bluuebunny/crossref_metadata_2025 huggingface dataset:
Specialist adult physicians in the Top End of the Northern Territory:An analysis of their number and roles
Authors: Weeramanthri Tarun
Published: February 2010

The optimal way of delivering specialist services to rural and remote Australia, andparticularly to remote Aboriginal and Torres Strait Islander communities, is a matterof keen debate at present, and is being considered by the Australian Medical WorkforceAdvisory Committee. This paper contributes to that debate by considering onespecialist medical group, namely adult physicians, and discusses both their role andoptimal number in the Top End of the Northern Territory, in light of the generalworkforce literature and recent changes to the organisation of physician services inthe Northern Territory. Models of specialist service delivery need to be explicit, andorganisational methods transparent, if the service is to be equitable, flexible andaccountable to primary care practitioners.
A new ambulatory classification and funding model for radiation oncology:Non-admitted patients in Victorian hospitals
Authors: Antioch Kathryn M , Walsh Michael K
Published: February 2010

62The Victorian Department of Human Services has developed a classification andfunding model for non-admitted radiation oncology patients. Agencies were previouslyfunded on an historical cost input basis. For 1996?97, payments were made accordingto the new Non-admitted Radiation Oncology Classification System and include fourkey components. Fixed grants are based on Weighted Radiation Therapy Servicestargets for megavoltage courses, planning procedures (dosimetry and simulation) andconsultations. The additional throughput pool covers additional Weighted RadiationTherapy Services once targets are reached, with access conditional on the utilisationof a minimum number of megavoltage fields by each hospital. Block grants coverspecialised treatments, such as brachytherapy, allied health payments and other supportservices. Compensation grants were available to bring payments up to the level of theprevious year. There is potential to provide incentives to promote best practice inAustralia through linking appropriate practice to funding models. Key Australian andinternational developments should be monitored, including economic evaluationstudies, classification and funding models, and the deliberations of the AmericanCollege of Radiology, the American Society for Therapeutic Radiology and Oncology,the Trans-Tasman Radiation Oncology Group and the Council of Oncology Societiesof Australia. National impact on clinical practice guidelines in Australia can beachieved through the Quality of Care and Health Outcomes Committee of theNational Health and Medical Research Council.
The Pharmaceutical Benefits Scheme and the shifting paradigm of welfare policy
Authors: Lofgren Hans
Published: February 2010

This paper describes the design and operation of the Pharmaceutical Benefits Schemeand then proceeds with an analysis of current policy deliberations which identifiesan extension of the market as predominant trend. The paper demonstrates that theconditions which historically sustained the scheme are now present to a lesser extent.The Pharmaceutical Benefits Scheme has functioned as a universalist welfare programwhich conferred onto the Commonwealth Department of Health substantial powersvis-�-vis drug suppliers and professional groups. This position of dominance has beeneroded, with challenges to established arrangements arising, in particular, from theenhanced bargaining position of business and wider pressures operating on theKeynesian welfare state.
The financial impact of anendoluminal stenting procedure
Authors: Mackey Lisa G , Merriel Robert B
Published: February 2010

This paper reports on a study that examined the financial impact of an endoluminalgrafting procedure for an abdominal aortic aneurysm using the Mialhe EndoluminalAortic Stentor. Clinical outcomes were not a focus of this study. The results of the studysuggest that financial impacts of new clinical procedures can be understood andaddressed through planning and greater liaison between clinicians, codingprofessionals and clinical costing staff.
The development of a mental health service patient information management system
Authors: Callaly Tom , Faulkner Peter , Hollis Graeme
Published: February 2010

In this paper we describe the development of the Mental Health-Patient InformationManagement System (MH-PIMS), which is an information management systemdesigned for use in a modern, primarily community-based, mental health service.MH-PIMS is a computerised database which was designed by clinicians and issupported by a case management system and complementary patient record set ?together called the Assessment and Care Evaluation (ACE) system. The paper alsodescribes the ACE system. MH-PIMS can generate patient reports of use to casemanagers and teams in managing their caseloads and is of use to senior cliniciansand service managers for audit and strategic planning purposes.
What precipitates deliberate self-harm?
Authors: Ryan Mark , Parle Michael , Babidge Nick
Published: February 2010

Objective: To develop a working model that provides an understanding of the processof deliberate self-harm and a framework for psychological intervention in anemergency department setting.Method: A retrospective clinical audit of a consecutive series of 51 deliberate self-harmpatients referred to the liaison psychiatry service by the emergency departmentof an inner city hospital.Results: Patient characteristics were diverse. The age range was 17?92 years, with79% between 15 and 35 years. Most were single and unemployed and the majorityhad a psychiatric disorder. Characteristically, there was at least one immediate stressorand intoxication immediately before the attempt.Conclusions: The diversity of deliberate self-harm patients requires strategicintervention in a setting such as the emergency department. The working model forintervention presented here may be transferable to other settings such as generalpractice or community mental health centres using an educational and skillsdevelopment approach with ongoing supervision.
DRGs and inequities among French hospitals: From a new dilemma to another health care policy
Authors: Rodrigues Jean-Marie
Published: February 2010

