bluuebunny/crossref_metadata_2025 huggingface dataset:
Age dependency and mutual relations in T and B lymphocyte abnormalities in common variable immunodeficiency patients
Authors: Vlková M , Thon V , Šárfyová M , Bláha L , Svobodník A , Lokaj J , Litzman J
Published: December 2005

Common variable immunodeficiency (CVID) is primary hypogammaglobulinaemia with an unknown aetiopathogenesis. Although various abnormalities of T and B cells have been described, their pathogenetic roles are unclear. We determined T and B lymphocyte subsets known to be abnormal in CVID in order to disclose possible relations between numerical abnormalities in those cells. Markers associated with B cell development (CD21, CD27, IgM, IgD) were determined on B lymphocytes (CD19+); T lymphocyte development (CD45RA, CD45RO, CD62L) and activation markers (CD25, CD27, CD28, CD29, CD38, CD57, HLA-DR) were determined on CD4+ and CD8+ T lymphocytes in 42 CVID patients and in 33 healthy controls. Abnormalities in CD4+ T lymphocyte activation markers (increase in CD29, HLA-DR, CD45RO, decrease in CD27, CD62L, CD45RA) were observed particularly in patients with a decreased number of memory (CD27+) and mature (CD21+) B cells (group Ia according to the Freiburg group’s classification), while abnormalities observed in CD8+ cells (increase in CD27 and CD28 and decrease in HLA-DR, CD57 and CD38) did not depend upon grouping patients together according to B lymphocyte developmental subpopulations. We observed correlations between immature B cells (IgM+ CD21–) and expression of CD27, CD62L, CD45RA, CD45RO and HLA-DR on CD4+ T cells in CVID patients but not in the control group. The expression of CD27 and CD45RA on CD4+ T lymphocytes, such as the percentage of IgD+ CD27– and IgD+ CD27+ cells in B lymphocytes, showed age dependency to be more significant than in the control group. Our study demonstrates that T and B lymphocyte abnormalities in CVID are partially related to each other. Some of those abnormalities are not definite, but may evolve with age of the patient.
Assessing the benefits of frugivory for seed germination: the importance of the deinhibition effect
Authors: ROBERTSON A. W. , TRASS A. , LADLEY J. J. , KELLY D.
Published: December 2005

Many studies have examined the effects of frugivores on the germination of seeds of fleshy fruited plants. However, three key issues are rarely addressed: the need to measure germination of seeds in intact fruits; the effect of germination conditions on results; and the distinction between deadvsdormant seeds.

A literature review including 51 plant species from 28 families found that the often‐measured scarification effect (germination of bird‐defecatedvshand‐cleaned seeds) is significantly smaller than the rarely‐measured deinhibition effect (germination of hand‐cleaned seedsvsthose in intact fruits).

Both the literature review and new experimental data show that germination conditions affect germination. In particular, seeds in intact fruits have much lower germination percentages in Petri dishes than in the field. Poor germination from intact fruits in Petri dishes may be an artefact.

A field experiment with three New Zealand species showed variable effects of non‐removal of the fruit pericarp. The retention of the pericarp had no effect on germination inNestegis cunninghamii; increased the proportion of seeds entering dormancy inMelicytus lanceolatus; and greatly increased seed mortality inPennantia corymbosa.

Germination experiments must be designed carefully to evaluate accurately the risks for plants of frugivory mutualism failures.
A clinicopathological study of nodal marginal zone B‐cell lymphoma. A report on 21 cases
Authors: Traverse‐Glehen A , Felman P , Callet‐Bauchu E , Gazzo S , Baseggio L , Bryon P A , Thieblemont C , Coiffier B , Salles G , Berger F
Published: December 2005

Aims : To report the clinicopathological findings of 21 cases of primary nodal marginal zone B‐cell lymphoma (NMZL). NMZL is a recently characterized lymphoma and few series have been published.

Methods and results : The clinical data were characteristic of a disseminated disease at presentation: presence of peripheral and abdominal lymph nodes, bone marrow involvement (62%), disease stage III and IV (76%), elevated lactate dehydrogenase (LDH) (48%). Other features included peripheral blood involvement (23%), anaemia (24%), thrombocytopenia (10%) and presence of serum M component (33%), while the previously reported association with hepatitis C virus and cryoglobulinaemia was not found. Relapses were frequent but the majority of patients receiving chemotherapy had a good initial response. Morphological features were heterogeneous and there were some differences compared with other marginal zone B‐cell lymphomas (MZL). Pure monocytoid B‐cell lymphomas were rare (10%) but a minor component of monocytoid B cell was observed more frequently (23%). Plasmacytoid or plasmacytic differentiation was a very common feature (61%). Large cells and a high mitotic count were also frequent (57%).

Conclusion : NMZL can be distinguished from splenic MZL and extranodal MZL by its aggressive morphology and disseminated disease at presentation.
Prevalence of hepatitis C virus infection in cases of B‐cell lymphoma in Japan
Authors: Takeshita M , Sakai H , Okamura S , Higaki K , Oshiro Y , Uike N , Yamamoto I , Shimamatsu K , Muranaka T
Published: December 2005

Aims : To determine the prevalence of hepatitis C virus (HCV) infection in B‐cell lymphoma in Japan. HCV infection and type II (monoclonal IgM) cryoglobulinaemia (CG) may be involved in the pathogenesis of low‐grade B‐cell lymphoma (ML) in southern Europe.

