bluuebunny/crossref_metadata_2025 huggingface dataset:
Learning networks for schools: keeping up with the times or a leap into the unknown?
Authors: O'Brien Mark , Burton Diana , Campbell Anne , Qualter Anne , Varga‐Atkins Tünde
Published: December 2006

This article seeks to explore the ‘fit’ of ‘the network’ as an organizational form being implemented in schools in England. It considers current trends within education policy, pedagogy and educational technology in the context of these new service delivery models and relates these to the current interest in learning networks. The article draws upon the experience of school networks as it has been discussed in evaluation research and literature surveys, to highlight the issues around their implementation. The purpose, typology and potential tensions of educational networks are reviewed, with a particular focus on the Networked Learning Communities (NLCs) pioneered by the National College for School Leadership (NCSL). Although, on the face of things, the position of the ‘school network’ as a structural model seems logical, there are significant tensions which suggest that the implementation and development of meaningful and high quality networks is far more challenging than the government may appreciate.
Microfabrication technologies for a coupled three-dimensional microelectrode, microfluidic array
Authors: Rajaraman Swaminathan , Choi Seong-O , Shafer Richard H , Ross James D , Vukasinovic Jelena , Choi Yoonsu , DeWeerth Stephen P , Glezer Ari , Allen Mark G
Published: December 2006

Planar or two-dimensional (2D) microelectrode arrays (MEAs), which are used forin vitroculturing of neurons and tissue slices, have been in existence for over 30 years. However, in order to study complex network morphologies and tissue slices which contain substantial 3D neuronal structures, 3D MEAs with microfluidic ports are required. Integrated fabrication of 3D MEAs with embedded microfluidic ports for nutrient perfusion through these relatively thick tissues typically requires non-planar lithography, which is not easily accomplished. This paper reports a laser-scribing technique coupled with electroplating to fabricate 3D MEAs coupled with microfluidic ports. An excimer laser has been used to define patterns in a polymer mold layer that is conformally vapor-deposited on a 3D microfluidic SU-8 substrate. Metal is electroplated through this mold to fabricate electrodes at multiple heights. To demonstrate 3D MEAs, a standard design was chosen consisting of an array of three-dimensional protrusions (‘towers’) optionally with microfluidic functionality on which electrodes can be formed extending to the top of each tower. Additional electrodes are formed on the substrate resulting in a multi-level electrode structure. Since microfluidics can exist both in the substrate as well as along the towers, a coupled three-dimensional electrical and microfluidic functionality is achieved. The resulting 3D MEAs have been analyzed electrically using impedance spectroscopy and baseline noise measurements. They have further been evaluated fluidically using micro-particle image velocimetry measurements.
Feeding mechanics and bite force modelling of the skull ofDunkleosteus terrelli, an ancient apex predator
Authors: Anderson Philip S.L , Westneat Mark W
Published: December 2006

Placoderms are a diverse group of armoured fishes that dominated the aquatic ecosystems of the Devonian Period, 415–360 million years ago. The bladed jaws of predators such asDunkleosteussuggest that these animals were the first vertebrates to use rapid mouth opening and a powerful bite to capture and fragment evasive prey items prior to ingestion. Here, we develop a biomechanical model of force and motion during feeding inDunkleosteus terrellithat reveals a highly kinetic skull driven by a unique four-bar linkage mechanism. The linkage system has a high-speed transmission for jaw opening, producing a rapid expansion phase similar to modern fishes that use suction during prey capture. Jaw closing muscles power an extraordinarily strong bite, with an estimated maximal bite force of over 4400 N at the jaw tip and more than 5300 N at the rear dental plates, for a large individual (6 m in total length). This bite force capability is the greatest of all living or fossil fishes and is among the most powerful bites in animals.
Spatial genetic analysis and long-term mark–recapture data demonstrate male-biased dispersal in a snake
Authors: Keogh J. Scott , Webb Jonathan K , Shine Richard
Published: December 2006

Dispersal is an important life-history trait, but it is notoriously difficult to study. The most powerful approach is to attack the problem with multiple independent sources of data. We integrated information from a 14-year demographic study with molecular data from five polymorphic microsatellite loci to test the prediction of male-biased dispersal in a common elapid species from eastern Australia, the small-eyed snakeRhinoplocephalus nigrescens. These snakes have a polygynous mating system in which males fight for access to females. Our demographic data demonstrate that males move farther than females (about twice as far on average, and about three times for maximum distances). This sex bias in adult dispersal was evident also in the genetic data, which showed a strong and significant genetic signature of male-biased dispersal. Together, the genetic and demographic data suggest that gene flow is largely mediated by males in this species.
The adaptive significance of ontogenetic colour change in a tropical python
Authors: Wilson David , Heinsohn Robert , Endler John A
Published: December 2006

Ontogenetic colour change is typically associated with changes in size, vulnerability or habitat, but assessment of its functional significance requires quantification of the colour signals from the receivers' perspective. The tropical python,
Morelia viridis
, is an ideal species to establish the functional significance of ontogenetic colour change. Neonates hatch either yellow or red and both the morphs change to green with age. Here, we show that colour change from red or yellow to green provides camouflage from visually oriented avian predators in the different habitats used by juveniles and adults. This reflects changes in foraging behaviour and vulnerability as individuals mature and provides a rare demonstration of the adaptive value of ontogenetic colour change.
Interspecific transmission of endosymbiotic
Spiroplasma
by mites
Authors: Jaenike John , Polak Michal , Fiskin Anna , Helou Mada , Minhas Miranda
Published: December 2006