The unpredictable French health care reform of 1995-96 introduced casemix tools to fund French hospitals at a regional level. After two years (1997-98), health care authorities and hospitals are facing great inequities and inefficiencies (1 to 3) in 22 French regions. Onlyone region (Ile de France, Paris) is above the national casemix index mean, the Index Synthetique d'Activite, and very few are equal to this national mean. The dilemma for most of the 22 regions under this national mean, and within a region like Rhone-Alpes (Saint- Etienne), with inequities from 1 to 2, is to decide whether the main goal of the new health care policy is to reduce inequities and inefficiencies.
Casemix and nursing
Authors: Diers Donna
Published: February 2010

The American Nurses' Association did not embrace the introduction of diagnosis related groups, believing they would not recognise nursing activity nor acuity and would bring about the economic demise of nursing. Australian nurses, by contrast, recognised the window of opportunity that the work towards Australian national diagnosis related groups and funding mechanisms provided to move nursing resources into the political and policy mainstream.This paper reviews the American and Australian nursing experience with casemix, acuity and cost weighting. It uses examples from more recent work to argue for the use of casemix information in new ways, for 'process improvement' or 'evidence-based management'. The paper concludes that the next great leap forward in casemix may require attention to building the information and human infrastructures, so that the valuable clinical-financial information produced by casemix-based information systems can truly inform management and policy.
Booking systems for elective services: The New Zealand experience
Authors: Hefford Benedict , Holmes Andrew
Published: February 2010

This article provides a brief overview of New Zealand's experience in implementing booking systems for elective services in public hospitals. It identifies the basic features of the booking systems policy and explores the rationale and objectives for these policy settings. Progress with implementation of booking systems is explored and some of the challenges and recent developments are also outlined. The authors argue that booking systems represent a major improvement on waiting lists for patients, providers, purchasers and policy-makers.
Budget-holding: The answer to Australian primary care reform?
Authors: Wilton Paula , Smith Richard D
Published: February 2010

In common with other Organisation for Economic Cooperation and Development (OECD)countries, Australia is experiencing growth in expenditure on health care. However, while many other nations continue to pursue some variation of managed competition to address these problems, Australia has chosen a more incremental reform path, with initiatives such as the General Practice Strategy, restrictions in doctor supply and coordinated care trials. This article reviews the likely effectiveness of such initiatives in the light of experience and evidence of budget-holding in achieving similar objectives overseas. It concludes that budget-holding offers a more effective strategy than current 'piecemeal' reforms to contain costs and increase efficiency within Australian health care.
Independent life expectancy in New Zealand, 1996-97
Authors: Tobias Martin , Cheung Jit
Published: February 2010

The objective of this article is to describe independent life expectancy (ILE) in New Zealand in 1996-97, including variations in this indicator between age, gender and ethnic groups. ILE is defined as the number of years a person can expect to live without any self-reported functional limitation requiring the assistance of another person or a complex assistive device. ILE is a positive measure of health. Its complement, expectation of life with dependency(LED), is also a useful indicator. Together, ILE and LED add up to total life expectancy (LE). The contribution to ILE from disability and mortality at each age is analysed in this article.The elasticity of ILE to changes in mortality and to changes in disability is also investigated. Finally, the burden of injury is estimated by calculating the potential gain in ILE that would result were injury-related disability and mortality to be eliminated.
Policy challenges for the Australian health care system
Authors: Duckett Stephen
Published: February 2010

In contrast to the regular media reports decrying the so-called crisis in the health system, anumber of academic commentators have identified areas in which the Australian health caresystem could improve. George Palmer has been one of those, and over the years has publisheda body of work identifying areas for improvement. This paper reviews the performance ofthe Australian health care system against the criteria of equity, efficiency and acceptability,and explicates the contemporary problem areas associated with each criterion.
The role of top management in supporting the use of information technology in Australian hospitals
Authors: Reeve Robert , Rose Graeme
Published: February 2010

The progressive use of information systems and information technology has the potential to transform the way complex organisations are managed and the way they operate. This article reports the findings of a study undertaken to examine the importance of various factors related to the progressive use of information technology in Australian hospitals. Our analysis of data from 84 hospitals shows that hospital size has a significant positive relationship with the progressive use of information technology, as does the chief executive officer's attitude to information technology; however chief executive officer participation in information technology activities does not. The implications of these findings for the role of top management are discussed.
Chaos and pulse packages in current-modulated VCSELs
Authors: Talla Mbé J H , Takougang K S , Woafo P
Published: February 2010

