bluuebunny/crossref_metadata_2025 huggingface dataset:
LOCAL KEISLER MEASURES AND NIP FORMULAS
Authors: GANNON KYLE
Published: June 2019

We study generically stable measures in the local, NIP context. We show that in this setting, a measure is generically stable if and only if it admits a natural finite approximation.
Repressed productive potential and revolt: insights from an insurgency in Burundi
Authors: Samii Cyrus , West Emily A.
Published: June 2019

The relationship between participation in revolt and individuals' economic conditions is among the most debated in political science. While conventional economic theory suggests that those who face the poorest economic prospects are most inclined to fight, extant evidence is decidedly mixed. We address this puzzling variation by analyzing the interplay between macro-structural conditions and individuals' micro-level circumstances. Under conditions of severe group repression, we show how a “glass-ceiling” logic may operate: among the repressed group, those with relatively high productive potential may be most motivated to revolt. We test this with in-depth analysis of participation in the 1993–2003 Burundian insurgency. The data are consistent with numerous implications of the glass-ceiling logic and inconsistent with extant alternative explanations.
Radiocarbon Dating of the Transition from the Early to the Middle Bronze Age in Northeastern Syria
Authors: Koliński Rafał , Goslar Tomasz
Published: June 2019

The paper presents radiocarbon (14C) dates of samples collected from the Bronze Age cultural strata (VI–II) excavated within Sector P, Tell Arbid, Khabur Triangle, northern Mesopotamia. These strata contain objects (remains of a caravanserai, pits, graves, pottery kilns, and multi-phase houses) representing the periods of Early Jezirah 4-5, and Old Jezirah I-II. 14C dating of these strata was especially important because of a clearly visible period of abandonment of the area at the onset of 2nd millennium BC, recorded on all Khabur Triangle sites studied so far, and because of the questionable reliability of the chronology derived from scarce historical sources. Of the 29 samples of cereal grains, 9 appeared to contain residual material, while Bayesian-analyzed 14C ages of the remaining 20 allowed us to say that, at the turn of the 3rd millennium BC, Tell Arbid was abandoned later than other sites in the area, and that it was occupied over a distinctly longer period during the early 2nd millennium.
The Analogist and Anomalist Controversy
Authors: Colson F. H.
Published: June 2019

The controversy between the Anomalists and Analogists has not, I think, attracted as much of the attention of scholars as it deserves. It was perhaps not a very practical matter, though, as I shall point out presently, it probably had indirectly some important practical results. The interest of the controversy lies rather in the spirit in which it was conducted. Anyone who reads for instance Varro, De Ling. Lat. VIII. 31–32, where the anomalist argues that as in life variety of furniture and the like is necessary for aesthetic enjoyment, so in language anomaly is desirable; or IX. 24, etc., where the analogist argues from the unchanging order that prevails in the heavenly bodies, in the tides, in the continuity of species, will feel that he is moving in a world of thought very different in one way from our own, though in another rather like it. By the analogist language is conceived as a world in itself, much as we conceive of the visible world. Its phenomena are being laid bare and constantly reveal fresh signs of law and order. The investigator sometimes finds facts which prima facie suggest anomaly, but he is as confident that behind them must lie some unifying principle as the scientific man of to-day is with regard to the phenomena of the visible world, as impatient of the suggestion of disorder as he is of any miraculous interference with the order of nature. Even the anomalist, sceptic as he is, approaches the question not in a spirit of mere denial, but of aesthetic consideration. We get a glimpse of a lost point of view. The world of words had a glamour and a wonder for them which it cannot have for us.
On the Meaning of BaΔhn and ΔpomΩi in Greek Historians of the Fifth Century
Authors: How W. W.
Published: June 2019

Since the English author, who has written in the greatest detail and with most acceptance on Greek warfare in the fifth century, has now declared definitely that δρÓμψ cannot mean ‘at the run,’but should be translated both in Thucydides and Herodotus ‘at the quick step’in contrast to βúδην‘at the slow step,’ it may be worth while to re-examine the evidence, and to give some reasons for maintaining the translation ‘at the double’ at least in the descriptions of battles given us by Thucydides, Xenophon, and Herodotus.
On Surrender-Values and the Principles which underlie their Calculation
Authors: Fulford Frederick Wesley
Published: June 2019

The President in his inaugural address last session, expressed the opinion that “the time is ripe for another discussion on surrender-values.” In accordance with that suggestion, I have ventured to bring to your notice some considerations bearing on the subject of surrender-values and the principles which, it would appear, should underlie their calculation.
On a New Interpolation Formula
Authors: Everett J. D.
Published: June 2019

The two leading formulæ at present in use for interpolation by central differences are due to Newton‡ (Methodus Differentialis, Prop. III), though often called by the name of Stirling, who republished them about 20 years later.
The Business Management of Foreign Life Insurance Companies according to German Imperial Law
Authors: Samwer Karl
Published: June 2019

