bluuebunny/crossref_metadata_2025 huggingface dataset:
Microsculpture in UK ground beetles: Are there patterns?
Authors: DOBERSKI Julian , WALMESLEY George
Published: September 2010

Cuticular microsculpture “cells” were measured on 78 species of UK ground beetles. The data were analyzed to establish whether the type of microsculpture could be linked to ground beetle size (length) or ecological preferences. Larger species tended towards isodiametric patterns, while more of the smaller species showed a transverse or effaced pattern. There was no indication that preferences for dry or moist habitat were linked to microsculpture type, which had been suggested in the literature.
Host stage preference, functional response and mutual interference of Aphidius matricariae (Hym.: Braconidae: Aphidiinae) on Aphis fabae (Hom.: Aphididae)
Authors: TAHRIRI Sepideh , TALEBI Ali A. , FATHIPOUR Yaghoub , ZAMANI Abbas A.
Published: September 2010

Host stage preference, functional response and mutual interference of Aphidius matricariae (Haliday) (Hym.: Braconidae: Aphidiinae), parasitoid of the black bean aphid, Aphis fabae Scopoli (Hom.: Aphididae) were investigated in a growth chamber at a temperature of 25°C, 65% relative humidity and a photoperiod of 16 h light : 8 h dark on the PP8 variety of sugar beet. Nicholson's model and linear regression were used to determine per capita searching efficiency and interference coefficient, respectively. The highest parasitism percentage was observed on the third instar nymphs of A. fabae in both choice and no‐choice preference tests. There was significant difference between rates of parasitism on different stages of A. fabae (P < 0.01). Using logistic regression, a type II functional response was determined for A. matricariae. The Holling and Rogers models were used for estimating searching efficiency (a) and handling time (Th). The data was fitted by the Rogers equation better than by the Holling disc equation based on the R2 values. The estimated values of searching efficiency and handling time were 0.040 ± 0.013/h and 3.439 ± 0.383 h, respectively. The per capita searching efficiency decreased significantly from 0.272 to 0.139 as parasitoid densities increased from one to five. Therefore, different host‐parasitoid ratios could affect the efficacy of A. matricariae.
Diet composition of the endangered giant water bug Lethocerus deyrolli (Hemiptera: Belostomatidae) in the rice fields of Japan: Which is the most important prey item among frogs, fish, and aquatic insects?
Authors: HIRAI Toshiaki
Published: September 2010

The food habits of the endangered giant water bug, Lethocerus deyrolli, were studied in the rice fields of Nose, in the north of Osaka Prefecture, Japan. Field observations revealed that frogs were the most important prey item. Frogs represented 86.4% and 78.6% in the diet of L. deyrolli in spring and summer, respectively. Among seven species of three families (Hylidae, Rhacophoridae, and Ranidae) exploited by L. deyrolli, the most important food item was adult Hyla japonica in spring and juvenile Rana nigromaculta in summer. Fish and aquatic arthropods were not considered important foods for L. deyrolli. The frog‐dependent food habits indicate that the recovery and conservation of frogs should be prioritized to protect L. deyrolli from extinction.
The Evolution of Helicobacter pylori Antibiotics Resistance Over 10 Years in Beijing, China
Authors: Gao Wen , Cheng Hong , Hu Fulian , Li Jiang , Wang Lihui , Yang Guibin , Xu Le , Zheng Xiaoli
Published: September 2010

Objectives:  To evaluate Helicobacter pylori antibiotics resistance evolution from 2000 to 2009 to amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin and moxifloxacin in Beijing, China.

Methods:  A total of 374 H. pylori strains isolated from 374 subjects who had undergone upper gastrointestinal endoscopy from 2000 to 2009 were collected and examined by E‐test method for antibiotics susceptibility.

Results:  The average antibiotics resistance rates were 0.3% (amoxicillin), 37.2% (clarithromycin), 63.9% (metronidazole), 1.2% (tetracycline), 50.3% (levofloxacin) and 61.9% (moxifloxacin). Overall resistance to clarithromycin, metronidazole, and fluoroquinolone increased annually (from 14.8 to 65.4%, 38.9 to 78.8%, and 27.1 to 63.5%, in 2000 or 2006–2007 to 2009, respectively). The secondary resistance rates were much higher than primary rates to these antibiotics, which also increased annually in recent 10 years.

Conclusions:  The trend of clarithromycin, metronidazole, and fluoroquinolone resistance of H. pylori increased over time and the resistance to amoxicillin and tetracycline was infrequent and stable in Beijing. Clarithromycin, metronidazole, and fluoroquinolone should be used with caution for H. pylori eradication treatment.
Socio‐medical Problems of Epileptics A Preliminary Report
Authors: JUUL‐JENSEN PALLE
Published: September 2010

Excluding disability pensioners and married women, a series of 736 adult epileptics revealed only 23 patients with occupational difficulties solely due to epilepsy. It was found that both the psychological constitution and the severity and type of epilepsy are of importance in the social adjustment of the patients.

