bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystal structure of zebrafish complement 1qA globular domain
Authors: Yuan Hongyu , Chen Rong , Tariq Mansoor , Liu Yanjie , Sun Yaping , Xia Chun
Published: July 2016

C1q contains three globular domains (C1qgD) that are the key functional component of the classical complement system. C1qgD can interact with important immune molecules, including IgG and C‐reactive protein (CRP) to form defense systems to protect animals. Here, the first non‐mammalian structure, zebrafish C1qA globular domain (Dare‐C1qAgD) was solved. Although the overall architecture of Dare‐C1qAgD is similar to human C1qA, residues involved in C1qBgD, C1qCgD, and CRP binding are somewhat different while residues involved in IgG binding are not present in zebrafish. The structure gives insight into how human and fish C1qA evolved from an ancestral protein.
NMR characterization of dilauroyl phosphatidylcholine in adsorbed monolayers at fluid interfaces studied by multiscale computations
Authors: Tsoneva Yana , Tadjer Alia , Mineva Tzonka
Published: July 2016

Structural characteristics of model monolayers of dilauroyl phosphatidylcholine (1,2‐dilauroyl‐sn‐glycerol‐3‐phosphatidylcholine [DLPC]) adsorbed at the water/vapors and water/octane interfaces were studied by means of computational chemistry methods. Coarse‐grained, followed by all‐atom molecular dynamics simulations were used to obtain the monolayers equilibrium structures at room temperature at both fluid interfaces. The analysis of the polar head orientation, polar region thickness, tail lengths, and NMR order parameter revealed that the different interface composition affects only the tail lengths and their orientation with respect to the interface. At the octane/water boundary the DLPC tails are less extended than the tails at the water/vacuum interface and are rather significantly tilted or multiply folded. Very similar structuring of the polar DLPC region at both studied boundaries was established. Dynamic 13C NMR chemical shift values, δ(13C) computed with density functional theory allowed to identify the interface effect on the DLPC molecular structure and the intramolecular motions in the adsorbed monolayer at the room temperature equilibrium. Detailed analysis of these dynamic δ(13C) values compared with available experimental data and static δ(13C) estimates of one DLPC low‐energy conformer are presented and discussed.
Chemical inhomogeneity of SiOx dissociation by catalytic Au at a relatively low temperature
Authors: Sharma Manoj K. , Lee Kyoung‐Jae , Ihm Kyuwook
Published: July 2016

Sporadic catalytic decomposition because of the presence of Au grains is a significant issue to be clarified in electronic devices. Here, we report the inhomogeneous dissociation of native silicon oxide depending on the electronic structure of Au grains using scanning photoelectron microscopy. Upon annealing, the oxygen atoms dissociated from native SiOx layer out‐diffuses in non‐uniform manner, resulting in oxidize the Au layer. Valence band spectra showed that the spit‐orbit splitting, directly related to the coordination number, differs from site to site. Scanning photoelectron microscopy images show that dissociated SiOx coincides with the regions where low‐coordinated Au resides. These results imply that Au with low coordination number activated the dissociation of SiOx and open new pathway to remove undesirable oxide layer at relatively low temperature. Copyright © 2016 John Wiley & Sons, Ltd.
QTL mapping including codominant SNP markers with ploidy level information in a sugarcane progeny
Authors: Costa E. A. , Anoni C. O. , Mancini M. C. , Santos F. R. C. , Marconi T. G. , Gazaffi R. , Pastina M. M. , Perecin D. , Mollinari M. , Xavier M. A. , Pinto L. R. , Souza A. P. , Garcia A. A. F.
Published: July 2016

Quantitative trait locus (QTL) mapping contributes to sugarcane (Saccharum spp.) breeding programs by providing information about the genetic effects, positioning and number of QTLs. Combined with marker-assisted selection, it can help breeders reduce the time required to develop new sugarcane varieties. We performed a QTL mapping study for important agronomic traits in sugarcane using the composite interval mapping method for outcrossed species. A new approach allowing the 1:2:1 segregation ratio and different ploidy levels for SNP markers was used to construct an integrated genetic linkage map that also includes AFLP and SSR markers. Were used 688 molecular markers with 1:1, 3:1 and 1:2:1 segregation ratios. A total of 187 individuals from a bi-parental cross (IACSP95-3018 and IACSP93-3046) were assayed across multiple harvests from two locations. The evaluated yield components included stalk diameter (SD), stalk weight (SW), stalk height (SH), fiber percentage (Fiber), sucrose content (Pol) and soluble solid content (Brix). The genetic linkage map covered 4512.6 cM and had 118 linkage groups corresponding to 16 putative homology groups. A total of 25 QTL were detected for SD (six QTL), SW (five QTL), SH (four QTL), Fiber (five QTL), Pol (two QTL) and Brix (three QTL). The percentage of phenotypic variation explained by each QTL ranged from 0.069 to 3.87 %, with a low individual effect because of the high ploidy level. The mapping model provided estimates of the segregation ratio of each mapped QTL (1:2:1, 3:1 or 1:1). Our results provide information about the genetic organization of the sugarcane genome and constitute the first step toward a better dissection of complex traits.
Comparative study between staples and eight plate in the management of coronal plane deformities of the knee in skeletally immature children
Authors: Kumar Arvind , Gaba Sahil , Sud Alok , Mandlecha Pushpvardhan , Goel Lakshay , Nayak Mayur
Published: July 2016

Purpose

To compare two commonly used methods of temporary hemiepiphysiodesis (staples and figure of eight plate) in the management of coronal plane deformities of the knee in skeletally immature children.