Methods and results : Forty‐five (11.3%) of 400 B‐cell ML cases were HCV antibody (Ab) positive, which was significantly (P < 0.01) higher than the blood donors (2.5%). Among them, 28 diffuse large B‐cell lymphoma (DLBCL) cases were included. In the primary sites, 10 (47.6%) of 21 splenic DLBCL and seven (23.3%) of 30 gastric DLBCL were HCV Ab positive, which were significantly (P < 0.05) higher than the myeloma cases (4.9%). HCV infection was rarely (4.2%) detected in 24 lymphoplasmacytic and salivary gland low‐grade B‐cell ML cases. Type II CG was detected in one myeloma case (3.5%) of 29 HCV+ B‐cell ML. By real‐time polymerase chain reaction, HCV RNA was detected in fresh tumour tissues of all 11 B‐cell ML cases examined. Lymphoma cells were positive for the envelope HCV non‐structural (NS)3 and envelope (E2) proteins in six of eight examined B‐cell ML cases.

Conclusions : The rare incidence of type II CG is characteristic of Japanese HCV+ ML patients and may influence the low incidence of low‐grade B‐cell ML. HCV infection may play a role in lymphomagenesis of splenic and gastric DLBCL.
Persistent nodules at injection sites (aluminium granuloma)—clinicopathological study of 14 cases with a diverse range of histological reaction patterns
Authors: Chong H , Brady K , Metze D , Calonje E
Published: December 2005

Aims : To assess and document the spectrum of histological appearances of persistent swellings which occur at injection sites following vaccination or allergen desensitization.

Methods and results : Fourteen cases were studied. Four overlapping histological reaction patterns were evident. Ten cases showed at least focal fibrosis, fat necrosis and a mixed inflammatory cell infiltrate mainly in the subcutis, giving rise to the features of a non‐specific septal and lobular panniculitis. The appearance of three cases, in addition to the non‐specific panniculitis pattern, also included prominent lymphoid follicles with germinal centres and a prominent perifollicular infiltrate resembling a lymphoma (pseudolymphoma pattern). A single case mimicked lupus profundus, with a perivascular and periadnexal infiltrate in the dermis and hyaline fat necrosis. Three cases showed a predominantly palisaded histiocytic infiltrate surrounding eosinophilic necrobiosis, in a pattern closely resembling deep granuloma annulare or rheumatoid nodule. The remaining case partly showed this appearance, but in combination with panniculitis, thus demonstrating an overlap of patterns. A common feature in all 14 cases was the focal presence of histiocytes with abundant violaceous granular cytoplasm. These were shown to contain aluminium on energy dispersive X‐ray microanalysis.

Conclusion : Persistent swellings at injections sites show a variety of overlapping patterns, which mimic other conditions. Identification of characteristic histiocytes with violaceous granular cytoplasm is the key distinctive feature allowing the correct diagnosis to be reached.
Cytosolic overexpression of p62 sequestosome 1 in neoplastic prostate tissue
Authors: Kitamura H , Torigoe T , Asanuma H , Hisasue S‐I , Suzuki K , Tsukamoto T , Satoh M , Sato N
Published: December 2005

Aims : To investigate the expression of p62 in various prostatic tissues, and to demonstrate different immunohistochemical patterns of p62 expression in distinct pathological entities of the prostate. The p62 sequestosome 1 (SQSTM1) gene product is a multifunctional protein with ubiquitous expression in normal adult tissue.

Methods and results : Overexpression of p62 was detected in prostate cancer cell lines and tissues by reverse transcriptase‐polymerase chain reaction. Immunohistochemical staining for p62 was performed on 73 cases of paraffin‐embedded prostatic tissue. p62 was negative or weakly positive only in the nucleus (pattern N) of prostatic gland epithelium in nine normal and hyperplastic prostate specimens, whilst most cancerous tissue showed intense, uniform staining for p62 in the cytoplasm (pattern C). Of the prostate cancer specimens, 91% showed positive pattern C immunoreactivity. Of the cases with high‐grade prostatic intraepithelial neoplasia (PIN) around cancer, 77% showed pattern C. However, in specimens from the patients without prostate cancer PIN displayed pattern C in only 32% of cases. Western blot analysis showed that all cancer cell lines expressed p62 in the cytoplasm but there was little nuclear expression.

