bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of magnetic field on parametrically driven surface waves
Authors: Paul Supriyo , Kumar Krishna
Published: December 2006

Stability analysis of parametrically driven surface waves in liquid metals in the presence of a uniform vertical magnetic field is presented. Floquet analysis gives various subharmonic and harmonic instability zones. The magnetic field stabilizes the onset of parametrically excited surface waves. The minima of all the instability zones are raised by a different amount as the Chandrasekhar number

is raised. The increase in the magnetic field leads to a series of bicritical points at a primary instability in thin layers of a liquid metal. The bicritical points involve one subharmonic and another harmonic solution of different wavenumbers. A tricritical point may also be triggered as a primary instability by tuning the magnetic field.
Stroke frequency, but not swimming speed, is related to body size in free-ranging seabirds, pinnipeds and cetaceans
Authors: Sato Katsufumi , Watanuki Yutaka , Takahashi Akinori , Miller Patrick J.O , Tanaka Hideji , Kawabe Ryo , Ponganis Paul J , Handrich Yves , Akamatsu Tomonari , Watanabe Yuuki , Mitani Yoko , Costa Daniel P , Bost Charles-André , Aoki Kagari , Amano Masao , Trathan Phil , Shapiro Ari , Naito Yasuhiko
Published: December 2006

It is obvious, at least qualitatively, that small animals move their locomotory apparatus faster than large animals: small insects move their wings invisibly fast, while large birds flap their wings slowly. However, quantitative observations have been difficult to obtain from free-ranging swimming animals. We surveyed the swimming behaviour of animals ranging from 0.5 kg seabirds to 30 000 kg sperm whales using animal-borne accelerometers. Dominant stroke cycle frequencies of swimming specialist seabirds and marine mammals were proportional tomass−0.29(R2=0.99,n=17 groups), while propulsive swimming speeds of 1–2 m s−1were independent of body size. This scaling relationship, obtained from breath-hold divers expected to swim optimally to conserve oxygen, does not agree with recent theoretical predictions for optimal swimming. Seabirds that use their wings for both swimming and flying stroked at a lower frequency than other swimming specialists of the same size, suggesting a morphological trade-off with wing size and stroke frequency representing a compromise. In contrast, foot-propelled diving birds such as shags had similar stroke frequencies as other swimming specialists. These results suggest that muscle characteristics may constrain swimming during cruising travel, with convergence among diving specialists in the proportions and contraction rates of propulsive muscles.
Detection of a population replacement at the Classic–Postclassic transition in Mexico
Authors: González-José Rolando , Martínez-Abadías Neus , González-Martín Antonio , Bautista-Martínez Josefina , Gómez-Valdés Jorge , Quinto Mirsha , Hernández Miquel
Published: December 2006

The Mexica Empire reached an outstanding social, economic and politic organization among Mesoamerican civilizations. Even though archaeology and history provide substantial information about their past, their biological origin and the demographic consequences of their settlement in the Central Valley of Mexico remain unsolved. Two main hypotheses compete to explain the Mexica origin: a social reorganization of the groups already present in the Central Valley after the fall of the Classic centres or a population replacement of the Mesoamerican groups by migrants from the north and the consequent setting up of the Mexica society. Here, we show that the main changes in the facial phenotype occur during the Classic–Postclassic transition, rather than in the rise of the Mexica. Furthermore, Mexica facial morphology seems to be already present in the early phases of the Postclassic epoch and is not related to the northern facial pattern. A combination of geometric morphometrics with Relethford–Blangero analyses of within- versus among-group variation indicates that Postclassic groups are more variable than expected. This result suggests that intense gene exchange was likely after the fall of the Classic and maybe responsible for the Postclassic facial phenotype. The source population for the Postclassic groups could be located somewhere in western Mesoamerica, since North Mexico and Central Mesoamerican Preclassic and Classic groups are clearly divergent from the Postclassic ones. Similarity among Preclassic and Classic groups and those from Aridoamerica could be reflecting the ancestral phenotypic pattern characteristic of the groups that first settled Mesoamerica.
Biomimetic approaches to the control of underwater walking machines
Authors: Ayers Joseph , Witting Jan
Published: December 2006

We have developed a biomimetic robot based on the American lobster. The robot is designed to achieve the performance advantages of the animal model by adopting biomechanical features and neurobiological control principles. Three types of controllers are described. The first is a state machine based on the connectivity and dynamics of the lobster central pattern generator (CPG). The state machine controls myomorphic actuators based on shape memory alloys (SMAs) and responds to environmental perturbation through sensors that employ a labelled-line code. The controller supports a library of action patterns and exteroceptive reflexes to mediate tactile navigation, obstacle negotiation and adaptation to surge. We are extending this controller to neuronal network-based models. A second type of leg CPG is based on synaptic networks of electronic neurons and has been adapted to control the SMA actuated leg. A brain is being developed using layered reflexes based on discrete time map-based neurons.
The biodiversity of the deep Southern Ocean benthos
Authors: Brandt A , De Broyer C , De Mesel I , Ellingsen K.E , Gooday A.J , Hilbig B , Linse K , Thomson M.R.A , Tyler P.A
Published: December 2006