The occurrence of closely related strains of maternally transmitted endosymbionts in distantly related insect species indicates that these infections can colonize new host species by lateral transfer, although the mechanisms by which this occurs are unknown. We investigated whether ectoparasitic mites, which feed on insect haemolymph, can serve as interspecific vectors of
Spiroplasma poulsonii
, a male-killing endosymbiont of
Drosophila
. Using
Spiroplasma
-specific primers for PCR, we found that mites can pick up
Spiroplasma
from infected
Drosophila nebulosa
females and subsequently transfer the infection to
Drosophila willistoni
. Some of the progeny of the recipient
D. willistoni
were infected, indicating successful maternal transmission of the
Spiroplasma
within the new host species. However, the transmission rate of the infection from recipient flies to their offspring was low, perhaps due to low
Spiroplasma
density in the recipient flies.
Utility ofR0as a predictor of disease invasion in structured populations
Authors: Cross Paul C , Johnson Philip L.F , Lloyd-Smith James O , Getz Wayne M
Published: December 2006

Early theoretical work on disease invasion typically assumed large and well-mixed host populations. Many human and wildlife systems, however, have small groups with limited movement among groups. In these situations, the basic reproductive number,R0, is likely to be a poor predictor of a disease pandemic because it typically does not account for group structure and movement of individuals among groups. We extend recent work by combining the movement of hosts, transmission within groups, recovery from infection and the recruitment of new susceptibles into a stochastic model of disease in a host metapopulation. We focus on how recruitment of susceptibles affects disease invasion and how population structure can affect the frequency of superspreading events (SSEs). We show that the frequency of SSEs may decrease with the reduced movement and the group sizes due to the limited number of susceptible individuals available. Classification tree analysis of the model results illustrates the hierarchical nature of disease invasion in host metapopulations. First, the pathogen must effectively transmit within a group (R0>1), and then the pathogen must persist within a group long enough to allow for movement among the groups. Therefore, the factors affecting disease persistence—such as infectious period, group size and recruitment of new susceptibles—are as important as the local transmission rates in predicting the spread of pathogens across a metapopulation.
The role of maternal antibodies in the emergence of severe disease as a result of fragmentation
Authors: Fouchet David , Marchandeau Stéphane , Bahi-Jaber Nargès , Pontier Dominique
Published: December 2006

Population fragmentation is a major problem for the conservation of mammalian species. Since the spread of an infectious disease is related to the intensity of contacts between individuals, fragmentation destabilizes the way the parasites circulate in their host population. Recently, Zinkernagel has proposed that a reduction in the frequency of infections by a parasite could lead to the emergence of severe forms of the disease, previously avoided because the disease was contracted early in life and attenuated by maternal antibodies. However, it is still unclear whether this change in disease expression increases the global mortality it induces because the disease becomes more severe and also less frequent. Here, we use a mathematical model to link population fragmentation with the hypothesis of Zinkernagel. Firstly, we show that there is a change in the severity of the disease during the fragmentation process, especially at a local scale, suggesting that host population fragmentation could be a widespread mechanism of disease emergence. Secondly, we show that the emergence of the severe form of the disease can lead to a significant increase in its induced mortality. Finally, we determine the types of interactions for which the fragmentation of the host population could be the most dangerous.
The influence of surface lubricity on the adhesion of
Navicula perminuta
and
Ulva linza
to alkanethiol self-assembled monolayers
Authors: Bowen J , Pettitt M.E , Kendall K , Leggett G.J , Preece J.A , Callow M.E , Callow J.A
Published: December 2006

The settlement and adhesion of
Navicula perminuta
and
Ulva linza
to methyl-terminated alkanethiol self-assembled monolayers (SAMs) of increasing chain length has been investigated. Organisms were allowed to settle onto the monolayers and were subsequently exposed to hydrodynamic shear stress in order to determine their adhesion strength. Results show that as the SAM structure changes from amorphous to crystalline (C14), there is a marked change in the adhesion of
N. perminuta
and
U. linza
. Given that the SAMs in the series all exhibit similar contact angle behaviour and surface energy, it is hypothesized that the lubricity of the surface plays a role in determining the surface adhesion.
Significance of temporal and spectral acoustic cues for sexual recognition inXenopus laevis
Authors: Vignal Clémentine , Kelley Darcy
Published: December 2006