Conclusion : Cytosolic overexpression of p62 is a novel immunohistochemical characteristic in prostatic adenocarcinoma and high‐grade PIN, suggesting that p62 might be a novel marker for prostatic malignancy.
Influence of obesity on timing of puberty
Authors: BIRO FRANK M. , KHOURY PHILIP , MORRISON JOHN A.
Published: December 2005

Timing of normal pubertal maturation has received increased attention over the past several years. Age of menarche showed a dramatic decrease in the first half of the 20th century in Western nations; since 1960, the decrease in age of menarche has slowed and, in some societies, has actually increased. More recently, age of onset of pubertal maturation appears to have decreased, especially in girls. Multiple studies have demonstrated that childhood levels of obesity and ponderosity are associated with earlier menarche in girls. Earlier maturation in boys, however, is associated with lower adiposity and ponderosity. Secular changes in the United States as well as around the world have noted increases in prevalence as well as extent of overweight. Factors contributing to these changes include increases in calories and fast food consumption, decreases in physical activity, and increases in television viewing. There appear to have been selective advantages to lower metabolic rate (the ‘thrifty’ gene hypothesis), and earlier maturation. However, changes in caloric consumption, caloric density and physical activity, combined with greater lifespan, may allow expression of the adverse consequences of these adaptations, such as the metabolic syndrome or cancers.
The roe deer as a model for studying seasonal regulation of testis function
Authors: KLONISCH THOMAS , SCHÖN JENNIFER , HOMBACH‐KLONISCH SABINE , BLOTTNER STEFFEN
Published: December 2005

In mature male seasonal breeders, the circannual cycles of testicular growth and involution involve significant changes in structure and function of both the tubular and interstitial testicular compartment. Roe deer (Capreolus capreolus) are seasonal breeders with a short defined rutting season from mid‐July to mid‐August and represent a unique non‐rodent model for studying testicular functions during the course of a complete reproductive cycle with naturally changing photoperiod. Germ cells and Sertoli cells of the seminiferous tubules and the interstitial Leydig cells all display significant morphological and physiological alterations during the seasonal changes. In contrast to the germ cell population, Sertoli and Leydig cells persist as a numerically constant cell population in the roe deer testis. This report emphasizes the intricate relationship between seasonal cellular differentiation, intratesticular growth factor networks and their impact on the functional dynamics during the seasonal changes in roe deer testis.
Trends in testicular cancer incidence in the Nordic countries, focusing on the recent decrease in Denmark
Authors: JACOBSEN RUNE , MØLLER HENRIK , THORESEN STEINAR Ø. , PUKKALA EERO , KJÆR SUSANNE KRÜGER , JOHANSEN CHRISTOFFER
Published: December 2005

Testicular cancer is the most frequent malignancy among young men, and there have been steady increases in its incidence in most western countries for many decades. Recently, a decrease was seen in some countries, including Denmark. Here, we report recent trends in testicular cancer incidence in the Nordic countries. We address the hypothesis that the causal factors for testicular cancer in Denmark are related to birth cohort and that non‐seminoma and seminoma tumours have a common aetiology. An overall increase in testicular cancer incidence was found in the Nordic countries, corresponding to increases with each consecutive birth cohort in each country. In Denmark, a decline in incidence was observed during the past 5 years, and men born around 1943 and around 1968 showed lower incidences than men born just before or just after these dates. These birth‐cohort effects were seen both for seminoma and non‐seminoma tumours. This descriptive study confirms the hypothesis that birth cohort has a major influence on the incidence pattern of testicular tumours and suggests that seminoma and non‐seminoma have common aetiological factors.
Seminal tissue factor revisited
Authors: LWALEED B. , JACKSON C. , GREENFIELD R. , STEWART A. , DELVES G. , BIRCH B. , COOPER A.
Published: December 2005

Studies of seminal tissue factor (TF) are few and mostly based on small numbers. Due to the reported lack of factor (F) X in semen, it has been suggested that TF may not have a role in seminal coagulum formation. However, recent identification of a number of haemostatic factors in semen justifies a re‐evaluation of its occurrence. Semen specimens were collected from sub‐fertile (n = 19), normally fertile (n = 33), semen donors (n = 30) and vasectomized subjects (n = 62), some fractionated into sperm, a prostasome‐rich fraction and seminal plasma. Functional and antigenic TF levels were measured and related to conventional fertility parameters. Semen contains high concentration of functional and antigenic TF. Most TF was found in seminal plasma prepared by low‐speed centrifugation. When further fractionated by ultracentrifugation much of this may reside in the pellet (prostasomal fraction). It was also detectable on sperm. TF antigen levels were higher in vasectomized subjects than sub‐fertile, normally fertile, donor (p = 0.02) and a ‘pooled normal semen parameters’ (PNSP) stratification (derived from a combination of measurements) (p = 0.06). The sub‐fertile group showed a wider variation than normal, donor or the PNSP subjects. Seminal TF antigen levels correlated significantly with sperm agglutination (p = 0.03) and abnormal sperm morphology (p = 0.04). Subjects with anti‐sperm antibodies also showed high TF antigen levels. In conclusion, semen contains functional and antigenic TF at high concentrations. A full complement of clotting factors probably exists in semen, so some pro‐coagulant role for TF should not be excluded. Decreased seminal TF levels appear to be associated with seminal parameters that are known to favour male fertility.
In utero exposure to persistent organic pollutants in relation to testicular cancer risk
Authors: HARDELL LENNART , VAN BAVEL BERT , LINDSTRÖM GUNILLA , ERIKSSON MIKAEL , CARLBERG MICHAEL
Published: December 2005

