bluuebunny/crossref_metadata_2025 huggingface dataset:
Formulas for determining the dimensions of venous graft required for penile curvature correction
Authors: Hsu G.‐L. , Hsieh C.‐H. , Wen H.‐S. , Ling P.‐Y. , Chen S.‐Y. , Huang H.‐M. , Tseng G.‐F.
Published: March 2006

To evaluate the quantity of penile veins for use as patch material for the treatment of penile curvature, we devised two formulas: from the calculus of applied civil engineering and a diagram from the goniometry of the cadavers’ penises, respectively, and the techniques for their application. From March 1995 to July 2003, a total of 65 consecutive patients with penile curvature – 41 men with Peyronie's deformity and 24 with congenital penile deviations – underwent grafting with autologous deep dorsal veins with or without cavernosal veins as patch material. The patched veins required were calculated from the formula πr2θ/45°, which is derived from calculus. The tunical incision sector was meticulously performed in accordance with our diagram which is interpolated from seven male cadavers via goniometry and consequently the length of patched veins required was 2πrθ′/θ. The corporotomy defect was fashioned with the detubularized veins after they were adequately prepared and spliced. In these patients, the average available area of the veins was 4.9 × 2.2 cm2 (range, 4.5 × 1.8 to 5.6 × 2.4), which seemed adequate in all cases for patching, although 11 of them required two patches. Overall, 21 patients required a modified Nesbit's procedure on the contralateral/ipsilateral tunica to attain a satisfactory penile shape. Because of its anatomical vicinity and its availability as material, the deep dorsal vein associated with the cavernosal vein may play an indispensable role in grafting even with local anaesthesia on an outpatient basis.
Can lycopene be delivered into semen via prostasomes? In vitro incorporation and retention studies
Authors: Goyal A. , Delves G. H. , Chopra M. , Lwaleed B. A. , Cooper A. J.
Published: March 2006

Lycopene (C40 H56) is a highly lipophilic antioxidant found in human semen in nanomolar concentrations. It has been shown to be one of the most potent carotenoid antioxidant in various human studies. Prostasomes are organelles secreted by glandular prostatic epithelial cells and are known to play an important role in fertility and prostate cancer. They are also known to possess antioxidant activity and aid the functioning of sperm. We studied the ability of these vesicles to adsorb and retain lycopene into their rich lipid environment in vitro. High‐performance liquid chromatography analysis confirmed micrograms of lycopene per milligram of prostasomal protein. In view of the prostasomes’ lipid‐rich nature it is highly likely that these organelles act as delivery vehicles for this highly lipophilic antioxidant substance into human semen.
How to get one's voice heard: the problems of the discharge planning conference
Authors: Efraimsson Eva , Sandman Per‐Olof , Hydén Lars‐Christer , Holritz Rasmussen Birgit
Published: March 2006

Aims.  This paper reports a study describing how patients, relatives and healthcare professionals dealt with the variety of problems and responsibilities that occur in discharge planning conferences and especially how they managed to do this given the institutional frame that surrounded the meeting.

Background.  In Sweden, the aim of a discharge planning conference is to co‐ordinate social and healthcare resources as patients are discharged from hospitals. Patients, relatives and hospital staff, along with healthcare professionals responsible for outpatient care, assemble to achieve an individual care plan. One of the explicit principles informing the discharge planning conference is to increase patients’ influence on decision‐making. However, research points at shortcomings in this respect.

Method.  A discourse analysis was conducted using transcriptions of eight video‐recorded discharge planning conferences. The selected patients were eight older women expected to be discharged from hospital. Other participants were staff nurses, social workers and occasionally relatives, an occupational therapist, district nurse or home care aide.

Findings.  Participants adopted different roles as persons/patients, relative/next of kin and healthcare professionals/institutional representatives during the discharge planning conference, which they simultaneously struggled to act upon. The findings are presented under the categories ‘Clashing roles and perspectives’ and ‘Facing the institutional frame’.

Conclusions.  The performance of the discharge planning conference in its present form interferes with a caring perspective that protects patients’ integrity and gives prominence to their life worlds. Moreover, it does not satisfy patients’ and relatives’ right to expect proceedings that enhance their possibility to express their personal wishes in a dignified manner.
A theory for the nursing care of patients at risk of suicide
Authors: Sun Fan‐Ko , Long Ann , Boore Jennifer , Tsao Lee‐Ing
Published: March 2006

Aim.  This paper presents a nursing care theory developed to guide the care given to people with suicidal ideas and those with a previous suicide attempt.

Background.  Suicide is a major public health problem. According to the World Health Organization, international suicide rates range from highs of more than 20 per 100 000 people in Hungary (1997 figures), to fewer than 10 per 100 000 in the United Kingdom (2002 figures). In 2002, the number of completed suicides in Taiwan increased by nearly 10% over the previous year, and the Taiwanese Government has set targets to reduce this rate. Psychiatric nurses play a vital role in helping reduce the suicide rate through prevention, education and by providing care that promotes the healing of patients who attempt suicide.