Our knowledge of the biodiversity of the Southern Ocean (SO) deep benthos is scarce. In this review, we describe the general biodiversity patterns of meio-, macro- and megafaunal taxa, based on historical and recent expeditions, and against the background of the geological events and phylogenetic relationships that have influenced the biodiversity and evolution of the investigated taxa. The relationship of the fauna to environmental parameters, such as water depth, sediment type, food availability and carbonate solubility, as well as species interrelationships, probably have shaped present-day biodiversity patterns as much as evolution. However, different taxa exhibit different large-scale biodiversity and biogeographic patterns. Moreover, there is rarely any clear relationship of biodiversity pattern with depth, latitude or environmental parameters, such as sediment composition or grain size. Similarities and differences between the SO biodiversity and biodiversity of global oceans are outlined. The high percentage (often more than 90%) of new species in almost all taxa, as well as the high degree of endemism of many groups, may reflect undersampling of the area, and it is likely to decrease as more information is gathered about SO deep-sea biodiversity by future expeditions. Indeed, among certain taxa such as the Foraminifera, close links at the species level are already apparent between deep Weddell Sea faunas and those from similar depths in the North Atlantic and Arctic. With regard to the vertical zonation from the shelf edge into deep water, biodiversity patterns among some taxa in the SO might differ from those in other deep-sea areas, due to the deep Antarctic shelf and the evolution of eurybathy in many species, as well as to deep-water production that can fuel the SO deep sea with freshly produced organic matter derived not only from phytoplankton, but also from ice algae.
Trophic interactions within the Ross Sea continental shelf ecosystem
Authors: Smith Walker O , Ainley David G , Cattaneo-Vietti Riccardo
Published: December 2006

The continental shelf of the Ross Sea is one of the Antarctic's most intensively studied regions. We review the available data on the region's physical characteristics (currents and ice concentrations) and their spatial variations, as well as components of the neritic food web, including lower and middle levels (phytoplankton, zooplankton, krill, fishes), the upper trophic levels (seals, penguins, pelagic birds, whales) and benthic fauna. A hypothetical food web is presented. Biotic interactions, such as the role ofEuphausia crystallorophiasandPleuragramma antarcticumas grazers of lower levels and food for higher trophic levels, are suggested as being critical. The neritic food web contrasts dramatically with others in the Antarctic that appear to be structured around the keystone speciesEuphausia superba. Similarly, we suggest that benthic–pelagic coupling is stronger in the Ross Sea than in most other Antarctic regions. We also highlight many of the unknowns within the food web, and discuss the impacts of a changing Ross Sea habitat on the ecosystem.
Climate change and the marine ecosystem of the western Antarctic Peninsula
Authors: Clarke Andrew , Murphy Eugene J , Meredith Michael P , King John C , Peck Lloyd S , Barnes David K.A , Smith Raymond C
Published: December 2006

The Antarctic Peninsula is experiencing one of the fastest rates of regional climate change on Earth, resulting in the collapse of ice shelves, the retreat of glaciers and the exposure of new terrestrial habitat. In the nearby oceanic system, winter sea ice in the Bellingshausen and Amundsen seas has decreased in extent by 10% per decade, and shortened in seasonal duration. Surface waters have warmed by more than 1 K since the 1950s, and the Circumpolar Deep Water (CDW) of the Antarctic Circumpolar Current has also warmed. Of the changes observed in the marine ecosystem of the western Antarctic Peninsula (WAP) region to date, alterations in winter sea ice dynamics are the most likely to have had a direct impact on the marine fauna, principally through shifts in the extent and timing of habitat for ice-associated biota. Warming of seawater at depths belowca100 m has yet to reach the levels that are biologically significant. Continued warming, or a change in the frequency of the flooding of CDW onto the WAP continental shelf may, however, induce sublethal effects that influence ecological interactions and hence food-web operation. The best evidence for recent changes in the ecosystem may come from organisms which record aspects of their population dynamics in their skeleton (such as molluscs or brachiopods) or where ecological interactions are preserved (such as in encrusting biota of hard substrata). In addition, a southwards shift of marine isotherms may induce a parallel migration of some taxa similar to that observed on land. The complexity of the Southern Ocean food web and the nonlinear nature of many interactions mean that predictions based on short-term studies of a small number of species are likely to be misleading.
Algal and cyanobacterial secondary metabolites in freshwaters: a comparison of allelopathic compounds and toxins
Authors: LEFLAIVE JOSE´PHINE , TEN‐HAGE LOÏC
Published: December 2006

1. The photoautotrophic micro‐organisms collectively termed ‘micro‐algae’ (including micro‐eukaryotes and cyanobacteria) are known to produce a wide range of secondary metabolites with various biological actions. A small subset of these compounds has been identified. Some of them, termed allelopathic compounds, have been shown to play a role in allelopathy, defined here as inhibitory effects of secondary metabolites against either competitors or predators. Freshwater cyanobacteria also produce some secondary metabolites, termed toxins, which are highly toxic for animals.

2. While allelopathic compounds play a role in the interactions between the emitter organisms and their direct competitors or predators, toxins are categorised according to their toxic effect on several organisms, including some that may not be present in their immediate environment. However, these two definitions are not mutually exclusive. This review considers the evolutionary, ecological and physiological aspects of the production of allelopathic compounds by micro‐algae in freshwaters, and compares the characteristics of allelopathic compounds with those of toxins.

