bluuebunny/crossref_metadata_2025 huggingface dataset:
Incremental propagation of discrete compaction bands: Acoustic emission and microstructural observations on circumferentially notched samples of Bentheim
Authors: Vajdova Veronika , Wong Teng‐Fong
Published: August 2003

To simulate how compaction localization may develop from structural and stress heterogeneity, we studied in the laboratory the influence of a stress concentration due to a V‐shaped circumferential notch in a cylindrical sample of Bentheim sandstone. Conventional triaxial experiments at confining pressure of 300 MPa were conducted. Acoustic emission activity was recorded, and each sample was deformed to a different stage and subsequently retrieved for microstructural observations. Our data indicate that compaction bands initiated from the notch tips and propagated by sequential increments as “anti‐cracks”. The transverse propagation of a compaction band was inferred to be faster than the axial displacement rate by 2 orders of magnitude. Energy dissipated for compaction band formation was estimated to be comparable to the shear fracture energy for shear band propagation.
Formation of convective carbon dioxide clouds near the south pole of Mars
Authors: Colaprete Anthony , Haberle Robert M. , Toon Owen B.
Published: August 2003

Observations from the Mars Orbiter Laser Altimeter (MOLA) indicate a distinct difference in the nature of north and south polar clouds. The majority of north polar clouds are diffuse with relatively low optical extinction (channel 4 clouds). In contrast, a significant number of south polar clouds provide very strong laser echoes suggesting optical extinction as high as 300 km−1 (channel 1 clouds). These high extinction clouds were almost exclusively observed in the polar night between 70° and 85°S. We have previously shown that the low extinction clouds are composed of a small number of large carbon dioxide particles, which form in relatively gentle updrafts, or lee waves. A possible explanation for the high extinction clouds is that they are composed of more, but somewhat smaller, carbon dioxide particles forming in high‐velocity convective updrafts. Numerical simulations using a microphysical cloud model show that the cloud extinction depends most strongly on the availability of ice nuclei (IN), assumed to be dust, and the updraft velocity. Radiative cooling by the CO2 clouds can further destabilize the air column. Cloud extinction consistent with MOLA observations is produced for IN concentrations greater than 5 cm−3 and updraft core velocities of ∼2 m s−1. The discrepancy in north and south cloud extinction may be the result of differing IN concentrations and stability regimes between the north and south polar regions. Many channel 4 clouds may also be convective but formed in air with either low updraft velocities or low abundances of ice nuclei.
Nonergodic solute transport in physically and chemically heterogeneous porous media
Authors: Zhang You‐Kuan
Published: August 2003

The time‐dependent ensemble average of the first‐order longitudinal second spatial moment, 〈S11′R〉, of nonergodic plumes of a sorbing solute in linear equilibrium and the effective longitudinal dispersivity, γ11′R, were evaluated for the line sources of different lengths normal or parallel to the uniform mean velocity, μ, in two‐ and three‐dimensional physically and chemically heterogeneous and statistically isotropic media. Physical and chemical heterogeneity is described with a random hydraulic conductivity field K(x) and a random retardation factor field R(x), respectively. The retardation factor is defined as 1 + Kd(x), where Kd(x) is the distribution coefficient. The fields K(x) and Kd(x) are assumed to be lognormally distributed and correlated. Three correlation models between Y = log K and W = log Kd are considered: the perfectly positive correlation (model A), the perfectly negative correlation (model B), and no correlation (model C). The values of Z11′R, which is defined as 〈 S11′R〉 minus its initial value, and γ11′ R for all three correlation models increase as the length of a line source l increases. As l→ ∞, Z11′R or γ11′R approach their respective ergodic limits X11′R or α11′R. The asymptotic longitudinal dispersion due to the physical and chemical heterogeneity is Fickian for a line source normal to μ and non‐Fickian for a line source parallel to μ. The positive correlation between Y and W reduces Z11′R and γ11′R, the negative correlation enhances Z11′R and γ11′R, and no correlation slightly enhances Z11′R and γ11′R, in comparison with nonreactive Z11′ and γ11′. The larger the value of the mean retardation factor, the large its effect on Z11′R and γ11′R. The three‐dimensional Z11′R and γ11′R are slightly larger than their respective two‐dimensional counterparts.
NMR‐derived model of interconverting conformations of an ICAM‐1 inhibitory cyclic nonapeptide
Authors: Sillerud L.O. , Burks E.J. , Wester M.J. , Brown D.C. , Vijayan S. , Larson R.S.
Published: August 2003

Abstract:  We have produced by phage‐display a disulfide‐linked cyclic nonapeptide (inhibitory peptide‐01, IP01), CLLRMRSIC, that binds to intracellular adhesion molecule‐1 (ICAM‐1) and blocks binding to its counter‐structure, leukocyte functional antigen‐1 (LFA‐1). As a first step towards improving its pharmacologic properties, we have performed a structural and functional analysis of this peptide inhibitor to determine the features relevant to ICAM‐1 binding. We report here the solution model of our initial product, IP01, as derived from two‐dimensional nuclear magnetic resonance (NMR) restraints and molecular modeling. Distance and dihedral angle restraints, generated from nuclear Overhauser effect spectroscopy (NOESY) and one‐dimensional‐NMR experiments respectively, were used to generate an ensemble of structures using distance geometry and simulated annealing. Molecular dynamic simulations produced three interconverting conformational families consistent with the NMR‐derived constraints. We describe these conformations and their mechanism of interconversion. Furthermore, we have measured the IC50 s of a series of inhibitors generated from IP01 through alanine substitution of each residue. These results show that the L2‐L3‐R4‐M5‐R6 segment is functionally active, conformationally flexible, and contains a β‐turn involving residues R4‐S7, while the C1‐C9‐I8‐S7 segment is less functionally‐active but adopts a more defined solution conformation, consistent with a scaffolding function. This model will be useful for designing nonpeptide‐based organic inhibitors with improved pharmacologic properties.
Model studies of the function of blockers on the small conductance potassium ion channel
Authors: Ciechanowicz‐Rutkowska M. , Lewinski K. , Oleksyn B. , Stec B.
Published: August 2003