Methods

This prospective study was conducted between November 2012 and November 2015. A total of 40 patients with 67 affected knee joints, having at least 1 year of skeletal growth remaining, were included in the study. Angular correction was measured by recording the mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and anatomical tibio-femoral angle (TFA) (for the overall alignment of lower limbs). Implant removal was done after 5° of overcorrection was achieved. The rate of correction (° per month) and complications related to each technique were recorded.

Results

The most common diagnosis was idiopathic genu valgum. The overall rate of correction (TFA) was 1.2° for staples and 1.4° for eight plate ( p = 0.70, not statistically significant). The correction in mLDFA was statistically better in the eight plate group, whereas an opposite trend was recorded in mMPTA. Implant-related complications were present in two cases of the staples group.

Conclusion

Although the overall correction rate was similar in both groups, implant-related complications were lower with figure of eight plate. In idiopathic genu valgum (the most common diagnosis), the correction was statistically better in the eight plate group. We recommend figure of eight plate over staples in managing these deformities.
Chemoradiotherapy with Brachytherapy or Electron Therapy Boost for Locally Advanced Squamous Cell Carcinoma of the Anus—Reducing the Colostomy Rate
Authors: Kent C. , Bessell E. M. , Scholefield J. H. , Chappell S. , Marsh L. , Mills J. , Sayers I.
Published: July 2016

Purpose

The aim of this study is to determine overall survival, disease-specific survival and stoma-free survival after treatment of squamous cell carcinoma of the anus with chemoradiotherapy followed by brachytherapy or electron boost in a recent cohort of patients.

Methods

Fifty-two patients (median age 62 years) were treated with radical chemoradiotherapy (mitomycin C, infusional 5-fluorouracil concurrently with conformal radical radiotherapy 45 Gy in 25 fractions over 5 weeks) followed by a radiotherapy boost between 1 December 2000 and 30 April 2011. Follow-up was to 30 November 2014. Thirty-six patients received a boost (15–20 Gy) over 2 days with 192Ir needle brachytherapy for anal canal tumours, and 16 patients received electron beam therapy (20 Gy in 10 fractions in 2 weeks) for anal margin tumours. A defunctioning stoma was only created prior to chemoradiotherapy for fistula or severe anal pain.

Results

The overall survival for the 36 patients treated with chemoradiotherapy followed by brachytherapy was 75 % (95 % CI, 61–89) at 5 years, the disease-specific survival was 91 % (95 % CI, 81–101 %), and the stoma-free survival was 97 % (95 % CI, 91–103 %) all at 5 years. For the 16 patients treated with an electron boost for anal margin tumours, the 5-year overall survival, disease-specific survival and stoma-free survival were 68 % (95 % CI, 44–92 %), 78 % (95 % CI, 56–100 %) and 80 % (95 % CI, 60–100 %), respectively.

Conclusions

A very low stoma formation rate can be obtained with radical chemoradiotherapy followed by a brachytherapy boost for squamous cell carcinoma of the anal canal but not with an electron boost for anal margin tumours.
MULTISYMPLECTIC VARIATIONAL INTEGRATORS FOR NONSMOOTH LAGRANGIAN CONTINUUM MECHANICS
Authors: DEMOURES FRANÇOIS , GAY-BALMAZ FRANÇOIS , RATIU TUDOR S.
Published: July 2016

This paper develops the theory of multisymplectic variational integrators for nonsmooth continuum mechanics with constraints. Typical problems are the impact of an elastic body on a rigid plate or the collision of two elastic bodies. The integrators are obtained by combining, at the continuous and discrete levels, the variational multisymplectic formulation of nonsmooth continuum mechanics with the generalized Lagrange multiplier approach for optimization problems with nonsmooth constraints. These integrators verify a spacetime multisymplectic formula that generalizes the symplectic property of time integrators. In addition, they preserve the energy during the impact. In the presence of symmetry, a discrete version of the Noether theorem is verified. All these properties are inherited from the variational character of the integrator. Numerical illustrations are presented.
An evaluation of community-based cognitive stimulation therapy: a pilot study with an Irish population of people with dementia
Authors: Kelly M. E. , Finan S. , Lawless M. , Scully N. , Fitzpatrick J. , Quigley M. , Tyrrell F. , O’Regan A. , Devane A.
Published: July 2016

Objectives

Research shows that cognitive stimulation therapy (CST) improves cognitive function, quality of life, and well-being of people with mild–moderate dementia. Despite consistent evidence and recommendations, CST is not routinely available in Ireland post-diagnosis. The aim of the current research was to develop and evaluate community-based CST for people with mild–moderate dementia, run by the Alzheimer Society of Ireland across four pilot sites in Ireland.

