bluuebunny/crossref_metadata_2025_split huggingface dataset:
The dynamics of egg production, oviposition and resorption in a parasitoid wasp
Authors: RIVERO‐LYNCH A. P. , GODFRAY H. C. J. 
Published: December 2004

1. The extent to which parasitoid wasps are limited by their egg supply is very important in understanding their reproductive strategies. Egg reserves are dynamic, with most wasps maturing new eggs throughout their life (synovigeny) and many species resorbing eggs that are not used in oviposition. We investigated the extent to which a parasitoid modulates its egg reserves in the light of its experience in finding hosts. 2. The egg dynamics of the Encyrtid Wasp Leptomastix dactylopii, a solitary parasitoid of mealybugs, were studied in the laboratory. This species is synovigenic and practises egg resorption. 3. We allowed newly emerged wasps to experience one of four environments of increasing value in terms of reproductive opportunities. We proposed that wasps that experienced good quality environments would maintain more mature eggs ready for oviposition. Dissection of wasps subject to different periods of host deprivation after the experimental treatment failed to confirm the hypothesis: egg load was independent of experience. 4. We also proposed that any adjustment of egg supply to make up for eggs oviposited would be effected through a reduction in egg resorption. Instead, we found that the wasp quickly made up for eggs oviposited by increased egg production.
The effects of substrate and vertebral number on locomotion in the garter snake Thamnophis elegans
Authors: KELLEY K. C. , ARNOLD S. J. , GLADSTONE J. 
Published: December 2004

1. Locomotor performance of limbless vertebrates depends on the substrate through which individuals move and may result in selection on vertebral number in different habitats. To evaluate the effect of push‐point density on snake locomotion, the density of vegetation and other potential push‐points was quantified at two sites in California (coastal and inland), where conspecific snakes differed greatly in vertebral number (230 and 256 average total vertebrae, respectively; Arnold 1988). The coastal site had significantly higher push‐point densities than the inland site. 2. Five experimental push‐point densities that fell within the natural range of push‐point densities were employed in laboratory trials of juvenile snake locomotion. Density of push‐points significantly affected both crawling speed and head‐to‐tail distance (HTD), an indirect measure of lateral bending. The fastest speed was achieved at an intermediate push‐point density. The shortest HTD occurred when snakes moved through the lowest push‐point density. 3. Sex, total number of vertebrae and total length significantly affected HTD, regardless of push‐point density. Snakes with relatively more vertebrae had a shorter HTD, suggesting they were able to achieve greater lateral bending than snakes with fewer vertebrae. Coastal and inland populations did not differ in HTD during locomotion. 4. Numbers of body and tail vertebrae significantly influenced speed at different push‐point densities. In general, snakes with more body vertebrae were slower than those with fewer, while snakes with more tail vertebrae were faster than those with fewer. Snakes of greater total length were faster at all densities. Coastal snakes crawled faster than inland snakes at all push‐point densities.
Limits to the distribution of the southern African Ice Rat (Otomys sloggetti): thermal physiology or competitive exclusion?
Authors: RICHTER T. A. , WEBB P. I. , SKINNER J. D. 
Published: December 2004

1. We test the hypothesis that the thermal physiology of Otomys sloggetti restricts its distribution to altitudes above 2000 m, below which it does not occur. 2. The thermal physiology of O. sloggetti is typical of rodents from warm/hot areas: the thermoneutral zone is relatively broad and lies between 26 and 28 °C; the upper limit of the thermoneutral zone can be extended by 4 °C through the use of hyperthermia; basal metabolic rate concurs with the allometrically predicted value; the lower critical temperature is high; minimal thermal conductance is 21% higher than the allometrically predicted value; and the capacity for noradrenaline‐induced non‐shivering thermogenesis is 19% lower than the allometrically predicted value. 3. Evaporative water loss and water flux rates are high and typical of mesic‐adapted rodents. 4. The absence of O. sloggetti from warmer, lower‐lying habitats cannot be attributed to its thermal physiology. We suggest that non‐physiological factors, such as interspecific competition with Otomys irroratus, are more likely to restrict the distribution of O. sloggetti.
Analysis of pollinator foraging: tests for non‐random behaviour
Authors: JONES K. N. 
Published: December 2004

