bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of interactive videodisc instruction using simultaneous‐time analysis on kinematics graphing skills of high school physics students
Authors: Brungardt John B. , Zollman Dean
Published: October 2006

Real‐time kinematical analysis of physical phenomenon is the graphing of displacement, velocity, and acceleration versus time data simultaneously with the motion of the object. Brasell (1987) found that students using real‐time analysis with microcomputer‐based laboratory tools significantly improved their kinematics graphing skills as compared to students using delayed‐time graphing (kinematics graphs produced after the motion of the object). However, using computer reanimation of videotaped images, Beichner (1990) found no difference in student learning between the simultaneous‐time (kinematics graphs produced simultaneously with the motion of the image of the object, such as a video‐recorded image or a computer reanimated image) and the delayed‐time treatments. This investigation considers student analysis of videodisc‐recorded images, with treatments over an extended time. Using quantitative, qualitative, and retention data, we found no significant learning difference between using simultaneous‐time and delayed‐time analysis for student understanding of kinematics graphs. However, the results imply that simultaneous‐time analysis may have advantages in some areas.
Genetic control of Hylemya antiqua III. Differences in pupation ability between two strains
Authors: Zurlini Giovanni , Robinson Alan S.
Published: October 2006

Some relevant traits of a wild (L) and a laboratory (C) strain of Hylemya antiqua (Meigen), determining differences in their pupation ability under experimental conditions have been investigated in relation to genetic control. The wild strain showed an intrinsic higher pupation ability than the laboratory strain. The minimum feeding period was 0.6 days longer for the C strain. The minimum larval dry weight was different for the two strains. With a normal feeding period C larvae pupated on average 1.63 days later than L larvae. By the shortening of the larval feeding period an acceleration of the larval development of both strains was observed: the acceleration of development was more marked for the wild strain. This result has been contrasted with published works on Drosphila. The consequences of these differences as far as the competitive ability of each strain is concerned, have been discussed in relation to genetic control.
Marginal attack rate, k‐values and density dependence in the analysis of contemporaneous mortality factors
Authors: Elkinton J. S. , Buonaccorsi J. P. , Bellows T. S. , Van Driesche R. G.
Published: October 2006

Procedures for calculating the marginal attack rates and associated k‐values from observed death rates are presented for contemporaneous predators or parasitoids that either do or do not discriminate against previously parasitized hosts.

The relationships among previous methods for quantifying contemporaneous mortalities are discussed.

Solutions to the problem of calculating marginal rates taken from human survival analysis are given under the assumption of proportional hazards. These calculations are easily extended to three or more contemporaneous sources of mortality.

The conditions under which proportional hazards can be expected are discussed.

These methods are compared to that of Varley et al., 1973 for assessment of density dependence among contemporaneous predators.
Life tables and population parameters of the green leafhopper, Nephotettix cincticeps (Uhler), in the southwestern district of Japan with special reference to the first generation on foxtail grass
Authors: Widiarta I Nyoman , Fujisaki Kenji , Nakasuji Fusao
Published: October 2006

The three year (1988–1990) life tables of Nephotettix cincticeps were constructed, and the daily survival rate and longevity of female adults were estimated by Hokyo and Kiritani's (1967) method for the overwintering and the first‐generations on the foxtail grass in Okayama, southwestern Japan. The life tables and the population parameter values estimated were compared with those in the other generations on rice. The FARMCOP suction sampler was employed to survey the population density.

The durations of pre‐ovarial maturation of female adults of the 1st generation on foxtail grass and rice seedling were similar. Longevity of adults of the overwintering and the first generations which emerged on the wild host was longer than that of the other generations (2nd and 3rd generations) on the rice plants. Fecundity of females decreased successively as the generation proceeded and it became lowest in the final 3rd generation.

Only about 3.5 percent of first‐instar nymphs of the 1st generation emerged as adults in the fallow field. The survival rate of nymphs on foxtail grass was always lower in comparison with that on rice plants. However, the survival rates of nymphs on foxtail grass and rice seedling were not significantly different from each other under laboratory conditions. In the fields, senescence of foxtail grass occurred in the midst of nymphal period of the 1st generation. The survival rate of nymphs on foxtail grass decreased with the increasing in the nymphal density. Abundance of spiders during the 1st generation was higher than that in the early stage of rice plants.
Anopheles culicifacies giles: Adult ecological parameters measured in rural punjab province, pakistan using capture‐mark‐release‐recapture and dissection methods, with comparative observations on An. stephensi liston and An. subpictus grassi
Authors: Reisen William K. , Mahmood Farida , Azra Khawar
Published: October 2006

Dispersal, immigration and emigration rates, horizontal and vertical survivorship and absolute population size were estimated for micropopulations of An. culicifacies, An. stephensi and An. subpictus at a series of cattle sheds in rural Punjab Province, Pakistan, during November 1979 and May 1980 using capture‐mark‐release‐recapture and dissection methods. Dispersal was temperature‐related, with populations more vagile during May. Mean dispersal distance per individual was low for all species. More than 70% of all recaptures were taken at the point of release and the longest detected flight was 1250 meters.