Methods

Participants with mild–moderate dementia attended once weekly CST sessions for 14 weeks. Baseline and post-intervention assessments were completed by CST participants, carers, and CST facilitators. Primary outcomes of interest for CST participants included quality of life (Quality of Life in Alzheimer Disease Scale), cognitive function (Montreal Cognitive Assessment), and subjective cognitive function (Memory Awareness Rating Scale-Functioning Subscale). Secondary outcomes included well-being, cognitive ability, satisfaction with cognitive performance, and engagement and confidence of CST participants; well-being of carers; and job satisfaction of facilitators. Post-intervention interviews supplemented quantitative analyses.

Results

In total, 20 CST participants, 17 carers, and six CST facilitators completed evaluation assessments. Results showed that CST improved participants’ satisfaction with cognitive performance (p=0.002), level of engagement (p=0.046), level of confidence (p=0.026). Improvements on subjective cognitive function just fell short of significance (p=0.055). Qualitative analysis of interview data identified consistent themes of cognitive and overall benefits of CST; and provided support for quantitative data.

Conclusions

Community-based CST positively impacted the lives of people with dementia and their families. This study supports prior recommendations that CST should be made routinely available to people with mild–moderate dementia, particularly in light of the lack of post-diagnostic interventions currently offered in Ireland.
Dynamics of red blood cells in oscillating shear flow
Authors: Cordasco Daniel , Bagchi Prosenjit
Published: July 2016

We present a three-dimensional computational study of fully deformable red blood cells of the biconcave resting shape subject to sinusoidally oscillating shear flow. A comprehensive analysis of the cell dynamics and deformation response is considered over a wide range of flow frequency, shear rate amplitude and viscosity ratio. We observe that the cell exhibits either a periodic motion or a chaotic motion. In the periodic motion, the cell reverses its orientation either by passing through the flow direction (horizontal axis) or by passing through the flow gradient (vertical axis). The chaotic dynamics is characterized by a non-periodic sequence of horizontal and vertical reversals. The study provides the first conclusive evidence of the chaotic dynamics of fully deformable cells in oscillating flow using a deterministic numerical model without the introduction of any stochastic noise. In certain regimes of the periodic motion, the initial conditions are completely forgotten and the cells become entrained in the same sequence of horizontal reversals. We show that chaos is only possible in certain frequency bands when the cell membrane can rotate by a certain amount, allowing the cells to swing near the maximum shear rate. As such, the bifurcation between the horizontal and vertical attractors in phase space always occurs via a swinging inflection. While the reversal sequence evolves in an unpredictable way in the chaotic regime, we find a novel result that there exists a critical inclination angle at the instant of flow reversal which determines whether a vertical or horizontal reversal takes place, and is independent of the flow frequency. The chaotic dynamics, however, occurs at a viscosity ratio less than the physiological values. We further show that the cell shape in oscillatory shear at large amplitude exhibits a remarkable departure from the biconcave shape, and that the deformation is significantly greater than that in steady shear flow. A large compression of the cells occurs during the reversals which leads to over/undershoots in the deformation parameter. We show that due to the large deformation experienced by the cells, the regions of chaos in parameter space diminish and eventually disappear at high shear rate, in contradiction to the prediction of reduced-order models. While the findings bolster support for reduced-order models at low shear rate, they also underscore the important role that the cell deformation plays in large-amplitude oscillatory flows.
Distance methods applied to a semi-deterministic clustering process
Authors: Diggle Peter
Published: July 2016

Aggregated spatial patterns may be generated by a clustering process (see, for example, Bartlett (1964)) in which ‘parent’ events are distributed completely at random, and produce, independently, random numbers of ‘offspring’ according to some distribution Pn; the position of each offspring relative to its parent is governed, independently, by a given bivariate distribution. Parents and offspring are assumed indistinguishable. For such a process, Bartlett (1974) shows that the distribution function F of the distance, X say, from a randomly selected point to the nearest event is given by

where ρ denotes the mean number of parents per unit area, A is the circle with centre the origin and radius x, and E(ds) denotes the event ‘no offspring in A from parent in ds’.
Spatial dynamics of biological populations
Authors: Renshaw Eric
Published: July 2016

Considerable interest has recently been shown in the spatial spread of infection between static individuals. A different approach yielding similar types of processes is to allow the individuals themselves to migrate from site to site. This movement may be physical migration, mutation from one type of organism to another, or it may even represent an approximation to the initial development of a spatial epidemic. We shall consider the population to be distributed amongst either a finite number of sites (model A), or an infinite number situated at the nodes of a lattice (model B). In this latter situation individuals are only allowed to migrate between sites which are nearest neighbours, and the transition rates are assumed to be spatially homogeneous. Individuals at each site undertake a simple birth-death-migration-immigration process.
The estimation of the parameters in epidemics
Authors: Gough Kevin
Published: July 2016

