bluuebunny/crossref_metadata_2025 huggingface dataset:
Observatories, think tanks, and community models in the hydrologic and environmental sciences: How does it affect me?
Authors: Torgersen Thomas
Published: June 2006

Multiple issues in hydrologic and environmental sciences are now squarely in the public focus and require both government and scientific study. Two facts also emerge: (1) The new approach being touted publicly for advancing the hydrologic and environmental sciences is the establishment of community‐operated “big science” (observatories, think tanks, community models, and data repositories). (2) There have been important changes in the business of science over the last 20 years that make it important for the hydrologic and environmental sciences to demonstrate the “value” of public investment in hydrological and environmental science. Given that community‐operated big science (observatories, think tanks, community models, and data repositories) could become operational, I argue that such big science should not mean a reduction in the importance of single‐investigator science. Rather, specific linkages between the large‐scale, team‐built, community‐operated big science and the single investigator should provide context data, observatory data, and systems models for a continuing stream of hypotheses by discipline‐based, specialized research and a strong rationale for continued, single‐PI (“discovery‐based”) research. I also argue that big science can be managed to provide a better means of demonstrating the value of public investment in the hydrologic and environmental sciences. Decisions regarding policy will still be political, but big science could provide an integration of the best scientific understanding as a guide for the best policy.
Beaver dams and overbank floods influence groundwater–surface water interactions of a Rocky Mountain riparian area
Authors: Westbrook Cherie J. , Cooper David J. , Baker Bruce W.
Published: June 2006

Overbank flooding is recognized by hydrologists as a key process that drives hydrogeomorphic and ecological dynamics in mountain valleys. Beaver create dams that some ecologists have assumed may also drive riparian hydrologic processes, but empirical evidence is lacking. We examined the influence of two in‐channel beaver dams and a 10 year flood event on surface inundation, groundwater levels, and flow patterns in a broad alluvial valley during the summers of 2002–2005. We studied a 1.5 km reach of the fourth‐order Colorado River in Rocky Mountain National Park (RMNP), Colorado, USA. The beaver dams and ponds greatly enhanced the depth, extent, and duration of inundation associated with floods; they also elevate the water table during both high and low flows. Unlike previous studies we found the main effects of beaver on hydrologic processes occurred downstream of the dam rather than being confined to the near‐pond area. Beaver dams on the Colorado River caused river water to move around them as surface runoff and groundwater seepage during both high‐ and low‐flow periods. The beaver dams attenuated the expected water table decline in the drier summer months for 9 and 12 ha of the 58 ha study area. Thus we provide empirical evidence that beaver can influence hydrologic processes during the peak flow and low‐flow periods on some streams, suggesting that beaver can create and maintain hydrologic regimes suitable for the formation and persistence of wetlands.
Complete nucleotide sequence of the chlorarachniophyte nucleomorph: Nature’s smallest nucleus
Authors: Gilson Paul R. , Su Vanessa , Slamovits Claudio H. , Reith Michael E. , Keeling Patrick J. , McFadden Geoffrey I.
Published: June 2006

The introduction of plastids into different heterotrophic protists created lineages of algae that diversified explosively, proliferated in marine and freshwater environments, and radically altered the biosphere. The origins of these secondary plastids are usually inferred from the presence of additional plastid membranes. However, two examples provide unique snapshots of secondary-endosymbiosis-in-action, because they retain a vestige of the endosymbiont nucleus known as the nucleomorph. These are chlorarachniophytes and cryptomonads, which acquired their plastids from a green and red alga respectively. To allow comparisons between them, we have sequenced the nucleomorph genome from the chlorarachniophyte
Bigelowiella natans
: at a mere 373,000 bp and with only 331 genes, the smallest nuclear genome known and a model for extreme reduction. The genome is eukaryotic in nature, with three linear chromosomes containing densely packed genes with numerous overlaps. The genome is replete with 852 introns, but these are the smallest introns known, being only 18, 19, 20, or 21 nt in length. These pygmy introns are shown to be miniaturized versions of normal-sized introns present in the endosymbiont at the time of capture. Seventeen nucleomorph genes encode proteins that function in the plastid. The other nucleomorph genes are housekeeping entities, presumably underpinning maintenance and expression of these plastid proteins. Chlorarachniophyte plastids are thus serviced by three different genomes (plastid, nucleomorph, and host nucleus) requiring remarkable coordination and targeting. Although originating by two independent endosymbioses, chlorarachniophyte and cryptomonad nucleomorph genomes have converged upon remarkably similar architectures but differ in many molecular details that reflect two distinct trajectories to hypercompaction and reduction.
Complex Causal Relations and Case Study Methods: The Example of Path Dependence
Authors: Bennett Andrew , Elman Colin
Published: June 2006

This article discusses the application of qualitative methods in analyzing causal complexity. In particular, the essay reviews how process tracing and systematic case comparisons can address path-dependent explanations. The article unpacks the concept of path dependence and its component elements of causal possibility, contingency, closure of alternatives, and constraints to the current path. The article then reviews four strengths that case studies bring to the study of path dependence: offering a detailed and holistic analysis of sequences in historical cases, being suitable for the study of rare events, facilitating the search for omitted variables that might lie behind contingent events, and allowing for the study of interaction effects within one or a few cases.
The role of membrane-like stresses in determining the stability and sensitivity of the Antarctic ice sheets: back pressure and grounding line motion
Authors: Hindmarsh Richard C.A
Published: June 2006

Membrane stresses act along thin bodies which are relatively well lubricated on both surfaces. They operate in ice sheets because the bottom is either sliding, or is much less viscous than the top owing to stress and heat softening of the basal ice. Ice streams flow over very well lubricated beds, and are restrained at their sides. The ideal of the perfectly slippery bed is considered in this paper, and the propagation of mechanical effects along an ice stream considered by applying spatially varying horizontal body forces. Propagation distances depend sensitively on the rheological index, and can be very large for ice-type rheologies.

