bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective therapy of murine models of human leukemia and lymphoma with radiolabeled anti-CD30 antibody, HeFi-1
Authors: Zhang Meili , Yao Zhengsheng , Patel Hiral , Garmestani Kayhan , Zhang Zhuo , Talanov Vladimir S. , Plascjak Paul S. , Goldman Carolyn K. , Janik John E. , Brechbiel Martin W. , Waldmann Thomas A.
Published: May 2007

CD30 is a member of the TNF receptor superfamily. Overexpression of CD30 on some neoplasms versus limited expression on normal tissues makes this receptor a promising target for antibody-based therapy. Radioimmunotherapy of cancer with radiolabeled antibodies has shown promise. In this study, we evaluated the therapeutic efficacy of an anti-CD30 antibody, HeFi-1, armed with
211
At in a leukemia (karpas299) model and with
90
Y in a lymphoma (SUDHL-1) model. Furthermore, we investigated the combination therapy of
211
At-HeFi-1 with unmodified HeFi-1 in the leukemia model. Treatment with unmodified HeFi-1 significantly prolonged the survival of the karpas299-bearing mice compared with the controls (
P
< 0.001). Treatment with
211
At-HeFi-1 showed greater therapeutic efficacy than that with unmodified HeFi-1 as shown by survival of the mice (
P
< 0.001). Combining these two agents further improved the survival of the mice compared with the groups treated with either
211
At-HeFi-1 (
P
< 0.05) or unmodified HeFi-1 (
P
< 0.001) alone. In the lymphoma model, the survival of the SUDHL-1-bearing mice was significantly prolonged by the treatment with
90
Y-HeFi-1 compared with the controls (
P
< 0.001). In summary, radiolabeled HeFi-1 is very promising for the treatment of CD30-expressing leukemias and lymphomas, and the combination regimen of
211
At-HeFi-1 with unmodified HeFi-1 enhanced the therapeutic efficacy.
Trophic cascade facilitates coral recruitment in a marine reserve
Authors: Mumby Peter J. , Harborne Alastair R. , Williams Jodene , Kappel Carrie V. , Brumbaugh Daniel R. , Micheli Fiorenza , Holmes Katherine E. , Dahlgren Craig P. , Paris Claire B. , Blackwell Paul G.
Published: May 2007

Reduced fishing pressure and weak predator–prey interactions within marine reserves can create trophic cascades that increase the number of grazing fishes and reduce the coverage of macroalgae on coral reefs. Here, we show that the impacts of reserves extend beyond trophic cascades and enhance the process of coral recruitment. Increased fish grazing, primarily driven by reduced fishing, was strongly negatively correlated with macroalgal cover and resulted in a 2-fold increase in the density of coral recruits within a Bahamian reef system. Our conclusions are robust because four alternative hypotheses that may generate a spurious correlation between grazing and coral recruitment were tested and rejected. Grazing appears to influence the density and community structure of coral recruits, but no detectable influence was found on the overall size-frequency distribution, community structure, or cover of corals. We interpret this absence of pattern in the adult coral community as symptomatic of the impact of a recent disturbance event that masks the recovery trajectories of individual reefs. Marine reserves are not a panacea for conservation but can facilitate the recovery of corals from disturbance and may help sustain the biodiversity of organisms that depend on a complex three-dimensional coral habitat.
PI4P Promotes the Recruitment of the GGA Adaptor Proteins to the Trans-Golgi Network and Regulates Their Recognition of the Ubiquitin Sorting Signal
Authors: Wang Jing , Sun Hui-Qiao , Macia Eric , Kirchhausen Tomas , Watson Hadiya , Bonifacino Juan S. , Yin Helen L.
Published: May 2007

