bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction effects of fish, nutrients, mixing and sediments on autotrophic picoplankton and algal composition
Authors: Rhew Kyeongsik , Ochs Robert M. Baca Article nO.:clifford A. , Threlkeld Stephen T. 
Published: December 2004

1. We examined the effects of nutrients, turbulent mixing, mosquitofish, Gambusia affinis Baird and Girard and sediments on algal composition, algal biomass and autotrophic picoplankton (APP) abundance in a 6‐week experiment of factorial design in twenty‐four 5‐m3 outdoor mesocosms during late autumn 1995.2. Turbulent mixing decreased surface temperature and increased turbidity, which also was increased by the addition of sediments. Total algal biomass was significantly enhanced by nutrients and mixing, and decreased by the sediment treatment. In the mixing × nutrient treatment, algal biomass increased more than expected from the individual effects, while the fish × mixing and mixing × sediment treatments increased algal biomass less than expected.3. Cryptomonas (cryptomonad) blooms were observed in the unmixed, high nutrient treatment; Synedra (diatom) blooms were observed in the high nutrient, high sediment treatment; Ulothrix (green algae) blooms were observed in the mixed, high nutrient, low sediment treatment.4. Eukaryotic APP abundances were increased by sediment addition and by turbulent mixing, and increased synergistically by mixing × sediment and mixing × nutrient interactions. Prokaryotic APP abundances were decreased by nutrient enhancement and by a mixing × nutrient interaction. There were no main effects of fish on APP abundance, but fish were involved in some of the two–way interactions.5. The large number of significant interaction effects indicates that APP and other phytoplankton are regulated by a complex set of interdependent factors which should be considered simultaneously in studies of phytoplankton population dynamics and community composition.
Integrated geophysics for mineral exploration in drift‐covered volcanic terrains: examples from northern Vancouver Island, Canada
Authors: Lowe C. , Best M.E. , Bobrowsky P.T. , Seemann D.A. 
Published: December 2004

Known mineral occurrences in northern Vancouver Island are typically hosted in volcanic units of the Bonanza Group. At a local scale, the mineralization is associated with advanced argillic bedrock alteration and is often intimately related to porphyry intrusions. On a larger scale, faults are thought to exert the most significant control on the distribution of mineralized host rocks. Poor exposures and a complex glacial history limit the use of traditional methods of geological mapping and mineral exploration in this region and to date geophysical methods have been under‐utilized. Here we present findings from four standard geophysical (gravity, magnetics, electromagnetics and seismic refraction) methods, recently deployed here to elucidate the subsurface geology, as well as to identify new targets for base metal exploration.Results at two different sites show that the integrated interpretation of geophysical data, constrained by physical rock property measurements, yields detailed images of the subsurface at a fraction of the cost of drilling. At one site, east of Rupert Inlet, the final subsurface model shows that the Bonanza Group is not nearly as extensive as previously presumed. An extension of the Holberg Fault is identified some 50 km east of the visibly mapped outcrop and an extensive zone of alteration around the fault is recognized. Furthermore, a number of the methods provide support for the existence of a porphyry dike at this site. At the second site, north of Rupert Inlet, magnetic and electromagnetic data prove effective at mapping alteration and locating shear zones beneath a relatively thin drift cover. Together, these results help outline a strategy for exploration in drift‐covered terrains and show that a redirection of exploration effort is warranted in the case of northern Vancouver Island.
Selective defoliation by sheep according to slope and plant species in the hill country of New Zealand
Authors: López I. F. , Hodgson J. , Hedderley D. I. , Valentine I. , Lambert M. G. 
Published: December 2004

