bluuebunny/crossref_metadata_2025_split huggingface dataset:
The tropics: cradle, museum or casino? A dynamic null model for latitudinal gradients of species diversity
Authors: Arita Héctor T. , Vázquez‐Domínguez Ella 
Published: April 2008

AbstractSeveral ecological and evolutionary hypotheses have been proposed to explain the latitudinal diversity gradient (LDG), but a general model for this conspicuous pattern remains elusive. Mid‐domain effect (MDE) models generate gradients of species diversity by randomly placing the geographic ranges of species in one‐ or two‐dimensional spaces, thus excluding both evolutionary processes and the effect of contemporary climate. Traditional MDE models are statistical and static because they determine the size of ranges either randomly or based on empirical frequency distributions. Here we present a simple dynamic null model for the LDG that simulates stochastic processes of range shifts, extinction and speciation. The model predicts higher species diversity and higher extinction and speciation rates in the tropics, and a strong influence of range movements in shaping the LDG. These null expectations should be taken into consideration in studies aimed at understanding the many factors that generate latitudinal diversity gradients.
Mechanical bowel preparation and antibiotic prophylaxis in colorectal surgery: use by and opinions of Spanish surgeons
Authors: Roig J. V. , García‐Fadrique A. , García‐Armengol J. , Bruna M. , Redondo C. , García‐Coret M. J. , Albors P. 
Published: April 2008

AbstractObjective  Antibiotic prophylaxis (AP) and mechanical bowel preparation (MBP) previous to surgery have classically been regarded as important in colorectal surgery. The latter has recently been questioned. We evaluated opinion of Spanish surgeons about the use of these measures.Method  E‐mail survey among all members of Spanish Coloproctologic Associations.Results  Of 413 participants in the survey, 131 (31.7%) responded; 87% of surgeons used cathartics (70%), enemas (2%) or both (28%) for MBP. MBP was used 60% in right colon surgery, 90% in left colon and 99% in rectal surgery. Surgeons with more case load or those who specialized in colorectal surgery used significantly less MBP; 60% of the surgeons thought that MBP made surgery easier and reduced contamination; 35% thought that it decreased wound infection (WI) and 17% thought that it prevented anastomotic leaks. For 77%, it was regarded as useful or very useful. AP was used by 99.3% of surgeons including systemic alone in 86.2% and combined with oral in 16.8%. The first dose was given 2 h before surgery by 20.2% of the surgeons, at the anaesthetic induction by 78.3% and postoperatively by 1.5%; 43% used single dose only, 44.5% extended to 24 h and 12.5% for two or more days; 95% thought that AP reduced WI and 96% considered that it was useful.Conclusion  There is general agreement on AP. MBP remained a common practice among Spanish colorectal surgeons except for right colonic resection. Surgeons with more case load and specialization used it significantly less.
Relational Aggression in Peer and Dating Relationships: Links to Psychological and Behavioral Adjustment
Authors: Ellis Wendy E. , Crooks Claire V. , Wolfe David A. 
Published: April 2008

AbstractWe examined the contribution of relational aggression in adolescents’ peer and dating relationships to their psychological and behavioral adjustment. In the Fall and again four months later, 1279 (646 female) grade 9 students reported on relational aggression perpetration and victimization in their romantic and peer relationships, depression/anxiety symptoms (psychological adjustment) and delinquency (behavioral adjustment). Using hierarchical regression analyses, controlling for Time 1 adjustment/behavior, peer relational aggression perpetration predicted depression/anxiety. Dating relational victimization also predicted depression/anxiety, but only for girls. Furthermore, girls who were perpetrators of relational aggression in both peer and dating contexts were most likely to show increases in delinquent behavior. We conclude that dating and peer relationships are not redundant, but make independent and additive contributions to adolescent adjustment. Girls, in particular, may be at greatest risk for poor outcomes when they have relationally aggressive relationships. Results also highlight the need for greater awareness of the complexity and significance of adolescent dating relationships.
Mothers' Cognitions about Children's Self‐control: Implications for Mothers' Responses to Children's Helplessness
Authors: Moorman Elizabeth A. , Pomerantz Eva M. 
Published: April 2008

