bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scanning electron microscope examination of the dental enameloid of the Cretaceous durophagous sharkPtychodussupports neoselachian classification
Authors: Hoffman Brian L. , Hageman Scott A. , Claycomb Gregory D. 
Published: August 2016

AbstractAlthoughPtychodusteeth are well known in Late Cretaceous marine deposits in North America and Europe and a few specimens with jaw elements have been discovered, the taxonomic position of the shark genusPtychodusis enigmatic due to the lack of preservation of diagnostic material other than teeth. These sharks possessed a pavement dentition suited to a diet of hard-shelled macroinvertebrates (durophagy), leading several studies to variously describePtychodusas a batoid, a hybodont shark, or a selachimorph. Members of the Selachimorpha share one dental synapomorphy, a triple-layered enameloid (TLE) consisting of an outer shiny-layered enameloid (SLE) of randomly oriented hydroxyapatite crystallites, a middle layer of parallel-bundled enameloid (PBE), and an inner layer of tangled-bundled enameloid (TBE). Batoids and hybodonts both have teeth with single crystallite enameloid (SCE). We examined teeth fromPtychoduscollected from the Lincoln Limestone of the Greenhorn Formation of Barton County, Kansas, and compared their enameloid ultrastructure with that of a Carboniferous hybodontiform and the Cretaceous lamniform sharkSqualicorax curvatusWilliston, 1900. Scanning electron microscopic examination ofPtychodusshows that crystallite bundling in the form of a TLE is evident in these teeth. The PBE is most apparent at transverse enameloid ridges ofPtychodusteeth. Columns of dentine penetrate into the tooth enameloid, and the crystallites near the dentine are randomly oriented. These observations bolster the argument thatPtychodusis a genus of highly specialized selachimorph shark, rather than a hybodont or batoid.
The effect of healthy dietary consumption on executive cognitive functioning in children and adolescents: a systematic review
Authors: Cohen J. F. W. , Gorski M. T. , Gruber S. A. , Kurdziel L. B. F. , Rimm E. B. 
Published: August 2016

AbstractA systematic review was conducted to evaluate whether healthier dietary consumption among children and adolescents impacts executive functioning. PubMed, Education Resources Information Center, PsychINFO and Thomson Reuters’ Web of Science databases were searched, and studies of executive functioning among children or adolescents aged 6–18 years, which examined food quality, macronutrients and/or foods, were included. Study quality was also assessed. In all, twenty-one studies met inclusion criteria. Among the twelve studies examining food quality (n 9) or macronutrient intakes (n 4), studies examining longer-term diet (n 6) showed positive associations between healthier overall diet quality and executive functioning, whereas the studies examining the acute impact of diet (n 6) were inconsistent but suggestive of improvements in executive functioning with better food quality. Among the ten studies examining foods, overall, there was a positive association between healthier foods (e.g. whole grains, fish, fruits and/or vegetables) and executive function, whereas less-healthy snack foods, sugar-sweetened beverages and red/processed meats were inversely associated with executive functioning. Taken together, evidence suggests a positive association between healthy dietary consumption and executive functioning. Additional studies examining the effects of healthier food consumption, as well as macronutrients, on executive functioning are warranted. These studies should ideally be conducted in controlled environments and use validated cognitive tests.
Dietary choline and betaine intake, choline-metabolising genetic polymorphisms and breast cancer risk: a case–control study in China
Authors: Du Yu-Feng , Luo Wei-Ping , Lin Fang-Yu , Lian Zhen-Qiang , Mo Xiong-Fei , Yan Bo , Xu Ming , Huang Wu-Qing , Huang Jing , Zhang Cai-Xia 
Published: August 2016

AbstractCholine and betaine are essential nutrients involved in one-carbon metabolism and have been hypothesised to affect breast cancer risk. Functional polymorphisms in genes encoding choline-related one-carbon metabolism enzymes, including phosphatidylethanolamineN-methyltransferase (PEMT), choline dehydrogenase (CHDH) and betaine-homocysteine methyltransferase (BHMT), have important roles in choline metabolism and may thus interact with dietary choline and betaine intake to modify breast cancer risk. This study aimed to investigate the interactive effect of polymorphisms inPEMT,BHMTandCHDHgenes with choline/betaine intake on breast cancer risk among Chinese women. This hospital-based case–control study consecutively recruited 570 cases with histologically confirmed breast cancer and 576 age-matched (5-year interval) controls. Choline and betaine intakes were assessed by a validated FFQ, and genotyping was conducted forPEMTrs7946,CHDHrs9001 andBHMTrs3733890. OR and 95 % CI were estimated using unconditional logistic regression. Compared with the highest quartile of choline intake, the lowest intake quartile showed a significant increased risk of breast cancer. The SNPPEMTrs7946,CHDHrs9001 andBHMTrs3733890 had no overall association with breast cancer, but a significant risk reduction was observed among postmenopausal women with AA genotype ofBHMTrs3733890 (OR 0·49; 95 % CI 0·25, 0·98). Significant interactions were observed between choline intake and SNPPEMTrs7946 (Pinteraction=0·029) andBHMTrs3733890 (Pinteraction=0·006) in relation to breast cancer risk. Our results suggest that SNPPEMTrs7946 andBHMTrs3733890 may interact with choline intake on breast cancer risk.
ISLANDERS, PROTESTANT MISSIONARIES, AND TRADITIONS REGARDING THE PAST IN NINETEENTH-CENTURY POLYNESIA
Authors: SMITH TOM 
Published: August 2016

