bluuebunny/crossref_metadata_2025 huggingface dataset:
Geographic and annual variation in reproductive cycles in the Tasmanian spotted snow skink, Niveoscincus ocellatus (Squamata : Scincidae)
Authors: Wapstra Erik , Swain Roy , Jones Susan M. , O'Reilly Julianne
Published: January 2006

We studied the reproductive cycle of two populations of the spotted snow
skink, Niveoscincus ocellatus, over a three-year period.
This species is widespread in Tasmania and its distribution overlaps those of
other species in the genus that show two distinct reproductive strategies:
annual reproduction that is completed within one season, and biennial
reproduction in which females carry advanced embryos throughout winter
hibernation. We chose populations representative of the climatic extremes of
the species’ distribution, within these areas of overlap.
Niveoscincus ocellatus maintains the same basic
reproductive strategy in both populations: summer gestation, primary autumn
mating with obligate sperm storage by females, secondary mating in spring, and
predominantly spring vitellogenesis and ovulation. In both populations all
females reproduce annually, suggesting that reproductive frequency is not
constrained by availability of energy. However, we found distinct differences
in the timing of ovulation and parturition. Females from our subalpine site
ovulated approximately one month later than those from our warmer, lowland
site; parturition was delayed by the same period so gestation length was
unchanged. The delay in ovulation results in gestation proceeding over the
warmest months at the cold site. The annual reproductive cycle of this species
appears to constrain its distribution to the lower altitudinal/climatic
range of alpine Niveoscincus species. There were minor
annual differences in the timing of reproductive events at each site, which we
attribute to variation in thermal conditions and the amount of precipitation.
Impact of an Infection Control Program in an Intensive Care Unit in France
Authors: Verdier Régis , Parer Sylvie , Jean-Pierre Hélène , Dujols Pierre , Picot Marie-Christine
Published: January 2006

Objective.

To evaluate the impact of an infection control program in an intensive care unit (ICU).

Design.

Prospective before-after study. Two 6-month study periods were compared; between these periods, an infection control program based on isolation was implemented.

Setting.

Polyvalent ICU of Montpellier Teaching Hospital.

Patients.

Any patient who was hospitalized in the ICU for >48 hours and was discharged during 1 of the 2 periods.

Main Outcome Measures.

The main patient-related variables were sex, age at admission, type of patient (surgical, medical, or trauma), Simplified Acute Physiology Score II, length of ICU stay, need for intubation, duration of exposure to invasive devices, onset of nosocomial infection and pathogens responsible, and death. We compared the 2 study periods with respect to the incidence of 4 nosocomial infections (pneumonia, urinary tract infection, bacteremia, and catheter-associated infection), the frequency of infection with the main multidrug-resistant pathogens, and patient survival.

Results.

Patients in periods 1 and 2 were similar with regard to sex, age, physiology score, and exposure to invasive devices. The rates of infection with multidrug-resistant pathogens were significandy lower during period 2 than during period 1 (infection rate: 28.1% of patients in period 1 and 9.6% of patients in period 2 [P = .01]; pneumonia rate: 32.6% of patients in period 1 and 4.2% of patients in period 2 [P = .008]). The mortality rate among patients with nosocomial pneumonia was 38.2% in period 1 and 4.3% in period 2 (P = .009).

Conclusions.

After implementation of an infection control program, the rate of infection with multidrug-resistant pathogens decreased, as did the mortality rate among patients with nosocomial pneumonia.
A Prospective Trial of a Novel, Silicone-Based, Silver-Coated Foley Catheter for the Prevention of Nosocomial Urinary Tract Infections
Authors: Srinivasan Arjun , Karchmer Tobi , Richards Ann , Song Xiaoyan , Perl Trish M.
Published: January 2006

Objective.

To evaluate the efficacy of silicone-based, silver ion–impregnated urinary catheters in the prevention of nosocomial urinary tract infections (NUTIs).

Design.

Prospective, crossover study to compare the efficacy of a silicone-based, hydrogel-coated, silver-impregnated Foley catheter with that of a silicone-based, hydrogel-coated catheter in the prevention of NUTIs.

Setting.

Adult medical and surgical wards of a university teaching hospital.

Results.

A total of 3,036 patients with catheters were evaluated; 1,165 (38%) of the catheters were silver impregnated, and 1,871 (62%) were not silver impregnated. Study groups were not identical; there were more men, a shorter duration of catheterization, and fewer urine cultures per 1,000 catheter-days in the silver catheter group. The rate of NUTIs per 1,000 Foley-days was 14.29 in the silver catheter group, compared with 16.15 in the nonsilver catheter group (incidence rate ratio, 0.88; 95% confidence interval, 0.70-1.11;P= .29). The median length of catheterization prior to the onset of a urinary tract infection (ie, exposure time) was 4 days for each group. There were no differences in the recovery of gram-positive, gram-negative, or fungal organisms in NUTIs. In a multivariate survival analysis, no factors, including silver catheters, were protective against NUTI.

Conclusions.

