bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of taxonomic standardization on sampling-standardized estimates of historical diversity
Authors: Wagner Peter J , Aberhan Martin , Hendy Austin , Kiessling Wolfgang
Published: November 2006

Occurrence-based databases such as the Palaeobiology database (PBDB) provide means of accommodating the heterogeneities of the fossil record when evaluating historical diversity patterns. Although palaeontologists have given ample attention to the effects of taxonomic practice on diversity patterns derived from synoptic databases (those using first and last appearances of taxa), workers have not examined the effects of taxonomic error on occurrence-based diversity studies. Here, we contrast diversity patterns and diversity dynamics between raw data and taxonomically vetted data in the PBDB to evaluate the effects of taxonomic errors. We examine three groups: Palaeozoic gastropods, Jurassic bivalves and Cenozoic bivalves. We contrast genus-level diversity patterns based on: (i) all occurrences assigned to a genus (i.e. both species records and records identifying only the genus), (ii) only occurrences for which a species is identified, and (iii) only occurrences for which a species is identified, but after vetting the genus to which the species is assigned.

Extensive generic reassignments elevate origination and extinction rates within Palaeozoic gastropods and origination rates within Cenozoic bivalves. However, vetting increases generic richness markedly only for Cenozoic bivalves, and even then the increase is less than 10%. Moreover, the patterns of standing generic richness are highly similar under all three data treatments. Unless our results are unusual, taxonomic standardization can elevate diversity dynamics in some cases, but it will not greatly change inferred richness over time.
Mechanical design of walking machines
Authors: Arikawa Keisuke , Hirose Shigeo
Published: November 2006

The performance of existing actuators, such as electric motors, is very limited, be it power–weight ratio or energy efficiency. In this paper, we discuss the method to design a practical walking machine under this severe constraint with focus on two concepts, the gravitationally decoupled actuation (GDA) and the coupled drive. The GDA decouples the driving system against the gravitational field to suppress generation of negative power and improve energy efficiency. On the other hand, the coupled drive couples the driving system to distribute the output power equally among actuators and maximize the utilization of installed actuator power. First, we depict the GDA and coupled drive in detail. Then, we present actual machines, TITAN-III and VIII, quadruped walking machines designed on the basis of the GDA, and NINJA-I and II, quadruped wall walking machines designed on the basis of the coupled drive. Finally, we discuss walking machines that travel on three-dimensional terrain (3D terrain), which includes the ground, walls and ceiling. Then, we demonstrate with computer simulation that we can selectively leverage GDA and coupled drive by walking posture control.
Control of stepping velocity in a single insect leg during walking
Authors: Gabriel Jens Peter , Büschges Ansgar
Published: November 2006

In the single middle leg preparation of the stick insect walking on a treadmill, the activity of flexor and extensor tibiae motor neurons and muscles, which are responsible for the movement of the tibia in stance and swing phases, respectively, was investigated with respect to changes in stepping velocity. Changes in stepping velocity were correlated with cycle period. There was a close correlation of flexor motor neuron activity (stance phase) with stepping velocity, but the duration and activation of extensor motor neurons (swing phase) was not altered. The depolarization of flexor motor neurons showed two components. At all step velocities, a stereotypic initial depolarization was generated at the beginning of stance phase activity. A subsequent larger depolarization and activation was tightly linked to belt velocity, i.e. it occurred earlier and with larger amplitude during fast steps compared with slow steps. Alterations in a tonic background excitation appear not to play a role in controlling the motor neuron activity for changes in stepping velocity. Our results indicate that in the single insect leg during walking, mechanisms for altering stepping velocity become effective only during an already ongoing stance phase motor output. We discuss the putative mechanisms involved.
Walking biped humanoids that perform manual labour
Authors: Hirukawa Hirohisa
Published: November 2006

The Humanoid Robotics Project of the Ministry of Economy, Trade and Industry of Japan realized that biped humanoid robots can perform manual labour. The project developed humanoid robot platforms, consisting of humanoid robot hardware and a package of fundamental software, and explored applications of humanoid robots on them. The applications include maintenance tasks of industrial plants, teleoperation of industrial vehicles, cooperative tasks with a human, guarding the home and office and the care of patients in beds.
The effect of assertive continuing care on continuing care linkage, adherence and abstinence following residential treatment for adolescents with substance use disorders
Authors: Godley Mark D. , Godley Susan H. , Dennis Michael L. , Funk Rodney R. , Passetti Lora L.
Published: November 2006

Aims  This study compared assertive continuing care (ACC) to usual continuing care (UCC) on linkage, retention and a measure of continuing care adherence. Outcome analyses tested the direct and indirect effects of both conditions and level of adherence on early (months 1–3) and longer‐term (months 4–9) abstinence.

Design  Two‐group randomized design.

Setting  Eleven counties surrounding a community‐based residential treatment program in the Midwestern section of the United States.

Participants  A total of 183 adolescents, ages 12–17 years, with one or more Diagnostic and Statistical Manual version IV (DSM‐IV) substance use dependence disorder and met American Society for Addiction Medicine (ASAM) placement criteria for non‐medical residential treatment.

Intervention  Prior to discharge from residential treatment, participants were assigned randomly to receive either UCC, available at outpatient clinics in the 11‐county study area, or ACC via home visits.

