bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation between adsorbed and precipitated sulphate in soils and at micro‐sites of soil aggregates by sulphur K‐edge XANES
Authors: Prietzel J. , Thieme J. , Herre A. , Salomé M. , Eichert D.
Published: March 2008

To investigate the potential of synchrotron‐based X‐ray Absorption Near‐Edge Structure spectroscopy (XANES) at the sulphur (S) K‐edge for a discrimination of adsorbed and precipitated sulphate in soils and soil particles, XANES spectra of ionic sulphate compounds and Al/Fe hydroxy sulphate minerals were compared with spectra of SO42− adsorbed to ferrihydrite, goethite, haematite, gibbsite or allophane. Ionic sulphate and hydroxy sulphate precipitates had broader white‐lines (WL) at 2482.5 eV (full width at half maximum (FWHM) of edge‐normalized spectra, 2.4–4.2 eV; Al hydroxy sulphates, 3.0 eV) than SO42− adsorbed to Al/Fe oxyhydroxides or allophane (FWHM, 1.8–2.4 eV). The ratio of the white‐line (WL) height to the height of the post‐edge feature at 2499 eV (WL/PEF) was larger for SO42− adsorbed to Al/Fe oxyhydroxides or allophane (8.1–11.9) than for Al/Fe hydroxy sulphates and ionic sulphates (3.9–5.7). The WL/PEF ratio of edge‐normalized S K‐edge XANES spectra can be used to distinguish adsorbed from precipitated SO42− in soils and also at microsites of soil particles. The contribution of adsorbed and precipitated SO42− to the total SO42− pool can be roughly quantified. Adsorbed ester sulphate may result in overestimation of precipitated SO42−. The spectra of most soils could be fitted by linear combination fitting (LCF), yielding a similar partitioning between adsorbed and precipitated SO42− as an evaluation of the WL/PEF ratio. The SO42− pool of German forest soils on silicate parent material in most cases was strongly dominated by adsorbed SO42−; however, in three German forest soils subject to elevated atmospheric S deposition, a considerable portion of the SO42− pool was precipitated SO42−, most likely Al hydroxy sulphate. The same is true for Nicaraguan Eutric and Vitric Andosols subject to high volcanogenic S input. In the subsoil of the Vitric Andosol, adsorbed SO42− and Al hydroxy sulphate coexist on a micron scale.
Gravimetric study of a potential mineral deposit in the Itapororoca region, Brazil
Authors: Mantovani Marta S.M. , Shukowsky Wladimir , De Brito Neves B.B. , Rugenski André
Published: March 2008

A semi‐detailed gravity survey was carried out over an area of 650 km2 localized in the Eo‐Neoproterozoic coastal zone of Paraiba State where 548 new gravity stations were added to the existing database. Gravity measurements were made with a LaCoste and Romberg model G meter with a precision of 0.04 mGal. The altitude was determined by barometric levelling with a fixed base achieving a 1.2 m measure of uncertainty, corresponding to an overall accuracy of 0.24 mGal for the Bouguer anomaly. The residual Bouguer map for a 7th degree regional polynomial showed a circumscribed negative anomaly coincident with a localized aero‐magnetic anomaly and with hydro‐thermally altered outcrops, near the city of Itapororoca. The 3D gravity modelling, constrained by geologic mapping was interpreted as a low density, fractured and/or altered material with a most probable volume of approximately 23 km3, extending to about 8,500 m depth. This result is in accordance with a volcanic body associated with hydrothermal processes accompanied by surface mineralization evidence, which may be of interest to the mining industry.
Examination of the potential relationship between droughts, sulphate and dissolved organic carbon at a wetland‐draining stream
Authors: EIMERS M. CATHERINE , WATMOUGH SHAUN A. , BUTTLE JAMES M. , DILLON PETER J.
Published: March 2008

Rising dissolved organic carbon (DOC) concentrations observed at a number of sites in the northern hemisphere over recent decades are the subject of much debate, and recent reports suggest a link between DOC patterns in surface waters and changes in sulphate (SO4) related to droughts or deposition. In order to investigate the potential influence of changes in SO4 concentration on DOC patterns in south‐central Ontario, we used long‐term (1980–2001) stream monitoring data from a wetland‐dominated catchment (Plastic Lake‐1 subcatchment, PC1) that has been the focus of intensive investigations of both SO4 and DOC dynamics. Annual average volume‐weighted DOC concentration increased significantly between 1980 and 2001, whereas SO4 concentration declined, but the decrease was not significant due to large increases in SO4 that occurred during drought years. There was no relationship between SO4 and DOC in annual data series; however, seasonal analyses indicated significant negative correlations between SO4 and DOC concentrations in spring (March–April–May), summer (June–July–August) and fall (September–October–November). In spring, DOC concentration was negatively correlated with flow whereas SO4 concentrations increased with flow, and their opposing relationships with discharge explain the negative correlation between SO4 and DOC in this season. In summer and fall, low SO4 concentrations occur during periods of low flow as a result of microbial SO4 reduction, whereas correspondingly high DOC concentrations in the summer and fall can be attributed to optimal conditions (i.e. stagnant flow, warm temperatures) for DOC production in the wetland. Increases in SO4 (and acidity) following droughts were not associated with declines in DOC; instead the primary impact of droughts on DOC was to limit DOC export due to diminished stream flow. Rather than an acidification effect, we suggest that negative relationships between SO4 and DOC were either directly (spring) or indirectly (summer/fall) caused by underlying relationships with hydrology.
Efficacy and safety of OCTANINE F in children with haemophilia B
Authors: KLUKOWSKA A. , LAGUNA P. , SVIRIN P. , SHILLER E. , VDOVIN V.
Published: March 2008