Unlike previous trials of latex-based, silver ion–impregnated Foley catheters, we found that silicone-based, silver-impregnated Foley catheters were not effective in preventing NUTIs; however, this study was affected by differences in the study groups. Prospective trials remain important in assessing the efficacy and cost-effectiveness of new silver-coated products.
Low Prevalence of Pertussis Among Children Admitted With Respiratory Symptoms During Respiratory Syncytial Virus Season
Authors: Siberry George K. , Paquette Nicholas R. , Ross Tracy L. , Perl Trish M , Valsamakis Alexandra
Published: January 2006

Pertussis may go unrecognized during respiratory syncytial virus (RSV) epidemics. Nosocomially transmitted pertussis can be severe in infants. Polymerase chain reaction (PCR) screening may identify infants with pertussis on admission, allowing for preemptive isolation. In a random sample, 1 (0.6%) of 166 children admitted to the hospital during RSV season were Bordetella pertussis PCR positive during a nonepidemic period. These data show that screening may not be useful when pertussis prevalence is low.
Knowledge About HIV Infection and Attitude of Nursing Staff Toward Patients With AIDS in Iran
Authors: Askarian Mehrdad , Hashemi Zohreh , Jaafari Peyman , Assadian Ojan
Published: January 2006

Background.

Although adequate knowledge about HIV infection and effective antitransmission measures, such as taking universal precautions in the handling of blood and other body fluids, are important factors in minimizing the risk of HIV transmission in the healthcare setting, little has been reported on the knowledge of nurses with regard to HIV infection and their attitude toward patients with AIDS in Iran. The aim of the present study was to assess these matters.

Methods.

A questionnaire-based cross-sectional study was conducted from March to April 2003. Included were 1098 nursing staff (registered nurses, registered midwives, and auxiliary nurses) from 8 university teaching hospitals affiliated with the Shiraz University of Medical Sciences.

Results.

Registered nurses and midwives had a significantly higher level of knowledge about HIV infection than did auxiliary nurses (χ2 = 16.4; df = 1; P<.001). With regard to the causative agent of AIDS, nurses holding a bachelor of science in nursing or a master of science in nursing (MSN) had a significantly higher level of knowledge than did auxiliary nurses (χ2 = 18.6; df = 1; P<.001). Women more often answered correctly that it is not possible to identify HIV-infected patients by their appearance during the early stages of disease than did men (χ2 = 17.52; df= 1; P<.001). Although 50.7% of respondents had previously cared for patients with AIDS and 54.3% had participated in education programs on AIDS, nearly half stated that they would not want to have to care for patients with AIDS and that, if assigned to care for such a patient, they would ask to be assigned elsewhere.

Conclusions.

Our finding that those who scored best on the questionnaire were midwives and single female nurses holding an MSN who had previously cared for HIV-infected patients scored best might indicate that use of selective education campaigns is the most suitable education strategy. The effectiveness of targeted education programs on HIV/AIDS should be repeatedly evaluated in the future.
Increased Influenza Vaccination of Healthcare Workers at a Pediatric Cancer Hospital: Results of a Comprehensive Influenza Vaccination Campaign
Authors: McCullers Jonathan A. , Speck Kathleen M. , Williams Bonnie F. , Liang Hua , Mirro Joseph
Published: January 2006

A comprehensive influenza vaccination campaign improved vaccination rates among healthcare workers with direct patient care responsibilities from 45% during the 2003-2004 influenza season to 80% during the 2004-2005 season. A strategy of weekly feedback to unvaccinated employees was the most important factor in enhancing the rate of vaccination acceptance and was particularly effective among the nursing staff.
Disinfection of Needleless Catheter Connectors and Access Ports With Alcohol May Not Prevent Microbial Entry: The Promise of a Novel Antiseptic-Barrier Cap
Authors: Menyhay Steve Z. , Maki Dennis G.
Published: January 2006

Background.

Needleless valve connectors for vascular catheters are widely used throughout the United States because they reduce the risk of biohazardous injuries from needlesticks and exposure to bloodborne pathogens, such as human immunodeficiency virus and hepatitis C virus. Patients with long-term central venous catheters are at significant risk of acquiring catheter-related bloodstream infections caused by microbes that gain access through the connection between the administration set and the catheter or an injection port. Most healthcare practitioners wipe the membranous septum of the needleless connector or the injection port with 70% alcohol before accessing it. We report a simulation study of the efficacy of conventional alcohol disinfection before access, compared with that of a novel antiseptic-barrier cap that, when threaded onto a needleless luer-activated valved connector, allows a chlorhexidine-impregnated sponge to come into continuous contact with the membranous surface; after removal of the cap, there is no need to disinfect the surface with alcohol before accessing it.

Methods.

One hundred five commercial, needleless luer-activated valved connectors, each accessible by a blunt male-connector luer-lock attachment, were purchased from 3 manufacturers and were tested. The membranous septum of each test device was first heavily contaminated with ~105colony-forming units ofEnterococcus faecalisand then was allowed to dry for 24 hours. Fifteen of the contaminated devices were not disinfected (positive controls), 30 were conventionally disinfected with a commercial 70% alcohol pledget, and 60 had the antiseptic cap threaded onto the connector and then removed after 10 minutes. The test connectors were then accessed with a sterile syringe containing nutrient broth media, which was injected, captured on the downstream side of the intraluminal fluid pathway, and cultured quantitatively.

Results.