The General Stochastic Epidemic model is extended to allow for outside infection. The likelihood is derived for small households, and the difficulties for larger populations are discussed.
Plankton patchiness
Authors: Steele John
Published: July 2016

Variability in space of plankton can arise from stochastic effects on growth and predation, and should be smoothed by horizontal diffusion of the water. The interactions of these factors within a non-linear system should permit small-scale perturbations to appear as larger-scale patches. A simple simulation illustrates this possibility.
Competition processes on a lattice
Authors: Clifford Peter
Published: July 2016

Some years ago Hammersley and Clifford considered the problem of assigning probabilities to colourings of a graph according to certain local conditions. Subsequent expositions such as those of Grimmett, Besag and Preston, whilst providing more elegant derivations, have shown that the assignment of probabilities coincides with the limiting distribution of spatial-temporal processes arising from theoretical physics. There has been relatively little work on spatial-temporal processes outside this class. In this paper the approximate behaviour of an alternative class of processes is investigated. Topics will include statistical estimation of parameters and existence of unique equilibria.
MALDI-TOF MS in clinical parasitology: applications, constraints and prospects
Authors: SINGHAL NEELJA , KUMAR MANISH , VIRDI JUGSHARAN SINGH
Published: July 2016

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is currently being used for rapid and reproducible identification of bacteria, viruses and fungi in clinical microbiological laboratories. However, some studies have also reported the use of MALDI-TOF MS for identification of parasites, likeLeishmania, Giardia, Cryptosporidium, Entamoeba, ticks and fleas. The present review collates all the information available on the use of this technique for parasites, in an effort to assess its applicability and the constraints for identification/diagnosis of parasites and diseases caused by them. Though MALDI-TOF MS-based identification of parasites is currently done by reference laboratories only, in future, this promising technology might surely replace/augment molecular methods in clinical parasitology laboratories.
Liberalism at High Latitudes: The Politics of Polar Exploration in the Habsburg Monarchy
Authors: Walsh Stephen A.
Published: July 2016

In the autumn of 1874, Austrian popular society seemed ablaze with talk of ice. The Habsburg monarchy's first major polar expedition was returning, and, as the German geographer August Petermann put it, “No field commander, returning home with his army victorious from battle, could be received more magnificently and enthusiastically than this small band of twenty- two men.” The first published narrative of the expedition was released in Vienna around 24 September and had sold out of its print run of forty-five thousand copies by 27 September. This figure, however, is dwarfed by contemporary estimates of the multitude that turned up to welcome the explorers to Vienna on 25 September: around a quarter million, or approximately one-fourth of the city's entire population. Although such figures should be taken with a grain of salt, the festivities that greeted the explorers involved possibly the largest crowds seen on the streets of Vienna between the revolutions of 1848–49 and the mass marches of the Social Democratic Party in support of universal male suffrage around the turn of the century.
The Internet's (New) Usage Problems
Authors: Vriesendorp Hielke
Published: July 2016

In the previous issue of English Today, Lukač (2016) discusses the increasingly important role of online language authorities for users of the internet who are looking for usage advice. However, prescriptivism also reaches these users when they are not actively looking for it. They encounter advice in newsfeeds in different social media, such as Twitter and Facebook, and some of them join online groups to discuss usage problems. The standard language ideology seems to have established itself firmly on these new platforms, adapting itself in the process. Articles on usage shared on social media are almost without exception in the form of lists with eye-catching ‘clickbaity’ titles (e.g. ‘7 Grammar Mistakes That Make You Look Dumb’), and their most important topics differ strongly from those of traditional prescriptivism.
Almost quasi-isometries and more non-C*-exact groups
Authors: FINN-SELL MARTIN
Published: July 2016

We study permanence results for almost quasi-isometries, the maps arising from the Gromov construction of finitely generated random groups that contain expanders (and hence that are notC*-exact). We show that the image of a sequence of finite graphs of large girth and controlled vertex degrees under an almost quasi-isometry does not have Guoliang Yu's property A. We use this result to broaden the application of Gromov's techniques to sequences of graphs which are not necessarily expanders. Thus, we obtain more examples of finitely generated non-C*-exact groups.
The distribution of k-free numbers and the derivative of the Riemann zeta-function
Authors: MENG XIANCHANG
Published: July 2016

Under the Riemann Hypothesis, we connect the distribution of k-free numbers with the derivative of the Riemann zeta-function at nontrivial zeros of ζ(s). Moreover, with additional assumptions, we prove the existence of a limiting distribution of $e^{-\frac{y}{2k}}M_k(e^y)$ and study the tail of the limiting distribution, where $M_k(x)=\sum_{n\leq x}\mu_k(n)-{x}/{\zeta(k)}$ and μk(n) is the characteristic function of k-free numbers. Finally, we make a conjecture about the maximum order of Mk(x) by heuristic analysis on the tail of the limiting distribution.
Relationality and Its Chinese Characteristics
Authors: Kavalski Emilian
Published: July 2016