Phosphatidylinositol 4 phosphate (PI4P) is highly enriched in the trans-Golgi network (TGN). Here we establish that PI4P is a key regulator of the recruitment of the GGA clathrin adaptor proteins to the TGN and that PI4P has a novel role in promoting their recognition of the ubiquitin (Ub) sorting signal. Knockdown of PI4KIIα by RNA interference (RNAi), which depletes the TGN′s PI4P, impaired the recruitment of the GGAs to the TGN. GGAs bind PI4P primarily through their GAT domain, in a region called C-GAT, which also binds Ub but not Arf1. We identified two basic residues in the GAT domain that are essential for PI4P binding in vitro and for the recruitment of GGAs to the TGN in vivo. Unlike wild-type GGA, GGA with mutated GATs failed to rescue the abnormal TGN phenotype of the GGA RNAi-depleted cells. These residues partially overlap with those that bind Ub, and PI4P increased the affinity of the GAT domain for Ub. Because the recruitment of clathrin adaptors and their cargoes to the TGN is mediated through a web of low-affinity interactions, our results show that the dual roles of PI4P can promote specific GGA targeting and cargo recognition at the TGN.
MSVM-RFE: extensions of SVM-RFE for multiclass gene selection on DNA microarray data
Authors: Zhou Xin , Tuck David P.
Published: May 2007

Motivation: Given the thousands of genes and the small number of samples, gene selection has emerged as an important research problem in microarray data analysis. Support Vector Machine—Recursive Feature Elimination (SVM-RFE) is one of a group of recently described algorithms which represent the stat-of-the-art for gene selection. Just like SVM itself, SVM-RFE was originally designed to solve binary gene selection problems. Several groups have extended SVM-RFE to solve multiclass problems using one-versus-all techniques. However, the genes selected from one binary gene selection problem may reduce the classification performance in other binary problems.

Results: In the present study, we propose a family of four extensions to SVM-RFE (called MSVM-RFE) to solve the multiclass gene selection problem, based on different frameworks of multiclass SVMs. By simultaneously considering all classes during the gene selection stages, our proposed extensions identify genes leading to more accurate classification.

Contact:  david.tuck@yale.edu

Supplementary information: Supplementary materials, including a detailed review of both binary and multiclass SVMs, and complete experimental results, are available at Bioinformatics online.
First evidence for heritable variation in cooperative breeding behaviour
Authors: Charmantier Anne , Keyser Amber J , Promislow Daniel E.L
Published: May 2007

Understanding the evolution of complex social behaviours, such as cooperative breeding, is a fundamental problem in evolutionary biology, which has attracted much theoretical and empirical interest. Variation within and between species in the frequency of helping behaviour has been typically associated with variation in direct costs and benefits due to ecological constraints, or with indirect fitness payoffs (i.e. kin selection). Here, we provide the first evidence that individual variation in cooperative behaviour within a natural population also has a heritable component. Using a seven-generation pedigree in a wild population of western bluebirds (
Sialia mexicana
), we show significant heritable variation for the propensity to help rather than breed, as well as for the probability of having a helper at the nest. We also document a strong positive relationship between a bird's lifespan and its prospect of receiving help when breeding, in accordance with earlier comparative studies across species. These findings provide useful insights into the possible mechanisms which have led to the evolution of cooperative breeding and other social systems.
Genetic variation in life-history reaction norms in a marine fish
Authors: Hutchings Jeffrey A , Swain Douglas P , Rowe Sherrylynn , Eddington James D , Puvanendran Velmurugu , Brown Joseph A
Published: May 2007

Neither the scale of adaptive variation nor the genetic basis for differential population responses to the environment is known for broadcast-spawning marine fishes. Using a common-garden experimental protocol, we document how larval growth, survival and their norms of reaction differ genetically among four populations of Atlantic cod (Gadus morhua). These traits, and their plastic responses to food and temperature, differed across spatial scales at which microsatellite DNA failed to detect population structure. Divergent survival reaction norms indicate that warm-water populations are more sensitive to changes in food, whereas cold-water populations are more sensitive to changes in temperature. Our results suggest that neither the direction nor the magnitude of demographic responses to environmental change need be the same among populations. Adaptive phenotypic plasticity, previously undocumented in marine fishes, can significantly influence the probability of recovery and persistence of collapsed populations by affecting their ability to respond to natural and anthropogenic environmental change.
Dispersal of introduced house sparrows
Passer domesticus
: an experiment
Authors: Skjelseth Sigrun , Ringsby Thor Harald , Tufto Jarle , Jensen Henrik , Sæther Bernt-Erik
Published: May 2007

