bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitric Oxide Is Associated with Long-Term Zinc Tolerance in Solanum nigrum
Authors: Xu Jin , Yin Hengxia , Li Yulong , Liu Xiaojing
Published: September 2010

Nitric oxide (NO) has been identified as a signal molecule that interplays with reactive oxygen species in response to heavy metal stresses. Roles of NO in regulating cadmium toxicity and iron deficiency have been proposed; however, the function of NO in zinc (Zn) tolerance in plants remains unclear. Here, we investigated NO accumulation and its role in plant Zn tolerance. Zn-induced NO production promoted an increase in reactive oxygen species accumulation in Solanum nigrum roots by modulating the expression and activity of antioxidative enzymes. Subsequently, programmed cell death (PCD) was observed in primary root tips. Inhibiting NO accumulation by 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (a specific NO scavenger) or NG-nitro-l-arginine-methyl ester (a NO synthase inhibitor) prevented the increase of superoxide radical and hydrogen peroxide as well as the subsequent cell death in the root tips, supporting the role of NO in Zn-induced PCD in the root tips. Zn-induced NO production affected the length of primary roots, the number of lateral roots, and root hair growth and thereby modulated root system architecture and activity. Investigation of metal contents in Zn-treated roots suggests that NO is required for metal (especially iron) uptake and homeostasis in plants exposed to excess Zn. Taken together, our results indicate that NO production and the subsequent PCD in root tips exposed to excess Zn are favorable for the S. nigrum seedling response to long-term Zn toxicity by modulating root system architecture and subsequent adaptation to Zn stress.
The Role of the Senior HR Executive in Japan and the United States: Employment Relations, Corporate Governance, and Values
Authors: JACOBY SANFORD M. , NASON EMILY M. , SAGUCHI KAZURO
Published: September 2010

Based on an original survey of senior human resources (HR) executives, this paper provides empirical data for a comparison of HR management structures and practices in Japan and the United States. In both countries, the headquarters HR function has shrunk and employment decisions have become more decentralized in recent years. However, because the pace of change has been more rapid in the United States, the gap with Japan has widened. Significant differences persist in other areas, such as the HR executive's role in strategic decisions, perceived power of the HR function, executive values, and the consequences of these values for organizational outcomes and corporate governance.
The Intergenerational Supply of Loggers Under Conditions of Declining Economic Well‐Being
Authors: GOLDSTEIN JONATHAN P. , IRLAND LLOYD C. , SENICK JENNIFER A. , BASSETT ERIC W.
Published: September 2010

This paper addresses the supply‐side explanations of a logger shortage by estimating an occupational choice model that considers the role of earnings, nonpecuniary determinants and intergenerational factors. Our results showed that: (1) relative earnings have no statistically significant effect on career choice; (2) improvement in the public image of loggers substantially increases entry into logging; and (3) a strong intergenerational supply linkage exists but is currently being eroded.
Unions and Discriminatory Hiring: Evidence from New Zealand
Authors: HARCOURT MARK , LAM HELEN , HARCOURT SONDRA
Published: September 2010

This study examines the effects of unions on employer compliance with antidiscrimination legislation in New Zealand, using a sample of 227 employers. The results do indicate that unions do reduce discriminatory practices. More specifically, higher levels of unionization do increase the level of employer compliance. However, other union characteristics, such as union size and strike propensity, appeared to have no influence on employer practice.
‘Clarity’ Begins at Home: An Examination of the Conceptual Underpinnings of the IAASB's Clarity Project
Authors: Dennis Ian
Published: September 2010

This paper examines the IAASB's policy proposals arising out of their review of the drafting conventions in auditing standards that has become known as the Clarity Project. The objectives of the Project and how they changed during its evolution are reviewed. One motivation for the Project was to ensure that auditing standards drafted by the IAASB are ‘principles‐based’. The failure to adequately consider the meaning of ‘principles‐based standards’ was responsible for a lack of clear focus on what was wanted from the Project. This resulted in two main objectives for the Project. The first was a search for fundamental principles of auditing that was incompletely realized, officially abandoned and subsequently covertly pursued in the revisions made to ISA 200. The second was a desire to promulgate standards that were ‘objectives‐based’ or ‘principles‐based’. Unfortunately, there was inadequate enquiry into the idea of an objective and the related idea of ‘objectives‐based’ standards. The paper clarifies their nature. It examines the idea of a conceptual framework for auditing and the explanations of objectives and ‘objectives‐based’ standards that emerged during the evolution of the Project. It considers the ideas objectives in ISAs, requirements and explanatory material in order to throw light on the nature of auditing standards that contain them. The question of whether an important distinction between ‘requirements’ and ‘presumptive requirements’ has been lost between the first and the second Exposure Draft is examined. This distinction can be explained and justified in terms of a distinction between different concepts of rules. It is suggested that the Clarity Project was a missed opportunity. The results are uncertain because there was a failure to undertake adequate conceptual enquiry into some of the concepts that directed its development. A start is made in rectifying this omission in the paper.
Opportunities for Task‐Level Research within the Audit Process
Authors: Messier, Jr. William F.
Published: September 2010