Horizontal survivorship was greater during November and was always less than vertical survivorship calculated from dissection agegrading data. Survivorship during the nulliparous period was greater than survivorship throughout total life, indicating the survivorship curve may be slightly sigmoid. Daily population sizes of endemic and immigrating females and males were calculated usingBailey's (1952) modification of the Lincoln Index, with the daily captures adjusted for immigration which was highest in May. Daily additions to the indoor resting population exclusive of immigrants were estimated using the method ofManly andParr (1968). The relationship of the present findings to malaria transmission and genetic control were discussed.
Lifetime mating success of males in a natural population of the papilionid butterfly, Atrophaneura alcinous (Lepidoptera: Papilionidae)
Authors: Suzuki Nobuhiko , Matsumoto Kazuma
Published: October 2006

Lifetime mating success of males in a natural population of the papilionid butterfly, Atrophaneura alcinous, was investigated and causes of the variation were examined. The most successful males mated with 5 females, whereas about 73% of the males failed to mate. Body size of males was not correlated with their eclosion date, longevity and lifetime mating success. There was no trade‐off between mating success and longevity, and long‐lived males had a disproportionately high mating success. Although number of available females per male per day was not variable among males with different longevities, long‐lived males had higher mating efficiency. Time interval between matings by non‐virgin males was shorter than that from eclosion to the first mating. High lifetime mating success of long‐lived males was strongly related to their mating experience, not to their age per se.
Sectors of activity, topography, and parasitism in home areas of New Guinea coarse‐haired rats, and Trombiculidae (Acarina)
Authors: Mohr Carl O.
Published: October 2006

Home areas of hosts are, in effect the gardens in which parasite populations grow. The parasites flourish in response to the kind and amount of host activity modified, of course, by the habitat, and become microcommunities supported by their host and its artifacts. When scatter diagrams of points at which hosts have been observed are divided by median major and minor axes, and when the resulting four quarters, designated A, B, C, D, corresponding to concentration of points in the quarters, the relative concentration usually is: A>B>C>D. The concentration of observed points also is generally greatest nearest the major axis and frequently, but not always, near the median center. Nests of hosts, hence nest‐parasites, appear generally to be near the center. For the host examined in detail here, the New Guinea coarse‐haired rat, most Leptotrombidium deliensis appear to have been acquired in the AB sector of the host's home areas but a greater diversity of chiggers is acquired in the CD sector. It is postulated that, if L. akamushi had been present, it would have occurred in the CD sector where, though the observed concentration of host activity was least, the mixed grassforb and shrub habitat would have been more suitable than in the AB sector. Gahrliepia pingue, C. ewingi, Schoengastia blestowei and S. schueffneri, appear also to be more abundant in the CD sector than in the AB sector. The chiggers themselves have home clusters, or lairs, and adjacent areas of activity (home areas) somewhat resembling those of the hosts.
Studies on interspecies competition between the azuki bean weevil, Callosobruchus chinensis, and the southern cowpea weevil, C. maculatus II. Competition under different environmental conditions
Authors: Fujii Koichi
Published: October 2006

The experimental studies was done on the interspecies competition between the azuki bean weevil, Callosobruchus chinensis, and the southern cowpea weevil, C. maculatus, under the different environmental conditions.

At 30°C, 70% R. H., the change of food replenishment interval had no influence upon the competition results, and the competition always ended in the extinction of C. maculatus. But there was a tendency for the period of co‐existence to be elongated as the interval of replenishment lengthened.

At 30°C, 70% R. H., there were no differences in the competition processes and results between the competition using the dry bean (water content about 11%) or the normal one (about 15%).

At 32°C, 64% R. H., the competition result was reversed from that at 30°C, 70% R. H. This is thought to be due to the differences of the developmental rates and the numbers of eggs oviposited between the two species at these conditions.

In some cases the competition result could be understood from the point of the phenomena of single species populations of both species, but in other cases, the results were in conflict with the expectation from those phenomena. To analyze the competition mechanism, it is necessary to investigate the interaction between species.
Evolution and physiological consequences of de‐alation in crickets
Authors: Tanaka Seiji
Published: October 2006

Wing shedding or de‐alation is a common phenomenon among crickets. Its significance and effects on other traits were examined based on the results from experiments using artifical or natural de‐alation. Artificial de‐alation at adult emergence induces rapid egg production and flight muscle histolysis in several species examined. However, natural de‐alation does not always shorten the pre‐ovipositional period because it does not occur immediately after adult emergence and because oviposition starts before de‐alation. In some cases, naturally de‐alated females produce more eggs than to intact females during early adult life, but peak ovipositing activity occurs before de‐alation. Therefore, retention of the hindwings does not suppress high ovipositing activity in such cases. It appears that de‐alation is a result rather than a causal factor in ending migration. Ovarian development and flight muscle histolysis, which can be stimulated by de‐alation, are controlled by the jevenile hormone, but the mechanism inducing de‐alation remains unknown. The possible factors leading to the evolution of de‐alation are discussed.
Inbreeding effects on competition in Tribolium
Authors: Craig David M. , Mertz David B.
Published: October 2006