All 15 control connectors (100%) showed massive transmission of microorganisms across the membranous septum (4,500-10,000 colony-forming units). Of the 30 connectors accessed after conventional disinfection with 70% alcohol, 20 (67%) showed transmission of microorganisms (442-25,000 colony-forming units). In contrast, of the 60 connectors cultured after application of the novel antiseptic cap, only 1 (1.6%) showed any transmission of microorganisms (P<.001).

Conclusions.

The findings of this study show that, if the membranous septum of a needleless luer-activated connector is heavily contaminated, conventional disinfection with 70% alcohol does not reliably prevent entry of microorganisms. In contrast, the antiseptic-barrier cap provided a high level of protection, even in the presence of very heavy contamination. This novel technology deserves to be studied in a clinical trial.
Staphylococcus aureusBloodstream Infection After Cardiac Surgery: Risk Factors and Outcome
Authors: Olsson Christian , Tammelin Ann , Thelin Stefan
Published: January 2006

Thirty-eight patients (10 cases and 28 controls) were included in a case-control study ofStaphylococcus aureusbloodstream infection after cardiac surgery in 833 patients. All bacterial strains were found to be unique by pulsed-field gel electrophoresis. In multivariable risk-factor analysis, only valve prosthesis implantation was associated with blood-stream infection. The early and late case mortality rate was 0%.
An Outbreak of Pertussis in a Hematology-Oncology Care Unit: Implications for Adult Vaccination Policy
Authors: Boulay Brian R. , Murray Carolyn J. , Ptak Judy , Kirkland Kathryn B. , Montero Jose , Talbot Elizabeth A.
Published: January 2006

A pertussis outbreak in a hematology-oncology care unit involved 10 (8.5%) of 117 employees. The source was an employee who contracted pertussis via a family contact. No screened patients contracted pertussis, likely because of isolation measures. Hospitals should consider employee immunization with acellular vaccine in healthcare settings where pertussis has high rates of morbidity and mortality.
Quantifying the gender load: can population crosses reveal interlocus sexual conflict?
Authors: Long Tristan A.F , Montgomerie Robert , Chippindale Adam K
Published: January 2006

Six sister populations ofDrosophila melanogasterkept under identical environmental conditions for greater than 600 generations were reciprocally crossed to investigate the incidence of population divergence in allopatry. Population crosses directly influenced fitness, mating frequency, and sperm competition patterns. Changes in both female remating rate and the outcome of male sperm competition (P1, P2) in response to foreign males were consistent with intersexual coevolution. Moreover, seven of the 30 crosses between foreign mates resulted in significant reductions in female fitness, whereas two resulted in significant increases, compared to local matings. This tendency for foreign males to reduce female fitness may be interpreted as evidence for either sexually antagonistic coevolution or the disruption of mutualistic interactions. However, instances in which female fitness improved via cohabitation with foreign males may better reveal sexual conflict, signalling release from the cost of interacting with locally adapted males. By this metric, female reproduction inD. melanogasteris strongly constrained by local adaptation by males, a situation that would promote antagonistic coevolution between the sexes. We conclude that sexual selection can promote population differentiation in allopatry and that sexual conflict is likely to have played a role in population differentiation in this study system.
Detecting sexual conflict and sexually antagonistic coevolution
Authors: Rowe Locke , Day Troy
Published: January 2006

We begin by providing an operational definition of sexual conflict that applies to both inter- and intralocus conflict. Using this definition, we examine a series of simple coevolutionary models to elucidate fruitful approaches for detecting interlocus sexual conflict and resultant sexually antagonistic coevolution. We then use published empirical examples to illustrate the utility of these approaches. Three relevant attributes emerge. First, the dynamics of sexually antagonistic coevolution may obscure the conflict itself. Second, competing models of inter-sexual coevolution may yield similar population patterns near equilibria. Third, a variety of evolutionary forces underlying competing models may be acting simultaneously near equilibria. One main conclusion is that studies of emergent patterns in extant populations (e.g. studies of population and/or female fitness) are unlikely to allow us to distinguish among competing coevolutionary models. Instead, we need more research aimed at identifying the forces of selection acting on shared traits and sexually antagonistic traits. More specifically, we need a greater number of functional studies of female traits as well as studies of the consequences of both male and female traits for female fitness. A mix of selection and manipulative studies on these is likely the most promising route.
Trauma, disease and collateral damage: conflict in cimicids
Authors: Siva-Jothy M.T
Published: January 2006

The bed bugs and bat bugs (Hemiptera: Cimicidae) are unusual in being a gonochorist (separate male and female genders) taxon with obligate traumatic insemination. Males of all the species in this family have a lanceolate paramere (intromittent organ) which they use to pierce the female's body wall and inseminate directly into her haemocoel, despite the presence of a functional female genital tract. Mating is tightly linked to the feeding cycle inCimex lectularius, the common bed bug. In this paper, I examine key aspects of the reproductive anatomy and behaviour ofC. lectulariusthat underpin the nature of the conflict over mating rate in this species. I then examine the consequences of traumatic insemination for female fitness and examine potential mechanisms that might underpin those costs. Finally, the collateral consequences of the male reproductive tactic on other males ofC. lectulariusand the African bat bug,Afrocimex constrictusare examined.
Sensory exploitation and sexual conflict
Authors: Arnqvist Göran
Published: January 2006