3. Allelopathic compounds include alkaloids, cyclic peptides, terpens and volatile organic compounds. Toxins include alkaloids, cyclic peptides and lipopolysaccharides. No allelopathic compound type is associated with a particular phylogenetic group of algae. In contrast, freshwater toxins are only produced by cyanobacteria belonging to a restricted number of genera. Allelopathic compounds have various modes of action, from inhibition of photosynthesis to oxidative stress or cellular paralysis. Toxins are often enzyme inhibitors, or interfere with cell membrane receptors.

4. The ecological roles of allelopathic compounds have been well identified in several cases, but those of toxins are still debated. In the light of descriptions of negative effects of toxins on both micro‐invertebrates and photoautotrophic organisms, we suggest that at least some toxins should actually be considered as allelopathic compounds. Further research on toxic secondary metabolites in freshwaters is now needed, with emphasis on the ecological effects of the compounds in the immediate environment of the emitter algae.
Design of a clustered observational study to predict emergency admissions in the elderly: statistical reasoning in clinical practice
Authors: Lancaster Gillian A. , Chellaswamy Hannah , Taylor Steve , Lyon David , Dowrick Chris
Published: December 2006

Objective  To describe the statistical design issues and practical considerations that had to be addressed in setting up a clustered observational study of emergency admission to hospital of elderly people.

Study design and setting  Clustered observational study (sample survey) of elderly people registered with 18 general practices in Halton Primary Care Trust in the north‐west of England.

Results  The statistical design features that warranted particular attention were sample size determination, intra‐class correlation, sampling and recruitment, bias and confounding. Pragmatic decisions based on derived scenarios of different design effects are discussed. A pilot study was carried out in one practice. From the remaining practices, a total of 4000 people were sampled, stratified by gender. The average cluster size was 200 and the intra‐class correlation coefficient for the emergency admission outcome was 0.00034, 95% confidence interval (0–0.008).

Conclusion  Studies that involve sampling from clusters of people are common in a wide range of healthcare settings. The clustering adds an extra level of complexity to the study design. This study provides an empirical illustration of the importance of statistical as well as clinical reasoning in study design in clinical practice.
Home telemonitoring of patients with diabetes: a systematic assessment of observed effects
Authors: Jaana Mirou , Paré Guy
Published: December 2006

Rationale, aims and objectives  Diabetes represents a common chronic disease continuously growing worldwide. Unless closely monitored, it can be associated with serious complications and high expenditures. Telemonitoring is a patient management approach increasingly used with chronic illnesses. It supports timely transmission and remote interpretation of patients’ data for follow‐up and preventive interventions. No comprehensive review exists on all aspects of diabetes ‘home telemonitoring’ and its effects. The objective of this study is to provide a systematic review of this approach and its effect at the informational, clinical, behavioural, structural and economical levels.

Methods  A comprehensive literature review was conducted on Medline and Cochrane Library to identify relevant articles. The keywords used include diabetes, telemonitoring, home monitoring, telecare and telemedicine.

Results  Seventeen studies using diverse technologies and transmitting different clinical, medical and behavioural data were found. Significant impacts were observed namely at the behavioural, clinical and structural levels. Minimal technical problems and no cost‐benefit and cost‐effectiveness analyses were reported.

Conclusion  Close management of diabetic patients through telemonitoring showed significant reduction in HbA1c and complications, good receptiveness by patients and patient empowerment and education. Yet, the magnitude of its effects remains debatable, especially with the variation in patients’ characteristics (e.g. background, ability for self‐management, medical condition), samples selection and approach for treatment of control groups. Further investigation of telemonitoring efficacy and cost‐effectiveness over longer periods of time, and larger samples is needed. Assessment of the attitude of providers is also important in light of their heavy workload and issues of reimbursement.
Does a Cesarean section delivery always cost more than a vaginal delivery?
Authors: Kazandjian Vahé A. , Chaulk C. Patrick , Ogunbo Sam , Wicker Karol
Published: December 2006

There is evidence that average total charges per episode of child birth depend on maternal plus child length of stay, neonatal intensive care unit (NICU) utilization, maternal race and mode of delivery. In particular, when maternal and child records are linked, this study suggests that when adjusted for maternal characteristics, the cost of vaginal deliveries followed by NICU utilization may be higher than the cost of Cesarean sections and NICU utilization.

Objective  Cesarean section, one of the most frequently performed surgical procedures on women, is rising globally and in the USA. Much of the current Cesarean section literature focuses on reporting geographic and hospital‐specific variations, but little has been published about the clinical and demographic characteristics of the patients, and even less about the economic consequences of a Cesarean section delivery compared with a vaginal delivery [e.g. the total hospital charges and length of neonatal intensive care unit‐NICU‐stay] of a birth episode. To examine these relationships further, three urban Baltimore hospitals volunteered in 2004 to participate in a retrospective chart review that linked mother and child hospital records.

Methods  1172 mother–child records were randomly selected and data regarding maternal co‐morbidities, age, infant weight along with transfer to neonatal intensive care units, and economic data were extracted from the mother and child charts.