AbstractThe objective of the study was to evaluate the grazing behaviour by sheep in hill country paddocks in New Zealand which had received two long‐term fertilization and stocking rate treatments [high fertility–high stocking rate (HH); low fertility–low stocking rate (LL)]. Herbage accumulation and selective grazing were evaluated within low slope (LS), medium slope (MS) and high slope (HS) categories. Transects lines were placed and tillers of Agrostis capillaris and Lolium perenne in the LS category; A. capillaris, Anthoxanthum odoratum and L. perenne in the MS category; and A. capillaris and A. odoratum in the HS category were marked. The leaf length of each marked tiller was measured and used to determine selective grazing over 3 weeks during each season. The highest herbage accumulation rates were during spring and the lowest in summer and winter. The LS category showed the highest herbage accumulation rates and HS the lowest. Except for autumn, the marked tillers were more frequently grazed in the HH than in the LL paddock. During summer, autumn and spring, grazing frequency in the slope categories was in the order LS > MS > HS. During winter sheep did not discriminate between slope category. During summer, autumn and spring, sheep did not selectively graze the species studied but this was not the case during winter. Overall, sheep selectively grazed L. perenne. In all the seasons L. perenne consistently had the longest leaves but within species there was no consistent relationship between leaf length and probability of being grazed. Selective grazing changed through the year according to herbage accumulation rate. Sheep concentrated grazing in the category LS when herbage accumulation rate was high, but they did not discriminate between slope categories in winter when herbage accumulation rate was low.
Induction of nitric oxide release from the human alveolar epithelial cell line A549: an in vitro correlate of innate immune response to Mycobacterium tuberculosis
Authors: Roy Sugata , Sharma Sadhna , Sharma Monika , Aggarwal Ramesh , Bose Mridula 
Published: December 2004

SummaryIn view of the presence of a large number of epithelial cells in the alveoli of the lung and their ability to produce various cytokines and chemokines, the possible role of alveolar epithelial cells in the innate immune response to tuberculosis was examined. The human alveolar epithelial cell line A549 was used as a model. The ability of A549 cells to induce nitric oxide (NO) in response to Mycobacterium tuberculosis infection was taken as an in vitro correlate of innate immunity. M. tuberculosis infection induced A549 cells to produce significant levels of NO and to express inducible nitric oxide synthase mRNA at 48 hr of infection. However, the amount of NO released at this point was not mycobactericidal. Cytokine stimulation (interferon‐γ, tumour necrosis factor‐α, interleukin‐1β, alone or in combination) of the infected A549 cells induced a higher concentration of NO. The study of colony‐forming units (CFU) as a measure of the mycobactericidal capacity of A549 cells revealed a reduction in CFU of M. tuberculosis by 39·29% (from 10·62 ± 0·48 – 6·392 ± 0·54) following cytokine stimulation of the infected cells. Interestingly γ‐irradiated M. tuberculosis H37Rv could also induce higher than basal level of NO. Therefore we examined mycobacterial antigenic components for their possible role in NO production. We observed that A549 cells produced significantly higher amounts of NO at 48 hr when treated with mycobacterial whole cell lysates, cell wall or cell membrane preparations. The release of NO and the resultant mycobactericidal activity could be further enhanced by simultaneously conditioning the M. tuberculosis infected A549 cells with cytokine and mycobacterial components. These results suggest that alveolar epithelial cells respond to their microenvironment, which is constituted of various cytokines and macrophage‐processed antigens and may contribute to the innate immune response to tuberculosis.
Dutch consensus on diagnosis and treatment of hearing impairment in children and adults with intellectual disability
Authors: Evenhuis H. M. ,   Consensus Committee
Published: December 2004

AbstractThis is an abridged transiation of a recent Dutch consensus on diagnosis and treatment of hearing impairment in children and adults with intellectual disability. Available diagnostic methods are discussed. Tbe use of Oto‐Acoustic Emissions as a rapid and low‐cost objective screening method is particularly encouraged. Risk groups, protocols for early identification and diagnostic screening in older children and adults, recommendations for treatment and support, and priorities for research have been formulated.
A comparison of the effects of four therapy procedures on concentration and responsiveness in people with profound learning disabilities
Authors: Lindsay W. R. , Pitcaithly D. , Geelen N. , Buntin L. , Broxholme S. , Ashby M. 
Published: December 2004