Measurements  Self‐reported interview data were collected at intake, 3, 6 and 9 months post‐residential discharge. Urine test data and interviews with a caregiver were conducted at baseline and 3 months.

Findings  ACC led to significantly greater continuing care linkage and retention and longer‐term abstinence from marijuana. ACC resulted in significantly better adherence to continuing care criteria which, in turn, predicted superior early abstinence. Superior early abstinence outcomes for both conditions predicted longer‐term abstinence.

Conclusions  ACC appears to be an effective alternative to UCC for linking, retaining and increasing adherence to continuing care. Replication with larger samples is needed to investigate further the direct and indirect effects of ACC found in this study.
UK smokers' and ex‐smokers' reactions to cigarettes promising reduced risk
Authors: Shiffman Saul , Jarvis Martin J. , Pillitteri Janine L. , Di Marino Michael E. , Gitchell Joe G. , Kemper Katherine E.
Published: November 2006

Aims This study evaluated the impact of exposure to information about a novel cigarette claiming to reduce exposure to tobacco toxins (‘potential reduced exposure product’ cigarette or PREP‐C) on smokers' and ex‐smokers' perceptions of PREP‐C, on quit interest among smokers and on interest in resuming smoking among ex‐smokers.

Design and Participants A random digit‐dialed telephone survey was conducted in the United Kingdom with 500 current smokers and 106 ex‐smokers who had quit within the last 2 years.

Intervention The interviewer described a novel cigarette that claimed to significantly reduce exposure to smoke toxins.

Measurements Respondents' interest in purchasing the PREP‐C, beliefs about its safety and risk reduction and smokers' quit interest, as measured by stage of change, before and after exposure to PREP‐C information.

Findings Among smokers, 76.5% were interested in purchasing PREP‐C; interest did not vary by stage of change. Almost all smokers (90.6%) thought PREP‐C was safer than regular cigarettes, with 5.4% indicating that the health risks were equivalent to not smoking at all. Exposure to PREP‐C description did not change quit interest. Among ex‐smokers, 5.6% believed PREP‐C carried no health risk and 7.1% expressed purchase interest.

Conclusions Smokers and ex‐smokers interpreted claims of reduced toxin exposure as reduced health risk and responded positively towards PREP‐Cs. With the increasing introduction of PREP‐Cs world‐wide, evaluation of these products and their claims on quitting among smokers and on relapse among ex‐smokers is a matter of public health urgency.
Methadone in pregnancy: treatment retention and neonatal outcomes
Authors: Burns Lucy , Mattick Richard P. , Lim Kim , Wallace Cate
Published: November 2006

Aim  To examine the association between retention in methadone treatment during pregnancy and key neonatal outcomes.

Design  Client data from the New South Wales Pharmaceutical Drugs of Addiction System was linked to birth information from the NSW Midwives Data Collection and the NSW Inpatient Statistics Collection from 1992 to 2002.

Measurements  Obstetric and perinatal characteristics of women who were retained continuously on methadone maintenance throughout their pregnancy were compared to those who entered late in their pregnancies (less than 6 months prior to birth) and those whose last treatment episode ended at least 1 year prior to birth.

Findings  There were 2993 births to women recorded as being on methadone at delivery, increasing from 62 in 1992 to 459 births in 2002. Compared to mothers who were maintained continuously on methadone throughout their pregnancy, those who entered treatment late also presented later to antenatal services, were more likely to arrive at hospital for delivery unbooked, were more often unmarried, indigenous and smoked more heavily. A higher proportion of neonates born to late entrants were born at less than 37 weeks gestation and were admitted to special care nursery more often.

Conclusion  Continuous methadone treatment during pregnancy is associated with earlier antenatal care and improved neonatal outcomes. Innovative techniques for early engagement in methadone treatment by pregnant heroin using women or those planning to become pregnant should be identified and implemented.
Adolescent passengers of drunk drivers: a multi‐level exploration into the inequities of risk and safety
Authors: Poulin Christiane , Boudreau Brock , Asbridge Mark
Published: November 2006

Aims  This study determined the individual‐, neighbourhood‐ and provincial‐level effects of rural residence, socio‐economic status (SES), substance use and driving behaviours on adolescents' riding with a drunk driver (RDD).

Design  Multi‐level study based on cross‐sectional self‐reported anonymous data from the Student Drug Use Survey in the Atlantic Provinces (SDUSAP) and Census Canada data, merged on the postal code of participating schools. The sample design of the SDUSAP was a single‐stage cluster sample of randomly selected classes stratified by grade and region.

Setting  The Atlantic provinces of Canada.

Participants  A total of 12 990 students in junior and senior high schools, with an average age of 15 years, participated in the 2002 SDUSAP.

Measurements  The outcome variable was past‐year RDD. The main individual‐level independent variables were SES, rural residence, substance use and driving behaviours. The school–neighbourhood independent variables were the prevalence of heavy episodic drinking, driving under the influence of alcohol, driver's licence, highest level of educational attainment and low income.

Findings  The prevalence of RDD was 23.3% in 2002. Among students in grades 9–12, lower family SES, rural residence, substance use and driving under the influence were found to be independent individual‐level risk factors for RDD; having a driver's licence was found to be protective. At the provincial and school–neighbourhood levels, a high prevalence of driving under the influence of alcohol and low educational attainment were found to be independent risk factors for RDD after taking into account individual characteristics.