China's expanding outreach and diversifying roles have provided a novel context for the ongoing reconsiderations of world politics. As a result, inquiries into how China thinks and in what way its history and traditions inform the idiosyncrasies of China's international outlook have grown into a cottage industry both in International Relations (IR) and across the full spectrum of the humanities and social sciences. In this setting, Beijing's external relations draw attention both because of their agency and due to the specificities of China's individual engagements. What has remained overlooked, however, is that such preoccupation with China has been paralleled by the emergence of a relational turn in IR. One could argue that this is not a mere coincidence. Relationality in IR has become prominent not least because of its simultaneous appropriation by both the so-called Western and non-Western (especially, Chinese) perspectives on world affairs. In this respect, the three books under review seem to have a shared interest in interpreting China's growing significance on the world stage through such relational lenses. Together the three books under review illustrate vividly that the complex patterns of global life resonate with relationality and dynamism, rather than the static and spatial arrangements implicit in the fetishized currency of self-other/centre-periphery/hegemon-challenger models underpinning the binary metanarratives of IR.
Terrain Matching Positioning Method Based on Node Multi-information Fusion
Authors: Li Ye , Wang Rupeng , Chen Pengyun , Shen Peng , Jiang Yanqing
Published: July 2016

Measurement bias and lack of terrain features often cause false peaks during underwater terrain matching positioning, that is, there is more than one peak near the real position. Previous methods to address this problem have increased the number of measurement beams, but this also increases the data processing time and energy consumption. At the same time, the ratio of measured information that is used does not increase. In other words, we should increase the ratio of measured information that is used, not simply increase the amount of information that is measured. Conventional matching algorithms only use the height of nodes without considering surface information, which is composed of height and the position of multiple nodes in three-dimensional space. Multi-beam sonar can obtain the three-dimensional distribution of terrain nodes. This node information is not just a height sequence, as it is used in previous methods. If we consider the nodes as a three-dimensional distribution of points with height and position information, this increases the matching position information and more of the terrain features can be extracted from the same measured data. Hence, in this paper, a terrain positioning method called the Node Multi-information Fusion (NMIF) is presented. This method focuses on improving the stability and accuracy degraded by bias in the Digital Elevation Map (DEM), terrain repeatability, and other factors. First, the concept of a Single Node Data Packet (SNDP) is introduced. The SNDP includes elevation and surface information surrounding the node, such as roughness, gradient, and slope. This additional topographic feature information improves the robustness and accuracy of the system. A computer simulation using actual ocean bottom topography verifies the advantages of the proposed NMIF algorithm.
Towards a Cognitive Model of Human Mobility: An Investigation of Tactile Perception for use in Mobility Devices
Authors: Pissaloux E. , Velazquez R. , Hersh M. , Uzan G.
Published: July 2016

This paper reports the results of the first three in a series of experiments on tactile perception which form part of a larger project on tactile perceptions and spatial representations and the design of tactile interfaces for mobility devices for blind, partially sighted and deafblind people. The results indicate the potential of tactile interfaces, including to support environmental exploration and mobility. The participants showed reasonably good ability to determine the direction of motion of an arrow, with best recognition rates in the up and right directions. They showed reasonably good ability to use a tactile interface to detect and avoid obstacles after a very short learning period and more limited ability to learn and remember an environmental representation using information from a tactile interface and walking through the environment without specific instructions.
L'Étude Mathématique des Assurances non Viagères dans l'Europe Continentale Occidentale
Authors: Ammeter H. , Depoid P. , de Finetti B.
Published: July 2016

Ce rapport n'a pas le but de résumer toute la littérature actuarielle sur les assurances non viagères: on se proposait de tracer le fil conducteur de quelques uns des développements d'idées où l'apport des mathématiques est plus profond et, en particulier, de ceux où il semble qu'il y aura encore à travailler longtemps. A ce compte, seulement quelques étapes pouvaient être explicitement mentionnées dans le texte, tandis qu'une bibliographic complète aurait dû suivre à la fin du rapport.

Maintes circonstances ont restreint le temps à disposition des rapporteurs et ont augmenté les difficultés d'un travail en commun à distance; sans doute quelques contributions ont échappé ou n'ont pas reçu le relief qu'il aurait fallu leur donner. Les auteurs prient de bien vouloir justifier les omissions par ces circonstances, et de les leur signaler.

L'assurance sur la vie et les assurances non viagères semblent présenter des différences essentielles, soit au point de vue de leur objet (indemnité d'une perte dans le deuxième cas, mais non dans le premier), soit au point de vue de leur méthode (théorie mathématique complétement développée dès longtemps pour le premier cas, mais non dans le deuxième).