This essay discusses selected areas within the audit process where audit research has contributed to our understanding of important audit issues and areas that are in need of further investigation. The focus of the discussion is at the task level. Areas cited for further research include the use of specialists, reliance on the internal audit function, related parties, analytical procedures, brainstorming, assessing business risks, materiality, and professional scepticism. Potential research questions are identified.
The handover process and triage of ambulance‐borne patients: the experiences of emergency nurses
Authors: Bruce Karin , Suserud Björn‐Ove
Published: September 2010

One of the most important tasks that a nurse faces in the emergency room, when receiving a patient, is handover and the triage function. The aim of the study was to explore the experiences of nurses receiving patients who were brought into hospital as emergencies by ambulance crews through an analysis of the handover and triage process. A qualitative descriptive interview study inspired by the phenomenological method was used with six emergency nurses. There are three elements to a handover: a verbal report, handing over documented accounts and the final symbolic handover when a patient is transferred from the ambulance stretcher onto the hospital stretcher. The study identified that the verbal communication between ambulance and emergency nurses was often very structured. The ideal handovers often involved patients with very distinct medical problems. The difficult handover or the ‘non‐ideal’ one was characterized by a significantly more complicated care situation. The handover function was pivotal in ensuring that the patient received the correct care and that care was provided at the appropriate level. The most seriously afflicted patients arrived by ambulance; therefore, the interplay between pre‐hospital and hospital personnel was vital in conveying this important information. To some extent, this functioned well, but this research has identified areas where this care can be improved.
An evaluation of the contribution of critical care outreach to the clinical management of the critically ill ward patient in two acute NHS trusts
Authors: Chellel Annie , Higgs Debbie , Scholes Julie
Published: September 2010

This paper reports on an evaluation of the role and contribution of outreach in the management of the critically ill ward patient using Stake's Responsive Model (Stake, 1975) and case study methodology (Simons, 1980). Twenty cases were examined, purposefully sampling all staff involved in the case identified by an initial interview with the outreach nurse. In total, 80 interviews were carried out, 20 with the outreach nurses and 54 with other members of health care teams involved in the cases, and six further targeted in‐depth interviews with senior anaesthetic and nursing staff. The outreach contribution which emerged from the data analysis consisted of four core categories: action (getting things done, getting decisions made and following through), focusandvision (concentrating on one patient and having a vision of what action was needed to meet their care needs), orchestration (a communication and co‐ordinating role) and expertise (bringing critical care skills and experience to the bedside). These categories were validated and developed in the six in‐depth interviews. Three themes emerged from the data describing aspects of the acute care context in which outreach operates. The interviews revealed a battleweary workforce overwhelmed by the complex and increased demands of the critically ill ward patient. The medical and nursing teams at the bedside are inexperienced and often unsupported by senior clinical decision‐makers. This is dealt with by ‘passing the buck’ creating gaps and delays in care management which are the problems addressed by the outreach contribution. Outreach may solve problems for the critically ill ward patient, but the underlying causes remain poorly understood.
Body positioning and its effect on oxygenation – a literature review
Authors: Marklew Anna
Published: September 2010

Evidence‐based health care has become a priority in the National Health Service (NHS), with increased emphasis on clinical practices that are grounded in quality evidence rather than those that persist because of tradition. Turning and positioning of patients are well‐accepted nursing activities. Appropriate positioning of the critically ill patient can dramatically improve gas exchange, resulting in a shorter stay in the critical care unit and an improved outcome. This study reviews the current published literature on the subject of positioning and gas exchange, with emphasis on oxygenation. Conclusions made from this study are that nurses need to be aware of how different positions can affect patients' oxygenation. Further research on exploring patients' experience of positioning within the critical care environment and nurses' understanding of positioning and oxygenation is needed.
Pre‐registration education: making a difference to critical care?
Authors: Collins Timothy J , Price Ann M , Angrave Philip D
Published: September 2010

This paper aims to discuss the development of a pre‐registration high‐dependency nursing programme and evaluate its effects on student's perceived learning and confidence in managing critically ill patients. The programme consists of two modules that compliment one another, ‘Care of the Acutely Ill Adult’ focuses on a variety of disease processes and subsequent nursing care. Whilst the second module titled ‘Caring for the Highly Dependant/Critically Ill Adult’ focuses on assessment skills related to critically ill patients. The paper explores the content and delivery of the modules including the advantages and disadvantages of implementing them. Student evaluation from 59 nursing students found that student's knowledge, assessment skills and management of the critically ill patient had improved since completing the modules. Nurse Consultants, intensive therapy unit matrons and Critical Care Outreach nurses have acknowledged an increase in the number of nursing students identifying and referring critically ill patients to outreach teams. They also stated improvements in nurse recruitment in critical care since commencement of the modules.
Development of the Children's Attributions about Psychological Problems in their Peers Scale
Authors: Swords L. , Hennessy E. , Heary C.
Published: September 2010

Background  Research has shown that children's beliefs about the causes of psychological problems are related to their attitudes and reactions towards affected peers. This study describes the development of the Children's Attributions about Psychological Problems in their Peers (CAPPP) Scale, which assesses children's beliefs about the causes of an internalizing and an externalizing condition.