A new analytical solution for ice-shelf profiles and grounded tractionless stream profiles is presented, which show blow up of the profile in a finite distance upstream at locations where the flux is non-zero. This is a feature of an earlier analytical solution for a floating shelf.

The length scale of decay of membrane stresses from the grounding line is investigated through scale analysis. In ice sheets, such effects decay over distances of several tens of kilometres, creating a vertical boundary layer between sheet flow and shelf flow, where membrane stresses adjust. Bounded, physically reasonable steady surface profiles only exist conditionally in this boundary layer. Where bounded steady profiles exist, adjacent profile equilibria for the whole ice sheet corresponding to different grounded areas occur (neutral equilibrium). If no solution in the boundary layer can exist, the ice-sheet profile must change.

The conditions for existence can be written in terms of whether the basal rate factor (sliding or internal deformation) is too large to permit a steady solution. The critical value depends extremely sensitively on ice velocity and the back stress applied at the grounding line. High ice velocity and high stress both favour the existence of solutions and stability. Changes in these parameters can cause the steady solution existence criterion to be traversed, and the ice-sheet dynamics to change.

A finite difference model which represents both neutral equilibrium and the dynamical transition is presented, and preliminary investigations into its numerical sensitivity are carried out. Evidence for the existence of a long wavelength instability is presented through the solution of a numerical eigenproblem, which will hamper predictability.
Perceptions of variation and change in German and Swedish address1
Authors: Clyne Michael , Kretzenbacher Heinz‐Leo , Norrby Catrin , Schüpbach Doris
Published: June 2006

German and Swedish speakers diverge in contemporary address practice. The Swedish T form has become unmarked, with V limited to very specific situations. Apart from some specific T or V contexts, German now has coexistent systems, one with T, the other with V as the unmarked form, with different speakers or networks preferring one or the other. In an ongoing project, focus groups and participant observation in Austria, (eastern and western) Germany and Sweden and with Swedish speakers in Finland have identified factors and contexts determining degree of social distance and hence address choice. First name use is more marked than T use in Swedish but the two are closely linked in German. National variation is more substantial in Swedish than in German. In both languages there is some reversal of liberalization and distaste for imposition of the address form.
The semiotics of language ideologies in Singapore1
Authors: Wee Lionel
Published: June 2006

As an ethnically and linguistically diverse society, Singapore has had to grapple with the problem of how to manage this diversity across a range of contexts, thus making it a particularly interesting case study for language ideologies. This paper examines three particular cases taken from the history of Singapore's language policy. In the first situation, the policy remains largely unchanged, varying only in its lexical and textual realizations; in the second, performances in the service of a set of ideologies give rise to potentially serious problems; and in the third, the material consequences of implementing the ideologies lead to changes in the ideologies themselves. By drawing on recent theoretical developments in the study of language ideologies, this paper shows how attention to the sitedness of language ideologies can help provide greater specification and appreciation of the interactional processes by which the ideologies are instantiated.
Temperature and substrate controls on intra‐annual variation in ecosystem respiration in two subarctic vegetation types
Authors: Grogan Paul , Jonasson Sven
Published: June 2006

Arctic ecosystems are important in the context of climate change because they are expected to undergo the most rapid temperature increases, and could provide a globally significant release of CO2 to the atmosphere from their extensive bulk soil organic carbon reserves. Understanding the relative contributions of bulk soil organic matter and plant‐associated carbon pools to ecosystem respiration is critical to predicting the response of arctic ecosystem net carbon balance to climate change. In this study, we determined the variation in ecosystem respiration rates from birch forest understory and heath tundra vegetation types in northern Sweden through a full annual cycle. We used a plant biomass removal treatment to differentiate bulk soil organic matter respiration from total ecosystem respiration in each vegetation type.

Plant‐associated and bulk soil organic matter carbon pools each contributed significantly to ecosystem respiration during most phases of winter and summer in the two vegetation types. Ecosystem respiration rates through the year did not differ significantly between vegetation types despite substantial differences in biomass pools, soil depth and temperature regime. Most (76–92%) of the intra‐annual variation in ecosystem respiration rates from these two common mesic subarctic ecosystems was explained using a first‐order exponential equation relating respiration to substrate chemical quality and soil temperature. Removal of plants and their current year's litter significantly reduced the sensitivity of ecosystem respiration to intra‐annual variations in soil temperature for both vegetation types, indicating that respiration derived from recent plant carbon fixation was more temperature sensitive than respiration from bulk soil organic matter carbon stores.