Ya-t-il néanmoins une notion unique d'assurance, en général, qui comprenne toutes les deux? Est-il possible de concevoir d'une façon unique l'application du calcul des probabilités et des méthodes mathématiques qui le traduisent, dans le champ de l'assurance en général? Ou ya-t-il des limitations, ou des circonstances qui obligent à distinguer à cet effet les deux champs de l'assurance sur la vie et de l'assurance non viagère?
The Influence of Climate on Fire Damage
Authors: Andersson Hans
Published: July 2016

In his paper “Actuarial Activity in General Insurance in the Northern Countries of Europe” L. Wilhelmsen gives amongst other things an account of the work carried on by Centralstället för nordisk ömsesidig Brandförsäkringsstatistik (CNÖB, the Northern Central Office for Fire Insurance Statistics from Mutual Companies). In this he states that one part of the organisation's work is the carrying out of special investigations of current problems with material collected on each occasion for the purpose.

The object of this paper is to report investigations carried out in CNÖB on the connection between temperature and risk premium in fire insurance. The material used is made up exclusively of civil risks (buildings) and the material has been taken from Sweden and Norway. The background to the investigation consists in the fact that in Scandinavia the risk premiums for fire insurance show an apparent geographical variation, in that the amount clearly increases in the most northerly provinces.

As we know that the fire damage directly or indirectly caused by heating systems (chimney fires, cracked building blocks, embers from fireplaces or chimneys etc.) represents a large proportion of the damage in civil risks (40-50%, in some materials 60% or more), that the proportion is greatest in the northern parts and that in the Swedish material about 50% of the damage in any one area falls in the four months December to March, it is quite reasonable to trace the influence of the temperature factor behind the geographical variation; the colder the climate, the more lighting of fires and the more damage. This line of argument is connected exclusively to the frequency of damage; we shall return later to the mean degree of damage.
Individual Risk Theory and Risk Statistics as Applied to Fire Insurance
Authors: Almer Bertil
Published: July 2016

Risk Theory for Life Insurance is simplified by the fact that the distribution Ψ (x) of claim amounts x approximately coincides with the distribution of “Risk sums” (not exactly, owing to differaences in the claim frequency with age and actual state of health), ond this distribution is comparatively stable.—The dependence on the claim frequency is eliminated by the introduction of a new time variable, and the system reduced to a (stationary) Poisson Process, which should be valid at least for large risk systems and for the total Life branch for a moderate sequence of years.

In almost all non-life branches, partial claims will dominate and Ψ (x) can only be determined by risk statistics, leaving a certain space of indetermination, in particular for large claims and for mediumsized statistical risk groups.

In my previous analyses, in particular New York 1957, interest has been concentrated on traffic and motor car insurance, where the risk depends on cars insured and on the meeting traffic (including road conditions). In one year the same car can be involved in many accidents and double claims (=collisions) are rather frequent.—According to my experience, this system is best represented by a sequence of single and double risk situations in time (for individual cars or for risk groups).

Analysis is simplified for Fire Insurance (and many other non-life branches), because the risk system is composed of mostly independent insurances (or risk objects), which are best described by the ordinary Individual Risk Theory.
A Remark on the Principle of Zero Utility
Authors: Gerber Hans U.
Published: July 2016

Let u(x) be a utility function, i.e., a function with u′(x)>0, u″(x)<0 for all x. If S is a risk to be insured (a random variable), the premium P = P(x) is obtained as the solution of the equation

which is the condition that the premium is fair in terms of utility. It is clear that an affine transformation of u generates the same principle of premium calculation. To avoid this ambiguity, one can standardize the utility function in the sense that

for an arbitrarily chosen point y. Alternatively, one can consider the risk aversion

which is the same for all affine transformations of a utility function.

Given the risk aversion r(x), the standardized utility function can be retrieved from the formula

It is easily verified that this expression satisfies (2) and (3).

The following lemma states that the greater the risk aversion the greater the premium, a result that does not surprise.
Actuarial Remarks on Planning and Controlling in Reinsurance
Authors: Straub Erwin
Published: July 2016

Planning is, or ought to be, an ever-developing process in which virtually each member of the company has to be involved. Planning without controlling, i.e., without feedback, planning on its own, is useless.

In the first part of the present note, general aspects of planning are briefly described inasfar as they are relevant to possible treatment by actuarial methods.

The circles in the above figure represent what could be called the hardware of planning consisting of three sets of figures, namely

• Actual figures describing the most recent reality. Most of these figures are part of what is usually called the Earnings Statement (EST).

• Forecasts for the near future, say the next three years. Most of these figures are contained in the Planning Budget (PLB).

• Control figures or signals in the sense of a “bread-line” expressing, for example, how much the company should earn as a minimum in order to remain self-financing. Such figures are calculated on the basis of so-called Return on Equity considerations and they are found in a corresponding ROE-document.

By software we mean everything done with the hardware described above, i.e., primarily the comparison of figures from different domains of the hardware on different levels within the organisation of the company, the analysis, for example, of deviations between actual and planned, the conclusions to be taken from such analyses and the planning of new actions as a consequence.