Conclusion  Average total charges for vaginal deliveries [maternal plus total baby charges that includes NICU utilization (X = $17 624.38)] may be higher than average total charges for Cesarean sections [maternal plus total baby charges that includes NICU utilization (X = $13 805.47)]. Specifically, maternal race – being African American – was indirectly associated with overall charges through its association with mode of delivery and NICU utilization patterns. The presence of maternal co‐morbidities – Herpes Simplex Virus, hypertension and diabetes – most probably influenced babies’ hospital stay charges as well as NICU charges when transferred to NICU following both vaginal and Cesarean section deliveries. Thus, prenatal care targeting co‐morbidities management may reduce the odds of a newborn’s transfer to NICU thus avoiding greater lengths of stay, medical care and charges. Recommendations for obstetrical practices as well as health care policy on their charges should not assume that Cesarean section deliveries are always costlier than vaginal deliveries.
A centralized Pharmacy Unit for cytotoxic drugs in accordance with Italian legislation
Authors: Baldo Paolo , Bertola Antonella , Basaglia Giancarlo , Moneghini Mariarosa , Sorio Roberto , Zibardi Enrico , Lazzarini Renzo , De Paoli Paolo
Published: December 2006

Rationale  In May 2002, a centralized Unit for cytotoxic drug preparations [Unità Farmaci Antiblastici (UFA)] was established at the Centro di Riferimento Oncologico, Aviano, Italy. The Unit was created following provisions under Law 626/94 (Legislative Decree – Ministry of Health), governing the safe handling of cytotoxic drugs. New guidelines governing drug preparation (‘NBP’ standards of preparation) published in Italian Pharmacopoeia (2002, XI Edition) have been mandatory since 2004 and set out rules for proper pharmacy practice applicable also to antineoplastic drug preparations.

Aims and objectives  To review legislation on cytotoxic drug preparation and compliance within our Unit, to assess current quality levels and identify those areas requiring improvement.

Methods  The study reviewed: (1) the organization and equipment of the Unit UFA and its working methodology; (2) written documentation concerning work procedures; (3) the stability and sterility of injectable drug formulations; (4) staff training, occupational exposure and risk management; (5) accidents and mistakes occurring in the UFA service.

Results  The study showed up the strengths of our Unit and identified those areas which need improvement to guarantee product quality excellence.

Conclusions  A critical evaluation of the whole cytotoxic preparation process is a useful method for quality improvements to be initiated. Knowledge regarding risks, techniques, and procedures for handling antineoplastic drugs is growing. Ongoing analysis will ensure greater patient and health care worker safety.
‘New Bornean carnivore’ is most likely a little known flying squirrel
Authors: MEIJAARD ERIK , KITCHENER ANDREW C. , SMEENK CHRIS
Published: December 2006

We analysed two camera‐trap photos of an alleged new species of carnivore from Kalimantan, Borneo, Indonesia.

Comparisons of the features seen in the photos with morphological features of 17 similar‐looking species from the region suggest that the animal is not a new species of carnivore, as had been widely speculated, but is most likely a rarely seen species of flying squirrel, probably Aeromys thomasi.

We advocate continuing adherence to the formalities of species description based on actual specimens and a formal review process. Even informal announcements about possible new species based on photographs or other indirect evidence should adopt a cautionary approach. All the possibilities should be eliminated using any available means, such as comparative morphometrics and assessments of body shape and posture, and coat colour.
Glacial refugia of mammals in Europe: evidence from fossil records
Authors: SOMMER R. S. , NADACHOWSKI A.
Published: December 2006

Glacial refugia were core areas for the survival of temperate species during unfavourable environmental conditions and were the sources of postglacial recolonizations. Unfortunately, the locations of glacial refugia of animals and plants are usually described by models, without reference to facts about real geographical ranges at that time.

Careful consideration of the faunal assemblages of archaeological sites from the Younger Palaeolithic, which are precisely dated to the Last Glacial Maximum (LGM), gives indications about the distribution of species during the LGM (23 000–16 000 bp) and provides evidence for the locations of glacial refugia for mammalian species in Europe.

In Europe, 47 LGM sites, dating from 23 000 to 16 000 bp and containing typical temperate mammal species, have been described. The geographical range of these archaeological sites clearly shows a distribution which differs from the hypothesized traditional refuge areas of the temperate fauna. A considerable number of sites situated in the Dordogne in south‐western France and the Carpathian region contain records of red deer Cervus elaphus, roe deer Capreolus capreolus, wild boar Sus scrofa and red fox Vulpes vulpes.

The faunal composition of the majority of the evaluated Palaeolithic sites in the southern European peninsulas (with the exception of Greece), as well as France and the Carpathian region, indicates the co‐occurrence of these temperate species with cold‐adapted faunal elements such as mammoth Mammuthus primigenius and/or reindeer Rangifer tarandus.