Methods.  A grounded theory approach was used. Fifteen patients who had either suicidal ideas or had attempted suicide and 15 psychiatric nurses working on acute wards were interviewed and observed using an observer‐as‐participant strategy. Data were collected through field notes and by tape‐recorded interviews during 2003, and analysed using open, axial and selective coding and the qualitative software program QRS NUD*IST.

Findings.  The core category that emerged from the data collected was the provision of ‘safe and compassionate care via the channel of the therapeutic relationship’. Other key categories linked to and embraced within this core category were: providing holistic assessments; providing protection; providing basic care; and promoting healing through advanced care.

Conclusion.  The theory generated from the findings could be used by nurses as a guide as they initiate and maintain therapeutic relationships with patients who are at risk of suicide. The theory could advance the quality of care provided by nurses. In addition, it holds potential for instilling hope in patients who have lost their ability to cope with life events and perhaps life itself.
Promotion of evidence‐based practice by professional nursing associations: literature review
Authors: Holleman Gerda , Eliens Aart , Van Vliet Marjolein , Van Achterberg Theo
Published: March 2006

Aim.  This paper reports a literature review examining the activities of professional nursing associations in the promotion of evidence‐based practice.

Background.  Professional nursing associations can play a role in the implementation and achievement of evidence‐based practice as such associations aim to develop and further educate nurses professionally, build professional networks representing the interests of nurses and the nursing profession, influence the government and policymakers, and support and protect the basic values of nurses. The exact role of professional nursing associations in the promotion of evidence‐based practice is as yet unclear, along with just how the role of such associations can be expanded and which strategies can be used to promote evidence‐based practice among members.

Method.  A literature and Internet search was undertaken using the PUBMED, CINAHL, SCIRUS, INVERT, and the Cochrane databases using the terms evidence‐based practice(s)* or EBP*, which were then combined with Nursing Society*, Nursing Organization*, Nursing Organisation*, Nursing Association* or Nursing Council*. Other sources included a Google search of the Internet, and the sites of various members of the International Council of Nurses. Publications in English, French or German from 1993 to 2004 were used, and the Internet search was conducted on 17 July 2003.

Results.  Sixty nursing associations described the dissemination of evidence‐based practice using one or more types of activities (179 activities in total). All of these activities were of a voluntary nature, with a predominant focus (132/179 activities) on intrinsic motivation of nurses. More specifically, most of the activities were aimed at nurses’ competences and attitudes in relation to evidence‐based practice.

Conclusion.  Professional nurses’ associations are active in promoting evidence‐based practice among their nurse members, but only those focusing on changing competences and attitude by addressing intrinsic motivation are well used. Other types of activities deserve to be explored, including behaviour‐oriented approaches, approaches using structural, social or financial influence measures and perhaps methods based on ‘involuntary involvement’.
Effectiveness of an HIV/AIDS educational programme for Chinese nurses
Authors: Williams Ann B. , Wang Honghong , Burgess Jane , Wu Chenghui , Gong Yuxiu , Li Yao
Published: March 2006

Aim. This paper reports a study examining the effect of a multifaceted HIV/AIDS educational intervention on the knowledge, attitudes and willingness of Chinese nurses in caring for patients with human immunodeficiency virus.

Background. The expanding HIV/AIDS epidemic challenges nurses to increase their knowledge about this devastating illness to provide effective HIV/AIDS prevention and care to their patients. HIV/AIDS educational interventions, which were developed for North American and European nurses, have not been studied among nurses in other societies.

Methods. The study employed a pretest, post‐test experimental design with 208 nurses from seven Chinese provinces. The intervention consisted of a 5‐day workshop comprising didactic lectures interspersed with activities designed to elicit discussion of participants’ values and personal feelings about HIV/AIDS. Bloom's Taxonomy and principles of good HIV/AIDS educational practice guided the educational intervention. Outcome variables were HIV/AIDS knowledge, attitude toward patients with HIV/AIDS (including empathy for and desire to avoid these patients) and willingness to provide nursing care to these patients. The data were collected in 2003.

Findings. At baseline, HIV/AIDS knowledge was not high and attitudes and willingness to care were neutral. Knowledge, attitudes toward patients with HIV/AIDS and willingness to provide nursing care to these patients were each improved at the conclusion of the workshop (P < 0·001).

Conclusions. As the HIV/AIDS epidemic expands, nurses will be called upon to deliver competent, compassionate and comprehensive care to patients and their significant others. Intensive, interactive HIV/AIDS professional workshops can contribute to the national effort by increasing knowledge and improving attitudes towards and willingness to provide nursing care for patients with HIV/AIDS.
Competence of newly‐graduated nurses – a comparison of the perceptions of qualified nurses and students
Authors: Lofmark Anna , Smide Bibbi , Wikblad Karin
Published: March 2006

Aim.  This paper reports a study that compares opinions of final year nursing students, rating their own competence, with the opinions of experienced nurses on the competence of newly‐graduated nurses.

Background.  The transition of nursing preparation into higher education is regarded as positive, although it has led to differences in opinion about the competence of newly‐graduated nurses and their readiness to enter the nursing profession. There are studies showing that newly‐graduated nurses perceive themselves as holistically focused, professional practitioners, while other nurses are concerned that newly‐graduated nurses do not have necessary skills.