In the above graph, circles symbolize the hardware and arrows indicate the software.

Also non-numeric planning instruments (e.g., project planning, action plans, assessment and decisions) are considered to be part of the planning software.
Une classe des processus de risque et leur algorithme de resolution
Authors: Franckx Ed.
Published: July 2016

A l'encontre de la théorie classique de l'assurance collective, qui s'intéresse plus particulièrement aux problèmes asymptotiques, les praticiens de l'assurance „non life” et les autorités de contrôle souhaitent disposer d'une méthode effective de calcul permettant de chiffrer la valeur réelle des probabilités de ruine dans un avenir plus ou moins rapproché.

Telle fut la remarque de notre collègue Bichsel au colloque d'ASTIN en 1967 à Arnhem. Dans le bulletin des Actuaires Suisses nous avons publié deux notes sur „une théorie opérationnelle du risque”. A la base se trouve l'emploi des processus markoviens discrets. Ces études prolongeaient un premier essai, exposé à l'Université de Trieste en 1963; une conférence donnée à Tel Aviv en 1967 développait le même thème. Dans un autre domaine, celui de la Recherche Opérationnelle, les ingénieurs utilisent depuis longtemps les mêmes processus de Markov pour étudier, par la dynamique stochastique, l'évolution d'un système aléatoire.
On Additive Premium Calculation Principles
Authors: Gerber Hans U.
Published: July 2016

A premium calculation principle is a general rule that assigns a premium P to any given risk S. Intuitively, P is what the insurance carrier charges (apart from an expense allowance) for taking over the risk S (see [3], p. 85-87). Mathematically, S is a random variable, and P depends on S through its distribution function. The value of P may be finite or infinite; in the latter case we speak of an uninsurable risk.

A premium calculation principle is called additive, if the premium assigned to the sum of two independent risks is the sum of the premiums that are assigned to the two risks individually. For example, the variance principle, P = E[S] + β Var [S] (β > o), is additive, because the variance of the sum of independent random variables equals the sum of the variances. Additivity is a very desirable property, from a theoretical as well as from a practical point of view (as pointed out by Borch [2], p. 429).

The variance principle is not entirely satisfactory for various reasons. For one thing it does not take account of the skewness of S (a risk whose distribution is skewed to the right seems to be more dangerous than one with a symmetrical distribution). Furthermore, it produces in some cases a premium P that exceeds S with probability one (example: β = .3, S = o or 10, each with probability 1/2).
Risk Bearing and the Insurance Market
Authors: Bühlmann Hans , Gerber Hans U.
Published: July 2016

Stimulated by Karl Borch's paper [3] we have tried to analyze the paper written by K. Arrow [1] in 1953. Contrary to Borch's opinion we have some doubt whether this work contains a theory of insurance as a special case. Nevertheless, it has inspired us to this note, which tries to develop a somewhat more realistic model. As a matter of fact, our development is more in the spirit of another paper by Arrow [2]. We, however, have chosen a more general setup, and we believe that our treatment is also different.
Some Transient Results on the M/SM/1 Special Semi-Markov Model in Risk and Queueing Theories
Authors: Janssen Jacques
Published: July 2016

We consider a usual situation in risk theory for which the arrival process is a Poisson process and the claim process a positive (J — X) process inducing a semi-Markov process. The equivalent in queueing theory is the M/SM/1 model introduced for the first time by Neuts (1966).

For both models, we give an explicit expression of the probability of non-ruin on [o, t] starting with u as initial reserve and of the waiting time distribution of the last customer arrived before t. “Explicit expression” means in terms of the matrix of the aggregate claims distributions.
The Solvency Margin in Non-Life Insurance Companies
Authors: de Wit G. W. , Kastelijn W. M.
Published: July 2016

Much attention has been paid in the last ten years to the necessary solvency margin especially as influenced by risk theory considerations. In these calculations, by which the solvency margin is determined in such a way that the probability of ruin remains under a specified norm, such factors as type of insurance, size of portfolio, reinsurance etc. play an essential role.

In these calculations, based on pure risk theory, there is thus no attention paid to risks in the investment field, in the area of costs, etc. Yet one must not forget that the solvency margin must also act as a buffer against these uncertainties, in other words the solvency margin must be large enough to cover all risks to which the concern is liable, within stipulated limits of certainty.

One drawback of a pure risk theoretical approach, as interpreted above, is that the bases of the risk theory are often difficult to translate into practical terms, and furthermore will differ from company to company. The latter is also the case with the size of portfolio, reinsurance, etc. However, if this could all be translated into practical terms in the right way, the results would upset relations between competitors, so that it seems natural to make the required solvency margin the same for all companies.