An important issue concerning the introduction of non-indigenous organisms into local populations is the potential of the introduced individuals to spread and interfere both demographically and genetically with the local population. Accordingly, the potential of spatial dispersal among introduced individuals compared with local individuals is a key parameter to understand the spatial and temporal dynamics of populations after an introduction event. In addition, if the variance in dispersal rate and distance is linked to individual characteristics, this may further affect the population dynamics. We conducted a large-scale experiment where we introduced 123 house sparrows from a distant population into 18 local populations without changing population density or sex ratio. Introduced individuals dispersed more frequently and over longer distances than residents. Furthermore, females had higher probability of dispersal than males. In females, there was also a positive relationship between the wing length and the probability of dispersal and dispersal distance. These results suggest that the distribution and frequency of introduced individuals may be predicted by their sex ratio as well as their phenotypic characteristics.
Stable isotope and pen feeding trial studies confirm the value of horseshoe crab Limulus polyphemus eggs to spring migrant shorebirds in Delaware Bay
Authors: Michael Haramis G. , A. Link William , C. Osenton Peter , B. Carter David , G. Weber Richard , A. Clark Nigel , A. Teece Mark , S. Mizrahi David
Published: May 2007

We used stable isotope (SI) methods in combination with pen feeding trials to determine the importance of eggs of the Atlantic horseshoe crab Limulus polyphemus to migratory fattening of red knots Calidris canutus rufa and ruddy turnstones Arenaria interpres morinella during spring stopover in Delaware Bay. By manifesting measurable fractionation (ca +3‰) and rapid turnover, blood plasma δ15 nitrogen proved a functional marker for SI diet tracking during the short 3‐week stopover. Blood samples from free‐ranging knots (3 data sets) and turnstones (1 data set) produced similar convergence of plasma δ15N signatures with increasing body mass that indicated highly similar diets. Asymptotes deviated slightly (0.3‰ to 0.7‰) from that of captive shorebirds fed a diet of only crab eggs during stopover, thus confirming a strong crab egg‐shorebird linkage. The plasma δ15N crab‐egg diet asymptote was enriched ca +4.5‰ and therefore readily discriminated from that of either blue mussels Mytilus edulis or coquina clams Donax variabilis, the most likely alternative prey of knots in Delaware Bay. Crab eggs were highly palatable to captive knots and turnstones which achieved rates of mass gain (3–11 g/d) comparable to that of free‐ranging birds. Peak consumption rates during hyperphagic events were 23,940 and 19,360 eggs/bird/d, respectively. The empirical conversions of eggs consumed to body mass gained (5,017 eggs/g for knots and 4,320 eggs/g for turnstones) indicate the large quantities of crab eggs required for the maintenance of these shorebird populations during stopover.
Establishment of a novel melanoma cell line SMYM‐PRGP showing cytogenetic and biological characteristics of the radial growth phase of acral melanomas
Authors: Murata Hiroshi , Ashida Atsuko , Takata Minoru , Yamaura Maki , Bastian Boris C. , Saida Toshiaki
Published: May 2007