Methods.  A convenience sample of 106 nursing students in the final week of their course and 136 nurses who had experience of supervising nursing students completed a questionnaire. The data were collected in 2002.

Results.  Own competence, in the form of ability to perform nursing care, was rated by nursing students to be good or strongly developed in most of the investigated areas of nursing care. Experienced nurses also estimated newly‐graduated nurses’ competence to be good or strongly developed, although to a lesser extent. Nurses qualified within the previous 5 years rated newly‐graduated nurses’ competence to be higher in comparison with those with less recent education.

Conclusions.  Further studies are needed to broaden our understanding of why some areas of nursing care, such as ethical awareness, were rated very highly, while others, like informing and teaching of co‐workers and planning and prioritizing interventions had the lowest rating.
Autogenic training to reduce anxiety in nursing students: randomized controlled trial
Authors: Kanji Nasim , White Adrian , Ernst Edzard
Published: March 2006

Aim.  This paper reports a study to determine the effectiveness of autogenic training in reducing anxiety in nursing students.

Background.  Nursing is stressful, and nursing students also have the additional pressures and uncertainties shared with all academic students. Autogenic training is a relaxation technique consisting of six mental exercises and is aimed at relieving tension, anger and stress. Meta‐analysis has found large effect sizes for autogenic trainings intervention comparisons, medium effect sizes against control groups, and no effects when compared with other psychological therapies. A controlled trial with 50 nursing students found that the number of certified days off sick was reduced by autogenic training compared with no treatment, and a second trial with only 18 students reported greater improvement in Trait Anxiety, but not State Anxiety, compared with untreated controls.

Methods.  A randomized controlled trial with three parallel arms was completed in 1998 with 93 nursing students aged 19–49 years. The setting was a university college in the United Kingdom. The treatment group received eight weekly sessions of autogenic training, the attention control group received eight weekly sessions of laughter therapy, and the time control group received no intervention. The outcome measures were the State‐Trait Anxiety Inventory, the Maslach Burnout Inventory, blood pressure and pulse rate completed at baseline, 2 months (end of treatment), and 5, 8, and 11 months from randomization.

Results.  There was a statistically significantly greater reduction of State (P < 0·001) and Trait (P < 0·001) Anxiety in the autogenic training group than in both other groups immediately after treatment. There were no differences between the groups for the Maslach Burnout Inventory. The autogenic training group also showed statistically significantly greater reduction immediately after treatment in systolic (P < 0·01) and diastolic (P < 0·05) blood pressure, and pulse rate (P < 0·002), than the other two groups.

Conclusion.  Autogenic training has at least a short‐term effect in alleviating stress in nursing students.
Influence of mowing on the persistence of two endangered large blue butterfly species
Authors: JOHST KARIN , DRECHSLER MARTIN , THOMAS JEREMY , SETTELE JOSEF
Published: March 2006

Mowing influences two endangered butterfly species, Maculinea nausithous and Maculinea teleius, directly through egg destruction and larval mortality on the mown plants and indirectly through altering the abundance of their sequential resources in meadows (Sanguisorba plants for oviposition and early larval development and Myrmica ant nests for later larval development and pupation). Although conservation biologists have argued that mowing during the adult stage is detrimental to population persistence, it is not obvious how the timing and frequency of mowing impact on population dynamics.

A simulation model was used to investigate how current ‘traditional’ mowing regimes could be altered to reconcile butterfly conservation with agriculture.

The key mechanism affecting the impact of mowing on population persistence was the interaction between density‐independent and density‐dependent mortalities in different larval stages of each life cycle. Because of this interaction, optimal mowing regimes for butterfly conservation were sensitive to the type of density regulation displayed by each species, and to landscape attributes such as the influence of climate on resource availability and the level of parasitism. Despite this sensitivity, we were able to identify robust mowing regimes appropriate for a wide range of landscape attributes and to derive general management recommendations.

Synthesis and applications. Our results showed that the ‘traditional’ mowing regime (twice per year with the second cut during the flight period) was always detrimental to the two butterfly species at both local (single population) and regional (metapopulation) scales. However, mowing once a year, or every second or third year, before or after the flight period, was appropriate for both species in the considered landscapes. Maculinea teleius could persist only at a regional scale, assuming dispersal among the meadows, whereas M. nausithous could persist at both local and regional scales. Thus it is essential that the recommended mowing regimes are applied across several connected meadows within reach of dispersing butterflies if both butterflies are to be conserved in a region.
Polyphagy complicates conservation biological control that targets generalist predators
Authors: PRASAD R. P. , SNYDER W. E.
Published: March 2006

While evidence suggests that undisturbed refuges within agricultural fields conserve natural enemies, few studies have examined whether pest control does actually improve following predator conservation. When the targets of conservation are generalists, polyphagy may complicate the impact of the conserved predators on agricultural pests.

We examined the use of beetle banks to conserve predatory beetles for the control of pest Diptera. Locally, the community of predatory beetles included several species of small carabid and staphylinid beetles (< 1 cm in length), which eat fly eggs, and one common larger carabid beetle (> 1·5 cm),Pterostichus melanarius, which rarely eats fly eggs but does eat smaller beetles.