AbstractThis research examined the role of mothers' cognitions about children's self‐control in their responses to children's helplessness. Mothers and their four‐year‐old children (N = 109) were asked to work on a difficult task in the laboratory. Mothers' hostility and warmth as well as children's helpless (vs. mastery) behavior were coded every minute. Mothers also completed a set of questionnaires assessing their cognitions about children's self‐control. Hierarchical linear modeling indicated variability among mothers in their minute‐to‐minute hostility, but not warmth, in response to children's helplessness. Mothers' cognitions contributed to this variability: The more mothers placed importance on, worried about, and believed they could influence their children's self‐control, the more hostility they demonstrated following their children's helplessness.
Eenvoudige mathode voor het interpreteeren van statistisch contröle‐materiaal
Authors: de Jong A. J. 
Published: April 2008

SummaryA simplified method for the working out of statistical control data by means of a suitable abacus is described and explained. A practical example for a population corresponding to the Normal (Gaussian) Curve is given. This method can also be applied to Frequency Distributions not obeying the Law of Gauss, provided they can be represented by a known mathematical function.A simplified method for the compilation of statistical data concerning weights by means of a balance provided with numerators, is described.The possibility of the application of a system of numerators to automatic dosing machines is discussed, by means of which control, based on random sampling, could be replaced by weighing dosages individually.
Constructie van kansellipsen in een correlatiediagram
Authors: Hekker Ir Th. 
Published: April 2008

Summary  (Construction of chance ellipses in a correlation diagram).Chance ellipses in a correlation diagram are calculated from the formula of the normal correlation surface (the chance ellips P contains the area of the correlation diagram, where P% of the observations are found). The construction of these ellipses is explicated. A table with factors to construct the ellipses for different values of P is added.
De bewerking van veldproeven volgens de methode van Knut Vik
Authors: Stoffels Ir A. 
Published: April 2008

Summary  (The treatment of field experiments by Knut Vik's method).Agriculturists and statisticians have studied the problem, how to free the yields in a field experiment from the inequality of the soil. The method of the analysis of variance, due to the English statistician R. A. Fisher has taken an important place in the study of field experiments, so that other methods fell in the background.The Norwegian agriculturist Knut Vik has suggested a method, which leads to good results without complicated calculations and without the knowledge of a great part of the mathematical statistics.The mathematical foundation of this method is discussed in this article, which concludes, that the method of Knut Vik is of great importance for agriculturists, who don't want to perform intricate calculations.
Het quantitatieve verband tussen dosering en letaliteit bij proefdieren
Authors: Nass Drs C. A. G. 
Published: April 2008

Summary  (On the quantal response of animals to drugs).The methods of Bliss (6) and Fisher to deal with dosage mortality data were explained till the computation of the final regression line, which will be treated in a following article. These methods are based on the tacit assumption that the dosage mortality data do follow a constant probality distribution. This is not always true. In the cases of t.b.‐infected Cavias (7) and the convulsive effect of insuline to mice (4) the experiments are irreproducible and so a factor F must exist, which varies in an unknown and irregular way between the series. It is still possible then, to draw trustable inference relative to, say, two different preparations A and B of the drug, by mixing up the two series completely at random, safe for the difference between A and B. In this way F is degraded to an ordinary random variable and the analysis may be executed, as far as the difference goes, as if F were nonexistent.The logarithmic distribution of the susceptibility to drugs may be taken as een instance of a wider rule, which embraces also the facts collected in the law of Weber—Fechner and ought to be called the Rule of Galton: In biology the logarithmic progressions are predominant to the arithmitic ones. That the logarithmic progressions are peculiarly obvious in the cases of susceptibility to drugs or to sensual stimuli, is due to the fact that here the range of variability is relatively large. Apparently the change of scales takes place at the very moment in which the physico‐physiologic frontier is trespassed. In the eye the current of action in the retina is closely proportionate to the logarithm of the physical magnitude of the light. According to Bliss (6) the adsorption in the tissues should be proportionate to the logarithm of the dose, rather than to the dose itself. It must however be said that the coincidences, shown by Bliss of log dosis‐probit‐curves, departing somewhat from normality, and suitably selected fragments of Langmuir‐sigmoids, are little convincing evidence for his views, because of the large flexibility of the sigmoids (3 parameters). The keen interest taken by Bliss in departures from normality of dosage mortality data is comparable to the interest taken in departure from normality at large in the childhood of biostatistics. It was seldom forgotten then, to compute the skewness and the kurtosis, or better still, to fit the best‐suiting Pearsonian curve, of any distribution. Much more seldom however, anything was done with the results. Nowadays the value of departures from normality is considerably depreciated. Significant departures from any normal or Pearsonian curve may always be shown, by taking enough observations, because not a single natural distribution can be exactly identical with one of those curves.
Een noodzakelijke correctie van de overschrijdingsgrenzen voor steekproefgemiddelden bij toepassing van stratified sampling
Authors: de Leeuw Th. A. 
Published: April 2008