When replicate cultures of T. confusum and T. castaneum are husbanded together under identical treatment conditions, sometimes T. confusum eliminates T. castaneum, and other times, T. castaneum wins (i.e., competitive indeterminacy occurs). While several plausible explanations were advanced, the results of Mertz et al. (1976) implicated demographic stochasticity and not classical genetic founder effect as the predominant factor influencing the identity of the winning species. They also observed, however, that the size of the founding population had an influence on the competitive strength of T. castaneum. The present study shows that the decline in competitive strength that accompanied decreasing founder size in T. castaneum can be amply explained by simple inbreeding depression. The eggs of inbred adults showed an approximate 15% reduction in hatchability when compared to outbred adults. No evidence was found that the decrease in competitive strength was due either to prior history differences or reduced genetic heterogeneity of the founding adults.
Age distribution, sex ratio and mortality of the red fox Vulpes vulpes in Tochigi, central Japan: an estimation using a museum collection
Authors: Takeuchi Masahiko , Koganezawa Masaaki
Published: October 2006

One hundred and thirty carcasses of the red fox were collected in Tochigi Prefecture, by the Tochigi Prefectural Museum, from 1981 to 1991. The young/adult ratio of the sample was 1.60, which suggests that the hunting pressure has been relatively low in this area. Six percent of the animals were 5 years or older which compares to those taken in Hokkaido, but is higher than those in Europe and North America. The sex ratio for all specimens had a tendency towards male bias (0.587), but this bias was higher for the adult (0.605) than for the young (0.576). Among young (0 year‐old) foxes, more individuals were killed on roads than by trapping or shooting (P<0.02, chisquare test). This mortality pattern was caused by high mortality of young males (P<0.02). The proportions of adults killed by the three mortality factors were similar, though only one of the 14 foxes older than 4 years old was shot, probably due to age‐linked activity patterns. Most road‐kills of young foxes occurred in May when juveniles began exploiting and in November when sub‐adults began dispersal. The ratios of road‐kills for the whole sample and for adults alone were 42% and 34%, respectively. These high rates of road‐kills suggest that the mortality pattern in Tochigi has been affected by factors characteristic of urban environments.
Comparison of life tables between the solitary eumenid wasp Anterhynchium flavomarginatum and the subsocial eumenid wasp Orancistrocerus drewseni to evaluate the adaptive significance of maternal care
Authors: Itino Takao
Published: October 2006

I compared life tables between the solitary eumenid wasp Anterhynchium flavomarginatumSmith and the subsocial eumenid wasp Orancistrocerus drewseniSaussure in Kyoto, Japan, during 1980–1983. The subsocial eumenid is parthenogenetic in this study area. There were 9 identified mortality factors in the solitary eumenid and 7 in the subsocial eumenid, 6 of which were common to the two eumenids. The important differences of mortality between the two eumenids were seen in the egg, larval, and prepupal stages. In the egg stage, mortality by the phorid fly Megaselia sp. was much lower in the subsocial eumenid (1.4%) than in the solitary eumenid (15.0%) likely because of the matenal care of the subsocial eumenid (progressive provisioning and other related behavior), which reduced predation pressure. In the larval stage, mortality by the miltogrammine fly Amobia distorta was also lower in the subsocial eumenid (8.1%) than in the solitary eumenid (23.8%) also probably because of the maternal care of the subsocial eumenid. A comparison of mortality in the two eumenids between the stable, long continuing natural nest sites and the additional temporal ones showed that the phorid fly remained near its birth place and parasitized stable nest sites. The miltogrammine fly followed returning eumenid wasps and parasitized those nest sites that have a high host density. In the prepupal stage, mortality by endogenous death was higher in the subsocial eumenid than in the solitary eumenid. Mortality due to the rhipiphorid beetle was also higher in the subsocial eumenid probably due to more frequent flower‐visits by the subsocial eumenid.

The defense mechanism of the subsocial eumenid was discussed in relation to the evolution of subsociality.
Niche modification and stability of competitive systems. II. Persistence of interspecific competitive systems with parasitoid wasps
Authors: Shimada Masakazu
Published: October 2006

Effects of niche shift in ecological time scale on the population dynamics of competing species were studied in the experimental populations of two parasitoid wasp species, Anisopteromalus calandrae and Heterospilus prosopidis (both are solitary parasites), on a host, the azuki bean weevil, Callosobruchus chinensis. Four resource conditions were set up with combination of kind of bean (azuki or black eye), and host distribution (uniform or clumped). In each resource condition, four developmental stages of hosts were provided as a resource spectrum for parasitoid wasps.