Predator beetle activity densities, but not rates of fly egg predation, increased in fields including beetle banks. A series of field experiments was conducted to examine whether two types of polyphagy, intraguild predation and feeding on non‐target prey, could be preventing increased egg predation following successful predator conservation.

The putative intraguild predatorPterostichus melanariusreduced activity densities of smaller beetles, and thus weakened fly egg predation. The strength of fly suppression increased with increasing densities of small beetles in the absence ofPterostichus melanarius, but not when aphid alternative prey were readily available. In the presence of abundant aphids, egg predation rates did not increase at higher small beetle densities.

Synthesis and applications.Overall, our results suggest that both intraguild predation and the presence of alternative prey could limit conservation biological control that targets generalist predators. Thus, higher predator densities will not necessarily lead to improved pest control. Ecologists must consider the impact of predator manipulations at multiple trophic levels when assessing the success or failure of conservation biological control.
Habitat heterogeneity influences connectivity in a spatially structured pest population
Authors: HAMILTON G. S. , MATHER P. B. , WILSON J C.
Published: March 2006

Patterns of connectivity influence pest population system dynamics, and it is essential to consider connectivity when planning effective management strategies. Traditional connectivity models often consider populations embedded in a matrix of unsuitable habitat. This approach is unlikely to be applicable to those pest species that can utilize most of the landscape in which they live. There is therefore a need for a simple and flexible tool to assess connectivity in such systems.

In this study, we developed a new model in which contiguous resource patches that differ in quality, and landscape elements that impede dispersal, impact on connectivity within a population system. The model was applied to a wild rabbit population system, a well‐studied pest species in Australia. An independent population genetic data set was used to validate the model.

There was a highly significant association between pairwise population connectivity and the genetic data (Mantel test,r=−0·502,P= 0·002). As predicted, two populations that showed very low connectivity were strongly isolated genetically. These sites appeared to be substantially isolated because of forests, which acted to impede rabbit dispersal. When these sites were excluded from analysis, connectivity indices again explained the pattern of genetic data (Mantel test,r=−0·46,P= 0·037). This showed that both spatial variation in resource quality and forests influenced connectivity in this system. Sensitivity analyses confirmed that the distribution and extent of forests was important in limiting connectivity to some sites. The model was relatively robust to changes in population parameters.

Synthesis and applications. Connectivity among wild rabbit populations in this system was strongly influenced by habitat heterogeneity, rather than factors such as geographical distance or major landscape elements such as rivers, both of which are traditionally considered to influence system dynamics. This may have substantial implications for many pest systems, and suggests that the impact of habitat heterogeneity on connectivity should be considered when planning efficient management strategies.
The impact of HBV‐DNA fluctuations on virus‐specific CD8+ T cells in HBeAg+ chronic hepatitis B patients treated with a steroid and lamivudine
Authors: Gotto J. , Webster G. J. M. , Brown D. , Jenkins J. , Dusheiko G. M. , Bertoletti A.
Published: March 2006

Summary.  Restoration of anti‐viral immune response may be a requisite for sustained virological response to treatment in chronic hepatitis B patients. Over a 13‐month period, we examined the dynamics of hepatitis B virus (HBV)‐specific CD8+ cells in six human leucocyte antigen (HLA)‐A2+ hepatitis B e antigen (HBeAg)+ ‘immunotolerant’ chronic hepatitis B patients treated sequentially with corticosteroid and lamivudine. Our results show that the combination treatment did not result in a sustained restoration of anti‐viral specific CD8+ cells in five of the six patients studied. However, HBV‐specific CD8+ cells, despite being severely compromised, were not totally deleted. Paradoxically, steroid treatment was not associated with inhibition but with a minimal increase of the HBV‐specific CD8 response, and we observed that nucleocapsid‐specific CD8 responses were not rescued by stable and prolonged inhibition but became detectable after rapid rebounds of HBV replication. In most patients, the transient and minimal restoration of HBV‐specific immunity was not associated with clinical benefits. Our results describe a dynamic relationship between HBV‐specific CD8+ cells and HBV‐DNA values, that could potentially be used for a better design of HBV treatment in HBeAg+ ‘immunotolerant’ chronic hepatitis B patients.
Effects of bezafibrate in patients with chronic hepatitis C virus infection: combination with interferon and ribavirin
Authors: Fujita N. , Kaito M. , Kai M. , Sugimoto R. , Tanaka H. , Horiike S. , Konishi M. , Iwasa M. , Watanabe S. , Adachi Y.
Published: March 2006