AbstractThis paper is an investigation into the efficacy of four therapeutic treatment procedures increasingly used with people with profound learning disabilities: snoezelen, hand massage/aromatherapy, relaxation, and active therapy (a bouncy castle). In particular, the effects of these procedures on concentration and responsiveness were examined. Eight subjects with profound learning disabilities took part in the study and each subject received each of the treatments. To assess the effects of the treatments, simple concentration tasks were administered and the subjects' responsiveness to each treatment was rated by independent observers. The results suggest that both snoezelen and relaxation had a positive effect on concentration and seemed to be the most enjoyable therapies for clients, whereas hand massage/aromatherapy and active therapy had no or even negative effects on concentration and appeared less enjoyable.
Acquired cutis laxa associated with cutaneous angiocentric T‐cell lymphoma
Authors: Chartier Suzanne , Faucher Lise , Tousignant Jacqueline , Rochette Linda 
Published: December 2004

A 64‐year‐old man presenting with adenomegaly was diagnosed with stage IV A angiocentric cutaneous T‐cell lymphoma in 1988. Since he showed a poor response to psoralen plus UVA (PUVA) after 1 year of therapy, he was switched to systemic chemotherapy (COP), and was considered to be in remission after completion of 5 months of this regimen. In December 1989, the patient noted an asymptomatic lesion at the superior and internal aspect of his right thigh; on examination, there was a poorly circumscribed, noninflammatory, whitish, atrophic macula near the inguinal fold and a palpable adenopathy; its surface was irregular, showing small wrinkling, and could be depressed on palpation. There were no preceding inflammatory lesions and no cutaneous lymphoma lesions at this site. Slowly, the initial macule extended, and new similar lesions insidiously appeared symmetrically on the left thigh. In October 1990, the patient received electron beam therapy for a relapse that presented as troncular nodules and responded well to this therapy. In the months that followed, the skin of his whole body became progressively sagging and pendulous, without recoil. This was not preceded by an inflammatory phase or eruption. There was no family history of elastolytic disorder, and the patient was not taking any medication other than that described above. On questioning, there were no symptoms suggesting systemic involvement of this elastolytic disorder. On physical examination, the patient's whole body skin seemed redundant, nonresllient, and wrinkled, this being most obvious in the axillae, inguinal region, antecubital fossa, neck, and trunk, where loose and pendulous skin folds could be seen (Fig. 1). Also, the patient's face was excessively wrinkled and sagging and he had bilateral ectropion. At the superior and internal aspect of both thighs, large, poorly circumsoribed, but distinct, round patches of 1‐5 cm in diameter were observed; they were atrophic and whitish, with an uneven surface, and could be depressed on palpation. Apart from 1 cm, mobile, but firm, axillary and inguinal adenopathy and three subcutaneous nodules on the arm and trunk, the rest of the physical examination was unremarkable.Routine blood tests were normal, as was a chest X‐ray. Sezary cells were absent on blood smear, and borrelia and syphilis serology were negative. Thyroid function tests, angiotensin converting enzyme, and immunoelectrophoresis were within normal limits, and antinuclear antigen was negative. Two cutaneous biopsies were performed: one in an atrophic herniating lesion of the right thigh and the one on the abdomen. Both showed, on hematoxylin‐phloxin‐safran staining, a mild dermal perivascular inflammatory infiltrate with a predominance of mononuclear cells. On Weigert staining, both were marked by a net reduction in elastic fibers throughout the dermis.
Tungiasis in New York
Authors: Mashek Helen , Licznerski Barbara , Pincus Stephanie 
Published: December 2004

A 33‐year‐old African woman was evaluated for tender nodules on her feet. Accompanied by her four children, she had recently immigrated from Somalia. Before her immigration, she resided in a Kenyan refugee camp for approximately 1 year, where she walked barefoot in sand and dirt. The patient stated that she and her four children, as well as many people living in the same compound, had similar, tender lesions on their feet. Her children were “treated” by their grandmother, who removed the contents of their lesions with a safety pin.On physical examination the patient had numerous tender, isolated, and clustered hyperkeratotic, crusted papules, measuring 4–6 mm, on the plantar and periungual surfaces. Several lesions were ulcerated (Figs 1 and 2). The hyperkeratotic masses were debrided with a surgical blade. An intact, white, coiled structure was curetted from each papule, leaving numerous empty crater‐like lesions (Fig. 3), which were identified on histologic sections as Tunga penetrans. Microscopic examination of unstained specimens showed branching, thin, translucent tubular structures with numerous eggs. Ring‐shaped cross‐sections of the organism's respiratory and digestive tracts were seen on hematoxylin and eosin stain (Fig. 4).The patient received a 10‐day course of dicloxacillin and topical bacitracin ointment. All lesions were healed within 1 week of therapy.
Perspectives on colorectal cancer screening: a focus group study
Authors: Goel Vivek , Gray Ross , Chart Pam , Fitch Marg , Saibil Fred , Zdanowicz Yola 
Published: December 2004