We numerically study the dynamics of vertical cavity surface-emitting lasers (VCSELs) based on the current-dependent gain model subjected to current modulation. For a few hundred MHz frequency of injection current, the threshold current is reduced and polarization switching is accompanied by an anti-phase dynamics of polarization modes. Pulse packages are found and compared with those found in the literature. The behaviour of pulse packages is studied in terms of the modulation parameters. For a few GHz frequency of injection current, the dynamics of VCSELs presents chaotic behaviour.
Rational harmonic balance-based approximate solutions to nonlinear single-degree-of-freedom oscillator equations
Authors: Yamgoué Serge Bruno , Bogning Jean Roger , Kenfack Jiotsa Aurélien , Crépin Kofané Timoléon
Published: February 2010

The purpose of this paper is to extend the application of the modified, generalized, rational harmonic balance method to the determination of approximate analytical solutions to general single-degree-of-freedom oscillator equations. We propose a simple form of rational periodic function that depends on a parameter r such that 0<|r|<1 for the approximating solution. We show how one can determine this parameter analytically as a function of oscillation amplitude for a general nonlinear equation. Three examples are used to demonstrate the procedure and its accuracy.
Can eggs in a cavity be a female secondary sexual signal? Male nest visits and modelling of egg visual discrimination in blue tits
Authors: Holveck Marie-Jeanne , Doutrelant Claire , Guerreiro Romain , Perret Philippe , Gomez Doris , Grégoire Arnaud
Published: February 2010

Eggshell colouration is thought to function as a female-specific secondary sexual trait. While tests of this idea are rapidly accumulating in cavity-nesting birds, some fundamental underlying assumptions remain rarely investigated: namely, can males see eggshell coloration and perceive colour differences between the eggs of different females? We tested these two key assumptions in a natural population of blue tits (
Cyanistes caeruleus
). Using transponders, we tracked male nest visits and found that all males visited their nest-boxes while eggs were present and often visually accessible. Interestingly, some males also visited neighbouring nests. We then tested whether birds could detect eggshell coloration using models of avian colour vision; models were performed with and without limitations on visual performance owing to dim light. Both models found that differences in eggshell brightness were often easier to discriminate than differences in colour; there was more contrast in white eggshell background between clutches than within and its contrast against nest background was repeatable within clutches, suggesting these features could act as signals. Yet, the detectability of these contrasts depended entirely on model assumptions of visual limitations. Consequently, we need a better understanding of underlying visual mechanisms in dim-light environments and behavioural discrimination experiments before confirming the signalling potential of eggshell coloration.
Notonectaexhibit threat-sensitive, predator-induced dispersal
Authors: McCauley Shannon J. , Rowe Locke
Published: February 2010

Dispersal is a central process determining community structure in heterogeneous landscapes, and species interactions within habitats may be a major determinant of dispersal. Although the effects of species interactions on dispersal within habitats have been well studied, how species interactions affect the movement of individuals between habitats in a landscape has received less attention. We conducted two experiments to assess the extent to which predation risk affects dispersal from an aquatic habitat by a flight-capable semi-aquatic insect (Notonecta undulata). Exposure to non-lethal (caged) fish fed conspecifics increased dispersal rates inN. undulata. Moreover, dispersal rate was positively correlated with the level of risk imposed by the fish; the greater the number of notonectids consumed by the caged fish, the greater the dispersal rate from the habitat. These results suggest that risk within a habitat can affect dispersal among habitats in a landscape and thus affect community structure on a much greater scale than the direct effect of predation itself.
Sickness behaviour acting as an evolutionary trap? Male house finches preferentially feed near diseased conspecifics
Authors: Bouwman Karen M. , Hawley Dana M.
Published: February 2010

Host behaviour towards infectious conspecifics is a crucial yet overlooked component of pathogen dynamics. Selection is expected to favour individuals who can recognize and avoid infected conspecifics in order to reduce their own risk of infection. However, evidence is scarce and limited to species employing chemical cues. Here, we experimentally examine whether healthy captive house finches (Carpodacus mexicanus) preferentially forage near a same-sex, healthy conspecific versus one infected with the directly transmissible pathogenMycoplasma gallisepticum(MG), which causes lethargy and visible conjunctivitis. Interestingly, male house finches strongly preferred feeding near diseased conspecifics, while females showed no preference. This sex difference appeared to be the result of lower aggression rates in diseased males, but not in females. The reduced aggression of diseased males may act as an ‘evolutionary trap’ by presenting a historically beneficial behavioural cue in the context of a new environment, which now includes a recently emerged, potentially fatal pathogen. Since MG can be directly transmitted during feeding, healthy males may inadvertently increase their risk of contracting MG. This behaviour is likely to significantly contribute to the continued persistence of MG epidemics in wild populations.
Corrections to the theory and the optimal line in the swimming diagram of Taylor (1952)
Authors: Humphrey Joseph A. C. , Chen Jun , Iwasaki Tetsuya , Otto Friesen W.
Published: February 2010