Summary.  OCTANINE F is a high‐purity blood clotting factor IX concentrate that has been shown to be effective and safe in adults with haemophilia B. At present, there are no prospective clinical study data on FIX replacement therapy in young children. The primary objective of this trial was to investigate the immunogenicity of OCTANINE F in children aged <6 years with haemophilia B. Secondary objectives were to assess the efficacy, viral safety and tolerability of OCTANINE F in this patient population. Twenty‐five children aged <6 years with moderate or severe haemophilia B, including six who were previously untreated and 13 who had less than previous 50 exposure days were assigned to prophylactic or on‐demand treatment with OCTANINE F over a 12‐ to 24‐month period. Immunogenicity was assessed at baseline, during the treatment period and at the end of treatment by monitoring the levels of inhibitor. OCTANINE F was not associated with the development of an inhibitor in any patient during the study; all patients had a FIX inhibitor level of <0.4 Bethesda units (BU) for all samples taken throughout the study. The efficacy of OCTANINE F was rated as excellent in 96.4% of 499 bleeding episodes and tolerability was rated as very good in 97% of 1684 injections. OCTANINE F was shown to be effective and well tolerated in children aged <6 years with moderate or severe haemophilia B, including previously untreated patients, with no reported cases of FIX inhibitors or thrombotic events.
Italian Registry of Haemophilia and Allied Disorders. Objectives, methodology and data analysis
Authors: IORIO A. , OLIOVECCHIO E. , MORFINI M. , MANNUCCI P. M. ,   THE ASSOCIATION OF ITALIAN HEMOPHILIA CENTRES DIRECTORS
Published: March 2008

Summary.  National haemophilia registries are powerful instruments to support health care and research. A national registry was established in Italy by the Ministry of Health until 1999. Since 2003 the Italian Association of Haemophilia Centres (AICE) started a new programme aiming at building up the Italian Registry of Haemophilia and Allied Disorders. The AICE identified an expert panel to steer the registry. A computer software to assist patient management was developed and all the AICE‐affiliated haemophilia treatment centres (HTC) were prompted to adopt it. Twice a year a predefined set of anonymized data is centralized and merged into a national database. Duplicated entries are managed through a confidentiality sparing mechanism. The database covers sociodemographic, clinical, laboratory and treatment data. A subset of data are shared with the Ministry of Health (Istituto Superiore di Sanità,ISS).Overall, data were collected six times by 43 of 49 HTC; 41 centres updated their patients’ records up to December 2006. The database contains 6632 unique records, 442 of them referring to dead patients. Database growth and missing data clearance showed a constantly positive trend over time. The database has collected records of the following alive patients – haemophilia A: 1364 severe, 398 moderate and 935 mild; haemophilia B: 231 severe, 138 moderate and 204 mild; von Willebrand’s disease: 1208 type 1, 346 type 2 and 96 type 3. Inhibitor patients were 296 (of which 194 high responders and 65 low responders).The Italian registry run by AICE adds to the list of the available national haemophilia registries and is intended to establish treatment guidelines and foster research projects in Italy.
Differential and cell‐type specific regulation of responses to Toll‐like receptor agonists by ISO‐1
Authors: West Peter W. , Parker Lisa C. , Ward Jon R. , Sabroe Ian
Published: March 2008

Macrophage migration inhibitory factor (MIF) plays vital roles in the regulation of responses to stimuli acting via Toll‐like receptor (TLR)‐4. Recently, a specific small molecule inhibitor of MIF (ISO‐1) has been described. We investigated the effects of ISO‐1 on TLR responses in primary human monocytes and monocyte‐derived macrophages (MDM). In monocytes, ISO‐1 caused marked suppression of TLR4‐induced proinflammatory cytokine production, and to a lesser extent suppression of TLR2‐induced responses. The lipopolysaccharide (LPS)‐induced activation of cocultures of monocytes and endothelial cells was strongly inhibited by ISO‐1. Suppression of monocyte TLR4 signalling by ISO‐1 was associated with alterations in extracellular signal‐related kinase (ERK)‐1/2 activation status. Previously, regulation of TLR4 signalling by MIF has been noted to be through control of TLR4 expression, but we observed that the actions of ISO‐1 were mediated without changes in cell surface TLR4 levels. In contrast, ISO‐1 pretreatment did not inhibit responses of MDM to LPS. ISO‐1 is a promising parent molecule which inhibits TLR‐induced ERK activation and inflammatory cytokine production in monocytes, whose role may be complicated by cell‐type specificity.
Patterns of ‘balancing between hope and despair’ in the diagnostic phase: a grounded theory study of patients on a gastroenterology ward
Authors: Giske Tove , Artinian Barbara
Published: March 2008