Summary.  An association of hepatitis C virus (HCV) with low‐density lipoproteins (LDL) in serum of patients with chronic hepatitis C (CHC) has been suggested. We conducted a prospective study in CHC patients complicated with hyperlipidaemia, to examine whether bezafibrate, which is commonly used for treatment of hyperlipidaemia, reduces serum HCV‐RNA titre and improves liver dysfunction. Fifteen patients received daily oral bezafibrate treatment (400 mg/day) for 8 weeks, and its effects on serum lipids, transaminases, HCV‐RNA titres, and HCV‐RNA titres bound to LDL were evaluated. Fifteen untreated patients with CHC and hyperlipidaemia were used as controls. The mean serum alanine aminotransferase levels and HCV‐RNA titres significantly decreased at the end of bezafibrate therapy in the treated group (105 ± 34 to 80 ± 32 IU/L, P = 0.02 and 2.23 ± 2.71 to 1.78 ± 2.38 × 107 copies/mL, P < 0.01 respectively), but no changes were observed in the control group. Serum HCV‐RNA titres bound to LDL, as quantified by immunoprecipitation using anti‐LDL antibody, also decreased in all 15 treated patients [5.55 ± 6.59 to 1.07 ± 1.58 × 106 copies/ml, P < 0.01 (mean reduction rate was −78.5 ± 17.0%)]. Sucrose density‐gradient ultracentrifugation study revealed that HCV‐RNA‐decreased density fractions after the bezafibrate were identical to LDL‐density fractions (1.015–1.062 g/mL). Eight CHC patients were treated with bezafibrate, interferon, and ribavirin triple therapy for 32 weeks, and four patients achieved sustained virological response to therapy. This pilot study provides further evidence of an association between HCV and LDL in serum and suggests the potential usefulness of bezafibrate as an anti‐HCV reagent for the treatment of CHC patients.
Lifestyle changes and beliefs regarding disease severity in patients with chronic hepatitis C
Authors: Castera L. , Constant A. , Bernard P‐H. , De Ledinghen V. , Couzigou P.
Published: March 2006

Summary. The aim of this prospective study was to investigate beliefs regarding disease severity and lifestyle changes following hepatitis C diagnosis in patients with chronic hepatitis C (CHC). One hundred and eighty‐five consecutive CHC patients were interviewed by means of self‐questionnaires exploring several aspects of their disease. Most patients (93%) identified cirrhosis and liver cancer as the two main complications of CHC. More than half of patients (59%) thought that CHC was always associated with a fatal outcome whereas 3% thought that they would stay healthy. HCV viral load was the most commonly reported factor associated with disease severity. Sex life changes were reported by 107 patients (58%) whereas dietary intake changes were reported by 88 patients (48%). In multivariate analysis, changes in sex life were associated with male gender [odds ratio (OR): 2.57, 95% CI: 1.30–5.08,P < 0.007], perceived disease severity (OR: 1.02, 95% CI: 1.00–1.03,P < 0.03) and anxiety (OR: 1.05, 95% CI: 1.01–1.08,P < 0.003), whereas changes in dietary intake were associated with age (OR: 1.04, 95% CI: 1.02–1.08,P < 0.003) and anxiety (OR: 1.04, 95% CI: 1.01–1.08,P < 0.006). Our results show the considerable impact of CHC diagnosis on patients’ lifestyle. They emphasize the need for improving CHC patient counselling in order to avoid unnecessary sex life and dietary intake changes.
The determinant role of temporary proglacial drainages on the genetic structure of fishes
Authors: GAGNON M.‐C. , ANGERS B.
Published: March 2006

Phylogeographic studies have shed light on Pleistocene glaciations as a key factor in shaping present‐day genetic structure of many organisms. In formerly glaciated regions, the combined action of several factors such as refuges origin, physiological capacities and demographic parameters have contributed importantly to this process but specifically for each species. Therefore, a fine‐scale genetic structure is not expected to be similar for different species, unless it has been modulated by the action of a strong environmental pressure. The aim of this study is to investigate the effects of postglacial environment on the genetic structure of fishes. To achieve this objective, three fish species (northern pike, lake whitefish and yellow perch) commonly found in sympatry in Laurentian Shield lakes but displaying different ecological and physiological characteristics were analysed. The comparison of these unrelated species was performed to identify the factors determining the organization of their genetic structure. Populations of all species mostly originated from the Mississippian refuge. Low genetic differentiation was observed among populations but significant structures were detected for the three species. Despite marked differences among species, these structures presented common characteristics: a lack of congruence with drainage and a longitudinal organization. This suggested that the dispersion of species occurred independently, leading to a species‐specific structure. However, the settling of populations appeared to be mediated by a dynamic system of proglacial meltwater streams associated to the glacial Lake Ojibway‐Barlow, providing such similarities among species.
Patterns, sources and ecological implications of clonal diversity in apomictic Ranunculus carpaticola (Ranunculus auricomus complex, Ranunculaceae)
Authors: PAUN O. , GREILHUBER J. , TEMSCH E. M. , HÖRANDL E.
Published: March 2006

