tasks using verbal self‐reports to monitor strategy choice. The results showed higher levels of variability in the children's strategy choice across Years 1 and 2 on the arithmetic (addition and subtraction) than literacy‐based tasks (reading and spelling). However, across all four tasks, the children showed a tendency to move from less sophisticated procedural‐based strategies, which included phonological strategies for reading and spelling and counting‐all and finger modelling for addition and subtraction, to more efficient retrieval methods from Years 1 to 2. Distinct patterns in children's problem‐solving skill were identified on the literacy and arithmetic tasks using two separate cluster analyses. There was a strong association between these two profiles showing that those children with more advanced problem‐solving skills on the arithmetic tasks also showed more advanced profiles on the literacy tasks. The results highlight how different‐aged children show flexibility in their use of problem‐solving strategies across literacy and arithmetical contexts and reinforce the importance of studying variations in children's problem‐solving skill across different educational contexts.
Population Dynamics of Broadleaf Weeds in Turfgrass as Influenced by Chemical and Biological Control Methods
Authors: Abu-Dieyeh Mohammed H. , Watson Alan K.
Published: December 2008

A 3-yr field study was conducted to determine the effect of a biological control agent,Sclerotinia minorJagger, and a common herbicide, Killex, on the population dynamics of dandelion and other broadleaf species and on the dandelion seed bank. Treatments were applied as one spring, one early autumn, or a spring plus an early autumn treatment per year. The response of the dandelion population to a spring herbicide treatment was similar to two applications per year (spring and early autumn). Significantly less dandelion control occurred after the first early autumn application of the herbicide. Two weeks after application, spring or early autumn treatments withS. minorwere equally effective in suppressing dandelions. In the second year of the two applications per year ofS. minortreatment, weed control was equivalent to the herbicide. By the third year of the one spring application ofS. minor, weed control was equivalent to the herbicide. Generally over the study period, the early autumn application ofS. minorwas less effective than the spring or the spring and early autumn applications. TheS. minortreatments significantly reduced the dandelion seed bank, and this effect was not significantly different from the Killex herbicide treatment. The rate, frequency, and seasonal timing of application had no effect on the dandelion seed-bank size, but terminating the application would gradually replenish the seed bank. Populations of white clover, broadleaf plantain, birdsfoot trefoil, and common ragweed were similarly suppressed by either theS. minoror the herbicide treatments. Yellow woodsorrel significantly increased after 1 yr of herbicide treatment compared with theS. minorand untreated control treatments, indicating a possible weed species shift. Turf quality was improved because of the herbicide andS. minortreatments, but grass injury and smooth crabgrass invasion were recorded in 17% of herbicide-treated plots.
Private finance for the delivery of school projects in England
Authors: Aritua B. , Smith N. J. , Athiyo R.
Published: December 2008

This paper analyses the use of the private finance initiative (PFI) approach to deliver school projects in England. The findings are based on case-study research in the Building Schools for the Future scheme (BSF), the largest single capital investment in 50 years to rebuild and renew all of England’s secondary schools. Up to half of the school infrastructure is to be procured by PFI contracts. A major concern has been the high cost associated with PFI procurement and any subsequent changes to scope. Furthermore, in some cases PFI-funded schools have been closed soon after completion; at great cost to the public sector. The aim of this research was therefore to understand the underlying reasons for these problems. The main conclusion is that the difficulties in BSF arise from not sorting out strategic issues and instituting appropriate organisational frameworks before engaging the private sector. The result of this is a lack of clarity about the long-term needs and end user aspirations. A brief outline of current programme management methods is given and it is suggested that this might be integral to the successful delivery of schools using private finance. A clear strategic vision that cascades into projects via programmes will ensure that the school infrastructure is appropriate for the anticipated strategic benefits and is aligned to the overall service delivery ambitions.
Public–private delivery of urban water services in Africa
Authors: Kayaga S.
Published: December 2008