Si l'on tient hors de compte les gens en retraite et les femmes mariées, on constate qu'une série de 736 adultes épileptiques n'a donné que 23 malades dont le travail est difficile par suite d'épilepsie seulement. Il s'est révélé que la constitution psychologique, ainsi que la gravité et le type de l'épilepsie ont de l'importance dans l'adaptation sociale des malades.
Research on Epileptic Drugs
Authors: SOREL L.
Published: September 2010

Investigation of the electivity of highly active drugs in the treatment of epilepsy has brought three findings to the front: the diversity in the action of anti‐epileptic drugs is certain in clinical use; the same product can be anti‐epileptic as well as epileptogenic according to the physiological or physiopathological state of the person concerned in the test; the activity of only one sensibilisating epileptogenous factor is very different according to the form of epilepsy in question.

The experimental tests should be as numerous as possible, in order to examine the various aspects of the epileptic process.

The tests should be executed with very much precision and if possible under EEG control. Two tests evolved by the author have been used.

Correlations between human epilepsy and experimental tests appear to have been established in the case of certain tests.

Après avoir remarqué l'électivité de nombreuses substances très actives dans le traitement de l'épilepsie on peut dégager 3 constatations: la diversité d'action des antiépileptiques en clinique est certaine; une měme substance peut ětre anti‐épileptique ou épileptogène suivant l'état physiologique ou physiopathologique du sujet en cause; l'action d'un měme facteur sensibilisant épileptogène sera différent selon la forme d'épilepsie en jeu.

Les tests expérimentaux devront ětre les plus nombreux possibles afin d'interroger le processus épileptique sous ses divers aspects.

Les tests devront ětre le plus précis possibles et si possible sous contrǒle E.E.G. Deux tests personnels ont été utilisés.

Les corrélations entre l'épilepsie humaine et les tests expérimentaux semblent établies pour certains tests.
Vocational Training of Epileptics
Authors: JUUL‐JENSEN PALLE
Published: September 2010

In 52 patients, who during the period from 1945 to 1958 received financial support for vocational training from the Danish Disability Insurance Tribunal, this training was completed with success only in 16 (or 31%). The series seemed to be very suitable for rehabilitation, since all the patients had been closely examined and adjudged before any aid was granted. The results of the follow‐up study must therefore be said to be highly disappointing. Accordingly, strict criteria must be applied in the selection of epileptics who are to be admitted to the rehabilitation centres which will be established in this country (Denmark) in the near future.

La préparation professionnelle de 25 malades ayant reçu à ce propos une aide financière durant la période de 1945 à 1958 n'a été couronnée de succès complet que chez 16 d'entre eux. La série semblait très favorable à la réhabilitation: ils avaient été examinés et jugés conscientieusement avant que l'aide leur fǔt accordée. On peut dire par conséquent que les résultats d'une étude sérieuse ont fortement désappointé. Par suite, de rigoureux critères doivent ětre appliqués à la sélection d'épileptiques susceptibles d'admission aux centres de réhabilitation que l'on va établir en ce pays (Danemark) dans une proche avenir.
Basic Mechanisms of Single Cell Discharge in the Cerebral Cortex
Authors: LI CHOH‐LUH , CHOU SHELLEY N. , HOWARD SAXTON Y.
Published: September 2010

Les observations ci‐dessus permettent de comparer les mécanismes du potentiel de décharge de fibres musculaires individuelles et ceux de neurones corticaux individuels. L'auteur en conclut que la decharge de la cellule individuelle dans le cortex cérébral est déterminée par deux mécanismes:

Un mécanisme intrinsèque, comme celui manifesté par l'instabilité du potentiel de la membrane au repos ou par des potientels d'oscillation rythmique qui sont probablement en rapport avec l'état électro‐chimique ou métabolique du neurone. Une décharge épileptique du cortex cérébral provient probablement d'un changement dans l'état métabolique (13) ou d'un trouble du mécanisme intrinsèque de quelques‐uns des neurones corticaux. Le mécanisme intrinsèque peut aussi ětre troublé par d'autres facteurs différents tels qu'une lésion de la membrane cellulaire, un changement dans les composants chimiques de l'entourage, ou bien encore, par stimulation électrique directe. Toutefois, ces facteurs n'existent pas lors de fonction physiologique normale du cerveau.

Un mécanisme extrinséque comme celui observé en certaines cas lors de petits potentiels se réptéant à des intervalles irréguliers et, en d'autres as, lors d'hyperpolarisation du neurone postsynaptique, dépendant entièrement de l'activité des cellules présynaptiques.
Dendritic Mechanisms
Authors: EIDELBERG E. , FRENCH J. D.
Published: September 2010

L'auteur émet la supposition d'une relation directe entre les événements électriques manifestés cornme “réponses dendritiques” et les décharges convulsives. I1 suggére aussi l'opinion que l'induction d'une activité convulsive à des endroits éoignes d'un focus primaire peuvent exprimer un phénomène de “release” du type général d'hypersensibilité d'énervation.
Competitor complaints in anti‐trust enforcement: Of Microsoft and mergers
Authors: Boyden Gray C .
Published: September 2010

Competition laws are intended to protect consumers but they can be twisted to serve the interests of competitors. Complaints by competitors can be useful in anti‐trust cases but, in general, anti‐trust agencies should be ‘deeply sceptical’ of such complaints which may reflect attempts to seek protection from a more efficient competitor. Both US and EU officials have not been sufficiently sceptical of complaints against Microsoft by its competitors: consumers will pay the price for this error.
Risk of Injury Associated with Opioid Use in Older Adults
Authors: Buckeridge David , Huang Allen , Hanley James , Kelome Armel , Reidel Kristen , Verma Aman , Winslade Nancy , Tamblyn Robyn
Published: September 2010

OBJECTIVES:To estimate the dose‐related risk of injuries in older adults associated with the use of low‐, medium‐, and high‐potency opioids.