1. A standardized protocol for analysing the behaviour of pollinators foraging on more than one plant type (species or morph) is needed. 2. A protocol is presented in which the first step is to test whether foraging trips are homogeneous in the frequency of visits to each plant type, or whether there are two or more groups of pollinators with different foraging preferences. 3. Tests for foraging preference and constancy in the sequence of plants visited then should be made separately for each homogeneous group. 4. A hypothetical example is given in which ignoring heterogeneity of preference would lead to the acceptance of a false null hypothesis of random behaviour. 5. A real example is given in which heterogeneity of preference was the only non‐random aspect of pollinator behaviour (no significant positive constancy or overall preference), while transfer of powdered dye particles (pollen analogues) was assortative among floral morphs. 6. Heterogeneity of preference is probable, as many factors may cause individual pollinators to forage differently on the same patch of plants, and may be sufficient to produce non‐random pollen transfer among plant morphs.
Autoregulation of Pax6 transcriptional activation by two distinct DNA‐binding subdomains of the paired domain
Authors: Yamaguchi Yuki , Sawada Jun‐ichi , Yamada Masao , Handa Hiroshi , Azuma Noriyuki 
Published: December 2004

Background: Pax6 is a transcription factor that plays a central role in eye development. Pax6 contains a DNA‐binding domain called paired domain, which consists of a highly conserved N‐terminal subdomain and a variable C‐terminal subdomain. Recent findings have suggested that both subdomains possess distinct DNA‐binding activities. Results: To understand the mechanism of DNA‐binding and transcriptional activation by Pax6 via these subdomains, we employed Pax6 paired domain mutants previously isolated from patients with ocular disorders. Analysis of these mutants by gel shift assay revealed that the N‐terminal and C‐terminal subdomains can independently bind to their respective cognate sites, P6CON and 5aCON. Results from a luciferase assay, however, showed that the two functional subdomains negatively regulate their transactivation potentials each other. Wild‐type Pax6 and its hyperactive variants show different patterns of DNA contact. Conclusion: These results support a new model for the regulation of Pax6 transactivation: When one DNA‐binding subdomain binds to its cognate site, the other subdomain also interacts with the flanking sequences nonspecifically, and this interaction constrains its structure to give a reduced level of transactivation.
Soil carbon inventories and δ13C along a moisture gradient in Botswana
Authors: Bird M. I. , Veenendaal E. M. , Lloyd J. J. 
Published: December 2004

AbstractWe present a study of soil organic carbon (SOC) inventories and δ13C values for 625 soil cores collected from well‐drained, coarse‐textured soils in eight areas along a 1000 km moisture gradient from Southern Botswana, north into southern Zambia. The spatial distribution of trees and grass in the desert, savannah and woodland ecosystems along the transect control large systematic local variations in both SOC inventories and δ13C values. A stratified sampling approach was used to smooth this variability and obtain robust weighted‐mean estimates for both parameters.Weighted SOC inventories in the 0–5 cm interval of the soils range from 7 mg cm−2 in the driest area (mean annual precipitation, MAP=225 mm) to 41±12 mg cm−2 in the wettest area (MAP=910 mm). For the 0–30 cm interval, the inventories are 37.8 mg cm−2 for the driest region and 157±33 mg cm−2 for the wettest region. SOC inventories at intermediate sites increase as MAP increases to approximately 400–500 mm, but remain approximately constant thereafter. This plateau may be the result of feedbacks between MAP, fuel load and fire frequency.Weighted δ13C values decrease linearly in both the 0–5 and 0–30 cm depth intervals as MAP increases. A value of –17.5±1.0‰ characterizes the driest areas, while a value of −25±0.7‰ characterizes the wettest area. The decrease in δ13C value with increasing MAP reflects an increasing dominance of C3 vegetation as MAP increases. SOC in the deeper soil (5–30 cm depth) is, on average, 0.4±0.3‰ enriched in 13C relative to SOC in the 0–5 cm interval.
Genetic variation in germination, growth, and survivorship of red maple in response to subambient through elevated atmospheric CO2
Authors: Mohan Jacqueline E. , Clark James S. , Schlesinger William H. 
Published: December 2004