Conclusions  This study provides evidence that inequities exist in the options for adolescents to be ensured of passenger safety, and that interventions aimed at decreasing the extent to which adolescents engage in riding with a drunk driver should be based on conceptual approaches that recognize ecological factors as well as individual‐level susceptibility.
IL-9 promotes anti-Mycobacterium lepraecytotoxicity: involvement of IFNγ
Authors: Finiasz M R , Franco M C , De La Barrera S , Rutitzky L , Pizzariello G , Del Carmen Sasiain M , Renauld J-C , Van Snick J , Fink S
Published: November 2006

Interleukin 9 (IL-9) is a T-cell derived factor preferentially expressed by CD4+ Th2 cells and it has been characterized both in human and murine systems. It is a pleiotropic cytokine with multiple functions on cells of the lymphoid, myeloid and mast cell lineages, as well as on lung epithelial cells. Other activities described for IL-9 support its contribution to asthma and its important role in helminthic infections, where a Th2 response can be protective and IL-9 enhances resistance or is responsible for elimination of the nematode. Nevertheless, until recently there were no studies on its role in bacterial infections in man. We have demonstrated that cytokines can modulate the specific cytotoxicity generation in peripheral blood mononuclear cells from leprosy patients and normal controls. In the present report we studied the effect of IL-9 in this experimental model. Our results indicate that IL-9 can counteract the negative effect mediated by IL-4 on the generation of M. leprae-induced cytotoxic T lymphocytes. Moreover, it can increase this lytic activity in controls and enhance the stimulatory effect of IL-2 or IL-6 in cells from leprosy patients and controls. IL-9 is also able to revert the inhibitory effect of IL-10 and IL-13 on the M. leprae-induced cytotoxic activity. Although the exact mechanism of action of IL-9 remains to be determined, interferon gamma seems to be required for the effect of IL-9 in this experimental model. These data suggest that IL-9 may have an atypical Th2 behaviour and play a role in the modulation of the immune response to mycobacterial infections.
Nicotine exposure altersin vivohuman responses to endotoxin
Authors: Wittebole X , Hahm S , Coyle S M , Kumar A , Calvano S E , Lowry S F
Published: November 2006

The alpha 7 nicotinic receptor is reportedly a key element in the cholinergic anti-inflammatory pathway. Because a prototypical ligand for this receptor is nicotine, we studied the in vivo human response to bacterial endotoxin or lipopolysaccharide (LPS) in the context of nicotine or placebo pretreatment. Twelve adult male normal subjects were studied prospectively. Six received overnight transcutaneous nicotine administration by application of a standard patch (7 mg). Six hours later, all subjects were given an intravenous dose of endotoxin (2 ng/kg) and were evaluated for an additional 24 h for circulating levels of inflammatory biomarkers, vital signs and symptoms. The nicotine subjects had elevated blood levels of the nicotine metabolite, continine, prior to and throughout the 24-h post-endotoxin exposure phase. Subjects receiving nicotine exhibited a significantly lower temperature response as well as attenuated cardiovascular responses for 2·5–6 h after LPS exposure. In addition, increased circulating interkeukin (IL)-10 and cortisol levels were also noted in nicotine subjects. These data indicate an alteration in LPS-induced systemic inflammatory responses in normal subjects exposed to transcutaneous nicotine. In this model of abbreviated inflammation, nicotine exposure attenuates the febrile response to LPS and promotes a more prominent anti-inflammatory phenotype.
Systemic inflammation alters the inflammatory response in experimental lipopolysaccharide-induced meningitis
Authors: O'Reilly T , Østergaard C , Vaxelaire J , Zak O
Published: November 2006

Experiments to evaluate the effect of the level and duration of endotoxaemia on the meningeal inflammatory response were performed in order to determine if systemic inflammation alters meningitis. Rabbits received either saline or Escherichia coli O111:B4 lipopolysacharide (LPS) intravenously at various doses (1, 3 or 10 µg) and times (−8, −2 or 0 h) before an intracisternal injection of 20 ng LPS. An intracisternal LPS injection together with saline intravenously produced a peak cerebrospinal fluid (CSF) tumour necrosis factor (TNF) level (95 ± 26 ng/ml) at 2 h and peak leucocyte level (5413 ± 764 cells/µl) at 4 h post-injection. Blood leucocytes were slightly elevated (12 000 ± 500/µl at 0 h; 16 900 ± 280/µl at 8 h) but plasma TNF was always undetectable (< 0·05 ng/ml). Conversely, intravenous injection of 3 or 10 µg LPS 2 h prior to intracisternal LPS injection impaired pleocytosis (peak < 220 cells/µl) and delayed (∼4 h) and reduced peak CSF TNF levels (3 µg LPS 5·0 ± 1·2 ng/ml; 10 µg LPS 6·9 ± 1·9; P < 0·05). Intravenous administration of 1 µg LPS was less inhibitory to CSF inflammation, but delayed onset (peak 1100 ± 60 leucocytes/µl CSF at 8 h; 6·3 ± 0·3 ng TNF/ml CSF at 4 h; both P < 0·05). Neutropenia nadirs were dependent on LPS dose (1 µg, 4500 ± 1700; 3 µg, 1900 ± 60; 10 µg, 1100 ± 100 all at 4 h post-intravenous dose). Peak plasma TNF levels were not dose-dependent (> 8 ng/ml), but plasma TNF was always detectable (> 0·2 ng/ml at 10 h post-intravenous dose). Intravenous LPS administration at 0 h also blocked pleocytosis, but the inhibitory effect was lost when administration at −8 h. In conclusion, the degree and duration of endotoxaemia affect the meningeal inflammatory response to LPS in experimental meningitis.
The emergence of the cortisol circadian rhythm in monozygotic and dizygotic twin infants: the twin‐pair synchrony
Authors: Custodio Rodrigo Jose , Junior Carlos Eduardo Martinelli , Milani Soraya Lopes Sader , Simões Aguinaldo Luis , De Castro Margaret , Moreira Ayrton Custodio
Published: November 2006