Methods  The 16 items comprising the CAPPP are derived from previous qualitative research findings. Five hundred and ninety‐five young people, drawn from five different age groups spanning early childhood to late adolescence, completed a CAPPP Scale for each of two vignettes describing the behaviour of hypothetical peers with attention deficit hyperactivity disorder (ADHD) and depression.

Results  Modifications following consideration of psychometric properties and conceptual fit resulted in a 12‐item scale. For both the ADHD and depression conditions, the components that emerged were ‘Volition’, ‘Recent Life Stress’, ‘Family Factors’ and ‘School Factors’.

Conclusions  The present study represents the first field trial of the CAPPP. Results suggest that children's and adolescents' beliefs about the causes of psychological problems are multidimensional and incorporate both individual and environmental factors.
Acute exacerbations of fibrotic interstitial lung disease
Authors: Churg Andrew , Wright Joanne L , Tazelaar Henry D
Published: September 2010

Churg A, Wright J L & Tazelaar H D (2011) Histopathology 58, 525–530 Acute exacerbations of fibrotic interstitial lung disease

An acute exacerbation is the development of acute lung injury, usually resulting in acute respiratory distress syndrome, in a patient with a pre‐existing fibrosing interstitial pneumonia. By definition, acute exacerbations are not caused by infection, heart failure, aspiration or drug reaction. Most patients with acute exacerbations have underlying usual interstitial pneumonia, either idiopathic or in association with a connective tissue disease, but the same process has been reported in patients with fibrotic non‐specific interstitial pneumonia, fibrotic hypersensitivity pneumonitis, desquamative interstitial pneumonia and asbestosis. Occasionally an acute exacerbation is the initial manifestation of underlying interstitial lung disease. On biopsy, acute exacerbations appear as diffuse alveolar damage or bronchiolitis obliterans organizing pneumonia (BOOP) superimposed upon the fibrosing interstitial pneumonia. Biopsies may be extremely confusing, because the acute injury pattern can completely obscure the underlying disease; a useful clue is that diffuse alveolar damage and organizing pneumonia should not be associated with old dense fibrosis and peripheral honeycomb change. Consultation with radiology can also be extremely helpful, because the fibrosing disease may be evident on old or concurrent computed tomography scans. The aetiology of acute exacerbations is unknown, and the prognosis is poor; however, some patients survive with high‐dose steroid therapy.
Functional test of the influence ofWolbachiagenes on cytoplasmic incompatibility expression inDrosophila melanogaster
Authors: Yamada R. , Iturbe‐Ormaetxe I. , Brownlie J. C. , O'Neill S. L.
Published: September 2010

Wolbachiaare inherited intracellular bacteria that infect a broad range of invertebrate hosts. They commonly manipulate host reproduction in a variety of ways and thereby favour their invasion into host populations. While the biology ofWolbachiahas been extensively studied at the ecological and phenotypic level, little is known about the molecular mechanisms underlying the interaction betweenWolbachiaand their hosts. Recent comparative genomics studies ofWolbachiastrains have revealed putative candidate genes involved in the expression of cytoplasmic incompatibility (CI) in insects. However the functional testing of these genes is hindered by the lack of available genetic tools inWolbachia. To circumvent this problem we generated transgenicDrosophilalines expressing variousWolbachiaCI candidate genes under the control of the GAL4/UAS system in order to evaluate their possible role inWolbachia‐related phenotypes inDrosophila. The expression of a number of these genes inDrosophila melanogasterfailed to mimic or alter CI phenotypes across a range ofWolbachiabackgrounds or in the absence ofWolbachia.
Differential transcription of two highly divergent gut‐expressed Bm86 antigen gene homologues in the tick Rhipicephalus appendiculatus (Acari: Ixodida)
Authors: Kamau L. , Skilton R. A. , Odongo D. O. , Mwaura S. , Githaka N. , Kanduma E. , Obura M. , Kabiru E. , Orago A. , Musoke A. , Bishop R. P.
Published: September 2010

The transcriptional control of gene expression is not well documented in the Arthropoda. We describe transcriptional analysis of two exceptionally divergent homologues (Ra86) of the Bm86 gut antigen from Rhipicephalus appendiculatus. Bm86 forms the basis of a commercial vaccine for the control of Rhipicephalus (Boophilus) microplus. The R. appendiculatus Ra86 proteins contain 654 and 693 amino acids, with only 80% amino acid sequence identity. Reverse‐transcription PCR of gut cDNA showed transcription of only one genotype in individual female ticks. PCR amplification of 3′ untranslated sequences from genomic DNA indicated that both variants could be encoded within a single genome. When both variants were present, one of the two Ra86 genotypes was transcriptionally dominant.
PsOr1, a potential target for RNA interference‐based pest management
Authors: Zhao Y. Y. , Liu F. , Yang G. , You M. S.
Published: September 2010