The analysis of undulatory swimming gaits requires knowledge of the fluid forces acting on the animal body during swimming. In his classical 1952 paper, Taylor analysed this problem using a ‘resistive-force’ theory. The theory was used to characterize the undulatory gaits that result in the smallest energy dissipation to the fluid for a given swim velocity. The optimal gaits thus found were compared with data recorded from movies of a snake and a leech swimming. This report identifies and corrects a mathematical error in Taylor’s paper, showing that his theory applies even better to animals of circular cross section.
A sharp version of Ehrenfest’s theorem for general self-adjoint operators
Authors: Friesecke Gero , Schmidt Bernd
Published: February 2010

We prove the Ehrenfest theorem of quantum mechanics under sharp assumptions on the operators involved.
A new Legendre-type polynomial and its application to geostrophic flow in rotating fluid spheres
Authors: Liao Xinhao , Zhang Keke
Published: February 2010

In rapidly rotating spheres, the whole fluid column, extending from the southern to northern spherical boundary along the rotation axis, moves like a single fluid element, which is usually referred to as geostrophic flow. A new Legendre-type polynomial is discovered in undertaking the asymptotic analysis of geostrophic flow in spherical geometry. Three essential properties characterize the new polynomial: (i) it is a function of
r
and
θ
but takes a single argument

, which is restricted by 0≤
r
≤1 and 0≤
θ
≤
π
, where (
r
,
θ
,
ϕ
) denote spherical polar coordinates with
θ
=0 at the rotation axis; (ii) it is odd and vanishes at the axis of rotation
θ
=0, and (iii) it is defined within—and orthogonal over—the full sphere. As an example of its application, we employ the new polynomial in the asymptotic analysis of forced geostrophic flows in rotating fluid spheres for small Ekman and Rossby numbers. Fully numerical analysis of the same problem is also carried out, showing satisfactory agreement between the asymptotic solution and the numerical solution.
Evolutionary constraints on adaptive evolution during range expansion in an invasive plant
Authors: Colautti Robert I. , Eckert Christopher G. , Barrett Spencer C. H.
Published: February 2010

Biological invasions may expose populations to strong selection for local adaptation along geographical gradients in climate. However, evolution during contemporary timescales can be constrained by low standing genetic variation and genetic correlations among life-history traits. We examined limits to local adaptation associated with northern migration of the invasive wetland plant purple loosestrife (Lythrum salicaria) using a selection model incorporating a trade-off between flowering time and size at reproduction, and common garden experiments of populations sampled along a latitudinal transect of approximately 1200 km in eastern North America. A strong trade-off between flowering time and size at reproduction caused early-flowering plants to be smaller with reduced seed production in northern populations. Northward spread was associated with a decline in genetic variance within populations and an increase in genetic skew for flowering time and size, with limited genetic variation for small, early-flowering genotypes. These patterns were predicted by our selection model of local adaptation to shorter growing seasons and were not consistent with expectations from non-adaptive processes. Reduced fecundity may limit population growth and rates of spread in northern populations. Identifying genetic constraints on key life-history traits can provide novel insights into invasion dynamics and the causes of range limits in introduced species.
Ecological release from interspecific competition leads to decoupled changes in population and individual niche width
Authors: Bolnick Daniel I. , Ingram Travis , Stutz William E. , Snowberg Lisa K. , Lau On Lee , Paull Jeff S.
Published: February 2010

A species's niche width reflects a balance between the diversifying effects of intraspecific competition and the constraining effects of interspecific competition. This balance shifts when a species from a competitive environment invades a depauperate habitat where interspecific competition is reduced. The resulting ecological release permits population niche expansion, via increased individual niche widths and/or increased among-individual variation. We report an experimental test of the theory of ecological release in three-spine stickleback (
Gasterosteus aculeatus
). We factorially manipulated the presence or absence of two interspecific competitors: juvenile cut-throat trout (
Oncorhynchus clarki
) and prickly sculpin (
Cottus asper
). Consistent with the classic niche variation hypothesis, release from trout competition increased stickleback population niche width via increased among-individual variation, while individual niche widths remained unchanged. In contrast, release from sculpin competition had no effect on population niche width, because increased individual niche widths were offset by decreased between-individual variation. Our results confirm that ecological release from interspecific competition can lead to increases in niche width, and that these changes can occur on behavioural time scales. Importantly, we find that changes in population niche width are decoupled from changes in the niche widths of individuals within the population.
A Novel Role for Arabidopsis Mitochondrial ABC Transporter ATM3 in Molybdenum Cofactor Biosynthesis
Authors: Teschner Julia , Lachmann Nicole , Schulze Jutta , Geisler Mirco , Selbach Kristina , Santamaria-Araujo Jose , Balk Janneke , Mendel Ralf R. , Bittner Florian
Published: February 2010