Title.  Patterns of ‘balancing between hope and despair’ in the diagnostic phase: a grounded theory study of patients on a gastroenterology ward

Aim.  The aim of the study was to learn how patients going through the diagnostic phase experienced and handled their situation.

Background.  Many studies report about the stressful diagnostic phase; however, none has presented a conceptual theory where the concepts are sufficiently related to each other. The Theory of Preparative Waiting has previously been published as a descriptive grounded theory and describes the experience of a group of gastroenterology patients going through the diagnostic phase.

Method.  A classical grounded theory design was used, with data derived from 18 in‐depth interviews with 15 patients in a gastroenterology ward at a Norwegian University Hospital. Interviews were conducted during 2002–2003.

Findings.  Participants’ main concern was found to be how they could prepare themselves for the concluding interview and life after diagnosis. The theoretical code of ‘balancing’ had four patterns; controlling pain, rational awaiting, denial, and accepting. These patterns of ‘balancing’ guided how participants used the categories of ‘Preparative Waiting Theory’‘seeking and giving information’, ‘interpreting clues’, ‘handling existential threats’ and ‘seeking respite’. Patterns were strategies, so one person could use more than one pattern.

Conclusion.  The diagnostic phase was a difficult time for the participants and the ‘Preparative Waiting Theory’ can assist nurses in assessing how patients prepare themselves differently for getting a diagnosis. All patients would find it helpful to be followed up by a designated contact person at the ward; however, patients using mostly the patterns of controlling pain and denial would benefit most from such support.
Patients’ experiences of learning clean intermittent self‐catheterization: a qualitative study
Authors: Logan Karen , Shaw Chris , Webber Irene , Samuel Sandra , Broome Lynne
Published: March 2008

Title.  Patients’ experiences of learning clean intermittent self‐catheterization: a qualitative study

Aim.  This paper is a report of a study to explore the experiences of learning to carry out clean intermittent self‐catheterization and user views of service provision.

Background.  This treatment imposes a variety of challenges to users, both physical and emotional. Safety, infection rates and complications have been investigated, but the practicalities of learning and performing self‐catheterization have not been addressed. What is currently known about the topic from a user perspective is based on audit, small projects or anecdotal reports provided by continence advisers.

Method.  In‐depth interviews were carried out in 2006 with eight men and seven women, aged 33–81 years (median 65), and carrying out self‐catheterization for a variety of reasons. A grounded theory framework was used.

Findings.  Themes identified were psychological issues, physical problems and service interaction. The communication skills of nurses helped facilitate the learning experience. In conjunction with nurses’ skills, a friendly relaxed approach alleviated embarrassment and anxiety, thus facilitating information exchange and retention of information.

Conclusion.  Adequate information and thorough instruction by healthcare professionals helps empower people to take control and master the treatment, with potential contribution to ongoing compliance and long‐term urinary tract health. Development of a policy supporting evidence‐based care and a consistent teaching programme is highly recommended for use where this treatment is regularly employed.
The qualitative content analysis process
Authors: Elo Satu , Kyngäs Helvi
Published: March 2008

Title.  The qualitative content analysis process

Aim.  This paper is a description of inductive and deductive content analysis.

Background.  Content analysis is a method that may be used with either qualitative or quantitative data and in an inductive or deductive way. Qualitative content analysis is commonly used in nursing studies but little has been published on the analysis process and many research books generally only provide a short description of this method.

Discussion.  When using content analysis, the aim was to build a model to describe the phenomenon in a conceptual form. Both inductive and deductive analysis processes are represented as three main phases: preparation, organizing and reporting. The preparation phase is similar in both approaches. The concepts are derived from the data in inductive content analysis. Deductive content analysis is used when the structure of analysis is operationalized on the basis of previous knowledge.

Conclusion.  Inductive content analysis is used in cases where there are no previous studies dealing with the phenomenon or when it is fragmented. A deductive approach is useful if the general aim was to test a previous theory in a different situation or to compare categories at different time periods.
Turnover intention in new graduate nurses: a multivariate analysis
Authors: Beecroft Pauline C. , Dorey Frederick , Wenten Madé
Published: March 2008

Title.  Turnover intention in new graduate nurses: a multivariate analysis

Aim.  This paper is a report of a study to determine the relationship of new nurse turnover intent with individual characteristics, work environment variables and organizational factors and to compare new nurse turnover with actual turnover in the 18 months of employment following completion of a residency.