Sources and implications of genetic diversity in agamic complexes are still under debate. Population studies (amplified fragment length polymorphisms, microsatellites) and karyological methods (Feulgen DNA image densitometry and flow cytometry) were employed for characterization of genetic diversity and ploidy levels of 10 populations of Ranunculus carpaticola in central Slovakia. Whereas two diploid populations showed high levels of genetic diversity, as expected for sexual reproduction, eight populations are hexaploid and harbour lower degrees of genotypic variation, but maintain high levels of heterozygosity at many loci, as is typical for apomicts. Polyploid populations consist either of a single AFLP genotype or of one dominant and a few deviating genotypes. genotype/genodive and character incompatibility analyses suggest that genotypic variation within apomictic populations is caused by mutations, but in one population probably also by recombination. This local facultative sexuality may have a great impact on regional genotypic diversity. Two microsatellite loci discriminated genotypes separated by the accumulation of few mutations (‘clone mates’) within each AFLP clone. Genetic diversity is partitioned mainly among apomictic populations and is not geographically structured, which may be due to facultative sexuality and/or multiple colonizations of sites by different clones. Habitat differentiation and a tendency to inhabit artificial meadows is more pronounced in apomictic than in sexual populations. We hypothesize that maintenance of genetic diversity and superior colonizing abilities of apomicts in temporally and spatially heterogeneous environments are important for their distributional success.
Mitochondrial evidence for distinct phylogeographic units in the endangered Malagasy poison frogMantella bernhardi
Authors: VIEITES DAVID R. , CHIARI YLENIA , VENCES MIGUEL , ANDREONE FRANCO , RABEMANANJARA FALITIANA , BORA PARFAIT , NIETO‐ROMÁN SANDRA , MEYER AXEL
Published: March 2006

Mantella bernhardiis an endemic species of Malagasy poison frog threatened by loss and fragmentation of its natural habitat and collection for the pet trade. It is classified as threatened according to the International Union for Conservation of Nature and Natural Resources (IUCN) categories and included in Appendix II of the Convention on the International Trade of Endangered Species (CITES). A recent survey has increased the known distributional range of the species from one to eight populations across southeastern Madagascar, but little is known about its biology and genetic diversity. Here we estimate inter‐ and intrapopulation mitochondrial genetic variation of four populations. Populations from the northern and southern parts of the distributional range showed a high degree of divergence (maximum of 11.35% in cytochromeb) and were recovered as reciprocally monophyletic groups. Nine haplotypes were detected in the northern and 12 in the southern populations. The population from Ranomafana National Park showed the lowest number of haplotypes and nucleotide diversity, and shared its most common haplotype with the second northern population from Tolongoina. All the other detected haplotypes were unique to each of the four populations. This suggests the existence of important barriers to gene flow, pre‐dating human colonization of Madagascar at about 2000 years ago, in distinct contrast to otherMantellaspecies that show a high degree of haplotype sharing throughout their range. The continued habitat fragmentation within the distribution range ofM. bernhardiprevents any connection between its populations. Our data indicate the existence of at least two different management units for conservation in this species, corresponding to the North and South of its distribution range, and highlight the existence of strong regional endemism in southeastern Madagascar.
Genetic diversity, population structure, effective population size and demographic history of the Finnish wolf population
Authors: ASPI J. , ROININEN E. , RUOKONEN M. , KOJOLA I. , VILÀ C.
Published: March 2006

The Finnish wolf population (Canis lupus) was sampled during three different periods (1996–1998, 1999–2001 and 2002–2004), and 118 individuals were genotyped with 10 microsatellite markers. Large genetic variation was found in the population despite a recent demographic bottleneck. No spatial population subdivision was found even though a significant negative relationship between genetic relatedness and geographic distance suggested isolation by distance. Very few individuals did not belong to the local wolf population as determined by assignment analyses, suggesting a low level of immigration in the population. We used the temporal approach and several statistical methods to estimate the variance effective size of the population. All methods gave similar estimates of effective population size, approximately 40 wolves. These estimates were slightly larger than the estimated census size of breeding individuals. A Bayesian model based on Markov chain Monte Carlo simulations indicated strong evidence for a long‐term population decline. These results suggest that the contemporary wolf population size is roughly 8% of its historical size, and that the population decline dates back to late 19th century or early 20th century. Despite an increase of over 50% in the census size of the population during the whole study period, there was only weak evidence that the effective population size during the last period was higher than during the first. This may be caused by increased inbreeding, diminished dispersal within the population, and decreased immigration to the population during the last study period.
Coactivation of Vibrio vulnificus putAP operon by cAMP receptor protein and PutR through cooperative binding to overlapping sites
Authors: Lee Jeong Hyun , Choi Sang Ho
Published: March 2006

The cAMP receptor protein (CRP) positively regulates the expression of Vibrio vulnificus putAP genes encoding a proline dehydrogenase and a proline permease. In the present study, an open reading frame encoding PutR was identified downstream of the putAP genes and a mutational analysis revealed that the PutR protein was also involved in regulating the putAP transcription by activating Pput promoter. Although CRP acts as a primary activator and the influence of PutR on Pput is mediated by CRP, the level of Pput activity observed when PutR and CRP functioned together was greater than the sum of Pput activities achieved by each activator alone. Western blot analyses demonstrated that the cellular levels of PutR and CRP were not significantly affected by each other, indicating that PutR and CRP coactivate Pput rather than function sequentially in a regulatory cascade. Two adjacent binding sites for PutR mapped by in vitro DNase I protection assays were found to overlap the CRP binding sites and were centred −91.5 (PCBI) and −133.5 bp (PCBII) upstream of the transcription start site of Pput respectively. PutR and CRP bind to the sites cooperatively and a dissection of the role of the binding sites revealed that CRP at PCBI plays the most crucial role in the activation of Pput. Accordingly, the present results revealed that PutR and CRP coactivate the expression of Pput and exert their effect by cooperatively binding to the promoter.
Candida albicans SET1 encodes a histone 3 lysine 4 methyltransferase that contributes to the pathogenesis of invasive candidiasis
Authors: Raman Suresh Babu , Nguyen M. Hong , Zhang Zongde , Cheng Shaoji , Jia Hong Yan , Weisner Nghe , Iczkowski Kenneth , Clancy Cornelius J.
Published: March 2006