Abstract: A correlation between KI (equilibrium dissociation constants) and IC50 (concentration at 50% inhibition) inhibitors for the family of blockers of the small conductance potassium ion channels and their intrinsic characteristics like molecular mass and volume have been investigated. Most of the blockers in the family are not selective, in contrast to apamin – an 18 amino acid bee venom toxin – that is known to be a highly potent and selective blocker of these channels. Differences and similarities between the blockers have been analyzed, pointing toward the origin of their selectivity and relative potency. In conclusion, an ion channel blocking is a process controlled mainly by diffusion, in accordance with previous experimental results.
Multigene DNA prime‐boost vaccines for SHIV89.6P
Authors: Doria‐Rose Nicole A. , Pierce Christopher C. , Hensel Michael T. , Sutton William F. , Sheikh Nadeem , Polacino Patricia , Kuller LaRene , Zhu Yong‐De , Hu Shiu‐Lok , David Anderson  , Haigwood Nancy L.
Published: August 2003

We assessed four prime‐boost vaccine regimens with a Gene Gun component for SHIV89.6P in Macaca nemestrina. A dosing experiment using β‐galactosidase plasmid showed that 30 or 45 shots per dose elicited higher titer antibody than smaller doses. For SHIV89.6P, we administered a six‐plasmid vaccine capable of producing non‐infectious virions in vivo in combination with either vaccinia recombinants or inactivated virus. DNA prime/vaccinia boost, or the reverse, elicited strong immune responses. The SHIV89.6P challenge virus was grown in M. nemestrina peripheral blood mononuclear cells and titered in vivo intrarectally. As has been observed for SHIV89.6P in M. mulatta, the infected M. nemestrina experienced rapid and severe loss of circulating CD4+ T cells. Vaccinated macaques were challenged three weeks after the last boost. DNA prime/vaccina boost or vaccina prime/DNA boost protected 11/12 animals from acute CD4+ T cell depletion and disease, while other regimens were not effective.
Expression of IFN‐γ induced CXCR3 agonist chemokines and compartmentalization of CXCR3+ cells in the periphery and lymph nodes of rhesus macaques during simian immunodeficiency virus infection and acquired immunodeficiency syndrome
Authors: Sarkar Surojit , Kalia Vandana , Murphey‐Corb Michael , Montelaro Ronald C. , Reinhart Todd A.
Published: August 2003

Abstract:  Dysregulation of cytokines and chemokines during human immunodeficiency virus 1 (HIV‐1) and simian immunodeficiency virus (SIV) infection is thought to be critical in the progression of acquired immunodeficiency syndrome (AIDS). To evaluate the potential role of Th1‐agonist chemokines in disease progression during AIDS, we assessed CXCL9/MIG and CXCL10/IP‐10 expression simultaneously in the periphery and lymphoid tissues of SIV‐infected animals at a single‐cell level by flow cytometry. We optimized intracellular staining and analysis of CXCL9/MIG and CXCL10/IP‐10 production in human leukocyte antigen (HLA)‐DR+ macaque cells by flow cytometry using cross‐reactive antibodies against human chemokines. We observed an upregulation of CXCL9/MIG and CXCL10/IP‐10 production in both the periphery and lymph nodes of infected animals compared with naïve controls. Animals with higher viral loads had higher levels of CXCL9/MIG and CXCL10/IP‐10 producing cells compared with animals with low viral loads. Analysis of cells bearing the receptor (CXCR3) for CXCL9/MIG and CXCL10/IP‐10 revealed increased number of CXCR3+ cells in the lymph nodes of infected animals. Importantly, an inverse correlation (P < 0.05) between CXCL9/MIG and CXCL10/IP‐10 production, both in the periphery and lymph nodes, and peripheral CD4+ T‐cell numbers was observed. These findings provide further evidence that dysregulation of Th1 agonist chemokines might contribute to the ultimate immunopathology during AIDS.
Isolate‐dependent impacts of fungal endophytes in a multitrophic interaction
Authors: Bultman Thomas L. , McNeill M. R. , Goldson S. L.
Published: August 2003

Neotyphodium lolii, an endophytic fungus of perennial ryegrass, deters Argentine stem weevil, Listronotus bonariensis, an important insect pest of pastures in New Zealand. Deterrence is apparently due to several alkaloids the fungus produces. We asked if the fungus also affects the third trophic level. Specifically, we tested if several different isolates of the fungus altered the growth and survival of the parasitoid, Microctonus hyperodae. Adult weevils were collected from paddocks near Lincoln, New Zealand and maintained in an environmental chamber. Weevils were assorted into treatment groups and fed perennial ryegrass (cv. Nui) lacking endophyte infection (nil) or containing one of the following endophyte strains: ARW, AR1, AR6, AR37. All endophyte strains differed from one another with respect to the profile of alkaloids they produce. Following two weeks of acclimation, weevils were placed with M. hyperodae to allow for parasitization. Weevils were then placed into Petri dishes (10 per dish) and fed grass clippings from the appropriate treatment group. We collected weevils as they died and dissected them to assess the development of parasitoids. Emergence of prepupae from hosts and survival to adulthood were also recorded.