Accurate assessment of the potential for positive feedbacks from high‐latitude ecosystems to CO2‐induced climate change will require the development of ecosystem‐level physiological models of net carbon exchange that differentiate the responses of major C pools, that account for effects of vegetation type, and that integrate over summer and winter seasons.
Net ecosystem production of a Douglas‐fir stand for 3 years following clearcut harvesting
Authors: Humphreys Elyn R. , Andrew Black T. , Morgenstern Kai , Li Zhong , Nesic Zoran
Published: June 2006

To investigate the variations in annual and seasonal net ecosystem production (FNEP) during the development of a young forest, 3 years of continuous eddy covariance measurements of carbon dioxide (CO2) fluxes were collected following clearcut harvesting and replanting of a coastal Douglas‐fir stand on the east coast of Vancouver Island, BC, Canada. The impact of changing weather and stand structure onFNEPwas examined by developing relationships betweenFNEPand variables such as light, temperature, soil moisture, and leaf area index (LAI). In all 3 years, the stand was a large source of CO2(620, 520, and 600 g C m−2 yr−1in the first, second, and third years, respectively). During this period, the growth of pioneer and understory species resulted in an increase in maximum growing season LAI from 0.2 in the year the seedlings were planted to 2.5 in the third year. The associated increase in annual gross ecosystem production (P=FNEP−Re, whereReis ecosystem respiration) from 220 g C m−2 yr−1in the first year to 640 g C m−2 yr−1in the third year was exceeded by an increase in annualRefrom 840 to 1240 g C m−2 yr−1. Seasonal and interannual variations in daytimeFNEPandPwere well described by variations in photosynthetically active radiation, temperature, and changes in LAI. Night‐time measurements ofReexponentially increased with 2 cm soil temperature with an averageQ10of 2 (relative increase inRefor a 10°C increase in temperature) andR10(Reat 10°C) that increased from 2.1 in the first year to 2.5 in the second year to 3.2 μmol m−2 s−1in the third year. Although the re‐establishment of vegetation in this stand had a major impact on bothPandRe, interannual variations in weather also affected annualFNEP. Drought, in the summer of the third year, resulted in early senescence and reduced bothPandRe. This resulted in more C being lost from the stand in the third year after harvesting than in the second year.
Global change alters the stability of food webs
Authors: Emmerson Mark , Bezemer Martijn , Hunter Mark D. , Jones T. Hefin
Published: June 2006

Recent research has generally shown that a small change in the number of species in a food web can have consequences both for community structure and ecosystem processes. However ‘change’ is not limited to just the number of species in a community, but might include an alteration to such properties as precipitation, nutrient cycling and temperature. How such changes might affect species interactions is important, not just through the presence or absence of interactions, but also because the patterning of interaction strengths among species is intimately associated with community stability. Interaction strengths encompass such properties as feeding rates and assimilation efficiencies, and encapsulate functionally important information with regard to ecosystem processes. Interaction strengths represent the pathways and transfer of energy through an ecosystem. We review the best empirical data available detailing the frequency distribution of interaction strengths in communities. We present the underlying (but consistent) pattern of species interactions and discuss the implications of this patterning. We then examine how such a basic pattern might be affected given various scenarios of ‘change’ and discuss the consequences for community stability and ecosystem functioning.
Macroscopic prey remains in the winter diet of foxes Vulpes vulpes in rural Britain
Authors: WEBBON CHARLOTTE C. , BAKER PHILIP J. , COLE NIK C. , HARRIS STEPHEN
Published: June 2006

The winter diet of foxes Vulpes vulpes was quantified in seven landscape types in Britain, using faecal samples from 87 sites.

Medium‐sized mammals (0.1–5.0 kg) were consistently the most important prey group in arable and pastural landscapes, occurring in 44–72% of scats and comprising 50–75% of the mass of prey ingested. Birds and small mammals (< 0.1 kg) were important secondary prey groups.

Small mammals were the most frequently recorded prey group in marginal upland (42% of scats) and upland landscapes (75%), followed by large mammals (33% and 23%, respectively). In terms of mass ingested, small mammals (38%) and large mammals (52%) were the most important prey groups in these landscapes.

In all landscapes, field voles Microtus agrestis, lagomorphs, sheep/deer and passerines/galliforms dominated their respective prey groupings.
Ecological effects and distribution of invasive non‐native mammals on the Canary Islands
Authors: NOGALES M. , RODRÍGUEZ‐LUENGO J. L. , MARRERO P.
Published: June 2006

The ecological effects and distribution of 13 invasive non‐native mammal species on the Canary Islands are reviewed.

Six species, representing six different taxonomic orders, are widely distributed and live on all seven main islands of the Canarian Archipelago: Felis catus, Capra hircus, Rattus rattus, Rattus norvegicus, Mus domesticus and Oryctolagus cuniculus. Atelerix algirus is found on four islands while six further species are present on only one island: Crocidura russula, Suncus etruscus, Rousettus egyptiacus, Ovis gmelini, Ammotragus lervia and Atlantoxerus getulus.

Five species have an omnivorous diet, four are herbivorous, two insectivorous, one frugivorous and one carnivorous. The ecological effects and damage caused by these species in the natural habitats of the Canaries are similar to those in other insular regions. To our knowledge, the effects of two species, A. lervia (herbivorous) and A. getulus (omnivorous), are as yet unreported for other insular environments.