The survival of species in Central European refugia would have significant consequences for phylogeography and would be revealed by the dominant distribution of haplotypes, originating from this region. A Carpathian refuge could also be the reason for the very early records of small mammals or mustelids from the Late‐Glacial or Interstadials before the LGM in regions like southern Germany.
Identification of Candida species isolated from patients in intensive care unit and in vitro susceptibility to fluconazole for a 3‐year period
Authors: Comert Fusun , Kulah Canan , Aktas Elif , Eroglu Ozlem , Ozlu Nagihan
Published: December 2006

Species level identification of Candida and antifungal susceptibility testing is not generally performed in routine laboratory practice. There is limited information about the distribution of Candida species and antifungal susceptibility in Turkey. In this study, we aimed at identifying Candida isolates to species level from various samples obtained from patients treated in an intensive care unit between 2002 and 2005 and to evaluate fluconazole susceptibilities of the isolates. A total of 320 Candida isolates obtained from 270 patients were identified by conventional methods and using API (Candida and/or 20C AUX) system. Antifungal susceptibility testing was performed by broth microdilution method. Candida albicans was isolated with the highest frequency (65.6%) followed by C. parapsilosis (11.3%), C. glabrata (8.8%) and C. tropicalis (7.8%). Of all the isolates, 92.9% revealed susceptibility to fluconazole. Susceptibility to fluconazole was highest for C. albicans followed by C. parapsilosis and C. glabrata. The MIC90 values for C. albicans, C. parapsilosis, C. glabrata and C. tropicalis were 1, 2, 8 and 4 μg ml−1 respectively. Fluconazole remains effective against both C. albicans and the majority of non‐albicans Candida species. In this study, we determine the distribution of Candida species and evaluate the susceptibilities of the isolates, particularly for the azoles.
Voriconazole and multidrug resistance in Candida albicans
Authors: Wakieć Roland , Prasad Rajendra , Morschhäuser Joachim , Barchiesi Francesco , Borowski Edward , Milewski Sławomir
Published: December 2006

In vitro activity of voriconazole against fluconazole‐resistant Candida albicans clinical isolates with identified molecular basis of multidrug resistance (MDR) and recombinant Saccharomyces cerevisiae expressing C. albicans genes coding for major multidrug transporters, CaCdr1p, CaCdr2p or CaMdr1p, was compared with that of fluconazole, ketoconazole and clotrimazole. It was found that overexpression of the MDR genes made the yeast cells less susceptible to voriconazole. The voriconazole resistance indexes, defined as a ratio of minimum inhibitory concentrations (MICs) determined for MDR and sensitive cells, were comparable with those determined for fluconazole. Voriconazole effectively competed with rhodamine 6G for the active efflux mediated by CaCdr1p and CaCdr2p.
Oral submucous fibrosis and oral yeast carriage – a case control study in Sri Lankan patients
Authors: Ariyawardana A. , Panagoda G. J. , Fernando H. N. , Ellepola A. N. B. , Tilakaratne W. M. , Samaranayake L. P.
Published: December 2006

Oral submucous fibrosis (OSMF) is a well‐known precancerous condition. Epithelial atrophy is one of the key features in OSMF. Presence of Candida in the mouth together with epithelial changes may predispose to candidal infection. Candidal infection together with other co‐factors may also induce epithelial atypia and dysplasia leading to malignant change. The purpose of this study was to determine the prevalence of oral yeast carriage in patients with OSMF and to compare the carriage with the normal individuals. Thirty patients with histologically proven OSMF and healthy subjects were used as the test and control respectively. Oral rinse samples were collected from all the subjects and cultured on Sabouraud's agar. Species were identified using API 32C AUX identification kits. Nineteen (63.6%) of the test group and 15 (50%) of the control group had yeast isolated from their mouth. The carriage of yeast in the OSMF group was not statistically significant compared with the control group. We isolated C. dubliniensis in Sri Lanka for the first time and interestingly from the oral cavities of both OSMF patients and healthy individuals.
Effect of chronic diseases and associated psychological distress on health‐related quality of life
Authors: Keles H. , Ekici A. , Ekici M. , Bulcun E. , Altinkaya V.
Published: December 2006

Background: The purpose of this study was to clarify the correlations between the presence of comorbidities and psychological distress and health‐related quality of life (HRQL). This was a population‐based cross‐sectional study.

Methods: Parents and grandparents of students from seven randomly selected primary schools in the city centre were asked to answer questionnaires sent by their children. All subjects were questioned for somatic diseases, psychological distress and HRQL by Health Questionnaire, Hospital Anxiety and Depression scale and short‐form‐12 health survey, respectively.

Results: Out of 5024 parents and grandparents (mean age 52.3 ± 14.3 years, range 20–104 years) of primary school students 4605 returned the questionnaires, a figure that corresponds to the overall response rate of 91.6%. Chronic diseases substantially reduced HRQL and this effect did not differ markedly with the type of chronic disease. Association of comorbidities with psychological distress further impaired HRQL. As the number of chronic diseases was increased, HRQL and physical and mental functioning declined. The worst HRQL was observed in subjects who had five or more comorbidities associated with psychological distress.