 Fungal isolates did not differ in their influence on weevil feeding or survival. In contrast, the effect of the endophyte on the parasitoid varied among isolates of the fungus. Isolates ARW and AR6 reduced parasitoid adult emergence relative to nil endophyte. In contrast, AR37 had no negative effect on survival of the parasitoid. Furthermore, an index of developmental rate showed that parasitoids developed more slowly when reared from hosts fed grass containing any of the strains of N. lolii, except AR37, compared to endophyte‐free grass. Negative effects of the endophyte on parasitoid survival were associated with the presence of ergovaline while effects on parasitoid development rate were associated with the presence of any alkaloid.
Local texture convergence: a new approach to seeking assembly rules
Authors: Watkins AJ. , Wilson J. Bastow
Published: August 2003

Much of community‐ecology theory describes (or even assumes) constraints on the coexistence of species. These constraints are often described using functional characters as an index to the niche of the species. The hypothesis/assumption is that those species which are too similar in functional characters, and hence in niche, cannot coexist. However, this body of theory is rarely tested. We attempted a test by making a prediction of texture convergence that follows logically from the theory, yet is simple enough to test – one based on similarity of ecological assembly between the patches of a community. We used replicate quadrats within twelve herbaceous communities. Eleven characters were measured, that were intended to reflect the functional above‐ground niche of the species. We examined each character in turn, to test for ecological convergence to a similar mean within each community, with species either weighted equally (i.e. using species presence) or weighted by their biomass. Convergence with species weighted by their biomass was seen in chlorophyll content, indicating a significant tendency for each patch in a community to comprise a rather constant mixture of species types in terms of their different chlorophyll contents. In terms of species presence, texture divergence occurred in leafiness (LAR), specific leaf area (SLA) and leaf inclination, i.e. there was more variation between quadrats within a site than expected at random. However, significant results were sparse: the bulk of evidence is for no significant departure from a null model, i.e. no support for a widespread body of ecological theory.
Within‐brood distribution of ectoparasite attacks on nestling blue tits: a test of the tasty chick hypothesis using inulin as a tracer
Authors: Simon A. , Thomas D. W. , Blondel J. , Lambrechts M. M. , Perret P.
Published: August 2003

Blow fly (Protocalliphora spp.) larvae are nest ectoparasites that compete with nestlings for resources by feeding on blood. Their main direct consequences on nestlings are a reduction in growth, blood parameters, and physiological performance. The impact of Protocalliphora larvae on nestling development can be extremely variable between nests within years and between years due to varying food availability. However, there is also considerable within‐nest variation in nestling growth and development which has been attributed to an aggregation of ectoparasites on less resistant chicks; the tasty chick hypothesis. We tested for aggregated attacks of Protocalliphora within broods of nestling blue tits using radio‐labelled inulin to trace plasma, and hence blood, turnover. To estimate blood removal by Protocalliphora, we compared inulin turnover in naturally parasitized and experimentally deparasitized nestlings. Inulin turnover, and hence the blood loss attributed to Protocalliphora attacks, was significantly correlated with chick mass and size rank within the brood, with the smallest and lowest‐ranking chicks showing greatest inulin turnover. This is the first study demonstrating non‐random blood‐feeding by Protocalliphora larvae, a phenomenon which can render the statistical detection of their impact problematical by increasing within‐brood variance in developmental and physiological measures.
Life‐history trade‐off in two predator species sharing the same prey: a study on cassava‐inhabiting mites
Authors: Magalhães S. , Brommer J. E. , Silva E. S. , Bakker F. M. , Sabelis M. W.
Published: August 2003

In cassava fields, two species of predatory mites, Typhlodromalus aripo and T. manihoti, co‐occur at the plant level and feed on Mononychellus tanajoa, a herbivorous mite. The two predator species are spatially segregated within the plant: T. manihoti dwells on the middle leaves, while T. aripo occurs in the apices of the plant during the day and moves to the first leaves below the apex at night.

To monitor the prey densities experienced by the two predator species in their micro‐environment, we assessed prey and predator populations in apices and on the leaves of cassava plants in the field. Prey densities peaked from November to January and reached the lowest levels in July. They were higher on leaves than in the apices. To test whether the life histories of the two predator species are tuned to the prey density they experience, we measured age‐specific fecundity and survival of the two predators under three prey density regimes (1 prey female/72 h, 1 prey female/24 h and above the predators level of satiation). T. manihoti had a higher growth rate than T. aripo at high prey densities, mainly due to its higher fecundity. T. aripo had a higher growth rate at low prey density regimes, due to its late fecundity and survival. Thus, each of the two species perform better under the prey density that characterizes their micro‐habitat within the plant.
Functional equivalence of non‐lethal effects: generalized fish avoidance determines distribution of gray treefrog, Hyla chrysoscelis, larvae
Authors: Binckley Christopher A. , Resetarits Jr. William J.
Published: August 2003