Two of the most pernicious effects caused by invasive non‐native mammal species in the Canaries consist of predation by feral cats of the three giant lizard species present in the western islands, but especially Gallotia gomerana, which is now on the verge of extinction; and the damage that the four species of herbivores cause to the endemic flora of the archipelago.
Characteristics of unmatched maternal and baby records in linked birth records and hospital discharge data
Authors: Ford Jane B. , Roberts Christine L. , Taylor Lee K.
Published: June 2006

Linkage of routinely collected health data collections is increasingly being used to investigate maternal and infant morbidity and mortality. Such data have the advantage of being population based and readily available. However, in using such data it is important to understand the data linkage process, the proportions of unmatched records and the characteristics of these records so that potential bias can be recognised. This article describes the differences in characteristics of matched and unmatched mothers’ and babies’ records generated in the linkage of birth records with hospital discharge data and explores some of the reasons for these differences. The study population included over 250 000 women and their babies discharged from hospital following delivery in New South Wales, Australia between 1 January 2000 and 31 December 2002.

Hospital discharge and birth data were linked using probabilistic linkage methods for both mothers and babies. Matching rates were 98.5% and 99.0% for maternal birth and hospital discharge records, respectively, and 98.8% and 99.4% for baby records. Unmatched maternal records had higher proportions of Australian‐born women, private hospital births and stillbirths compared with matched records. Unmatched baby records had higher proportions of low‐birthweight babies, preterm births and in‐hospital deaths than matched records. With the possible exception of stillbirths, these differences are unlikely to cause important bias in studies relying on matched records only. Our results suggest studies using linked data should generally examine and report on the characteristics of unmatched records, and recognise them as a potential source of bias.
Nausea and vomiting in pregnancy: maternal characteristics and risk factors
Authors: Louik Carol , Hernandez‐Diaz Sonia , Werler Martha M. , Mitchell Allen A.
Published: June 2006

Nausea with or without vomiting (NVP) is probably the most frequently reported medical complaint of pregnancy, but few studies have considered risk factors for its development. We used data from an ongoing epidemiological study of pregnancies in four regional centres. Mothers of infants with congenital malformations (n = 17 158) and a sample of normal infants (n = 5329) were interviewed within 6 months of delivery by trained nurse‐interviewers using a standardised questionnaire. For all risk factors investigated, odds ratios and 95% confidence intervals were calculated using multiple logistic regression, controlling for potential confounders.

The cumulative incidence (risk) of NVP was 67%. The risk of NVP and its timing during pregnancy were similar for mothers of malformed and normal infants, so data were combined. No changes in the NVP risk were observed over the 20‐year study period. The risk decreased with increasing age, but increased with increasing gravidity. The risk also increased with increasing number of prior miscarriages. Further, within each gravidity category, the risk was higher for twin births than for singletons. Women who reported onset of NVP after the first trimester differed demographically from women whose NVP began earlier: they were less‐well educated, had lower incomes, and were more likely to be black.

The finding that the number of prior pregnancies, both complete and incomplete, and number of fetuses independently appear to increase the risk of NVP suggests a fetal ‘dose’ effect. Together with selected demographic characteristics that differentiate early‐ vs. late‐onset NVP, these findings warrant further investigation.
Phosphorylation and 14‐3‐3 binding of Arabidopsis trehalose‐phosphate synthase 5 in response to 2‐deoxyglucose
Authors: Harthill Jean E. , Meek Sarah E. M. , Morrice Nick , Peggie Mark W. , Borch Jonas , Wong Barry H. C. , MacKintosh Carol
Published: June 2006

Trehalose‐6‐phosphate is a ‘sugar signal’ that regulates plant metabolism and development. The Arabidopsis genome encodes trehalose‐6‐phosphate synthase (TPS) and trehalose‐6‐phosphatase (TPP) enzymes. It also encodes class II proteins (TPS isoforms 5–11) that contain both TPS‐like and TPP‐like domains, although whether these have enzymatic activity is unknown. In this paper, we show that TPS5, 6 and 7 are phosphoproteins that bind to 14‐3‐3 proteins, by using 14‐3‐3 affinity chromatography, 14‐3‐3 overlay assays, and by co‐immunoprecipitating TPS5 and 14‐3‐3 isoforms from cell extracts. GST–TPS5 bound to 14‐3‐3s after in vitro phosphorylation at Ser22 and Thr49 by either mammalian AMP‐activated protein kinase (AMPK) or partially purified plant Snf1‐related protein kinase  1 (SnRK1s). Dephosphorylation of TPS5, or mutation of either Ser22 or Thr49, abolished binding to 14‐3‐3s. Ser22 and Thr49 are both conserved in TPS5, 7, 9 and 10. When GST–TPS5 was expressed in human HEK293 cells, Thr49 was phosphorylated in response to 2‐deoxyglucose or phenformin, stimuli that activate the AMPK via the upstream kinase LKB1. 2‐deoxyglucose stimulated Thr49 phosphorylation of endogenous TPS5 in Arabidopsis cells, whereas phenformin did not. Moreover, extractable SnRK1 activity was increased in Arabidopsis cells in response to 2‐deoxyglucose. The plant kinase was inactivated by dephosphorylation and reactivated by phosphorylation with human LKB1, indicating that elements of the SnRK1/AMPK pathway are conserved in Arabidopsis and human cells. We hypothesize that coordinated phosphorylation and 14‐3‐3 binding of nitrate reductase (NR), 6‐phosphofructo‐2‐kinase/fructose‐2,6‐bisphosphatase (F2KP) and class II TPS isoforms mediate responses to signals that activate SnRK1.
Monitoring survival and function of transfused platelets in Glanzmann thrombasthenia by flow cytometry and thrombelastography
Authors: Male C. , Koren D. , Eichelberger B. , Kaufmann K. , Panzer S.
Published: June 2006