Insect pests cause billions of dollars in agricultural losses, and attempts to kill them have resulted in growing threats from insecticide resistance, dietary pesticide pollution and environmental destruction. New approaches to control refractory insect pests are therefore needed. The host‐plant preferences of insect pests rely on olfaction and are mediated via a seven transmembrane‐domain odorant receptor (Or) family. The present study reports the cloning and characterization of PsOr1, the first candidate member of the Or gene family from Phyllotreta striolata, a devastating beetle pest that causes damage worldwide. PsOr1 is remarkably well conserved with respect to other insect orthologues, including DmOr83b from Drosophila melanogaster. These insect orthologues form an essential non‐conventional Or sub‐family and may play an important and generalized role in insect olfaction. We designed double‐stranded (ds) RNA directly against the PsOr1 gene and exploited RNA interference (RNAi) to control P. striolata. The chemotactic behavioural measurements showed that adult beetles were unable to sense the attractant or repellent odour stimulus after microinjection of dsRNA against PsOr1. Reverse Transcription (RT)‐PCR analysis showed specific down‐regulation of mRNA transcript levels for this gene. Furthermore, host‐plant preference experiments confirmed that silencing PsOr1 by RNAi treatment impaired the host‐plant preferences of P. striolata for cruciferous vegetables. These results demonstrate that this insect control approach of using RNAi to target PsOr1 and its orthologues might be effective in blocking host‐plant‐seeking behaviours in diverse insect pests. The results also support the theory that this unique receptor type plays an essential general role in insect olfaction.
Gper and ESRs are expressed in rat round spermatids and mediate oestrogen‐dependent rapid pathways modulating expression of cyclin B1 and Bax
Authors: Chimento A. , Sirianni R. , Zolea F. , Bois C. , Delalande C. , Andò S. , Maggiolini M. , Aquila S. , Carreau S. , Pezzi V.
Published: September 2010

Spermatogenesis is a precisely controlled and timed process, comprising mitotic divisions of spermatogonia, meiotic divisions of spermatocytes, maturation and differentiation of haploid spermatids giving rise to spermatozoa. It is well known that the maintenance of spermatogenesis is controlled by gonadotrophins and testosterone, the effects of which are modulated by a complex network of locally produced factors, including oestrogens. However, it remains uncertain whether oestrogens are able to activate rapid signalling pathways directly in male germ cells. Classically, oestrogens act by binding to oestrogen receptors (ESRs) 1 and 2. Recently, it has been demonstrated that rapid oestrogen action can also be mediated by the G‐protein‐coupled oestrogen receptor 1 (Gper). The aim of the present study was to investigate ESRs and Gper expression in primary cultures of adult rat round spermatids (RS) and define if oestradiol (E2) is able to activate, through these receptors, pathways involved in the regulation of genes controlling rat RS apoptosis and/or maturation. In this study, we demonstrated that rat RS express ESR1, ESR2 and Gper. Short‐time treatment of RS with E2, the selective Gper agonist G1 and the selective ESR1 and ERβ agonists, 4,4′,4″‐(4‐propyl‐[1H]pyrazole‐1,3,5‐triyl) trisphenol (PPT) and 2,3‐bis(4‐hydroxyphenyl)‐propionitrile (DPN), respectively, determined activation of Extra‐cellular signal‐regulated kinase (ERK1/2) through the involvement of epidermal growth factor receptor transactivation. In addition, we investigated the effects of ESRs and Gper pathway activation on factors involved in RS maturation. Expression of cyclin B1 mRNA was downregulated by E2, G1 and PPT, but not by DPN. A concomitant and inverse regulation of the pro‐apoptotic factor Bax mRNA expression was observed in the same conditions, with DPN being the only one determining an increase in this factor expression. Collectively, these data demonstrate that E2 activates, through ESRs and Gper, pathways involved in the regulation of genes controlling rat RS apoptosis and differentiation such as cyclin B1 and Bax.
Factors influencing the evolution of clutch size in a gregarious insect parasitoid
Authors: Zaviezo Tania , Mills Nick
Published: September 2010

1. In this study we examined the clutch size of Hyssopus pallidus (Askew) (Hymenoptera, Eulophidae), a gregarious ectoparasitoid of codling moth (Lepidoptera, Tortricidae) larvae that is characterized by a host handling time of 2 days approximately.

2. Clutch size increased asymptotically with host larval size (fresh weight) to a maximum of 32 eggs. A single male developed from each clutch, brood survival was 83% and pupal size of female offspring was 0·45 mg, all independent of clutch size.

3. A comparison of the response of both experienced and naïve adult parasitoids to varying host larval size, indicated that experience was not necessary for H. pallidus to be able to accurately estimate host size.

4. Clutch size increased by 50% for medium size host larvae (30–40 mg) and 83% for large host larvae (60–76 mg) when the encounter rate was reduced from one host every second day to one every seventh day. A significantly lower clutch size was produced on the last day at the highest encounter rate for large host larvae, suggesting exhaustion of the egg supply for H. pallidus.

5. Manipulation of parasitoid clutch size on constant size host larvae did not influence sex ratio (single male) or brood survival (93%), but produced a linear trade‐off between clutch size and the size (fresh weight) of female pupae. Longevity, lifetime fecundity, total number of hosts attacked, and clutch size all increased linearly with the adult size (female pupal weight).