AbstractObjective  To assess attitudes and acceptability of Ontario consumers and doctors towards colorectal screening with faecal occult blood testing (FOBT) and colonoscopy.Design, setting and participants  Focus groups with gender‐specific samples of the population, high‐risk gastroenterology patients and family doctors.Method  Semi‐structured interview guides used by facilitator to lead groups through knowledge of risk factors and prevention of colorectal cancer, the screening modalities, requirements for implementing screening programmes, barriers to screening and preferences towards screening.Main findings  There were low levels of knowledge about colorectal cancer and its prevention in the general population. FOBT was an acceptable screening modality, but considerable education about its use and benefits would be necessary to implement a screening programme. Colonoscopy was not perceived to be a good choice for a primary screen in the general population. The high‐risk group supported use of FOBT in the general population and emphasized the need for education. The doctors were more reluctant about screening, requesting clear guidelines. They also identified the time and resources that would be required if a screening programme were initiated.Conclusion  While colorectal screening is acceptable in this sample, information and decision aids are required to enable consumers and providers to make effective decisions. Implementation of colorectal screening programmes requires substantial educational efforts for both consumers and doctors.
Estimating relative parental investment in sons versus daughters
Authors: Bull J. J. , Pease C. M. 
Published: December 2004

AbstractFisher proposed that natural selection would adjust the population sex ratio so that parental expenditure on sons equals expenditure on daughters. Thus if two daughters can be produced for every son, the Fisherian equilibrium is ⅓ sons and ⅔ daughters. The relative cost of a son versus a daughter is necessarily manifested in the trade‐off between family size and sex ratio, and we offer a method to estimate this trade‐off from data on family compositions. Simulation studies indicate that the method works well in some cases but not others. Application of the method to data on a polychaete suggests that sons are much costlier than daughters; the observed sex ratio in fact significantly favored daughters, but not to the extreme predicted by our measure of differential cost.
An evolutionary interpretation of the “motivation to oviposit”
Authors: Mangel Marc 
Published: December 2004

AbstractThe ovipositional behavior of parasitoids and other insects is often described by phrases such as “motivation to oviposit” or “ovipositional drive”. This paper shows how an evolutionary (i.e. functional) interpretation can be given to such phrases. A detailed model for the parasitisation of Sycamore aphids by M. pseudoplatani is developed, using experiments by Collins and Dixon (1986). Two models are developed: i) one in which egg complement is the only state variable and ii) one in which egg complement and information concerning host densities are state variables. Comparisons of the behaviour of simulated parasitoids, using the decisions associated with the models, and the experiments suggest that both egg complement and information are important for the parasitoid's decision making. Accepting previously parasitized hosts may be optimal, and not simply an error in parasitoid perception. A number of other detailed predictions are made, such as the relative fitness of first and second eggs in superparasitized hosts and the nature of the memory of the parasitoid.
Does runaway sexual selection work in finite populations?
Authors: Nichols Richard A. , Butlin Roger K. 
Published: December 2004

AbstractFisher's runaway process is an explanation for the origin of conspicuous features which make one sex more attractive to the other. It has been suggested that it could lead to the evolution of sexual characters that significantly impair viability. Runaway selection requires a genetic correlation between alleles affecting the sexual character and alleles affecting the preference. Correlations may be expected because of assortative mating when there is variation in both the sexual character and sexual preferences. We contend that such genetic correlations are unlikely to persist in finite populations. We present simulations which confirm our expectations. They suggest that assortative mating is inefficient at generating correlations, especially if sexual selection maintains characters away from their viability optimum. In finite populations, such weak correlations will be overwhelmed by drift.
Esterase‐6 and the pheromonal effects of cis‐vaccenyl acetate in Drosophila melanogaster
Authors: Costa Rodolfo 
Published: December 2004