The Paper of Mr. H. R. Harding upon “Government “Legislation in reference to the working of Life Assurance “Companies”, submitted to the First International Congress of Actuaries, the supplement added thereto by myself relative to German Law, and my paper upon German Insurance Legislation for the Second International Congress, show that the public Law relative to the business management of home and foreign Life Insurance Offices differed until recently in the individual German States, and in many of those individual States a firm basis was lacking.
An Enquiry into the Methods and General Principles to be adopted in calculating the Rates of Contribution, or Percentage Deductions from Salary, in the case of Superannuation Funds and Pension Funds generally
Authors: McGowan James
Published: June 2019

A striking indication of the little interest taken by the actuarial profession generally in the subject of Pension Funds is shown by the fact that in the many published volumes of the Journal of the Institute, hardly any information is to be found with reference to such Funds.

This lack of interest in Pension Funds was noticed some time ago by Mr. Ryan (page 470, vol. xxxi, of the Journal), who remarked that “ it was a very curious thing that the important “ question of the valuation of Widows Funds had on no occasion “ been treated by contributors to the proceedings of the Institute. “ In Dr. Sprague's 20-volume Index there was absolutely no “ reference to the question of Widows’ Funds. … He might “ add that the Index to the Journal contained no entry relating “ to superannuation schemes, which was again a matter of great “ public importance.’
On Life Insurance Legislation in Denmark
Authors: Thiele T. N.
Published: June 2019

Life insurance in Denmark has certain peculiarities, which may be interesting perhaps also to foreign actuaries.

In 1871 the Danish Government thought to satisfy all the life insurance necessities of the country by establishing by law, and with the full guarantee of the State, one single institution, “Statsanstalten for Livsforsikring.” By this all legislation with respect to private life insurance was supposed to be rendered superfluous.
The Income Tax as Affecting Life Offices, with special reference to some recent decisions
Authors: Faulks Joseph Ernest
Published: June 2019

“In this world,” said Benjamin Franklin, “nothing is certain but death and taxes”, a remark with which all taxpayers, and not least those responsible for the management of life offices, will feel at the present time in cordial agreement. The great increase in the last few years in the rate of income tax undoubtedly presses very hardly upon the tax-paying community, and it is probably, in part, owing to this increase that there have recently been several cases before the Courts on the subject of the tax, which are not without interest to those engaged in the business of life assurance. To some of these I propose to direct your attention to-night.
“The possible Association of the Consumption of Alcohol with Excessive Mortality from Cancer”
Authors: Newsholme Arthur
Published: June 2019

Part II of Dr. Tatham's decennial supplement to the 55th report of the Registrar-General, published in 1897, contained extremely valuable statistics relating to the relative death-rates and what are known as the “comparative mortality figures” of men engaged in different occupations. These statistics dealt not only with deaths from all causes in conjunction, but also from certain diseases; and the latter figures throw important light upon the influence of occupation on the mortality, for instance, from tuberculosis and cancer.
On Life Premium Book-keeping
Authors: Chatham James
Published: June 2019

The subject to which I invite your attention is one which has never been directly submitted to the Institute of Actuaries, although reference has on various occasions been incidentally made to it. In the discussion which followed the reading of my essay of 1895, to which was awarded the Messenger Prize, it was suggested that I should give a whole set of forms of books necessary for conducting the business of an office, and a classification book for valuation purposes, showing how the information in each would afford a perfect check in the end, and this paper is, to some extent, the outcome of that suggestion. While this is the position of matters in the Institute, it is otherwise with the Faculty, which has now undertaken the functions hitherto performed by the Actuarial Society of Edinburgh. There the subject has frequently been brought before them, more particularly by Mr. McLauchlan, and, on the last occasion, reference was made to the suggestion I have referred to, and it was added that it was a point to which attention might profitably be given. In these circumstances, I do not offer any apology for bringing the matter before you, but I shall not attempt, on this occasion, to give a whole set of forms of books. I shall confine my remarks chiefly to premiums, as I think that in this way the paper will be more easily followed, while it will be possible, within this compass, to show the application of the various checks by means of the Valuation Books described in my essay.
On Staff Pension Funds
Authors: King George
Published: June 2019

The present effort does not profess to be complete. It deals with the main problems that come before the Consulting Actuary in connection with Staff Pension Funds, but does not go into the details of what may be called the fancy benefits which are occasionally met with. The solutions of the general problems here given will, however, indicate the methods to be applied in attacking other, and sometimes more complex, questions, which, when the principles have been grasped, will not present serious difficulty.
Notes on an approximate Method of Valuation of Whole-Life Assurances, with Allowance for Selection
Authors: Ackland Thomas G.
Published: June 2019