How patterns of prey abundance are generated determines how predation influences population and community level dynamics. We investigated how a natural population of ovipositing treefrogs, Hyla chrysoscelis, partitioned their eggs amongst experimental ponds differing in the non‐lethal presence of five fish predators, each representing a distinct family. Four fish predators were functionally equivalent in terms of the behavioral response they induced in H. chrysoscelis females and hence the distribution of larval H. chrysoscelis. Mean number of H. chrysoscelis eggs deposited was significantly decreased by the mere presence of these predators relative to controls, with three species eliciting a complete avoidance (e.g. no eggs deposited). One fish predator, Aphredoderus sayanus, was statistically indistinguishable from the control treatment. These data mimic patterns of species distribution observed in nature in response to the presence of fish, but suggest an alternative mechanism for generating patterns of prey abundance amongst habitats differing in their predator composition. Furthermore, our results expand the importance of predator induced non‐lethal effects as a process that could dramatically affect population and community level dynamics.
Coupling the cell cycle to cell growth
Authors: Boye Erik , Nordström Kurt
Published: August 2003

In order to multiply, both prokaryotic and eukaryotic cells go through a series of events that are collectively called the cell cycle. However, DNA replication, mitosis and cell division may also be viewed as having their own, in principle independent, cycles, which are tied together by mechanisms extrinsic to the cell cycle—the checkpoints—that maintain the order of events. We propose that our understanding of cell‐cycle regulation is enhanced by viewing each event individually, as an independently regulated process. The nature of the parameters that regulate cell‐cycle events is discussed and, in particular, we argue that cell mass is not such a parameter.
Gli proteins and the control of spinal‐cord patterning
Authors: Jacob John , Briscoe James
Published: August 2003

The secreted protein sonic hedgehog (Shh) is crucial for the specification of neuronal subtype identity in the vertebrate neural tube. Zinc‐finger proteins of the Gli family are known to be transcriptional mediators of Shh signalling, and to coordinately pattern the dorsal–ventral axis of the spinal cord. Recent studies indicate that additional signals may provide positional information in parallel to Shh to specify neuronal fate in this tissue. We review the role of Gli proteins in spinal‐cord development and propose that various upstream patterning signals may be integrated by the Gli proteins to direct a coherent programme of neurogenesis.
Integrin‐α3 mediates binding of Chordin to the cell surface and promotes its endocytosis
Authors: Larraín Juan , Brown Carlos , De Robertis Eddy M
Published: August 2003

Dorsoventral patterning in animal development is regulated by a morphogenetic gradient of Bone morphogenetic protein signalling, which is established by a set of proteins that are conserved from Drosophila to vertebrates. These include Chordin (Chd)/Short gastrulation, Xolloid/Tolloid and Twisted gastrulation. Here, we report the identification of a cell‐surface component of this morphogenetic pathway. Prompted by the observation that Chd protein bound to the surface of certain cell lines with subnanomolar affinity, we identified two cell‐surface proteins that bind to Chd, one of which corresponds to Integrin‐α3. Integrin‐α3 and Chd are co‐expressed in the Xenopus embryo. Transfection of Integrin‐α3 increased the binding of Chd to the cell surface, which was competed by an excess of soluble Integrin‐α3. After binding to the cell surface, Chd was translocated into intracellular endocytic compartments in a temperature‐dependent manner. We propose that Integrin‐α3 may regulate the concentration of Chd protein in the extracellular space by endocytosis.
Effect of CpG methylation on RAG1/RAG2 reactivity: implications of direct and indirect mechanisms for controlling V(D)J cleavage
Authors: Nakase Hiroshi , Takahama Yousuke , Akamatsu Yoshiko
Published: August 2003

It has been suggested that DNA methylation/demethylation is involved in regulating V(D)J rearrangement. Although methylated DNA is thought to induce an inaccessible chromatin structure, it is unclear whether DNA methylation can directly control V(D)J recombination independently of chromatin structure. In this study, we tested whether DNA methylation directly affects the reactivity of the RAG1/RAG2 complex. Specific methylation within the heptamer of the recombination signal sequences (RSS) markedly reduced V(D)J cleavage without inhibiting RAG1/RAG2–DNA complex formation. By contrast, methylation at other positions around the RSS did not affect the reactivity of the RAG proteins. The presence of a methyl‐CpG binding‐domain protein inhibited the binding of the RAG1/RAG2 complex to all the methylated CpG sites that were tested. Our findings suggest that DNA methylation around the RSS may have a previously unexpected function in regulating V(D)J recombination by directly inhibiting V(D)J cleavage, in addition to its general function of inducing an inaccessible chromatin configuration.
Pre‐medication with pronase reduces artefacts during endoscopic ultrasonography
Authors: Sakai N. , Tatsuta M. , Iishi H. , Nakaizumi A.
Published: August 2003

Background : Gastric mucus usually induces artefacts during endoscopic ultrasonography.

Aim : To investigate the effectiveness of pre‐medication with the proteolytic enzyme, pronase, before endoscopic ultrasonography.

Methods : Out‐patients scheduled for endoscopic ultrasonography were randomly assigned to oral pre‐medication with the anti‐foam agent, dimethylpolysiloxane, alone (treatment A; n = 29), with dimethylpolysiloxane plus sodium bicarbonate (treatment B; n = 29) or with dimethylpolysiloxane, sodium bicarbonate and pronase (treatment C; n = 29). All drinks were given about 10 min before the start of the procedure. After insertion of the endoscope, endoscopists recorded visibility scores before the procedure, imaging scores at endoscopic ultrasonography and the numbers of high‐echo spots in the gastric cavity and on the gastric wall surface after the procedure.