ABSTRACTIn this article, I consider Polynesian genealogies, which took the form of epic poems composed and recited by specialist genealogists, and were handed down orally through generations of Polynesians. Some were written down in the nineteenth century, reaching an English-speaking audience through a number of works largely neglected by historians. In recent years, some anthropologists have downplayed the possibility of learning anything significant about Polynesian thought through English-language sources, but I show that there is still fresh historical insight to be gained in demonstrating how genealogies came to interact with the traditions of outsiders in the nineteenth century. While not seeking to make any absolute claims about genealogy itself, I analyse a wide body of English-language literature, relating chiefly to Hawai‘i, and see emerging from it suggestions of a dynamic Polynesian oral tradition responsive to political, social, and religious upheaval. Tellingly, Protestant missionaries arriving in the islands set their own view of history against this supposedly irrelevant tradition, and in doing so disagreed with late nineteenth-century European and American colonists and scholars who sought to emphasize the historical significance of genealogy. Thus, Western ideas about history found themselves confounded and fragmented by Polynesian traditions.
Graduation of the Annuitants' Experience.
Authors: King Albert E. 
Published: August 2016

The following notes were put together in order to collect into a convenient form for reference a few ideas as to what may have been the procedure adopted in the Graduation of the Annuitants' Experience.The Student is greatly indebted to Mr. Hardy for the information given both in the volume, “Account of the Principles and Methods, &amp;c,” and for affording subsequently, in his Lectures on Graduation, the opportunity to follow his work, and is again fortunate in having, for purposes of reference, the stores of information to be found in Mr. Ackland's paper to the Faculty, and Mr. Todhunter's Reviews in Vols. 38 and 43 of the Journal.
Valuation of a Pension Fund and Problems arising therefrom
Authors: Taylor F. G. 
Published: August 2016

The following remarks do not purport to contain any original matter but are merely an attempt to outline the routine followed in the valuation of a pension fund and to indicate certain problems which must be dealt with by the Actuary undertaking the valuation.The method of valuation is in the nature of an exercise in the use of the salary scale to give actual increases and not rates of increase.For the purposes of illustration a fund providing the following benefits is taken as an example.
The Method of Separation of Symbols in Finite Differences
Authors: Alison S. H. 
Published: August 2016

It is proposed to deal in somewhat greater detail than is customary with the reasons why we are entitled to separate symbols of operation from the quantities upon which they operate, combine them together as if they were ordinary symbols of quantity and interpret the results in terms of other operations.As a preliminary it may be well to say a word or two on the three primary laws of algebra, the law of distribution, of commutation and the index law and what these imply. Chrystal, in the first chapter of hisAlgebra, starts from the primitive notion of numbers (i.e.positive integers) and shows that the essential laws according to which these whole numbers combine are these three primary laws. He then shows how the meanings and properties of negative and fractional numbers are fixed by the condition that the meanings which are given to them are to be such as will give consistent results when we combine such numbers with other numbers according to the three primary laws. An illustration from the index law will perhaps make the point clearer.
The Solution of questions in Probability.
Authors: Henry A. , Freeman H. 
Published: August 2016

Probability questions are particularly difficult to the student, since the methods of solution are varied, and, unless the would-be solver has considerable experience, the best method of attack is not easily detected. The only way in which a satisfactory grasp of the subject can be attained is by working on a variety of problems of different kinds. The student will then find that questions in probability tend to fall into certain groups, but, even when he has arrived at this conclusion, he will discover, also, that the boundaries of these groups are by no means well defined, that a solution may often be reached by quite different lines of reasoning and that, except in the simplest cases, it will need all his experience to make a proper classification of any particular example.The object of this note is to assist students to work on these lines by affording him examples of various kinds—with hints for their solution. We have deliberately refrained from giving the solutionsin extenso, in order to encourage the student to work the examples through and sd obtain the practical experience which is so essential to proper knowledge.
Investment Bookkeeping.
Authors: Atkins F. C. 
Published: August 2016

