bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of the interactions of predatoryTyphlodromusmites with the European red mite,Panonychus ulmi(Koch)
Authors: Johnson D. L. , Wellington W. G. 
Published: October 2006

SummaryInteractions ofTyphlodromusmites and their prey, the European red mite, in orchard settings were examined through computer simulation. In particular, the consequences of very slow dispersal by the predators, compared with the weather‐dependent higher rates of prey dispersal, were elucidated. In simulations of the interactions of the predator and its prey, both dispersal and temperature strongly affected the available supply of juvenile prey, and thus could determine whether the predators on an individual tree survived or perished.
Dispersion analyses and resource utilization of aphid parasitoids in a non‐depletable environment
Authors: Trumble John T. , Oatman Earl R. 
Published: October 2006

SummaryDispersions and resource utilization of primary and secondary parasitoids developing in non‐depletable primary host populations were determined for an aphid‐parasitoid community occurring on strawberries. Analyses of dispersions based onGreen's coefficient andLloyd's Patchiness Index indicated parasitized aphids were highly aggregated initially, became less aggregated as density increased, and remained aggregated following collapse of the aphid populations. The “index of aggregation” values calculated usingTaylor's Power Law concurred with results from the other indices, and the similarity of the regression coefficients from both seasons suggests that the index of aggregation may be characteristic for communities as well as species. Analysis withIwao's regression of mean crowding on the mean generated similar results when population data were stratified temporally, and also indicated that the individual was the basic unit of the population.In a non‐depletable environment, oviposition of individuals exhibiting an aggregated dispersion pattern within clumps of hosts provides primary parasitoids with a suitable trade‐off between energy utilization or genetic potential, and losses associated with hyperparasitism.
Postmetamorphic growth, survival, and age at first reproduction of the salamander, hynobius nebulosus tokyoensis Tago in relation to a consideration on the optimal timing of first reproduction
Authors: Kusano Tamotsu 
Published: October 2006

SummaryThe postmetamorphic growth and survival of the salamander Hynobius nebulosus tokyoentisTago were surveyed in the study site located in Habu village of Hinodemachi, a suburb of Tokyo City, during 1975–1981. A laboratory experiment on the growth rate of juveniles was conducted in parallel with the field survey. The result indicated that this salamander grew at the rate of 8,mm in s.v.l. per year during the juvenile stage, but its growth rate decreased markedly as low as 1.8 mm for males and 1.1 mm for females, once it had attained sexual maturity. According to the “capture‐recapture” procedure the annual survival rate after metamorphosis was found to be quite high; that is, approximately 0.7. By using the growth rate of juveniles and the difference between the sizes at metamorphosis and sexual maturity, the age at first reproduction was estimated to be 4 year for males and 5 year for females.From the data obtained in this study, the intrinsic rates of increase (r) were calculated for various values of age at first reproduction under different survival schedules, and the relationship between the age at first reproduction and fitness as measured by r was examined. The result indicated that an optimal age maximizing fitness always existed under respective survival schedules, and the observed age at first reproduction of this salamandei was found to coincide well with the predicted optimal age.
Reproductive strategy of insects as adaptation to temporally varying environments
Authors: Tsuda Yoshio 
Published: October 2006

SummaryDiversity of oviposition curve observed in 125 insects was analysed using the ratio of the length of period for development to that for reproduction. On the basis of this empirical data, two extreme reproductive patterns were selected: prolonged reproduction with early maturity and concentrated reproduction with late maturity. Population growth of the species with each reproductive pattern was calculated usingLeslie Matrix under some simulated fluctuating environments where the length of time during which the environments change is short compared with the time required to stabilize age structure. These simulation studies show that there is an optimal ratio of the length of period for development to that for reproduction in achieving high population densities and this ratio varies depending on the favorableness of environment for reproductive success: as the environmental favorableness decreases, the optimal ratio becomes larger.
The regulation of activity in populations of the terrestrial slug Limax maximus (Gastropoda; Limacidae)
Authors: Rollo Christopher David 
Published: October 2006

SummaryThe activity of the slug Limax maximus was studied in relation to weather. Three hundred‐and‐fifty‐eight hourly observations of activity and weather were made on 21 nights from May until October, 1976. Factors causally important to molluscan activity were included in a step‐down correlation‐regression analysis of daily and seasonal behavior. The analysis was also performed using weather data from the previous hourly observation. Models using lag‐weather did not explain as much variability as did concurrent weather.The regression models explained about 73% to 87% of the observed variation in activity. The most important factors included in the regression models were time of day (circadian rhythm), light intensity, changes in light intensity and surface temperature. Shelter temperature, temperature gradients, length of the night, and time of sunset were also included in some models. Age and hydration were shown to be key factors in other experiments.A model incorporating weather thresholds estimated from field data explained 83.06% of the variability in the activity of L. maximus over the season. The values predicted from the model did not differ significantly from those actually observed in the field (Kolmogorov‐Smirnov test, p>0.50).
A population study of the japanese wood mouse, Apodemus speciosus (Mammalia: Muridae), with reference to its social behavior
Authors: Kondo Takaki 
Published: October 2006