DESIGN:Historical population‐based cohort study: 2001 to 2003.

SETTING:Quebec, Canada's, universal healthcare system.

PARTICIPANTS:Four hundred three thousand three hundred thirty‐nine adults aged 65 and older.

MEASUREMENTS:Population‐based health databases were used to measure preexisting risk factors for injuries in 2001/02 and drug use and injuries during follow‐up (2003). Type and dose of opioids were measured as time‐dependent variables, as were other drugs that may increase the risk of injury from sedating side‐effects or hypotension. The risk of injury per one adult dose increase in opioid dose was estimated using multivariate Cox proportional hazards models.

RESULTS:During the follow‐up year, 50.7% of the study population were prescribed drugs with sedating side effects, 15.3% were prescribed an opioid, 20.7% were concurrently using more than one sedating medication, and 3.7% were treated for an injury, fractures (55.1%) being the most common. After adjusting for concurrent drug use and baseline risk factors, low‐ (hazard ratio (HR)=1.36, 95% confidence interval (CI)=1.33–1.39) and intermediate‐potency (HR=1.05, 95% CI=1.02–1.07) opioids were associated with the risk of injury. Use of codeine combinations was associated with the highest risk of injury, a 127% greater risk (HR=2.27, 95% CI=2.21–2.34) per one adult dose increase. (The mean World Health Organization standardized dose in the study population was 1.71 ± 0.85 adult doses.)

CONCLUSION:Opioids increase the risk of injury in older adults, particularly codeine combinations.
Frequency of Malnutrition in Older Adults: A Multinational Perspective Using the Mini Nutritional Assessment
Authors: Kaiser Matthias J. , Bauer Jürgen M. , Rämsch Christiane , Uter Wolfgang , Guigoz Yves , Cederholm Tommy , Thomas David R. , Anthony Patricia S. , Charlton Karen E. , Maggio Marcello , Tsai Alan C. , Vellas Bruno , Sieber Cornel C. ,   for the Mini Nutritional Assessment International Group
Published: September 2010

OBJECTIVES: To provide pooled data on the prevalence of malnutrition in elderly people as evaluated using the Mini Nutritional Assessment (MNA).

DESIGN: Retrospective pooled analysis of previously published datasets.

SETTING: Hospital, rehabilitation, nursing home, community.

PARTICIPANTS: Four thousand five hundred seven people (75.2% female) with a mean age of 82.3.

MEASUREMENTS: The prevalence of malnutrition in the combined database and in the four settings was examined.

RESULTS: Twenty‐four data sets with information on full MNA classification from researchers from 12 countries were submitted. In the combined database, the prevalence of malnutrition was 22.8%, with considerable differences between the settings (rehabilitation, 50.5%; hospital, 38.7%; nursing home, 13.8%; community, 5.8%). In the combined database, the “at risk” group had a prevalence of 46.2%. Consequently, approximately two‐thirds of study participants were at nutritional risk or malnourished.

CONCLUSION: The MNA has gained worldwide acceptance and shows a high prevalence of malnutrition in different settings, except for the community. Because of its specific geriatric focus, the MNA should be recommended as the basis for nutritional evaluation in older people.
Visceral Fat Accumulation and Metabolic Risk Factor Clustering in Older Adults
Authors: Nomura Kazushi , Eto Masato , Kojima Taro , Ogawa Sumito , Iijima Katsuya , Nakamura Tetsuro , Araki Atsushi , Akishita Masahiro , Ouchi Yasuyoshi
Published: September 2010

OBJECTIVES: To examine the relationship between visceral fat area (VFA) evaluated using computed tomography (CT) scans and the number of metabolic risk factors in older adults.

DESIGN: Cross‐sectional study

SETTING: A community clinic in Tokyo, Japan.

PARTICIPANTS: Two hundred eighteen individuals aged 65 and older without impairments in activities of daily living who underwent geriatric health examination (63 men, mean age 74.5 ± 7.1; 155 women, mean age 75.3 ± 6.7).

MEASUREMENTS: VFA was obtained from a cross‐sectional image at umbilical level in the supine position using CT scanning. Metabolic syndrome components except waist circumference were measured using the criteria of the International Diabetes Federation.

RESULTS: There was a positive correlation between VFA and number of metabolic risk factors in men and women. Multiple regression analysis demonstrated that only VFA was significantly correlated with number of risk factors in men, whereas age and VFA were significantly correlated in women; body mass index was not correlated with number of metabolic risk factors in men or women. Dyslipidemia and high blood glucose were associated with higher VFA, but high blood pressure was not. There was a negative correlation between VFA and serum adiponectin level and a positive correlation between VFA and homeostasis model assessment of insulin resistance.