We established a novel melanoma cell line, SMYM‐PRGP, which was non‐tumorigenic in vivo, from an acral melanoma in radial growth phase under a low‐oxygen environment. SMYM‐PRGP was wild‐type for known mutation sites in the BRAF and NRAS genes, and showed focal amplification of the human telomerase reverse transcriptase and cyclin D1 genes as well as the fibroblast growth factor‐3 and fibroblast growth factor‐4 genes. Neither mutation nor copy number loss of the CDKN2A gene was observed. The p16INK4A protein was expressed at a level equal to that in normal melanocytes. Among the various melanocyte growth factors added to the culture of SMYM‐PRGP cells, endothelin‐1 was the strongest growth stimulator, the effect of which was significantly augmented by the addition of calcium chloride. The growth stimulatory effect of endothelin‐1 was shown to be mediated via the endothelin B receptor. The protein level of cyclin D1 in SMYM‐PRGP cells was approximately 10 times higher than that in normal melanocytes. Although the stimulation with endothelin‐1 plus calcium chloride increased cyclin D1 protein levels after 4–6 h, the level of phosphorylated retinoblastoma protein did not increase, suggesting that overexpression of cyclin D1 protein may have little effect on cell cycle progression but rather act as a pro‐survival factor. SMYM‐PRGP is an excellent tool for investigating the development and progression of acral melanoma. (Cancer Sci 2007; 98: 958–963)
Cytomorphological and immunocytochemical study of non‐Hodgkin's lymphoma in pleural effusion and ascitic fluid
Authors: Das D. K. , Al‐Juwaiser A. , George S. S. , Francis I. M. , Sathar S. S. , Sheikh Z. A. , Shaheen A. , Pathan S. K. , Haji B. E. , George J. , Kapila K.
Published: May 2007

Introduction:  Non‐Hodgkin's lymphoma (NHL) is often complicated by pleural effusion and ascites. The present study is an attempt to categorize the lymphomatous effusions according to the WHO classification, using archival material.

Methods:  May‐Grünwald–Giemsa and Papanicolaou‐stained smears of 31 lymphomatous effusion specimens were reviewed. Of these, detailed cytological assessment was done on 12 pleural effusions and ten ascitic fluid specimens from 22 patients using the WHO lymphoma classification system. Immunocytochemical studies were performed in 21 specimens.

Results:  Based on cytomorphological features, the 22 lymphomatous effusion specimens were categorized into lymphoplasmacytoid lymphoma (1), follicle centre cell (FCC) grade‐1 (centrocytic) lymphoma (3), FCC grade‐2 (centrocytic–centroblastic) lymphoma (3), FCC grade‐3 (centroblastic) lymphoma (4), large cell immunoblastic lymphoma (4), lymphoblastic lymphoma (2), anaplastic large cell lymphoma (3) and miscellaneous types (2). Immunocytochemically, the lymphoma cells were T‐cell (positive for CD3) and B‐cell type (CD20 positive) in five and six cases respectively.

Conclusion:  Cytological examination of pleural effusion and ascitic fluid samples, supported by immunocytochemical studies, may be useful for the classification of lymphomas under the WHO system.
Volcanic explosive eruptions of the Vesuvio decrease tree‐ring growth but not photosynthetic rates in the surrounding forests
Authors: BATTIPAGLIA GIOVANNA , CHERUBINI PAOLO , SAURER MATTHIAS , SIEGWOLF ROLF T. W. , STRUMIA SANDRO , FRANCESCA COTRUFO M.
Published: May 2007

Volcanic eruptions impact the global and the hemispheric climate, but it is still unknown how and to what degree they force the climate system and in particular the global carbon cycle. In this paper, the relationships between individual eruptions (reconstructed for the past using written records), tree primary productivity (estimated using ring widths), photosynthetic rate and stomatal conductance (assessed by carbon and oxygen isotope data) are investigated, to understand the impact of volcanic eruptions on net primary production. Data from a mixed stand ofFagus sylvaticaL. andAcer pseudoplatanusL. located in the area of the Vesuvio volcanic complex (Southern Italy) showed a significant decrease in ring width following each eruption. Isotope analyses indicate a change in climatic conditions after such events. Specifically, the lower oxygen isotope ratio in the tree‐ring cellulose strongly suggests an increase in relative humidity and a decrease in temperature, with the latter resulting in a strong limitation to tree‐ring growth. The carbon isotope ratio was only moderately but not significantly reduced in the years of volcanic eruption, suggesting no major changes in C fixation rates. This work is a case study on the effects of volcanic eruptions resulting in strong climatic changes on the local scale. This is an opportunity to explore the process and causal relationships between climatic changes and the response of the vegetation. Thus, we propose here a realistic model scenario, from which we can extrapolate to global scales and improve our interpretations of results of global studies.
Cooler temperatures increase sensitivity to ultraviolet B radiation in embryos and larvae of the frog Limnodynastes peronii
Authors: Van UITREGT VINCENT O. , WILSON ROBBIE S. , FRANKLIN CRAIG E.
Published: May 2007