Much of the literature on male–female coevolution concerns the processes by which male traits and female preferences for these can coevolve and be maintained by selection. There has been less explicit focus on the origin of male traits and female preferences. Here, I argue that it is important to distinguish origin from subsequent coevolution and that insights into the origin can help us appreciate the relative roles of various coevolutionary processes for the evolution of diversity in sexual dimorphism. I delineate four distinct scenarios for the origin of male traits and female preferences that build on past contributions, two of which are based on pre-existing variation in quality indicators among males and two on exploitation of pre-existing sensory biases among females. Recent empirical research, and theoretical models, suggest that origin by sensory exploitation has been widespread. I argue that this points to a key, but perhaps transient, role for sexually antagonistic coevolution (SAC) in the subsequent evolutionary elaboration of sexual traits, because (i) sensory exploitation is often likely to be initially costly for individuals of the exploited sex and (ii) the subsequent evolution of resistance to sensory exploitation should often be associated with costs due to selective constraints. A review of a few case studies is used to illustrate these points. Empirical data directly relevant to the costs of being sensory exploited and the costs of evolving resistance is largely lacking, and I stress that such data would help determining the general importance of sexual conflict and SAC for the evolution of sexual dimorphism.
Sexual conflict and the alternation of haploid and diploid generations
Authors: Haig David , Wilczek Amity
Published: January 2006

Land plants possess a multicellular diploid stage (sporophyte) that begins development while attached to a multicellular haploid progenitor (gametophyte). Although the closest algal relatives of land plants lack a multicellular sporophyte, they do produce a zygote that grows while attached to the maternal gametophyte. The diploid offspring shares one haploid set of genes with the haploid mother that supplies it with resources and a paternal haploid complement that is not shared with the mother. Sexual conflict can arise within the diploid offspring because the offspring's maternal genome will be transmitted in its entirety to all other sexual and asexual offspring that the mother may produce, but the offspring's paternally derived genes may be absent from these other offspring. Thus, the selective forces favouring the evolution of genomic imprinting may have been present from the origin of modern land plants. In bryophytes, where gametophytes are long-lived and capable of multiple bouts of asexual and sexual reproduction, we predict strong sexual conflict over allocation to sporophytes. Female gametophytes of pteridophytes produce a single sporophyte and often lack means of asexual reproduction. Therefore, sexual conflict is predicted to be attenuated. Finally, we explore similarities among models of mate choice, offspring choice and segregation distortion.
Effect of protracted treatment with rosiglitazone, a PPARγ agonist, in patients with Cushing's disease
Authors: Giraldi Francesca Pecori , Scaroni Carla , Arvat Emanuela , De Martin Martina , Giordano Roberta , Albiger Nora , Leao Adriana A. S. , Picu Andreea , Mantero Franco , Cavagnini Francesco
Published: January 2006

Objective  Cushing's disease, hypercortisolism due to a pituitary ACTH‐secreting tumour, is a highly morbid illness as yet without effective medical therapy. Recent studies have demonstrated that peroxisome proliferator‐activated receptor gamma (PPARγ) agonists effectively suppress ACTH secretion in a murine tumoral corticotroph cell line, but the few studies conducted so far in patients with ACTH‐secreting pituitary adenomas have yielded variable results.

Design  Ten patients with Cushing's disease were treated with 4–16 mg rosiglitazone p.o. daily for 1–8 months (median 3 months) and plasma ACTH and cortisol, urinary free cortisol (UFC), as well as parameters of insulin sensitivity, were recorded. An acute challenge with 8 mg rosiglitazone for 2 days preceded long‐term rosiglitazone administration.

Results  The acute challenge with rosiglitazone did not significantly modify plasma ACTH and cortisol levels. During protracted treatment with rosiglitazone, four patients showed a persistent reduction in UFC levels (up to 24% of pretreatment values), achieving normalization in three. In the others, UFC as well as plasma ACTH and cortisol decrements were inscribed within wide, random oscillations indicating that disease activity was substantially unchanged. Insulin sensitivity was ameliorated in most patients, without relation to ACTH or cortisol secretion. Untoward effects, such as weight gain, oedema and worsening of ecchymoses, were reported in several patients.

Conclusions  Although effective in a subset of patients, protracted rosiglitazone administration did not consistently restrain ACTH and cortisol secretion in patients with Cushing's disease. Further investigations are needed to fully define the therapeutic potential of PPARγ agonists in this disorder.
Application of a variance decomposition method to compare satellite and aerial inventory data: a tool for evaluating wildlife–habitat relationships
Authors: BROWN G. S. , RETTIE W. J. , MALLORY F. F.
Published: January 2006

Researchers frequently rely on forest inventories derived for other purposes when characterizing wildlife–habitat associations. When studied populations are remote and inventory coverage is incomplete for one or more data sets, researchers must often choose between the need for greater detail in habitat information and complete coverage of the land base. Forest inventories are often limited to canopy‐level information; however, different aspects of the overstorey and understorey may be important to wildlife.

We compared the explanatory power of a forest resource inventory (FRI) and Landsat‐derived inventory to account for variation in vegetation communities available to woodland caribou Rangifer tarandus caribou. Forest canopy and understorey data were collected from stands in the Clay Belt region of Ontario, Canada, and cluster analysis and ordination were used to identify discrete community types.