CONCLUSION: Visceral fat accumulation is associated with metabolic risk factor clustering even in the elderly population. These results have clinical implications for the management of obesity in older adults.
Hand‐Grip Strength Cut Points to Screen Older Persons at Risk for Mobility Limitation
Authors: Sallinen Janne , Stenholm Sari , Rantanen Taina , Heliövaara Markku , Sainio Päivi , Koskinen Seppo
Published: September 2010

OBJECTIVES: To determine optimal hand‐grip strength cut points for likelihood of mobility limitation in older people and to study whether these cut points differ according to body mass index (BMI).

DESIGN: Cross‐sectional analysis of data.

SETTING: Data collected in the Finnish population‐based Health 2000 Survey.

PARTICIPANTS: One thousand eighty‐four men and 1,562 women aged 55 and older with complete data on anthropometry, hand‐grip strength and self‐reported mobility.

MEASUREMENTS: Mobility limitation was defined as difficulty walking 0.5 km or climbing stairs. Receiver operating characteristic analysis was used to estimate hand‐grip strength cut points for likelihood of mobility limitation.

RESULTS: The overall hand‐grip strength cut points for likelihood of mobility limitation were 37 kg (sensitivity 62%; specificity 76%) for men and 21 kg (sensitivity 67%; specificity 73%) for women. The effect of the interaction between hand‐grip strength and BMI on mobility limitation was significant in men (P=.02), but no such interaction was observed in women (P=.16). In men, the most‐optimal cutoff points were 33 kg (sensitivity 73%; specificity 79%) for normal‐weight men, 39 kg (sensitivity 67%; specificity 71%) for overweight men, and 40 kg (sensitivity 57%; specificity 68%) for obese men. In women, BMI‐specific hand‐grip strength cutoff values was not markedly more accurate than the overall cutoff value.

CONCLUSION: The hand‐grip strength test is a useful tool to identify persons at risk of mobility limitation. In men, hand‐grip strength cut points for mobility increased with BMI, whereas in women, only one hand‐grip strength threshold was identified.
Mild Cognitive Impairment: Incidence and Risk Factors: Results of the Leipzig Longitudinal Study of the Aged
Authors: Luck Tobias , Luppa Melanie , Briel Susanne , Matschinger Herbert , König Hans‐Helmut , Bleich Stefan , Villringer Arno , Angermeyer Matthias C. , Riedel‐Heller Steffi G.
Published: September 2010

OBECTIVES:To provide information on age‐ and sex‐specific incidence rates of mild cognitive impairment (MCI) and risk factors for incident MCI.

DESIGN:Prospective longitudinal cohort.

SETTING:Leipzig Longitudinal Study of the Aged, a population‐based German study of the epidemiology of dementia and mild cognitive impairment.

PARTICIPANTS:At baseline, 1,692 subjects aged 75 and older were included in the sample.

MEASUREMENTS:Trained psychologists and physicians conducted structured clinical interviews including neuropsychological assessment and questions about sociodemographics, familial history of dementia, activities of daily living, subjective memory impairment, and lifestyle (alcohol consumption, smoking) at participants' homes. Structured third‐party interviews were conducted with proxies. Incidence was calculated according to the person‐years‐at‐risk method. Cox proportional hazards models were used to examine the association between risk factors and incident MCI.

RESULTS:During an 8‐year follow‐up period, 26.4% (n=137) of the 519 study participants (population at risk) were identified as incident MCI cases (person‐years=1,791.1). The overall incidence rate of MCI was 76.5 (95% confidence interval=64.7–90.4) per 1,000 person‐years. Older age, subjective memory impairment, impairment in instrumental activities of daily living, and antecedent lower cognitive performance were found to be significantly associated with the development of future MCI.

CONCLUSION:MCI is highly incident in the elderly population. For the purpose of early detection of dementia, subjective memory impairment should be taken seriously as a possible prestage of MCI.
Systematic Review: Helping the Young to Understand the Old. Teaching Interventions in Geriatrics to Improve the Knowledge, Skills, and Attitudes of Undergraduate Medical Students
Authors: Tullo Ellen StC. , Spencer John , Allan Louise
Published: September 2010

It is unclear whether geriatrics‐specific educational interventions lead to improvement in students' knowledge, skills, and attitudes and whether successful interventions possess any consistent features. This review examines the effect of educational interventions on undergraduate knowledge, skills, and attitudes in geriatric medicine and concludes that a wide range of innovative designs have the potential to improve each of these parameters, although evidence of interventions that improve student skills is lacking, and further research is necessary to confirm the efficacy of specific teaching strategies in geriatrics.
Hormones, Seizures, and Lamotrigine: Oh, My!
Authors: Pennell Page B.
Published: September 2010

Oral Contraceptives Induce Lamotrigine Metabolism: Evidence from a Double-Blind, Placebo-Controlled Trial. Christensen J, Petrenaite V, Atterman J, Sidenius P, Öhman I, Tomson T, Sabers A. Epilepsia 2007;48(3):484–489.

Purpose

This study evaluates the effect of oral contraceptives on lamotrigine (LTG) plasma concentrations and urine excretion of LTG metabolites in a double-blind, placebo-controlled, crossover study in patients with epilepsy.