Objective  Studies on the influence of genetic factors on the ontogeny of cortisol circadian rhythm in infants are lacking. This study evaluated the influence of twinning and the heritability on the age of emergence of salivary cortisol rhythm.

Design and subjects  A longitudinal study was performed using salivary samples obtained during morning and night, at 2, 4, 8, 12, 16, 20 and 24 weeks of postnatal life in 34 infants, 10 monozygotic (MZ) and 7 dizygotic (DZ) twin pairs. Salivary cortisol was determined by radioimmunoassay (RIA). Zigosity was verified by DNA analysis of at least 13 short tandem repeat polymorphisms. Difference of the emergence of cortisol circadian rhythm, within each twin pair, the intraclass correlation coefficient and the heritability index (h2) were calculated.

Results  The mean (± SEM) age of emergence of salivary cortisol circadian rhythm was similar in MZ and DZ (7·8 ± 1·0 vs 7·4 ± 1·3 weeks). Seven pairs showed coincidence of the emergence of cortisol rhythm. Ten pairs were not coincident; among them the within‐pair difference of emergence of salivary circadian rhythm was similar in both MZ and DZ groups. The intraclass correlation coefficients were rMZ = 0·60, P = 0·02; and rDZ = 0·65, P = 0·03, respectively. The heritability index (h2) was 0·21 (ns).

Conclusions  Salivary circadian rhythm appeared at the same postnatal age in MZ and DZ twin infants. Although several physiological aspects might be involved, the heritability index, obtained in the present study, suggests less genetic than environmental impact on the age of the onset of the cortisol circadian rhythm. Our data also indicated that each twin‐pair show synchrony because they probably shared prenatal and postnatal environmental synchronizers.
Plant guilds drive biomass response to global warming and water availability in subalpine grassland
Authors: SEBASTIÀ MARIA‐TERESA
Published: November 2006

The consequences of global warming and changes in resource availability were investigated in subalpine grasslands in the Pyrenees. These communities are considered to be especially vulnerable to climate change because of their position at the south‐western edge of the semi‐natural grassland biome in Europe.

Changes in patterns of above‐ and below‐ground biomass were assessed for different plant guilds in two experiments, in which turves were transplanted from upland to lowland locations. The first experiment aimed to evaluate general responses to warming and drought, and the second to disentangle the effects of possible underlying mechanisms through resource manipulation by means of a nitrogen × phosphorus fertilization experiment.

The increased above‐ground biomass in grassland turves transplanted to lowlands suggested that biomass production was more temperature‐limited than water‐limited. The enhancement effect found in the upland turves following phosphorus addition supported the hypothesis of a strong limitation arising from reduced nutrient availability, confirming the central role played by phosphorus in these grasslands and its potential importance in the response to global change.

Nitrogen addition did not stimulate total biomass but affected guild composition. Grasses dominated the uplands and at high resource levels, while forbs dominated the lowlands and when water and nutrients decreased. The counterintuitive effect of increased biomass with decreased water in the lowlands was related to shifts in dominance from grasses to forbs, probably enabled by decreased nutrient availability under drought conditions.

Synthesis and applications. Environmental factors interacted in complex ways, producing changes in biomass distribution and guild proportions in subalpine grassland. In addition, the results suggested that the capability of high‐altitude grasslands to provide quality forage in summer time could be threatened in the northern Mediterranean region under climate change conditions because of: (i) a decrease in their reliability as a result of complex biomass interactions with temperature, water and nutrient dynamics; (ii) expected feedback mechanisms; and (iii) compositional shifts.
Local and landscape factors in differently managed arable fields affect the insect herbivore community of a non‐crop plant species
Authors: CLOUGH YANN , KRUESS ANDREAS , TSCHARNTKE TEJA
Published: November 2006

The expansion of simplified ecosystems such as intensively managed annual crops plays a big part in driving the global biodiversity crisis. Field‐scale diversification, for example leaving weeds to grow in crops, is one way in which diversity in agro‐ecosystems can be restored. However, little is known about the determinants of the non‐crop plant‐based insect communities within arable fields at local and larger spatial scales, an essential component in extrapolating plant diversity benefits to higher trophic levels.

We investigated how diversification of agro‐ecosystems at the field and landscape levels affects the insect community of the creeping thistle Cirsium arvense. Artificial plots of the host‐plant were established in three regions of Germany in 48 paired organic (diverse, weeds not controlled with herbicides) and conventional (simplified, very low weed density and species richness) wheat fields across a gradient of landscape heterogeneity, from simple arable‐dominated to heterogeneous, diverse landscapes.

Leaf‐feeding herbivores were monitored directly, while stem‐boring herbivores and their parasitoids were quantified by dissecting the stems of the thistles. Land‐use types and naturally occurring thistle stands were mapped within a radius of 1 km around each thistle plot.

