bluuebunny/crossref_metadata_2025 huggingface dataset:
Multicomponent velocity analysis with quaternions
Authors: Grandi A. , Mazzotti A. , Stucchi E.
Published: September 2007

Multicomponent seismic data are acquired by orthogonal geophones that record a vectorial wavefield. Since the single component recordings are not independent, the processing should be performed jointly for all the components. A way to achieve this goal is to exploit quaternions, hyper‐complex numbers that due to their very nature are apt to represent multidimensional data. In fact, quaternion algebra allows us to extend coherence functionals used for scalar observations to multicomponent data. Therefore by means of quaternions we implement semblance and other methods based on matched filtering and on the data covariance properties.

As an application we show the results from a quaternion velocity analysis carried out combining information from the geophones and from the hydrophones of an ocean bottom cable (OBC) survey, and thus recognizing the true vectorial nature of the incoming wavefield. This also allows one to relax, at least partially, vector fidelity constraints.

We demonstrate that quaternion velocity analysis yields an improved resolution with respect to the single component velocity analysis for any coherence functional chosen and that it simultaneously evidences velocity trends pertaining to different wave modes. This facilitates the interpreter in the estimation of interval Vp/Vs by means of event correlation, and in making use of a priori information from VSP and well logs. It also speeds up the velocity picking that can be performed in a single pass on a multicomponent velocity panel, rather than once for each single component velocity panel.
Evaluation of the European Heart Failure Self‐care Behaviour Scale in a United Kingdom population
Authors: Shuldham Caroline , Theaker Chris , Jaarsma Tiny , Cowie Martin R
Published: September 2007

Title.  Evaluation of the European Heart Failure Self‐care Behaviour Scale in a United Kingdom population

Aim.  This paper is a report of a study to test the internal consistency, reliability and validity of the 12‐item European Heart Failure Self‐care Behaviour Scale in an English‐speaking sample in the United Kingdom.

Background.  The European Heart Failure Self‐care Behaviour Scale quantifies the measures patients take to manage their heart failure. Produced in the Netherlands and Sweden, it has been translated into English.

Methods.  A convenience sample of 183 patients (response rate 85%) with heart failure (New York Heart Association, Class I–IV) was recruited from an outpatient clinic between July 2004 and July 2005. Mainly men (n = 143), they had a mean age of 65·6 years (sd = 12·3). They completed the Minnesota Living with Heart Failure Questionnaire, the Self‐Care of Heart Failure Index, and the European Heart Failure Self‐care Behaviour Scale during their clinic visit. The latter questionnaire was repeated at home within 2 weeks.

Results.  The scale was reliable but internal consistency was only moderate (Cronbach’s α = 0·69) and lower than in other European populations. It appears to be repeatable in the short‐term. Comparison with the Self‐Care of Heart Failure Index raised questions about whether the two questionnaires measured the same concept. Variance in self‐care was not explained by gender, age or severity of heart failure.

Conclusion.  As self‐care is an important component in the life of patients with heart failure, further exploration of the methods for measuring patients’ self‐care behaviours is warranted to enable healthcare staff to assess patients effectively. This would also help in understanding the applicability of tools in a range of patients, cultures and settings.
Maternal‐newborn nurses’ experiences of inconsistent professional breastfeeding support
Authors: Nelson Antonia M.
Published: September 2007

Title.  Maternal‐newborn nurses’ experiences of inconsistent professional breastfeeding support

Aim.  This paper is a report of a study to describe the meaning and significance of common, essential elements of inconsistent professional breastfeeding support as revealed through the experiences of maternal‐newborn nurses in a hospital.

Background.  Professional breastfeeding support has been found to have a beneficial effect on breastfeeding, although mothers also report that inconsistent professional breastfeeding support has a negative influence on their breastfeeding efforts.

Method.  An existential‐phenomenological approach was used, and interviews were conducted with 12 maternal‐newborn nurses between October 2005 and January 2006. Interview transcripts were subjected to thematic analysis.

Findings.  Inconsistency in professional breastfeeding support was directly related to the fact that ‘supporting’ breastfeeding is a dynamic, multidimensional process with relational, contextual and situational components. Eight themes were identified: Inconsistencies still exist but things are changing; A need for ‘buy in’; There is no escaping personal experience; What works for one does not work for all; Time impacts recommendations; We have a privileged vantage point; ‘My job’: what it is and what it is not and After all, breastfeeding is a maternal ‘choice’.

Conclusion.  Addressing inconsistent professional breastfeeding support involves understanding the multiple institutional and personal factors that influence this phenomenon. Because multiple practitioners assist each mother‐infant dyad in learning to breastfeed, fostering strong collaborative relationships within this support team is essential. Regular opportunities for all team members to dialogue and actively participate in the updating of breastfeeding policies may increase ‘buy in’, promote greater collaboration and decrease both conflict and inconsistencies.
Personal resilience as a strategy for surviving and thriving in the face of workplace adversity: a literature review
Authors: Jackson Debra , Firtko Angela , Edenborough Michel
Published: September 2007

Title.  Personal resilience as a strategy for surviving and thriving in the face of workplace adversity: a literature review

Aim.  This paper is a report of a literature review to explore the concept of personal resilience as a strategy for responding to workplace adversity and to identify strategies to enhance personal resilience in nurses.