Methods

Women with epilepsy, treated with LTG in monotherapy and taking combination-type oral contraceptives, were randomized to treatment with placebo or a standard combination-type contraceptive pill. The dose-corrected trough plasma concentration of LTG and the ratio of N-2-glucuronide/unchanged LTG on urine after 21 days of concomitant placebo treatment was analyzed versus those after 21 days of concomitant treatment with the oral contraceptive pill.

Results

The mean dose-corrected LTG concentration after placebo treatment was 84% [95% confidence interval (CI), 45–134%] higher than after oral contraceptives, signifying an almost doubling of the concentration after cessation of oral contraceptives. Most of this increase took place within the first week after oral contraceptives were stopped. The N-2-glucuronide/LTG ratio in the urine was decreased by 31% (95% CI, −20–61%) when shifting from oral contraceptives to placebo.

Conclusions

Cessation of oral contraceptives leads to an 84% increase in the concentration of LTG. In parallel, the excretion of the N-2-glucuronide was decreased, indicating that the changes are caused by altered LTG glucuronidation. The change in LTG concentrations was observed within 1 week of the shift of treatment, suggesting that induction and deinduction of LTG glucuronidation is faster than that seen for other metabolic pathways (e.g., cytochrome P450).
On the Implications of a Stationary Urban Population For the Size Distribution of Cities
Authors: Haran E. G. P. , Vining Daniel R.
Published: September 2010

The paper analyzes the limiting case for a modified Yule‐Simon model of city growth. The aim of the paper is primarily to reintroduce geographers to the notion of a closed system of cities, i.e., a system of cities where the aggregate population is stationary in size. The Yule‐Simon model, while successful in dealing with the observed properties of open systems, is seen to break down for closed systems. Moreover, incorporating Simon's assumptions regarding intercity migration into the model produces implausible results.

Also, the traditional approach of employing entropy‐maximizing procedures assumes a certain pattern of intercity migration. This pattern, while not inherently implausible, does present features which are questionable. The authors conclude that an adequate theory for closed systems has yet to be developed.
Optimal Facility Location in a One‐Dimensional Spatial Market
Authors: Davies Omar
Published: September 2010

This paper analyzes properties of the optimal spatial arrangement of what may be interpreted as a class of public facilities. Optimality is defined as cost minimization. Three different optimality criteria are considered, and for each, the necessary and, sufficient conditions, market area size, and production levels, are derived. The relationship between optimal production levels and number of facilities needed is also considered. Next the results of implementing various pricing strategies are analyzed with emphasis given to marginal and uniform pricing. It is shown that, given certain conditions, all facilities incur operating deficits, given marginal pricing. Estimates on the level of the deficits are derived in terms of location rents. Finally, in the appendix, several important results from other studies are derived as special cases of the basic model.
Spatial Entropy
Authors: Batty Michael
Published: September 2010

A major problem in information theory concerns the derivation of a continuous measure of entropy from the discrete measure. Many analysts have shown that Shannon's treatment of this problem is incomplete, but few have gone on to rework his analysis. In this paper, it is suggested that a new measure of discrete entropy which incorporates interval size explicitly is required; such a measure is fundamental to geography and this statistic has been called spatial entropy. The use of the measure is first illustrated by application to one‐and two‐dimensional aggregation problems, and then the implications of this statistic for Wilson's entropy‐maximizing method are traced. Theil's aggregation statistic is reinterpreted in spatial terms, and finally, some heuristics are suggested for the design of real and idealized spatial systems in which entropy is at a maximum.
The Chromatic Traveling‐Salesmen Problem and Its Application to Planning and Structuring Geographic Space
Authors: Harvey Milton E. , Hocking Ralph T. , Brown J. Randall
Published: September 2010

The classical traveling‐salesman problem involves the establishment of a tour around a set of points in a plane such that each point is intersected only once and the circuit is of minimal total length. When the length of a salesman's tour cannot exceed a specified constant, the problem becomes that of finding the fewest number of salesmen such that every city is visited by a salesman and the length of each salesman's tour does not exceed a specified constant. This is the chromatic traveling‐salesmen problem. An algorithm for this problem is developed and is used to create periodic markets in parts of Sierra Leone. Fifteen rural areas were examined from Sierra Leone, and weekly market places were identified in each area. Salesmen were to be assigned to an area so that each market place was visited and each tour (or periodic ring) did not exceed forty hours. The chromatic traveling‐salesmen algorithm was used to minimize the number of periodic rings needed for each area and provide the specific tour for each ring.
A Three‐State Markov Model of Choice Behavior within Spatial Structures
Authors: Burnett Pat
Published: September 2010