Conclusion: The present study indicates significant adverse effects of chronic diseases and psychological distress on HRQL in adults, the effect of psychological distress being the most important. Our results lead us to suggest that in the management of comorbidities, the detection of the presence and severity of associated psychological distress and its treatment, besides the specific treatment of comorbidities, may provide dramatic improvement in HRQL of the patients.
Assessment and treatment of pulmonary arterial hypertension: an Australian perspective in 2006
Authors: Gabbay E. , Reed A. , Williams T. J.
Published: December 2006

Pulmonary arterial hypertension is a group of diseases which forms a small subset of those with elevated pulmonary artery pressure (pulmonary hypertension). The recent development of selective pulmonary vasodilator has lead to a substantial resurgence of interest in what have been previously regarded as rare and incurable diseases. This review aims to describe the spectrum of pulmonary vascular diseases, the evolving understanding as to pathogenesis, the evolving evidence of efficacy for drug therapies, trying to put this into a contemporary Australian context. Several key pathogenic pathways may be involved: prostacycline, Nitric Oxide‐cGMP‐phosphodiesterase 5 and endothelin– all of which are exploited for therapeutic benefit by newly available drug therapies. A recently modified classification system reasserts the importance of precise diagnosis. The cardinal symptom of exertional dyspnea warrants careful evaluation in an attempt to prevent (frequently occurring) substantial delay in diagnosis. Echocardiogram is the cornerstone of screening for pulmonary arterial hypertension; however, a detailed evaluation including a carefully performed right heart catheterisation with sufficient data to allow calculation of pulmonary vascular resistance is key to accurate diagnosis. These new approaches to therapy are already substantially improving quality of life and prognosis.
Homeostatic control of the excitation–inhibition balance in cortical layer 5 pyramidal neurons
Authors: Le Roux Nicolas , Amar Muriel , Baux Gérard , Fossier Philippe
Published: December 2006

Homeostatic regulation in the brain is thought to be achieved through a control of the synaptic strength by close interactions between excitation and inhibition in cortical circuits. We recorded in a layer 5 pyramidal neuron of rat cortex the composite response to an electrical stimulation of various layers (2–3, 4 or 6). Decomposition of the global conductance change in its excitatory and inhibitory components permits a direct measurement of excitation–inhibition (E‐I) balance. Whatever the stimulated layer was, afferent inputs led to a conductance change consisting of 20% excitation and 80% inhibition. Changing synaptic strengths in cortical networks by using a high‐frequency of stimulation (HFS) protocol or a low‐frequency of stimulation (LFS) protocol (classically used to induce long‐term potentiation or long‐term depression at the synaptic level) were checked in order to disrupt this balance. Application of HFS protocols in layers 2–3, 4 or 6, or of LFS protocols in layer 4 induced, respectively, long‐term paralleled increases or long‐term paralleled decreases in E and I which did not change the E‐I balance. LFS protocols in layers 2–3 or 6 decreased E but not I and disrupted the balance. It is proposed that regulatory mechanisms might be mainly sustained by recurrent connectivity between excitatory and inhibitory neuronal circuits and by modulation of shunting GABAA inhibition in the layer 5 pyramidal neuron.
Estradiol stimulates progenitor cell division in the ventricular and subventricular zones of the embryonic neocortex
Authors: Martínez‐Cerdeño Verónica , Noctor Stephen C. , Kriegstein Arnold R.
Published: December 2006

Two distinct populations of cerebral cortical progenitor cells that generate neurons during embryogenesis have been identified: radial glial cells and intermediate progenitor cells. Despite advances in our understanding of progenitor cell populations, we know relatively little about factors that regulate their proliferative behaviour. 17‐β‐Estradiol (E2) is present in the adult and developing mammalian brain, and plays an important role in central nervous system processes such as neuronal differentiation, survival and plasticity. E2 also stimulates neurogenesis in the adult dentate gyrus. We examined the role of E2 during embryonic cortical neurogenesis through immunohistochemistry, in situ hybridization, functional enzyme assay, organotypic culture and in utero administration of estradiol‐blocking agents in mice. We show that aromatase, the E2 synthesizing enzyme, is present in the embryonic neocortex, that estrogen receptor‐α is present in progenitor cells during cortical neurogenesis, that in vitro E2 administration rapidly promotes proliferation, and that in utero blockade of estrogen receptors decreases proliferation of embryonic cortical progenitor cells. Furthermore, the E2 inhibitor α‐fetoprotein is expressed at high levels by radial glial cells but at lower levels by intermediate progenitor cells, suggesting that E2 differentially influences the proliferation of these cortical progenitor cell types. These findings demonstrate a new functional role for E2 as a proliferative agent during critical stages of cerebral cortex development.
Use of the ASA Physical Status Grading System in pediatric practice
Authors: APLIN STEPHANIE , BAINES DAVID , DE LIMA JONATHAN
Published: December 2006

Background:  The American Society of Anesthesiologists (ASA) Grading System is widely used to describe preoperative physical status. Inconsistency of grading between anesthetists has been demonstrated in studies using hypothetical adult patient scenarios. We aimed to investigate the use and interrater reliability of the ASA Grading System in pediatric anesthesia practice.

Methods:  A two‐part questionnaire was mailed to all 176 current members of the Society of Paediatric Anaesthesia in New Zealand and Australia (SPANZA). The first part of the questionnaire obtained information regarding type of practice, use of the ASA Grading System, opinions regarding grading systems in general and opinions as to the limitations of the ASA System. In Part II, respondents were presented with 15 hypothetical patient scenarios and asked to grade them using the ASA System. The scenarios were designed to cover a range of ages and conditions common in pediatric practice.