The object of the following notes is to state somewhat more fully and formally a method (first published in the Insurance Record for 10 March 1905) of approximating to the reserves required for whole-life assurances, with due regard to the influence of selection; and to illustrate the practical application of the method.
On a form of Spurious Selection which may arise when Mortality Tables are amalgamated
Authors: Elderton W. Palin
Published: June 2019

It is probable that some of the points I venture to bring forward have already suggested themselves to other students, but in view of the interest at present attaching to selection, it seems an opportune time for putting forward any considerations that may help to throw light on a somewhat complicated subject.
On the Relation between the Theories of Compound Interest and Life Contingencies
Authors: Allen John Mayhew
Published: June 2019

It has often occurred to me that but scant justice has been done to the application of the infinitesimal calculus to the theories of compound interest and life contingencies. This is, perhaps, in some measure due to the popular relegation of the differential and integral calculus to the realms of the so-called “higher mathematics.” There are, of course, two aspects of the case to be borne in mind. On the one hand, it is necessary to present the subjects in such a form as will be best suited to the student who is commencing to study them. For this purpose experience shows that a start should be made with particular cases, leaving the generalization until such time as the student shall have obtained a grasp of first principles sufficient to enable him to view the subjects in their general aspect. On the other hand, however, there is no doubt that to the reflective mind there comes a time when the desire is felt to invert the process and deduce the formulæ in their logical sequence from a fundamental general hypothesis.
On Extra Premiums
Authors: Lutt Harold Edward William
Published: June 2019

The question of the premiums which should be charged to meet the eases of lives proposed for assurance admittedly incurring, or about to incur, risks more hazardous than those of the ordinary assured life, has from time to time engaged the attention of the Institute.

More stress has, perhaps, been laid upon the mortality of persons living in tropical countries, where the conditions of life are very different from those to which we are here accustomed, and statistics, obtained either from official sources or from business experience, have been furnished; whilst the only occupations to which attention has been directed are the Naval, Military, and Mercantile Marine Services, and those connected with the sale of alcohol.

With the view of obtaining, if possible, information respecting the modern practice of Life Assurance in connection with extra risks, I ventured to address to all the larger offices a Schedule intended to elicit such replies as would enable me to present a general idea of the methods applied to these cases.

In this I hope I have partially succeeded, but I need not add that the information must be regarded in a very general light. Many offices were particular to point out that, in the absence of any ascertained experience, each case of this nature would be considered upon its individual merits, and rated accordingly.
Some points of interest in the operations of Friendly Societies, Railway Benefit Societies and Collecting Societies
Authors: Watson Alfred W.
Published: June 2019

Nearly twenty-two years have elapsed since the masterly essay of our President gave to the institute an opportunity for comprehensive examination of the British friendly society system. During the intervening period, phases of the subject have been occasionally before the Institute, but the period has been one of great activity amongst the friendly societies, and developments of interest to actuaries culminating, it may be suggested, in the co-operation of the State and the societies proposed by the Chancellor of the Exchequer, have emerged. In the circumstances it has seemed to me that the Institute might again survey this wide field of provident effort with interest to its members and profit to the community.

I propose accordingly to examine the more important groups of societies, paying particular regard in respect of the leading affiliated orders to the machinery by which it is sought to equip the constituent parts for the effective recognition of their duties; thence passing to some questions of special interest to ourselves. For the purpose of connected description it will be necessary to mention particular organizations, but I trust that nothing of what I have written may seem to depart from the excellent custom of neutrality which governs our debates. I venture indeed to say that so far from being unduly sensitive, all the societies which are striving for improvement (and I think this may be said of most of them) are receptive towards the stimulus of informed criticism.
Some Notes on the Establishment of the Office of Public Trustee in England
Authors: Sharman William Charles
Published: June 2019

In bringing these Notes under the consideration of the members I feel some apology is needed for the reason that the subject may he said to be somewhat outside the scope of the ordinary proceedings of the Institute.

In addition, however, to its legal aspects, which will doubtless appeal to a profession which demands from its members a not inconsiderable knowledge of law, I venture to think there are other grounds on which the subject may be considered suitable for discussion.

The Public Trustee Act brings into being a Department, which, from its intimate connection with the affairs of the people and the large financial interests involved, may in course of time rank only second to some of the great Departments of the State, and, from this point of view alone, the subject is of interest.

Moreover, it has a close connection with the work of many Actuaries owing to the large investments made by Life Offices in reversionary securities, this kind of investment being peculiarly affected by questions concerning the trusteeship.

When, further, it is remembered that Insurance Companies form one of the classes of Corporate Bodies which may be authorized by the Treasury and Public Trustee to undertake the duties of Custodian Trustees, I think it will be admitted that the subject is one with which we are practically concerned.
I.—On the Valuation of the Payment on the Death of a Pensioner of the excess of his Contributions, with or without interest, over his pension payments and II.—On a Method of scheduling particulars for the Valuation, in certain cases, of prospective Pensions based on terminal Salaries
Authors: Tinner Thomas
Published: June 2019

In many staff pension funds there is a provision that if a pensioner dies before his pension payments amount to the oaccumulation of his contributions (with or without compound interest) to the date of retirement, the difference shall be paid to his representatives.