The period between 1990 and 1997 saw a record growth in the number of public–private partnerships (PPPs) for provision of water/sewerage services in developing countries. Nonetheless, PPPs have not fared well in sub-Saharan Africa, which accounted for 80% of the PPP contracts that attracted disputes or were cancelled between 1990 and 2004. Since the 1980s, management contracts between international water operators and utilities in Africa have been promoted by the World Bank and other multi-international agencies as a model that could boost management capacity in utilities of developing countries and lead to improved effectiveness and efficiency. The present study draws upon empirical data from Kampala, Uganda and uses it as a case study to show that, on the whole, these expectations were not fulfilled. It is demonstrated that the performance improvements of the National Water and Sewerage Corporation, the utility in Kampala, were not as high as expected when it was twice managed by different international operators. On the other hand, the corporation has made impressive performance improvements under the current public management model. Conclusions have been drawn from the case study on what are the drivers of performance improvement in the water utilities of developing countries.
Role of export credit agencies in PFI/PPP projects
Authors: Wamuziri S. , Jiang M.
Published: December 2008

The paper presents the results of an investigation into the role of export credit agencies (ECAs) in international private-finance initiative/public–private partnership (PFI/PPP) projects. The research was based on an assessment of published literature and a study of relevant official reports. The use of PFI/PPP procurement to deliver essential infrastructure continues to grow worldwide. In developing countries, funding raised locally through taxation, the money markets and official development assistance is inadequate to meet the required needs. PFI/PPP projects with foreign private participation provide a vital contribution to the acceleration of economic growth and provision of essential services and infrastructure. It is demonstrated in this paper that ECAs play a number of key multiple roles in international PFI/PPP projects. First, the role of ECAs can be as lenders. ECA loans can be offered to exporters, investors or directly to the special-purpose vehicle. ECAs also play the role of insurers/guarantors. ECAs are diversified in country risks and therefore best placed to cover political and non-commercial risks. They can provide cover for non-commercial risks which include: currency inconvertibility and transfer restrictions, expropriation, war and civil disturbance or breach of contract, etc. The professional advisory role includes arranging project finance and a disputes resolution service. ECAs play key multiple roles in the realisation of international PFI/PPP projects. They are clearly central to efficient risk management in such projects and for attracting foreign direct investment into infrastructure in developing countries.
PPP in urban water: lessons from Yerevan, Armenia
Authors: Mugabi J. , Marin P.
Published: December 2008

Recent literature on public–private partnerships (PPPs) in urban water supply and sanitation (WSS) services tends to concentrate on distressed projects, especially when high-profile concessions are cancelled. Successful projects get comparatively little attention, contributing to the impression that water PPPs do not work. The management contract in Yerevan, Armenia is one example in which private sector participation in WSS service provision has brought benefits to the population, and has been endorsed satisfactorily by the government and national stakeholders. This paper discusses the process and outcomes of Yerevan’s management contract (2000–2005), and highlights important lessons for policy-makers and reformers. Based on available data, the authors find evidence of improvements in the quality of services, collections, and energy efficiency, but only modest improvements in technical efficiency. The case study holds valuable lessons for other developing countries, as some challenges had to be faced during implementation. It shows ultimately that, to realise benefits from a management contract, both parties must be willing to make it work, and build over time a true partnership.
Temperature as a toxicity identification evaluation tool for pyrethroid insecticides: Toxicokinetic confirmation
Authors: Harwood Amanda D. , You Jing , Lydy Michael J.
Published: December 2008