As in many anurans, males of the totally aquatic species,Xenopus laevis, advertise their sexual receptivity using vocalizations. Unusually for anurans,X. laevisfemales also advertise producing a fertility call that results in courtship duets between partners. Although allX. laeviscalls consist of repetitive click trains, male and female calls exhibit sex-specific acoustic features that might convey sexual identity. We tested the significance of the carrier frequency and the temporal pattern of calls using underwater playback experiments in which modified calls were used to evoke vocal responses in males. Since males respond differently to male and female calls, the modification of a key component of sexual identity in calls should change the male's response. We found that a female-like slow call rhythm triggers more vocal activity than a male-like fast rhythm. A call containing both a female-like temporal pattern and a female-like carrier frequency elicits higher levels of courtship display than either feature alone. In contrast, a male-like temporal pattern is sufficient to trigger typical male–male encounter vocalizations regardless of spectral cues. Thus, our evidence supports a role for temporal acoustic cues in sexual identity recognition and for spectral acoustic cues in conveying female attractiveness inX. laevis.
Marine pelagic ecosystems: the West Antarctic Peninsula
Authors: Ducklow Hugh W , Baker Karen , Martinson Douglas G , Quetin Langdon B , Ross Robin M , Smith Raymond C , Stammerjohn Sharon E , Vernet Maria , Fraser William
Published: December 2006

The marine ecosystem of the West Antarctic Peninsula (WAP) extends from the Bellingshausen Sea to the northern tip of the peninsula and from the mostly glaciated coast across the continental shelf to the shelf break in the west. The glacially sculpted coastline along the peninsula is highly convoluted and characterized by deep embayments that are often interconnected by channels that facilitate transport of heat and nutrients into the shelf domain. The ecosystem is divided into three subregions, the continental slope, shelf and coastal regions, each with unique ocean dynamics, water mass and biological distributions. The WAP shelf lies within the Antarctic Sea Ice Zone (SIZ) and like other SIZs, the WAP system is very productive, supporting large stocks of marine mammals, birds and the Antarctic krill,Euphausia superba. Ecosystem dynamics is dominated by the seasonal and interannual variation in sea ice extent and retreat. The Antarctic Peninsula is one among the most rapidly warming regions on Earth, having experienced a 2°C increase in the annual mean temperature and a 6°C rise in the mean winter temperature since 1950. Delivery of heat from the Antarctic Circumpolar Current has increased significantly in the past decade, sufficient to drive to a 0.6°C warming of the upper 300 m of shelf water. In the past 50 years and continuing in the twenty-first century, the warm, moist maritime climate of the northern WAP has been migrating south, displacing the once dominant cold, dry continental Antarctic climate and causing multi-level responses in the marine ecosystem. Ecosystem responses to the regional warming include increased heat transport, decreased sea ice extent and duration, local declines in ice-dependent Adélie penguins, increase in ice-tolerant gentoo and chinstrap penguins, alterations in phytoplankton and zooplankton community composition and changes in krill recruitment, abundance and availability to predators. The climate/ecological gradients extending along the WAP and the presence of monitoring systems, field stations and long-term research programmes make the region an invaluable observatory of climate change and marine ecosystem response.
Integrating stream bioassessment and landscape ecology as a tool for land use planning
Authors: BAILEY ROBERT C. , REYNOLDSON TREFOR B. , YATES ADAM G. , BAILEY JOHN , LINKE SIMON
Published: December 2006

1. Bioassessment has evolved significantly from a method of deciding whether an ecosystem exposed to stressors should ‘pass’ or ‘fail’ (or how badly it fails). Society wants some notion of what has caused any observed degradation of ecosystems, and what management strategies might improve degraded ecosystems. Managers also want to predict what negative or positive effects different land use strategies will have on the component ecosystems of a landscape, including lakes and streams.

2. Here we illustrate an approach to providing these tools to managers with data from a bioassessment study of streams in the Fraser River Basin of British Columbia, Canada.

3. Landscape scale descriptors of both the natural (e.g. catchment size, surficial geology) and stressor (e.g. hard rock mines, forest harvest) environment of each site were used to define the natural and stressor environments of each of the 242 stream sites.

4. We classified 206 reference (relatively unexposed to human activity) sites using their benthic macroinvertebrate community composition, and then discriminated among the faunally defined groups with landscape scale descriptors of the natural environment of the sites.

5. This discriminant function model allowed us to predict which group each of the test sites would be in if it were in reference condition, and then measure the relationship between the amount of human activity and the biota in each of these groups.

6. These relationships were turned into projections of what will happen to a stream ecosystem's biota if the stressor environment is either improved or degraded. These projection models form the basis of evidence‐based land use planning that takes into account the health of freshwater ecosystems.
Tobacco zygotic embryogenesis in vitro: the original cell wall of the zygote is essential for maintenance of cell polarity, the apical–basal axis and typical suspensor formation
Authors: He Yu‐Chi , He Yu‐Qing , Qu Liang‐Huan , Sun Meng‐Xiang , Yang Hong‐Yuan
Published: December 2006

We have developed a reliable in vitro zygotic embryogenesis system in tobacco. A single zygote of a dicotyledonous plant was able to develop into a fertile plant via direct embryogenesis with the aid of a co‐culture system in which fertilized ovules were employed as feeders. The results confirmed that a tobacco zygote could divide in vitro following the basic embryogenic pattern of the Solanad type. The zygote cell wall and directional expansion are two critical points in maintaining apical–basal polarity and determining the developmental fate of the zygote. Only those isolated zygotes with an almost intact original cell wall could continue limited directional expansion in vitro, and only these directionally expanded zygotes could divide into typical apical and basal cells and finally develop into a typical embryo with a suspensor. In contrast, isolated zygote protoplasts deprived of cell walls could enlarge but could not directionally elongate, as in vivo zygotes do before cell division, even when the cell wall was regenerated during in vitro culture. The zygote protoplasts could also undergo asymmetrical division to form one smaller and one larger daughter cell, which could develop into an embryonic callus or a globular embryo without a suspensor. Even cell walls that hung loosely around the protoplasts appeared to function, and were closely correlated with the orientation of the first zygotic division and the apical–basal axis, further indicating the essential role of the original zygotic cell wall in maintaining apical–basal polarity and cell‐division orientation, as well as subsequent cell differentiation during early embryo development in vitro.
Chlamydospore formation in Candida albicans and Candida dubliniensis– an enigmatic developmental programme
Authors: Staib Peter , Morschhäuser Joachim
Published: December 2006