6. The observed clutch size in newly emerged H. pallidus is consistent with a strategy of maximizing lifetime fitness gain rather than the gain from individual hosts (Lack clutch size) despite a significant investment in the time required to attack each host.
A world‐wide study of high altitude treeline temperatures
Authors: Körner Christian , Paulsen Jens
Published: September 2010

Aim  At a coarse scale, the treelines of the world's mountains seem to follow a common isotherm, but the evidence for this has been indirect so far. Here we aim at underpinning this with facts.

Location  We present the results of a data‐logging campaign at 46 treeline sites between 68° N and 42° S.

Methods  We measured root‐zone temperatures with an hourly resolution over 1–3 years per site between 1996 and 2003.

Results  Disregarding taxon‐, landuse‐ or fire‐driven tree limits, high altitude climatic treelines are associated with a seasonal mean ground temperature of 6.7 °C (±0.8 SD; 2.2 K amplitude of means for different climatic zones), a surprisingly narrow range. Temperatures are higher (7–8 °C) in the temperate and Mediterranean zone treelines, and are lower in equatorial treelines (5–6 °C) and in the subarctic and boreal zone (6–7 °C). While air temperatures are higher than soil temperatures in warm periods, and are lower than soil temperatures in cold periods, daily means of air and soil temperature are almost the same at 6–7 °C, a physics driven coincidence with the global mean temperature at treeline. The length of the growing season, thermal extremes or thermal sums have no predictive value for treeline altitude on a global scale. Some Mediterranean (Fagus spp.) and temperate South Hemisphere treelines (Nothofagus spp.) and the native treeline in Hawaii (Metrosideros) are located at substantially higher isotherms and represent genus‐specific boundaries rather than boundaries of the life‐form tree. In seasonal climates, ground temperatures in winter (absolute minima) reflect local snow pack and seem uncritical.

Main conclusions  The data support the hypothesis of a common thermal threshold for forest growth at high elevation, but also reflect a moderate region and substantial taxonomic influence.
Quaking aspen (Populus tremuloidesMichx.) at treeline: a century of change in the San Juan Mountains, Colorado, USA
Authors: Elliott Grant P. , Baker William L.
Published: September 2010

During a repeat photography study quaking aspen (Populus tremuloidesMichx.) was observed invading conifer stands at treeline in the San Juan Mountains of south‐western Colorado. Aspen tree core samples were collected from nine plots ranging in elevation from 3192 to 3547 m, and estimated dates of establishment of aspen were grouped into 10‐year intervals for analysis. Estimated periods of establishment were compared with century‐long climate data records to derive any correlations with aspen invasion. Other disturbance agents, such as fire and livestock grazing were also considered. Quantitative analysis of climate variables suggests that decreased mean spring precipitation and increased mean summer maximum temperature provide optimal conditions for aspen establishment. Episodes of invasion were non‐synchronous, but all occurred after 1900, and are likely from seed germination, considered unusual in aspen. Different climate variables explain stand initiation from seed and subsequent peak establishment from vegetative reproduction. Long‐term climate records indicate a general warming since the beginning of the 20th century and explain the continued invasion and persistence of aspen at treeline, resulting from asexual reproduction. Short‐term climate records identify anomalously cool, moist years that explain rarely observed sexual reproduction in aspen.
Areas of endemism of vascular plants in the Eastern Alps in relation to Pleistocene glaciation
Authors: Tribsch Andreas
Published: September 2010

Aim  The central aim of this paper is to localize areas of endemism of the vascular plant flora in the Eastern Alps. Moreover, causes for location and limits of the areas of endemism are assessed.

Location  The study area includes the Eastern European Alps and adjacent lowland areas.

Methods  Analyses were based on 288 vascular plant taxa endemic to the study region, scored in 115 operational geographic units, which were predominantly mountain ranges. For each of these units, number of endemic taxa, range down weighted endemism, environmental variables, elevation of the last glacial maximum ice sheet, and elevation of the snowline during the last glacial maximum, were estimated. To evaluate the relationships between the geographical areas, the presence/absence matrix of endemics in areas was used to calculate phenograms and cladograms. Values from the range down weighted endemism superimposed on phenograms and cladograms were used to indicate areas of endemism. Linear regressions between richness in endemism and environmental as well as palaeo‐environmental variables were used to infer causes of the observed patterns of endemism.

Results  The endemic taxa of the Eastern Alps show a very uneven distribution, the majority being confined to one or few mountain ranges. High levels of endemism are found in the southern, southeastern, easternmost, and northeastern Eastern Alps. Trees obtained from phenetic and cladistic methods were largely congruent. Seven areas of endemism were clearly delimited, all in regions that are regarded as glacial refugia. Two of them are located on siliceous, four on calcareous bedrock. Not all endemic taxa, however, grow in the areas of endemism. Therefore, enlargement areas are suggested. Linear regression showed a significant correlation between high endemism and low glacial ice cover, but not with other environmental variables.