Population dynamics of the two wasp populations were investigated in each resource condition in Multi‐Generation Competitive Systems (MGCS), in which fresh hosts of four developmental stages were periodically introduced and were parasitized competitively by the two wasp species. Competitive coexistence of both wasps occurred in the azuki‐clumped condition, where the peaks of the resource utilization curves separated in the two species; pupae in A. calandrae and the early or late fourth instar in H. prosopidis, A. calandrae was eliminated in the azuki‐uniform condition and H. prosopidis went extinct in two black eye conditions irrespective of host distributions. The degrees of overlap of the resource utilization patterns of the two wasp species during population dynamics were not significantly different among resource conditions irrespective of the results of coexistence or extinction. Even in the azuki‐clumped condition, however, extinction of A. calandrae was observed when resource partitioning could not be realized with only the late fourth instar larvae available to wasps. Further analytical experiments showed that parasitizing ability of A. calandrae increased with host density per bean with azuki beans, but A. calandrae could express higher parasitizing ability with black eye beans than H. prosopidis irrespective of host density per bean.

The flexibility in parasitizing ability by A. calandrae for various host stages under different resource conditions was thought to be the major factor in determining the competitive coexistence or the extinction of either species under different resource conditions. The present experiments also suggested that different second‐best host stages between competitors could be a major contributing factor to competitive coexistence.
Group predatory behavior by the assassin bug Agriosphodrus dohrniSignoret (Hemiptera: Reduviidae)
Authors: Inoue Hiroshi
Published: October 2006

Nymphs of Agriosphodrus dohrniSignoret (Reduviidae) have a strong gregariousness and show group predatory behavior. This study was conducted to clarify adaptive significance of group predation of this species, including laboratory observations and 6‐year field surveys.

In the laboratory, observations on both solitary and group attacking against armyworms were made at varying prey size classes to compare the capture success rate by solitary predators with that by groups. The efficiency in capturing the prey was significantly higher in group attacking at any prey size class compared.

Data obtained from the field surveys indicated the tnedency for searching nymphs to feed in group and to increase the number of predators feeding per prey item with increasing prey size. Average sizes of prey captured were also larger in group feeding throughout the nymphal stage. In particular, it was remarkable that, when prey were “creeping” types, the upper size limit of prey eaten was dramatically increased.
Population dynamics of the japanese clouded apollo Parnassius glacialisbutler (Lepidoptera: Papilionidae). I. changes in population size and related population parameters for three successive generations
Authors: Matsumoto Kazuma
Published: October 2006

Population dynamics of a univoltine butterfly Parnassius glacialis (Lepidoptera: Papilionidae) was studied with mark‐recapture methods for three successive generations in a hilly region in Kanazawa City, Ishikawa Prefecture, Japan in 1981–1983.

Jolly (1965) andSeber's (1973) method was applied to the mark‐recapture data to estimate population parameters (daily survival rate, longevity, population size, sex ratio, etc.).

Sampling ratios were at least 50% and 30% for males and females, respectively.

Mean daily survival rate for males ranged 0.81–0.86 and that for females 0.80–0.84. Mean longevity was about 4–7 days for the males and about 5 days for the females. Spiders killed more males than females. Maximum longevity for an individual recorded during the study was 31 days for males and 18 days for females.

Emergence of the butterflies was later and less synchronous in 1981 than in 1982 and 1983. This was thought to be due to later extinction of heavier snow in 1981 than in the other years.

The population remained relatively stable for the three successive generations, with estimated total numbers of 914, 1277, and 869.

Estimated sex ratio (% females) was 30–40% at emergence
On the nature of errors involved in estimating stage‐specific survival rates by Southwood's method for a population with overlapping stages
Authors: Sawyer A. J. , Haynes D. L.
Published: October 2006

This paper has examined the effect of within‐stage mortality on the estimation of stage‐specific survival rates bySouthwood's (1978, p. 358) method. As pointed out bySouthwood, both the severity and timing of mortality affect the mean duration of a life stage, and consequently the estimate of the number of individuals entering that stage. Knowledge of the form of the survivorship curve permits correction of the estimate under certain circumstances. The use ofSouthwood's method with two overlapping stages having different rates and patterns of mortality leads to complex errors in the estimation of survival for the first stage. The nature of these errors is examined analytically and via a simulation model.Southwood's method is fairly robust, with moderate differences in mortality rates leading to acceptable errors in estimating survival for the first stage. When both the rate and pattern of mortality in both life stages are the same, then the survival estimate is made without error. Precise estimates of stage‐specific survival will not usually be possible withSouthwood's method because of the errors introduced by the very parameters being measured. Direct measurement of mortality rates and survivorship patterns (seeSouthwood, 1978, p. 309) is strongly advised, at least in preliminary work.
A model for analyzing insect stage‐frequency data when mortality varies with time
Authors: Bellows T. S. , Ortiz M. , Owens J. C. , Huddleston E. W.
Published: October 2006