Testicular cancer is the most common tumour type in young men. In Sweden the annual age‐adjusted incidence increased significantly by 2.4% during the time period 1984–1993 and during 1994–2003 by 1.4%. Exposure to endocrine disrupting chemicals during the foetal period has been postulated to be a risk factor. In this investigation we studied the concentrations of chlorinated biphenyls (PCBs), p,p′‐dichlorodiphenyl‐dichloroethylene (pp′‐DDE), hexachlorobenzene (HCB), chlordanes and polybrominated diphenylethers (PBDEs) in 58 cases with testicular cancer and 61 age‐matched controls. Furthermore, case and control mothers were also asked to participate and 44 case mothers and 45 control mothers agreed. No significant differences were found between cases and controls. Case mothers had in general higher concentrations of these chemicals. For the sum of PCBs an odds ratio (OR) = 3.8, 95% confidence interval (CI) = 1.4–10 was calculated using the median concentration for the controls as cut‐off value. For HCB OR = 4.4, CI = 1.7–12 and for PBDE OR = 2.5, 95% CI = 1.02–6.0 were obtained, whereas OR was not significantly increased for pp′‐DDE and sum of chlordanes. The cases were born during a period with high concentrations of persistent organic pollutants (POPs) in humans. The decline of the increasing incidence of testicular cancer during recent years may reflect decreasing body burden of certain POPs since the 1980s.
A spatially explicit approach to estimating species occupancy and spatial correlation
Authors: HUI CANG , McGEOCH MELODIE A. , WARREN MARIÉ
Published: December 2005

Understanding and predicting the form of species distributions, or occupancy patterns, is fundamental to macroecology and is dependent on the identification of scaling relationships that underlie the patterns observed.

Occupancy–abundance models based on the negative binomial distribution and Taylor's power law are spatially implicit, rather than explicit, as they include no information on the relative positions of individuals. Here we present a spatially explicit model, the spatial scaling occupancy (SSO) model, to estimate species occupancy and spatial correlation, based on join‐count statistics, or a pair approximation, approach. This model provides a spatially explicit description of species range size and aspects of range structure.

Occupancy data from Drosophilidae species inhabiting a decaying fruit mesocosm were used to test the SSO model. Predictions from the spatially implicit and explicit models were largely equally accurate. The SSO model is thus more efficient as it is less data demanding, and more informative as it provides an estimation of spatial correlation.

The results also showed that species distribution patterns differ when examined with spatially implicit vs. explicit approaches; the scaling relationship between occupancy and local density identifies a focal grain for studying the scale‐dependent nature of ecological relationships; and the longer the length of the sample edge, the higher the occupancy observed under conditions of spatial aggregation.

The SSO model presents a step towards a general scaling model for occupancy, and demonstrates that the inclusion of spatially explicit information in macroecological models warrants further attention.
Intraguild indirect effects through trophic cascades between stream‐dwelling fishes
Authors: KATANO OSAMU , NAKAMURA TOMOYUKI , YAMAMOTO SHOICHIRO
Published: December 2005

To examine the strength and role of indirect effects through trophic cascades by omnivorous fish on algal biomass in streams, we introduced one of four fish species (ayuPlecoglossus altivelis altivelis, pike gudgeonPseudogobio esocinus esocinus, Japanese daceTribolodon hakonensisand pale chubZacco platypus) in experimental pools. We also investigated the indirect effects of gudgeon, dace and chub on the growth of ayu.

We chose the four fish species across a continuum of omnivory. Ayu fed mainly on benthic algae, and gudgeon predominantly on invertebrates. Dace and chub fed on both algae and invertebrates, but dace preyed on invertebrates more than chub.

The presence of gudgeon, dace and chub reduced the number of algal‐feeding invertebrates and increased the algal biomass through trophic cascades. Consequently, ayu growth rate over the experimental period in pools with one of the three fish species was 25·9–44·1 times greater than the growth rate in pools with only ayu.

The positive indirect effect on ayu growth was large for gudgeon and dace and small for chub, whereas the addition of ayu reduced ayu growth considerably due to intraspecific competition.

The relative intensity of indirect effects on ayu growth through trophic cascades was predictable from the food overlap between ayu and the other fishes. However, the similar strength of indirect effects by gudgeon and dace that fed differently on algae and invertebrates suggests that feeding behaviour, prey preference and trait‐mediated indirect interactions were also important in the prediction.
Hunt warm, rest cool: bioenergetic strategy underlying diel vertical migration of a benthic shark
Authors: SIMS DAVID W. , WEARMOUTH VICTORIA J. , SOUTHALL EMILY J. , HILL JACQUELINE M. , MOORE PIPPA , RAWLINSON KATE , HUTCHINSON NEIL , BUDD GEORGINA C. , RIGHTON DAVID , METCALFE JULIAN D. , NASH JON P. , MORRITT DAVID
Published: December 2005

Diel vertical migration (DVM) is a widespread phenomenon among marine and freshwater organisms and many studies with various taxa have sought to understand its adaptive significance. Among crustacean zooplankton and juveniles of some fish species DVM is accepted widely as an antipredator behaviour, but little is known about its adaptive value for relatively large‐bodied, adult predatory fish such as sharks. Moreover, the majority of studies have focused on pelagic forms, which raises the question of whether DVM occurs in bottom‐living predators.