Candida albicans causes diverse mucosal and systemic diseases. Although this versatility likely depends upon carefully co‐ordinated gene expression, epigenetic regulation in C. albicans remains poorly characterized. Screening a genomic expression library, we identified C. albicans Set1p as an immunogenic protein with homology to a lysine histone methyltransferase of Saccharomyces cerevisiae. In this study, we demonstrated that total immunoglobulin, IgG and IgM titers against a unique Set1p N‐terminal fragment were significantly higher among patients with disseminated candidiasis (DC) or oropharyngeal candidiasis than controls. Disruption of SET1 resulted in complete loss of methylation of histone 3 at lysine residue 4, hyperfilamentous growth under embedded conditions, less negative cell surface charges and diminished adherence to epithelial cells, effects that were reversed upon gene re‐insertion at a disrupted locus. During murine DC, the null mutant was associated with prolonged survival and lower tissue burdens. Taken together, our findings suggest that SET1 regulates multiple processes important to the pathogenesis of candidiasis. The Set1p N‐terminal fragment does not exhibit significant homology to eukaryotic or microbial proteins, and might represent a novel therapeutic, preventive or diagnostic target.
Hierarchical involvement of various GGDEF domain proteins in rdar morphotype development of Salmonella enterica serovar Typhimurium
Authors: Kader Abdul , Simm Roger , Gerstel Ulrich , Morr Michael , Römling Ute
Published: March 2006

GGDEF and EAL domain proteins are involved in the turnover of the novel secondary messenger cyclic‐di(3′→5′)‐guanylic acid (c‐di‐GMP) in many bacteria. In this work the role of the 12 GGDEF domain proteins encoded by the Salmonella enterica serovar Typhimurium (S. Typhimurium) chromosome in rdar morphotype development was investigated. Previously, it was shown that the GGDEF domain protein AdrA activated the biosynthesis of cellulose by production of c‐di‐GMP. Enhancement of the c‐di‐GMP levels by overexpression of the GGDEF domain protein AdrA did lead to the activation of curli fimbriae biosynthesis through the elevated expression of CsgD and CsgA. Although knock‐out of the chromosomal copy of adrA influenced CsgA expression, CsgD expression was not altered, although more than half of the total cellular c‐di‐GMP was produced by AdrA at 16 h of growth. On the other hand, chromosomally encoded GGDEF–EAL domain proteins STM2123 and STM3388 were required to additively activate CsgD expression on a transcriptional and post‐transcriptional level. Enhanced c‐di‐GMP levels did overcome temperature regulation of rdar morphotype expression by activation of curli fimbriae as well as cellulose biosynthesis through CsgD expression. Thus in the regulatory cascade leading to rdar morphotype expression c‐di‐GMP activates several subsequent steps in the network.
What is life? The paradigm of DNA and protein cooperation at high local concentrations
Authors: Müller‐Hill Benno
Published: March 2006

Many chemical reactions need high concentrations of the molecules involved in order to work efficiently. It is usually impossible for the cell to achieve the necessary high concentrations of all relevant molecules in unconfined solutions but this becomes possible if the high concentration is restricted around a relevant molecule. High local concentrations of interacting molecules have been observed many times in many different biological systems. The examples of Lac and Lambda repressors of Escherichia coli are presented and discussed here as useful paradigms of mechanisms for achieving high local concentrations of interacting protein protomers.
Flk prevents premature secretion of the anti‐σ factor FlgM into the periplasm
Authors: Aldridge Phillip , Karlinsey Joyce E. , Becker Eric , Chevance Fabienne F.V. , Hughes Kelly T.
Published: March 2006

The flk locus of Salmonella typhimurium was identified as a regulator of flagellar gene expression in strains defective in P‐ and l‐ring formation. Flk acts as a regulator of flagellar gene expression by modulating the protein levels of the anti‐σ28 factor FlgM. Evidence is presented which suggests that Flk is a cytoplasmic‐facing protein anchored to the inner membrane by a single, C‐terminal transmembrane‐spanning domain (TMS). The specific amino acid sequence of the TMS is not essential for Flk activity, but membrane anchoring is essential. Membrane fractionation and visualization of protein fusions of green fluorescent protein derivatives to Flk suggested that the Flk protein is present in the membrane as punctate spots in number that are much greater than the number of flagellar basal structures. The turnover of the anti‐σ28 factor FlgM was increased in flk mutant strains. Using FlgM–β‐lactamase fusions we show the increased turnover of FlgM in flk null mutations is due to FlgM secretion into the periplasm where it is degraded. Our data suggest that Flk inhibits FlgM secretion by acting as a braking system for the flagellar‐associated type III secretion system. A model is presented to explain a role for Flk in flagellar assembly and gene regulatory processes.
Oesophago‐gastric junction opening function: assessment using ultrasound imaging and the effects of atropine
Authors: Liu J. , Takeda T. , Dogan I. , Bhargava V. , Mittal R. K.
Published: March 2006