Background.  Workplace adversity in nursing is associated with excessive workloads, lack of autonomy, bullying and violence and organizational issues such as restructuring, and has been associated with problems retaining nurses in the workforce. However, despite these difficulties many nurses choose to remain in nursing, and survive and even thrive despite a climate of workplace adversity.

Data sources.  The literature CINAHL, EBSCO, Medline and Pubmed databases were searched from 1996 to 2006 using the keywords ‘resilience’, ‘resilience in nursing’, and ‘workplace adversity’ together with ‘nursing’. Papers in English were included.

Findings.  Resilience is the ability of an individual to positively adjust to adversity, and can be applied to building personal strengths in nurses through strategies such as: building positive and nurturing professional relationships; maintaining positivity; developing emotional insight; achieving life balance and spirituality; and, becoming more reflective.

Conclusion.  Our findings suggest that nurses can actively participate in the development and strengthening of their own personal resilience to reduce their vulnerability to workplace adversity and thus improve the overall healthcare setting. We recommend that resilience‐building be incorporated into nursing education and that professional support should be encouraged through mentorship programmes outside nurses’ immediate working environments.
Multi‐scale features for identifying individuals in large biological databases: an application of pattern recognition technology to the marbled salamander Ambystoma opacum
Authors: Gamble Lloyd , Ravela Sai , McGarigal Kevin
Published: September 2007

Capture–mark–recapture (CMR) studies provide essential information on demography, movement and other ecological characteristics of rare and endangered species. This information is required by managers to focus conservation strategies on the most relevant threats and life stages, identify critical habitat areas, and develop benchmarks for measuring success in recovery plans. However, CMR studies have been limited by individual identification methods that are not effective or practical for many types of organisms.

We develop a pattern recognition algorithm and photo‐identification method that uses photographs taken in the field to identify individual marbled salamanders (Ambystoma opacum), using their dorsal patterns as ‘fingerprints.’ The algorithm ranks all images in a database against each other in order of visual similarity. We couple this technology with a graphic user interface to visually confirm or reject top‐ranked algorithm results. Using this process, we analyse all adult salamander captures from one year of a long‐term study.

In a database of 1008 images, the algorithm identified 95% of 101 known matches in the top 10 ranks (i.e. top 1% of all images). Time spent on manual elements of the matching process was estimated at one minute per image, permitting full indexing of all capture records.

Capture histories constructed from matched images identified 366 individuals that were captured between 2 and 5 times. Of these, less than 2% were captured at more than one of the 14 pond basins included in the study, suggesting that migrations were strongly directional to and from basins and that ‘pond‐shopping’ among first‐time breeders was infrequent. Females arrived at basins later, remained longer, and experienced more weight‐loss than males during the breeding period.

Synthesis and applications. We develop, test, and apply a pattern recognition algorithm that enables efficient identification of individual marbled salamanders in a database exceeding 1000 images. We expect that this algorithm can be modified to facilitate individual identification in many other organisms because it does not rely on manual coding or discrete geometric pattern features. High performance results suggest that it can be scaled to larger databases, allowing biologists to address critical conservation‐based questions regarding demography, reproduction and dispersal of rare and endangered species.
Hydrology, habitat change and population demography: an individual‐based model for the endangered Cape Sable seaside sparrow Ammodramus maritimus mirabilis
Authors: Elderd B. D. , Nott M. Philip
Published: September 2007

Habitat destruction and fragmentation have led to precipitous declines in a number of species of concern. For these species, traditional models that group individuals into age or stage cohorts may not accurately capture the stochasticity associated with small populations. Additionally, traditional models do not explicitly incorporate landscape‐level structure, which becomes increasingly important at small population sizes. Thus, for declining species, spatially explicit individual‐based models (SEIBM) can be used to understand both population demography and the impacts of habitat destruction, and to guide management practices to increase the chances of species survival.

To gauge the impacts of changes in habitat and also demographic rates on a US endangered species, we constructed an SEIBM for the Cape Sable seaside sparrow (Ammodramus maritimus mirabilis Howell) of the South Florida Everglades. The model simulates temporal and spatial dynamics of individual sparrows using local GIS‐based topography, vegetation and hydrology along with behavioural and demographic rates derived from field studies.

When adult mortality and, to a lesser extent, juvenile mortality were increased in model simulations, there was an increase in extinction risk and a decrease in population size, whereas changes in number of clutches or female mating range had little impact. In contrast to the effects of simulating changes in mortality rates, simulated landscape‐level changes (increasing water levels or decreasing habitat availability) were associated with dramatic population declines and increases in extinction risk. The sparrow appears to be particularly sensitive to the loss of higher‐elevation breeding habitat. These results highlight the importance of proper water‐ and land‐use management in assuring the species’ survival.