Canonical correspondence analysis revealed strong relationships between forest inventories and vegetation communities derived from field data. The integration of field‐based species and structural data with remote sensing land cover information provided sufficient detail among vegetation communities to identify features of known importance to woodland caribou. Variance decomposition revealed that FRI and Landsat variables had different capacities to explain variation in community composition, and overlap existed in the explanatory power. FRI species factors had greater explanatory power than Landsat habitat classes; however, Landsat structural variables accounted for more variation than FRI structural variables.

Synthesis and applications. The results support the use of forest inventory attributes to infer vegetation characteristics in the overstorey and understorey, thus providing a tool for wildlife–habitat management. The need to account for woodland caribou habitat needs in forest management planning can be facilitated by using readily available vegetation descriptions within the FRI and Landsat data sets. This approach to community classification is of particular benefit for characterizing wildlife habitat in remote areas where collection of detailed vegetation information is impractical. When using habitat inventories derived from different data sources, variance decomposition can aid the researcher in identifying how explanatory power is structured within different data sets, quantifying the independent and confounded components of explained variation.
Assessing river biotic condition at a continental scale: a European approach using functional metrics and fish assemblages
Authors: PONT D. , HUGUENY B. , BEIER U. , GOFFAUX D. , MELCHER A. , NOBLE R. , ROGERS C. , ROSET N. , SCHMUTZ S.
Published: January 2006

The need for sensitive biological measures of aquatic ecosystem integrity applicable at large spatial scales has been highlighted by the implementation of the European Water Framework Directive. Using fish communities as indicators of habitat quality in rivers, we developed a multi‐metric index to test our capacity to (i) correctly model a variety of metrics based on assemblage structure and functions, and (ii) discriminate between the effects of natural vs. human‐induced environmental variability at a continental scale.

Information was collected for 5252 sites distributed among 1843 European rivers. Data included variables on fish assemblage structure, local environmental variables, sampling strategy and a river basin classification based on native fish fauna similarities accounting for regional effects on local assemblage structure. Fifty‐eight metrics reflecting different aspects of fish assemblage structure and function were selected from the available literature and tested for their potential to indicate habitat degradation.

To quantify possible deviation from a ‘reference condition’ for any given site, we first established and validated statistical models describing metric responses to natural environmental variability in the absence of any significant human disturbance. We considered that the residual distributions of these models described the response range of each metric, whatever the natural environmental variability. After testing the sensitivity of these residuals to a gradient of human disturbance, we finally selected 10 metrics that were combined to obtain a European fish assemblage index. We demonstrated that (i) when considering only minimally disturbed sites the index remains invariant, regardless of environmental variability, and (ii) the index shows a significant negative linear response to a gradient of human disturbance.

Synthesis and applications. In this reference condition modelling approach, by including a more complete description of environmental variability at both local and regional scales it was possible to develop a novel fish biotic index transferable between catchments at the European scale. The use of functional metrics based on biological attributes of species instead of metrics based on species themselves reduced the index sensitivity to the variability of fish fauna across different biogeographical areas.
Effects of the Nd:YAG laser, air‐abrasion, and acid‐etchant on filling materials
Authors: TÜRKMEN C. , SAZAK H. , GÜNDAY M.
Published: January 2006

summary  The purpose of this study was to determine any inadvertent effects of the neodymium: yttrium–aluminium–garnet (Nd:YAG) laser, air‐abrasion, and ortho‐phosphoric acid on some conventionally used dental filling materials [amalgam, composite resin, compomer, glass–ionomer cement (GIC), and ceromer], when they were used for purposes of margin etching and assessed according to standard enamel etching parameters using a total of five fillings. The surfaces of the filling materials were polished. One sample from each material group was exposed to laser (at 0·75 J, 15 pps) and air abrasion (with Al‐oxide powder, 60 psi) for 2 s and to the 37% ortho‐phosphoric acid for 60 s. The exposed materials were examined under Scanning Electron Microscopy (SEM). After laser treatment most specimens showed recrystallized areas, the GIC surface being the most affected. There were some pores and cavities on the amalgam surface following laser treatment. The abraded surfaces showed mechanical abrasions. The acid etchant showed the least effect. During the application of laser or air‐abrasion, the adjacent tooth or filling surface must be protected or the dentist must be careful.
A new approach to define defect extensions of endodontically treated teeth: inter‐ and intra‐examiner reliability
Authors: NAUMANN M. , BLANKENSTEIN F. , BARTHEL C.R.
Published: January 2006

summary  For endodontically treated teeth, there are no standardized measures available to define the extent of loss in tooth substance prior to final restoration. In this study, defect size was classified and the applicability of the classification was tested related to the inter‐ and intra‐examiner reliability. For classification, three parameters were investigated: (i) remaining tooth substance in the vertical dimension (level A–D, aspect I), (ii) remaining tooth substance as regarded horizontally (mm; bucco‐lingual and mesio‐distal, aspect II), and (iii) size of the orifice (mm; aspect III). Four non‐calibrated or (pre‐trained) examiners were asked to gauge and classify 20 casts of clinically broken down teeth. The measurements were repeated twice every alternative week giving three separate readings. Inter‐examiner reliability was determined at weeks 1, 3 and 5. The intra‐examiner reliability was compared between readings 1 and 2, 1 and 3, and 2 and 3. As statistical tests, intra‐class correlation (ICC) and Cohen's kappa (weighted) were used at a significance level of P < 0·05. Inter‐ and intra‐examiner reliability for ordinal data (aspect I) revealed, with one exception, ‘moderate’ to ‘very good’ evaluations. Inter‐ and intra‐examiner reliability (ICC) of metric data of aspect II and III was primarily ‘excellent’. It may be concluded that the newly developed classification could be applied as an appropriate and reproducible method to define defect extension in endodontically treated teeth.
Epidemiological evaluation of the multifactorial aetiology of abfractions
Authors: BERNHARDT O. , GESCH D. , SCHWAHN C. , MACK F. , MEYER G. , JOHN U. , KOCHER T.
Published: January 2006