Results : Pre‐medication with pronase (treatment C) significantly reduced (both at P < 0.05) the visibility score (score 4, 46%) in comparison with that obtained for pre‐medication without pronase (10% for both treatments A and B). Treatment with pronase significantly reduced (both at P < 0.05) the endoscopic ultrasonography score in the gastric cavity (score 4, 34%) in comparison with that found for treatments A (7%) and B (0%). It also significantly reduced (P < 0.05) the endoscopic ultrasonography score on the gastric wall surface (score 4, 14%) in comparison with that observed for treatment A (3%). The numbers of high‐echo spots in the gastric cavity and on the gastric wall surface were significantly less (both at P < 0.001) for pre‐medication with pronase (treatment C) than for pre‐medication with treatments A and B. There were no complications associated with the solutions.

Conclusions : Pre‐treatment with pronase reduced the artefacts during endoscopic ultrasonography.
The mechanisms of prednisone inhibition of inflammation in Crohn's disease involve changes in intestinal permeability, mucosal TNFα production and nuclear factor kappa B expression
Authors: Wild G. E. , Waschke K. A. , Bitton A. , Thomson A. B. R.
Published: August 2003

Background : The clinical course of Crohn's disease after the induction of remission with medical therapy is characterized by unpredictable relapse.

Aim : To evaluate three surrogate markers, intestinal permeability, mucosal TNFα and nuclear factor (NF)‐κB/IκBα expression, in order to determine the relationship of these parameters to clinical relapse.

Methods : Thirty patients with active Crohn's disease were treated with a 10 week course of prednisone using a tapering dosing regimen. Intestinal permeability (lactulose/mannitol [L/M ratio]) was determined at baseline and at the end of prednisone tapering. TNFα production and the levels of expression of NF‐κB/IκBα were measured in colonic mucosal biopsies obtained after the induction of remission.

Results : Twenty‐two patients (73%) achieved remission and 50% of patients experienced a clinical relapse during the ensuing 12 months. Treatment with prednisone resulted in a significant decrease in the L/M ratio. Of the patients that relapsed, 75% had a raised L/M ratio at the time of remission compared with 20% of patients with a normal L/M ratio (P < 0.008; hazard ratio = 6.094; CI 1.55, 17.43). Mucosal TNFα production was greater in relapsers compared with those who remained in remission. The levels of NF‐κB in relapsers were significantly greater and levels of cytosolic IκBα were significantly lower compared with those measured in patients who remained in remission.

Conclusions : These findings underscore the importance of incorporating biological parameters of inflammation in determining the clinical course of Crohn's disease.
Long‐term results of low‐dose intravenous ciclosporin for acute severe ulcerative colitis
Authors: Rayner C. K. , McCormack G. , Emmanuel A. V. , Kamm M. A.
Published: August 2003

Background : Intravenous ciclosporin for acute, severe colitis is usually administered in a dose of 4 mg/kg/day, with concurrent intravenous steroids. This is associated with considerable morbidity. We have been using a low‐dose regimen, most commonly without concurrent steroids, for seven years, and present the outcome.

Methods : Records of all patients admitted for severe ulcerative colitis, treated by one physician over seven years, were reviewed.

Results : Thirty‐one patients received low‐dose intravenous ciclosporin (2 mg/kg/day) for a median 8 days. Eleven early patients received concurrent intravenous corticosteroids. Three patients had hypertension requiring dose reduction, one elevated creatinine and one elevated liver enzymes (all transient), and four experienced infection (two arm cellulitis, one perianal abscess, one post‐operative wound infection). Twenty‐four patients (77%) avoided urgent colectomy, and were discharged on oral ciclosporin and azathioprine. After a median 18 months (range 3–77), 14 patients (45% of total) avoided colectomy, of whom eight had flares responding to medical therapy and two had persistent, mildly active disease.

Conclusions : Low‐dose intravenous ciclosporin (2 mg/kg/day), usually used as a monotherapy and followed by azathioprine, achieves similar long‐term efficacy to higher dose ciclosporin combined with steroids in severe acute ulcerative colitis. Morbidity appears to be low.
The management of acute variceal bleeding
Authors: Ferguson J. W. , Tripathi D. , Hayes P. C.
Published: August 2003

Variceal haemorrhage is a common medical emergency with a high mortality (30–50%). Adequate resuscitation is vital, and once stabilised the patient should be moved to a high‐dependency area. Antibiotics reduce mortality, and the vasoactive drug terlipressin should be administered if early endoscopy is unavailable. Early endoscopy is essential both to make the diagnosis and to allow therapeutic measures to be performed. The evidence suggests that variceal band ligation is the most effective therapy for oesophageal varices. If gastric varices are found at the index endoscopy the evidence at present is inadequate to be certain which is the best treatment, but both endoscopic therapy with cyanoacrylate or thrombin and transjugular intrahepatic portosystemic stent shunt (TIPSS) have been reported to be of benefit. When initial treatments fail, rescue therapy should be initiated. Most authorities agree that TIPSS is the rescue therapy of choice. Many questions remain concerning the treatment of acute variceal bleeding, particularly the ideal therapy for gastric varices and the role of combination vasoactive and endoscopic therapy. Randomised controlled trials are required to answer these important issues.
Double‐blinded placebo‐controlled study of Phyllanthus urinaris for the treatment of chronic hepatitis B
Authors: Chan H. L.‐Y. , Sung J. J.‐Y. , Fong W.‐F. , Chim A. M.‐L. , Yung P.‐P. , Hui A. Y. , Fung K.‐P. , Leung P.‐C.
Published: August 2003

Background : Previous studies suggested that Phyllanthus species have an anti‐viral effect on hepatitis B, but methodologies have been inadequate.