Herbivore species richness was enhanced by both organic farming and landscape heterogeneity but not by higher densities of thistles in the landscape. For most of the species, host‐plant plots in organic fields were more likely to be colonized than those in the conventional fields. The enhancement of diversity in organic fields is probably the result of a slightly higher natural cover of the host‐plant Cirsium arvense.

Synthesis and applications. Both diversification of landscape (fewer arable crops, more perennial habitats) and extensification through organic management are effective measures of enhancing arthropod diversity on weeds. The impact of field‐scale agri‐environment schemes on biodiversity should be supplemented by including landscape‐scale diversification programmes to include a minimum level of perennial habitat cover. Biodiversity benefits of organic agriculture rely for a large part on non‐crop plants. Weed populations should be allowed to coexist with the crop to maintain these benefits, which are threatened by more intensive ‘organic’ management, such as heavy mechanical weed control.
Assessing impacts of large herbivores on shrubs: tests of scaling factors for utilization rates from shoot‐level measurements
Authors: BILYEU DANIELLE M. , COOPER DAVID J. , HOBBS N. THOMPSON
Published: November 2006

Accurate methods for estimating the intensity of browsing by herbivores are fundamental to understanding the ecology of shrub communities. Quantifying browse utilization on shrubs at large scales is difficult because shrubs have complex, spatially variable growth forms. Most existing methods estimate browsing rate at the scale of linear current‐year shoots or twigs. How such fine‐scale estimates relate to the proportion of current‐year growth consumed from whole plants or plots is often unknown. The relationship is likely to be complex because herbivores selectively browse more productive plants and plant parts.

Using a clipping experiment designed to mimic elk Cervus elaphus browsing, we quantified how utilization estimates at the scale of individual current‐year shoots of two willow species, Salix bebbiana and Salix geyeriana, relate to actual mass removed at the scale of rooted stems. Three approaches to scaling were examined: (i) taking an average, (ii) multiplying by the proportion of shoots clipped and (iii) multiplying by a novel scaling factor that weights utilization by productivity. To address how to scale‐up from stems to plots, we applied the most accurate stem‐level method to elk‐browsed willow and compared plot‐level estimates by two scaling approaches.

In scaling from shoots to stems, the novel scaling factor was most successful and resulted in accurate estimates for up to c. 45% of current annual growth clipped. In scaling from the stem to the plot, elk preference for more productive stems caused a simple average of stem‐level utilization to differ from a productivity‐weighted average by 15%.

Synthesis and applications. In order to reflect accurately the proportion of biomass consumed at a whole‐plant level, fine‐scale estimates of utilization should be weighted by an estimate of pre‐browse productivity, as this is mathematically equivalent to summing pre‐browse and post‐browse mass before calculating the proportion consumed. In developing methods to estimate utilization at plot scales, an important consideration is the choice of sampling unit, which should be both amenable to unbiased sampling and tractable in terms of measuring productivity.
Altered Expression of SOCS3 in the Hypothalamic Arcuate Nucleus during Seasonal Body Mass Changes in the Field Vole,Microtus agrestis
Authors: Król E. , Tups A. , Archer Z. A. , Ross A. W. , Moar K. M. , Bell L. M. , Duncan J. S. , Mayer C. , Morgan P. J. , Mercer J. G. , Speakman J. R.
Published: November 2006

We have previously shown that cold‐acclimated (8 °C) male field voles (Microtus agrestis) transferred from short day (SD, 8 h light) to long day (LD, 16 h light) photoperiod exhibit an increase in body mass lasting 4 weeks, after which they stabilise at a new plateau approximately 7.5 g (24.8%) higher than animals maintained in SD. By infusing voles with exogenous leptin, we have also demonstrated that SD voles respond to the hormone by reducing body mass and food intake, whereas LD animals increasing body mass are resistant to leptin treatment. In the present study, we investigated whether seasonal changes in body mass could be linked to modulation of the leptin signal by suppressor of cytokine signalling‐3 (SOCS3). We usedin situhybridisation to examine hypothalamic arcuate nucleus (ARC) expression of SOCS3, neuropeptide Y (NPY), agouti‐related peptide (AgRP), pro‐opiomelanocortin (POMC) and cocaine‐ and amphetamine‐regulated transcript (CART) genes in 90 voles exposed to either SD or LD for up to 11 weeks. LD voles increasing body mass had significantly higher levels of SOCS3 mRNA than SD or LD voles with a stable body mass. There were no associated changes in expression of NPY, AgRP, POMC and CART genes. These results suggest that voles that regulate body mass at either the lower (SD) or upper (LD) plateau remain sensitive to leptin action, whereas SOCS3‐mediated leptin resistance is a short‐term mechanism that enables animals to move between the stable body mass plateaus. Our data provide evidence that expression of SOCS3 in the ARC is involved in the modulation of the strength of the leptin signal to facilitate seasonal cycles in body mass and adiposity.
Developmental regulation of the glyoxylate cycle in the human pathogen Penicillium marneffei
Authors: Cánovas David , Andrianopoulos Alex
Published: November 2006