Results:  There were 130 replies (73.9%) after two mailings. The majority of respondents had been in predominantly pediatric practice for >5 years, had read the ASA Grading System within the last 2 years, and used it regularly. However, 30% modified the grading system for use in pediatrics.

Many limitations of the ASA System in pediatric practice were identified. There was considerable lack of consistency in the grading of the hypothetical patient scenarios, with each scenario receiving at least three different ASA gradings. Case scenarios involving trauma or airway compromise were associated with greater inconsistency. There was no demonstrable correlation between grading consistency and patient age, familiarity with the ASA Grading System or experience of the anesthetist.

Conclusions:  The ASA Grading System shows poor interrater reliability in pediatric practice, as it does in adults. This should be borne in mind when using the ASA System for clinical or scientific work in pediatrics. A physical status grading system developed specifically for use in pediatrics may reduce inconsistency.
Persistent symptoms of functional outlet obstruction after rectocele repair
Authors: Puigdollers A. , Fernández‐Fraga X. , Azpiroz F.
Published: December 2006

Background  Rectocele is frequently associated with constipation, but it is not known whether a causal relationship exists.

Objective  To determine the effect of rectocele repair on symptoms of constipation.

Method  Thirty‐five women (28–79 years) consecutively operated for rectocele repair (11 transanal approach and 24 transperineal) were included in the prospective study. Using a structured questionnaire, the following criteria for constipation were evaluated: (a) straining, (b) sensation of anal blockage, (c) sensation of incomplete evacuation, (d) manual manoeuvres to facilitate defecation, (e) stool consistency and (f) stool frequency. The evaluation was performed before and 1 year after rectocele repair.

Results  Before the operation all patients had two or more constipation criteria, including sensation of anal blockage. One year after the operation, the incidence of all symptoms significantly improved (from 3.9 ± 0.2 to 1.9 ± 0.3; P < 0.01). However, in 18 patients two or more criteria of constipation persisted, two patients presented one criterion, and only 15 patients became asymptomatic. Neither parity nor the type of surgical approach (endorectal vs transperineal) was related to the response to treatment. In eight patients who had a previous hysterectomy the result was significantly worse.

Conclusion  In a considerable proportion of patients, constipation persists after rectocele repair, suggesting that these symptoms are related to an underlying dysfunction.
DEATH AND TRANSPLANTATION: LET’S TRY TO GET THINGS METHODOLOGICALLY STRAIGHT
Authors: BONIOLO GIOVANNI
Published: December 2006

The purpose of this paper is methodological. I begin by showing the methodological frailties of both the heart and brain approach to the criteria of death used in connection with organ transplantation. I then clarify what a definition is. Finally, I propose to abandon the definition of death, and suggest a pragmatic definition of ‘explantability window’.
INFORMED CONSENT AND THE MISATTRIBUTED PATERNITY PROBLEM IN GENETIC COUNSELING
Authors: LUCAST ERICA K.
Published: December 2006

When misattributed paternity is discovered in the course of genetic testing, a genetic counselor is presented with a dilemma concerning whether to reveal this information to the clients. She is committed to treating the clients equally and enabling informed decision making, but disclosing the information may carry consequences for the woman that the counselor cannot judge in advance. A frequent suggestion aimed at avoiding this problem is to include the risk of discovering nonpaternity in the informed consent process for counseling. In this paper I argue that such a move does not resolve the problem, because the conflict hinges on the interpretation of equality on which the counselor operates. Given the principles of genetic counseling, neither construal of equality yields a satisfactory solution to the conflict. In fact, I conclude that including nonpaternity in informed consent is not endorsed by either view, and we are still left with the question of what to do should nonpaternity be discovered. I suggest a compromise position concerning disclosure, involving revealing relevant genetic information but withholding nonpaternity when possible.
Real Output Co‐movements in East Asia: Any Evidence for a Monetary Union?
Authors: Sato Kiyotaka , Zhang Zhaoyong
Published: December 2006

The East Asian region has experienced astonishing economic growth and integration over the past few decades. It is generally believed that a high degree of integration in the region would greatly shape the economic structure of each individual economy and has direct implications for the effectiveness of domestic stabilisation policy and policy coordination. This paper empirically examines the feasibility of forming a monetary union in East Asia by assessing the real output co‐movements among these economies. As suggested by the optimum currency area (OCA) theory that losing monetary independence would be the major cost for adopting a common currency, it would be less costly for the economies to form a monetary union if the business cycles are synchronised across countries. The cointegration test and theVahid and Engle (1993) test for common business cycles are conducted to examine their long‐run relationship and short‐run interactions in real outputs, respectively. Our study found that some pair countries in the region share both the long‐run and short‐run synchronous movements of the real outputs. In particular, the short‐run common business cycles are found in some pairs of ASEAN economies consisting of Singapore, Thailand and Indonesia, and in the Northeast Asian region consisting of Hong Kong, Korea and Mainland China, as well as between Japan and Taiwan. These findings have important implications for the economies in terms of adjustment costs when considering the adoption of a monetary union.
INVESTIGATIONS INTO MECHANISMS RESPONSIBLE FOR SEIZURES INDUCED BY CHLORINATED HYDROCARBON INSECTICIDES: THE ROLE OF BRAIN AMMONIA AND GLUTAMINE IN CONVULSIONS IN THE RAT AND COCKEREL1
Authors: Omer V. St.
Published: December 2006