AbstractGenetic variation in plant response to atmospheric carbon dioxide (CO2) may have influenced paleo‐vegetation dynamics and could determine how future elevated CO2 drives plant evolution and ecosystem productivity. We established how levels of relatedness – the maternal family, population, and provenance – affect variation in the CO2 response of a species. This 2‐year growth chamber experiment focused on the germination, growth, biomass allocation, and survivorship responses of Acer rubrum to four concentrations of CO2: 180, 270, 360, and 600 μL L−1– representing Pleistocene through potential future conditions. We found that all levels of relatedness interacted with CO2 to contribute to variation in response. Germination responses to CO2 varied among families and populations, growth responses depended on families and regions of origin, and survivorship responses to CO2 were particularly affected by regional identities. Differences among geographic regions accounted for 23% of the variation in biomass response to CO2. If seeds produced under subambient CO2 conditions behave similarly, our results suggest that A. rubrum may have experienced strong selection on seedling survivorship at Pleistocene CO2 levels. Further, this species may evolve in response to globally rising CO2 so as to increase productivity above that experimentally observed today. Species responses to future atmospheric CO2 and the accompanying biotic effects on the global carbon cycle will vary among families, populations, and provenances.
Control of Salmincola californiensis (Copepoda: Lernaeapodidae) in rainbow trout, Oncorhynchus mykiss (Walbaum): a clinical and histopathological study
Authors: Roberts R J , Johnson K A , Casten M T 
Published: December 2004

AbstractA stock of rainbow trout, Oncorhynchus mykiss, held at an experimental facility, was found to be heavily infested with the lernmaeapodid copepod Salmincola californiensis. The efficacy and effects of treatment were compared with ivermectin or manual removal of parasites as a means of control of S. californiensis. One group of fish was orally intubated with 0.2 mg ivermectin active ingredient kg−1 fish. A second treatment was administered after a further 14 days. In a second group of fish, parasites were manually removed from the gills using forceps. These fish were sampled for up to 21 days post‐first removal of parasites. In the ivermectin‐treated fish adult parasites became inactive and changed colour within 18 h of the initial treatment. Copepods began to disappear by day 3 post‐treatment and by day 31 almost all embedded female parasites had disappeared. Gills were clinically normal apart from cavitation deformity resulting from parasite attachment. Post‐ivermectin treatment, there was an increase in the number of eosinophilic granular cells surrounding the bulla of attached S. californiensis, but from day 31 post‐treatment these were replaced by macrophages and epithelioid cells to form a necrotic focus. In manually picked fish there was extensive haemorrhage in the interlamellar spaces as a result of parasite removal. At sites of parasite removal tissue necrosis was minimal and healing was rapid. At the end of the sampling period the structure of the gill was improved. The use of oral dosage with ivermectin is an effective treatment for S. californiensis and could be particularly beneficial for use with endangered salmon broodstocks infested with the parasite.
Presence of anti‐Neoparamoeba sp. antibodies in Tasmanian cultured Atlantic salmon, Salmo salar L.
Authors: Gross K , Carson J , Nowak B 
Published: December 2004

AbstractPrevious studies have indicated that when Atlantic salmon, Salmo salar L., are exposed to Neoparamoeba sp. the fish produce anti‐Neoparamoeba sp. antibodies. It appears unlikely that these antibodies elicit any specific protection against amoebic gill disease (AGD) as fish with demonstrable activities have been affected by AGD. Experiments were conducted on Atlantic salmon cultured throughout Tasmania to assess the natural production of antibodies towards Neoparamoeba sp. Fish were sampled from areas where AGD was prevalent and from areas where there had been no reported cases. An enzyme‐linked immunosorbent assay (ELISA) was used to measure anti‐Neoparamoeba sp. antibody activities in serum. All fish from sea water had antibody activities greater than the negative control fish, including fish from areas with no reported cases of AGD. Time trial samples indicated that time after transfer to sea water did not appear to be a significant (P > 0.05) factor in antibody activity, however location was (P < 0.05). There was no agreement (corrected κ value, 0.16) between the ELISA result and the isolation of Neoparamoeba sp. from the gills of the same fish. The results suggest that Atlantic salmon in seawater culture in Tasmania produce anti‐Neoparamoeba sp. antibodies regardless of infection history, suggesting the presence of Neoparamoeba sp. in the environment.
Issues for consideration in dihydropteridine reductase (DHPR) deficiency: a variant form of hyperphenylalaninaemia
Authors: Pogson D. 
Published: December 2004