Recent studies suggest that complex interacting processes are driving global amphibian declines. Increased ultraviolet B (UVB) radiation in the solar spectrum associated with ozone depletion has been implicated in declines, and evidence suggests that the effects of UVB radiation on amphibians may be greater at cooler temperatures. We tested the thermal sensitivity of UVB effects on amphibians in a controlled factorial experiment using the striped marsh frog, Limnodynastes peronii as a model species. We compared survival, growth and locomotor performance of embryonic and larval L. peronii reared under low and high UVB exposures at both 20 and 30 °C. Embryonic and larval L. peronii proved extremely sensitive to UVB damage and exhibited greater sensitivity at 20 °C compared with 30 °C. Embryonic survival to Gosner stage 25 was unaffected by UVB exposure at 30 °C, but at 20 °C survival was reduced to 52% under high UVB. Larval survival exhibited a similar trend. At 20 °C, all tadpoles survived under low UVB, whereas under high UVB there was 100% mortality after 15 days of exposure. At 30 °C, 86% survived under low UVB, but only 46% survived under high UVB. Sublethal effects such as, embryonic malformation, retarded larval growth and reduced larval swimming performance were also greater at 20 °C compared with 30 °C. Our results strongly indicate that UVB damage in amphibians is markedly increased at cooler temperatures. Thus, populations of UVB sensitive species occurring at cold climates may be at greater risk of declines due to increased solar UVB radiation.
Differential regulation of lipopolysaccharide and Gram‐positive bacteria induced cytokine and chemokine production in macrophages by Gαi proteins
Authors: Fan Hongkuan , Williams David L. , Zingarelli Basilia , Breuel Kevin F. , Teti Giuseppe , Tempel George E. , Spicher Karsten , Boulay Guylain , Birnbaumer Lutz , Halushka Perry V. , Cook James A.
Published: May 2007

Heterotrimeric Gi proteins play a role in signalling activated by lipopolysaccharide (LPS), Staphylococcus aureus (SA) and group B streptococci (GBS), leading to production of inflammatory mediators. We hypothesized that genetic deletion of Gi proteins would alter cytokine and chemokine production induced by LPS, SA and GBS stimulation. LPS‐induced, heat‐killed SA‐induced and heat‐killed GBS‐induced cytokine and chemokine production in peritoneal macrophages from wild‐type (WT), Gαi2–/– or Gαi1/3–/– mice were investigated. LPS induced production of tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6), IL‐10 and interferon‐γ‐inducible protein‐10 (IP‐10); SA induced TNF‐α, and IL‐1β production; and GBS induced TNF‐α, IL‐6, IL‐1β, macrophage inflammatory protein‐1α (MIP‐1α) and keratinocyte chemoattract (KC) production were all decreased (P < 0·05) in Gαi2–/– or Gαi1/3–/– mice compared with WT mice. In contrast to the role of Gi proteins as a positive regulator of mediators, LPS‐induced production of MIP‐1α and granulocyte–macrophage colony‐stimulating factor (GM‐CSF) were increased in macrophages from Gαi1/3–/– mice, and SA‐induced MIP‐1α production was increased in both groups of Gαi protein‐depleted mice. LPS‐induced production of KC and IL‐1β, SA‐induced production of GM‐CSF, KC and IP‐10, and GBS‐induced production of IL‐10, GM‐CSF and IP‐10 were unchanged in macrophages from Gαi2–/– or Gαi1/3–/– mice compared with WT mice. These data suggest that Gi2 and Gi1/3 proteins are both involved and differentially regulate murine inflammatory cytokine and chemokine production in response to both LPS and Gram‐positive microbial stimuli.
Predictors of serum testosterone and DHEAS in African‐American men
Authors: Haren Matthew T. , Banks William A. , Perry III H. M. , Patrick Ping , Malmstrom Theodore K. , Miller Douglas K. , Morley John E.
Published: May 2007