Toxicity identification evaluation (TIE) methods can be used to identify toxic compounds in environmental samples using a variety of laboratory techniques. Whereas TIEs exist for nonpolar organics, relatively few methods are established for individual contaminant classes. Toxicity identification evaluations have shown pesticides to be the cause of toxicity in agricultural waters and effluents, and more recent studies have shown that the insecticide class of concern is pyrethroids. The primary objectives of the present study were to confirm a temperature TIE model and mechanistically explain these trends. This was achieved by comparing the relative toxicity and influence of temperature (13 vs 23°C) on Chironomus dilutus exposed to four insecticides, including two pyrethroids, an organophosphate, and an organochlorine, and then explaining these changes using toxicokinetics. A 10°C temperature decrease increased the toxicity of pyrethroids and DDT but decreased the toxicity of chlorpyrifos. The decrease in chlorpyrifos toxicity was driven primarily by the reduction of the formation of more toxic products via decreased biotransformation. The increase in DDT toxicity, in contrast, can be attributed to increased nerve sensitivity at 13 versus 23°C. The pyrethroid toxicity change, however, resulted from a combination of increased accumulation of parent compound and increased nerve sensitivity, exacerbating the toxicity of pyrethroids at 13°C. These trends also held true in sediment exposures with chlorpyrifos and permethrin, indicating that water-only exposures were adequate substitutes for examining this mechanism.
Optimal Insurance and Reinsurance Policies in the Risk Process
Authors: Golubin A.Y.
Published: December 2008

The paper examines a classical risk model where both insurance and reinsurance policies are chosen by the insurer in order to minimize the expected maximal loss. We show that the optimal control problem reduces to a static case. We found that the optimal reinsurance is excess of loss reinsurance and describe the set optimal insurance policies. Such a policy providing the minimal variance of the risk left with insured turns out to be a combination of stop loss and deductible policies. The results are illustrated by two numerical examples.
Dividend Moments in the Dual Risk Model: Exact and Approximate Approaches
Authors: Cheung Eric C.K. , Drekic Steve
Published: December 2008

In the classical compound Poisson risk model, it is assumed that a company (typically an insurance company) receives premium at a constant rate and pays incurred claims until ruin occurs. In contrast, for certain companies (typically those focusing on invention), it might be more appropriate to assume expenses are paid at a fixed rate and occasional random income is earned. In such cases, the surplus process of the company can be modelled as a dual of the classical compound Poisson model, as described in Avanzi et al. (2007). Assuming further that a barrier strategy is applied to such a model (i.e., any overshoot beyond a fixed level caused by an upward jump is paid out as a dividend until ruin occurs), we are able to derive integro-differential equations for the moments of the total discounted dividends as well as the Laplace transform of the time of ruin. These integro-differential equations can be solved explicitly assuming the jump size distribution has a rational Laplace transform. We also propose a discrete-time analogue of the continuous-time dual model and show that the corresponding quantities can be solved for explicitly leaving the discrete jump size distribution arbitrary. While the discrete-time model can be considered as a stand-alone model, it can also serve as an approximation to the continuous-time model. Finally, we consider a generalization of the so-called Dickson-Waters modification in optimal dividends problems by maximizing the difference between the expected value of discounted dividends and the present value of a fixed penalty applied at the time of ruin.
Optimal Investment and Bounded Ruin Probability: Constant Portfolio Strategies and Mean-variance Analysis
Authors: Korn Ralf , Wiese Anke
Published: December 2008

We study the continuous-time portfolio optimization problem of an insurer. The wealth of the insurer is given by a classical risk process plus gains from trading in a risky asset, modelled by a geometric Brownian motion. The insurer is not only interested in maximizing the expected utility of wealth but is also concerned about the ruin probability. We thus investigate the problem of optimizing the expected utility for a bounded ruin probability. The corresponding optimal strategy in various special classes of possible investment strategies will be calculated. For means of comparison we also calculate the related mean-variance optimal strategies.
Pareto Optimality and Equilibrium in an Insurance Market
Authors: Golubin Alexey Y.
Published: December 2008

The concept of economic equilibrium under uncertainty is applied to a model of insurance market where, in distinction to the classic Borch’s model of a reinsurance market, risk exchanges are allowed between the insurer and each insured only, not among insureds themselves. Conditions characterizing an equilibrium are found. A variant of the conditions, based on the Pareto optimality notion and involving risk aversion functions of the agents, is derived. An existence theorem is proved. Computation of the market premiums and optimal indemnities is illustrated by an example with exponential utility functions.
Sampling Distributions of Critical Illness Insurance Premium Rates: Breast and Ovarian Cancer
Authors: Lu Li , Macdonald Angus , Waters Howard
Published: December 2008