Background.  Because of their influence on patient safety and health outcomes nurse turnover and turnover intent have received considerable attention worldwide. When nurse staffing is inadequate, especially during nursing shortages, unfavourable clinical outcomes have been documented.

Method.  Prospective data collection took place from 1999 to 2006 with 889 new paediatric nurses who completed the same residency. Scores on study instruments were related to likelihood of turnover intent using logistic regression analysis models. Relationships between turnover intent and actual turnover were compared using Kaplan–Meier survivorship.

Results.  The final model demonstrated that older respondents were more likely to have turnover intent if they did not get their ward choice. Also higher scores on work environment and organizational characteristics contributed to likelihood that the new nurse would not be in the turnover intent group. These factors distinguish a new nurse with turnover intent from one without 79% of the time. Increased seeking of social support was related to turnover intent and older new graduates were more likely to be in the turnover intent group if they did not get their ward choice.

Conclusion.  When new graduate nurses are satisfied with their jobs and pay and feel committed to the organization, the odds against turnover intent decrease.
Clinical judgement and decision‐making in nursing – nine modes of practice in a revised cognitive continuum
Authors: Standing Mooi
Published: March 2008

Title. Clinical judgement and decision‐making in nursing – nine modes of practice in a revised cognitive continuum

Aim. This paper is a report of an evaluation of cognitive continuum theory and identification of revisions required for application to clinical judgement and decision‐making in nursing.

Background. The importance of nurses’ developing and applying sound clinical judgement is reflected in an international classification of nursing practice. Cognitive continuum theory synthesizes rival and complementary approaches to decision theory in an accessible format, which has been applied in medicine, and various nursing scholars have advocated its use to enhance the effectiveness of nurses’ clinical judgement and decision‐making.

Method. Parse’s structure and process criteria are applied in critiquing the relevance of cognitive continuum theory to nursing.

Findings. Cognitive continuum theory illustrates how different judgement tasks are suited to different thought processes and how matching the two can optimize decision‐making. However, existing modes of inquiry applied to medicine emphasize experimental research, ignoring many alternative approaches used in nursing. A revised version of the cognitive continuum is developed, incorporating examples of nursing judgements and decisions, a broader evidence base, an ethical dimension, and evaluative competence criteria.

Conclusion. The revised cognitive continuum promotes awareness of the nature and the variety of patient‐centred judgement tasks and decisions in nursing, how to select the most suitable intervention tactic from available options, and the fallibility of all forms of human judgement from intuitive/experiential to analytic/rational. Hence, it is recommended for use as an educational tool and practice guide to facilitate theory development and the practice of judgement and decision‐making in nursing.
Correlates of post‐hospital physical function at 1 year in skilled nursing facility residents
Authors: Lee Jia , Rantz Marilyn
Published: March 2008

Title.  Correlates of post‐hospital physical function at 1 year in skilled nursing facility residents

Aim.  This paper is a report of a study to examine the relationship between health‐related admission factors and post‐hospital physical function at 3, 6, 9 and 12 months in older adult nursing facility residents.

Background.  Physical functional decline is a significant health problem for older adults and has far‐reaching effects. In particular, the immediate post‐hospital period is a high‐risk time, because shortened hospital stays make it likely that older patients are discharged in a state of incomplete recovery.

Method.  Data spanning from July 2002 to June 2005 were extracted from a comprehensive assessment tool, the Minimum Data Set, for 38,591 beneficiaries of a federal health insurance programme covering older adults in the Midwestern region of the United States of America. We investigated relationships between admission factors and post‐hospital physical function at 3, 6, 9 and 12 months. The admission factors were health‐related variables assessed at the time of skilled nursing facility admission from an acute care hospital.

Findings.  The most important admission factors related to post‐hospital physical function at 3, 6, 9 and 12 months were baseline physical function, urinary incontinence and pressure ulcer. Cognitive impairment at admission demonstrated a stronger relationship with poor physical function as resident length of stay increased.

Conclusion.  Nurses in skilled nursing facilities should screen post‐hospital older adults for risk of physical functional decline at admission using identified admission factors. For continuous nursing care, older adults need to be assessed at least once a month during the first 3 months after hospital discharge.
Measuring community nurses’ job satisfaction: literature review
Authors: Caers Ralf , Du Bois Cindy , Jegers Marc , De Gieter Sara , De Cooman Rein , Pepermans Roland
Published: March 2008

Title.  Measuring community nurses’ job satisfaction: literature review

Aim.  This paper is a report of a review of the literature on community nurses’ job satisfaction, including research using different scales and settings, what is known to date and directions for future research.

Background.  Job satisfaction is one of the strongest predictors of intent to stay and retention of nurses. An adequate understanding of the sources of job satisfaction and their importance can aid policymakers in the community nursing setting to cope with the growing demand for its services.

Data sources.  A database of papers was established using ISI Web of Knowledge. Cited references were used to expand the database. Journals adding to the database were scanned for related research. This technique was repeated until no additional papers could be found.