summary  The purpose of this study was to determine risk indicators for the aetiology of abfractions (cervical wedge‐shaped defects) on teeth using dental and medical variables obtained in a population‐based sample of the cross‐sectional epidemiological ‘Study of Health in Pomerania’ (SHIP). Medical history, dental, and sociodemographic parameters of 2707 representatively selected subjects 20–59 years of age with more than four natural teeth were checked for associations with the occurrence of abfractions using a two‐level logistic regression model on a tooth and a subject level. The estimated prevalence of developing abfractions generally increased with age. The following independent variables were associated with the occurrence of abfractions: buccal recession of the gingiva, odds ratio (OR) = 6·7; occlusal wear facets of scores 1, 2 and 3, OR = 1·5, 1·9, 1·9; tilted teeth, OR = 1·4; inlays, OR = 1·6; toothbrushing behaviour, OR = 1·9 to 2·0 (two and three times a day versus once a day). First premolars had the highest estimated risk for developing abfractions, followed by the second premolars. Maxillary and mandibular teeth behaved similarly in terms of abfractions, with the exception of mandibular canines, which had a much lower estimated risk of incurring abfractions than did maxillary canines. The results of this analysis indicated that abfractions are associated with occlusal factors, like occlusal wear, inlay restorations, altered tooth position and tooth brushing behaviour. This study delivers further evidence for a multifactorial aetiology of abfractions.
Genetic signatures of intermediate divergence: population history of Old and New World Holarctic ravens (Corvus corax)
Authors: OMLAND KEVIN E. , BAKER JASON M. , PETERS JEFFREY L.
Published: January 2006

Many studies of phylogeography, speciation, and species limits restrict their focus to a narrow issue: gene tree monophyly. However, reciprocal monophyly does not provide an ideal touchstone criterion of any aspect of evolutionary divergence. There is a continuum of divergence stages as isolated populations go from initial allele frequency differences to well‐differentiated species. Studying intermediate stages of divergence will increase our understanding of geographical speciation, species limits, and conservation priorities. We develop a conceptual framework and terminology for thinking about the stages of ‘intermediate polyphyly’. The Holarctic clade of common ravens (Corvus corax), found throughout much of Eurasia and North America, provides a case study of these stages of intermediate divergence. We used coalescent, phylogenetic, and population genetic methods to investigate the history and current status of this Old World–New World distribution using 107 mitochondrial control region sequences. Phylogenetically, New World and Old World samples are intermixed. However, most samples are grouped into small subclades that are restricted to either the New World or the Old World, and only one haplotype is shared between the hemispheres. Analysis of moleculalr variance (amova) results reflect this low haplotype sharing between hemispheres (ΦST = 0.13, P < 0.01). Isolation with Migration (im) coalescent results suggest a sustained period of divergence between the hemispheres and low levels of maternal gene flow. Although there has not been sufficient time to evolve reciprocal monophyly and some gene flow may occur, New World and Old World ravens are genetically quite distinct. We use this example to demonstrate these early stages of divergence as populations go from sharing only internal haplotypes, to sharing no haplotypes, to having population specific subclades. Studies of phylogeography, speciation and systematics will benefit from increased attention to these stages of intermediate polyphyly.
Specificity of the trypanothione‐dependent Leishmania major glyoxalase I: structure and biochemical comparison with the human enzyme
Authors: Ariza Antonio , Vickers Tim J. , Greig Neil , Armour Kirsten A. , Dixon Mark J. , Eggleston Ian M. , Fairlamb Alan H. , Bond Charles S.
Published: January 2006

Trypanothione replaces glutathione in defence against cellular damage caused by oxidants, xenobiotics and methylglyoxal in the trypanosomatid parasites, which cause trypanosomiasis and leishmaniasis. In Leishmania major, the first step in methylglyoxal detoxification is performed by a trypanothione‐dependent glyoxalase I (GLO1) containing a nickel cofactor; all other characterized eukaryotic glyoxalases use zinc. In kinetic studies L. major and human enzymes were active with methylglyoxal derivatives of several thiols, but showed opposite substrate selectivities: N1‐glutathionylspermidine hemithioacetal is 40‐fold better with L. major GLO1, whereas glutathione hemithioacetal is 300‐fold better with human GLO1. Similarly, S‐4‐bromobenzylglutathionylspermidine is a 24‐fold more potent linear competitive inhibitor of L. major than human GLO1 (Kis of 0.54 µM and 12.6 µM, respectively), whereas S‐4‐bromobenzylglutathione is > 4000‐fold more active against human than L. major GLO1 (Kis of 0.13 µM and > 500 µM respectively). The crystal structure of L. major GLO1 reveals differences in active site architecture to both human GLO1 and the nickel‐dependent Escherichia coli GLO1, including increased negative charge and hydrophobic character and truncation of a loop that may regulate catalysis in the human enzyme. These differences correlate with the differential binding of glutathione and trypanothione‐based substrates, and thus offer a route to the rational design of L. major‐specific GLO1 inhibitors.
Mechanism of polarization of Listeria monocytogenes surface protein ActA
Authors: Rafelski Susanne M. , Theriot Julie A.
Published: January 2006