The molybdenum cofactor (Moco) is a prosthetic group required by a number of enzymes, such as nitrate reductase, sulfite oxidase, xanthine dehydrogenase, and aldehyde oxidase. Its biosynthesis in eukaryotes can be divided into four steps, of which the last three are proposed to occur in the cytosol. Here, we report that the mitochondrial ABC transporter ATM3, previously implicated in the maturation of extramitochondrial iron-sulfur proteins, has a crucial role also in Moco biosynthesis. In ATM3 insertion mutants of Arabidopsis thaliana, the activities of nitrate reductase and sulfite oxidase were decreased to ∼50%, whereas the activities of xanthine dehydrogenase and aldehyde oxidase, whose activities also depend on iron-sulfur clusters, were virtually undetectable. Moreover, atm3 mutants accumulated cyclic pyranopterin monophosphate, the first intermediate of Moco biosynthesis, but showed decreased amounts of Moco. Specific antibodies against the Moco biosynthesis proteins CNX2 and CNX3 showed that the first step of Moco biosynthesis is localized in the mitochondrial matrix. Together with the observation that cyclic pyranopterin monophosphate accumulated in purified mitochondria, particularly in atm3 mutants, our data suggest that mitochondria and the ABC transporter ATM3 have a novel role in the biosynthesis of Moco.
Interplay between the NADP-Linked Thioredoxin and Glutathione Systems in Arabidopsis Auxin Signaling
Authors: Bashandy Talaat , Guilleminot Jocelyne , Vernoux Teva , Caparros-Ruiz David , Ljung Karin , Meyer Yves , Reichheld Jean-Philippe
Published: February 2010

Intracellular redox status is a critical parameter determining plant development in response to biotic and abiotic stress. Thioredoxin (TRX) and glutathione are key regulators of redox homeostasis, and the TRX and glutathione pathways are essential for postembryonic meristematic activities. Here, we show by associating TRX reductases (ntra ntrb) and glutathione biosynthesis (cad2) mutations that these two thiol reduction pathways interfere with developmental processes through modulation of auxin signaling. The triple ntra ntrb cad2 mutant develops normally at the rosette stage, undergoes the floral transition, but produces almost naked stems, reminiscent of the phenotype of several mutants affected in auxin transport or biosynthesis. In addition, the ntra ntrb cad2 mutant shows a loss of apical dominance, vasculature defects, and reduced secondary root production, several phenotypes tightly regulated by auxin. We further show that auxin transport capacities and auxin levels are perturbed in the mutant, suggesting that the NTR-glutathione pathways alter both auxin transport and metabolism. Analysis of ntr and glutathione biosynthesis mutants suggests that glutathione homeostasis plays a major role in auxin transport as both NTR and glutathione pathways are involved in auxin homeostasis.
Systematic review: the association between obesity and hepatocellular carcinoma – epidemiological evidence
Authors: SAUNDERS D. , SEIDEL D. , ALLISON M. , LYRATZOPOULOS G.
Published: February 2010

Aliment Pharmacol Ther 31, 1051–1063

Background  Evidence increasingly implicates obesity as an independent risk factor for different cancers. We examined such evidence for hepatocellular carcinoma.

Aim  To review the effect of increased levels of body mass index on hepatocellular carcinoma risk.

Methods  We reviewed systematically the literature examining the association between increased body mass index and hepatocellular carcinoma risk. For each identified study, relevant data were extracted and appraised.

Results  Ten cohort studies (>90 million person‐years), one nested case‐control study (244 cases) and two case‐control studies (494 cases) were identified. Of the cohort studies, 75% of person‐years related to North Americans, 15% to East Asians, and 10% to Europeans. Three cohort studies adjusted for alcohol consumption, only one cohort study adjusted for hepatitis infection status. Seven cohort studies found a positive association between obesity (body mass index ≥30 kg/m2) and hepatocellular carcinoma risk (relative risks ranging from 1.4 to 4.1); two reported no association; and one reported a significant inverse association for a population subgroup (relative risk = 0.7, 95% confidence interval: 0.5–0.9).

Conclusion  Although most studies did not adjust for confounders and most data relate to a single world region, the overall evidence is suggestive of an increased hepatocellular carcinoma risk in obese and overweight individuals.
Single‐point isotope measurements in blood cells and plasma to estimate the time since diet switches
Authors: Klaassen Marcel , Piersma Theunis , Korthals Harry , Dekinga Anne , Dietz Maurine W.
Published: February 2010

1. Understanding ecological phenomena often requires an accurate assessment of the timing of events. To estimate the time since a diet shift in animals without knowledge on the isotope ratios of either the old or the new diet, isotope ratio measurements in two different tissues (e.g. blood plasma and blood cells) at a single point in time can be used. For this ‘isotopic‐clock’ principle, we present here a mathematical model that yields an analytical and easily calculated outcome.

2. Compared with a previously published model, our model assumes the isotopic difference between the old and new diets to be constant if multiple measurements are taken on the same subject at different points in time. Furthermore, to estimate the time since diet switch, no knowledge of the isotopic signature of tissues under the old diet, but only under the new diet is required.

3. The two models are compared using three calibration data sets including a novel one based on a diet shift experiment in a shorebird (red knot Calidris canutus); sensitivity analyses were conducted. The two models behaved differently and each may prove rather unsatisfactory depending on the system under investigation. A single‐tissue model, requiring knowledge of both the old and new diets, generally behaved quite reliably.