Penicillium marneffei is a thermally dimorphic opportunistic human pathogen with a saprophytic filamentous hyphal form at 25°C and a pathogenic unicellular yeast form at 37°C. During infection. P. marneffei yeast cells exist intracellularly in macrophages. To cope with nutrient deprivation during the infection process, a number of pathogens employ the glyoxylate cycle to utilize fatty acids as carbon sources. The genes which constitute this pathway have been implicated in pathogenesis. To investigate acetate and fatty acid utilization, the acuD gene encoding a key glyoxylate cycle enzyme (isocitrate lyase) was cloned. The acuD gene is regulated by both carbon source and temperature in P. marneffei, being strongly induced at 37°C even in the presence of a repressing carbon source such as glucose. When introduced into the non‐pathogenic monomorphic fungus Aspergillus nidulans, the P. marneffei acuD promoter only responds to carbon source. Similarly, when the A. nidulans acuD promoter is introduced into P. marneffei it only responds to carbon source suggesting that P. marneffei possesses both cis elements and trans‐acting factors to control acuD by temperature. The Zn(II)2Cys6 DNA binding motif transcriptional activator FacB was cloned and is responsible for carbon source‐, but not temperature‐, dependent induction of acuD. The expression of acuD at 37°C is induced by AbaA, a key regulator of morphogenesis in P. marneffei, but deletion of abaA does not completely eliminate temperature‐dependent induction, suggesting that acuD and the glyoxylate cycle are regulated by a complex network of factors in P. marneffei which may contribute to its pathogenicity.
Hypermutagenesis in mutA cells is mediated by mistranslational corruption of polymerase, and is accompanied by replication fork collapse
Authors: Al Mamun Abu Amar M. , Gautam Satyendra , Humayun M. Zafri
Published: November 2006

Elevated mistranslation induces a mutator response termed translational stress‐induced mutagenesis (TSM) that is mediated by an unidentified modification of DNA polymerase III. Here we address two questions: (i) does TSM result from direct polymerase corruption, or from an indirect pathway triggered by increased protein turnover? (ii) Why are homologous recombination functions required for the expression of TSM under certain conditions, but not others? We show that replication of bacteriophage T4 in cells expressing the mutA allele of the glyV tRNA gene (Asp→Gly mistranslation), leads to both increased mutagenesis, and to an altered mutational specificity, results that strongly support mistranslational corruption of DNA polymerase. We also show that expression of mutA, which confers a recA‐dependent mutator phenotype, leads to increased lambdoid prophage induction (selectable in vivo expression technology assay), suggesting that replication fork collapse occurs more frequently in mutA cells relative to control cells. No such increase in prophage induction is seen in cells expressing alaVGlu tRNA (Glu→Ala mistranslation), in which the mutator phenotype is recA‐independent. We propose that replication fork collapse accompanies episodic hypermutagenic replication cycles in mutA cells, requiring homologous recombination functions for fork recovery, and therefore, for mutation recovery. These findings highlight hitherto under‐appreciated links among translation, replication and recombination, and suggest that translational fidelity, which is affected by genetic and environmental signals, is a key modulator of replication fidelity.
Achilles tendon imaging
Authors: Harris CA , Peduto AJ
Published: November 2006

The Achilles tendon is the largest and strongest tendon in the body, yet one of the most commonly injured. Tendon degeneration is a relatively common disorder, predisposing to tears and often associated with paratenonitis. Numerous other diseases involve the Achilles tendon, some with classic imaging appearances, others with non‐specific appearances. The aim of this pictorial essay is to review the radiographic, computed tomographic, ultrasonographic and MR appearances of the normal and diseased Achilles tendon.
Familial cerebral cavernous haemangioma diagnosed in an infant with a rapidly growing cerebral lesion
Authors: Ng BHK , Mulyadi E , Pereira JK , Ghedia S , Pinner J , Mowat D , Vonau M
Published: November 2006

Cavernous haemangiomas of the central nervous system are vascular malformations best imaged by MRI. They may present at any age, but to our knowledge only 39 cases in the first year of life have previously been reported. A familial form has been described and some of the underlying genetic mutations have recently been discovered. We present the clinical features and serial MRI findings of an 8‐week‐old boy who presented with subacute intracranial haemorrhage followed by rapid growth of a surgically proven cavernous haemangioma, mimicking a tumour. He also developed new lesions. A strong family history of neurological disease was elucidated. A familial form of cavernous haemangioma was confirmed by identification of a KRIT 1 gene mutation and cavernous haemangiomas in the patient and other family members. We stress the importance of considering cavernous haemangiomas in the context of intracerebral haemorrhage and in the differential diagnosis of rapidly growing lesions in this age group. The family history is also important in screening for familial disease.
Long‐standing Morel‐Lavallée lesion in the proximal thigh: Ultrasound and MR findings with surgical and histopathological correlation
Authors: Puig J , Pelaez I , Baños J , Balliu E , Casas M , Maroto A , Pedraza S
Published: November 2006

A 65‐year‐old man presented with a soft mass in his proximal right thigh. Ultrasonography showed a well‐defined anechoic lesion with slightly internal echoes. On MRI, the mass was hypointense and minimally hyperintense compared with muscle at T1 and hyperintense at T2, with a hypointense peripheral rim on both sequences. No signal loss was observed on T1‐weighted fat‐suppression MRI. The clinical setting, imaging findings and histopathological features were consistent with a long‐standing Morel‐Lavallée lesion.
Midline septa in the lumbo‐sacral thecal sac: Acquired abnormality or developmental anomaly? The equivalent of diastematomyelia occurring below the spinal cord?
Authors: Roche J. , Vignaendra D.
Published: November 2006