There are few reported data on biochemical and functional correlates of androgen levels in African‐American men. This study aimed at reporting physical and biochemical correlates of serum total testosterone (total T), bioavailable testosterone (BT) and dehydroepiandrosterone‐sulphate (DHEAS) levels in community‐dwelling, African‐American men aged 50–65 years. Home‐based physical examinations and health status questionnaires were administered to randomly sampled men. Body composition (dual‐energy X‐ray absorptiometry), lower limb and hand‐grip muscle strength, and neuropsychological functions were assessed. Levels of serum total T, BT, DHEAS, oestradiol (E2), adiponectin, leptin, triglycerides and glucose were measured. Multiple linear regression models were constructed to identify factors independently associated with androgen levels. DHEAS levels declined from age 50 to 65 years (p < 0.0001), but total T and BT levels remained constant. Independent of other associated factors, higher total T levels were associated with lower serum triglyceride levels (β = −0.142, p = 0.049); higher BT was associated with better performance on the trail‐making tests (TMT‐B:TMT‐A ratio: β = −0.118, p = 0.024) and higher DHEAS levels were associated with lower adiponectin (β = −0.293, p = 0.047) and higher mini‐mental state examination (MMSE) score (β = 0.098, p = 0.008). Multiple regression models predicted 21, 18 and 29% of variance in total T, BT and DHEAS, respectively. Higher total T levels were associated with serum metabolic markers, particularly lower triglycerides, whereas higher BT was associated with better cognitive and muscle function and DHEAS with lower adiponectin and higher MMSE scores.
The frequency of undescended testis from birth to adulthood: a review
Authors: Sijstermans K. , Hack W. W. M. , Meijer R. W. , Voort‐Doedens L. M. van der
Published: May 2007

We performed a systematic review and critique of the literature on the frequency of undescended testis (UDT) among boys from birth to adolescence. Special attention was given to whether previous testicular position was taken into account to distinguish between congenital and acquired UDT. We searched Medline, Embase, Cinahl and the Cochrane Library. Any study reporting on the frequency of UDT was included. Study population age, number of boys studied, period of examination, primary examiner, area of study, study design, ethnicity, definitions used and previous testicular position were analysed. A total of 46 studies met the inclusion criteria. Twenty‐three of the 46 (50%) studies involved newborns. Definitions were described in half of the studies; however, the definitions used were heterogeneous. Previous testis position was described in 11% (5/46) of the studies. At birth, in term and/or birth weight >2.5 kg infants, the UDT rate ranged from 1.0 to 4.6%, and in premature and/or birth weight <2.5 kg infants from 1.1 to 45.3%. At the age of 1 year UDT in term and/or birth weight >2.5 kg infants was seen in 1.0–1.5%, at 6 years in 0.0–2.6%, at 11 years in 0.0–6.6% and at 15 years in 1.6–2.2% of boys. The frequency of UDT shows variable figures in the literature. The actual frequency of acquired UDT essentially remains unclear because of the shortage of studies performed at an older age, and of studies reporting on previous testicular position.
A regional study of Holocene climate change and human occupation in Peruvian Amazonia
Authors: Bush M. B. , Silman M. R. , Listopad C. M. C. S.
Published: May 2007

Aim  To investigate the influence of Holocene climatic and human‐induced changes on a region of high biodiversity in southern Peruvian Amazonia.