Although Mr. H. W. Manly and Mr. George King have dealt with the problèm of valuing this benefit, and Mr. Manly has shown how to calculate the rate of contribution to provide for it, the formulas presently to be deduced may be thought of sufficient interest to warrant their publication.

In considering the benefit mentioned above, it will be seen that if—

(i) the contributions amount to n times the yearly pension,

(ii) the annuity used in valuing the pension be continuous,

(iii) the benefit be valued on the assumption that the funds earn no interest—

the value of the benefit at the date of retirement, for each unit of annual pension, will be as follows, assuming the deaths to be equally distributed over the year:

Of lx persons retiring at age x, dx will die in the year of age x to x + 1, and as they will, on the average, die in the middle of the year, there will be payable in respect of them (n − ½)dx, being the amount of their contributions less ½dx which they will have received as pension.
Notes on the Insurance Act 1910, Dominion of Canada
Authors: Bradshaw Thomas
Published: June 2019

In view of the long and honourable association of British life assurance institutions with life assurance in Canada, an association dating back prior to the formation of Canada's oldest company, and of the deep interest taken and aid rendered during the preparation of the Dominion Insurance Act, 1910, by the Canadian and Home officers of those British life institutions actively engaged in business in Canada, as well as by leadingindependent British actuaries, it would appear but appropriate that some reference should be made in the proceedings of the Institute relative to the new Act. Furthermore, in consequence of the increased interest taken in the affairs of Canada generally, and of the great development everywhere in evidence there, may it not be that a closer acquaintance with the principles underlying the new Canadian legislation may encourage those British life offices which though nominally having agencies in Canada are inactive in so far as new business is concerned, and other offices which have not yet ventured across the ocean, to seek aggressively for new business throughout the Dominion.
Notes on the Construction of Mortality Tables
Authors: Elderton W. Palin , Fippard Richard C.
Published: June 2019

The following notes are an attempt to show

(1) How select and aggregate rates of mortality can be found from insurance office data by the methods at present used to find rates of mortality from censuses and the records of deaths among the general population, and

(2)How the census method can be modified in the case of a prolonged investigation to give a continuous mortality investigation.

We have also tried to deal with a few of the objections to the method, and some of the practical points that arise in its application.
“House Purchase” Companies: The “Bond Investment” Sections of the 1909 Act and Some Actuarial Features of the Business Returned Thereunder
Authors: Maltby Charles Hugh
Published: June 2019

In putting forward the present Paper I am somewhat dubious as to whether it is not almost necessary to apologise for bringing before the notice of the Institute a subject which forms but one of the many minor branches of our Science, and which, moreover, has had a certain amount of odium—much of which is undeserved—thrown upon it from time to time. So far, however, as the Institute is concerned, it is practically untrodden ground, and the consideration, therefore, of some of the new problems suggested by it may not be without interest.
Approximate Valuation of Endowment Assurances
Authors: Elderton W. Palin
Published: June 2019

In the discussion that followed the reading of a paper before the Institute of Actuaries Students’ Society, by E. A. Woodall on the valuation of special policies, F. Bedford explained that certain classes, such as joint life endowment assurances, could be valued conveniently by assuming that all the policies will mature at the same age, and calculating the net premium on the same assumption. This method is mentioned in the Students’ Journal, vol. I, No. 2, pp. 24–26, where Mr. Woodall, in giving the method in the abstract of his paper and the discussion, explains how the method applies to certain classes, and writes : “Since the reserve for an endowment assurance maturing at “70 or 75 is practically the same as the reserve for an endowment “assurance of the same term maturing at 50, 55, 60, or 65, the “error of 10 years in the equivalent age is of little importance,” “provided the net premium is calculated on the same assumptions.” This quotation may be taken as the text for the present paper, which discusses the application of the method to ordinary endowment assurances and the errors involved in its use.
Section 72 of the National Insurance Act. Some other Features of Friendly Societies and National Insurance, including a Note on the Proposed Belgian National Insurance Act
Authors: Nathan Eric B.
Published: June 2019

In the discussion on Mr. Simmonds's Paper (J.I.A., vol. xlvii) allusion was made by several speakers to the omission of any reference in that Paper to Section 72 of the National Insurance Act. The omission was, I understand, intentional. Mr. Watson devoted his sixth Lecture on Friendly Society Finance to this Section and to Section 73. He dealt very fully with the position as it then existed. Any present reference to the Section can only follow the lines he laid down, and may therefore appear superfluous. As, however, there was no opportunity of discussing this subject on the Lecture, and as in the discussion following Mr. Simmonds's Paper there appeared a certain interest in this Section, it seems probable that a short demonstration of this side of the National Insurance Act may lead to an interesting and useful discussion, notwithstanding the failings in the Paper itself.
The Analysis of Life Office Expenses
Authors: Maltby Charles Hugh
Published: June 2019

In turning over the pages of the Journal, one is struck by the number of papers which would have been rendered far more valuable if more detailed data of the actual expenses of management had been available. Probably less is known about expenses than about any other factor involved in our daily actuarial work; and this comparative ignorance is the more remarkable when we remember the immense amount of thought and research which has been expended on the subjects of Mortality and Interest.