A model is developed for the analysis of insect stage‐frequency data which may be applied to populations with age‐dependent mortality. The analysis of stage‐frequency data is divided into two steps. In the first step, the number of different mortality rates and their values are estimated. The second step provides estimates of developmental rates and variances for each developmental stage and in addition provides estimates of the number of recruits to each stage. The model may be used both in analysis and prediction of insect stage frequencies. Hence, in addition to estimating developmental and mortality rates from stage‐frequency data, it may also be used as a simulation model for an insect population. The model is applied to two populations of Hemileuca oliviaeCockerell, a lepidopterous pest of New Mexico grasslands. The model identifies, in the two populations, different mortality rates that are related to plant productivity.
Population dynamics of a migrant skipper butterfly Parnara guttata (Lepidoptera: Hesperiidae) II. Survival rates of immature stages in paddy fields
Authors: Nakasuji Fusao
Published: October 2006

Survival rates and mortality factors of a migrant skipper Parnara guttata were censused in paddy fields in 4 localities of central and western Japan during 1975–1980, and 10 life tables were developed for 3 generations. Mortality rates of eggs, older larvae and pupae were high but those of younger larvae were very low. The high mortality rate was caused by parasitoids. Ten primary and 6 secondary parasitoids were recorded. Out of three egg parasitoids, Telenomus sp. was predominant. Larval parasitoids, Apanteles baoris and Pediobus mitsukurii which are specific to genus Parnara were predominant in wet land habitat, i.e. paddy land. On the other hand, tachinid flies which have a wide host range and a high searching ability were predominant in dry land habitats. Mortalities of eggs and pupae contribute more to the change in the total mortality of immature stages than those of other stages. egg parasitoids which are the major mortality factor of eggs acted density‐dependently but larval and pupal parasitoids did not do so. The total mortality of immature stages occurred more or less density‐dependently. Larval density on rice plants scarecely affected the survival rate of larvae.
Systems analysis of an acarine predator‐prey system II: Interactions in discontinuous environment
Authors: Fujita Kazuyuki
Published: October 2006

An acarine predator‐prey system in a circular stepping‐stone environment was described with a simulation model to elucidate the factors responsible for persistence of the system. The main assumptions in this model are: (1) The prey are inevitably eliminated in patches in which predators exist. (2) The density of prey declines and becomes extinct by plant defoliation due to feeding by prey. In this regard this model is different from the models which mimickedHuffaker's (1958) experiments and assumed stable plant‐prey relations.

Analyses showed that the critical factor in persistence of the predator‐prey system was the plant‐prey relations, at any combination of other parameters involved in the model. The predator‐prey system did not persist long under the unstable relationship of prey and plant. Otherwise the system persisted longer especially when I used a larger number of patches, a larger amount of plant in each patch, and long‐distance‐migrations of the prey. In particular, frequent emigration of the prey regardless of plant conditions was most effective.
Estimating developmental and mortality rates and stage recruitment from insect stage‐frequency data
Authors: Bellows T. S. , Birley M. H.
Published: October 2006

A model for the analysis of insect stage‐frequency data is developed which includes stage‐specific variable developmental periods and stage‐specific daily survival rates. The model can predict the development of an insect population through its developmental stages and consequently may form the basis for a simulation model of the population.
The structure and behavior of defoliating insect/forest systems
Authors: McNamee P. J. , McLeod J. M. , Holling C. S.
Published: October 2006

Using four detailed and complex simulation models we derive a framework for predicting behavior of any defoliating insect/forest system. The framework uses simple and easily gathered biological information on four sets of state variables, each with a characteristic temporal scale, to predict presence, absence or form of key ecological processes acting on or between the variables. The combination of these key processes enables prediction of system equilibrium structure and this structure can be used to derive the temporal behavior of the system. Four qualitatively different classes of system behavior arise from the equilibrium structures.

The framework is tested against twelve other systems and field invalidation experiments are outlined. Forest defoliator research and management implications are discussed.
Spatial relationships between mate acquisition probability and aggregation size in a gregarious coreid bug, (Colpula lativentris): A case of the ideal free distribution under perceptual constraints
Authors: Nishida Takayoshi
Published: October 2006

Spatial relationships of mate acquisition probability for individuals of both sexes of a gregariously‐mating coreid bug, Colpula lativentris, were studied in relation to aggregation size. Operational sex ratio was always strongly male biased. Mate acquisition probability of females was rather constant and independent of aggregation size, as predicted by an ideal free distribution. Moreover laboratory experiments showed that both multiple mating and rearing density little affected female fecundity, suggesting ideal free distribution of females in terms of reproductive success. On the other hand, mate acquisition probability of males was higher in larger aggregations, where more receptive females were available. This male discrepancy from an ideal free distribution was similar to the patterns predicted by an ideal free distribution under perceptual constraints (Abrahams, 1986), but not by that under unequal competitive ability.
Automated Solutions for Total RNA Isolation from Diverse Sample Types
Authors: Selley Paula , Bruner Jimmy , Kelly Fiona , Maurio Frank , Waters Michelle , Strum Jay
Published: October 2006

In response to the increasing demands to generate larger amounts of quality data faster, specifically in the area of RNA isolation to support gene expression assays, we have adopted several automated solutions for isolating total RNA from a variety of sample types, e.g., blood, cells, and tissue. For isolation from blood, collected in PAXgene (PreAnalytiX, Hombrechtickon, CH) tubes, we use a Qiagen BioRobot Universal System (Qiagen Inc-USA, Valencia, CA). For total RNA from cells, we have adapted a 96-well plate solid-phase extraction method using Promega SV96 (Promega, Inc., Madison, WI) reagents. Finally, if starting from tissues, we use the AutoGenPrep 245 (AutoGen Inc, Holliston, MA) robot to perform a modified acid guanidine phenol chloroform isolation. The use of the AutoGenPrep 245 is preceded by tissue homogenization, usually performed on the Qiagen TissueLyser.