To investigate DVM in benthic predatory fish in the marine environment and to determine why it might occur we tracked movements of adult male dogfish (Scyliorhinus canicula) by short‐ and long‐term acoustic and archival telemetry. Movement studies were complemented with measurements of prey abundance and availability and thermal habitat within home ranges. A thermal choice experiment and energy budget modelling was used to investigate trade‐offs between foraging and thermal habitat selection.

Male dogfish undertook normal DVM (nocturnal ascent) within relatively small home ranges (∼100 × 100 m) comprising along‐bottom movements up submarine slopes from deeper, colder waters occupied during the day into warmer, shallow prey‐rich areas above the thermocline at night. Few daytime vertical movements occurred. Levels of activity were higher during the night above the thermocline compared to below it during the day indicating they foraged in warm water and rested in colder depths.

A thermal choice experiment using environmentally realistic temperatures supported the field observation that dogfish positively avoided warmer water even when it was associated with greater food availability. Males in laboratory aquaria moved into warm water from a cooler refuge only to obtain food, and after food consumption they preferred to rest and digest in cooler water.

Modelling of energy budgets under different realistic thermal‐choice scenarios indicated dogfish adopting a ‘hunt warm − rest cool’ strategy could lower daily energy costs by just over 4%. Our results provide the first clear evidence that are consistent with the hypothesis that a benthic marine‐fish predator utilizes DVM as an energy conservation strategy that increases bioenergetic efficiency.
Density‐dependent body growth reduces the potential of marine reserves to enhance yields
Authors: GÅRDMARK ANNA , JONZÉN NICLAS , MANGEL MARC
Published: December 2005

Some models of marine no‐take reserves predict that reserves can enhance fishery yield. However, empirical evidence of this remains inconclusive. One reason for this may be the disregard for density‐dependent body growth in most models. Density‐dependent body growth links the number and size of individuals, and thus could influence the biomass of fishery yield.

We developed an age‐ and size‐structured model of an exploited population and analysed the effect of implementing a no‐take reserve of varying size.

Protecting part of a population from exploitation in a no‐take reserve results in a rapid build‐up of biomass inside the reserve because of increased survival. However, when body growth is density‐dependent it also results in reduced length at a given age within the no‐take reserve because of crowding effects. This prediction is backed up by empirical observations.

If there is export of individuals (here larvae) from the no‐take reserve, length at a given age will also decrease in the fished part of the population outside the reserve. An increase in the number of exploitable individuals thus results in decreased individual body mass. The positive effect of larval drift on fished population size and catch numbers will therefore rarely translate into an increase in equilibrium yield biomass.

Synthesis and applications. When body growth is density‐dependent, implementation of no‐take reserves affects the body size of both protected and exploitable individuals. Although reserves can have several benefits besides increasing yields, our study shows that, if density‐dependent somatic effects are important, a general increase in yield biomass cannot be expected. In populations with density‐dependent body growth, reserves are more likely to decrease yield biomass unless the population is severely overexploited. Analyses of the efficiency of marine reserves as a means of enhancing the yield of fisheries need to account for ecological processes, and density‐dependent body growth is likely to be key.
Pollen dispersal of oilseed rape: estimation of the dispersal function and effects of field dimension
Authors: KLEIN ETIENNE K. , LAVIGNE CLAIRE , PICAULT HERVE , RENARD MICHEL , GOUYON PIERRE‐HENRI
Published: December 2005

Debate continues regarding the ecological impacts of genetically modified (GM) crops and their coexistence with non‐GM crops in Europe. In this debate, quantitative predictions of gene dispersal by pollen are necessary, and as a result numerous plot‐to‐plot gene flow experiments have been performed with various crops. However, plot‐to‐plot cross‐pollination rates (CPR) depend on spatial configuration of plots, implying that (i) they are difficult to compare among experiments and (ii) functions directly fitted on CPR data are inappropriate for predictions in other spatial contexts.

Modelling pollen dispersal via an individual dispersal function (IDF) circumvents these problems by accounting for spatial designs. We detail for oilseed rape how this approach can be used to both estimate an IDF from field data and predict CPR between two neighbouring fields of various sizes and shapes. Predictions were used to investigate the sensitivity of CPR to the family of IDF, the uncertainty in parameter estimates and the effects of field dimensions and isolation distances.

We fitted a range of families of IDF, including several types of tails, on previously published data. The best IDF was a fat‐tailed power‐law function, meaning frequent long‐distance dispersal.

The choice of IDF appeared crucial when predicting CPR between fields, occasionally being even more important than the distance between fields. Width of the source field and depth of the recipient field were next in importance. When approximated CPR were calculated without considering field dimensions, using distance between field centres gave better performance than field margins.