Perhaps good reasons existed in the past for this comparative neglect; but it appears to me that the time is approaching—if it has not already arrived—when it will be absolutely necessary to investigate the subject of expenses to the fullest possible extent. To mention only one aspect of the subject, there is a general impression that expenses are tending to increase, and hence it becomes important for each office to ascertain whether this impression is correct in its own case, and if so, the causes of the increase. These questions can only be answered by a full analysis; but if this is possible any increase will be robbed of much of its force, even if its cause cannot be removed. Certainly expenses are at least as worthy of investigation as mortality, and will probably yield more valuable results, since they, at least, are susceptible of regulation.
Presidential Address on the Theory of Proportion
Authors: Hill M. J. M.
Published: June 2019

In the second edition of my Contents of the Fifth and Sixth Books of Euclid I have taken the ideas stated in the preceding article as my starting point, and built up the conditions involved in the 5th and 7th definitions in the following way:

1.

The ratio of a magnitude A to another magnitude B of the same kind is a real number, rational or irrational, determined in the manner explained in what follows. It is denoted by the symbol A : B.

2.

If the magnitudes A and B have a common measure G, so that A = aG, B = bG, where a, b are positive whole numbers, then A : B is defined to be the rational number .
Inoculation of Dogs with the Parasite of Kala Azar (Herpetomonas [Leishmania] donovani) with some Remarks on the Genus Herpetomonas
Authors: Patton W. S.
Published: June 2019

Since the discovery of the parasite Kala Azar by Lt.-Col. Leishman, R.A.M.C., a number of investigators have endeavoured to reproduce the disease in the lower animals but without success. The recent discovery of Nicolle that dogs are susceptible to an allied human parasite (Herpetomonas infantum) has added a fresh stimulus to work along these lines, and in order to see whether the dog can be infected with H. donovani I carried out some inovulation experiments, which I propose recording in this paper.
II. Suggestions for a Complete Edition of the Jami‘u’t-Tawarikh of Rashidu'd-Din Fadlu'llah
Authors: Browne Edward G.
Published: June 2019

The Jámi‘u’t-Tawáríkh is unquestionably one of the most important historical works in the Persian language, not only by reason of the singularly full and authentic account of the history and antiquities of the Mongols for which it is chiefly celebrated, but also by virtue of the general history, especially the history of the independent or semi-independent post-Muhammadan dynasties which held sway in Persia immediately before the rise of the Mongol dominion (i.e. between the ninth or tenth and the thirteenth centuries of the Christian era), wherewith the author, Rashídu'd-Dín Faḍlu'lláh, or ‘Rashíd the physician’ as he sometimes calls himself, supplemented his original work.
VI.—Theorems relating to a Generalisation of the Bessel-Function
Authors: Jackson F. H.
Published: June 2019

In this paper, theorems which are extensions of the following, are discussed:—

We define J[n] (λ, x) as

In this expression
The Starting Methods of Aëroplanes
Authors: Weiss José
Published: June 2019

The heaviest flying birds known scarcely reach one quarter of the weight of an average man, and it can be said that one of the most probable causes of the absence in Nature of heavier varieties is the fact that although such birds could fly easily enough, once on tlie wing, they would be unable to leave the ground, owing to’ the enormity of the power the first lift Avould require. The larger and heavier the bird, the less, in relation to its weight, is the power developed in flight, but, on the other hand, the greater is the eft'ort. needed for a. lift from the ground. I do not wish to enlarge upon this question, which has been treated by various authors, and only refer to it because it embodies a principle which we must bear in mind when considering the means of starting flight, namely, that the difference between the power required respectively for the flight and for the start becomes greater as the apparatus increases in weight.
FINDING NONSTATIONARY STATE PROBABILITIES OF OPEN MARKOV NETWORKS WITH MULTIPLE CLASSES OF CUSTOMERS AND VARIOUS FEATURES
Authors: Matalytski Mikhail , Kopats Dmitry
Published: June 2019

This paper discusses a system of difference-differential equations (DDE) that is satisfied by the time-dependent state probabilities of open Markov queueing networks with various features. The number of network states in this case and the number of equations in this system is infinite. Flows of customers arriving at the network are a simple and independent, the time of customer services is exponentially distributed. The intensities of transitions between the network states are deterministic functions depending on its states.