Findings.  Twelve job satisfaction scales were found, with striking differences in methodology, settings and sample characteristics of the studies concerned. A wide variety of job satisfaction and dissatisfaction sources is identified, but little is known on their relative importance. The Measure of Job Satisfaction and the Home Healthcare Nurses’ Job Satisfaction Scale prove highly reliable and applicable.

Conclusion. Findings on the level and sources of community nurses’ job satisfaction are ambiguous. Of all the scales reviewed, the Home Healthcare Nurses’ Job Satisfaction Scale seems most promising for use in future research, based on its strong psychometric properties and its specificity for the community nursing setting.
Representations of disability in nursing and healthcare literature: an integrative review
Authors: Boyles Christina McMillan , Bailey Patricia H. , Mossey Sharolyn
Published: March 2008

Title.  Representations of disability in nursing and healthcare literature: an integrative review

Aim.  This paper is a report of an integrative review to explore the way in which disability has been considered in the multidisciplinary health and nursing literature.

Background.  In the multidisciplinary health and nursing literature, two ways are presented in which disability can be understood: the traditional, functional perspective and a more contemporary, social perspective.

Data sources.  Computerized databases of the CINAHL, Proquest Nursing and Allied Health Sources, EBSCO and Evidence Based Medicine Reviews Multifile and Cochrane databases were conducted for papers published in English in the period 1963–2007 using the keywords ‘models of disability’, ‘disability and nursing research’ and ‘theories of disability’.

Methods.  An integrative review was performed and, of the 11,578 papers identified, 65 were included.

Results.  The concept of functional disability refers to an individual who is physically ‘disabled’ and unable to perform expected roles. The concepts of social stigmatization and normalcy are associated with functional disability. In contrast, social disability concerns functional limitations within an individual’s experience of living with disability, examining how socially constructed barriers actually ‘disable’ people. Conventionally, disability research has been conducted from an etic perspective. Researchers contend that a shift towards an understanding from the emic perspective is needed for disability research to be emancipatory.

Conclusion.  Adoption of a social perspective is necessary to inform an understanding of disability that addresses stigmatization and oppression. Research‐informed nursing practice, complemented by supportive health and social policies, could transform the experience of living with disability.
Using quantitative real‐time PCR to detect salmonid prey in scats of grey Halichoerus grypus and harbour Phoca vitulina seals in Scotland – an experimental and field study
Authors: Matejusová I. , Doig F. , Middlemas S. J. , Mackay S. , Douglas A. , Armstrong J. D. , Cunningham C. O. , Snow M.
Published: March 2008

There is considerable debate over the impact of seal predation on salmonid populations in both the Atlantic and Pacific oceans. Conventional hard‐part analysis of scats has suggested that salmonids represent a minor component of the diet of grey seals (Halichoerus grypus) and harbour seals (Phoca vitulina) in the UK. However, it is unclear whether this is an accurate reflection of the diet or due to methodological problems. To investigate this issue, we applied quantitative PCR (qPCR) to examine the presence of salmonids in the diet of seals in the Moray Firth, UK, during the summers of 2003 and 2005.

Two qPCR assays were designed to detect Atlantic salmon Salmo salar and sea trout Salmo trutta DNA in field samples and experimentally spiked scats. The proportion of scats sampled in the field that were positive for salmonid DNA was low (ª10%). However, the DNA technique consistently resulted in more positive scats than when hard‐part analysis was used.

An experimental study using spiked scat material revealed a highly significant negative relationship between Ct values obtained from the Atlantic salmon qPCR assay and the proportion of Atlantic salmon material added to scats. The Ct value denotes the cycle number at which the increasing fluorescence signal of target DNA crosses a threshold value. Ct values from field‐collected seal scats suggested they contained a very low concentration of salmonid remains (1–5%) based on an approximate calibration curve constructed from the experimental data.

Synthesis and applications. The qPCR assay approach was shown to be highly efficient and consistent in detection of salmonids from seal scats, and to be more sensitive than conventional hard‐parts analysis. Nevertheless, our results confirm previous studies indicating that salmonids are not common prey for seals in these Scottish estuaries. These studies support current management practice, which focuses on control of the small number of seals that move into key salmonid rivers, rather than targeting the larger groups of animals that haul‐out in nearby estuaries.
Escape and establishment of transgenic glyphosate‐resistant creeping bentgrass Agrostis stolonifera in Oregon, USA: a 4‐year study
Authors: Zapiola M. L. , Campbell C. K. , Butler M. D. , Mallory‐Smith C. A.
Published: March 2008

Gene flow from transgenic crops to feral populations and naturalized compatible relatives has been raised as one of the main issues for the deregulation of transgenic events. Creeping bentgrass, Agrostis stolonifera L., is a perennial, outcrossing grass that propagates by seeds and stolons. Transgenic Roundup Ready® glyphosate‐resistant creeping bentgrass (GRCB), which is currently under USDA‐APHIS regulated status, was planted in 2002 on 162 ha within a production control area in Oregon, USA.