The polar distribution of the ActA protein on the surface of the Gram‐positive intracellular bacterial pathogen, Listeria monocytogenes, is required for bacterial actin‐based motility and successful infection. ActA spans both the bacterial membrane and the peptidoglycan cell wall. We have directly examined the de novo ActA polarization process in vitro by using an ActA–RFP (red fluorescent protein) fusion. After induction of expression, ActA initially appeared at distinct sites along the sides of bacteria and was then redistributed over the entire cylindrical cell body through helical cell wall growth. The accumulation of ActA at the bacterial poles displayed slower kinetics, occurring over several bacterial generations. ActA accumulated more efficiently at younger, less inert poles, and proper polarization required an optimal balance between protein secretion and bacterial growth rates. Within infected host cells, younger generations of L. monocytogenes initiated motility more quickly than older ones, consistent with our in vitro observations of de novo ActA polarization. We propose a model in which the polarization of ActA, and possibly other Gram‐positive cell wall‐associated proteins, may be a direct consequence of the differential cell wall growth rates along the bacterium and dependent on the relative rates of protein secretion, protein degradation and bacterial growth.
The chromosomal relBE2 toxin–antitoxin locus of Streptococcus pneumoniae: characterization and use of a bioluminescence resonance energy transfer assay to detect toxin–antitoxin interaction
Authors: Nieto Concha , Pellicer Teresa , Balsa Dolors , Christensen Suzanne K. , Gerdes Kenn , Espinosa Manuel
Published: January 2006

Proteic toxin–antitoxin (TA) loci were first identified in bacterial plasmids, and they were regarded as involved in stable plasmid maintenance by a so‐called ‘addiction’ mechanism. Later, chromosomally encoded TA loci were identified and their function ascribed to survival mechanisms when bacteria were subjected to stress. In the search for chromosomally encoded TA loci in Gram‐positive bacteria, we identified various in the pathogen Streptococcus pneumoniae. Two of these cassettes, sharing homology with the Escherichia coli relBE locus were cloned and tested for their activity. The relBE2Spn locus resulted to be a bona fide TA locus. The toxin exhibited high toxicity towards E. coli and S. pneumoniae, although in the latter, the chromosomal copy of the antitoxin relB2Spn gene had to be inactivated to detect full toxicity. Cell growth arrest caused by expression of the relE2Spn toxin gene could be reverted by expression of the cognate antitoxin, relB2Spn, although prolonged exposition to the toxin led to cell death. The pneumococcal relBE2Spn locus is the first instance of a chromosomally encoded TA system from Gram‐positive bacteria characterized in its own host. We have developed a bioluminescence resonance energy transfer (BRET) assay to detect the interactions between the RelB2Spn antitoxin and the RelE2Spn toxin in vivo. This technique has shown to be amenable to a high‐throughput screening (HTS), opening new avenues in the search of molecules with potential antibacterial activity able to inhibit TA interactions.
Sedimentary response to a tectonically induced sea‐level fall in a shallow back‐arc basin: the Mulichinco Formation (Lower Cretaceous), Neuquén Basin, Argentina
Authors: SCHWARZ ERNESTO , SPALLETTI LUIS A. , HOWELL JOHN A.
Published: January 2006

This study examines the sedimentary response to a tectonically driven relative sea‐level fall that occurred in the Neuquén Basin, west‐central Argentina, during the late Early Valanginian (Early Cretaceous). At this time the basin lay behind the emergent Andean magmatic arc to the west. Following the relative sea‐level fall, sedimentation was limited to the central part of the Neuquén Basin, with the deposition of a predominantly clastic, continental to shallow marine wedge on top of basinal black shales. This lowstand wedge is called the Mulichinco Formation and consists of a third‐order sequence that lasted about 2 Myr and contains high frequency lowstand, transgressive, and highstand deposits. Significant variations in facies, depositional architecture, and internal organization of the sequence occur along depositional strike. These variations are attributed mainly to tectonic and topographic controls upon sediment flux, basin gradient, fault tilting, and shifting of the depocentre through time. These controls were ultimately related to asymmetrically distributed tectonic activity that was greater towards the magmatic arc in the west. The superposition of fluvial deposits directly upon offshore facies provides unequivocal evidence for a sequence boundary at the base of the Mulichinco Formation. However, the Mulichinco sequence boundary is marked by shallow, low erosional relief and widespread fluvial deposition. The surface lacks prominent valleys traditionally associated with sequence boundaries. This non‐erosive sequence boundary geometry is attributed to the ramp‐type geometry of the basin and/or rapid uplift that limited stratigraphic adjustment to base‐level fall. Significant along‐strike facies changes and a low‐relief sequence boundary are attributes that may be common in tectonically active, semi‐enclosed basins (e.g. shallow back‐arc basins, foreland basins).
An investigation of subglacial processes at the microscale from Briksdalsbreen, Norway
Authors: HART JANE K.
Published: January 2006