Summary  (A necessary correction of the control chart limits for averages of samples in the case of stratified sampling).Application of stratified sampling results in smaller fluctuations of sampling than where the same total number of individuals is drawn at random from the superposed strata.The proportion of the standard errors of the averages obtained by these two sampling methods may be expressed by a factor ϕ (o ≤ϕ≤ 1). The probability limits, between which the random sampling results would be fluctuating normally, should be corrected according to this factor.A few properties of ϕ are discussed. This is graphically illustrated. Remarks have been added about the relation between the shape of the population of the sampling averages and the population from which the individuals are drawn, and about the difficulties which arise when the populations are non‐Gaussian.
Een statistisch problaem in de Klimatologie
Authors: Levert C. 
Published: April 2008

Summary  (A statistical problem in Climatology).The Climatological Section of the Royal Meteorological Institute of the Netherlands was asked to solve the following problem: Is the decrease in the quantity of precipitation along the eastern border of the Noord‐Oost‐polder of the Zuider‐Zee since reclamation in 1942, significant?The data from the stations at Lemmer and Kampen have been statistically analysed. The results of this analysis may be interpreted as follows: if the change is a real one, it is overshadowed by the well known fluctuations of chance.In the course of the computation two questions arose: speaking generally

when altered circumstances produce a certain change in the true value of the phenomenon, how many measurements have to be made in order to prove this change to be significant? and
being able to make only a certain number of measurements, what is the minimum real change in the phenomenon which can be proved to be significant?The theory developed in this article and verified by numerical climatological data may well be generalised and may then be useful in other branches of applied science.
De omvang van de steekproef bij een enkelvoudig steekproefsysteem
Authors: Enters J. H. 
Published: April 2008

Summary  (Sample size for a single sampling scheme).The operating characteristic of a sampling scheme may be specified by the producers 1 in 20 risk point (p1), at which the probability of rejecting a batch is 0.05, and the consumers 1 in 20 risk point (p2) at which the probability of accepting a batch of that quality is also 0.05.A nomogram is given (fig. 2) to determine for single sampling schemes and for given values of p1and p2the necessary sample size (n) and the allowable number of defectives in the sample (c).The nomogram may reversedly be used to determine the producers and consumers 1 in 20 risk points for a given single sampling scheme.The curves in this nomogram were computed from a table of percentage points of the χ2 distribution. For v > 30 Wilson and Hilferty's approximation to the χ2 distribution was used.
Over correlatierekening en de herleiding van klimatologische reeksen
Authors: Varangot V. 
Published: April 2008

Summary  (A useful climatological application of regression theory) It is often required to estimate the 24th mean temperature from a few known temperatures, e.g. at 8h, 14h and 19h, when a sample of accurately known 24h means is available. The usual method is to add a constant to the mean of the three temperatures.It is better however to compute a regression equation of the accurate 24h means on the three temperatures.An example is given, showing that the efficiency of the regression method is about 6 times as great as that of the usual method.
Over de spreiding bij het droge‐stofonderzoek van brood
Authors: Burg L. v. d. 
Published: April 2008