SummaryThe role of social behavior on the population regulation of the Japanese wood mouse, Apodemus speciosus, was studied in the Ashu Experimental Forest of Kyoto University by monthly trapping and direct observation on the social behavior at the artificial feeding site. The census was carried out from May to October in 1974 and 1975, and the direct observation in June, August and October, 1975.In the study area, the Japanese wood mouse has two breeding seasons in a year: in spring and in autumn. Minimum survival rate was high in the non‐breeding season and low in the breeding season. It was negatively correlated to the number of sexually active adults in both sexes.Home ranges of females tended to be mutually exclusive, and female residents prevented the settlement of female immigrants. On the other hand, home ranges of males overlapped largely and males had a straight social hierarchy. Subordinate males tended to disappear more often than dominant males did, but male residents did not hinder the settlement of male immigrants. Males may regulate their number by driving out the subordinate males, while females by spacing behavior.
Different response in respiration between predaceous and phytophagous lady beetles (Coleoptera: Coccinellidae) to starvation
Authors: Tanaka Koichi , Itô Yosiaki 
Published: October 2006

SummarySurvival times and changes in the respiratory rates and the live body weights of a predaceous lady beetle, Coccinella septempunctata bruckiiMulsant, and a phytophagous lady beetle, Henosepilachna vigintioctopunctataFabricius, under starved conditions were compared.
Females of C. septempunctata survived for a long time, 91.4±27.2 days, under starved conditions. On the other hand, males of C. septempunctata and males and females of H. vigintioctopunctata survived for 31.3±10.2, 17.6±6.0 and 22.9±5.3 days, respectively. These values were much shorter than that of C. septempunctata females.
The respiratory rate of starved C. septempunctata increased on the first day of starvation, but hereafter rapidly decrased till the fourth day, keeping an almost constant level thereafter. On the tenth day of starvation, the respiratory rates of C. septempunctata were 56.4% in males and 58.5% in females of initial values. The respiratory rate of males was 1.47 to 2.14 times as high as that of females, and there were significant differences between the two.
Males and females of C. septempunctata lost their body weights by 20.2% and 17.8% of initial weights, respectively, during the first ten days of starvation.
The respiratory rate of starved H. vigintioctopunctata did not significantly change till the fourth day of starvation, and thereafter decreased slowly. On the tenth day of starvation, the respiratory rates of H. vigintioctopunctata were 70.3% in males and 74.8% in females of initial values. These values were much higher than those of C. septempunctata.
Males and females of H. vigintioctopunctata lost their body weights by 22.4% and 25.4% of initial weights, respectively, during the first ten days of starvation. Thus under starvation H. vigintioctopunctata underwent the larger weight loss than C. septempunctata.
Differences in strategies against starvation between poikilothermal predators and herbivores and their roles in population dynamics were discussed.
The species‐area relation for archipelago biotas: Islands as samples from a species pool
Authors: Kobayashi Shiro 
Published: October 2006

SummaryIf the immigration of species from a mainland or among islands is taken into account, each island of an archipelago can be regarded as a sample from a species pool. When two or more islands are combined so as to give larger samples, the resultant species‐area relation does not differ from that observed in a continuous and homogeneous habitat on a mainland. This relation can be described by either of the two mathematical models proposed before (Kobayashi, 1975, 1976). A power function seems to be insufficient because the discrepancy between the observed and the calculated values becomes larger with the increasing area. In a log‐log plot, the slope values for these alternatives to a power function vary continuously from 1 to 0 as the area increases. Owing to the spatially clumped distribution of each species, the number of species found on a single island is less than that found on several smaller islands of equivalent total area. Hence the species‐area relation for individual islands has a smaller slope value than that obtained by combining the different numbers of islands and approaches a power function in form. From these results, it is concluded that the species‐area data on archipelago biotas are equivalent to the case where separate samples of different sizes are drawn from a universe in which each species is spatially distributed in clumps. The properties of archipelago biotas which have so far been evidenced or predicted are consistent with this conclusion.
Studies on the distribution pattern of the pine needle gall midge, Thecodiplosis japonensisUchida etInouye (Diptera: Cecidomyiidae) in a pine forest
Authors: Soné Koichi , Takeda Hiroshi 
Published: October 2006