Evaluating the risk of disorders in long-term insurance often relies on rates of onset estimated from quite small epidemiological studies. These estimates can carry considerable uncertainty, hence so may functions of them, such as a premium rate. In the case of genetic disorders, where it may be required to demonstrate the reliability of genetic information as a risk factor, such uncertainty may be material. Epidemiological studies publish their results in a variety of forms and it is rarely easy to estimate the sampling distribution of a premium rate without access to the original data. We found a large study of breast and ovarian cancer that cited relative risks of breast and ovarian cancer onset, with confidence intervals, in 10-year age groups. We obtained critical illness premium rates and their sampling distributions by parametric bootstrapping, and investigated the effect of possible patterns of sampling correlations. We found that this study provides ample statistical evidence that known BRCA1 or BRCA2 mutations, or a typical family history of breast or ovarian cancer, are reliable risk factors, but the sampling covariances of the relative risks could be important at some ages and terms. Studies that cite only standard errors of parameter estimates erect a small but awkward barrier between the models they describe, and some important actuarial questions.
Credibility for the Chain Ladder Reserving Method
Authors: Gisler Alois , Wüthrich Mario V.
Published: December 2008

We consider the chain ladder reserving method in a Bayesian set up, which allows for combining the information from a specific claims development triangle with the information from a collective. That is, for instance, to consider simultaneously own company specific data and industry-wide data to estimate the own company's claims reserves. We derive Bayesian estimators and credibility estimators within this Bayesian framework. We show that the credibility estimators are exact Bayesian in the case of the exponential dispersion family with its natural conjugate priors. Finally, we make the link to the classical chain ladder method and we show that using non-informative priors we arrive at the classical chain ladder forecasts. However, the estimates for the mean square error of prediction differ in our Bayesian set up from the ones found in the literature. Hence, the paper also throws a new light upon the estimator of the mean square error of prediction of the classical chain ladder forecasts and suggests a new estimator in the chain ladder method.
A Universal Pricing Framework for Guaranteed Minimum Benefits in Variable Annuities
Authors: Bauer Daniel , Kling Alexander , Russ Jochen
Published: December 2008

Variable Annuities with embedded guarantees are very popular in the US market. There exists a great variety of products with both, guaranteed minimum death benefits (GMDB) and guaranteed minimum living benefits (GMLB). Although several approaches for pricing some of the corresponding guarantees have been proposed in the academic literature, there is no general framework in which the existing variety of such guarantees can be priced consistently. The present paper fills this gap by introducing a model, which permits a consistent and extensive analysis of all types of guarantees currently offered within Variable Annuity contracts. Besides a valuation assuming that the policyholder follows a given strategy with respect to surrender and withdrawals, we are able to price the contract under optimal policyholder behavior. Using both, Monte-Carlo methods and a generalization of a finite mesh discretization approach, we find that some guarantees are overpriced, whereas others, e.g. guaranteed annuities within guaranteed minimum income benefits (GMIB), are offered significantly below their risk-neutral value.
Optimal Dividends in the Dual Model with Diffusion
Authors: Avanzi Benjamin , Gerber Hans U.
Published: December 2008

In the dual model, the surplus of a company is a Lévy process with sample paths that are skip-free downwards. In this paper, the aggregate gains process is the sum of a shifted compound Poisson process and an independent Wiener process. By means of Laplace transforms, it is shown how the expectation of the discounted dividends until ruin can be calculated, if a barrier strategy is applied, and how the optimal dividend barrier can be determined. Conditions for optimality are discussed and several numerical illustrations are given. Furthermore, a family of models is analysed where the individual gain amount distribution is rescaled and compensated by a change of the Poisson parameter.
Optimizing alum coagulation for turbidity, organics, and residual Al reductions
Authors: Bérubé D. , Dorea C. C.
Published: December 2008