SummaryThe accuracy of the determination of the amount of solids in bread.Of a loaf with a nominal weight of 800 grams only about 480 grams remains after complete drying. This so‐called ‘amount of solids in bread’ is regularly checked by samples. From a batch of loaves a group of at least 5. but usually more, are taken at random and weighed. From this group one is selected with a weight as nearly as possible equalling the average weight of the whole group; for two slices of this sample loaf the decrease in weight upon drying is determined in the laboratory, and is considered as representative for the entire batch.The accuracy of these determinations is analysed on the basis of 35 samples which were investigated in 3 different laboratories. The standard error is estimated at 5 grams per loaf. The influence of various factors, such as the method of sampling which may be altered in many ways, is briefly considered, while in a final section the results obtained are discussed from a practical point of view.
Het verbond tussen werkelijke verdeling, foutenverdeling en waarneem‐bare verdeling
Authors: Picard Drs H. C. 
Published: April 2008

SummaryThe relation between the true distribution, the error distribution and the observable distribution. If ξ is a chance variable with a ‘true’ distribution function ξ (ξ), and if ϕ (x—ξ; ξ) represents the distribution of the errors made in observing ξ, than the actual observations will be distributed according to the ‘observable’ distribution which arises from a superposition of the true and the error distributions. By making use of moment generating functions, relations are derived between the fundamental parameters—mean, variance, β1 and β2—of the three distributions mentioned above, under the supposition that these functions are all continuous and differentiable, and that the error distribution is symmetric. When these assumptions do not hold similar methods may still be employed. In the general case that the error distribution depends on ξ we arrive at equations (6) to (12), which, if this distribution is independent of ξ, simplify to equations (13) to (16); if the error distribution is normal these can be further reduced to (19) to (21), a set of equations already established by Sittig1)in a previous paper. The same method of computation can be extended to cases of more than one dimension, and equations (23) to (27) express the relations between the variances and the correlation coefficients for a two‐dimensional distribution.
De evolutie van net gebit van de orang oetan vergeleken met de evolutie van het gebit van de mens
Authors: Hooijer Dr D. A. 
Published: April 2008

SummaryThe evolution of the dentition of the orang‐utan compared with the evolution of the human dentition.From a comparison of the average robustnesses computed from a collection of 3170 prehistoric teeth with those observed in the teeth of 80 recent skulls it is concluded that the evolution of the dentition of Pongo pygmaeus follows behind the evolution of the human dentition along parallel lines. The data on which this conclusion has been based are set out in a Simpson diagram in fig 1 (with accompanying text in English).
Critiek op de “Hyperbolische Foutenwet”
Authors: Brethouwer D. H. G. , Hamaker H. C. 
Published: April 2008

SummaryCriticisms against the ‘Hyperbolic Error Distribution’. In a previous article in this journal (Vol. 1, p. 55, 1948) the hyperbolic error distribution was derived by theoretical argument, starting from simple hypotheses. Against this derivation criticisms have been raised from various sides. These are answered in the present paper.Though it is on the one hand acknowledged that an error has slipped into the previous arguments, it is on the other hand maintained that the hyperbolic distribution can be held upright on a slightly altered basis, namely on a set of approximate, instead of exact, equations.In a postscript the editors point out that serious objections can be raised against these altered views.
Frequentieverdelingen en mengproblemen
Authors: de Jong A. J. 
Published: April 2008

SummaryFrequency distributions and mixing problems.If in packages of a powdered mixture a minimum quantity of some essential and expensive component has to be guaranteed, the degree of homogeneity of the mixture becomes an important industrial probIem. The greater the dispersion, the greater will be the overweight required in order to satisfy the prescribed minimum conditions. The problems which may arise under such conditions and the value of a study of the mixing process and its efficiency are briefly discussed. In essence they amount to a study of frequency distributions describing the properties of the mixture.
Enige aspecten van de spreiding van arbeidsprestaties*
Authors: de Jong J. R. 
Published: April 2008