Synthesis and applications. Although changes in demographic rates affect population growth and are often the focus of conservation efforts, changes in habitat structure can also dramatically alter population viability. When both landscape‐level and demographic data are available, spatially explicit models are particularly advantageous. Not only do they allow researchers and resource managers to prioritize areas for habitat restoration and species management, but they can also be used to help focus future research efforts.
Hepatitis C virus E2 envelope protein induces dendritic cell maturation
Authors: Zhou Y. , Lukes Y. , Anderson J. , Fileta B. , Reinhardt B. , Sjogren M.
Published: September 2007

Summary.  Maturation is a critical process for dendritic cells (DC) to gain or enhance their functions in antigen presentation and T‐cell activation. In this study, we investigated the effect of hepatitis C virus (HCV) envelope protein E2 on DC maturation and related functions. We show that binding of E2 protein to DC leads to a change from immature to mature phenotype as detected by an increased expression of cell surface molecules including CD83, CD80, CD86, CD11c and MHC class II. The E2‐matured DC showed higher capacity to stimulate T‐cell proliferation and interferon‐γ production and displayed higher levels of interleukin‐12 production when compared with immature DC. The induction of DC maturation by E2 is both time‐ and dose‐dependent and can be inhibited by anti‐E2 antibodies. In addition, DC matured by E2 showed decreased uptake of bovine serum albumin and latex beads, indicating their decreased activities of endocytosis and phagocytosis upon maturation. Taken together, our results demonstrated that E2 protein is able to induce dendritic cell maturation and suggested that E2 protein may play an important role in regulation of immune responses during HCV infection.
Identification of liver fibrosis in HIV/HCV‐coinfected patients using a simple predictive model based on routine laboratory data
Authors: Berenguer J. , Bellón J. M. , Miralles P. , Álvarez E. , Sánchez‐Conde M. , Cosín J. , López J. C. , Álvarez F. , Catalán P. , Resino S.
Published: September 2007

Summary.  We constructed noninvasive models to predict significant fibrosis (F ≥ 2) and advanced fibrosis (F ≥ 3) among human immunodeficiency virus (HIV)/hepatitis C virus (HCV)‐coinfected patients, naïve for anti‐HCV treatment. A total of 296 patients with liver biopsy were randomly assigned to an estimation group (EG = 226; 70%) and a validation group (VG = 70; 30%). We developed the Hospital Gregorio Marañón (HGM)‐1 index, based on platelet count, aspartate aminotransferase (AST) and glucose, to predict F ≥ 2 and the HGM‐2 index, based on platelet count, international normalized ratio, alkaline phosphatase and AST to predict F ≥ 3. The area under the receiver operating characteristic curves (AUROCs) of the HGM‐1 index for the EG and the VG were 0.807 and 0.712 respectively. The AUROCs of the HGM‐2 index for the EG and the VG were 0.844 and 0.815 respectively. With the HGM‐1 index applied to the VG, using best cutoff scores, the negative predictive value (NPV) to exclude F ≥ 2 was 54.5% and the positive predictive value (PPV) to confirm F ≥ 2 was 93.3%. With the HGM‐2 index applied to the VG, using best cutoff scores, the NPV to exclude F ≥ 3 was 92.3, and the PPV to confirm F ≥ 3 was 64.3%. Thus, HGM‐2 accurately predicted F ≥ 3 among HIV/HCV‐coinfected patients. HGM‐1 was less accurate at predicting F ≥ 2.
Old and emerging therapies in chronic hepatitis C: an update
Authors: Deutsch M. , Hadziyannis S.J.
Published: September 2007

Summary.  The main goal of therapy in hepatitis C virus (HCV) infection is to achieve a sustained virological response currently defined as undetectable HCV‐RNA in peripheral blood determined with the most sensitive polymerase chain reaction technique 24 weeks after the end of treatment. This goal is practically equivalent with eradication of HCV infection and cure of the underlying HCV‐induced liver disease. The current standard in hepatitis C treatment consists in combination regimens of pegylated interferon‐α (Peg‐INF‐α) with Ribavirin (RBV). Such treatment schemes are quite successful in patients with HCV genotypes 2 and 3 infections achieving HCV eradication rates of 75–90%. However, they are much less effective in patients with genotypes 1 and 4 infections with eradication rates ranging between 45% and 52%. Moreover, they have several, and sometimes severe, adverse effects and contraindications, further limiting their efficacy and applicability in an appreciable number of patients with chronic HCV‐induced liver disease. Therefore, the need for improvement of existing therapies and for development of new effective, safe and tolerable drugs is a matter of great clinical relevance and importance. In this article, recent improvements in the current standard of therapy with IFN‐α and RBV in various subsets of patients with chronic hepatitis C and in the clinical development of new emerging drugs, particularly small molecules, will be reviewed and commented. The article is divided in two main parts: (i) improvements in the standard combination therapies and schemes of approved Peg‐INF‐α with RBV and expectations from new interferons, interferon inducers and alternatives to RBV; (ii) new drugs for HCV in clinical development focusing mostly on specific inhibitors of HCV and less so on other drugs including immune therapies.
Defective response to Toll‐like receptor 3 and 4 ligands by activated monocytes in chronic hepatitis C virus infection
Authors: Villacres M. C. , Literat O. , DeGiacomo M. , Du W. , Frederick T. , Kovacs A.
Published: September 2007