Abstract— Seizures were produced in adult female rats and in cockerels (Gallus domesticusL.) after the intracarotid administration of four structurally‐unrelated chlorinated hydrocarbon insecticides. The temporal relationship of the course of the convulsions to levels in whole brain of ammonia and glutamine was examined. High levels of brain ammonia occurred in rats and cockerels poisoned acutely with lindane, dieldrin, heptachlor and DDT. The intensity of convulsions and other neurological signs coincided with and were directly correlated with the increases in brain ammonia, whereas interictal periods were associated with decreased levels of ammonia. In both species the order of drug toxicity was lindane > dieldrin > heptachlor > DDT.

Significantly elevated levels of brain glutamine were induced in the cockerels after administration of all four insecticides. In contrast, increased levels of glutamine in rats were found only in those intoxicated with lindane and dieldrin. Although the ammonia‐binding mechanism (conversion of free ammonia into glutamine) was saturated throughout the experiments in both the rats and cockerels, the latter were more resistant to ammonia toxicity by virtue of being able to convert free ammonia into glutamine more efficiently than rats. These data, together with data reported by others, lead to the conclusion that the four structurally‐unrelated chlorinated hydrocarbon insecticides probably induced convulsions in both species by a common mechanism, involving interference with the production and/or utilization of ammonia.
SUBCELLULAR DISTRIBUTION OF CEREBRAL CHOLE‐STANOL IN CEREBROTENDINOUS XANTHOMATOSIS
Authors: Stahl W. L. , Sumi S. M. , Swanson P. D.
Published: December 2006

Abstract— Frozen frontal lobe from a patient with cerebrotendinous xanthomatosis and two control specimens were separated by differential centrifugation into subcellular fractions. The fractions were differentiated by their electron microscopic appearance, by their succinate dehydrogenase and acetylcholinesterase activities and by their galactolipid contents. Free cholestanol was present in largest amounts in the myelin fraction and was also found in each subcellular fraction prepared from the cerebrotendinous xanthomatosis brain. Thus, in this condition, cholestanol storage is a property of myelin and probably also of other brain membranes.
MOVEMENTS OF CALCIUM AND OTHER CATIONS IN ISOLATED CEREBRAL TISSUES1
Authors: Stahl W. L. , Swanson P. D.
Published: December 2006

Abstract— Slices of guinea pig cerebral cortex were incubated in bicarbonate‐ or trisbuffered media. Influx of 45Ca2 +, 54Mn2 +, 133Ba2+ or 90Sr2+ was determined at intervals following addition of the cardiac glycoside, ouabain, to the medium. After incubation for 30 min in the presence of 45Ca2+ and in the absence of ouabain, about 40 per cent of the slice calcium became labelled. Ouabain (01 I″M) markedly increased 45Ca2 + content, as well as the content of unlabelled Ca2 +. Mg2+ and Na+ levels also rose while K+ content dropped at a more rapid rate. Ouabain also brought about increased uptake of 90Sr2+, 133Ba2 + and 54Mn2 +. Lowering the Na+ content of the media prevented the effects of ouabain and brought about an increase in calcium content of brain slices. Addition of 2,4‐dinitrophenol (01 mM) or iodoacetate (1 miu) had slight or moderate effects on 45Ca2+ uptake. The data are most compatible with the presence in cerebral tissue of a sodium‐calcium exchange process.
FREE AMINO ACIDS AND RELATED COMPOUNDS IN BIOPSIES OF HUMAN BRAIN
Authors: Perry T. L. , Hansen S. , Berry K. , Mok C. , Lesk D.
Published: December 2006

Abstract— Contents (μmol/g wet wt.) of 35 free amino acids and related compounds were measured in biopsies of human brain from ten patients. Brain specimens were frozen in liquid nitrogen within 10 sec of their removal at neurosurgery; thus, the values found should approximate those which occur in living brain.

Levels in free pools of biopsied cerebral cortex of most of the amino acids that are constituents of proteins were only 20‐50 per cent of those found in autopsied cortex. The content of cystine and ethanolamine was much lower in biopsied than in autopsied cortex. Concentrations of GABA in biopsied cortex were only 20 per cent as high as those found in autopsied cortex, and levels of γ‐aminobutyryl dipeptides were also significantly lower in biopsied cortex. Amounts of cystathionine in biopsied cortex varied markedly, but averaged much higher than in autopsied cortex; a single biopsy specimen of cerebellar grey matter had a cystathionine content 36‐fold greater than the mean found in autopsied cerebellum.

Appreciable variability in contents among cortical biopsies was found for glycerophosphoethanolamine, phosphoethanolamine, ethanolamine, taurine, aspartic acid, glutamic acid, glutamine, and GABA, as well as for cystathionine. Whether this variability occurred between different subjects, or between different cortical areas, was not clear, although the former possibility was suggested by findings in multiple cortical biopsies from one patient.