To solve the system of DDE, we propose a modified method of successive approximations, combined with the method of series. The convergence of successive approximations with time to a stationary probability distribution, the form of which is indicated in the paper has been proved. The sequence of approximations converges to a unique solution of the system of equations. Any successive approximation can be represented as a convergent power series with an infinite radius of convergence, the coefficients of which satisfy recurrence relations, which is convenient for calculations on a computer. Examples of the analysis of Markov G-networks with various features have been presented.
Conditional Effects of Lifetime Alcohol Consumption on Methamphetamine-Associated Neurocognitive Performance
Authors: Saloner Rowan , Paolillo Emily W. , Umlauf Anya , Moore David J. , Heaton Robert K. , Grant Igor , Cherner Mariana ,   The TMARC Group
Published: June 2019

Objectives:

Methamphetamine (MA) dependence contributes to neurotoxicity and neurocognitive deficits. Although combined alcohol and MA misuse is common, how alcohol consumption relates to neurocognitive performance among MA users remains unclear. We hypothesized that alcohol and MA use would synergistically diminish neurocognitive functioning, such that greater reported alcohol consumption would exert larger negative effects on neurocognition among MA-dependent individuals compared to MA-nonusing persons.

Methods:

Eighty-seven MA-dependent (MA+) and 114 MA-nonusing (MA−) adults underwent neuropsychological and substance use assessments. Linear and logistic regressions examined the interaction between MA status and lifetime average drinks per drinking day on demographically corrected global neurocognitive T scores and impairment rates, controlling for recent alcohol use, lifetime cannabis use, WRAT reading performance, and lifetime depression.

Results:

MA+ displayed moderately higher rates of impairment and lower T scores compared to MA−. Lifetime alcohol use significantly interacted with MA status to predict global impairment (ORR = 0.70, p = .003) such that greater lifetime alcohol use increased likelihood of impairment in MA−, but decreased likelihood of impairment in MA+. Greater lifetime alcohol use predicted poorer global T scores among MA− (b = −0.44, p = .030) but not MA+ (b = 0.08, p = .586).

Conclusions:

Contrary to expectations, greater lifetime alcohol use related to reduced risk of neurocognitive impairment among MA users. Findings are supported by prior research identifying neurobiological mechanisms by which alcohol may attenuate stimulant-driven vasoconstriction and brain thermotoxicity. Replication and examination of neurophysiologic mechanisms underlying alcohol use in the context of MA dependence are warranted to elucidate whether alcohol confers a degree of neuroprotection.
Attitudes and perceptions among urban South Africans towards sugar-sweetened beverages and taxation
Authors: Bosire Edna N , Stacey Nicholas , Mukoma Gudani , Tugendhaft Aviva , Hofman Karen , Norris Shane A
Published: June 2019

Objective:

A tax on sugar-sweetened beverages (SSB) was introduced in South Africa in April 2018. Our objective was to document perceptions and attitudes among urban South Africans living in Soweto on factors that contribute to their SSB intake and on South Africa’s use of a tax to reduce SSB consumption.

Design:

We conducted six focus group discussions using a semi-structured guide.

Setting:

The study was conducted in Soweto, Johannesburg, South Africa, 3 months before South Africa’s SSB tax was implemented.

Participants:

Adults aged 18 years or above living in Soweto (n 57).

Results:

Participants reported frequent SSB consumption and attributed this to habit, addiction, advertising and wide accessibility of SSB. Most of the participants were not aware of the proposed SSB tax; when made aware of the tax, their responses included both beliefs that it would and would not result in reduced SSB intake. However, participants indicated cynicism with regard to the government’s stated motivation in introducing the tax for health rather than revenue reasons.

Conclusions:

While an SSB tax is a policy tool that could be used with other strategies to reduce people’s high level of SSB consumption in Soweto, our findings suggest a need to complement the SSB tax with a multipronged behaviour change strategy. This strategy could include both environmental and individual levers to reduce SSB consumption and its associated risks.
The Measurement of Wind Velocity
Authors: Melvill Jones B. , Booth Harris
Published: June 2019

The essential points of any anemometer are that it should be correctly calibrated and should read accurately over the whole range through which it is to be used, and that the calibration should not alter with time. The actual calibration of an anemometer by a direct comparison of its readings with its rate of movement through the air is a matter of very great difficulty, and the various methods by which it has been done will be considered later, but when it has once been cairied out for one anemometer all others can be easily calibrated from that one by comparison.
Helicoptere v. Aeroplane
Authors: Chatley H.
Published: June 2019

Ever and again in the history of aëronautical development during the last century there occurred a movement in favour of the hélicoptère or vertical screw machine, and now when flying machines have advanced to a practical stage the question again appears. Many will have doubtless followed with interest the series of letters which has been appearing in “Engineering” since early in the year, in the course of which several engineers of repute have advocated the hélicoptère in no uncertain manner.
On the Flying Fish
Authors: Shadbolt L.
Published: June 2019

I have been requested to write a short paper on the flight of the flying fish and the lessons which this act may afford in the steering and management of an aëroplane in flight.