Summary.  Toll‐like receptors (TLR) have a critical role in innate immunity against pathogens. We investigated the cytokine response to TLR stimulation in peripheral blood cells of subjects infected with hepatitis C virus (HCV) and / or human immunodeficiency virus (HIV) in the Women Interagency HIV Study (WIHS) cohort. Interleukin (IL)‐6 in response to TLR3 and TLR4 ligands such as polyinosinic‐polycytidylic acid and lipopolysaccharide was significantly compromised in HCV‐infected women. High spontaneous secretion of IL‐6 suggested pre‐existing cell activation as a factor mediating reduced responses to TLR3 and TLR4 stimulation. To a lesser extent, tumour necrosis factor‐α and IL‐1β responses to TLR stimulation were also compromised. Monocytes, but not B cells or NK cells, were identified as the cell population spontaneously secreting cytokines and also as the cells responding to TLR stimulation. These results highlight a functional defect in antigen‐presenting cells of women with HCV infection or co‐infection. In women with existing HIV co‐infection, decreased cytokine function of antigen‐presenting cells suggests another mechanism contributing to immune dysfunction in addition to the HIV‐associated CD4 defect.
Biodiversity dynamics in isolated island communities: interaction between natural and human‐mediated processes
Authors: GILLESPIE ROSEMARY G. , CLARIDGE ELIN M. , RODERICK GEORGE K.
Published: September 2007

The flora and fauna of oceanic islands have inspired research since the early scientific explorations. Islands can be considered ‘nature's test tubes’— simple systems with multiple replicates. Our research has used the simplicity of island systems to understand ecological community dynamics and to compare the properties of island communities with those in more complex mainland systems. Here, we present three topics: (i) current patterns of biodiversity on isolated islands of the Pacific; (ii) current patterns of disturbance and invasion on islands; and (iii) future trajectories inferred from these patterns. We examine features of islands (in particular, topography and isolation) that have allowed for given levels and distribution of endemicity. The extent to which island communities are impacted by, resist or accommodate disturbance and/or invasions by nonindigenous species appears to be dictated to a large extent by properties of the native communities and how these communities were originally assembled. Accordingly, patterns of disturbance and invasion are very different for high (montane) islands that are extremely isolated compared to those that are nearer to a source of natural migrants. As with all biotas, those on islands are dynamic entities. However, the unique aspect of islands is their isolation, and extreme isolation has largely been lost over the course of the last few centuries due to the development of transportation routes. We argue that such a modified dynamic will affect the future of the biota and the processes that gave rise to the biota. Specifically for isolated habitats, ecological processes will become increasingly more likely to generate biodiversity than evolutionary processes which have been relatively more important in the past. In the short term, island biotas and other similar biotas that occur in montane habitats may fare well as species are often abundant locally in the habitat to which they are indigenous, and may demonstrate considerable resistance and resilience to invasion. However, island biotas — and other biotas that show high local endemism — will likely not fare well in the face of prolonged disturbance. The biotas in these areas generally display a relatively low dispersal capacity; therefore, under conditions of long‐term habitat modification, isolated biotas are likely to be swamped by non‐natives, which — simply because of random processes and higher propagule pressure — will move more readily into available habitats. Thus, despite the importance of incorporating the evolutionary process into conservation efforts, we must also be careful to evaluate the likely form that the processes will take when the context (specifically, extent of isolation) has been highly modified.
Peripheral Circulating Activated B‐cell Populations are Associated with Nephritis and Disease Activity in Patients with Systemic Lupus Erythematosus
Authors: Dolff S. , Wilde B. , Patschan S. , Dürig J. , Specker C. , Philipp T. , Kribben A. , Witzke O.
Published: September 2007

B‐cell‐dependent autoantibody production is a hallmark of systemic lupus erythematosus (SLE) which requires costimulatory molecules. The aim of the study was to analyse the expression of costimulatory molecules on B cells in patients with SLE. Twenty‐six patients with SLE (four male, 22 female, mean age 46 ± 15 years) as defined by the American College of Rheumatology criteria and 13 healthy controls (three male, 10 female, mean age 43 ± 15 years) were included in the study. In a subgroup analysis, SLE patients were divided according to renal involvement due to SLE (10 with and 16 patients without renal involvement). Clinical disease activity was assessed according to the systemic lupus erythematosus disease activity index (SLEDAI). Blood B‐cell populations were analysed by FACS for the cell surface marker expression of CD27, CD38, CD71, CD80, CD86 and CD137 ligand. The expression levels of CD71, CD80 and CD86 on B cells were significantly enhanced in SLE patients when compared with healthy controls (27 ± 3% versus 11 ± 2%, P = 0.0003, 55 ± 2% versus 28 ± 4%, P < 0.0001, 34 ± 3% versus 12 ± 2%, P < 0.0001). CD86 expression was significantly elevated in patients with renal involvement when compared with patients without renal disease (43 ± 6% versus 28 ± 3%, P < 0.05). There was a significant correlation between the expression levels of CD80 and CD86 on CD19+ B cells and disease activity. Moreover, prednisone dose significantly correlated with SLEDAI (r = 0.5, P = 0.02) and with the expression levels of CD86 (r = 0.47, P = 0.02). A pathological B‐cell population is associated with disease activity and renal involvement in SLE which are obviously resistant to therapy with medium doses of prednisone.
Testing the spatial significance of weed patterns in arable land using Mead’s test
Authors: HEIJTING S , VAN DER WERF W , KRUIJER W , STEIN A
Published: September 2007