4. As blood (cells) and plasma are particularly useful tissues for isotopic‐clock research, we trawled the literature on turnover rates in whole blood, cells and plasma. Unfortunately, turnover rate predictions using allometric relations are too unreliable to be used directly in isotopic‐clock calculations.

5. We advocate that before applying the isotopic‐clock methodology, the propagation of error in the ‘time‐since‐diet‐shift’ estimation is carefully assessed for the system under scrutiny using a sensitivity analysis as proposed here.
Parasites can cause selection against migrants following dispersal between environments
Authors: MacColl Andrew D. C. , Chapman Sonia M.
Published: February 2010

1. The potential for selection against migrants to promote population divergence and speciation is well established in theory, yet there has been relatively little empirical work that has explicitly considered selection against migrants as a form of reproductive barrier, and its importance in the accumulation of reproductive isolation between populations has been overlooked until recently.

2. Parasites often differ between environments and can be an important source of selection on hosts, yet their contribution to population divergence in general, and selection against migrants in particular, is poorly understood.

3. Selection against migrants might be reduced if organisms escape parasitism when they disperse (natural enemy release). Alternatively, parasites could increase selection against migrants if, when they disperse, organisms encounter parasites to which they are poorly adapted.

4. Here we test experimentally the contribution that parasites could make to selection against migrants in the adaptive radiation of three‐spined sticklebacks. These fish have repeatedly colonized freshwater environments from marine ones, and this has repeatedly lead to rapid speciation.

5. We use transplant experiments of lab‐raised fish to simulate dispersal, and antihelminthic treatment to show that ancestral‐type marine sticklebacks contract higher burdens of novel parasites when introduced to freshwater, than in saltwater, and suffer a growth cost as a direct result.

6. Susceptibility to parasites and their detrimental effect is less in derived, freshwater fish from evolutionarily young populations, possibly as a result of selection for resistance.

7. Our results support a role for parasites in selection against migrants and population diversification. They do not support the hypothesis of ‘natural enemy release’.
Characterization of enamel in primary teeth by optical coherence tomography for assessment of dental caries
Authors: MAIA ANA. M. A. , FONSÊCA DÉBORAH D. D. , KYOTOKU BERNARDO B. C. , GOMES ANDERSON S. L.
Published: February 2010

International Journal of Paediatric Dentistry 2010; 20: 158–164

Background.  Caries is a disease that affects both primary and permanent dentitions, therefore new methods of caries diagnosis need to be tested on primary teeth as well as on permanent teeth.

Aim.  This study reports the application of optical coherence tomography (OCT) to characterize sound dental structure and detect natural caries of human primary teeth.

Design.  Six primary teeth were sectioned into thin slices (∼1.5 mm), and analysed perpendicular to the enamel surface by two home‐made OCT systems operating around 1280 and 840 nm. The generated images were compared with histology as the gold standard.

Results.  We demonstrated the efficacy of the OCT technique to measure the depth of the enamel layer, whose result was statistically compared with histology (P = 0.823; P > 0.05) with good agreement. We also determined, through measurement of contrast values, an increase in backscattered intensity of the order of two to three times between sound and caries regions.

Conclusions.  We employed OCT generated images to characterize the enamel layer. The technique showed great potential to be used on paediatric dentistry clinical on early caries detection with no pain, as it is a noninvasive method.
Factors increasing the caries risk of second primary molars in 5‐year‐old Dutch children
Authors: ELFRINK Marlies E. C. , SCHULLER Annemarie A. , VEERKAMP Jaap S. J. , POORTERMAN Jan H. G. , MOLL Henriette A. , Ten CATE Bob (J) M.
Published: February 2010

International Journal of Paediatric Dentistry 2010; 20: 151–157

Background.  Caries is still a prevalent condition in 5‐year‐old children. At present, knowledge regarding some aetiological factors, like deciduous molar hypomineralization (DMH), is limited.

Aim.  To investigate aetiological factors both directly and indirectly associated with caries in second primary molars.

Design.  Of 974 children invited to participate in the study, 386 children were examined clinically with visual detection of caries. Only carious lesions determined to have reached the dentine were recorded. Information about tooth brushing frequency, education level of the mother, and country of birth of mother and child, was collected by means of a multiple‐choice questionnaire. Parents of 452 children filled in the questionnaire. Complete clinical and questionnaire data were available for 242 children. Statistical analysis of the effect of the independent variables was undertaken using the Pearson’s chi‐squared test.

Results.  Deciduous molar hypomineralization (P = 0.02) and the country of birth of the mother (P < 0.001) were positively associated with caries prevalence.