Chlamydospore formation has served for a long time for identification of the human fungal pathogen Candida albicans, but the biological function of these structures still remains a secret. They have been proposed to allow survival in harsh environmental conditions, but this assumption remains to be proven. Chlamydospores are produced only by the two closely related species C. albicans and Candida dubliniensis, whose natural habitats are humans and warm‐blooded animals, but not by other Candida species that are also found outside animal hosts. However, no role in the pathogenesis of Candida infections has been assigned to these unusual cells and only a limited number of studies have been conducted in the past to unravel their function. The development of new molecular tools and the recent discovery of mating in C. albicans have also restimulated investigations to understand the morphogenesis and function of chlamydospores. The finding that chlamydospore formation is differentially controlled by certain environmental signals in C. albicans and C. dubliniensis has opened new approaches to study the regulation of this morphogenetic programme. These studies have already identified genes and signalling pathways that are required for chlamydospore production and should lead to a detailed understanding of this fascinating developmental process.
Primary subcutaneous zygomycosis due to Rhizopus oryzae in a 71‐year‐old man with normal immune status
Authors: Romano C. , Ghilardi A. , Massai L. , Capecchi P. L. , Miraccco C. , Fimiani M.
Published: December 2006

A case of primary subcutaneous zygomycosis due to Rhizopus oryzae is described in a 71‐year‐old man with normal immune status. Diagnosis was based on histological examination and culture of biopsy fragments from skin lesions. The patient recovered after itraconazole therapy (200 mg day−1 for 60 days followed by 100 mg day−1 for 45 days).
Tinea incognito due to Trichophyton mentagrophytes
Authors: Sánchez‐Castellanos María Elena , Mayorga‐Rodríguez Jorge Arturo , Sandoval‐Tress Cecilia , Hernández‐Torres Mercedes
Published: December 2006

Tinea incognito is a ringworm infection modified by corticosteroids. We report a case of a 2‐year‐old girl who developed tinea incognito due to Trichophyton mentagrophytes after applying methylprednisolone aceponate for 3 months. Diagnosis was confirmed by histopathologic and mycological examination, which led to the identification of Trichophyton mentagrophytes var. mentagrophytes, a zoophilic dermatophyte. Previous corticosteroid use in dermatophyte infections can alter their clinical appearance leading to misdiagnosis and delay in appropriate therapy.
Susceptibility and trailing growth of Candida albicans to fluconazole: results of a Korean multicentre study
Authors: Lee Mi‐Kyung , Kim Hye‐Ryoun , Kang Jung‐Oak , Kim Mi‐Na , Kim Eui‐Chong , Kim Jae‐Seok , Kim Jin‐Ju , Park Yeon‐Joon , Song Wonkeun , Shin Jong‐Hee , Lee Kyu‐Man , Lee Nam‐Yong , Lee Miae , Lee Wee‐Gyo , Lee Chang Kyu , Lee Hee‐Joo , Chang Chulhun L. , Choi Tae Yeal
Published: December 2006

The work reported here is the first nationwide, multicenter surveillance study conducted in Korea to obtain data on fluconazole susceptibility of Candida albicans (C. albicans) isolates. A total of 1137 isolates of C. albicans obtained from 17 university hospitals in South Korea during the 6‐month period, July through December 2004, were tested. No resistant strains were observed in any of the isolates. Only five of the 1137 isolates (0.44%) of C. albicans were found to be susceptible dose dependent, with all remaining strains (99.56%) susceptible to fluconazole. Trailing growth at 48 h was found in only four isolates (0.35%).
Assessment by human research ethics committees of potential conflicts of interest arising from pharmaceutical sponsorship of clinical research
Authors: Newcombe J. P. , Kerridge I. H.
Published: December 2006

Background: Conflicts of interest arising from pharmaceutical industry sponsorship of clinical research have the potential to bias research outcomes and ultimately prejudice patient care. It is unknown how Australian Human Research Ethics Committees (HREC) assess and manage such conflicts of interest. We aimed to gain an understanding of how HREC approach the problem of potential conflicts of interest arising from pharmaceutical sponsorship of clinical research.

Method: We conducted a survey of HREC chairpersons in New South Wales.

Results: HREC vary widely in their approaches to conflicts of interest, including in their use of National Health and Medical Research Council guidelines, which were often misinterpreted or overlooked. Many committees rely primarily on researchers disclosing potential conflicts of interest, whereas a majority of HREC use disclosure to research participants as the primary tool for preventing and managing conflicts of interest. Almost no HREC place limitations on researcher relationships with pharmaceutical companies.