Patients with Glanzmann thrombasthenia (GT) may form isoantibodies which induce refractoriness or inhibition of function of transfused platelets. We monitored the survival and function of transfused platelets by flow cytometry and thrombelastography in a patient with GT. Gating on CD42a+ allowed identification of even a few transfused platelets. Only by gating on these CD41+ CD42a+ cells were we able to demonstrate their capability to bind fibrinogen and PAC‐1 upon activation. Platelets were rapidly cleared from the circulation as a result of boosted isoantibodies. The contribution of transfused platelets to clot formation was also demonstrated by thrombelastography by blocking their function with abciximab.
The usefulness of ureterorenoscopic examination in evaluation of upper tract disease
Authors: MATSUMOTO AKIHIRO , TOBE TOYOFUSA , KAMIJIMA SHUUICHI , ARAKI KAZUHIRO , NAYA YUKIO , IGARASHI TATSUO , ICHIKAWA TOMOHIKO
Published: June 2006

Aim:  The objective of the present study was to clarify the indications, usefulness and limitations of ureterorenoscopy.

Material and methods:  From January 1998 to June 2004, 72 consecutive patients (48 men and 24 women) with a mean age of 66 years (range, 27–83 years) underwent ureterorenoscopy to diagnose upper urinary tract tumors (UUT). Median follow‐up was 24 months (range, 1–73 months). Patients were divided into four subgroups by voided urine cytology and preoperative radiographic findings. Group A (n = 11, 15.3%), positive voided urine cytology and positive preoperative radiographic findings; group B (n = 5, 6.9%), positive cytology and negative radiographic findings; group C (n = 48, 66.7%), negative cytology and positive radiographic findings and group D (n = 8, 11.1%), frank hematuria originating from the UUT but negative cytology and negative radiographic findings. We compared the findings of ureterorenoscopic examination and biopsy with the results of retrograde pyelography and cytology of upper tract urine. For each examination, the following diagnostic indices were assessed: sensitivity, specificity, positive‐predictive‐value (PPV) and negative‐predictive‐value (NPV) and accuracy. Statistical analysis was performed using McNemar’s test.

Results:  For ureterorenoscopy, sensitivity was 94%, specificity 59%, PPV 72%, NPV 92% and accuracy 76%. For biopsy, sensitivity was 77%, specificity 100%, PPV 100%, NPV 80% and accuracy 88%. Accuracy of ureterorenoscopy tended to be superior to that of retrograde pyelography. Ureterorenoscopy was most useful in the group which consisted of 48 patients (66.7%) with negative voided urine cytology and positive preoperative radiographic findings. This group was the only group in which accuracy of ureterorenoscopic biopsy was superior to that of urine cytology, significantly (P = 0.03).

Conclusion:  Results indicated that ureterorenoscopy is most suitable and gives superior accuracy in patients with positive radiographic findings and negative voiding cytology. Ureterorenoscopic biopsy of the upper urinary tract would provide useful information when considering therapeutic strategies, such as nephron‐sparing management.
Hardness evaluation of penile prostheses
Authors: WANG SHYH‐JEN , CHEN KUANG‐KUO , LIN ALEX TONG‐LONG , YOUNG SHUENN‐TSONG , CHANG LUKE S
Published: June 2006

Aim:  This work investigates the hardness and buckling force of penile prostheses to further understand the rigidity of penile prostheses before and after implantation.

Methods:  Evaluated herein are four prosthetic samples (three inflatable, one semi‐rigid), five real prostheses (one inflatable, four semi‐rigid), and one prosthesis after implantation. The hardness is measured with a Shore Durimeter by pressing the tester’s indentor to the surface of the specimen. A volunteer with inflatable prosthesis implantation is evaluated with respect to penile hardness versus various numbers of pumping. The buckling force of the prosthesis is also determined by a push‐pull gauge and a specially designed sampling table.

Results:  Results in this study demonstrate that although the inflatable prosthesis could only be pumped to a certain amount of hardness, hardness and buckling force correlate well with each other. After reaching the hardness limit, prostheses can even be pumped a further few times. However, continuous pumping only puts more tension on the prosthetic material without increasing hardness and could induce mechanical failure of the prosthesis. Results also indicate that the buckling force decreases with increasing length of the semirigid prostheses, and increases when the prosthesis has a larger diameter.

Conclusion:  This mechanical measurement of rigidity in penile prostheses could provide more information to clinicians about the penile prosthesis before surgical implantation, and to patients about prosthesis usage after implantation.
Acute urinary retention as a result of a bladder diverticulum
Authors: ASLAM FAWAD , SYED JUNAID ALI , NADEEM NAILA , HUSSAIN SHABBIR
Published: June 2006

Abstract  An 11‐month‐old infant presented with acute urinary retention. He had presented 3 months earlier with complaints of an enlarging abdominal mass that was initially diagnosed as a mesenteric cyst on ultrasonography. Voiding cystourethrogram revealed a large bladder diverticulum. Bladder diverticulum should be a differential diagnosis in children, especially male, presenting with urinary retention, fever and an abdominal mass.
Encapsulated triamcinolone cyst after subtenon injection
Authors: Chan Carmen KM , Mohamed Shaheeda , Tang Emily WH , Shanmugam Mahesh P , Chan Nongnart R , Lam Dennis SC
Published: June 2006