Synthesis and applications. This study demonstrates the value of IDF for quantitative predictions of pollen flow in variable spatial configurations. A spatially explicit model of agro‐ecosystems used to define management rules for the commercial release of GM crops in Europe already employs IDF but underestimates long‐distance dispersal for oilseed rape. These new parameter estimates will refine the performance of these models. Moreover, the detailed guidelines for estimating an IDF should encourage such statistical analysis of other dispersal data, enabling comparisons of dispersal data obtained for different environments and species and providing new IDF for management models.
Soil carbon addition affects plant growth in a species‐specific way
Authors: ESCHEN RENÉ , MÜLLER‐SCHÄRER HEINZ , SCHAFFNER URS
Published: December 2005

Restoration of ex‐arable land to species‐rich habitats has become common practice in Europe as a result of Agri‐Environment Regulations. The results, however, are highly variable and often disappointing. Competition from weedy species as a result of high soil inorganic nitrogen levels can negatively affect the establishment and growth of desirable grassland plant species. One method that has been put forward to alter competitive interactions among plant species on restoration sites is the addition of carbon (C) to the soil. To make C addition a tool for successful restoration of species rich grassland, it should affect plant growth in a species‐specific way.

We present results of a greenhouse study to assess the species‐specific responses of 29 plant species to a range of C volumes added to the soil. Specifically, we tested whether functional group affiliation (legumes, other forbs and grasses), life form (annual and perennial) or nitrophilic status could explain parts of the variation in the response of the selected plant species to C addition.

Amending soil with increasing levels of C resulted in a log‐linear reduction in biomass accumulation of all plant species tested, but the responses varied significantly between the plant species. Functional group and life form explained a significant amount of variation observed among the plant species tested. The response of legumes to C addition was less pronounced than that of other forbs and grasses. Grasses showed a decrease in shoot : root ratio in response to C addition, while the shoot : root ratio of legumes and forbs remained constant. A greater shoot biomass reduction in response to C addition was found for annual species than for perennial species.

No correlation was found between the slope of the regression of log biomass vs. the amount of C added and the Ellenberg N‐values, indicating that there is no simple relationship between the nitrophilic status of a plant species and its response to C addition.

Synthesis and applications. The results suggest that adding C to soil is a promising tool in grassland restoration. C addition disproportionately reduced above‐ground biomass accumulation by annual plant species and grasses, which often dominate early succession on ex‐arable land. This may facilitate the establishment and growth of late‐seral species and thus the restoration of species‐rich grassland on ex‐arable land.
Estimating species richness: calibrating a large avian monitoring programme
Authors: KÉRY MARC , SCHMID HANS
Published: December 2005

Species richness is the most widely used measure for the diversity of a biological community. Unfortunately, the number of species counted is usually a biased measure, as not all species present may be detected. Use of species counts as a proxy for true species richness requires the assumption of constant (over space and time) species detectability. This index assumption is hardly ever tested and, if violated, comparisons over time, space or other dimensions, for example different habitats, will be distorted. In monitoring programmes one therefore needs to know the proportion of species present that are detected and how this proportion is affected by external factors.

We used capture–recapture techniques to calibrate the Swiss breeding bird survey, where species richness is recorded annually in c. 270 1‐km2 quadrats during two to three visits and interest is focused on annual trends and regional comparisons. Hitherto, analysis has been restricted to species counts, while species detectability and its determinants are not known. We used the interpolated jackknife estimator to compute mean species detectability for 268 quadrats in 2001–03 and tested determinants of detectability related to space, time, observer, survey effort and biology.

Mean species detectability averaged 0·89 (SD 0·06, range 0·72–1·00), with no significant difference among years and significant, but small, regional differences. Observers differed, but surprisingly not in relation to their experience in a quadrat. Detectability was positively related to mean visit duration. Larger communities had a lower mean species detectability. A slight violation of population closure because of staggered arrival of migrants did not introduce any measurable bias into our results.

Synthesis and applications. Species detectability in the Swiss programme was high and varied little in relation to recognized sources of heterogeneity. Nevertheless, increased standardization should be considered for mean visit duration. While these results are pleasing for the Swiss programme and show that using counts as indices of species diversity need not always induce serious bias, conditions in other programmes, and in the future in the Swiss programme, may be quite different. Both in monitoring programmes and in ecological studies, as a way of risk minimization, species richness ought to be rigorously estimated whenever possible to avoid detection of spurious effects because of changes in species detectability.
Modelling distribution and abundance with presence‐only data
Authors: PEARCE JENNIE L. , BOYCE MARK S.
Published: December 2005

Presence‐only data, for which there is no information on locations where the species is absent, are common in both animal and plant studies. In many situations, these may be the only data available on a species. We need effective ways to use these data to explore species distribution or species use of habitat.

Many analytical approaches have been used to model presence‐only data, some inappropriately. We provide a synthesis and critique of statistical methods currently in use to both estimate and evaluate these models, and discuss the critical importance of study design in models where only presence can be identified

Profile or envelope methods exist to characterize environmental covariates that describe the locations where organisms are found. Predictions from profile approaches are generally coarse, but may be useful when species records, environmental predictors and biological understanding are scarce.

Alternatively, one can build models to contrast environmental attributes associated with known locations with a sample of random landscape locations, termed either ‘pseudo‐absences’ or ‘available’. Great care needs to be taken when selecting random landscape locations, because the way in which they are selected determines the modelling techniques that can be applied.