Conclusion: These findings suggest reluctance on the part of HREC to regulate many potential conflicts of interest between researchers and pharmaceutical sponsors, which may arise from uncertainty regarding the meaning or significance of conflicts of interest in research, from ambiguity surrounding the role of HREC in assessing and managing conflicts of interest in research or from misinterpretation or ignorance of current National Health and Medical Research Council guidelines. Further review of policies and practices in this important area may prove beneficial in safeguarding clinical research and patient care while promoting continuing constructive engagement with the pharmaceutical industry.
Anger in palliative care: a clinical approach
Authors: Philip J. , Gold M. , Schwarz M. , Komesaroff P.
Published: December 2006

Anger in patients and families is a common problem in the care of persons with advanced disease. Whereas it is widely accepted that anger may be a justifiable reaction to significant illness and loss, it frequently creates difficulties for the doctors involved in care. In particular, there is often a personal impact on the doctor at whom anger is directed. This paper examines results of qualitative research with palliative care workers in the context of the broader published literature and the authors’ clinical experiences. The ability to interact effectively with angry patients is a skill that is often learned with experience and is extremely useful in both transforming the patients’ reaction into a more creative emotion and in developing a therapeutic relationship. Despite conscientious efforts, however, a few patients continue to be angry. A practical approach to anger, useful for the clinician directly involved in care, is outlined along with some strategies to adopt in the face of persistent anger.
Analysis of multidisciplinary lung cancer practice
Authors: Conron M. , Phuah S. , Steinfort D. , Dabscheck E. , Wright G. , Hart D.
Published: December 2006

Background: The aim of this study was to describe the activity of a lung cancer multidisciplinary clinic (MDC) and examine whether this model of clinical practice results in adherence to best‐practice guidelines.

Methods: Prospective analysis of demographic and clinical data in 431 patients referred to a lung cancer MDC for the management of known or suspected thoracic malignancy. Adherence was documented to clinically relevant guideline recommendations concerning timely and evidence‐based lung cancer management.

Results: Of 431 patients, 257 were diagnosed with primary lung cancer, mean age 68 years, 70% men and 90% current smokers or ex‐smokers. Only 21% were referred with known malignancy and 28% were asymptomatic. Overall, 51% had stages I and II non‐small‐cell lung cancer, with this bias towards early‐stage disease greatest in patients from rural areas. Histological confirmation of lung cancer was obtained in 92%. There was a high rate of adherence to international guideline recommendations concerning timely lung cancer diagnosis, staging and treatment implementation. Similarly, there was adherence to selected key evidence based recommendations for lung cancer management contained in national guidelines.

Conclusion: Within a MDC, patients receive timely diagnosis, staging and treatment according to evidence‐based guideline recommendations. The high proportion of patients receiving active treatment has implications for resource allocation. There is a referral bias towards patients with early non‐small‐cell lung cancer, particularly in rural patients, suggesting that further education about advances in metastatic lung cancer management is required. This study would support the establishment of regional lung cancer services with links to fully resourced MDC.
Sudden cardiac death in the young: a clinical genetic approach
Authors: Ingles J. , Semsarian C.
Published: December 2006

The sudden death of a young person is a devastating event for both the family and community. Over the last decade, significant advances have been made in understanding both the clinical and genetic basis of sudden cardiac death in the young. Many of the causes of sudden death in the young are due to genetic heart disorders, which can lead to both structural (e.g. hypertrophic cardiomyopathy) and arrhythmogenic (e.g. familial long QT syndrome) abnormalities. Most commonly, sudden cardiac death in the young can be the first presentation of an underlying heart problem, leaving the family at a loss as to why an otherwise healthy young person has died. Not only is this a tragic event for those involved, but it also presents a medical challenge to the clinician involved in the management of the surviving family members. Evaluation of families requires a multidisciplinary approach, which should include cardiologists, a clinical geneticist, a genetic counsellor and the forensic pathologist directly involved in the sudden death case. This multifaceted cardiac genetic service is crucial in the evaluation and management of the clinical, genetic, psychological and social complexities observed in families in which there has been a young sudden cardiac death.
Characteristics and outcome of type 2 diabetes in urban Aboriginal people: the Fremantle Diabetes Study
Authors: Davis T. M. E. , McAullay D. , Davis W. A. , Bruce D. G.
Published: December 2006

We analysed data from Aboriginal patients with type 2 diabetes recruited to the community‐based Fremantle Diabetes Study and compared them with those from the Anglo‐Celt participants. Diabetes prevalence among Aboriginal people in the Fremantle area was more than double that of Anglo‐Celts and the average age at diagnosis was 14 years or younger. Glycaemic control, urinary albumin :creatinine and the proportion of smokers were all higher in the Aboriginal group and there was evidence of lower diabetes‐related quality of life and high rates of disability at a young age. The Aboriginal patients died 18 years or younger than their Anglo‐Celt counterparts. Specialized, culturally‐sensitive and sustainable programmes are urgently needed to improve the management of diabetes in urban Aboriginal communities.
Effects of inhibition of fatty acid amide hydrolase vs. the anandamide membrane transporter on TRPV1‐mediated calcium responses in adult DRG neurons; the role of CB1 receptors
Authors: Millns P. J. , Chimenti M. , Ali N. , Ryland E. , De Lago E. , Fernandez‐Ruiz J. , Chapman V. , Kendall D. A.
Published: December 2006