SummaryNumerical changes and distribution patterns of the pine needle gall midge, Thecodiplosis japonensisUchida etInouye, were studied during the period from 1978 to 1979 in a young plantation of Pinus thunbergii in Shiga Prefecture, Japan. The survivorship curve of this species was characterized by a low mortality of larvae in galls and two high mortalities before the formation of galls and during the overwintering period in soil.The within and between‐trees distributions of eggs and larvae in galls were examined by using the regression method. The egg distribution per shoot was aggregative both within and between host plants. The within‐tree variations in numbers of eggs per shoot were related to the differences in the abundance of available needles for oviposition per shoot among the canopy layers. The between‐tree variations reflected the heterogeneous emergence of adult females in the study plot. The degree of aggregation increased from egg to gall stage in both within‐ and between‐tree distributions and the increase was explained by the different mortality of larvae within trees and the inversely density‐dependent mortality between trees.The distribution patterns in the soil habitat stages were examined by the patchness index (). This species showed aggregative distributions in soil stages. There was a correlation in spatial patterns of adult emergence between the successive generations.The distribution properties of this species were discussed in connection with the population dynamics and the availability of host plants in the study plot.
Simulation of movement and egglaying in Danaus plexippus (Lepidoptera: Nymphalidae)
Authors: Zalucki Myron P. 
Published: October 2006

SummaryA model simulating the movement and oviposition of monarch butterflies over a female's life time is presented. The model's predictions compare favourably with observed data and suggest that females who lay eggs in an optimal fashion should have low directionalities in areas with high host plant density (patches and single plants) and high directionalities in areas with low host plant density. The model also provides one means of combining individual animal processes and spatial heterogeneity into population dynamics.
How three rocky shore snails coexist on a limited food resource
Authors: Spight Tom M. 
Published: October 2006

SummaryCompetition theory poses a major problem when several species coexist on what appears to be one resource. Three Thais species living on the Pacific Northwest Coast provide an example: at many sites, all three depend primarily on one barnacle species. Growth rates of three species were measured for 3 years and these provide an indirect means to assess how these snails use their common food resource. Major temporal differences were observed:T. lamellosa grew 0–1 mm/mo during the spring and 2–3 mm/mo during the summer, while T. emarginata and T. canaliculata grew 2–3 mm/mo during the spring and 0–1 mm/mo during the summer. However, all species are opportunists when food is available, and seasonal and interspecific differences disappeared when all three species were kept well fed together in the laboratory. Therefore, temporal differences arise from spatial segregation rather than from intrinsic differences in activity, and must arise because barnacle abundance patterns differe consistently from one area of the shore to another. Species‐specific activity patterns lead each species to a food intake that is independent of the food supply on the shore as a whole and is also independent of food intake by the other two species. Where two snail species depend upon a single food species, their use of the food supply appears to make it function as two different resources. This resource use is possible because prey quality is markedly dependent on shore level.
Comparative studies on the seasonal occurrence, nymphal development and food menu in two giant water bugs, Diplonychus japonicus vuillefroy and Diplonychus major esaki (Hemiptera: Belostomatidae)
Authors: Okada Hiroaki , Nakasuji Fusao 
Published: October 2006

SummaryWe compared the seasonal changes in population density and nymphal development at different water temperatures and under different food conditions between two giant water bugs, Diplonychus japonicus and D. major, in Okayama, Japan.D. japonicus produced 1–2 generations a year, while D. major was strictly inivoltine. The developmental velocity was higher in D. japonicus than in D. major. The thermal constant of D. japonicus was less than that of D. major. These results suggest that D. japonicus is adapted, to higher water temperature than D. major. In the field, D. japonicus preyed predominately on Lymnaeidae and Physidae snails, while D. major preyed on aquatic insects such as dragonfly nymphs.
Pollination of strawberry by the stingless bee, Trigona minangkabau, and the honey bee, Apis mellifera: An experimental study of fertilization efficiency
Authors: Kakutani Takehiko , Inoue Tamiji , Tezuka Toshiyuki , Maeta Yasuo 
Published: October 2006