There is a need in weed science for statistical tests for patchiness and spatial pattern. The objective of this study was to investigate the performance of Mead’s test for detecting patterns in synthetic data and in real weed counts made in maize, and making a first assessment of its applicability in ecological studies on weeds. In an extension to Mead’s test, made here for the first time, we merge original quadrat count data into rectangular cells of m by n quadrats. Care was taken to rule out the effect of starting point on the test result. Using the synthetic data, we demonstrate the ability of the test to detect both patchiness and homogeneity as deviations from randomness. The first deviation results in right‐sided significance, and the second in left‐sided significance of the test. Analysis of the real weed patterns demonstrated patchiness at many scales for five of the six investigated species and lack of any deviation from randomness in the sixth: Taraxacum officinale. The latter was the only wind dispersing species in the dataset. No deviation towards homogeneity was found in any of the real weed species at any scale. All patchy patterns showed anisotropy, being elongated in the direction of field traffic. As it turns out, Mead’s test is well suited to detect departures from randomness in observed weed patterns and enhances the suite of diagnostic tools that can be employed by weed ecologists.
Rhinitis, rhinosinusitis and quality of life in children
Authors: Passalacqua G. , Canonica G. W. , Baiardini I.
Published: September 2007

Quality of life (QoL) or, rather, health‐related QoL, is currently regarded as a crucial aspect of the general well‐being of patients and, in consequence, of the effects of a disease and its treatment. This is particularly true for respiratory allergy (asthma and rhinitis), which are chronic diseases and also for sinusitis (rhinosinusitis). A number of questionnaires (instruments), either generic or specific, have been developed and validated to assess the QoL in adults and children, for asthma and rhinitis, whereas there are few specific instruments for chronic rhinosinusitis. The literature provides strong evidence of the effects of allergic rhinitis, asthma and their treatments on QoL in paediatric patients, as well as in adults, whereas the number of experimental data on rhinosinusitis is limited, especially in children. Clinical trials evidenced some controversial points, mainly the weak correlation existing between QoL and traditional objective parameters. It has become clear that the QoL questionnaires measure the aspects of the disease that partially differ from the routinely evaluated parameters and that QoL should integrate, not replace, the objective measurements.
Kidney transplantation in infants and small children
Authors: Chavers Blanche , Najarian John S. , Humar Abhinav
Published: September 2007

Abstract:  Transplantation is now the preferred treatment for children with end‐stage kidney disease. But not all pediatric age groups have enjoyed the same success. The number of transplants in infants and young children has lagged behind the number in older children. One reason for this is the philosophy of some centers to maintain infants on dialysis until they reach some arbitrarily determined age, at which time they would undergo a transplant. If kidney transplantation is the therapy of choice for older children with renal failure, and equivalent results can be obtained in all age groups, why should it not be offered to these youngest patients? Our center’s philosophy for many years has been not to restrict transplant based on size or age. We have performed over 50 kidney transplants in infant recipients, and have shown equivalent results to those obtained in older children. Important factors in obtaining a successful outcome include the use of adult kidneys from a living donor, careful attention to operative and perioperative care, and performing the transplant early or in a pre‐emptive fashion. The latter allows for minimizing the negative impact of uremia on physical and neurologic development in infants.
Acute rejection episodes in pediatric renal transplant recipients with cytomegalovirus infection
Authors: Kranz Birgitta , Vester Udo , Wingen Anne‐Margret , Nadalin Silvio , Paul Andreas , Broelsch Christoph E. , Hoyer Peter F.
Published: September 2007

Abstract:  CMV infection is the most important opportunistic virus infection after renal transplantation leading to increased patient mortality, graft loss, risk for acute rejection episodes and impaired renal function. The potential impact of prophylactic anti‐viral therapy on long‐term graft outcome is relevant. The aim of this study was to evaluate the incidence of CMV infection, its risk factors and long‐term outcome in children after renal transplantation. 103 children (mean age 10.6 ± 5.3, range 1.6–22.0 yr) were monitored weekly for pp65 for the first 6–8 wk after renal transplantation, followed by a monthly monitoring for the first year. CMV infection occurred in 23/103 children (21.1%) with 10 patients (9.7%) developing CMV disease characterized by positive pp65 in the presence of organ involvement. The CMV R−/D+ and R+/D+ serostatus was significantly associated with an increased risk of CMV infection (p < 0.0001 and p = 0.009). 14/28 R−/D+ patients developed CMV infection despite prophylactic treatment with CMV hyperimmune globulin. The incidence of acute rejection episodes after or during CMV infection was significantly increased (p = 0.003) and the D+ serostatus was significantly associated with acute rejection episodes within the first year after transplantation (p = 0.006). In summary the overall incidence of CMV infection in this single center experience is 21.1%. The D+ serostatus represents a serious risk factor for both CMV infection and acute rejection episodes. In future the potential impact of different modalities of prophylactic anti‐viral therapy on the prevention of acute rejection should be considered.
Neutral theory: a historical perspective
Authors: LEIGH E. G.
Published: September 2007

To resolve a panselectionist paradox, the population geneticist Kimura invented a neutral theory, where each gene is equally likely to enter the next generation whatever its allelic type. To learn what could be explained without invoking Darwinian adaptive divergence, Hubbell devised a similar neutral theory for forest ecology, assuming each tree is equally likely to reproduce whatever its species. In both theories, some predictions worked; neither theory proved universally true.