As yet we are still striving to attain success in aërial flight by means of a machine heavier than air. Many remarkable flights have been recorded quite recently, and the art of aviation has advanced during the past few months by leaps and bounds. It now appears clear that under favourable conditions, still air, or with but a moderate wind and an open course, an aëroplane may be constructed, or soon will be, which can remain in the air as long as the motive power which drives the propeller is maintained, or practically as long as the supply of petrol capable of being carried holds out.
The Laws of Air Screws: I.–The Screw Without Axial Motion
Authors: Turnbull W. R.
Published: June 2019

In the design of aeroplanes, I have been constantly hampered by lack of reliable formulaæ that would give the thrust and horse-power required for a given diameter, pitch, speed, etc., of screws. The theoretical formulæ are too complex and uncertain for concrete computations, so I have undertaken an experimental study of air screws and have endeavoured to deduce formulæ, from the experimental data, which shall be reliable and at the same time cover the complexities that must enter with screws of widely differing elements such as blade area, form, pitch, etc.

M. S. Drzewiecki, in his excellent theoretical study of Air Screws, says “the question of screws in general is very complex, and poorly enough understood from a theoretical standpoint,” and we might add it is almost equally complex and little understood from the practical and experimental standpoint.
Notes on the Present Position of Mechanical Flight in France
Authors: Lloyd Herbert F.
Published: June 2019

For more than a century past the problem of human flight by means of heavier-than-air machines appears to have exercised a strong fascination on the minds of French inventors and engineers, and since November, 1906, as the result of Santos Dumont's classic experiments, and more recently the longer successful flights of Henri Farman and Léon Delagrange, even the general public has become interested in the subject, and has at last been taught to realise that dynamic flight is not only a possibility, but a fact, and that with each day which passes the success already attained is being steadily carried another step forward towards the evolution of the eventual type of perfected machine.

If we except the performances of the Brothers Wright in America, it is admitted that France has led, and is still leading, the aeronautical progress of the world, and it is not difficult to understand why this should be the case.
Stability of Aëroplane Support for Flying Machines
Authors: Wenham F. H.
Published: June 2019

The earliest attempts at flights by man have been by extended wings in imitation of those of bats or birds, all of which have ended with failure, or fatal accidents.

The bird-wing type for supporting a man and mechanism in air must extend at least 60 feet from end to end, and be very light and strong, for carrying the weight—an impracticable construction. All this is fully explained in a paper read by me in 1866 at the first meeting of the Aeronautical Society of Great Britain, of which I was the pioneer.

Perceiving that a single pair of far- extended wings was impossible for man flight, I evaded lateral extension by placing a system of five aëroplanes, or webs, above each other. The upper one slightly in advance.
The Aerodynamic Resistance of Bars, Struts and Wires—III
Authors: Thurston A. P.
Published: June 2019

The aerodynamic resistance of wires. The apparatus used in these experiments was described by the author in his f Report to the Laboratory Committee of the Aeronautical Society of Great Britain. When the experiments herein described were started in 1910 no information on the resistance of wires and ropes was available, but the following papers have since been published :— “ The Resistance of Wires and Ropes in a Current of Air,” by B. Melville Jones, B.A. ; “ Comparison of the Resistances of Stationary and Vibrating Wires,” by T. E. Stanton, D.Sc, M.I.C.E. (Report of the Advisory Committee for Aeronautics, 1910-11) ; and “ The Tests of Smooth Wires and Wire-ropes made at the Gottingen “ Modellversuchsanstalt “ (Ztsch. fur Flugtechnik und Motorluftschiffahrt, Oct. 29th, 1910). Owing to the absence of funds the experiments of the resistance of wires have not been carried to a conclusion. The following data and conclusions are derived from a series of preliminary or trial experiments. They are published herewith for the guidance of future experimenters.
The Aerodynamic Resistance of Bars, Struts and Wires-IV
Authors: Thurston A. P.
Published: June 2019

The shielding effects of struts and bars. In the previous communications, I., II., and III., the aerodynamic resistance of single bars, struts, and wires was investigated. The object of the investigation herein described was to determine the shielding effect of one bar mounted in the direct path of another bar of identical length, shape, and size.