Careful analysis of over 400 patients radiologically diagnosed with arachnoiditis showed a subgroup of eight patients with a specific set of imaging signs that suggest a pre‐existing developmental abnormality mimicking the appearance of arachnoiditis. These cases have been collected over a 15‐year period. No autopsy or surgical proof is available. All patients have (i) the presence of a well‐defined midline septum in the sagittal plane that splits the thecal sac, usually symmetrically, in the lower lumbar or sacral region, below the level of the spinal cord; (ii) the absence of adjacent epidural fibrosis that one would expect if the septation had been caused by surgical intervention or trauma; (iii) the preservation of cerebrospinal fluid within the nerve root sheaths and around the nerve roots at the level of the septation; and in four cases (iv) the presence of either calcification or bone in this midline septum, yet nowhere else in the theca or epidural space. These cases suggest a developmental variant called, for want of a better term, ‘split lumbo‐sacral thecal sac’ analogous to diastematomyelia but not involving the spinal cord. This variant is potentially confused with arachnoiditis or thecal scarring in the lumbo‐sacral sac.
Sarcomatoid renal cell carcinoma: Rapid dissemination detected on FDG PET‐CT
Authors: Thambugala GM , Mohamed A , O’ Neill GFA , Fulham MJ
Published: November 2006

We present the FDG PET‐CT findings in a patient with persistent pain 7 weeks after a nephrectomy and lymph node dissection for a sarcomatoid renal cell carcinoma. Although conventional imaging was unable to detect evidence of metastatic spread outside the para‐aortic nodes, a PET‐CT scan showed unexpected extensive dissemination. Currently, there are no reports in the literature of the PET‐CT findings in sarcomatoid renal cell carcinomas.
Phonological but not auditory discrimination is impaired in dyslexia
Authors: Paul Isabella , Bott Christof , Heim Sabine , Wienbruch Christian , Elbert Thomas R.
Published: November 2006

Deficient phonological skills are considered to be a core problem in developmental dyslexia. Children with dyslexia often demonstrate poorer performance than non‐impaired readers when categorizing speech‐sounds. Using the automatic mismatch response, we show that in contrast to this deficit at the behavioural level, neurophysiological responding in dyslexic children indicates their ability to automatically discriminate syllables. Therefore, the phonological deficit is unlikely to be caused by a temporal deficit or by a noisy functional organization in the respective representational cortex. We obtained measures of reading, spelling and categorical speech‐perception from 58 dyslexic children and 21 control children. The children also participated in magnetoencephalographic measurements while being stimulated acoustically with the syllables /ba/ and /da/ in an oddball paradigm. Mismatch field (MMF) amplitudes between standard and deviant stimuli were obtained. Dyslexic children performed more poorly than control children on all test measures. However, the groups did not differ in MMF amplitude or latency. No correlations were found between MMF amplitudes and behavioural performance.

These results were obtained with a large sample size and thus speak robustly against a general deficit in auditory discrimination in dyslexia. These results are compatible with the idea that decoding difficulties occur later in the processing stream where access to the phonological lexicon is attempted.
Relationship between the perifornical hypothalamic area and oral pontine reticular nucleus in the rat. Possible implication of the hypocretinergic projection in the control of rapid eye movement sleep
Authors: Nuñez A. , Moreno‐Balandrán M. E. , Rodrigo‐Angulo M. L. , Garzón M. , De Andrés I.
Published: November 2006

The perifornical (PeF) area in the posterior lateral hypothalamus has been implicated in several physiological functions including the regulation of sleep–wakefulness. Some PeF neurons, which contain hypocretin, have been suggested to play an important role in sleep–wake regulation. The aim of the present study was to examine the effect of the PeF area and hypocretin on the electrophysiological activity of neurons of the oral pontine reticular nucleus (PnO), which is an important structure in the generation and maintenance of rapid eye movement sleep. PnO neurons were recorded in urethane‐anesthetized rats. Extracellular recordings were performed by means of tungsten microelectrodes or barrel micropipettes. Electrical stimulation of the ipsilateral PeF area elicited orthodromic responses in both type I (49%) and type II (58%) electrophysiologically characterized PnO neurons, with a mean latency of 13.0 ± 2 and 8.3 ± 5 ms, respectively. In six cases, antidromic spikes were evoked in type I PnO neurons with a mean latency of 3.2 ± 0.4 ms, indicating the existence of PnO neurons that projected to the PeF area. Anatomical studies showed retrogradely labeled neurons in the PeF area from the PnO. Some of these neurons projecting to the PnO contained hypocretin (17.8%). Iontophoretic application of hypocretin‐1 through a barrel micropipette in the PnO induced an inhibition, which was blocked by a previous iontophoretic application of bicuculline, indicating that the inhibitory action of hypocretin‐1 may be due to activation of GABAA receptors. These data suggest that the PeF area may control the generation of rapid eye movement sleep through a hypocretinergic projection by inhibiting the activity of PnO neurons.
An evaluation of the filtration performance of paediatric breathing system filters using sodium chloride particles at low flows
Authors: Malan C.A. , Wilkes A.R. , Gildersleve C.
Published: November 2006

Introduction:  A minimum standard has yet to be set for paediatric breathing system filters. An evaluation of adult, paediatric and neonatal filters suggested that paediatric filters may have greater penetrance than adult filters at preset flows (1). Hence, it has been suggested that paediatric filters may be less efficient in the prevention of transmission of infective agents (2). While evaluations have been carried out at flows set by the British Standards Institution (3), concern has been expressed that these are not representative of the flows encountered in clinical practice. The use of more appropriate flows would allow the development of more reliable performance criteria. This study evaluated the pressure drop and penetrance of five filters at flows of 3 and 15 l·min‐1.