Main conclusions  Vicariance resulting from Pleistocene glaciations is the most important factor causing distributional patterns of endemic plants and the formation of areas of endemism. Mapping values of weighted endemism onto trees facilitated delimitation and definition of the areas of endemism. Because of their strong dependence on siliceous bedrock and the resulting disjunct distributional patterns of some taxa in the Southern Alps, the inclusion of a few operational geographic units with high levels of endemism was not supported by the analyses. Despite post‐vicariant dispersal that causes problems in analyses of areas of endemism, the circumscription of areas of endemism in the Eastern Alps was possible to a satisfactory extent. Other methodological approaches, however, which include concepts of post‐vicariant dispersal and that allow overlap of areas of endemism would be highly useful.
Explaining grass‐nutrient patterns in a savanna rangeland of southern Africa
Authors: Mutanga Onisimo , Prins Herbert H.T. , Skidmore Andrew K. , van Wieren Sipke , Huizing Herman , Grant Rina , Peel Mike , Biggs Harry
Published: September 2010

Aim  The search for possible factors influencing the spatial variation of grass quality is an important step towards understanding the distribution of herbivores, as well as a step towards identifying crucial areas for conservation and restoration. A number of studies have shown that grass quality at a regional scale is influenced by climatic variables. At a local scale, site factors and their interaction are considered important. In this study, we aimed at examining environmental correlates of grass quality at a local scale. The study also sought to establish if biotic factors interact significantly with abiotic factors in influencing a variation in grass quality.

Location  The study area is located in the Kruger National Park of South Africa. The study area stretches from west (22°49′ S and 31°01′ E) to east, (22°44′ S and 31°22′ E) covering an area of about 25 × 6 km in the far northern region of the Kruger National Park.

Methods  We collected environmental data such as soil texture, percentage grass cover and biomass as well as grass samples for chemical analysis from specific locations in the study area. In addition, a digital elevation model (DEM) with a resolution of 5 m was used to derive elevation, slope and aspect using a geographic information system (GIS), which were related to grass quality. We used correlation analysis and anova to relate environmental variables to grass quality. Multivariate analysis techniques were used to simultaneously analyse and explore the complex interactions between variables.

Results and conclusions  Our results indicate that there is a significant relationship between grass quality parameters and site‐specific factors such as slope, altitude, percentage grass cover, aspect and soil texture. Relatively, percentage grass cover and soil texture were more critical in explaining a variation in grass quality. Plant characteristics such as species type interact significantly with slope, altitude and geology in influencing nutrient distribution. The results of this study may give a better insight on foliar nutrient distribution patterns at a landscape scale in savanna rangelands. Furthermore, the results of this study may help in the selection of ancillary information, which could be used in conjunction with other data such as remotely sensed data to map grass quality – an important step towards understanding the distribution and feeding patterns of wildlife. However, we acknowledge that this study is based on one seasonal snapshot, therefore some slightly different findings may be obtained during other times of the year. Nevertheless, the study has revealed that under the conditions experienced during the study period, nutrient distribution varies with varying biotic and abiotic factors.
An altitudinal comparison of caterpillar (Lepidoptera) assemblages on Ficus trees in Papua New Guinea
Authors: Novotny Vojtech , Miller Scott E. , Basset Yves , Cizek Lukas , Darrow Karolyn , Kaupa Borenke , Kua Joseph , Weiblen George D.
Published: September 2010

Aim  This analysis of caterpillar (Lepidoptera) beta‐diversity between tropical lowlands and highlands attempts to separate the effects of between‐site (1) turnover of herbivore species on particular host plants, (2) changes in host use by herbivores, and (3) turnover of plant species on changes in herbivore assemblages.

Location  Two rain forest areas 130 km and 1700 altitudinal metres apart were studied in Papua New Guinea: one in the lowlands (100 m a.s.l.) on the northern coast of the island and one in the central New Guinean cordillera at 1800 m a.s.l.

Methods  The analysis is based on caterpillar feeding records obtained by quantitative sampling and rearing of caterpillars from four Ficus species studied in the mountains and 21 Ficus species and 62 plant species from other genera and families studied in the lowlands, including three Ficus species studied in both areas.

Results  Only 17% of species feeding on Ficus in the highlands also occurred in the lowlands. These species represented 1–46% of individuals in caterpillar assemblages on particular Ficus hosts. Widespread species included both Ficus specialists and generalists feeding on numerous plant families. Some of the Ficus specialists changed their preferred host species with altitude. High species turnover was not explained by changes in the species composition of host plants with altitude as lowland and montane assemblages feeding on the same Ficus species showed high turnover. Despite the rarity of widespread caterpillars, the lowland and montane Ficus assemblages were remarkably similar in their dominance structure, species richness, host specificity, generic composition and familial composition.