Abstract

The authors report the formation of a subtenon cyst following subtenon triamcinolone injection for chronic recurrent uveitis in Behçet’s disease. The steroid was inadvertently placed superficially in the anterior subtenon space and was encapsulated eventually to present as a subtenon cyst. The episode of uveitis recurrence, which did not regress, required treatment with a repeat posterior subtenon injection 2 months later. The cyst was removed 4.5 months after the initial subtenon injection, when the patient underwent a trabeculectomy for refractory glaucoma. Histological examination of the cyst revealed a fibrous encapsulated cavity filled with small birefringent crystals, consistent with an encapsulated triamcinolone collection. Fibrous encapsulation of triamcinolone crystals can arise after a superficially placed anterior subtenon injection and this may impede the absorption of the corticosteroid and hamper its effectiveness in treating ocular inflammatory diseases.
Optical imaging of medullary ventral respiratory network during eupnea and gasping In situ
Authors: Potts Jeffrey T. , Paton Julian F. R.
Published: June 2006

In severe hypoxia, respiratory rhythm is shifted from an eupneic, ramp‐like motor pattern to gasping characterized by a decrementing pattern of phrenic motor activity. However, it is not known whether hypoxia reconfigures the spatiotemporal organization of the central respiratory rhythm generator. Using the in situ arterially perfused juvenile rat preparation, we investigated whether the shift from eupnea to gasping was associated with a reconfiguration of the spatiotemporal pattern of respiratory neuronal activity in the ventral medullary respiratory network. Optical images of medullary respiratory network activity were obtained from male rats (4–6 weeks of age). Part of the medullary network was stained with a voltage‐sensitive dye (di‐2 ANEPEQ) centred both within, and adjacent to, the pre‐Bötzinger complex (Pre‐BötC). During eupnea, optical signals initially increased prior to the onset of phrenic activity and progressively intensified during the inspiratory phase peaking at the end of inspiration. During early expiration, fluorescence was also detected and slowly declined throughout this phase. In contrast, hypoxia shifted the respiratory motor pattern from eupnea to gasping and optical signals were restricted to inspiration only. Areas active during gasping showed fluorescence that was more intensive and covered a larger region of the rostral ventrolateral medulla compared to eupnea. Regions exhibiting peak inspiratory fluorescence did not coincide spatially during eupnea and gasping. Moreover, there was a recruitment of additional medullary regions during gasping that were not active during eupnea. These results provide novel evidence that the shift in respiratory motor pattern from eupnea to gasping appears to be associated with a reconfiguration of the central respiratory rhythm generator characterized by changes in its spatiotemporal organization.
Prokaryotic diversity and metabolically active microbial populations in sediments from an active mud volcano in the Gulf of Mexico
Authors: Martinez Robert J. , Mills Heath J. , Story Sandra , Sobecky Patricia A.
Published: June 2006

In this study, ribosomes and genomic DNA were extracted from three sediment depths (0–2, 6–8 and 10–12 cm) to determine the vertical changes in the microbial community composition and identify metabolically active microbial populations in sediments obtained from an active seafloor mud volcano site in the northern Gulf of Mexico. Domain‐specific Bacteria and Archaea 16S polymerase chain reaction primers were used to amplify 16S rDNA gene sequences from extracted DNA. Complementary 16S ribosomal DNA (crDNA) was obtained from rRNA extracted from each sediment depth that had been subjected to reverse transcription polymerase chain reaction amplification. Twelve different 16S clone libraries, representing the three sediment depths, were constructed and a total of 154 rDNA (DNA‐derived) and 142 crDNA (RNA‐derived) Bacteria clones and 134 rDNA and 146 crDNA Archaea clones obtained. Analyses of the 576 clones revealed distinct differences in the composition and patterns of metabolically active microbial phylotypes relative to sediment depth. For example, ɛ‐Proteobacteria rDNA clones dominated the 0–2 cm clone library whereas γ‐Proteobacteria dominated the 0–2 cm crDNA library suggesting γ to be among the most active in situ populations detected at 0–2 cm. Some microbial lineages, although detected at a frequency as high as 9% or greater in the total DNA library (i.e. Actinobacteria, α‐Proteobacteria), were markedly absent from the RNA‐derived libraries suggesting a lack of in situ activity at any depth in the mud volcano sediments. This study is one of the first to report the composition of the microbial assemblages and physiologically active members of archaeal and bacterial populations extant in a Gulf of Mexico submarine mud volcano.
Transport of radiocaesium by arbuscular mycorrhizal fungi to Medicago truncatula under in vitro conditions
Authors: De Boulois Hervé Dupré , Voets Liesbeth , Delvaux Bruno , Jakobsen Iver , Declerck Stéphane
Published: June 2006

The capacity of arbuscular mycorrhizal (AM) fungi to take up and translocate radiocaesium (Cs) to their host has been shown using the root‐organ culture (ROC) system. However, the absence of photosynthetic tissues, lack of a normal root hormonal balance and incomplete source–sink relationships may bias the bidirectional transfer of elements at the symbiotic interface and complicate transport studies. Accordingly, we developed a novel culture system [i.e. the Arbuscular Mycorrhizal‐Plant (AM‐P) in vitro culture system], where AM fungi and an autotrophic host plant develop under strict in vitro conditions. With this system, we unambiguously demonstrated the capacity of AM fungi to transport Cs. The extraradical fungal hyphae took up 21.0% of the initial supply of 134Cs. Translocation to the plant represented 83.6% of the 134Cs taken up. Distribution of 134Cs in the host plant was 89.8% in the mycorrhizal roots and 10.2% in the shoot. These results confirm that AM fungi can take up, translocate and accumulate Cs. They further demonstrate unambiguously and for the first time that Cs can be transferred from AM fungi to host tissues. These results suggest a potential involvement of AM fungi in Cs biogeochemical cycle and in plant Cs accumulation.
Treating stage I nonseminomatous germ cell tumours with a single cycle of chemotherapy
Authors: GILBERT DUNCAN C. , NORMAN ANDREW R. , NICHOLL JUDITH , DEARNALEY DAVID P. , HORWICH ALAN , HUDDART ROBERT A.
Published: June 2006