The subglacial processes at Briksdalsbreen, Norway, are examined by a combination of sedimentology, thin section and scanning electron microscope (SEM) analysis of till samples from an exposed subglacial surface and from beneath the glacier. Studies of a fluted surface indicate that subglacial deformation is occurring on a field scale with flutes forming behind most clasts 0·6 m high. At the thin section scale (0·014–2·0 mm) it is seen that deformation is by rotation and attenuation and is dependent on till texture. At the SEM scale (0·1–0·4 mm) it is seen that erosion is controlled by abrasion and percussion which produces distinct grain ‘styles’ as part of an erosional continuum. Overall it is shown that rotation and attenuation is a dominant process at all scales and that the clast interactions associated with different scale perturbations within the shear zone control erosion and deposition, as well as landform and fabric production.
Oligocene to Present kilometres scale subsidence and exhumation of the Ligurian Alps and the Tertiary Piedmont Basin (NW Italy) revealed by apatite (U–Th)/He thermochronology: correlation with regional tectonics
Authors: Bertotti Giovanni , Mosca Pietro , Juez Joaquim , Polino Riccardo , Dunai Tibor
Published: January 2006

The Ligurian Alps segment of the Alpine–Apennine orogen in NW Italy is unconformably covered by Upper Eocene to Holocene sediments in the Tertiary Piedmont Basin (TPB) and Po Plain. These sediments dip towards the north demonstrating the erosional nature of the southern border of the succession and implying that the adjacent orogenic belt formed the substratum rather than the margin of the sedimentary basin. Apatite (U–Th)/He and fission track thermochronology shows that the orogen first subsided and was buried at >4 km from 30 to 26 Ma and began its exhumation thereafter. From 26 Ma to present, this upward movement was contemporaneous with subsidence in the northern TPB. The couple exhumation in the S and subsidence in the N migrated northwards through time. Vertical movements in the area are similar to those reconstructed in Corsica. In both cases, the onset of exhumation becomes younger away from the Ligurian‐Provençal basin and has little correlation with the opening of the surrounding oceanic basins.
Gravitational spreading and formation of new rift zones on overlapping volcanoes
Authors: Walter Thomas R. , Klügel Andreas , Münn Sebastian
Published: January 2006

Large volcanic edifices are often shaped by the coalescence of adjacent volcanoes as well as intrusive rift zones and gravitational spreading. To better understand the structure of such volcanoes we designed analogue experiments simulating gravitational spreading of an edifice made by overlapping cones of different age, and examined the formation of rift zones. The results allow distinction of two main rift geometries. (i) Spreading edifices of similar age that partly overlap, tend to develop a rift zone approximately perpendicular to the boundary of both volcanoes. Such a rift zone causes two volcanoes to grow together and form an elongated topographic ridge. (ii) Partly overlapping volcanoes of different age are spreading at different rates and thus form a rift zone parallel to the boundary of both volcanoes. Such a rift zone causes two volcanoes to structurally separate. The results are widely applicable for large volcanoes subject to rifting and flank spreading, which we demonstrate for Réunion Island and for southern Hawaii.
Two unknown M > 6 historical earthquakes revealed by palaeoseismological and archival researches in eastern Calabria (southern Italy). Seismotectonic implications
Authors: Galli P. , Scionti V.
Published: January 2006

The seismicity of Calabria is among the strongest in the whole of the Mediterranean, but is now well known on its Ionian side. Palaeoseismological investigations in eastern Calabria and archival research have tried to shed light on earthquake recurrence and seismogenetic source geometry. Trench investigation across the Lakes fault (Sila massif) shows this fault to be definitively responsible for the Mw = 6.7, 1638 earthquake, and provides a well‐constrained age range for its penultimate event (early 7th century AD). On the other hand, after research in local and national archives, another previously unknown relevant historical earthquake has been discovered (1744, Mw = 6.2), which struck an area conterminous to the SE tip of the Lakes fault. We hypothesize a NW–SE active Sila fault system that accommodates regional ∼N–S extension through normal‐to‐sinistral segments, each one capable of generating earthquakes with magnitude in the range of 6.2–6.7. Since 1638, this system ruptured almost entirely from NW towards SE (1638–1744–1832), with the exception of the northwestern segment, the ‘silent’ Cecita fault.
A Seminoma in a Monorchid Guinea Fowl (Numida meleagris)
Authors: Kurkure N. V. , Pande V. V. , Thomas F. , Bhandarkar A. G.
Published: January 2006

A case of seminoma in a monorchid adult guinea fowl (Numida meleagris) is described. Grossly, a right enlarged testis, which was soft in consistency, and white to pale in colour with few spots of haemorrhages was observed. Histologically, the testicle revealed diffusely spread sheets of tumour cells. The cells were large pleomorphic with eccentrically placed hyperchromic nuclei. Mitotic figures were evident. A scanty fibrous stroma, containing lymphocytes and histiocytes, separating the groups of tumour cells, along with few areas of haemorrhages were observed. Occurrence of seminoma in guinea fowl is unusual and hence reported.