Method of mounting the specimens. The upper bar was suspended from the fork of the balance at two points 6 inches apart in the manner described in communication II., and the identical lower bar was pivoted to the upper bar by two parallel wires 6 inches apart. Means were provided to allow the lower bar to be gradually lowered away from the upper bar. The axis of the bars were kept parallel and the ends of the two bars were kept exactly beneath one another throughout the experiments. All the bars were 24 inches long and $ inch thick.
Modeling the Impacts of Urbanization on Summer Thermal Comfort: The Role of Urban Land Use and Anthropogenic Heat
Authors: Yang Ben , Yang Xuchao , Leung L. Ruby , Zhong Shiyuan , Qian Yun , Zhao Chun , Chen Feng , Zhang Yaocun , Qi Jiaguo
Published: June 2019

Urban land use and anthropogenic heat (AH) emission can considerably influence the human thermal comfort during extreme heat events. In this study, a spatially heterogeneous AH emission data and updated urban land use data are integrated into the Weather Research and Forecasting model to simulate the physical processes of urban warming during summer. Simulations conducted in the Yangtze River Delta (YRD) of east China suggest that the mean urban heat island intensity reaches 1.49 °C in urbanized areas during summer, with AH emission making a considerable contribution. The warming effect due to urban land use is intensified during extremely hot days, but in contrast, the AH effects are slightly reduced. Urban development increases the total thermal discomfort hours by 27% in the urban areas of YRD, with AH and urban land use contributing nearly equal amount. By limiting the daytime latent heat release, urban land use reduces the daily maximum heat stress particularly during extremely hot days; however, such alleviations can be offset by the AH emission. Strategies for mitigation of urban heat island effect and heat stress in cities should therefore include measures to reduce AH emission.
Sensitivity of Hail Precipitation to Ensembles of Uncertainties of Representative Initial Environmental Conditions From ECMWF
Authors: Li Xiaofei , Zhang Fuqing , Zhang Qinghong , Kumjian Matthew R.
Published: June 2019

The sensitivity of hail precipitation from an idealized hailstorm to realistic environmental uncertainties was investigated through ensembles of cloud‐resolving simulations using the Weather Research and Forecasting model, with initial condition perturbations derived from the European Centre for Medium‐Range Weather Forecasting (ECMWF) operational ensemble. The analyses revealed that hail precipitation rate was very sensitive to small initial environmental perturbations, particularly in thermodynamic variables. The hail precipitation rate was significantly positively correlated with perturbations to the initial potential temperature below 750 hPa and to water vapor mixing ratio above 750 hPa. These small initial perturbations led to subsequent substantial differences in hail precipitation as well as in characteristics of the parent storm (e.g., updraft velocity, diabatic heating, and microphysical processes), all of which play a key role in hail growth. The larger sensitivity of hail precipitation to thermodynamic rather than kinematic environmental initial condition perturbations persisted even when the magnitude of the perturbations was reduced to 10% of the realistic uncertainties derived from the ECMWF ensemble. In the ensemble with reduced‐amplitude initial perturbations, there was still a moderately strong positive correlation between hail precipitation rate and the initial perturbations of the thermodynamic variables. However, these sensitivities were nonlinear, suggesting that the intrinsic predictability of hail precipitation rate may be limited, even when environmental uncertainties are reduced to 10%, 1.0 × 10−3, and 1.0 × 10−5 of the currently realistic magnitude of initial condition uncertainty.
A 5.3‐Million‐Year History of Monsoonal Precipitation in Northwestern Australia
Authors: Stuut Jan‐Berend W. , De Deckker Patrick , Saavedra‐Pellitero Mariem , Bassinot Franck , Drury Anna Joy , Walczak Maureen H. , Nagashima Kana , Murayama Masafumi
Published: June 2019

New proxy records from deep‐sea sediment cores from the northwestern continental margin of Western Australian reveal a 5.3 million year (Ma) history of aridity and tropical monsoon activity in northwestern Australia. Following the warm and dry early Pliocene (~5.3 Ma), the northwestern Australian continent experienced a gradual increase in humidity peaking at about 3.8 Ma with higher than present‐day rainfall. Between 3.8 and about 2.8 Ma, climate became progressively more arid with more rainfall variability. Coinciding with the onset of the Northern Hemisphere glaciations and the intensification of the Northern Hemisphere monsoon, aridity continued to increase overall from 2.8 Ma until today, with greater variance in precipitation and an increased frequency of large rainfall events. We associate the observed large‐scale fluctuations in Australian aridity with variations in Indian Ocean sea surface temperatures, which largely control the monsoonal precipitation in northwestern Australia.
Months‐Long Subduction Slow Slip Events Avoid the Stress Shadows of Seismic Asperities
Authors: Rousset Baptiste
Published: June 2019

With precise geodetic measurements, slow transient fault slip events with durations from days to years have been documented at subduction zones for two decades. Long‐lasting transient events with durations longer than 100 days occur at the downdip edge of seismogenic zones. With such long durations, only a few events have been documented so far. Takagi et al. (2019, https://doi.org/10.1029/2018JB016738) propose a new methodology to detect these events and successfully apply it to the Nankai subduction zone in which they characterize 24 events, including 11 new detections. Combined with other observations from around the Pacific rim, they suggest that the lateral segmentation of long‐lasting slow slip events is controlled by the location of seismic asperities associated with their stress shadows.