Following total RNA isolation the RNA is quantified by QuantiT (Invitrogen Corporation, Carlsbad, CA) using a Biomek FX method that performs whole plate serial dilutions, and then creates a reaction plate with samples in duplicate. Finally, to check for genomic DNA contamination in the total RNA sample, a minus reverse transcription PCR assay is performed. In using these methods, we are able to increase our throughput without compromising data integrity.
Independent contributions of neural and “higher‐order” deficits to symptoms in Alzheimer's disease: A latent variable modeling approach
Authors: Tractenberg Rochelle E. , Aisen Paul S. , Weiner Myron F. , Cummings Jeffrey L. , Hancock Gregory R.
Published: October 2006

Background

Analytic models of Alzheimer's disease (AD) tend to focus on one type of symptom and assume implicitly that no measurement error is present. These tendencies render changes in symptom domains difficult to model mathematically, although latent variable methods can accommodate both multiple symptom domains and error. This study formulated and compared underlying (latent) factor structures representing previously reported dependence and independence of symptoms of cognitive decline, functional impairment, and behavioral disturbance in AD.

Methods

In confirmatory factor analyses of data from 2 cohorts of AD patients, 2 levels of latent variables were conceptualized. One general neurologic factor represented disease, and symptom factors represented cognition, function, and behavior. Two “null” models had either a single factor or 3 symptom factors. Two 2‐level models treated the general factor as underlying both the observed variables and the symptom factors or treated the symptom factors as explaining variability in the observed variables after taking the general factor into account (“residualized”).

Results/Conclusions

The residualized model fit the data in both cohorts significantly better than the other models, and relations in this model between some observed and latent variables were different across cohorts. Neither cohort supported a single factor model; both cohorts independently supported a residualized model that may permit differentiation of symptom‐ from disease‐modifying effects of treatment.
Brachial Plexus Injury in Snowboarding
Authors: OGAWA T. , OCHIAI N. , HARA Y.
Published: October 2006

This paper reports three cases of brachial plexus injury which occurred during snowboarding.
Septic Arthritis of the Small Joints of the Hand
Authors: SINHA M. , JAIN S. , WOODS D. A.
Published: October 2006

Twenty-five patients with sepsis of 26 hand joints were treated by urgent debridement, antibiotics and early hand therapy. We reviewed 15 patients (16 joints) in a clinic and three patients by postal questionnaire after a mean follow-up of 54 (range 10–94) months. Of the 26 involved joints, 14 had restricted motion at discharge. Stiffness increased with increase in delay between onset and treatment. At final review, one joint with painful degenerative changes had been fused. Seven patients had regained full movements. The remaining six had some stiffness but, nevertheless, had undergone significant improvement in the ranges of movement. There were two cases with radiological joint degeneration in this group of six patients. Three patients had mild, intermittent pain. No patient had significant disability. While there is significant loss of motion after this joint pathology in the early recovery period, overall motion and function appears to improve over the longer term.
Dynamic market entry and the value of flexibility in transitional international joint ventures
Authors: Lukas Elmar
Published: October 2006

The purpose of this study is to formalize the optimal choice of market entry strategy for an individual multinational enterprise (MNE) from a dynamic perspective. It is argued that incorporating a suitable treatment of irreversibility, uncertainty and flexibility related to an MNE's investment decision gives further insights into the expansion, dissolvement, and optimal timing of international joint ventures (IJVs). In most cases, the initial entry strategy serves as a platform allowing the firm to make subsequent investments to exploit host‐country advantages and capabilities. We allow for this by taking a three‐step expansion strategy explicitly into account. The evolutionary process of the value of the foreign direct investment can be interpreted as a compound complex chooser option. The results suggest that uncertainty, size of equity share and future investment/divestment opportunities play an important role when it comes to transit from export to the first phase of the foreign direct investment commitment. The paper underscores the importance of modeling the dynamics of market entry and helps to refine the application of real options in the alliance context by providing a closed‐form solution in continuous time to value the overall strategic flexibility.
Dusty weather forecasts using the MesoNH mesoscale atmospheric model
Authors: Grini Alf , Tulet Pierre , Gomes Laurent
Published: October 2006