SummaryTo know basic information about the stingless bee, Trigona minangkabau, and the European honey bee, Apis mellifera, as pollinator of strawberry, we set three greenhouse areas: the honey bee introduced area, the stingless bee introduced area and the control area. Foraging and pollination efficiencies of the two bee species were studied comparatively.During the experimental period (10 days), the stingless bee foraged well and the nest weight did not change, though the honey bee often foraged inefficiently and the nest weight decreased by 2 kg. The average nectar volume of a flower was lower in the honey bee area (0.02 μl) and nearly the same in the other two areas (0.1 μl).We make a numerical model to describe pollination and fertilization process. This model shows that one visit of the honey bee pollinated 11% of achenes and one visit of the stingless bee did 4.7% on average and that 11 visits of the honey bee or 30 visits of the stingless bee are required per flower to attain normal berry (fertilization rate, 87%). In this study, the rate of deformed berries in the stingless bee area (73%) was lower than that of the control area (90%), but higher than that of the honey bee area (51%). From our numerical model, we conclude the stingless bee could pollinate strawberry as well as the honey bee if we introduced 1.8 times of bees used in this experiment.
Factors associated with use of medications with potential to impair cognition or cholinesterase inhibitors among Alzheimer's disease patients
Authors: Huey Edward D. , Taylor Joy L. , Luu Pauline , Oehlert John , Tinklenberg Jared R. 
Published: October 2006

BackgroundThe aim of this study was to use a signal detection method to examine the prevalence of, and patient characteristics associated with, medication with potential to impair cognition and cholinesterase inhibitor use in patients with Alzheimer's disease.MethodsA cross‐sectional study was conducted of 1,954 patients with a diagnosis of probable or possible Alzheimer's disease. Concurrent medications were measured, specifically: (1) a medication with potential to impair cognition or (2) a cholinesterase inhibitor. Predictor variables included age, gender, ethnic group, education, age of symptom onset, number of prescriptions, number of medical diagnoses, Mini‐Mental State Examination (MMSE), Blessed‐Roth Dementia Rating Scale (BRDRS), probable versus possible AD diagnosis.ResultsFifteen percent of the Alzheimer's disease patients were on a medication with potential to impair cognition, and 44% were on a cholinesterase inhibitor. Patient characteristics associated with the prescription of a medication with potential to impair cognition included total number of prescription medications, low education, low MMSE, older age, reported lack of vitamin use, and more medical diagnoses. Patient characteristics associated with the prescription of a cholinesterase inhibitor included reported use of vitamins, the total number of prescription medications, fewer medical diagnoses, lower age of symptom onset, and higher education.ConclusionsDetermining the patient characteristics associated with the prescription of a medication with potential to impair cognition can help clinicians identify patients who are at risk for drug‐related morbidity. Patient characteristics unassociated with dementia appear to influence the prescription of cholinesterase inhibitors. Signal detection analysis is well suited to this type of research.
Joint ventures around the globe from 1990–2000: Forms, types, industries, countries and ownership patterns
Authors: Moskalev Sviatoslav A. , Swensen R. Bruce 
Published: October 2006

AbstractJoint ventures (JVs) and alliances are important forms of inter‐organizational cooperation because they allow firms to achieve complex mutual tasks, otherwise impossible using simple arm's‐length contracts, but without actually acquiring one another. In light of recent trends in globalization, this feature of JVs and alliances is vital to multi‐national corporations (MNCs). These firms have complex operations, making simple arm's‐length contracts insufficient. MNCs are also very large, so that mergers and acquisitions and takeovers are extremely expensive. In this paper, we describe global trends in JVs and alliances for the period 1990 to 2000, utilizing the Thomson Financial SDC Platinum database. We survey the relevant literature on JVs and alliances, and provide a detailed description of the world of JVs and alliances as depicted by this database. We report a number of interesting facts regarding the forms and types of JVs and alliances, their industry and geographic distribution, and patterns of ownership.
Sex differences in brain activation patterns during processing of positively and negatively valenced emotional words
Authors: HOFER ALEX , SIEDENTOPF CHRISTIAN M. , ISCHEBECK ANJA , RETTENBACHER MARIA A. , VERIUS MICHAEL , FELBER STEPHAN , WOLFGANG FLEISCHHACKER W. 
Published: October 2006

Background. Previous studies have suggested that men and women process emotional stimuli differently. In this study, we used event-related functional magnetic resonance imaging (fMRI) to investigate gender differences in regional cerebral activity during the perception of positive or negative emotions.Method. The experiment comprised two emotional conditions (positively/negatively valenced words) during which fMRI data were acquired.Results. Thirty-eight healthy volunteers (19 males, 19 females) were investigated. A direct comparison of brain activation between men and women revealed differential activation in the right putamen, the right superior temporal gyrus, and the left supramarginal gyrus during processing of positively valenced words versus non-words for women versus men. By contrast, during processing of negatively valenced words versus non-words, relatively greater activation was seen in the left perirhinal cortex and hippocampus for women versus men, and in the right supramarginal gyrus for men versus women.Conclusions. Our findings suggest gender-related neural responses to emotional stimuli and could contribute to the understanding of mechanisms underlying the gender disparity of neuropsychiatric diseases such as mood disorders.