Simple assumptions allow neutral theorists to treat many subjects still immune to more realistic theory. Ecologists exploit far fewer of these possibilities than population geneticists, focussing instead on species abundance distributions, where their predictions work best, but most closely match non‐neutral predictions.

Neutral theory cannot explain adaptive divergence or ecosystem function, which ecologists must understand. By addressing new topics and predicting changes in time, however, ecological neutral theory can provide probing null hypotheses and stimulate more realistic theory.
Effects of feeding yeast and propionibacteria to dairy cows on milk yield and components, and reproduction*
Authors: Lehloenya K. V. , Stein D. R. , Allen D. T. , Selk G. E. , Jones D. A. , Aleman M. M. , Rehberger T. G. , Mertz K. J. , Spicer L. J.
Published: September 2007

To determine the effect of supplemental feeding of Diamond V‐XP yeast (XPY) alone or in combination with propionibacteria strain P169 on milk production, milk components, body weight, days to first and second ovulation, plasma insulin, and plasma and milk glucose, 31 primiparous and multiparous (MP) Holstein cows were fed one of three dietary treatments between 2 weeks prepartum to 30 weeks postpartum: (i) control (n = 10), fed a corn silage‐based total mixed ration (TMR); (ii) XPY (n = 11), fed control TMR plus XPY (at 56 g/head/day); and (iii) P169+XPY (n = 10), received control TMR plus XPY plus P169 (at 6 × 1011 cfu/head/day). After parturition, daily milk weights were recorded, and milk samples were collected twice weekly for milk component analyses. Daily uncorrected milk, solids‐corrected milk, and 4% fat‐corrected milk production for MP cows fed P169+XPY was 9–16% greater than control MP cows, but these increases were only evident during mid lactation (9–30 weeks). The percentage of milk fat was 8–18% greater in control than XPY and P169+XPY groups. Milk lactose percentage in MP cows fed P169+XPY was 3–5% greater than in control and XPY MP cows. Primiparous and MP cows fed P169+XPY had 28–32% greater milk glucose levels than control and XPY‐fed cows. Diurnal plasma glucose concentration was not affected by diet in MP cows. Plasma insulin levels in MP cows fed P169+XPY were 30–34% greater than in other groups of MP cows. Milk glucose and plasma insulin responses to P169+XPY feeding suggest that P169+XPY might have enhanced gluconeogenesis and increased glucose uptake by the mammary gland in Holstein cows. Thus, a combined feed supplement of P169 and XPY may hold potential as a natural feed alternative to hormones and antibiotics to enhance lactational performance.
Growth, weaning performance and blood indicators of humoral immunity in Holstein calves fed supplemental flavonoids
Authors: Yaghoubi S. M. J. , Ghorbani G. R. , Rahmani H. R. , Nikkhah A.
Published: September 2007

The primary objective was to test the hypothesis that flavonoids mediate immune response and affect calf performance. Twenty Holstein calves [7 ± 2 days age; 41.4 ± 0.7 kg body weight (BW)] were randomly assigned to four treatments of (i) no; (ii) low (7.3 × 10−5 g/kg BW); (iii) medium (7.3 × 10−4 g/kg BW); and (iv) high (3.6 × 10−3 g/kg BW) doses of flavonoids intake in a completely randomized design. Calves received the treatments as a tablet until weaning or a daily intake of 680 g starter. After weaning, calves received no supplemental flavonoids and monitored until 120 days of age. The flavonoids were extracted from propolis. Treatments did not affect body length, wither height and the severity of scours. At week 5 of age, BW was higher when calves fed the high compared to the low dose of flavonoids. At week 6, calves fed the high dose of flavonoids had higher BW than those fed no or low doses of flavonoids. The serum immunoglobulin G (IgG) concentrations remained lower at the first 3 weeks of the experiment when calves received the low but not the high doses of flavonoids. At week 4, both medium and low doses of flavonoids moderated serum IgG. At week 8, the medium and high but not the low doses of flavonoids lowered serum IgG. At week 6, calves fed high and medium flavonoids doses had lower blood immunoglobulin M (IgM) than control calves. Results suggest that flavonoids affect the humoral immune response and can improve growth in young calves. This response depended on calf age. Future studies are needed to further evaluate the premise that dietary forages or the main source of flavonoids are helpful for a less stressful weaning in the modern calf raising.
Malassezia Otitis Externa in the Dog: The Effect of Heat‐fixing Otic Exudate for Cytological Analysis
Authors: Griffin J. S. , Scott D. W. , Erb H. N.
Published: September 2007

This study was conducted on 32 dogs with Malassezia otitis externa to determine the effect of heat‐fixing otic exudate on cytological analysis. Malassezia infection was confirmed by cytological examination of otic exudate. Otic discharge collected with cotton swabs was then rolled onto glass slides. One slide per dog was heat‐fixed prior to staining; the other slide was not heat‐fixed. The number of yeast in 10 oil‐immersion fields (1000× magnification) was counted for both slides from each dog. Heat‐fixing did not systematically cause either increased or decreased numbers of Malassezia on cytology of otic exudate.
Cardiovascular risk levels in general practice patients with type 2 diabetes in rural and urban areas
Authors: Wan Qing , Harris Mark F. , Powell‐Davies Gawaine , Jayasinghe Upali W. , Flack Jeff , Georgiou Andrew , Burns Joan R. , Penn Danielle L.
Published: September 2007

Objective:  To investigate the change of cardiovascular risk factor from 2000 to 2002 in general practice patients with type 2 diabetes in urban and rural areas, and the association between cardiovascular risk (both single risk factors and coronary heart disease absolute risk (CHDAR)) and rurality in three years.