Regression‐based models can provide predictions of the relative likelihood of occurrence, and in some situations predictions of the probability of occurrence. The logistic model is frequently applied, but can rarely be used directly to estimate these models; instead, case–control or logistic discrimination should be used depending on the sample design.

Cross‐validation can be used to evaluate model performance and to assess how effectively the model reflects a quantity proportional to the probability of occurrence. However, more research is needed to develop a single measure or statistic that summarizes model performance for presence‐only data.

Synthesis and applications.A number of statistical procedures are available to explore patterns in presence‐only data; the choice among them depends on the quality of the presence‐only data. Presence‐only records can provide insight into the vulnerability, historical distribution and conservation status of species. Models developed using these data can inform management. Our caveat is that researchers must be mindful of study design and the biases inherent in presence data, and be cautious in the interpretation of model predictions.
Efficacy of a radar‐activated on‐demand system for deterring waterfowl from oil sands tailings ponds
Authors: RONCONI ROBERT A. , CASSADY ST. CLAIR COLLEEN
Published: December 2005

Oil sands mining is one of several industrial activities that produces effluent that is dangerous to waterfowl. Such industries require effective systems to deter birds, but current deterrents are not always successful, presumably because wildlife ignore or habituate to them.

We tested a new radar‐activated on‐demand system of deterrence in the oil sands region of Alberta, Canada, by comparing the proportion of birds that landed on a tailings pond while it was activated with the proportion that landed during two other treatments: a continuous, randomly activated, deterrent system, and control periods with no deterrents. We also assessed the efficacy of different stimuli types within the on‐demand system.

Across several bird guilds, only the on‐demand deterrent system significantly reduced the probability of birds landing in comparison with the control treatment. In addition to treatment effects, birds were more likely to land earlier in the spring and when they flew at lower altitudes, and shorebirds were more likely to land than ducks, geese and gulls.

The comparison of stimuli revealed that cannons elicited significantly more response by birds in flight than mechanized peregrine falcon effigies with speakers broadcasting peregrine sounds.

Synthesis and applications. Our results promote the use of on‐demand systems for waterfowl deterrence at tailings ponds and recommend cannons over effigies as stimuli. We suggest that oil sands deterrence efforts should (i) be operational in the early spring, when tailings ponds appear to be most attractive to migrating waterfowl, (ii) target low‐flying waterfowl and shorebirds and (iii) be effective during both day and night. These results and recommendations have potential application for problems of bird deterrence at several other industrial sites.
Statistical methods for analysing responses of wildlife to human disturbance
Authors: PREISLER HAIGANOUSH K. , AGER ALAN A. , WISDOM MICHAEL J.
Published: December 2005

Off‐road recreation is increasing rapidly in many areas of the world, and effects on wildlife can be highly detrimental. Consequently, we have developed methods for studying wildlife responses to off‐road recreation with the use of new technologies that allow frequent and accurate monitoring of human–wildlife interactions. To illustrate these methods, we studied the response of Rocky Mountain elk Cervus elaphus L. to all‐terrain vehicles (ATVs), one of the most prominent forms of summer recreation in North America. We studied elk because the species is not only of keen economic and social interest across North America and Europe but also exemplifies species that can be sensitive to human disturbance.

The study was part of a controlled landscape experiment where global positioning system (GPS)‐equipped recreationists traversed an established 32‐km route inside a 1453‐ha elk‐proof enclosure. Elk locations before and during the human disturbances were monitored using an automated telemetry system. The unique data set and study objectives led to our development of statistical methods for analysing the response of wildlife to human disturbance.

We developed a statistical method, referred to as a probabilistic flight response, which accounted for daily circadian rhythms in movement behaviour of elk, and related the probability of flight to distance to the disturbance and a number of environmental covariates. We also present methods for estimating spatially and temporally explicit movement vectors as a way of detecting and visualizing landscape‐level movement patterns.

Using these methods, we observed that elk appeared to respond at relatively long distances (> 1000 m) to ATVs, and that the estimated probability of flight appeared to be higher when elk were closer to the ATV routes, even when the distance to an ATV was large.

Synthesis and applications. Our study quantifies the response of wildlife to human disturbance at a resolution well beyond previous work, and provides methods to improve our understanding of wildlife–human interactions related to management of wildlife and recreation. These methods may be used for any study involving accurate, frequent monitoring of animals and humans with the use of GPS or similar technologies now commonly available.
Invasibility and species richness of island endemic arthropods: a general model of endemic vs. exotic species
Authors: Borges Paulo A. V. , Lobo Jorge M. , de Azevedo Eduardo B. , Gaspar Clara S. , Melo Catarina , Nunes Luis V.
Published: December 2005

Aim This paper has two objectives. First, we examine how a variety of biotic, abiotic and anthropogenic factors influence the endemic and introduced arthropod richness on an oceanic island. Second, we look at the relationship between the endemic and introduced arthropod richness, to ask whether areas with high levels of endemic species richness deter invasions.

Location The work was carried out on a young volcanic island, Terceira, in the Azores.