Increases in residual dissolved Al from alum coagulation associated with low water temperatures should be minimised to avoid problems in the distribution mains and as a precautionary approach to possible health effects of Al. Temperature-controlled jar-tests (0.1 to 17.0°C) were used to evaluate optimisation of a plant using alum coagulation at pH 6.0 followed by activated silicate addition. pH adjustment was assessed during coagulation and flocculation (i.e. before and after activated silicate) in order to control residual Al by precipitation without affecting turbidity and natural organic matter (NOM) reductions. The effects on NOM reduction were marginal until pH 6.4 in all conditions tested. Turbidity reductions by sedimentation considerably worsened when increasing pH, especially at the lowest temperature. Experimental conditions to eliminate this negative effect were found to be by increasing the pH after silicate addition (from the coagulation pH of 6.0 to between 6.1 and 6.3). By pH adjustments after silicate addition, up to 90% decrease in dissolved Al could be obtained at pH ∼6.8 (from 180 to ∼20 μg/L) at low temperatures. At this pH level, however, turbidity reduction reached minimal values (10–20%) while NOM reduction was clearly affected, indicating partial NOM re-dissolution. Slight pH adjustments of coagulation pH (up to 6.1) or flocculation pH (up to 6.3—after silicate addition) promised significant dissolved Al minimization (down to ∼50 μg/L) without compromising turbidity or NOM reductions.
Modeling of biofilm in the water distribution system
Authors: Hu Tai-Lee , Lin Chenfang , Chen Wei-Yu
Published: December 2008

In order to understand the growth of biofilm and to serve as the basis of cleaning the water distribution pipeline, this study used a multi-attachment dynamic model to simulate the growth of microorganisms' attachment to the pipe wall. The model had considered attachment, detachment, and propagating factors. The attachment and detachment factors are divided into “cell to cell” and “cell to substratum”. Factors for biofilm growth included two possibilities, which was “lateral growth” and “vertical growth”. Data set of the biofilm biomass from a laboratory scale water distribution system was measured. The data and the model simulation curves were compared so as to justify the performance of the model.

The results show that several sets of parameters could be identified. From the simulation of biofilm biomass in the pipeline, the microbial growth related with the incubation time. Due to nutrients being restricted, the biomass of biofilm in the water distribution system did not continue to grow and reached a maximum at about Day 40. From the simulation results, it was suggested the time of cleaning the water distribution pipeline be shortened to one or two months.

The model was applied to simulate the tap water biofilm in the pipeline of Kaohsiung city, the second largest in Taiwan with 1.5 million population. The results revealed various levels of risks and the proportionality between the biomass in the water and the growth rate of biofilm. However, most households had the purifying facility of a reverse osmosis system. From the simulation, the facility proved its effectiveness for preventing the intervention of bacteria from the biofilm formation in the distribution pipelines.
Polyvalent fingerprint based molecular surveillance methods for drinking water supply systems
Authors: Henne K. , Kahlisch L. , Draheim J. , Brettar I. , Höfle M. G.
Published: December 2008

Despite the relevance for public health, surveillance of drinking water supply systems (DWSS) in Europe is mainly achieved by cultivation based detection of indicator bacteria. The study presented here demonstrates the use of molecular analysis based on fingerprints of DNA extracted from drinking water bacteria as a valuable monitoring tool of DWSS and was exemplified for a DWWS in Northern Germany. The analysis of the bacterial community of drinking water was performed by a set of 16S rRNA gene based fingerprints, sequence analysis of relevant bands and phylogenetic assignment of the 16S rRNA sequences. We assessed the microflora of drinking water originating from two reservoirs in the Harz Mountains. The taxonomic composition of the bacterial communities from both reservoirs was very different at the species level reflecting the different limnological conditions. Detailed analysis of the seasonal community dynamics of the tap water revealed a significant influence of both source waters on the composition of the microflora and demonstrated the relevance of the raw water microflora for the drinking water reaching the consumer. According to our experience, molecular analysis based on fingerprints of different degrees of resolution can be considered as a valuable monitoring tool of DWSS.
Assessment of Management Techniques to Reduce Woodpecker Damage to Homes
Authors: HARDING EMILY G. , CURTIS PAUL D. , VEHRENCAMP SANDRA L.
Published: December 2008