This paper derives a simple mathematical model of spatial learning and choice by integrating several psychological theories, whose features accord with the results of empirical investigation in a previous paper [2]. A sample of homogeneous decision‐makers are assumed to make a succession of selections from a given set of initially unknown spatial alternatives (for example, a set of shopping places for a good). The decision‐makers pass through two states of “recognition” and “discrimination” learning, before reaching an equilibrium state. In the equilibrium state, decision‐makers have sufficiently learned the attributes of the alternatives so that satisfactory choices are always made. These assumptions permit the derivation of mathematical expressions to answer two questions: first, what proportion of decision‐makers will be in the equilibrium state after any given time interval, and second, what proportion of decision‐makers will choose any designated spatial alternative after the same time interval. In the second case, the proportion of decision‐makers choosing an alternative is predicted from the individuals' perceptions of the attributes of the alternatives. The paper concludes with an evaluation of the model and suggestions for its testing and further development.
Cognitive Maps and Spatial Behavior Of Consumers
Authors: MacKay David B. , Olshavsky Richard W. , Sentell Gerald
Published: September 2010

Two multidimensional scaling algorithms are used to externally measure cognitive maps of supermarket locations for a sample of sixty‐one supermarket shoppers. Issues raised in the construction of the cognitive maps are discussed. The relationship between the derived cognitive maps and consumer behavior is compared to the relationship between physical maps and consumer behavior. Behavior is shown to be more closely related to cognitive maps. Differences in cognitive maps are defined and canonically correlated with consumers' socioeconomic and locational attributes. While aggregate cognitive maps are closely associated with physical maps, there is substantial variation between individual maps. This variation is related to shopping behavior and selected socioeconomic and locational characteristics of consumers.
Dimensional Analysis: Some Applications In Human Geography
Authors: Haynes Robin M.
Published: September 2010

Dimensional analysis is introduced, and applications of it to human geography are considered. Primary and secondary dimensions are selected; techniques of dimensional analysis are used to derive and check a functional relationship drawn from central place theory, to test the dimensional implications of a power function (the Pareto gravity model), to disaggregate a theoretical parameter (the exponential distance decay coefficient), and to simplify a complex system of variables in agricultural location theory to a system of dimensionless products. Difficulties inherent in the application of dimensional analysis to human geography are discussed.
Variable Residential Density: Optimum Traffic Density and City Size
Authors: Fisch Oscar
Published: September 2010

In this paper we derive the optimal allocation of land between transportation and housing uses in an outer ring of a circular city, where the net population density is a constant, an exponent‐decaying, or a power‐decreasing function. We are also able to show that, under these circumstances, at no point in the optimal solution is all the land allocated to transportation use, proof that is, unlike previous work, independent of the solution of the same problem in the inner ring (Central Business District).
Profile Analysis by Analytical Techniques: A New Approach
Authors: Demirmen F.
Published: September 2010

A new analytical approach aimed at description of two‐dimensional surface profiles by the use of simple analytical definitions and simple descriptive measures is presented. The basic categories of profiles defined are: reversed, convex, concave, uniform, and composite, with subcategories including first‐order reversed, high‐order reversed, curviconvex, recti‐convex, curvi‐concave, recti‐concave, and regular. Extrema of such profiles, if they exist, can also be defined analytically. The descriptive measures proposed to describe a profile are: height, relief, length, slope, and curvature Both slope and curvature are indices of shape, and their properties for certain types of profiles can be mathematically predicted. Use of the analytical definitions and descriptive measures allows study of surface profiles, real or conceptual, by numerical and computer methods. The data required consist of a set of values at points of known locations on the profile.
Population Suburbanization in American Metropolitan Areas, 1940–1970
Authors: Guest Avery M.
Published: September 2010

Using census tract data, this paper shows that massive changes have occurred in density patterns of American metropolitan areas since 1950. Suburbanization of population has involved both large‐scale decongestion of central parts of metropolitan areas and also large‐scale outward deconcentration. Many metropolitan areas no longer have clearly distinguishable density patterns in their central and peripheral parts. At the present time, patterns of population distribution across metropolitan areas are becoming increasingly similar. Furthermore, current suburbanization patterns by census tract do not relate strongly to suburbanization patterns as measured by growth rates of crude central city and suburban rings in metropolitan areas. Finally, the paper shows that “density craters” in the center of many metropolitan areas may become more pronounced, although they may not extend outward.
Macrogeographic Functions: A Review And Extension
Authors: McCalden Gerald
Published: September 2010

The familiar potential of population can be generalized to yield a class of functions over the real plane, which may collectively be termed “macrogeographic functions.” On this basis, the properties of alternative choices of the component functions can be explored, and a more rigorous formulation of existing potential measures is rendered possible.
Entropy in Spatial Aggregation
Authors: Batty Michael
Published: September 2010

This paper introduces an approach to the measurement of locational phenomena in a spatial hierarchy using entropy statistics. A number of such statistics suitable for the study of spatial aggregation are derived, and each of these statistics is decomposed at different levels of the spatial hierarchy using principles of decomposition first applied by Theil. These decomposition statistics are compared with the variance analysis applied by Moellering and Tobler and with the spatial entropy measure suggested by Curry. The use of these statistics is then illustrated by data from the Reading subregion and New York City, and the paper is concluded with an analysis of a possible role for entropy and information in problems involving equal‐area zoning.
Fluctuation in the Random Spatial Economy and The Control of Inflation
Authors: Curry Leslie
Published: September 2010