Several studies have shown the importance of aerosols in the Earth's radiative balance. The radiative effect of dust has earlier been quantified in global and regional climate models. Fewer studies have included prediction of aerosols online in numerical weather prediction (NWP) models. Predicting climate effect of aerosols is different from including aerosols actively in weather prediction because climate models give average responses over long timescales, whereas the purpose of weather prediction models is to calculate the right weather on short timescales. In this paper, we run a mesoscale NWP with four different assumptions on dust aerosols: (1) no dust, (2) climatological data set for dust aerosols, (3) forecasted dust using the Dust Entrainment and Deposition model (DEAD) and (4) same as assumption 3 but with decreased single scattering albedo. We show that the assumption on dust is important for predicting ground temperature and convective precipitation in the model. Dust changes the model physics through changing the radiative fluxes. We interpret the changes through analyzing the energy budgets for four zones close to the major dust sources. The zones include both convective and nonconvective areas. In convective areas over ocean, dust can decrease convective activity. The vertical gradient of the aerosols and their single scattering albedo determine how efficient they are. Over land, dust also influences the surface energy budget so that decreased latent heat fluxes result if dust plumes pass over areas where water evaporates from the surface.
Magnetospheric energy budget during huge geomagnetic activity using Cluster and ground‐based data
Authors: Rosenqvist L. , Buchert S. , Opgenoorth H. , Vaivads A. , Lu G.
Published: October 2006

The Cluster spacecraft crossed the magnetopause at the duskward flank of the tail while the European Incoherent Scatter (EISCAT) radars and magnetometers observed the ionosphere during a sequence of intense substorm‐like geomagnetic activity in October 2003. We attempt to estimate the local and global energy flow from the magnetosheath into the magnetotail and the ionosphere under these extreme conditions. We make for the first time direct observational estimates of the local solar wind power input using Cluster measurements. The global power input based on Cluster observations was found to be between 17 and 40 TW at the onset of the substorm intensification. However, spacecraft observations and global modelling of the magnetotail suggest that it is most probably closer to 17 TW. This is more than two times lower than the predicted ε parameter value (37 TW). Energy deposition in the ionosphere has been estimated locally with EISCAT and globally with the assimilated mapping of ionospheric electrodynamics (AMIE) technique. The amount of the global solar wind power input (17 TW) that is dissipated via Joule heating in the ionosphere is found to be 30%. The corresponding ratio based on empirical estimates is only 3%. However, empirical proxies seem to underestimate the magnitude of the Joule heating rate as compared to AMIE estimates (∼ a factor 4) and the ε parameter is more than twice as large as the Cluster estimate. In summary, the observational estimates provide a good balance between the energy input to the magnetosphere and deposition in the ionosphere. Empirical proxies seem to suffer from overestimations (ε parameter) and underestimations (Joule heating proxies) when pushed to the extreme circumstances during the early main phase of this storm period.
Response of monsoon precipitation in the Himalayas to global warming
Authors: Duan Keqin , Yao Tandong , Thompson Lonnie G.
Published: October 2006

Reconstruction of annual net accumulation using ice cores from the Dasuopu glacier reveals monsoon precipitation variability in the central Himalayas over the past three centuries. We found that the broad features of the snow accumulation are reverse to the Northern Hemisphere temperature reconstruction over the past 300 years. On average, a 0.1°C change in Northern Hemisphere temperature is associated with about 100 ± 10 mm change in snow accumulation in the Dasuopu ice core. Especially during the period 1920–1995 the snow accumulation in the Dasuopu ice core decreased about 500 mm while Northern Hemisphere temperature increased about 0.5°C, which contrasts with previous studies that indicate an increase of summer monsoon precipitation in High Asia is a consequence of global warming. For the period 1900–1995 Indian monsoon precipitation in the Himalayas, Nepal, Bangladesh and northern India highly correlate with the thermal contrast between the Tibetan Plateau and the tropic Indian Ocean. Although the Tibetan Plateau has experienced statistically significant warming until to the early 1960s, the linear warming trend on the Tibetan Plateau is still less than that in the tropical Indian Ocean during the period 1900–1995, suggesting a decreasing thermal contrast between the Tibetan Plateau and the tropical Indian Ocean. We infer that transportation of water vapor from the tropical Indian Ocean to the Himalayas is decreasing as a result of the decreasing thermal contrast between the Tibetan Plateau and the tropical Indian Ocean.
Advances in neutral-beam-based diagnostics on the Madison Symmetric Torus reversed-field pinch (invited)
Authors: Den Hartog D. J. , Craig D. , Ennis D. A. , Fiksel G. , Gangadhara S. , Holly D. J. , Reardon J. C. , Davydenko V. I. , Ivanov A. A. , Lizunov A. A. , O’Mullane M. G. , Summers H. P.
Published: October 2006