We conducted a study to assess transgene flow from the GRCB fields. A survey within and around the production control area was performed during the year when the GRCB fields produced seed and for 3 years after the fields were taken out of production. Transgene flow was determined by testing creeping bentgrass and its relatives for expression of the glyphosate resistance transgene.

While GRCB seed‐production practices were strictly regulated, evidence of transgene flow was found in all years. In 2006, 3 years after the transgene source fields were taken out of production and a mitigation programme was initiated, 62% of the 585 creeping bentgrass plants tested in situ were glyphosate‐resistant (GR). Our results document not only the movement of the glyphosate resistance transgene from the fields, but also the establishment and persistence of high frequencies of GR plants in the area, confirming that it was unrealistic to think that containment or eradication of GRCB could be accomplished.

Synthesis and applications: These findings highlight the potential for transgene escape and gene flow at a landscape level. The survey provides empirical frequencies that can be used to design monitoring and management methods for genetically engineered (GE) varieties of outcrossing, wind‐pollinated, perennial grasses and to evaluate the potential for coexistence of GE and non‐GE grass seed crops. Such information should also be used in the decision‐making process for authorization of field trials and deregulation of genetic engineering events.
Dietary shift of an invasive predator: rats, seabirds and sea turtles
Authors: Caut Stéphane , Angulo Elena , Courchamp Franck
Published: March 2008

Rats have reached about 80% of the world's islands and are among the most successful invasive mammals. Rats are opportunistic predators that are notorious for their impact on a variety of animal and plant species. However, little documented evidence on the complexities of these interactions is available.

In our study, we assessed the impact of black rats Rattus rattus introduced on a small uninhabited island with a relatively simple ecosystem, Surprise Island, New Caledonia. We also compared the diet of R. rattus in the presence and absence of breeding seabirds, assessing the dietary compensation for this potentially important food source. From 2002 to 2005, we used live trapping studies combined with stable isotope analysis and conventional diet analyses (direct observations, gut and faecal contents) to characterize the diet of rats.

Our results suggest a heavy predatory impact on seabirds, which could constitute as much as 24% of the rat diet. Moreover, in the absence of birds, rats compensated marginally by preying more heavily on other components of their diet but mostly acquired a new resource. They shifted their diet by preying heavily upon another endangered species, the hatchlings of sea turtles Chelonia mydas, which could constitute the main resource in the diet of R. rattus in those periods. Abundance, body condition and distribution of the rats were consistent with heavy predation upon this additional resource.

Synthesis and applications. In island ecosystems invasive rats prey mainly upon seabird eggs and chicks, thereby threatening their populations. Although rats are certainly capable of surviving on terrestrial foods outside the seabird nesting season, their ability to prey upon ephemeral but abundant resources, such as hatchling sea turtles, may contribute to maintaining their populations. This may explain their success on Surprise Island, an ecosystem of extreme conditions, and suggests that biologists and managers working with threatened species should be aware of the possibility of temporary diet shifts by introduced rodents that may cause unexpected heavy predation on these species. This dietary shift from one endangered taxa to another has major implications for the conservation of seabirds and sea turtles world‐wide and more generally for the biodiversity of invaded insular communities.
Canopy shade and the successional replacement of tamarisk by native box elder
Authors: Dewine J. M. , Cooper D. J.
Published: March 2008

Tamarisk species (Tamarix ramosissima Ledeb., T. chinensis Lour., T. gallica L. and hybrids) have invaded riparian areas throughout western North America, resulting in expansive control efforts. Tamarisk is a relatively recent addition to North American plant communities, and competitive and successional processes are still developing. Box elder (Acer negundo L. var. interius (Britt.) Sarg.) is a native competitor found in canyons throughout western North America. We investigated the establishment chronology, competition and comparative shade tolerances of tamarisk and box elder to determine the superior competitor and to predict successional trajectories in mixed stands.

Competition was studied through neighbourhood analysis, and successional trends were analysed through dendrochronology in the canyons of Dinosaur National Monument, CO, USA. The shade tolerance of mature tamarisk was studied by enclosing individual plants in shade cloth for two growing seasons. The comparative shade tolerances of juvenile tamarisk and box elder were studied using five levels of shading in a glasshouse experiment.

Box elder and tamarisk established concurrently, or tamarisk establishment preceded box elder establishment. Box elder was the superior competitor; the presence of canopy box elders within 1 and 2 m was significantly related to tamarisk mortality but not box elder mortality. The presence of canopy tamarisk trees was not related to box elder or tamarisk mortality.

In the field‐based experiment, mature tamarisks were killed when subjected to one to two growing seasons of 98% shade. In the greenhouse‐based experiment, box elder had superior shade tolerance to tamarisk, maintained positive growth and survived under higher shade than tamarisk.