AbstractIn Drosophila melanogaster the polymorphic enzyme Est‐6 and a male specific lipid, cis‐vaccenyl acetate (cVA), are components of the seminal fluid. It has been suggested that cVA could be a physiological substrate for Est‐6, constituting, together with the hypothetical hydrolytic product, cis‐vaccenyl alcohol (cVOH), a pheromonal system active in the regulation of the sexual attractiveness of mated females. However, some doubt exists concerning the physiological conversion of cVA to cVOH in females. Est‐6 is also known to affect sperm motility, sperm use and female fecundity.The results of a study on qualitative and quantitative effects of topical treatment of females with cis‐vaccenyl acetate and cis‐vaccenyl alcohol on courtship behaviour are presented. The inhibition of courtship produced by cVOH was more persistent; this was possibly related to its lower volatility. The hypothesis was tested that different Est‐6 allozymes could produce different amounts of cis‐vaccenyl alcohol in vivo by differential hydrolysis of cis‐vaccenyl acetate, and thus affect the timing of remating. For this purpose highly homogeneous Est‐6S and Est‐6F homozygous lines, with almost certainly identical levels of Est‐6 and cVA, were used. They were obtained after 100 generations of inbreeding and selection of the heterozygotes at each generation. The Est‐6S and Est‐6F products of the Est‐6 structural gene did not differentially affect the timing of remating. This could imply that the two allozymes have similar catalytic properties. However, such results could be obtained even if cVA is not converted to cVOH in vivo by Est‐6.The effects of Est‐6 allozymes on sperm use after remating were also investigated. The general effect of second males was a very high elimination of first male fertilizations. No evidence for a different contribution of the two allozymes to the fitness through sperm predominance was obtained. Remating and sperm predominance experiments were performed at three temperatures: 18, 25 and 30° C. A more general—not species specific—role of cis‐vaccenyl esters is suggested by preliminary results on their presence in the ejaculate of other Drosophila species.
Karyotype evolution: Evidence from the common shrew (Sorex araneus L.)
Authors: Bengtsson Bengt O. , Frykman Ingrid 
Published: December 2004

AbstractThe common shrew is an exceptionally variable animal with respect to its chromosomes. We here review the evidence from the species concerning general questions of karyotype evolution.It appears as if chromosomal heterozygotes always are at a fitness disadvantage and that there is no exceptional amount of inbreeding that may alleviate this heterozygous effect. No other factor has been found that convincingly explain the spread of new chromosomal types and the great karyotypic variability in the species.The species is split into a number of races with incompatible karyotypes. Studies of the hybrid zones between such karyotypic races show that gene flow goes through the chromosomal barrier despite the fact that the chromosomal hybrid zones are very sharp.It has also been shown that secondary evolutionary processes in the hybrid zones tend to decrease the genetic isolation between the races involved. There is, thus, no evidence from the common shrew which indicates that simple chromosome mutations play a special role in speciation.
Morphological asymmetry and interspecific hybridization: A case study using hylid frogs
Authors: Lamb Trip , Novak James M. , Mahoney Diane L. 
Published: December 2004

AbstractThe limited studies addressing developmental stability of interspecific hybrids suggest a positive association between the level of fluctuating asymmetry and 1) the degree of divergence between parental species, and 2) the recency of the contact zone. To evaluate these associations, we examined asymmetry in a recently‐established hybrid population of treefrogs (Hyla cinerea and H. gratiosa) that show marked structural gene divergence. Fluctuating asymmetry (FA), directional asymmetry, and antisymmetry were assessed for eight paired osteometric traits in allozymically‐defined parental and hybrid categories. FA levels varied considerably among traits. Nonetheless, for any given trait, the hybrid categories did not demonstrate elevated levels of FA compared to the parental categories, or compared to frogs from a non‐hybridizing parental population. The only trait that differed statistically among categories (pterygoid length) involved a significantly lower FA value for the F1 hybrids. Thus, observed FA values do not support expectations that the hybrid categories should experience decreased developmental stability.