SummarySome aspects of the spread observed in time studies.In the introduction the importance of time studies in mass production is mentioned. Next figures 1, 2 and 3 give some examples of the frequency distributions observed for the time intervals required for cyclical factory operations. It is pointed out that for comparing different jobs the specific deviation, s/√t, is often more useful than the standard deviation, s, or the average time t̄. If greater detail is required a study of the historic sequency may be of advantage; this sometimes reveals marked periodicity in speed (fig. 5). If one cyclical operation is split up in a number of phases, the variance of the whole is often larger than the sum of the variances of th; components, wich demonstrates the existence of correlations. Sometimes the distribution of 1/t or of 1/t2 is found to be slcser to normal than that oft. In ajinal section the main causes of variation are briefly surveyed.
Het nut van waarshijnlijkheidspapier voor de variatiestatistiek*
Authors: Jr. G. van Iterson 
Published: April 2008

SummaryThe utility of probability paper in studying the statistics of biological variations.This paper mainly deals with various applications and theorems concerning arithmetic probability paper.It is pointed out that the so‐called ‘normal function’ introduced by Kapteyn and Van Uven [1,2] is the same function as that which would be obtained by plotting the corresponding distribution on arithmetic probability paper. For a normal distribution the ‘normal function’ is a straight line, for a logarithmiconormal distribution it is a logarithmic curve.Galton's well‐known apparatus for demonstrating the genesis of a normal distribution (fig. 5) was modijied by Kapteyn (fig. 6) so as to produce a skew distribution. The latter apparatus can be transformed into the former by a process of stretching and compressing in a horizontal direction, and this transformation is again described by the ‘normal function’ of the non‐normal distribution shown in fig. 6.If the dividing blocks in these apparatus are conceived infinitesimally small and all of equal height, the path of those grains of small shot which always fall towards the right, or always towards the left, is again the ‘normal function’, or its image with respect to a horizontal line.Further some applications of probability paper in correlation studies and for the representation of certain laws of growth are discussed.In ‘Appendix I’ a method for χ2‐testing the reliability of a normal distribution fitted by means of probability paper is described, white in ‘Appendix II’ a mathematical proof is given of a number of theorems that were merely enunciated in the main paper.
Rangcorrelatie en de schattingsproef van Varangot*
Authors: Hemelrijk J. 
Published: April 2008

SummaryRank correlation methods applied to an experiment on estimation of V. Varangot. The results of an experiment on estimation described by V. Varangot [i] are analysed with the method described in M. G. Kendal V S, Rank correlation methods “under the title, The problem of m rankings”. The main advantage of this method is the possibility of applying a significance test to the result.
De centrale gedachte van de correlatierekening1
Authors: Tinbergen J. 
Published: April 2008

SummaryThe basic idea of correlation analysisIn his introduction to the four following papers on applications of correlation methods, Prof. Tinbergen presents correlation analysis as the means of establishing relationships between the factors involved, in those fields of natural and social sciences, where proper experimenting is impossible.Prof. Tinbergen recommends that workers in different fields take cognizance of each other's results with applications of correlation analysis — hence this symposium. On the other hand, uncritical imitation of methods used succesfully in one field, e.g. biology, may lead to serious failure in another, e.g. economics.
Gebruik van correlatierekening voor het vaststellen van werktijden in het expeditiebedrijf
Authors: Sittig J. 
Published: April 2008

SummaryThe establishing of standards in the transport trade by correlation analysisA firm of wholesale grocers have to deliver, once a week, goods to their clients according to their varying specifications. Delivery is effectuated by the firm's motor trucks.Observations of standing and moving times were made by means of automatically recording instruments.Standard time of delivery is given by the equation:T = 2,29G + 10,64K + 1,82A + 19,11T… standard time in minutesG… total weight to deliver, in 100 kgK… number of clients to visitA… total distance to be covered, in km)