Abstract  Relaxation and opening of the oesophago‐gastric junction (OGJ) is crucial for oesophageal transport. A novel ultrasound technique was used to determine OGJ opening, before and after atropine, in 12 normals. An ultrasound probe, a solid‐state pressure transducer and an infusion tube were placed inside a 20‐mm diameter bag, which was placed across the OGJ. At various bag pressures ultrasound transducer was pulled across the bag. Acquired B‐mode ultrasound images were converted into M‐mode image to display the oesophagus, OGJ and stomach. At low bag‐pressure (<20 mmHg), the OGJ but not oesophagus and stomach, is collapsed around the bag. Increasing bag pressure results in gradual opening of the OGJ from distal end. M‐mode image identified the narrowest region of OGJ and corresponding cross‐sectional area (CSA) was measured. Mean bag pressure to initial OGJ opening was 18 mmHg. Linear relationship between bag‐pressure and OGJ‐CSA was observed. Atropine reduced opening bag pressure and shifted the OGJ pressure‐CSA curve upward without altering slope, i.e. compliance. Our novel ultrasound technique to study the OGJ opening function shows two distinct components; firstly, related to the tonic OGJ contraction and secondly, to passive or viscoelastic properties of the OGJ.
In vitro‐Generated Viral Double‐Stranded RNA in Contrast to Polyinosinic : Polycytidylic Acid Induces Interferon‐α in Human Plasmacytoid Dendritic Cells
Authors: Löseke S. , Grage‐Griebenow E. , Heine H. , Wagner A. , Akira S. , Bauer S. , Bufe A.
Published: March 2006

Double‐stranded RNA (dsRNA) arises in the cytoplasm during viral replication and was shown to participate in the interferon (IFN)‐α induction process. Besides the intracellular recognition, released dsRNA from dying, infected cells can function as a pathogen‐associated molecular pattern (PAMP) for the innate immune system. In the present study, in vitro‐generated dsRNA fragments of genomic sequences of Newcastle disease virus were used to induce IFN‐α release in human peripheral blood mononuclear cells (PBMC), in immature myeloid dendritic cells (mDC) and in immature plasmacytoid DC (pDC). The extracellular administration of dsRNA fragments but not the application of the corresponding single‐stranded RNA (ssRNA) strands led to an IFN‐α production in PBMC. The synthetic dsRNA analogue polyinosinic acid : polycytidylic acid [Poly(I : C)] could only stimulate IFN‐α production in enriched mDC but not in pDC. In contrast, dsRNA fragments induced IFN‐α only in pDC. Complexation of dsRNA fragments with transfection reagents increased the efficiency of IFN‐α induction and commuted ssRNA molecules into IFN‐α inducers. However, stimulation of in vitro‐generated murine Toll‐like receptor 7 (TLR7) knockout DC and human TLR‐transfected HEK293 cells with dsRNA fragments gave no evidences for the involvement of pDC‐specific TLR7 or TLR9 in the observed IFN‐α induction.
Modelling the long‐term fluvial erosion of the River Somme during the last million years
Authors: Gargani J. , Stab O. , Cojan I. , Brulhet J.
Published: March 2006

A process‐based model that simulates fluvial erosion in the River Somme Valley over the last million years is presented here. The model takes into account lithology and climatic influences and allows the simulating of undercapacity and overcapacity sediment transport behaviour. The model has been calibrated to a family of terraces within the River Somme Valley. When matched to this field data, simulation trials suggest that bedrock incision occurred principally from 120 to 60–40 kyr during the last climatic cycle and before the last glaciation. The impact of a progressive tectonic uplift (c. 60 m over c. 1 million years) on the River Somme has also been studied here. Extended over a longer period of time, the simulations suggest that 1 million years ago the profile of the River Somme had a lower slope gradient than today, with little relief throughout the Paris Basin.
Multiple causes of Earth's earliest global glaciation
Authors: Melezhik Victor A.
Published: March 2006

In the context of Earth System evolution, the causal factors driving the Palaeoproterozoic Huronian global glaciations occupy a central position. The rise of O2 at 2320 Ma, which eliminated most of the methane, was not apparently a single cause triggering the glaciation. At c. 2450 Ma mantle‐plume‐driven continental uplifts led to the emplacement of voluminous continental flood‐basalts in low latitudes that were subsequently dissected by rifting. Major topographical features and continental drainage patterns were most likely similar to those in younger continental flood‐basalt provinces and would have enabled deep weathering and erosion of extensive basalt‐covered continental areas. Intense consumption of atmospheric CO2 by silicate weathering of fresh basaltic surfaces would have been further amplified by a constant organic carbon burial rate. These factors, similar to those of younger glacial periods, in combination with the diminished CH4 greenhouse led to an onset of global cooling at the million‐year timescale.