Synthesis and applications. Box elder is a superior competitor to tamarisk, and is capable of establishing under dense tamarisk canopies, overtopping and eventually killing tamarisk. Superior shade tolerance appears to be the mechanism for the successional replacement of tamarisk by box elder. The manipulation of competitive and successional processes through the promotion of box elder and other native tree establishment is suggested as a means of tamarisk control to complement traditional control techniques.
Grasping at the routes of biological invasions: a framework for integrating pathways into policy
Authors: Hulme P. E. , Bacher S. , Kenis M. , Klotz S. , Kühn I. , Minchin D. , Nentwig W. , Olenin S. , Panov V. , Pergl J. , Pyšek P. , Roques A. , Sol D. , Solarz W. , Vilà M.
Published: March 2008

Pathways describe the processes that result in the introduction of alien species from one location to another. A framework is proposed to facilitate the comparative analysis of invasion pathways by a wide range of taxa in both terrestrial and aquatic ecosystems. Comparisons with a range of data helped identify existing gaps in current knowledge of pathways and highlight the limitations of existing legislation to manage introductions of alien species. The scheme aims for universality but uses the European Union as a case study for the regulatory perspectives.

Alien species may arrive and enter a new region through three broad mechanisms: importation of a commodity, arrival of a transport vector, and/or natural spread from a neighbouring region where the species is itself alien. These three mechanisms result in six principal pathways: release, escape, contaminant, stowaway, corridor and unaided.

Alien species transported as commodities may be introduced as a deliberate release or as an escape from captivity. Many species are not intentionally transported but arrive as a contaminant of a commodity, for example pathogens and pests. Stowaways are directly associated with human transport but arrive independently of a specific commodity, for example organisms transported in ballast water, cargo and airfreight. The corridor pathway highlights the role transport infrastructures play in the introduction of alien species. The unaided pathway describes situations where natural spread results in alien species arriving into a new region from a donor region where it is also alien.

Vertebrate pathways tend to be characterized as deliberate releases, invertebrates as contaminants and plants as escapes. Pathogenic micro‐organisms and fungi are generally introduced as contaminants of their hosts. The corridor and unaided pathways are often ignored in pathway assessments but warrant further detailed consideration.

Synthesis and applications.Intentional releases and escapes should be straightforward to monitor and regulate but, in practice, developing legislation has proved difficult. New introductions continue to occur through contaminant, stowaway, corridor and unaided pathways. These pathways represent special challenges for management and legislation. The present framework should enable these trends to be monitored more clearly and hopefully lead to the development of appropriate regulations or codes of practice to stem the number of future introductions.
In search for key biogeochemical factors affecting plant species persistence in heathland and acidic grasslands: a comparison of common and rare species
Authors: Kleijn David , Bekker Renée M. , Bobbink Roland , De Graaf Maaike C. C. , Roelofs Jan G. M.
Published: March 2008

During the last century, many plant species typical of heathland and nutrient‐poor acidic grasslands have become rare whereas others have remained common. Habitat restoration often fails to enhance the rare species, which may in part be caused by the failure to restore the biogeochemical conditions suited to these species. Many soil variables have been shown to affect plant fitness but it is unknown what their relative importance is and whether any biogeochemical variable acts as a key factor constraining the persistence of rare heathland species.

We compiled a data set consisting of 300 vegetation samples and the associated soil chemical properties from a range of studies carried out across the Netherlands. We asked whether growth sites of rare and common species typical of heathland and acidic grasslands differed in their biogeochemical properties, and whether growth sites of rare species displayed less variation in soil biogeochemical variables (e.g. had narrower ecological amplitude).

Regardless of rarity, the species’ growth sites were most accurately described by a curvilinear relationship between pH and Al/Ca ratios. Other soil characteristics did not vary systematically with changing acidity of the soil or the patterns were less pronounced. Acidification will therefore most rapidly and predictably result in an increase in Al/Ca ratio whereas this is not necessarily the case for the other soil variables affecting plant fitness.

The soil ammonium (NH4) concentration and ammonium/nitrate (NH4/NO3) ratio were 3·5 and 3 times higher, respectively, in growth sites of common species compared with those of rare species. No other measured variable differed significantly between rare and common plant species.

On average rare species had a significantly narrower ecological amplitude than common species for soil biogeochemical parameters.

Synthesis and applications. A greater sensitivity to high NH4 concentrations in combination with a narrower ecological tolerance zone for a range of soil biogeochemical factors may explain the demise of rare species adapted to nutrient‐poor acidic habitats in recent decades. Conservation management should aim to restore low NH4 concentrations and NH4/NO3 ratios. Experimental studies indicate that the most effective way to do this is through removal of the topsoil in combination with liming.
Incorporating distance constraints into species distribution models
Authors: Allouche Omri , Steinitz Ofer , Rotem Dotan , Rosenfeld Arik , Kadmon Ronen
Published: March 2008

Species distribution models (SDM) are increasingly applied as predictive tools for purposes of conservation planning and management. Such models rely on the concept of the ecological niche and assume that distribution patterns of the modelled species are at some sort of equilibrium with the environment. This assumption contrasts with empirical evidence indicating that distribution patterns of many species are constrained by dispersal limitation.