Aims : This study aimed to investigate the anti‐viral effect of Phyllanthus urinaris.

Methods : Chronic hepatitis B patients with positive hepatitis B e‐antigen (HBeAg), hepatitis B virus (HBV) DNA > 500 000 copies/mL and elevated alanine transaminase (ALT) were recruited. Patients were randomized into groups of 12 receiving P. urinaris 1, 2 and 3 g three times daily for 6 months or placebo (six cases). The primary endpoint was HBV DNA reduction, and secondary endpoints were HBeAg seroconversion and ALT normalization.

Results : On an intention‐to‐treat analysis there was no difference in log10[HBV DNA] reduction of the Phyllanthus 1‐g (0.18 ± 1.42), 2‐g (0.33 ± 1.08) and 3‐g (0.85 ± 1.30) groups vs. placebo (0.28 ± 0.85) (P = 0.90, 0.92 and 0.38, respectively) at the end of treatment. The percentage of patients among the placebo, Phyllanthus 1‐g, 2‐g and 3‐g groups undergoing HBeAg seroconversion (0%, 9.1%, 8.3% and 16.7%, respectively) and ALT normalization (0%, 0%, 8.3% and 33.3%) were not significantly different at the end of treatment. No delayed virological or biochemical response was documented at 24 weeks after the cessation of treatment. No serious adverse event was reported.

Conclusion : P. urinaris treatment for 6 months has no demonstrable anti‐viral effect in chronic hepatitis B.
Acute respiratory distress syndrome: an audit of incidence and outcome in Scottish intensive care units
Authors: Hughes M. , MacKirdy F. N. , Ross J. , Norrie J. , Grant I. S. ,   on behalf of the Scottish Intensive Care Society
Published: August 2003

This prospective audit of incidence and outcome of the acute respiratory distress syndrome was conducted as part of the national audit of intensive care practice in Scotland. All patients with acute respiratory distress syndrome in 23 adult intensive care units were identified using the diagnostic criteria defined by the American‐European Consensus Conference. Daily data collection was continued until death or intensive care unit discharge. Three hundred and sixty‐nine patients were diagnosed with acute respiratory distress syndrome over the 8‐month study period. The frequency of acute respiratory distress syndrome in the intensive care unit population was 8.1%; the incidence in the Scottish population was estimated at 16.0 cases.100 000−1.year−1. Intensive care unit mortality for acute respiratory distress syndrome was 53.1%, with a hospital mortality of 60.9%. In our national unselected population of critically ill patients, the overall outcome is comparable with published series (Acute Physiology and Chronic Health Evaluation II standardised mortality ratio = 0.99). However, mortality from acute respiratory distress syndrome in Scotland is substantially higher than in recent other series suggesting an improvement in outcome in this condition.
Comparative evaluation of methods for ensuring the correct position of the tracheal tube in children undergoing open heart surgery*
Authors: Kim Kyoung Ok , Um Woo Sik , Kim Chong Sung
Published: August 2003

Summary The length of the trachea varies and is relatively short in children, it is therefore difficult to determine the correct depth of tracheal tube placement. In 85 children, the tube was placed using one of the following methods: (i) after deliberate endobronchial intubation, withdrawal to the carina was confirmed by auscultation, and the tube was then withdrawn a further 2 cm (auscultation group); (ii) as above, except that withdrawal to the carina was confirmed by a decrease in peak inspiratory pressure (pressure group); (iii) the tube was placed with a 3.0‐cm mark at the vocal cords (mark group). The mean (SD) distance from the tip of the tube to the carina was 1.91 (0.81) cm in the auscultation group, and 1.93 (0.67) cm in the pressure group. These were not significantly different (p > 0.05) from targeted distance of 2 cm. In the mark group, the tube was located 2.30 (0.98) cm above the carina in children younger than 36 months and was further from the carina [6.16 (1.0) cm] in older children. In 20% of patients initially randomly allocated to the mark group, the mark could not be visualised. In conclusion, the methods described above effectively achieve adequate tracheal tube depth in children.
A comparison of the forces exerted during laryngoscopy using disposable and non‐disposable laryngoscope blades
Authors: Evans A. , Vaughan R. S. , Hall J. E. , Mecklenburgh J. , Wilkes A. R.
Published: August 2003