Methods:  In total, 6305 patients were extracted from 16 Divisions (250 practices). Multivariate regression at Division, practice and patient levels was conducted with adjustment for age and gender.

Results:  In each of the three years, most single individual risk factors and CHDAR were high. Comparing 2002 with 2000: for urban patients in 2002 total cholesterol (OR 0.85) and low‐density lipoprotein (OR 0.81) significantly decreased, and high‐density lipoprotein (HDL) (OR 1.16) significantly increased; for rural patients in 2002 HbA1c (OR 0.85) significantly decreased and HDL (OR 1.22) significantly increased; and CHDAR significantly improved only in urban patients (OR 0.93) in 2002. In 2002 rural patients were still more likely to be overweight/obese (OR 1.16), be current smokers (OR 1.36), and have worse HDL (OR 0.84) and triglycerides (OR 1.23) than their urban counterparts.

Conclusion:  Some key individual risk factors and CHDAR did not improve in rural patients with type 2 diabetes despite a number of programs designed to provide comprehensive care to rural patients with diabetes. More emphasis is needed on supporting access to lifestyle changes (such as smoking, diet and physical activity) in rural primary health care.
Disturbed colocalization of multidrug resistance protein 2 and radixin in human cholestatic liver diseases
Authors: Kojima Hideyuki , Sakurai Shinya , Uemura Masahito , Kitamura Kensuke , Kanno Hiroki , Nakai Yoshiyuki , Fukui Hiroshi
Published: September 2007

Background and Aim:  Endocytic retrieval of multidrug resistance protein 2 (MRP2) is closely associated with cholestasis and may be attributed to the disturbed linking of MRP2 and radixin, a cross‐linker between actin filaments and membrane proteins. This study aimed to investigate the role of radixin in the altered localization of MRP2 in various human cholestatic liver diseases.

Methods:  Using immunofluorescence microscopy, we investigated the localization and expression of MRP2 and radixin in various cholestatic liver diseases, such as drug‐induced liver injury, obstructive jaundice, primary sclerosing cholangitis and autoimmune hepatitis. Changes in localization and expression were analyzed using Scion Image (software).

Results:  In the icteric drug‐induced liver injury, MRP2 was localized outside as well as inside of ZO‐1 staining, indicating endocytic retrieval from the canalicular membrane into the pericanalicular compartments of the hepatocytes. The colocalization of MRP2 and radixin observed in the controls was disturbed, and MRP2 fluorescence disappeared in the canaliculi with disrupted radixin staining. Disturbed colocalization of MRP2 and radixin as well as endocytic retrieval of MRP2 was found in the poorly drained obstructive jaundice. When drainage was good, MRP2 was exclusively colocalized with radixin. Similar findings were observed in autoimmune hepatitis and primary sclerosing cholangitis. In the controls, the immunostaining intensity curves for MRP2 and radixin were steeply elevated in the canaliculi. The intensity curves for MRP2 and radixin were broadened in the icteric drug‐induced liver injury and poorly drained obstructive jaundice, indicating endocytic retrieval into the hepatocytes. The peak fluorescence intensities for MRP2 and radixin decreased in the icteric liver.

Conclusion:  Disturbed colocalization of MRP2 and radixin was common in various cholestatic liver diseases, which may be associated with endocytic retrieval of MRP2 due to failure in anchoring MRP2 in the canalicular membrane.
Taxonomic investigation using DNA fingerprinting in Geitlerinema species (Oscillatoriales, Cyanobacteria)
Authors: Bittencourt‐Oliveira Maria do Carmo , Massola Nelson Sidnei , Hernandez‐Marine Mariona , Romo Susana , Moura Ariadne do Nascimento
Published: September 2007

The taxonomic study of 14 strains of Geitlerinema amphibium (Ag. ex Gom.) Anagnostidis and Geitlerinema unigranulatum (R.N. Singh) Komárek and Azevedo, coming from several localities was undertaken. Use was made of morphological data and molecular data were obtained by means of the DNA fingerprinting technique using highly iterated palindrome (HIP1) sequences. The employed morphological characteristics were those used for species taxonomic identification belonging to the Geitlerinema genus, namely, cell dimensions, shape of the apical cell, motility, number and localization of cyanophycin granules in the cell. The two species revealed as polymorphic were discriminated only by means of the average cellular diameters. In spite of this, minima and maxima values of the cellular diameters overlapped. It was found from molecular analysis that a high genetic diversity and the formation of two clusters consisted of G. amphibium and G. unigranulatum, plus a sole strain keeping itself isolated from the remaining. Also, these clusters were not related to the geographic location; they encompassed strains from water bodies distant from each other by as much as 3500 km, or Brazilian and Spanish strains. Molecular and morphological data support the possibility that G. unigranulatum could be considered a synonym for G. amphibium. HIP1 fingerprinting is a powerful tool for the study of genetic of cyanobacteria closely related taxa. This study points to the necessity of using other than morphological data in the taxonomic revision of cyanobacteria, as well as in the proposition of new taxons.
Impairment of hippocampal gamma (γ)‐frequency oscillations in vitro in mice overexpressing human amyloid precursor protein (APP)
Authors: Driver Joanne E. , Racca Claudia , Cunningham Mark O. , Towers Stephen K. , Davies Ceri H. , Whittington Miles A. , LeBeau Fiona E. N.
Published: September 2007