We demonstrate that the performance of SDM based on presence‐only data can be significantly enhanced by incorporating distance constraints (functions relating the likelihood of species’ occurrences at a site to the distance of the site from known presence locations) to the modelling procedure. This result is highly consistent for a variety of niche‐based models (ENFA, DOMAIN and Mahalanobis distance), distance functions (nearest neighbour distance, cumulative distance and Gaussian filter) and taxonomic groups (plants, snails and birds, a total of 226 species).

Distance constraints are expected to enhance the accuracy of niche‐based models even in the absence of strong dispersal limitation by accounting for mass effects and spatial autocorrelation in environmental factors for which data are not available.

While distance‐based methods outperformed niche‐based models when all data were used, their accuracy deteriorated sharply with smaller sample sizes. Niche‐based methods are shown to cope better with small sample sizes than distance‐based methods, demonstrating the potential advantage of niche‐based models when calibration data are limited.

Synthesis and applications. Incorporating distance constraints in SDM provides a simple yet powerful method to account for spatial autocorrelation in patterns of species distribution, and is shown empirically to improve significantly the performance of such models. We therefore recommend incorporating distance constraints in future applications of SDM.
The untamed shrew: on the termination of an eradication programme for an introduced species
Authors: Solow Andrew , Seymour Adrian , Beet Andrew , Harris Stephen
Published: March 2008

One option in managing introductions of non‐native pest species is to eradicate the introduced species by trapping or otherwise removing individuals. A central issue in undertaking such a programme is deciding when it is reasonable to terminate the programme because all individuals have been removed. This decision requires knowledge of the probability that complete eradication has been achieved.

 An objective Bayesian method is presented to determine the probability that all individuals of an introduced species have been removed. The method is based on the excess trapping times of individuals beyond a specified threshold, assuming a generalized Pareto distribution for excess trapping time.

 The method is applied to data from an unsuccessful trapping programme of the Asian musk shrew Suncus murinus on the Mauritian island of Ile aux Aigrettes. The results suggest that, had the method been used, managers would have realized that the probability of complete eradication was not high and premature termination could have been avoided.

Synthesis and applications. A central issue facing the manager of an eradication programme for an introduced or pest species is deciding when it is reasonable to terminate the programme because all individuals have been removed. If termination is premature, the programme will fail; if termination is delayed beyond the point of eradication, unnecessary costs will be incurred. The statistical method described here for calculating the probability of complete eradication based on the record of removals provides information that is useful either in an informal assessment of progress or in more formal decision making regarding termination.
Physiological Studies on Early‐blocked Sporulation Mutants of Bacillus subtilis
Authors: Michel Janine F. , Millet Jacqueline
Published: March 2008

Summary. A relationship was observed in Bacillus subtilis between spore formation and the production of two extracellular enzymes, a serine‐proteinase and an esterase. These productions are impaired in 5 different classes of early‐blocked sporulation mutants. The residual activities of these two enzymes vary in proportion from one mutant class to another.

The activity of a third extracellular enzyme, a metal activated proteinase, is slightly impaired if at all in only 2 of the 5 mutant classes. This activity is not required for sporulation, since enzyme loss in one mutant did not affect its ability to sporulate.
Assessment of the Stability of Pasteurized Comminuted Meat Products
Authors: Mol J. H. H. , Timmers C. A.
Published: March 2008

Summary. Data on the occurrence of spores in raw meat materials and in pasteurized meat products are presented. A survey of sporeforming organisms, isolated mainly from spoilt pasteurized meat products, is given. The preparation of a mixed spore suspension and its application to assess the various factors which influence the stability of pasteurized vacuum packed comminuted meat products are described. The incorporation of glucono‐delta‐lactone into meat mixes containing nitrite may improve the stability of the pasteurized products considerably, because it adjusts the pH value to an effective level.
A Note on the Effect of Diluents on the Determination of Viable Numbers of Azotobacteriaceae
Authors: Billson Sylvia , Williams Kay , Postgate J. R.
Published: March 2008

Summary. Azotobacteriaceae suffer dilution shock in physiological saline. Valid plate counts were obtained only when dilutions were made in a salt mixture resembling the growth medium. Dilution shock was progressive and was related to the oxygen sensitivity of the group.
The Effect of Carbon Dioxide on Spore Germination in Some Clostridia
Authors: Holland Diana , Barker A. N. , Wolf J.
Published: March 2008

Summary. The rate and extent of spore germination in 3 cultures of clostridia have been investigated under controlled gas environment conditions. Germination in each of them was markedly stimulated by carbon dioxide in a variety of media. Quantitative measurements on 2 of the cultures indicated that while Clostridium bifermentans gave rapid and complete germination with as little as 3 mM bicarbonate, Cl. sporogenes PA 3679/S2 required higher concentrations for maximal response.