Abstract: Woodpecker damage to homes and buildings is a widespread and locally severe problem in vertebrate pest control. Woodpeckers may cause an average of $300 (United States currency) in damage to affected houses, resulting in millions of dollars of property damage annually in the United States. However, there is no known, practical, consistently effective technique to prevent woodpecker damage. We tested the effectiveness of 6 woodpecker control techniques available commercially, used anecdotally by homeowners, and recommended by wildlife specialists in different Cooperative Extension publications. These deterrents included Prowler Owls, Irri‐TapeTM, the Bird Pro Sound System, Scare‐Eyes (all manufactured by Bird‐X, Inc., Chicago, IL), suet feeders, and roost boxes. We conducted our study in late spring and autumn during August 2003 through December 2004 in the Town of Ithaca, Tompkins County, New York, USA. We evaluated 16 homes with active woodpecker damage, and visited each house about 3 times per week to determine a rate of new woodpecker holes per day. We then placed a deterrent at the house and monitored the rate of new holes per day. Although none of the deterrents that we tested was completely successful in keeping woodpeckers from creating new holes in house siding, homes where Irri‐Tape was installed exhibited the greatest reduction in woodpecker damage. Avoiding earth‐tone stain and paint colors may be the best long‐term solutions for preventing woodpecker damage in wooded areas. Homeowners should avoid using natural‐colored stains, as brightly painted houses (white, light blue, pastels) were less likely to attract woodpeckers.
Kant i prosvetiteljstvo - moderna ontologija aktuelnosti
Authors: Nikolic Srdjan
Published: December 2008

(nemacki) Von einer Anmerkung Foucault's ?ber die Bedeutung von Kants Auffassung der Aufkl?rung f?r die moderne Philosophie ?berhaupt ausgehend, versuchen wir in diesem Text die Spur des Zusammenhangs zwischen der Frage nach der Aktualit?t der Aufkl?rung und der Moderne bei Kant zu verfolgen. Die Ideen der Freiheit und der Subjektivit?t verstehen wir dabei als unvermeidbar, um das Kantsche aufkl?rerische Projekt und seine Aktualit?t zu verstehen. In der Studie versuchen wir den Blick freizumachen f?r eine spezifische, moderne Auffassung der Aktualit?t, die weitreichende ontologische Folgen hat, besonders wenn es um die Kategorie der (Un-)M?glichkeit geht. Aufgrund der durchgef?hrten Analysen gelangen wir zu der These, dass sich die Antwort auf die Frage nach der Aktualit?t der Aufkl?rung als ein Ansatz im Kampf um die Verwirklichung des Unm?glichen ergibt.
Religious Europe, Russia and Serbia past and present: Arguments of empirical evidence: The case of Russia
Authors: Blagojevic Mirko
Published: December 2008

This article is the sequel to the author's text in the previous issue of the magazine 'Philosophy and Society'. The author discusses the evolution of religious consciousness among the population of Russia and the mutual relationship between society, religion and church describing it as a sort of religious balance. By examining the motion of the balance, the author analyzes the religious situation and the confessional structure of tzarist, soviet and modern Russia. Three types of confessional structure may be postulated during the period in question: a stable confessional structure of pre-revolutionary Russia, a destabilized confessional structure in soviet time, a restabilized structure during the nineties of the previous century, and a new stabilized confessional structure in recent years.
Antibacterial activity of cobalt(II) complexes with some benzimidazole derivatives
Authors: Podunavac-Kuzmanovic S.O. , Leovac V.M. , Cvetkovic D.D.
Published: December 2008

The antibacterial activities of cobalt(II) complexes with two series of benzimidazoles were evaluated in vitro against three Gram-positive bacterial strains (Bacillus cereus, Staphylococcus aureus, and Sarcina lutea) and one Gram-negative isolate (Pseudomonas aeruginosa). The minimum inhibitory concentration was determined for all the complexes. The majority of the investtigated complexes displayed in vitro inhibitory activity against very persistent bacteria. They were found to be more active against Gram-positive than Gram-negative bacteria. It may be concluded that the antibacterial activity of the compounds is related to the cell wall structure of the tested bacteria. Comparing the inhibitory activities of the tested complexes, it was found that the 1-substituted- -2-aminobenzimidazole derivatives were more active than complexes of 1-substituted- 2-amino-5,6-dimethylbenzimidazoles. The effect of chemical structure on the antibacterial activity is discussed.
Quality of life research in patients suffering from tension type headache
Authors: Simic Svetlana , Slankamenac Petar , Kopitovic Aleksandar , Jovin Zita , Banic-Horvat Sofija
Published: December 2008