Conclusions.  Deciduous molar hypomineralization and the country of birth of the mother play a role in the prevalence of dental caries. These aetiological factors associated with childhood dental caries need to be investigated further in longitudinal clinical trials.
Trends in dental caries in 1‐ to 4‐year‐old children in a Brazilian city between 1997 and 2008
Authors: BÖNECKER MARCELO , MACHADO ARDENGHI THIAGO , BUTINI OLIVEIRA LUCIANA , SHEIHAM AUBREY , MARCENES WAGNER
Published: February 2010

International Journal of Paediatric Dentistry 2010; 20: 125–131

Objective.  The objective of this study was to assess trends in dental caries prevalence and severity in 1‐ to 4 year‐old children living in Diadema, Brazil, over a 11‐year period, from 1997 to 2008.

Methods.  In 2008 an epidemiological oral health survey was carried out and the results on caries were compared with five cross‐sectional studies carried out using the same methods and criteria in 1997, 1999, 2002, 2004, and 2006 in the same city. In all surveys, children were randomly selected from those attending a National Day of Children’s Vaccination. Calibrated dentists carried out the clinical examination using WHO criteria. Caries trends were assessed by time‐lag analysis. In total, 5348 children were examined in the six surveys over the 11‐year period.

Results.  Time‐lag analysis showed a marked and statistically significant decline in the prevalence (χ2 for trends: P < 0.001) and severity (Kruskal–Wallis: P < 0.001) of dental caries between 1997 and 2008.

Conclusion.  In conclusion, the last cohort of preschool children in Diadema had much better dental caries status than those in 1997.
Dentinogenesis imperfecta in children with osteogenesis imperfecta: a clinical and ultrastructural study
Authors: MAJORANA ALESSANDRA , BARDELLINI ELENA , BRUNELLI PIER CARLO , LACAITA MARIAGRAZIA , CAZZOLLA ANGELA PIA , FAVIA GIANFRANCO
Published: February 2010

International Journal of Paediatric Dentistry 2010; 20: 112–118

Aim.  The aim of this study was to assess the correlation between osteogenesis imperfecta (OI) and dentinogenesis imperfecta (DI) from both a clinical and histological point of view, particularly clarifying the structural and ultrastructural dentine changes.

Design.  Sixteen children (6–12 years aged) with diagnosis of OI were examined for dental alterations referable to DI. For each patient, the OI type (I, III, or IV) was recorded. Extracted or normally exfoliated primary teeth were subjected to a histological examination (to both optical microscopy and confocal laser‐scanning microscopy).

Results.  A total of ten patients had abnormal discolourations referable to DI: four patients were affected by OI type I, three patients by OI type III, and three patients by OI type IV. The discolourations, yellow/brown or opalescent grey, could not be related to the different types of OI. Histological exam of primary teeth showed severe pathological change in the dentin, structured into four different layers. A collagen defect due to odontoblast dysfunction was theorized to be on the base of the histological changes.

Conclusions.  There is no correlation between the type of OI and the type of discolouration. The underlying dentinal defect seems to be related to an odontoblast dysfunction.
Density as an explanatory variable of movements and calf survival in savanna elephants across southern Africa
Authors: Young K. D. , Van Aarde R. J.
Published: February 2010

1. Southern Africa’s ‘elephant problem’ is often attributed to an overabundance of elephants (Loxodonta africana) in conservation areas. Paradoxically, the African elephant is listed as ‘vulnerable’ (IUCN Redlist) despite occupying a large geographical range and numbering about 600 000. How densities influence elephant populations is therefore important for conservation management decisions, particularly because a move towards non‐equilibrium management of savannas implies a need for elephant populations to fluctuate in response to variation in intrinsic (demographic) and extrinsic (resource) factors.

2. A study on one of the world’s largest elephant populations demonstrated that population regulation is driven by a spatial response to water availability, environmental stochasticity and density. The challenge remains to identify the demographic and behavioural variables that drive density dependence.

3. We evaluated whether the movements of elephant family groups from 13 populations across a wide resource gradient were explained by variability in primary productivity, rainfall and population density. We then assessed whether density‐related movements explained variability in juvenile survival, hence inferring a spatially driven behavioural mechanism that may explain density‐dependent population growth. We also analysed whether management actions modified this mechanism.

4. In the dry season, daily‐displacement distances (DDDs) increased non‐linearly with density, and declined with increased vegetation productivity and previous wet season rainfall. In the wet season, DDDs were primarily explained by vegetation productivity.

5. The survival of weaned calves (4–7 years) decreased with increasing dry season DDDs, but this did not hold for suckling calves (1–3 years) or sub‐adults (8–11 years).

6. Fences and supplementary water modified the shape and strength of relationships between DDDs and densities, vegetation productivity and rainfall and negated the relationships between DDDs and weaned calf survival.

7. We suggest that density dependence in weaned calf survival is driven by the response of dry season roaming activities of family groups to variations in density, rainfall and the distribution of food. Fences and supplementary water that alter this mechanism may contribute to the relatively high population growth rates of some populations.
A phylogeographical study of the toxic benthic dinoflagellate genus Ostreopsis Schmidt
Authors: Penna Antonella , Fraga Santiago , Battocchi Cecilia , Casabianca Silvia , Giacobbe Maria Grazia , Riobó Pilar , Vernesi Cristiano
Published: February 2010

Aim  Ostreopsis is a benthic and epiphytic dinoflagellate producing potent toxins widespread in tropical and warm temperate coastal areas world‐wide. We tested the hypothesis that as it is benthic, it would show distinct biogeographical patterns in comparison with planktonic species. Here, we analyse sequence variability in ribosomal DNA markers to provide the first phylogeographical study of this toxic benthic dinoflagellate.