Alzheimer's disease is associated with a dramatic decline in cognitive performance including hippocampal‐dependent memory. We have investigated one feature of hippocampal activity related to memory, the γ (30–80 Hz)‐frequency rhythm. Hippocampal slices from mice overexpressing the human amyloid precursor protein (APP)SWE mutation (TAS10) were compared at 8 and 16 months of age with wild‐type littermates. In slices obtained from TAS10 mice aged 8 months the γ‐frequency activity evoked with bath application of 200 nm kainate was significantly (P < 0.05; n = 8 slices, five animals) impaired (area power, 5956 ± 2487 µV2) compared to slices from wild‐type animals (area power, 18 256 ± 7880 µV2). At 16 months of age there was no longer a significant difference (P > 0.05; n = 11 slices from five animals) between slices from TAS10 and wild‐type control mice as the wild‐type mice now exhibited a marked age‐dependent reduction in γ‐frequency activity (TAS10 area power, 5751 ± 1573 µV2; wild‐type area power = 5379 ± 1454 µV2). Although no dense‐core plaques were evident at 8 months there was detectable amyloid labelling in the TAS10 mice which might account for the deficits in γ activity observed at this age. Dense plaques were clearly evident in the TAS10, but not wild‐type, mice at 16 months of age but no further reductions in γ‐frequency activity were seen in the TAS10 mice. These data suggest that deficits in network function in Alzheimer's disease occur early and are not directly correlated to amyloid load.
Laser capture microdissection and microarray analysis of dividing neural progenitor cells from the adult rat hippocampus
Authors: Gurok Ulf , Loebbert Ralf W. , Meyer Axel H. , Mueller Reinhold , Schoemaker Hans , Gross Gerhard , Behl Berthold
Published: September 2007

Neural progenitor cells reside in the hippocampus of adult rodents and humans and generate granule neurons throughout life. Knowledge about the molecular processes regulating these neurogenic cells is fragmentary. In order to identify genes with a role in the proliferation of adult neural progenitor cells, a protocol was elaborated to enable the staining and isolation of such cells under RNA‐preserving conditions with a combination of immunohistochemistry and laser capture microdissection. We increased proliferation of neural progenitor cells by electroconvulsive treatment, one of the most effective antidepressant treatments, and isolated Ki‐67‐positive cells using this new protocol. RNA amplification viain vitrotranscription and subsequent microarray analysis revealed over 100 genes that were differentially expressed in neural progenitor cells due to electroconvulsive treatment compared to untreated control animals. Some of these genes have already been implicated in the functioning of neural progenitor cells or have been induced by electroconvulsive treatment; these include brain‐derived neurotrophic factor (Bdnf), PDZ‐binding kinase (Pbk) and abnormal spindle‐like microcephaly‐associated (Aspm). In addition, genes were identified for which no role in the proliferation of neurogenic progenitors has been described so far, such as enhancer of zeste homolog 2 (Ezh2).
Estrogen modulates neuronal movements within the developing preoptic area–anterior hypothalamus
Authors: Knoll John Gabriel , Wolfe Cory A. , Tobet Stuart A.
Published: September 2007

The preoptic area–anterior hypothalamus (POA‐AH) is characterized by sexually dimorphic features in a number of vertebrates and is a key region of the forebrain for regulating physiological responses and sexual behaviours. Using live‐cell fluorescence video microscopy with organotypic brain slices, the current study examined sex differences in the movement characteristics of neurons expressing yellow fluorescent protein (YFP) driven by the Thy‐1 promoter. Cells in slices from embryonic day 14 (E14), but not E13, mice displayed significant sex differences in their basal neuronal movement characteristics. Exposure to 10 nm estradiol‐17β (E2), but not 100 nm dihydrotestosterone, significantly altered cell movement characteristics within minutes of exposure, in a location‐specific manner. E2 treatment decreased the rate of motion of cells located in the dorsal POA‐AH but increased the frequency of movement in cells located more ventrally. These effects were consistent across age and sex. To further determine whether early‐developing sex differences in the POA‐AH depend upon gonadal steroids, we examined cell positions in mice with a disruption of the steroidogenic factor‐1 gene, in which gonads do not form. An early‐born cohort of cells were labelled with the mitotic indicator bromodeoxyuridine (BrdU) on E11. More cells were found in the POA‐AH of females than males on the day of birth (P0) regardless of gonadal status. These results support the hypothesis that estrogen partially contributes to brain sexual dimorphism through its influence on cell movements during development. Estrogen's influence may be superimposed upon a pre‐existing genetic bias.