A self‐contained spatial economy is set out as the steady‐state of a harmonic oscillator under Gaussian excitation. A dollar bill performs a random walk on a line with elastic barriers at each end and represents payments for traded goods. Diffusive surges of money and the fluctuations in zonal incomes are examined. The center, being less dependent on extra‐zonal trade, has fewer brakes on price levels and can more easily begin “inflation.” Imposing a uniform deflationary policy would cause the periphery to be squeezed without reason while the center would be affected too little and too late. The organization of a futures market in construction is analyzed as a spatially discriminating form of control.
The Effect of Spatial Stimuli on the Estimation of Cognitive Maps
Authors: MacKay David B.
Published: September 2010

Hand‐drawn and multidimensionally scaled maps of cities in the United States are compared with respect to their congruence with physical maps of the corresponding cities and with respect to subject's evaluations of their similarity to physical maps. The cities chosen are systematically varied to determine the effect of different spatial patterns on the subjects' performance. Hand‐drawn maps are shown to be more like physical maps. Subjects also rate their drawn maps as being more like actual maps than multidimensionally scaled maps. Changes with respect to the spatial pattern of stimuli are apparent.
Some Extensions to Rushton's Spatial Preference Scaling Model
Authors: Girt John L.
Published: September 2010

Rushton's spatial preference scaling model is extended and its computing algorithm modified in order to utilize more fully all the information contained in the input data set, and to make it a better predictor of choice behavior. The preference scale that is produced by the model measures the certainty with which generalizations can be made about choices between classes of objects. The model offers two significant advantages over commonly used spatial interaction models: freedom from a priori selection of the function relating choice to attributes of objects, and applicability to studies where the number of origin and destination zones is large relative to the populations involved.
Complexity and Redundancy in Binary Maps
Authors: Gatrell Anthony C.
Published: September 2010

The complexity of binary maps that is provided by the areal arrangement of colors is considered, and measured using information theory. In addition, information theory provides other measures that have an interpretation in a map context. One of these, redundancy, is examined and found to bear a striking empirical relationship to a spatial autocorrelation statistic. It is argued that spatial autocorrelation is, conceptually as well as empirically, the two‐dimensional equivalent of redundancy. It too measures the extent to which the occurrence of an event (color) in an areal unit constrains, or makes more probable, the occurrence of an event in a neighboring areal unit.
Planning Pedestrian Flows around a Subway Station: A French Case Study of the Time‐Distance Decay Functions
Authors: Marchand Bernard
Published: September 2010

Pedestrian flows to and from a rapid transit line station follow distance‐decay functions; an exponential model with a second‐degree exponent fits well the data. Observed flows in function of the distance are indicated. The average walking distance is larger than usually assumed: eleven minutes, i.e., one kilometer. The use of the subway by each professional category follows a definite pattern.
Model Specification in Stationary Random Fields
Authors: Haining Robert
Published: September 2010

The problems of model specification in one‐ and two‐dimensional stationary random fields are considered, with particular reference to the class of spatial autoregressions. The role of the autocorrelation function is discussed and it is shown to have a valuable exploratory use, especially in identifying directional bias in random fields. It is recommended that this analysis be supplemented by a likelihood‐ratio test, which permits more precise tests of hypotheses about the form of the underlying model.
The Location‐Production‐Allocation Problem With Nonlinear Production Costs
Authors: Osleeb Jeffrey P. , Cromley Robert G.
Published: September 2010

This paper develops a location‐production‐allocation model for the multiplant producer selling under the conditions of nonlinear production costs and a uniform pricing system. The primary goals of this paper are to incorporate the following criteria into a model: (1) production factors and location factors should be synthesized into a location‐production‐allocation problem; (2) the production function is nonlinear, implying economies and diseconomies of scale; (3) a systems approach should be utilized to solve for a global optimum. Within the context of these criteria, equilibrium conditions are derived for a location‐production‐allocation model. Finally, a heuristic technique to solve this problem is derived from the equilibrium conditions.
An Equivalence Theorem to Integrate Entropy‐Maximizing Submodels within Overall Mathematical‐Programming Frameworks
Authors: Coelho J. D. , Wilson A. G.
Published: September 2010

This paper presents a lemma and a theorem which demonstrate equivalent ways of formulating certain mathematical‐programming problems. The first shows, in general terms, how constraints can be “absorbed” into the objective function and vice versa. The second shows how such ideas can be applied to spatial analysis problems involving the minimization of development costs subject to interactions being determined by (suboptimal) entropy‐maximizing models. This provides both a new perspective on the relationship between programming and entropy models, and formulations that are computationally convenient.
Land Use Theory and Factor Intensities
Authors: Bannister Geoffrey
Published: September 2010

Although Thünen's rent theory has been formalized and extended, his interdependent spatial theory of factor intensities has received little attention. The solution must be developed from a fully specified rent equation that recognizes the dependence of outputs on inputs, and the important distinction between fixed and variable costs. A general solution is found for the one‐market, one‐productive‐factor case, with the limiting restriction that marginal revenue productivity must be rising more slowly than marginal costs. The flexibility and power of Thünen's model is shown by developing, from the general solution, scenarios under various market and production conditions.
Contact Number Properties in the Study Of Cellular Networks
Authors: Boots B. N.
Published: September 2010