Summary The concern that re‐usable equipment may be a source of cross‐infection has prompted the increased use of disposable laryngoscope blades. We conducted a study investigating the duration of laryngoscopy and the peak force generated using various laryngoscope blades. Five blades were studied: one reusable Macintosh 3 blade, one disposable metal blade and three plastic disposable blades. Sixty anaesthetists performed laryngoscopy on a mannequin using each of the five blades presented in a random order. This was then repeated with a rigid collar applied to the mannequin. The mean force applied with the collar off with the metal blades was 32.8 and 30.8 N, and with the plastic blades 37.3, 39.6 and 41.5 N, respectively (p < 0.0001). The mean force applied with the collar on with the metal blades was 30.5 and 32.5 N, and with the plastic blades 35.5, 34.9 and 31.4 N, respectively (p < 0.0001). The mean duration of laryngoscopy with the collar off for the metal blades was 5.6 and 5.4 s, and with the plastic blades 10, 7.2 and 7.5 s (p < 0.0001). The duration of laryngoscopy with the collar applied for the metal blades was 7.1 and 7.5 s, and with the plastic blades 11.8, 9.7 and 9.0 s (p < 0.0001). The use of plastic blades results in both greater peak force and duration of laryngoscopy.
Natal Attraction in Adult Female Baboons (Papio cynocephalus ursinus) in the Moremi Reserve, Botswana
Authors: Silk Joan B. , Rendall Drew , Cheney Dorothy L. , Seyfarth Robert M.
Published: August 2003

Mammalian females are strongly attracted to infants and interact regularly with them. Female baboons make persistent attempts to touch, nuzzle, smell and inspect other females’ infants, but do not hold them for long periods, carry them, or provide other kinds of care for them. Mothers generally tolerate these interactions, but never initiate them. The function of these brief alloparental interactions is not well understood. Infant handling might be a form of reproductive competition if females’ interest in infants causes distress to mothers or harm to their infants. Alternatively, infant handling might be the product of selection for appropriate maternal care if females who are highly responsive to infants are the most successful mothers. We test several predictions derived from these hypotheses with data collected in a free‐ranging group of baboons (Papio cynocephalus ursinus) in the Moremi Reserve of Botswana. Infants were most attractive when they were very young. Mothers of young infants were approached by other adult females on average once every 6 min, and other females attempted to handle their infants approximately once every 9 min. By the time infants were a year old, their mothers were being approached only once every 30 min and infants were being handled only once every 5 h. Females were more strongly attracted to other females’ infants when they had young infants of their own, and their interest in other females’ infants declined as their own infants matured. Females seemed to be equally attracted to all infants, but had greater access to offspring of their relatives and subordinate females. Females nearly always grunted as they handled infants. As in other contexts grunts are a reliable predictive signal that non‐aggressive behavior will follow, the use of grunts before handling suggests that these interactions were not a form of deliberate harassment.
Male Rock Sparrow (Petronia petronia) Nest Defence Correlates with Female Ornament Size
Authors: Griggio Matteo , Matessi Giuliano , Pilastro Andrea
Published: August 2003

We investigated the relationship between male nest defence and female breast patch size in an alpine population of rock sparrow (Petronia petronia) in northern Italy. We presented a mounted weasel (Mustela nivalis), a common nest predator, to 28 pairs breeding in nest boxes, with 12–13‐d‐old nestlings, and measured the intensity of male and female defence reaction. We measured the frequency of attack flights, intensity of alarm calling and total time spent in view, and then combined these for each individual, in a single defence factor by principal component analysis. All the females arrived to defend the nest while only 21 males arrived, and females defended the nest more intensely than males. We analysed, by stepwise regression, the relationship of male defence factor to female behaviour and phenotype (breast patch size, a measure of quality) and brood properties (size, mass, phenology). Male defence factor was significantly related only to female breast patch size. We argue that male rock sparrows apparently make parental investment decisions according to their mate's quality, and examine possible alternative hypotheses.
Influence of Body Size on the Responses of Fathead Minnows, Pimephales promelas, to Damselfly Alarm Cues
Authors: Mirza Reehan S. , Chivers Douglas P.
Published: August 2003

A wide diversity of aquatic organisms release chemical alarm cues upon encountering or being attacked by a predator. These alarm cues can be used by nearby individuals to assess local predation risk. Receivers warned by chemical alarm cues gain a survival benefit when encountering predators. Animals that are in the same prey guild (i.e. that co‐occur and share the same predators) may learn to recognize each others’ chemical alarm cues. This ability may confer an adaptive advantage if the prey animals are vulnerable to the same predators. However, if the prey grow to different sizes and as a consequence are no longer vulnerable to the same suite of predators, then there should no longer be an advantage for the prey to respond to each others’ alarm cues. In this study, we exposed small and large fathead minnows (Pimephales promelas) to cues from syntopic injured damselfly larvae (Enallagma boreale), cues from injured mealworm larvae (Tenebrio molitor) and to distilled water. Small minnows exhibited antipredatory behaviour and increased shelter use in response to injured damselfly cues but not to the controls of injured mealworm or distilled water. On the contrary, large minnows exhibited no significant change in shelter use in response to any of the injured cues. These data demonstrate that fathead minnows exhibit an antipredator response to damselfly alarm cues, but only when minnows are small and members of the same prey guild as damselfly larvae. These results demonstrate the considerable flexibility in the responses to heterospecific alarm cues.
Evaluation of entomopathogenic nematodes for control of the beetle, Luperomorpha suturalis Chen (Col., Chrysomelidae)
Authors: Yang X. , Jian H. , Liu Z. , Yang H. , Yuan J. , Quanli Z. , Shuangyue L.
Published: August 2003