The following is a short account of the various records used and of the entries necessitated by the purchase of, and subsequent dealing with, Stock Exchange investments. In other words, it endeavours to trace so much of their history as is written in the books of that department of an insurance company which deals with Stock Exchange securities, which may be called for convenience the Investment Department.Such a department would not keep the final books of account which provide the items for the Balance Sheet and other returns, all such information being obtained from the accountants' section. It would, however, decide upon the method of treatment of the many problems which arise in connection with security transactions.
Single Premium Policies.
Authors: Wood C. F. 
Published: August 2016

For some time past there has been a large amount of business transacted by Life Insurance Companies under what is commonly known as the “Super Tax Saving Scheme.”
A person who is liable for super tax effects with an insurance company a whole life or endowment assurance with or without profits by a single premium. The company then advances a large proportion of the single premium to the assured on the security of a first charge on the policy and bonuses, if any.
The Machinery of an Annuity Valuation
Authors: Willoughby-Meade G. 
Published: August 2016

It is hardly necessary to remind Members of this Society that little has been written in the Journal of the Institute on this subject.Annuities are essentially uniform, monotonous things, devoid for the most part of those ingenious gadgets and fascinating sideshows with which we are wont to dress up Life Insurance for the edification of the non-technical public. The annuity, however, for all its smooth exterior, is a thing to be handled with caution. We have always to keep in mind the following obvious but very important facts:—(a) That the contracts, in most cases, are completed in one transaction, for good or ill;(b) that, among immediate annuities, there are few withdrawals or alterations;(c) that the rate of mortality, especially among those female lives which form the bulk of our experience, is always diminishing;(d) that this diminishing mortality is to the Companies' disadvantage;(e) that there is nothing which exactly counterbalances (d);(f) that there are no bonus-sharing annuities, so far as I am aware, which can be utilised to exhibit profit or absorb loss.
Privately Administered Pension Schemes
Authors: Brown C. H. L. 
Published: August 2016

Privately administered pension schemes may be divided into 3 main classes:—(1) those which provide pensions based on the salary received by the members.(2) The type known as the “Money-purchase” fund in which each year's contribution is applied as a single premium to purchase an amount of pension at the retiring age.(3) Funds which provide pensions which are fixed in amount in return for a definite contribution which varies according to the age at entry.There are, of course, numerous funds which do not fall exactly into one of these categories—in fact, private funds are usually framed so as to suit the individual needs or preferences of the employers and the members.
Curve Fitting
Authors: Redington F. M. 
Published: August 2016

For the purposes of this paper the term “curve-fitting” is not synonymous with “graduation.” It is restricted to graduation by means of an explicit algebraic or trigonometrical formula: graphic and summation methods are excluded. Even so the subject is unlimited, and this paper cannot provide more than an explanation of a few general principles, and a brief exposition of some of the problems of special interest to the actuary.Our starting point is this: we have decided to fit a curve (vx) to a series of crude figures (ux) and the problems that confront us are:—(a) What formula are we to ascribe to vx?(b) How are we to choose the constants in vx in the best possible way?(c) How are we to test the goodness of fit and to compare the results of different graduations?
Statistical problems of naval aircraft provisioning.
Authors: Beard R. E. 
Published: August 2016

I have been asked to give you some idea of the activities which occupied me for four years of the war, namely, my duties with the Admiralty. For obvious reasons it is not possible for me to give in detail many of my impressions or the problems that arose in the work which was mainly directed to the end of securing the right number of the right type of Naval Aircraft at the right place at the right time. In practice the emergency of the problem precluded the use of sophisticated methods, and recourse had to be made to practical measures designed to provide a fair approximation to the answer sought.As an instance of the actuarial nature of the problem involved it may be noted that the life of an aircraft is made up of three components:(a) a period when, although serviceable, the aircraft is ineffective through being in transit, etc.,(b) a period when it is effective and in use (including that in ‘ready reserve’), and(c) a period when the aircraft is ineffective while undergoing repair, etc.
Single premium for an assurance of the amount outstanding under a Building Society mortgage.
Authors: Gosden H. A. 
Published: August 2016

The accurate calculation of the net single premium at rate of interestifor an assurance to cover the amount outstanding under a Building Society Mortgage subject to a higher rate of interestjis a fairly lengthy process. However, as a fairly heavy contingency loading is usually added, the following simple method gives results sufficiently accurate for most practical purposes.For a loan of initial amount unity repayable overnyears by level annual instalments in arrear the single premium calculated at rate of interestjon a life agexis given by the expressionThe sum assured is payable at the end of the year of death and is equal to the amount of the loan then outstanding before payment of the instalment then due.
A nomogram for calculating extended terms
Authors: Michel J. G. L. 
Published: August 2016