The aim of the present study was to investigate the relationship between TRPV1 stimulation and endocannabinoid‐driven CB1 receptor‐mediated inhibition of activity in adult rat dorsal root ganglion (DRG) neurons, a model of primary afferent nociceptors. Calcium‐imaging studies were performed to compare the effects of the fatty acid amide hydrolase (FAAH) inhibitor URB597 (1 µm) vs. the anandamide (AEA) uptake inhibitor UCM707 (1 µm) on capsaicin (100 nm) and N‐arachidonoyl dopamine (NADA; 1 µm)‐evoked changes in intracellular calcium [Ca2+]i in DRG neurons. The ability of the CB1 receptor antagonist AM251 (1 µm) to modulate the effects of URB597 and UCM707 was also determined.

Suprafusion of NADA and capsaicin evoked robust increases in [Ca2+]i in DRG neurons (89 ± 4% and 132 ± 6% of the depolarizing KCl response, respectively). Co‐incubation with URB597 significantly attenuated both NADA and capsaicin‐evoked increases in [Ca2+]i (39 ± 3% and 79 ± 4% of KCl response, respectively). Similarly, co‐incubation with UCM707 significantly attenuated both NADA and capsaicin‐evoked increases in [Ca2+]i (59 ± 7% and 72 ± 4% of KCl response, respectively). The CB1 receptor antagonist AM251 significantly attenuated the effects of URB597 on NADA‐evoked increases in [Ca2+]i but not the effects of URB597 on capsaicin‐evoked increases in [Ca2+]i. By contrast, AM251 significantly attenuated the inhibitory effects of UCM707 on both NADA and capsaicin‐evoked increases in [Ca2+]i.

These data suggest that transport of both NADA and capsaicin into DRG neurons and the subsequent activation of TRPV1 is partly governed by FAAH‐dependent mechanisms as well as via the putative AEA membrane transporter.
Expression of histamine receptors and effect of histamine in the rat carotid body chemoafferent pathway
Authors: Lazarov Nikolai , Rozloznik Miroslav , Reindl Sebastian , Rey‐Ares Verónica , Dutschmann Mathias , Gratzl Manfred
Published: December 2006

Chemosensory information from peripheral arterial oxygen sensors in the carotid body is relayed by petrosal ganglion neurons to the respiratory networks in the medulla oblongata. Biogenic amines, including histamine, released from glomus (type I) cells of the carotid body are considered to be primary transmitters in hypoxic chemosensitivity. Immunocytochemistry at light‐and electron‐microscopical levels, and RT‐PCR, revealed the expression of histamine receptors 1 and 3 as well as histidine decarboxylase in the rat carotid body glomus cells and petrosal ganglion neurons. Histamine receptors 1 and 3, but not histidine decarboxylase, were also observed in the ventrolateral, intermediate and commissural subnuclei of the nucleus tractus solitarii in the medulla oblongata. In order to examine the possible role of histamine in the afferent branch of the respiratory system, we applied histamine receptor 1 and 3 agonists to the carotid body, which caused a mildly increased phrenic nerve activity in a working heart–brainstem preparation. Moreover, microinjection of antagonists of histamine receptors 1 and 3 into the nucleus tractus solitarii caused significant changes in the inspiratory timing and the chemoreceptor response. Our data show that histamine acting via histamine receptors 1 and 3 plays an important neuromodulatory role in the afferent control of chemosensitivity.
GSK3α exhibits β‐catenin and tau directed kinase activities that are modulated by Wnt
Authors: Asuni Ayodeji A. , Hooper Claudie , Reynolds C. Hugh , Lovestone Simon , Anderton Brian H. , Killick Richard
Published: December 2006

In the presence of a Wnt signal β‐catenin is spared from proteasomal degradation through a complex mechanism involving GSK3β, resulting in the transcription of Wnt target genes. In this study we have explored whether GSK3α, a related isoform, can also regulate nuclear β‐catenin levels and whether this and the tau‐directed kinase activity of GSK3α are modulated by Wnt. GSK3α or GSK3β and their substrates, β‐catenin and tau, were transiently expressed in mammalian cells. Immunoblotting revealed that GSK3α reduces nuclear levels of β‐catenin, whilst reporter gene assays demonstrated that GSK3α inhibits β‐catenin‐directed Tcf/Lef‐dependent transcription. Moreover, activation of the Wnt pathway was found to attenuate both the β‐catenin‐ and the tau‐directed kinase activities of GSK3α and GSK3β. By immunoprecipitation we also found that axin‐1, the β‐catenin destruction complex scaffold protein, binds GSK3α. In the light of these findings GSK3α warrants further investigation regarding its involvement in Wnt signalling and tauopathies such as Alzheimer's disease.
Effectiveness of Arndt endobronchial blockers in pediatric scoliosis surgery: a case series
Authors: BIRD G.T. , HALL M. , NEL L. , DAVIES E. , ROSS O.
Published: December 2006

Background:  Pediatric scoliosis surgery may require single lung ventilation for surgical access. Current methods of lung isolation are inadequate for some or all of these children. The Arndt endobronchial blocker (EBB) has been described for use in pediatric thoracic surgery to enable single lung ventilation (SLV). There are few data on its use in pediatric spinal deformity surgery. We report the successful use of the Arndt EBB in a series of these patients.