OBJECTIVE

To estimate the rate of relapse in men with stage I nonseminomatous germ cell tumours (NSGCT) of the testis treated with one cycle of chemotherapy instead of the usual two cycles.

PATIENTS AND METHODS

Between 1992 and 1996, 22 men with stage I NSGCT who had normalized tumour markers after orchidectomy and negative findings on computed tomography, and who were at moderate risk of relapse, were treated with one cycle of platinum‐containing chemotherapy (bleomycin and etoposide with either cisplatin or carboplatin).

RESULTS

At a median follow‐up of 10.2 years, none of the patients have relapsed with malignant GCTs.

CONCLUSIONS

The results after one cycle of chemotherapy are no worse than after two cycles. The present study needs to be replicated in a larger cohort of patients to define the relapse risk more accurately. This approach is soon to be tested in a large multicentre trial randomizing patients between one and two cycles
Assessment of aberrations on chromosome 8 in prostatic atrophy
Authors: YILDIZ‐SEZER SEVAL , VERDORFER IRMGARD , SCHÄFER GEORG , ROGATSCH HERMANN , BARTSCH GEORG , MIKUZ GREGOR
Published: June 2006

OBJECTIVE

To systematically examine the genetic alterations on chromosome 8 in prostate epithelia deriving from atrophic areas, and to compare these alterations with those of cells derived from prostatic intraepithelial neoplasia (PIN) and prostate cancer in the same organ.

MATERIAL AND METHODS

Tissue microarrays were constructed from 50 patients with histologically different tissues, including normal, PIN, atrophy and cancer lesions. Control samples were obtained from 10 patients who died from causes other than prostate cancer. Multicolour DNA probes for 8p22, centromere 8 and 8q24 were used to detect genetic alterations by fluorescence in situ hybridisation analysis.

RESULTS

Chromosomal alterations were detected on chromosome 8 in all analysed tissues. Including all observed signal patterns, a gradual increase of nuclei with loss of 8p22 was detected in normal (16%), in atrophy (21%), in PIN (25%) and in cancer tissue (31%), and there was gain in 8q24 in normal tissue (10%), in atrophy lesions (19%), in PIN (21%) and in cancer (27%). Generally, in all three lesion types the percentage of cells with 8q24 gain was significantly lower than the percentage of cells with loss of 8p22.

CONCLUSION

This investigation confirms the presence of severe chromosomal aberrations in the epithelium of the atrophic glands of the prostate. The aberrations are the same those that can be found in PIN and in prostate cancer. These findings confirm the genetic instability of the cells in the atrophic areas of the prostate, which can be a target for further injuries, leading to prostate cancer.
Interstitial cells and phasic activity in the isolated mouse bladder
Authors: LAGOU MAGDALINI , DRAKE MARCUS J. , MARKERINK‐VAN ITTERSUM MARJANNE , DE VENTE JAN , GILLESPIE JAMES I.
Published: June 2006

OBJECTIVE

To describe the distribution of interstitial cells (ICs, defined as cells which show an increase in cGMP in response to nitric oxide, NO) in the isolated mouse bladder, and changes in phasic contractile activity after exposure to a NO donor.

MATERIALS AND METHODS

The whole bladder was removed from 17 female mice, killed by cervical dislocation. For immunohistochemistry (six mice) the bladder was incubated in carboxygenated Krebs’ solution at 36 °C, containing 1 mm of the phosphodiesterase inhibitor isobutyl‐methyl‐xanthine. Individual pieces of tissue were exposed to 100 µm of the NO donor diethylamine NONOate for 10 min; control tissues remained in Krebs’ solution. Tissues were then fixed in 4% paraformaldehyde and processed for cGMP immunohistochemistry. Bladder pressure was measured in bladders from 11 mice; the bladders were cannulated via the urethra and suspended in a heated chamber containing carboxygenated Tyrode solution at 33–35 °C and intravesical pressure recorded. All drugs were added to the solution bathing the abluminal surface.

RESULTS

NO induced an increase in cGMP in cells in the outer layers of the bladder wall, forming two distinct types based on their location; cells lying on the surface of the muscle bundles (surface muscle ICs) and cells within the muscle bundles (intramuscular ICs). Cholinergic nerve fibres were identified by the expression of vesicular acetylcholine transporter and neuronal NO synthase (nNOS). Choline acetyltransferase‐ and nNOS‐positive nerves also had high cGMP levels in response to 100 µm diethylamine NONOate. In vitro exposure of an isolated whole unstimulated bladder to 100 µm diethylamine NONOate had no effect on resting bladder pressure. When whole bladders were exposed to muscarinic stimulation (30–100 nm arecaidine) there was an initial large transient rise in pressure followed by complex phasic changes in pressure. Adding 100 µm diethylamine NONOate abolished this phasic activity. Interestingly, the phasic activity was inhibited midway between the peak and trough of a phasic cycle. Such a pattern of inhibition might reflect the complexity of the phasic activity involving both excitatory and inhibitory components.