The simplest form of nomogram is a graphical device for representing a functional relationship between three variables in a manner which is often more convenient for practical reference than that of plotting a series of contours for chosen values of one of the three variables on a Cartesian graph. We develop the basis of such a nomogram by means of analytical geometry in this section.The condition that three points (ξ1, η1), (ξ2, η2) and (ξ3, η3) shall be collinear is commonly expressed by means of the determinantIf the relationship between three variablesa, bandcwhich we wish to represent nomographically isF (a,b,c) = o, (2)and we can express (2) in the determinantal form [similar to (1)]wheref1f2(a),f2(b),f3(c),g1(a),g2(b) andg3(c) represent (generally) different functions ofa, bandc, it is apparent that we can associateany three particular values ofa, bandcsatisfying (2) with the pointson a Cartesian graph; and they will be collinear because (3) is of the same form as (1).
The conversion of whole life extras into extra premiums for other classes of assurance.
Authors: Jenkins P.T. 
Published: August 2016

A problem of occasional practical importance is to find the extra premium for a particular class of policy, which corresponds to an extra premium fixed by the Medical Officer for a standard class of policy, here assumed to be whole life. Except when the extra mortality can be assessed by a simple ‘rating up’ of the age of the assured, this problem is not easily solved. The direct calculation of the required extra premium from specially constructed mortality tables would be very laborious, particularly in view of the necessity to reproduce the given whole life extra.In the following note a procedure is developed which provides in the circumstances mentioned and without undue labour, an extra premium for any class of policy once it is decided whether the extra risk is of increasing, constant or decreasing type. A few examples illustrate how the method may be applied in practice.
Female mortality in early life and its effect upon reproductivity
Authors: Pollard A. H. 
Published: August 2016

The gross and net reproduction rates differ only on account of the mortality factor and the difference, at present, is quite appreciable. If we are investigating the possibilities of increased reproductivity we would naturally study the causes of the difference between these rates and the likelihood of that difference reducing and thus increasing the reproductivity. In this paper we will determine the extent to which this difference is caused by mortality in different age groups and mortality due to different causes.In a paper by the present writer (J.I.A.Vol. LXXV, p. 151) the rates of mortality for Australia for different ages and different causes of death were determined. The same material will be used in the present analysis where, assuming constant (1938) fertility and using 1935 mortality, we shall determine the difference between the gross and net reproduction rates and the extent to which this difference results from mortality at different ages and from various causes of death. It should be emphasized here that the many arguments raised against any analysis based on causes of death (transfers between causes, variations in diagnosis, selecting a single cause from multiple causes, etc.) do not apply with much force to the causes of death at the ages that are, in this problem, of most interest.
Estate duty on life policies and annuities
Authors: Houseman David 
Published: August 2016

When I was invited to address the Society on some legal subject of my own choice, it was natural perhaps that my thoughts should go back to my first appearance before the Society some 25 years ago. My subject then was ‘Children's Deferred Assurances’, which was appropriate from a personal point of view—I had just become a proud father! My present subject is ‘Estate Duty’, and I am not asking anyone for aqfactor to show me how appropriate it may be from the same standpoint!It is bold for anyone outside the Estate Duty Office to speak on estate duty; but I have deliberately chosen a dull and uninteresting subject because of its recent added importance to all who are concerned with life policies and annuities. The maximum rate of duty under the Finance Act, 1894, which first imposed it, was 8%. The maximum rate to-day is 80 %. Actuaries and lawyers must clearly do something about it—if they can—for otherwise there will be still less of estates left to be frittered away among the beneficiaries!
Concerning large sample tests and confidence intervals for mortality rates
Authors: Walsh John E. 
Published: August 2016

In reference(1), some large sample significance tests and confidence intervals for mortality rates were presented. These results appear to be valid for the usual type of insurance data. Also, for an ordinary mortality study, application of a test or confidence interval does not require much additional work. This paper presents a review of reference (1) along with a discussion of the concepts involved. More extensive tables of significance tests and confidence intervals are included in this paper.To apply the results of (1), the data must be subdivided according to the first letter of the surname of the person insured. According to present practice, such information is not recorded for a mortality study. Since this recording requires little extra effort at the initial stage of an investigation, however, such information could easily be incorporated into future mortality studies.
Ideas and statistics
Authors: Redington F. M. 
Published: August 2016

I have long wanted to give vent to the thoughts in this talk and therefore I should start by saying ‘Thank you’ for providing me with an audience. Although the broad ideas have been in my mind for a long time, when it came to the point I had considerable difficulty in deciding just what to say and particularly in choosing a suitable title. I am far from satisfied with the somewhat pretentious name with which I have christened the infant, but it does I hope convey the thought that although I shall be talking about statistics—a fact which may or may not be an attraction and was therefore better not concealed—it will not be in a detailed technical sense. Indeed one of my first duties must be to disavow, not only any desire but any considerable ability to expound on statistics in detail.I have reached the age in life when I begin to gain much comfort from the thought that what matters is not the facts you know but the way you think. It is a comforting thought when you have forgotten most of the facts.