Innovative charge-exchange recombination spectroscopy (CHERS), motional Stark effect (MSE), and Rutherford scattering diagnostics are now in operation on the Madison Symmetric Torus (MST) reversed-field pinch (RFP). The CHERS diagnostic measures impurity ion flow and temperature, localized to 2cm with high time resolution (∼100kHz). A spectral MSE diagnostic has been in use for five years, measuring ∣B∣ down to 0.2T with high precision (∼2%) and good time resolution (10kHz). The Rutherford scattering diagnostic has demonstrated the robustness of this technique for reliable measurement of majority (D) ion temperature, also with high time resolution. MST is a large RFP (R=1.5m, a=0.52m) operated at moderate current (Ip⩽600kA), with ne typically (1–2)×1019m−3 and Te, Ti⩽2keV. Two compact and reliable diagnostic neutral beams are installed on MST. These beams are short pulse, intense, monoenergetic, and low divergence. The first, a neutral H beam, is used in combination with ultraviolet and visible spectroscopy to make the CHERS and MSE measurements. For CHERS, the CVI line at 343.4nm is collected by a custom high-throughput double grating spectrometer which simultaneously records both charge-exchange and background emissions. The spectrum is analyzed using a sophisticated model derived from the Atomic Database and Analysis Structure (ADAS) package. The MSE system records the entire Hα Stark spectrum; ∣B∣ is derived from the measured splitting of the π+ and π− manifolds. Measurement of ∣B∣ is critical to accurate equilibrium reconstruction in the RFP. The second diagnostic beam is a 20keV neutral He beam and is used for the Rutherford scattering measurements. A pair of neutral particle analyzers is used to record the energy spectrum of the small-angle Rutherford scattered He atoms.
Fiber optic two-color vibration compensated interferometer for plasma density measurements
Authors: Van Zeeland M. A. , Boivin R. L. , Carlstrom T. N. , Deterly T. , Finkenthal D. K.
Published: October 2006

A fiber optic, heterodyne, two-color interferometer utilizing wavelength division multiplexing technology has been developed for measuring electron density in plasmas. Vibration compensation is accomplished via common path 1.31 and 1.55μm distributed feedback laser interferometers. All beam combining, splitting, frequency modulation, and collimation are accomplished by shared single-mode fiber optic components. Measurements of an argon radio-frequency generated plasma with electron densities of 1020m−3 show effective vibration compensation and typical line-density resolution of approximately 2×1019m−2.
Extracting effective normal modes from equilibrium dynamics at finite temperature
Authors: Martinez M. , Gaigeot M.-P. , Borgis D. , Vuilleumier R.
Published: October 2006

A general method for obtaining effective normal modes of a molecular system from molecular dynamics simulations is presented. The method is based on a localization criterion for the Fourier transformed velocity time-correlation functions of the effective modes. For a given choice of the localization function used, the method becomes equivalent to the principal mode analysis (PMA) based on covariance matrix diagonalization. On the other hand, a proper choice of the localization function leads to a novel method with a strong analogy with the usual normal mode analysis of equilibrium structures, where the Hessian system at the minimum energy structure is replaced by the thermal averaged Hessian, although the Hessian itself is never actually calculated. This method does not introduce any extra numerical cost during the simulation and bears the same simplicity as PMA itself. It can thus be readily applied to ab initio molecular dynamics simulations. Three such examples are provided here. First we recover effective normal modes of an isolated formaldehyde molecule computed at 20K in very good agreement with the results of a normal mode analysis performed at its equilibrium structure. We then illustrate the applicability of the method for liquid phase studies. The effective normal modes of a water molecule in liquid water and of a uracil molecule in aqueous solution can be extracted from ab initio molecular dynamics simulations of these two systems at 300K.
Colloidal electroconvection in a thin horizontal cell. II. Bulk electroconvection of water during parallel-plate electrolysis
Authors: Han Yilong , Grier David G.
Published: October 2006

We recently have reported [J. Chem. Phys. 122, 164701 (2005)] a family of electroconvective patterns that arise when charge-stabilized colloidal dispersions are driven by constant (dc) vertical electric fields. Competition between gravity and electrokinetic forces acting on the individual spheres in this system leads to the formation of highly organized convective instabilities involving hundreds of spheres. Here, we report a distinct class of electroconvective patterns that emerge in confined aqueous dispersions at higher biases. These qualitatively resemble the honeycomb and labyrinthine patterns formed during thermally driven Rayleigh-Bénard convection, but arise from a distinct mechanism. Unlike the localized colloidal electroconvective patterns observed at lower biases, moreover, these system-spanning patterns form even without dispersed colloidal particles. Rather, they appear to result from an underlying electroconvective instability during electrolysis in the parallel plate geometry. This contrasts with recent theoretical results suggesting that simple electrolytes are linearly stable against electroconvection.
First-principles study of intermediate size silver clusters: Shape evolution and its impact on cluster properties
Authors: Yang M. , Jackson K. A. , Jellinek J.
Published: October 2006

Low-energy isomers of AgN clusters are studied within gradient-corrected density functional theory over the size range of N=9–20. The candidate conformations are drawn from an extensive structural database created in a recent exploration of CuN clusters [M. Yang et al., J. Chem. Phys. 124, 24308 (2006)]. Layered configurations dominate the list of the lowest-energy isomers of AgN for N<16. The most stable structures for N>16 are compact with quasispherical shapes. The size-driven shape evolution is similar to that found earlier for NaN and CuN. The shape change has a pronounced effect on the cluster cohesive energies, ionization potentials, and polarizabilities. The properties computed for the most stable isomers of AgN are in good agreement with the available experimental data.