Location  Mediterranean Sea, Atlantic Ocean, Pacific Ocean.

Methods  Ribosomal DNA sequence data from partial nuclear LSU (D1/D2 domains) and 5.8S genes and non‐coding internal transcribed spacer (ITS) regions were obtained from 82 isolates of Ostreopsis species, collected at 26 localities throughout the world. Molecular sequence data were analysed using maximum parsimony, maximum likelihood and Bayesian methods for phylogenetic inference. A statistical parsimony network was obtained based on concatenated LSU and 5.8S rDNA–ITS region sequences of the Mediterranean/Atlantic Ostreopsis cf. ovata isolates to infer haplotype distribution over their geographical range. Light epifluorescence microscopy analyses were performed on cultured and field Ostreopsis material for taxonomic identification, while laboratory experiments for encystment induction were carried out on selected O. cf. ovata isolates. Toxin assays of Ostreopsis species isolates were carried out using the haemolytic‐based method.

Results  Analyses based on single and concatenated ribosomal genes gave substantially similar results. The rDNA phylogeny revealed different clades corresponding to different species within the genus Ostreopsis. In the species O. cf. ovata, different genetic lineages were correlated with macrogeographical distribution. A network of haplotypes inferred from the Atlantic and Mediterranean isolates of O. cf. ovata revealed that these two areas might host a single panmictic population. The Atlantic/Mediterranean population of O. cf. ovata was differentiated considerably from the Indo‐Pacific populations. Other species of Ostreopsis were found, but they turned out to be restricted to just one of the two main warm‐water oceanic basins, the Mediterranean/Atlantic and the Indo‐Pacific.

Main conclusions  Ostreopsis cf. ovata was found to be widely dispersed throughout the coastal areas of tropical and some warm temperate seas. In the Atlantic/Mediterranean region it may constitute a panmictic population that is highly distinct from Indo‐Pacific populations. Ostreopsis cf. siamensis was found only in the Mediterranean Sea, and strains identified as Ostreopsis lenticularis and Ostreopsis labens were found only in the Indo‐Pacific region.
Lessepsian fish migration: genetic bottlenecks and parasitological evidence
Authors: Merella Paolo , Casu Marco , Garippa Giovanni , Pais Antonio
Published: February 2010

As a rule, non‐indigenous species (NIS) populations derived from biological invasion events represent a subset of the genetic diversity of the source population. In biological invasions, host–parasite interactions play an important role, and parasitological data for NIS populations can provide useful information such as their area of origin, mechanism of invasion and prospects of success in the new habitat. When both genetic and parasitological data are available, and they suggest the same scenario, the history of an invasion can be inferred with no discrepancy, but when data cannot be reconciled an alternative model should be considered. In this study a comparison of genetic and parasitological data for the Lessepsian migrant the bluespotted cornetfish, Fistularia commersonii, in the Mediterranean Sea presents the opportunity to evaluate the compatibility of information of this nature, and to propose possible invasion scenarios consistent with evidence provided by both criteria.
A dual role of extracellular DNA during biofilm formation of Neisseria meningitidis
Authors: Lappann Martin , Claus Heike , Van Alen Tessa , Harmsen Morten , Elias Johannes , Molin Søren , Vogel Ulrich
Published: February 2010

Major pathogenic clonal complexes (cc) of Neisseria meningitidis differ substantially in their point prevalence among healthy carriers. We show that frequently carried pathogenic cc (e.g. sequence type ST‐41/44 cc and ST‐32 cc) depend on extracellular DNA (eDNA) to initiate in vitro biofilm formation, whereas biofilm formation of cc with low point prevalence (ST‐8 cc and ST‐11 cc) was eDNA‐independent. For initial biofilm formation, a ST‐32 cc type strain, but not a ST‐11 type strain, utilized eDNA. The release of eDNA was mediated by lytic transglycosylase and cytoplasmic N‐acetylmuramyl‐l‐alanine amidase genes. In late biofilms, outer membrane phospholipase A‐dependent autolysis, which was observed in most cc, but not in ST‐8 and ST‐11 strains, was required for shear force resistance of microcolonies. Taken together, N. meningitidis evolved two different biofilm formation strategies, an eDNA‐dependent one yielding shear force resistant microcolonies, and an eDNA‐independent one. Based on the experimental findings and previous epidemiological observations, we hypothesize that most meningococcal cc display a settler phenotype, which is eDNA‐dependent and results in a stable interaction with the host. On the contrary, spreaders (ST‐11 and ST‐8 cc) are unable to use eDNA for biofilm formation and might compensate for poor colonization properties by high transmission rates.