Abstract: The strains Steinernema feltiae Otio and A54, Steinernema ceratophorum D43 and Steinernema carpocapsae BJ were tested for their infectivity to the larvae and pupae of beetle (Luperomorpha suturalis Chen) at 25 ± 0.5°C and 15 ± 0.5°C in laboratory conditions. The results, based on comparison of the insect mortalities and nematode penetration rates among four nematode strains, showed that S. feltiae Otio was a potential biocontrol agent of the larvae and pupae of L. suturalis. The mortalities of the larvae and pupae exposed to S. feltiae Otio strain were 95.8 and 97.1% at 25 ± 0.5°C and 78.0 and 83.0% at 15 ± 0.5°C, respectively. The nematode penetration rates of S. feltiae Otio of the larvae and pupae were 15.6 and 19.0% at 25 ± 0.5°C, 2.6 and 6.3% at 15 ± 0.5°C, respectively. Field efficacy of S. feltiae Otio strain was examined against beetle larvae in Hebei province, northern China. The population reduction of insect larvae was 77.8 and 13.9% at doses of 30 and 15 infective juveniles (IJs)/cm2 of S. feltiae Otio after 38 days of treatment and 90.2 and 92.4% after 100 days of treatment. However, the population of the insect larvae was reduced only to 15.5 and 15.7% when treated with pesticide after 38 and 100 days, respectively. The efficiency between the two nematode doses was not significantly different but it was remarkably higher than that of the pesticide after 100 days of application. The results suggest that S. feltiae Otio strain could be an alternative to pesticide for beetle control.
Diet of Zonocerus variegatus (Linné, 1758) (Orth., Acrididae) in cassava fields in Bénin
Authors: Le Gall Ph. , Djihou Z. , Tchenga G. , Lomer Ch. J.
Published: August 2003

Abstract:  This paper presents the results of a study on the diet of Zonocerus variegatus in cassava agro‐ecosystems at Allada, south Benin. The diet was determined by the analysis of plant fragments in the faeces of insects sampled in the fields. The grasshoppers studied consumed 21 plant species among the 81 found in the fields. Cassava, maize, Mallotus oppositifolius and Chromolaena odorata were the major food plants for Z. variegatus in this system. The presence of Z. variegatus in different fields was observed depending on the season and the presence of certain plant species. There was no relationship between plant frequency in the diet and in the field. Cassava was the preferred food resource for mature nymphs and adults. During the dry season, young nymphs stayed near the hatching sites and where good food resources were available. At this time, the grasshoppers were present in a field where cassava was not abundant but where maize and weeds were available. During the dry season, Z. variegatus had a broader diet than during the wet season. This contradicts the current hypothesis that the water content of plants and the floral diversity determines food preference. The dry season is also the time when C. odorata leaves were found in the faeces of both adults and nymphs. These observations made in West Africa are similar to those made in Central Africa, particularly for the number of plant species found in the faeces, 21 (26% of all plant species found in the fields) in Bénin and 17 (23%) in the Congo. The increase of the sample size and the great differences between the ecoregional situation of the study sites do not substantially change the number of plant species included in the diets. In the area covered by this study, C. odorata is not the major substitute for cassava during the dry season, although it remains a major food source and an especially visible food resource.
Effects of the timing of applications on the incompatibility of three fungicides and one isolate of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina)
Authors: Kouassi M. , Coderre D. , Todorova S. I.
Published: August 2003

Abstract: The effect of timing of application on the incompatibility of three fungicides (metalaxyl, mancozeb, copper oxide) and isolate MK2001 of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin was assessed in vitro. Isolate MK 2001 at 1 × 107 conidia/ml concentration was highly pathogenous to adults of Lygus lineolaris (Hemiptera) (84% mortality at day 4 post‐treatment). The fungicides at the manufacturer recommended rate (1X) were strongly fungistatic and inhibited the fungal isolate radial growth on Sabouraud dextrose agar (SDA). Mancozeb, metalaxyl and copper oxide exhibited insecticidal activity of 24, 40 and 48% respectively, on L. lineolaris adults. It is clear that application of the fungal isolate MK2001 2–4 days before applying fungicides metalaxyl, mancozeb or copper oxide synergized the insecticidal effect of the isolate. On the contrary, application of metalaxyl, mancozeb, copper oxide 2–4 days before applying isolate MK2001 antagonized the insecticidal effect. The simultaneous use of each fungicide (metalaxyl, mancozeb or copper oxide) and the isolate gave lesser insect mortality. This study revealed that although some fungicides are incompatible for use alongside fungal isolates, the proper evaluation of their time of use could be beneficial in biological control or IPM programmes. Furthermore, the application of B. bassiana isolate MK2001 followed by fungicide application could synergize insecticidal activity.
The effects of triflumuron against the western flower thrips (Frankliniella occidentalis (Pergande)) on pepper: an evaluation based on the analysis of population dynamics
Authors: Vacante V. , Gilioli G.
Published: August 2003

Abstract:  The population response of western flower thrips, Frankliniella occidentalis (Pergande) to triflumuron, growth regulator of the benzoyl‐phenyl‐urea group which performs a chitin‐inhibiting action, was the subject of an experimental field test. The characteristics of the active ingredient (knock‐down effect, temporal persistence and overall effect of the substance) were assessed in comparison with the responses of two synthetic insecticides (methiocarb, chlorpyrifos‐methyl) and in relation to the different treatment strategies (number and dates of treatments). The results of the experimental tests were analysed using a specially developed innovative method, which allows to evaluate precisely and in quantitative terms the response of the system (modification in the population dynamics of thrips) to the treatment carried out. The observations performed highlight that, at the considered doses, triflumuron is characterized by a weak knock‐down effect but by good temporal persistence which makes it a product endowed with a distinct larvicidal activity. Furthermore, its action is better overall than that of chlorpyrifos‐methyl and is comparable with that of methiocarb.