Seen in this light Campagne's approach is of great importance—already in 1948 he realized that a scientific basis for the size of the solvency margin was necessary. He confined himself to the life insurance industry, and based his calculations on the idea that the total results of the companies working in a country should be such that, ceteris paribus, the chance of bankruptcy remains below a stipulated norm.
An Extension of an Invariance Property of the Swiss Premium Calculation Principle
Authors: Goovaerts M. J. , de Vylder F. , Mertens F. , Hardy R.
Published: July 2016

Some of the results obtained in an earlier paper entitled “An Invariance property of the Swiss premium calculation principle” by F. De Vylder and M. Goovaerts (1979) are generalized. For that purpose the notion of additivity and iterativity is extended. Some rather general characterization theorems for some premium calculation principles are obtained.
A Characterization of the Esscher-Transformation
Authors: Kremer Erhard
Published: July 2016

One of the central problems in risk theory is the calculation of the distribution function F of aggregate claims of a portfolio. Whereas formerly mainly approximation methods could be used, nowadays the increased speed of the computers allows application of iterative methods of numerical mathematics (see Bertram (1981), Küpper (1971) and Strauss (1976)). Nevertheless some of the classical approximation methods are still of some interest, especially a method developed by Esscher (1932).

The idea of this so called Esscher-approximation (see Esscher (1932), Grandell and Widaeus (1969) and Gerber (1980)) is rather simple:

In order to calculate 1 –F(x) for large x one transforms F into a distribution function such that the mean value of is equal to x and applies the Edgeworth expansion to the density of The reason for applying the transformation is the fact that the Edgeworth expansion produces good results for x near the mean value, but poor results in the tail (compare also Daniels (1954)).
The Lognormal Model for the Distribution of one Claim
Authors: Benckert Lars-Gunnar
Published: July 2016

The most important property of a distribution function to be used as a model for the distribution of one claim is of course that it fits the data well enough. If there is no natural truncation point in the data a more formal demand is that all the moments of the distribution function exist. Further, to be of a real value to the statistician, the chosen d.f. ought to be reasonably handy to use. As all the moments of the lognormal d.f. exist the first point to be checked is whether the lognormal d.f. fits the data. The other points on the list below are the qualities that I think are of the greatest value when using a distribution function, i.e. they reflect the handiness of the d.f.

Does the lognormal d.f.

1. Fit the data?

2. Give an unbiased and efficient estimate of the mean? It is important that this estimate is not too difficult to compute.

3. Give a practicable confidence interval of the mean?

4. Give a known distribution function of the estimate of the risk premium?

This paper is an attempt to give an affirmative answer to these questions. As the lognormal distribution function has been treated in the monograph “The lognormal distribution” by J. Aitchison and J. A. C. Brown (Cambridge University Press) the theory of this distribution function will not be dealt with more than necessary for the context.
Some Notes on the Statistical Theory of Extreme Values
Authors: Beard R. E.
Published: July 2016

In preparing the notes on the subjects for discussion at the 4th ASTIN Colloquium at Trieste [1] I used some of the material which formed the basis of a talk given to the Scandinavian Actuarial Societies in September 1962. The papers presented in Trieste have established on a firm mathematical footing the formula for the excess loss premium derived in my note but the discussions also showed that some of the other 1962 material would be of interest.

It will be appreciated that the question originally proposed, i.e. to calculate an excess of loss reinsurance premium when the only information available is the largest claim experienced in each of a succession of periods, was deliberately phrased in this form as being the most troublesome case likely to arise in practice. Clearly if other information is available it would not be rejected in arriving at a premium, but this immediately extends the problem to one of finding the best methods of combining information of different kinds. For example if, say, the largest 5 claims in each period are known, what technique will make the maximum use of the data? Such extensions of the problem are not discussed in this note. Furthermore, I am not unmindful of the valuable comment by Jung, “that there is a natural law which states that you can never get more out of a mincing machine than what you have put into it” [2].
A Theoretical Study of the No-Claim Bonus Problem
Authors: Derron Marcel
Published: July 2016

The no-claim bonus problem has given rise to a considerable amount of discussion throughout the whole world. There is quite a difference of opinion among the actuaries and other experts concerned in this field and several exchanges of view have taken place the last few years. The ASTIN section of the Permanent Committee has been well aware of this fact and it has devoted one Colloquium to this subject and discussed it at others.

In 1959 the major part of the La Baule meeting was dedicated to this subject and attention was focussed on this problem once again at Rattvik in 1961. Nevertheless controversies on this subject still continue. Almost every conference where the bonus problem is discussed is marked by a widespread difference of opinion.

As is well known, the claim frequencies under insurance policies show a considerable heterogeneity, especially in the early years. It is not possible to get homogeneous sub-groups by means of a continuous subdivision; what may be gained in homogeneity, is lost in credibility. It seems therefore that a subsequent adjustment of premiums according to the past claim record may well be a suitable way of obtaining a fair premium.

Those who are in favour of a rating procedure granting a bonus at a careful driver will stress that criticism is useless as long as no better solution is available, whereas actuaries who reject such a rating system argue that the unfairness of a flat rate is not at all eliminated by means of a bonus.