CONCLUSIONS

These data show the presence of NO/cGMP‐sensitive ICs in the outer muscle layers of the mouse bladder. Activating these cells alters the pattern of muscarinic‐induced phasic activity. We suggest that the role of the ICs in the outer muscle layers is to generate and modulate phasic activity. If so, then this is the first report of a functional role for ICs in the bladder.
Can the kidney function as a lung? Systemic oxygenation and renal preservation during retrograde perfusion of the ischaemic kidney in rabbits
Authors: HUMPHREYS MITCHELL R. , ERETH MARK H. , SEBO THOMAS J. , SLEZAK JEFFREY M. , DONG YUE , BLUTE MICHAEL L. , GETTMAN MATTHEW T.
Published: June 2006

OBJECTIVE

To investigate renal preservation by a novel method of perfusion using an oxygenated perfluorocarbon (PFC) emulsion via retrograde access to the kidney, as preserving renal function during urological surgery has been elusive, and the recognized technique of nephron‐sparing surgery has increased its application and practice in modern urology.

MATERIALS AND METHODS

After institutional review and approval, 30 New Zealand White rabbits were studied. In a solitary kidney model, each rabbit had the ureter catheterized before 40 min of renal artery occlusion. Each rabbit was randomized to one retrograde perfusion group, i.e. sham, normothermic PFC, chilled PFC, normothermic saline, and chilled saline. The rabbits were maintained for 2 weeks, during which renal function, urine output, systemic blood gases, weight and serum creatinine level were measured. After death, the kidneys were individually examined and graded by one renal pathologist unaware of the treatment.

RESULTS

The rabbits treated with retrograde PFC perfusion (normothermic and chilled) had less change in their creatinine clearance, at 3.6 and 4.0 mL/min per kg, than the sham group, at 7.8 mL/min per kg, while also having significantly higher systemic venous oxygenation, at 26.3 and 10.0 mmHg, than the sham group, at 0.2 mmHg. Normothermic and chilled perfusion with PFC was also associated with less histological evidence of ischaemic damage, with mean (sd) scores of 13.0 (13.5) and 8.7 (4.5), respectively, than in the sham group, at 33.3 (16.8), while favourably matching the contralateral control kidney group, at 5.5 (2.3). The rabbits treated with saline retrograde perfusion also had better outcomes than the sham cohort. There were no adverse effects in any of the study arms or with the use of PFC.

CONCLUSION

Retrograde oxygen delivery to the kidney through the urinary collecting system was successful in this pilot study. Renal function, laboratory and histological data indicate a trend towards renal preservation and even systemic oxygenation in the experimental groups compared with the sham rabbits, with no adverse effects attributed to this technique.
Effect of pioglitazone on insulin sensitivity, vascular function and cardiovascular inflammatory markers in insulin‐resistant non‐diabetic Asian Indians
Authors: Raji A. , Gerhard‐Herman M. D. , Williams J. S. , O’Connor M. E. , Simonson D. C.
Published: June 2006

Aims  To determine the effects of pioglitazone (30 mg once daily for 16 weeks) on insulin sensitivity, insulin‐mediated vasodilation, vascular inflammatory markers, fat distribution and lipids in Asian Indians and Caucasians of European ancestry.

Methods  Cross‐sectional study. Eighteen non‐diabetic Asian Indians and 17 Caucasians of comparable age (34 ± 3 vs. 36 ± 3 years) and body mass index (26.0 ± 1.2 vs. 24.7 ± 1.0 kg/m2) had measurements of insulin sensitivity (M, insulin clamp at 6 pmol/kg per min), abdominal fat (computed tomographic scan at L4‐L5), endothelial‐dependent (reactive hyperaemia, RH) and ‐independent (0.4 mg sublingual nitroglycerin, TNG) vasodilation using brachial artery ultrasound before and after the 2‐h clamp at baseline and after pioglitazone therapy.

Results  Asian Indians were insulin resistant compared with Causasians during the baseline clamp (M = 25.6 ± 1.7 vs. 41.1 ± 2.2 µmol/kg per min, P < 0.0001) and improved significantly after pioglitazone (to 33.9 ± 1.7 µmol/kg per min, P < 0.001). Vasodilatory responses to RH and TNG were similar in Asian Indians and Caucasians at baseline and did not change. Insulin‐mediated vasodilation improved after pioglitazone in Asian Indians, but not in Caucasians, and correlated with the change in insulin sensitivity (r = 0.52, P = 0.03). C‐reactive protein (CRP) was higher in Asian Indians vs. Caucasians (1.6 ± 0.4 vs. 0.9 ± 0.2 mg/l) and was negatively correlated with insulin sensitivity (r = −0.53, P = 0.02). In the Asian Indian group, CRP and plasminogen activator inhibitor‐1 decreased and adiponectin increased after pioglitazone, but there were no significant changes in total or visceral fat.

Conclusions  These results demonstrate that insulin‐resistant Asian Indians respond favourably to an insulin sensitizer with improvements in insulin sensitivity, cardiovascular and inflammatory risk markers, and vascular responses to insulin. These agents may have a role in decreasing the risk of diabetes and cardiovascular disease in this high‐risk population.