Methods:  Any patient undergoing surgical correction of scoliosis involving a lateral thoracotomy for an anterior approach was managed with an Arndt EBB (5, 7 and 9 Fr gauge) to facilitate SLV. All cases were undertaken by a pediatric anesthetist trained in pediatric bronchoscopy; a 2.2 or 2.8 mm pediatric fiberoptic scope was used for placement and positional confirmation.

Results:  Patients’ ages and weights ranged from 18 months to 18 years, and from 9.4 to 71 kg. All had idiopathic or congenital scoliosis; one underwent a vertical expansion prosthetic titanium rib (VEPTR) procedure. In all 20 patients, placement was easily and quickly achieved with no incorrect placements. There was one displacement after inflation, quickly corrected. Right upper lobe deflation proved difficult in one patient with high take‐off of the right upper lobe bronchus. The surgical field was excellent in all cases.

Conclusions:  In our case series, Arndt EBB provided a safe and highly effective means of single lung isolation for children undergoing pediatric scoliosis surgery.
Childhood obesity and anesthetic morbidity
Authors: SETZER NANCY , SAADE EDOUARD
Published: December 2006

Background:  Obesity is present in a significant proportion of children presenting for anesthesia. Although it is perceived that obese adults have more frequent complications, the incidence of complications in obese children is unknown. Because of anticipated difficulties with mask ventilation, anesthesia is most frequently induced intravenously in obese adults, whereas inhalation induction is usually preferred in uncooperative children with few visible veins. The purpose of this study was to examine and compare anesthetic related complications in obese children undergoing dental surgery with a similar group of nonobese individuals.

Methods:  The charts of 1133 American Society of Anesthesiology (ASA) physical status I and II children less than 12 years old who underwent general anesthesia for dental outpatient procedures in 2003 were retrospectively examined for patient height, weight, preoperative evaluation, anesthetic course and postoperative course. Body mass index was calculated and compared with international normative data to identify those children who were obese. Method of induction and perioperative complications were noted.

Results:  A total of 100 obese and 1033 nonobese children were identified. Demographically the two groups were comparable. Inhalation induction was used in the vast majority of obese (99%) and nonobese (99.7%) patients. Overall complication rate was low. Minor respiratory complications were more frequently noted in the obese group. These consisted primarily of a higher incidence of intraoperative oxygen desaturation (2% vs 0.19%) and higher requirements for unexpected overnight hospitalization (2% vs 0.19%). The only complication related directly to inhalation induction was noted in a nonobese child who vomited and aspirated on induction.

Conclusions:  Our study demonstrated a small increase in minor respiratory complications in obese children who underwent anesthesia. Inhalation induction was not associated with an increase in adverse events in this population.
Risk factors for impaired healing of the perineal wound after abdominoperineal resection of rectum for carcinoma
Authors: Artioukh D. Y. , Smith R. A. , Gokul K.
Published: December 2006

Objective  Nonhealing perineal wound is an unpleasant complication of surgical excision of the rectum and anus. The aim of the study was to evaluate the risk factors for impaired perineal wound healing after abdominoperineal resection (APR) of rectum for adenocarcinoma, particularly with the increasing use of neo‐adjuvant chemoradiation.

Method  The study included 38 consecutive patients (29 men, nine women; median age 66 years, range: 43–86), who underwent surgical excision of rectum and anus for adenocarcinoma from 1999 to 2004. Thirty‐seven patients underwent APR of rectum and one patient, who developed carcinoma in the background of chronic ulcerative colitis, had panproctocolectomy. Associations between the failure of the perineal wound to heal and a number of patient, tumour and treatment‐related variables were evaluated by Pearson chi‐square test or Fisher's exact test, as appropriate. A P‐value of <0.05 was considered significant. Multivariate statistical technique of principal component analysis was also used to identify risk factors and their relative contribution to impaired healing.

Results  Impaired healing of the perineal wound was observed in 10 (26%) of 38 patients. In four of them (11%) the wound remained nonhealed in 1 year after surgery. Preoperative radiotherapy, delayed primary closure of the wound and alcohol consumption in excess of 28 units/week was statistically significantly associated with impaired wound healing. Principal component analysis identified the following seven factors that cumulatively contributed to 96% of impaired healing: (i) distant metastases, (ii) preoperative radiotherapy, (iii) T‐stage of the tumour, (iv) smoking, (v) perioperative blood transfusion, (vi) preoperative chemotherapy and (vii) development of side effects of preoperative chemoradiation.

Conclusion  Patients who undergo APR of rectum are prone to impaired healing of the perineal wound if radiotherapy is used to treat malignancy prior to surgery and wound closure is delayed. In addition, the wound may not heal in patients with distant metastases, excessive alcohol consumption, present and past smokers and those who suffer adverse effects of preoperative chemoradiation and require blood transfusion.
Chemoprevention of colorectal cancer – a new target needed?
Authors: Spychalski M. , Dziki L. , Dziki A.
Published: December 2006

Objective  Novel treatments for colorectal cancer (CRC) include chemoprevention. Nonsteroidal anti‐inflammatory drugs (NSAIDs) were the first to be studied and an inverse association was proven between their use and the development of invasive CRC. The numerous side effects of NSAIDs led, however, to the search for safer drugs. These have included Coxibs (selective COX‐2 inhibitors). In this study, the role of coxibs in the chemoprevention of CRC is reviewed.