The tension type headache is the most common headache type, which many men and women suffer from in one period of their life and aggravates business productivity, family and social functioning. Quality of life estimation in patients suffering from tension type headache enables us to get a better insight into the impact of the disease on the patient. The comparison among the quality of life in the patients suffering from tension type headache and the quality of life in the control group subjects has been carried out in a research by applying the QVM questionnaire. The obtained results have shown a significant difference in the quality of life and its sub domains indicating worse quality in the patients suffering from tension type headache.
Morphometric characteristics of Neuropeptide Y immunoreactive neurons of human cortical amygdaloid nucleus
Authors: Malis Milos , Nikolic Valentina , Djulejic Vuk , Opric Dejan , Rasulic Lukas , Puskas Laslo
Published: December 2008

Introduction Cortical amygdaloid nucleus belongs to the corticomedial part of the amygdaloid complex. In this nucleus there are neurons that produce neuropetide Y. This peptide has important roles in sleeping, learning, memory, gastrointestinal regulation, anxiety, epilepsy, alcoholism and depression. Material and methods We investigated morphometric characteristics (numbers of primary dendrites, longer and shorter diameters of cell bodies and maximal radius of dendritic arborization) of NPY immunoreactive neurons of human cortical amygdaloid nucleus on 6 male adult human brains, aged 46 to 77 years, by immunohistochemical avidin-biotin technique. Results Our investigation has shown that in this nucleus there is a moderate number of NPY immunoreactive neurons. 67% of found neurons were nonpyramidal, while 33% were pyramidal. Among the nonpyramidal neurons the dominant groups were multipolar neurons (41% - of which 25% were multipolar irregular, and 16% multipolar oval). Among the pyramidal neurons the dominant groups were the neurons with triangular shape of cell body (21%). All found NPY immunoreactive neurons (pyramidal and nonpyramidal altogether) had intervals of values of numbers of primary dendrites 2 to 6, longer diameters of cell bodies 13 to 38 ?m, shorter diameters of cell bodies 9 to 20 ?m and maximal radius of dendritic arborization 50 to 340 ?m. More than a half of investigated neurons (57%) had 3 primary dendrites. Discussion and conclusion The other researchers did not find such percentage of pyramidal immunoreactive neurons in this amygdaloid nucleus. If we compare our results with the results of the ather researchers we can conclude that all pyramidal NPY immunoreactive neurons found in this human amygdaloid nucleus belong to the class I of neurons, and that all nonpyramidal NPY immunoreactive neurons belong to the class II of neurons described by other researchers. We suppose that all found pyramidal neurons were projectional.
Surgical treatment of the supraglottic laryngeal carcinoma
Authors: Petrovic Zeljko , Djordjevic Vladimir , Nesic Vladimir
Published: December 2008

This is a retrospective analysis of 439 patients with supraglottic laryngeal cancer primary surgically treated in the period 1976-1999. The objectives of our study were to analyze the localizations as well as local and regional tumor spread, frequency of occult and palpable cervical metastases, the incidence of local and regional recurrences, five-year survival rate and functional results of supraglottic partial horizontal laryngectomies. A retrospective analysis of operated patients was carried out. T1 tumor was prevalent in 184 (42%) patients, T2 in 228 (52%) patients, and T3 tumor in 27 (6%) of cases. Clinically negative finding of the neck was found in 369 (84%) patients, and metastasis N1 was established in 70 (16%) patients. The patients with clinically negative cervical finding underwent selective neck dissection, while N1 metastasis patients were subjected to a selective or modified radical neck dissection. Five-year disease-free survival rate was 76% (334/439).