AbstractAn adult male with intellectual disabilities demonstrated deterioration in many skills over a number of years and an increase in his temper outbursts was also reported. At 18 years of age, he had been diagnosed as having dihydropteridine reductase (DHPR) deficiency, but treatment had proved unsuccessful in the short term and was discontinued. Dihydropteridine reductase deficiency Is a recessively inherited disorder of the amino acid metabolism resulting in a deficiency of tetrahydrobiopterin, an essential cofactor for phenylalanine, tyrosine and tryptophan metabolism. This causes a severe deficiency of neurotransmitters in the brain. Following further neurological examinations, treatment for the subject was recommenced at the age of 30 years. Few reports of late‐diagnosis DHPR have been documented. This paper outlines one case report of DHPR, highlighting the importance of diagnosis, medical treatment and nursing care.
Mortality and avoidable death in people with severe self‐injurious behaviour: results of a Dutch study
Authors: Nissen J. M. J. F. , Haveman M. J. 
Published: December 2004

AbstractMortality and avoidable death was studied in a cohort of 1168 people with severe self‐injurious behaviour (SIB) in the Netherlands. Fifty‐seven people died over a 5‐year period (1990–1995). The observed mortality in the cohort studied was higher than the expected mortality. The age‐specific mortality was highest in the 30–39‐year‐old age‐group. Diseases of the respiratory system were found to be the most prevalent cause of death, followed by diseases of the nervous system and sensory organs. In six people (12%), the general practitioner and staff member considered SIB to be related to death. The causes of death were thought to be avoidable in two cases. The results are discussed in terms of data collection and avoidability of death.
Paroxetine in depressed adolescents with intellectual disability: an open label study
Authors: Masi G. , Marcheschi M. , Pfanner P. 
Published: December 2004

AbstractThe aim of this study was to evaluate the efficacy and side‐effects of paroxetine treatment in adolescents with mild intellectual disability and major depressive disorder (MDD). Seven adolescents (14.7–18.4 years of age) were treated with paroxetine (dosage 20–40 mg day−1). Clinical changes were assessed at the beginning of the pharmacological treatment and after 9 weeks utilizing the DSM‐IV diagnostic criteria and the Montgomery‐Asberg Depression Rating Scale (MADRS). Four out of the seven subjects did not fulfil the DSM‐IV diagnostic criteria after the 9‐week treatment. The mean decrease in the total score on the MADRS was significant (41%). Some items of the MADRS showed significant improvement: inner tension (66%); lassitude (55%); apparent sadness (53%); inability to feel (44%); and reported sadness (43%). Three subjects showed sedation, two subjects gastrointestinal complaints and one subject insomnia; all these symptoms were transitory and not severe. No behavioural activation was evident. This preliminary, uncontrolled study of a few cases suggests that adolescents with intellectual disability and MDD may respond to paroxetine, and that adverse side‐effects are mild.
Two cases of pachydermodactyly
Authors: Kang Byung Duk , Hong Seung Hyun , Kim Ill Hwan , Kim Woo Kyung , Oh Chil Hwan 
Published: December 2004