Results  Numerous in‐vitro and in‐vivo experiments have shown the effectiveness of coxibs in the chemoprevention of CRC. These have led to the registration of celecoxib by the USA Food and Drug Administration for the treatment of familial adenomatous polyposis. Further studies of coxibs have revealed an increased risk of serious cardiovascular events when compared with placebo. This finding has considerably decreased the opportunities for chemoprevention of CRC.

Conclusion  The multi‐directional activity of coxibs, which was the reason for their effectiveness against CRC development may be the key to proposing a new target area for chemoprevention. It has been shown that celecoxib partly inhibits the activity of NF‐κB, transcription factor involved in inflammation and carcinogenesis pathways. Modulation of its activation may be the future of effective CRC chemoprevention.
NOTHING BUT THE TRUTH? ON TRUTH AND DECEPTION IN DEMENTIA CARE
Authors: SCHERMER MAARTJE
Published: December 2006

Lies and deception are often used in the care for demented elderly and often with the best intentions. However, there is a strong moral presumption against all forms of lying and deceiving. The goal of this article is to examine and evaluate concrete examples of deception and lies in dementia care, while addressing some fundamental issues in the process.

It is argued that because dementia slowly diminishes the capacities one needs to distinguish between truths and falsehoods, the ability to be lied to also disappears. When the moral reasons to reject lying are explored, it becomes clear that most of them also hold where demented patients are concerned, though this also depends on the capacities of the patient. Lying, though prima facie wrong, can sometimes be justified with an appeal to well‐being. The relationship between well‐being and the truth is further explored. Two examples of deceiving demented patients for reasons of beneficence are discussed, from which it can be concluded that although in some cases beneficent lies or deception will not enhance patients’ well‐being, there are circumstances in which they do. In general, methods that enhance the well‐being of the patient without deception or lies should be favored above options that use deceit, and methods of getting the truth across without hurting the patient should be favored above blunt honesty. Finally, it is important to note that not only the patient but also the nursing and medical staff can be affected by the use of lies and deception.
LEGITIMIZING THE SHAMEFUL: END‐OF‐LIFE ETHICS AND THE POLITICAL ECONOMY OF DEATH
Authors: EPSTEIN MIRAN
Published: December 2006

This paper explores one of the most politically sensitive and intellectually neglected issues in bioethics – the interface between the history of contemporary end‐of‐life ethics and the economics of life and death. It suggests that contrary to general belief, economic impulses have increasingly become part of the conditions in which contemporary end‐of‐life ethics continues to evolve. Although this conclusion does not refute the philosophical justifications provided by the ethics for itself, it may cast new light upon its social role.
RAMPING UP AFRICAN GROWTH: LESSONS FROM FIVE DECADES OF GROWTH EXPERIENCE
Authors: Ndulu Benno J.
Published: December 2006

Since the 1960s economic growth rates have been far lower in sub‐Saharan Africa than in other developing regions. This poor performance has resulted primarily from endemic rent‐seeking and the over‐regulation of markets. To achieve high growth rates, African countries must improve the investment climate by reforming institutions, enhancing infrastructure and protecting property rights.
AN INTERPRETATION OF THE SIGNIFICANCE OF THE SECOND BATTLE OF WATERLOO
Authors: Prins Gwyn
Published: December 2006

Good governance is a pre‐condition for economic development. Good governance, in turn, requires peace. The second Battle of Waterloo, in Sierra Leone, showed what the West can do in this regard. A small military intervention, not hemmed in by the typical restrictions on what ‘peacekeepers’ can do, made a huge difference to the development prospects of the country. This has important implications for the use of external military forces as part of the overall strategy for poverty reduction in Africa.
INEQUALITY, ETHNICITY AND THE FIGHT AGAINST CORRUPTION IN AFRICA: A KENYAN PERSPECTIVE
Authors: Githongo John
Published: December 2006

Perceptions of inequality among different ethnic groups have the power to shape the fortunes of nations by affecting the political and economic choices of both ruling elites and their voters. In ethnically heterogeneous African states with a tradition of political patronage economic inequality is manifested along ethnic and regional lines. This paper argues for a constitutional dispensation that includes both the diffusion of executive power and systematic action in regard to structural economic inequalities that have assumed an ethnic expression.
AFRICAN TRANSITIONS AND THE RESOURCE CURSE: AN ALTERNATIVE PERSPECTIVE
Authors: Heller Thomas C.
Published: December 2006

Despite periodic rises in commodity prices, resource‐rich African countries have been characterised by state failure and low long‐term economic growth. Competing explanations for the resource curse are examined with a particular focus on political institutions. The effective privatisation of states is considered within an alternative theoretical framework of non‐democratic governance and non‐market economics. Given the nature of many African governments, international initiatives to encourage the development of effective markets and democracy may be inadequate to prevent increased resource rents from consolidating existing elites and their patronage regimes.