Main conclusions  Ficus‐feeding Lepidoptera assemblages between tropical lowlands and highlands are characterized by substantial species turnover not explained by altitudinal changes in the composition of the vegetation. Further, species‐rich plant genera can support caterpillar assemblages with relatively low beta‐diversity compared with species‐poor genera as caterpillars can switch their host preferences from one congeneric host species to another along an altitudinal gradient. Closely related plant species can thus represent a broad, continuously distributed resource along such gradients.
A hypothetico‐deductive analysis of the environmental factors involved in the current reptile distribution pattern in the Canary Islands
Authors: Guerrero José C. , Mario Vargas J. , Real Raimundo
Published: September 2010

Aim  We analyse the influence of different factors on the inter‐insular colonization processes that yielded the current distribution pattern of endemic reptile species in the Canary Islands.

Location  The seven main islands of the Canary Islands.

Methods  We tested 11 hypotheses about factors that might have affected the colonization processes. We used Mantel and partial Mantel tests to establish the statistical significance of the relationship between the islands predicted by each hypothesis, and a parsimony analysis to detect the most parsimonious hypothesis.

Results  The only significant relationships were those predicted by inter‐island distance, also taking area into account, and habitat similarity, considering current vegetation in the islands. The latter was the best hypothesis according to the parsimony criterion.

Main conclusions  Our results support the hypothesis that habitat similarity between islands is the main factor affecting the colonization processes of the whole group, although inter‐insular distance seems to play a separate role in colonization events.
Inferring the mode of speciation in Indo‐West PacificConus(Gastropoda: Conidae)
Authors: Vallejo Benjamin
Published: September 2010

Aim This study aims to initially explore the mode of speciation in Indo‐West PacificConus.

Location The Indo‐West Pacific island arc, Indian and Pacific Oceans.

Methods Relating evolutionary divergence in a molecular phylogeny [T.F. Duda & S.R. Palumbi (1999)Proceedings of the National Academy of Science USA,96, 10272] using node height with modern range extents as a possible measure of allopatric or sympatric speciation following that of T.G. Barraclough, A.P. Vogler & P.H. Harvey [(1999)Evolution of Biological Diversity. Oxford University Press, Oxford] models of sympatric and allopatric speciation.

Results The analysis seems to indicate that the relationship of sympatry with node height is not informative. Species that have diverged quite recently show 100% sympatry with the sister species. A clearer signal of recent allopatric speciation is observed in species whose distribution is at the edge of the Indian and Pacific Ocean basins. In the widely distributedConus ebraeusclade, the relationships of node heights and range extents of the member species support a key prediction of sympatric speciation. In highly ecologically specialized species, there is a smaller degree of sympatry than those species that are less specialized.

Main conclusions The modes of speciation models presented in this study are not informative. This suggests that there had been large and possibly rapid changes in range size after speciation in the various clades. This could have been due to the fact that the wide dispersal life‐history strategy in the genus had been largely conserved inConusevolution. There is evidence of sympatric and parapatric speciation in oneConusclade. Overall, the patterns of phylogeny and range distribution when related to the timing of speciation lend circumstantial support to a Neogene centre of origin hypothesis but not to speciation on the Pacific Plate. Speciation is likely to have been associated with the Tethys Sea closure event, with rapid speciation occurring after closure.
Patterns of endemism of the eastern North American cave fauna
Authors: Christman Mary C. , Culver David C. , Madden Molly K. , White Denis
Published: September 2010

Aim  Over 250 species of obligate terrestrial cave‐dwelling animals (troglobionts) are known from single caves in the eastern United States. We investigate their geographical distribution, especially in relation to other troglobionts. We relate these patterns to taxonomic group, opportunities for dispersal and geographical location.

Location  Caves of the United States east of the Mississippi River.

Methods  We associated over 3000 records of more than 450 troglobiotic species and subspecies with hexagons of 1000, 5000 and 10,000 km2 in size. We calculated Moran's I, black–white joins and cubic regression of endemics on non‐endemics at all three spatial scales. For 5000 km2 hexagons, we modelled the spatial autocorrelation of the residuals of the cubic regression of endemics on non‐endemics.

Results  Differences among orders in percentage single‐cave endemism were not significant, except for Pseudoscorpionida, which was higher (69%) than any other order. At all three scales, Moran's I and black–white joins were significant, indicating a clumped distribution of both single‐cave endemics and other troglobionts. Spatial patterns were similar at all three scales and Moran's I was highest at 5000 km2. The cubic fit of endemics to non‐endemics was consistently better, with less systematic error or residuals, than were linear or quadratic models. Residuals showed a significant geographical pattern with excess endemics in more southerly locations.

Main conclusions  There was both a non‐spatial and spatial component to the pattern of single‐cave endemism. The non‐spatial component was the association of high levels of single‐cave endemism with areas of high diversity of non‐endemics. It may be that both are high because of high secondary productivity. Spatially, single‐cave endemism is high in central rather than peripheral areas and in the southern part of the range. It is not higher in areas of more dissected limestone, which would reduce migration rates; if anything endemism is lower. Regional spatial effects are important, indicating that cave communities cannot be understood (or protected) in isolation.
The fourth paradigm pattern of post‐glacial range expansion of European terrestrial species: the phylogeography of the Marbled White butterfly (Satyrinae, Lepidoptera)
Authors: Habel Jan Christian , Schmitt Thomas , Müller Paul
Published: September 2010

Aim  Three paradigm patterns of post‐glacial dispersal are known for terrestrial species in Europe. However, the possibility of a fourth arises with the Italian and the Balkan lineages expanding to central Europe and the Iberian one being trapped by the Pyrenees. We test this hypothesis by analysing the molecular biogeography of the Marbled White butterfly.