Methods We used standard techniques to collect data on arthropod species richness. Environmental data were obtained from the CIELO climatic model and using GIS. The explanatory value of environmental variables on a small‐scale gradient of endemic and exotic arthropod species richness was examined with generalized linear models (GLMs). In addition, the impact of both endemic and exotic species richness in the communities was assessed by entering them after the environmental variable(s) to see if they contributed significantly to the final model (the hierarchical method).

Results Abiotic (climatic and geomorphological) variables gave a better explanation of the variation in endemic species richness, whereas anthropogenic variables explained most of the variation in introduced species richness. Furthermore, after accounting for all environmental variables, part of the unexplained variance in the endemic species richness is explained by the introduced species richness and vice‐versa. That is, areas with high levels of endemic species richness had many introduced species. There is evidence of a somewhat inverse spatial distribution between a group of oceanic‐type, forest‐dwelling, endemic, relict arthropods and a group of more generalist endemic arthropods that are able to survive in disturbed marginal sites particularly rich in non‐indigenous species.

Main conclusions Richness of endemic species is mainly driven by abiotic factors such as a climatic axis (oceanic‐type localities with lower temperatures and summer precipitations) and a binary variable CALD (location of sites in caldeiras or ravines), whereas richness of introduced species depends on disturbance related factors. However, after factoring out these major influences, there is a correlation between endemic and introduced richness, suggesting that – independent of the environmental and geographical factors that affect the distribution of endemic or introduced species – the richest endemic assemblages are more prone to invasion, due probably to a facilitation process. Inconclusive evidence suggests that non‐indigenous species are limited to those sites under anthropogenic influence located mainly near forest edges, but the rate of expansion of those species to high‐altitude, core pristine sites has still to be tested.
People withMECP2mutation‐positive Rett disorder who converse
Authors: Kerr A. M. , Archer H. L. , Evans J. C. , Prescott R. J. , Gibbon F.
Published: December 2005

Background People with useful speech after regression constitute a distinct group of those with mutation‐positive Rett disorder, 6% (20/331) reported among mutation‐positive people in the British Survey. We aimed to determine the physical, mental and genetic characteristics of this group and to gain insight into their experience of Rett syndrome.

Methods Clinical and molecular data for people with Rett, aged 10 or more years at follow‐up (the study group,n = 13), with the ability to converse and aMECP2mutation are presented. They were compared with an age‐matched control group (n = 110), who could not converse and had a pathogenicMECP2mutation.

Results The study group differed significantly from the control group with regard to their disease severity (P < 0.001); feeding difficulty scores (P < 0.001); health scores (P < 0.001); epilepsy (P < 0.001); head circumference (P < 0.004); age at onset of the regression period (P < 0.001) (six in the study group did not regress) and mutation frequency (C‐terminal deletionsP = 0.014, R133CP < 0.006). The results indicate that favourable skewing of X‐inactivation is only present in a small proportion of mild cases. Speech was fragmented with a soft, breathless quality, and all but two had obviously irregular breathing. One person with an R168X mutation preferred signing to speech. All enjoyed interpersonal contact, showing affection and preferring people to objects, clearly distinguishing the condition from autism. Most were habitually anxious. Music was a source of pleasure and relaxation also providing a valuable educational asset. Even in these most able cases, understanding was severely restricted in most and little initiative was shown.

Conclusions While the Rett profile is present in these people they are commonly not classic, and the presence of speech, good head growth and lack of regression may lead to missed diagnoses. A strong association was demonstrated between this milder form of the disease and R133C and C‐terminal deletions.
Progesterone Treatment of Adult Male Rats Suppresses Arginine Vasopressin Expression in the Bed Nucleus of the Stria Terminalis and the Centromedial Amygdala
Authors: Auger C. J. , Vanzo R. J.
Published: December 2005

The steroid sensitive vasopressin cells of the bed nucleus of the stria terminalis (BST) and centromedial amygdala (CMA) are involved in numerous behavioural and physiological functions. These cells are known to be greatly influenced by gonadal steroids. Castration reduces and testosterone replacement restores arginine vasopressin (AVP)‐immunoreactive (‐ir) labelling and AVP mRNA expression in the BST and CMA. Gonadal steroids appear to act directly in AVP‐expressing cells within the BST and CMA, because the majority of AVP‐ir cells in these areas contain oestrogen and androgen receptor immunoreactivity. Recently, we have localised progestin receptor immunoreactivity in virtually all of the AVP‐ir cells in the BST and CMA. To understand the role played by progestin receptors in AVP cells within the BST and CMA, we treated male rats with 1 mg of progesterone or oil for 5 days, and then examined AVP immunoreactivity within the brain. We found that progesterone decreased AVP‐ir labelling within the BST and CMA, as well as in two of the projection sites of these cells, the lateral septum and lateral habenula. Progesterone treatment did not alter testosterone secretion from the testes, nor did it alter adult male sexual behaviour. These data illustrate an additional mechanism by which the AVP cells in the BST and CMA can be regulated. These data also suggest that progesterone may act in the male brain to influence behaviours that are AVP‐dependent.