The purpose of the paper is to determine if different generating processes produce cellular networks with distinctive contact number properties. Properties resulting from patterns produced by three generating processes, the Poisson, the compound negative binomial, and the “Smalley,” are examined in detail. The implications of the findings for the analysis of empirical cellular networks are discussed.
Comparison of Plane Forms
Authors: Tobler W. R.
Published: September 2010

Nonlinear two‐dimensional grid transformations are used to compare plane figures. The method is based on the identification of homologous points, and thus can be considered as a bidimensional extension of ordinary curvilinear regression, but is here approached from the point of view of cartography. All of the techniques illustrated by Thompson in 1917 can be mimicked by the computer program. Extensions of the method, based on the derivatives of the transformations, permit the determination of the axes of principal change, and also suggest numerical measures for the degree of similarity of topologically equivalent figures. Applications are illustrated in biology and geography, and more general uses are suggested.
Spatial Choice in Location‐Allocation Problems: The Role of Endogenous Attraction
Authors: Goodchild Michael F.
Published: September 2010

Spatial choice, a voluntary form of allocation of consumers to central services, is usually conceived as affected by two factors, distance and attraction. Although usually regarded as exogenous, attraction is in turn affected by the level of use a service receives, and thus by spatial choice. This paper explores the system defined by these relationships, largely by simulation. Proposals are made concerning the initiation and perturbation of the system, and attempts are made to generalize the results. Although it is difficult to connect form with process in such a system, it is possible to identify the factors responsible for system stability.
Allometric Analysis and Stream Channel Morphometry
Authors: Park Chris C.
Published: September 2010

The concept of allometric change, developed and widely applied in biology, is outlined, and the nature of static allometric changes in stream channel size, relative to drainage area, is considered at a variety of scales. Field observations from Devon, England, allow analysis of the allometric variations along individual channels, between tributaries within a network, and between streams within a region. Data collected from the literature allow these to be viewed in a global perspective. The analysis confirms the applicability and value of the concept of allometric change to channel form studies and suggests a tendency for streams to reach a steady‐state allometric situation when channel capacity increases at the same rate as drainage area. The importance of a range of factors in affecting the nature of the allometric relationships is also assessed.
An Approach toward Energy Balance Simulation over Rugged Terrain
Authors: Dozier Jeff , Outcalt Sam I.
Published: September 2010

We develop a digital computer model, based upon equilibrium temperature theory, of the magnitudes of the components of the energy balance for a mountainous topographic surface. The model includes an algorithm for calculating slope, exposure, and horizon information for every point on a digitized grid. Incoming solar and thermal radiation are then simulated for every point. At present the model is designed for clear‐sky conditions, but it could be modified for cloudy skies. Air temperature and humidity variations are specified by externally defined relations, and values for albedo and soil thermal properties are specified for every point on the grid. Wind speed variation over the grid is not modeled, but is specified by an empirical function. The model simulates net radiation, soil heat flow, sensible and latent heat flow, and surface temperature at specified time intervals. Output is in the form of contour maps.
Residential Mobility Patterns and Population Redistribution within the City
Authors: Huff James O.
Published: September 2010

A residential change model is derived that allocates migrants to housing vacancies using a Luce‐type choice process. The residential change model is then used as the basis for a small area forecasting model designed to predict changes in the size and composition of the population residing in designated areas of the city.
Urban Hierarchy and the Rank‐Size Distribution
Authors: Beguin Hubert
Published: September 2010

The paper analyzes some connections between the rank‐size distribution of cities and central place population models. Compatibility conditions with the rank‐size distribution are determined for the models considered. The values for two specific parameters under these conditions are determined, and additional interpretations of the rank‐size distribution are suggested.
Welfare Theory, Public Goods, and Public Facility Location
Authors: Lea Anthony C.
Published: September 2010

The paper discusses a number of issues that are important to the development of a useful normative “welfare theory” of the public space economy. Attention is specifically focused on theoretical welfare economic models of public goods provided at facilities to which consumers must travel for consumption. The recent analysis of Bigman and ReVelle [2] is subjected to critical scrutiny and found wanting. An alternative, more complex but still very simple, analysis is provided.
A Procedure to Generate Thiessen Polygons
Authors: Brassel Kurt E. , Reif Douglas
Published: September 2010

An algorithm to generate Thiessen diagrams for a set of n points defined in the plane is presented. First, existing proximal polygon computation procedures are reviewed and terms are defined. The algorithm developed here uses a rectangular window within which the Thiessen diagram is defined. The computation of Thiessen polygons uses an iterative walking process whereby the processing starts at the lower left corner of the diagram and proceeds toward the right top corner. The use of a sorted point sequence and dynamical core allocation provide for efficient processing. The presentation is concluded by the discussion of an implementation of the algorithm in aFORTRANprogram.
An Axiomatic Approach to Geographical Space
Authors: Beguin Hubert , Thisse Jacques‐François
Published: September 2010

Geographical space is a major concept in spatial analysis. Curiously enough, no attempt has so far been made to provide a general and rigorous presentation. In this paper, a formal definition of the basic geographical components is given. For that purpose, topology and measure theory are used. A general definition of geographical space is then proposed and some properties are examined. Finally, the relations between the proposed definition and the particular representations used in spatial analysis are discussed.