Location  Twelve populations distributed over a major part of the European range of Melanargia galathea and M. lachesis.

Methods  We studied 18 allozyme loci of 403 individuals from 12 populations. Butterflies were sampled in the field, frozen in liquid nitrogen and stored under these conditions until analysis. We used cellulose acetate plates for allozyme electrophoresis.

Results  We detected three major genetic lineages within the M. galathea/lachesis complex. The M. lachesis sample from the southern Pyrenees was strongly genetically differentiated from M. galathea (FCT: 0.312). Melanargia galathea splits into two major genetic lineages (FCT: 0.115), which both were found in post‐glacially invaded regions. The further differentiation within these lineages was comparably low (FSC: 0.028). The genetic diversity within populations was high compared with other butterfly species.

Main conclusions  Our findings support the existence of a fourth pattern with only the Iberian lineage not contributing considerably to the post‐glacial colonization of central Europe. Preliminary studies in other butterfly species of dry grasslands support the importance of this pattern possibly representing a fourth paradigm. The high genetic diversity within populations might be one reason for the recently observed expansions at the northern distribution limits.
Do fleas (Insecta: Siphonaptera) parallel their mammal host diversification in the Mexican transition zone?
Authors: Morrone Juan J. , Gutiérrez Ana
Published: September 2010

Aim The Mexican transition zone is a complex area where Neotropical and Nearctic biotic elements overlap. A previous study on mammal species has shown a great diversification in the area. We analyse the diversification of their flea species (Insecta: Siphonaptera), in order to determine if a diversification similar to their mammal host species has occurred.

Location The area analysed corresponds to Mexico.

Methods The panbiogeographical or track analysis was based on the comparison of the individual tracks of 112 species belonging to 48 genera and eight families of the order Siphonaptera. Generalized tracks were obtained based on the comparison of the individual tracks. Nodes were found in the areas where generalized tracks overlapped.

Results Thirty‐four generalized tracks were obtained, distributed within the Mexican transition zone (20), the Nearctic region plus the Mexican transition zone (8), the Nearctic region (4) and the Neotropical region plus the Mexican transition zone (2). In the areas where they intersected, 26 nodes were identified: 23 in the Mexican transition zone and 3 in the Nearctic region.

Main conclusions The nodes are concentrated in the Transmexican Volcanic Belt (14), Sierra Madre Oriental (5) and Sierra Madre del Sur (4) provinces of the Mexican transition zone. These results show a significant diversification of the flea taxa, in parallel with the diversification of their mammal hosts.
Did tree‐Betula, Pinus and Picea survive the last glaciation along the west coast of Norway? A review of the evidence, in light of Kullman (2002)
Authors: Birks Hilary H. , Larsen E. , Birks H. J. B.
Published: September 2010

Aim  We discuss the hypotheses proposed by Kullman [Geo‐Öko21 (2000) 141; Nordic Journal of Botany21 (2001) 39; Journal of Biogeography29 (2002) 1117] on the basis of radiocarbon‐dated megafossils of late‐glacial age from the central Swedish mountains that boreal trees survived the glaciation along the south‐west coast of Norway and subsequently migrated eastward early in the late‐glacial to early deglaciated parts of the central Swedish Scandes mountains.

Methods  We assess these hypotheses on the basis of glacial geological evidence and four lines of palaeoecological evidence, namely macrofossil records of the tree species, vegetation and climate reconstructions from plant evidence, independent climate reconstructions from other proxies for the late‐glacial environment of south‐west Norway, and the patterns of post‐glacial spread of the tree species.

Location  South and west Norway, central Swedish Scandes mountains (Jämtland).

Results and conclusions  South‐west Norway and the adjacent continental shelf were under ice at the last‐glacial maximum (LGM). The late‐glacial vegetation of south‐west Norway was treeless and summer temperatures were below the thermal limits for Betula pubescens Ehrh., Pinus sylvestris L. and Picea abies (L.) Karst. Instead of spreading immediately after the onset of Holocene warming, as might have been expected if local populations were surviving, B. pubescens showed a lag of local arrival of 600 to > 1000 years, Pinus lagged by 1500 to > 2000 years, and Picea only reached southern Norway c. 1500 years ago and has not colonized most of south‐west Norway west of the watershed. Glacial geological evidence shows the presence of an ice sheet in the Scandes at the LGM and in the Younger Dryas, which was cold‐based near or at the area where the late‐glacial‐dated megafossils were recovered by Kullman. We conclude that the samples dated by Kullman (2002) should be evaluated carefully for possible sources of contamination. All the available evidence shows that the biogeographical hypotheses, based on these radiocarbon dates taken at face value, of late‐glacial tree survival at the Norwegian coast and subsequent eastwards spread to the mountains, are unsupportable.