Case 1 A 27–year‐old man had a 15–year history of progressive, asymptomatic, fusiform swelling on fhe medial and lateral aspects of several fingers. There was no history of significant trauma and pain or arthritic symptoms. The family history was noncontributory. His mother said that he had a habit of rubbing his fingers.Physical examination revealed fusiform swellings limited to the medial and lateral sides of the proximal interphalangeal joints of the index, middle, and ring fingers of both hands (Fig. 1). These lesions were firm tumors, and the overlying skin was lichenified. He had a full range of motion of all of his joints with no tenderness. The thumbs, outer aspects of the index and little fingers, and toes were spared.The roentgenogram of the hands showed soft tissue swellings without bony or articular abnormalities. Routine laboratory findings, including complete blood count, erythrocyte sedimentation rate, urine analysis, liver function test, concentration of nitrogen in the form of urea in the blood (BUN), creatinine, blood sugar, hepatitis B antigen, venereal disease research laboratory (VDRL) test, rheumatoid factor, anti‐nuclear antibody, and chest X‐ray, were either normal or negative.An excisional biopsy was performed (Fig. 2), which revealed hyperkeratotis, acanthosis, and reticular dermis thickened by deposits of collagen. In the reticular dermis, the collagen was arranged in a haphazard array. A proliferation of thin collagen fibers encircled the adnexal structures and blood vessels. Fibroblasts which were cytologically benign were slightly increased in the lesion. Silver nitrate impregnation staining revealed an increased number of reticulum fibers in the lesion.An ultrastructural examination of the reticular dermis from the lesional and adjacent normal skin was performed (Fig. 3, Table 1), We tried to measure the diameter and size of the collagen fibers using an image analysis system (AIC Inc., Roswall, GA). Collagen fibers on the lesion were smaller in diameter and area. In the lesion, the mean collagen fiber diameter was 80.43 nm and the mean area was 6.75× 103 nm2. In the control, the mean collagen fiber diameter was 160.04 nm and the mean area was 27.83× 103 nm2. The coefficient of variation in the diameter and area of the collagen fibers revealed a higher value in the lesional site than in the normal control, indicating that the collagen fibers on the lesion were less uniform in diameter and area than those of the normal control.The patient had subcutaneous and dermal resection over the PIP joint of the right ring finger by way of trial, and has been followed up until now.
Temperature‐related divergence in experimental populations of Drosophila melanogaster. II. Correlation between fitness and body dimensions
Authors: Cavicchi Sandro , Guerra Daniela , Natali Vanna , Pezzoli Cristina , Giorgi Gianfranco 
Published: December 2004

AbstractFrom a laboratory stock of Drosophila melanogaster (Oregon), reared for more than 20 years at 18° C, a new population was derived and maintained at 28° C for 8 years. The chromosomal and cytoplasmic contribution to genetic divergence between the two populations was estimated. Six body traits and reproductive fitness were taken into account. The third chromosome is responsible for the adaptive difference for temperature between the two lines. Temperature‐selected genes which control body size are located on the second and third chromosomes, although the contribution of each chromosome depends on the environment in which the flies develop. The correlation between the chromosomal and cytoplasmic contributions to different traits and fitness, changes with temperature. At 28° C the correlation between fitness and each body trait is proportional to the response to selection exhibited by each of them, but this is not true at 18° C. Body size has, therefore, an adaptive significance in relation to temperature, which is expressed only in the environment where selection occurs. Cytoplasmic genes affect almost all characters to an extent similar to that of chromosomal genes. Inter‐chromosomal and nucleo‐cytoplasmic interactions are present and also change with temperature. In general, genes selected in a given environment produce greater phenotypic changes in that environment than in another. The population that experienced both temperatures is fitter in both environments, suggesting that the capacity to adapt to warm temperatures depends on genes other than those which are involved in the adaptation to cold.
Evolution, speciation, and inbreeding in the parasitic ant genus Epimyrma (Hymenoptera, Formicidae)
Authors: Buschinger Alfred 
Published: December 2004

AbstractThe ant genus Epimyrma exhibits an evolutionary transition from fully developed slave‐making to a completely workerless parasitic condition. Two of the actively dulotic species, like the closely‐related Myrmoxenus gordiagini, engage in mating and dispersal flights as is usual in ants, whereas in the remaining five species intranidal mating of the sexuals and thus continuous inbreeding is observed; the females shed their wings in the nest and disperse on foot. The inbreeding species are very closely interrelated, as was recently demonstrated with hybridization experiments. The reduction of slave‐making and the evolution of intranidal mating in this group can hardly be explained assuming ordinary models of speciation and spreading of species. I therefore suggest the scenario of an original, widespread, polytypic species with partially isolated, host‐specific races and populations in which genetic dispositions for a reduction of worker numbers and slave‐raiding, and for intranidal mating, were adaptive; the latter, however, encountered problems associated with inbreeding. Such a situation then selected for a sex‐determination mechanism resistant to inbreeding which spread throughout the range of the species, completing the life‐pattern. Due to intranidal mating and inbreeding, however, gene flow between populations is interrupted. The inbreeding system has evidently led to the conservation of a status quo in each population it has reached. The original host‐specific races are morphologically and biologically discrete entities, which should be maintained as species, as they were described, even though they consist of reproductively isolated demes which themselves are built up of isolated, clone‐like lineages.