Methods:  The pressure drop across 15 unused samples of five different filters was measured at a flow of 15 l·min‐1 (RT‐200 Calibration Analyser, Timeter Corp, St Louis, USA). The penetration of sodium chloride particles through five samples of each filter was measured at a flow of 15 l·min‐1 using a ‘Moore's’ Test Rig (CEN Bench Rig, SFP Services, Christchurch, UK) (2). Subsequently, two groups of five of the same filters were tested in parallel using a flow of 15 l·min‐1, thus each filter was tested at a flow of 3 l·min‐1.

Results: 

Filter type
Pressure drop at 15 l·min‐1 (cmH2O)
Penetrance (%)

15 l·min‐1
Parallel testing, equivalent to 3 l·min‐1

1st group
2nd group

Hygroboy
1.3 (0.2)
1.9 (1.8–3.5)
0.3
0.2

Air safety MIDI
2.7 (0.9)
2.8 (2.4–2.9)
0.2
0.2

Intersurgical
1.9 (0.1)
3.2 (2.9–4.3)
0.4
0.4

Hygrobaby
3.0 (0.3)
3.0 (2.9–4.3)
0.6
0.4

Air safety Neonatal
1.4 (0.1)
10.3 (7.5–12.3)
1.8
1.6

Data are mean (SD) or median (range)

Discussion and Conclusions:  The filtration performance of paediatric filters when tested using sodium chloride particles and a gas flow of 3.l min‐1 is more efficient compared to their performance when tested at a gas flow of 15 l·min‐1. Coughing through a filter will produce much higher flows, at which the filters have yet to be evaluated. A minimum standard of performance is yet to be established for paediatric breathing system filters.

References  1 Wilkes AR. An assessment of 104 breathing system filters. London: Medicines and Healthcare products Regulatory Agency. Evaluation 04005. March 2004.

2 Bennett N, Bingham R. Association of Paediatric Anaesthetists of Great Britain and Ireland. Statement on Paediatric Filters and Breathing Systems. January 2005.

3 British Standards Institution. Breathing system filters for anaesthetic and respiratory use – Part I: salt test method to assess filtration performance (BS EN 13328‐1:2001). Milton Keynes, UK: British Standards Institution, 2001.
Prone equals prone? – impact of different techniques of body positioning on functional residual capacity and ventilation distribution in anaesthetised, paralysed preschool children
Authors: Von Ungern‐Sternberg B.S. , Frei F.J. , Hammer J. , Erb T.O.
Published: November 2006

Introduction:  In children undergoing anesthesia or sedation, optimizing functional residual capacity (FRC) is of special importance, because they have smaller elastic retraction forces compared with adults and a lower relaxation volume that makes them more prone to airway collapse. Moreover, children are particularly vulnerable to hypoxaemia because of their higher oxygen demand per kilo body weight. Although the prone position is effectively used to improve oxygenation, its impact on FRC is controversial. Thus, additional confounding factors such as changes in ventilation distribution or differences in positioning techniques might be of importance. In fact, positioning techniques such as flat versus augmented prone position could exert different degrees of pressure on the abdominal contents and thus differences in the cephalic displacement of the diaphragm. The aim of this study was to determine the impact of two different prone positioning techniques on FRC and ventilation distribution in anesthetized, paralyzed preschool‐aged children. We hypothesized that augmented prone positioning improves FRC and ventilation distribution compared with the supine or flat prone position.

Methods:  Following local Ethics Committee approval, 30 preschool children without cardiopulmonary disease undergoing elective surgery were studied. FRC and lung clearance index (LCI), a measure of ventilation distribution, were calculated using a sulfur‐hexafluoride gas (SF6) multibreath washout technique. After intubation, the measurements were taken in the supine position and in random order in the flat prone and augmented prone position (gel pads supporting the pelvis and the upper thorax to ensure free movement of the abdomen). The position of the arms was kept constant and the head was turned to the side for all assessments. Measurements were taken 5 min after each positioning.

Results:  Mean (range) age was 48.5 (24–80) months, weight = 17.2 (10.5–26.9) kg. FRC (mean ± SD) was 22.9 ± 6.2 ml·kg‐1 in the supine position and 23.3 ± 5.6 ml·kg‐1 in the flat prone position while LCI was 8.1 ± 2.3 vs 7.9 ± 2.3 in these two positions, respectively. In contrast, FRC increased to 27.6 ± 6.5 ml·kg‐1 (P < 0.001) in the augmented prone position while at the same time the LCI decreased to 6.7 ± 0.9 (P < 0.001).

Conclusions:  FRC and ventilation distribution were similar in the supine and flat prone positions, while these parameters improved significantly in the augmented prone position suggesting that the technique of prone positioning could have a major impact on respiratory function in anaesthetized, mechanically ventilated preschool children.

Acknowledgement:  The study was funded by the Department of Anaesthesia, University of Basel, Switzerland.