Location  Four palaeoecological records from separate lakes within a lake district close to the modern city of Puerto Maldonado, Peru.

Results  The lakes provide a palaeoecological record spanning the last 8200 years. A mid‐Holocene dry event is documented in all of the records that extend back > 6000 years. The dry event appears to have lasted from c. 7200 yr bp until c. 3300 yr bp. The onset of wetter conditions coincides with the formation of the youngest of the four lakes. The earliest occupation of these sites is inferred from the presence of charcoal at 7200 yr bp, and the first crop pollen is found at 3630 yr bp. Lakes that were regularly occupied were colonized soon after they formed. A reduction in charcoal concentration and the absence of crop pollen after c. 500 bp in all lakes is consistent with site abandonment following conquest.

Main conclusions  The mid‐Holocene dry event is suggested to be part of a time‐transgressive drying that tracked from north to south in both the Andes and the Amazon lowlands. The last millennium may represent the period of highest sustained lake levels within the Holocene. The proximity of the four lakes allows a landscape‐scale analysis of the spatial extent of human disturbance centred on a known site of human occupation and reveals the highly localized nature of pre‐Columbian anthropogenic disturbance in Amazonian landscapes. Inferences regarding widespread pre‐Columbian landscape modification by indigenous peoples must take into account key site attributes, such as seasonality and proximity to rivers.
Teacher guidelines for cross‐national virtual communities in primary education
Authors: Ligorio M.B. , Van der Meijden H.
Published: May 2007

Abstract  The purpose of this study is to provide guidelines for teachers to carry out cross‐national educational projects in schools through the introduction of virtual environments as a means of reshaping classroom‐based activities. The theoretical foundations of the study are rooted in computer supported collaborative learning and the community of learners model. The case of Euroland is discussed as a successful example of mixing a face‐to‐face community with a larger community, which populates a virtual space. The virtual space used in this project features two pieces of software – a discussion forum and a three‐dimensional virtual world – each of which are considered to be complementary. Students (ranging from 9 to 14 years old) from seven schools located in two European countries (Italy and The Netherlands) participated in the project. The development of Euroland took place across three temporal phases. These are described through four indicators, considered as relevant practices that are easily observed. The first indicator relates to the use of tools embedded within the virtual environments, very exploratory in the first phase, becoming more and more integrated in the phases that follow. The second indicator relates to the quality of interaction with partners at a distance, initially based on a simple representation and awareness of them, ultimately becoming more precise and detailed. The third indicator relates to the development of a sense of belonging to a community, initially limited to the in‐the‐classroom community and then progressively extended to the virtual community as indicated by the increased amount of time devoted to navigation and online activities and an increased use in quoting instances of activities in online life. The final indicator refers more specifically to the range of educational strategies' teachers should use in such contexts. As results of the analysis of how the indicators are set during each phase, teachers' guidelines are established. Teacher guidelines are given by differentiating between in‐classroom and online contexts with the aim of obtaining the best possible results in accomplishing a project‐like Euroland.
Differences in Lepeophtheirus salmonis abundance levels on Atlantic salmon farms in the Broughton Archipelago, British Columbia, Canada
Authors: Saksida S , Karreman G A , Constantine J , Donald A
Published: May 2007

Sea lice data collected from Atlantic salmon farms in the Broughton Archipelago between 2003 and 2005 were examined for inter‐regional differences in mobile Lepeophtheirus salmonis (Krøyer) abundance using the generalized linear model procedure. Factors such as age of the salmon populations, location of farms and time of year had a significant effect on the abundance of the mobile stages of L. salmonis whereas water temperature and salinity did not. Separate evaluation of SLICE® treatment data found no significant difference in treatment frequency among the areas but did show that there were significantly lower numbers of farm treatments during the summer months when compared with other seasons. The role of environment and wild fish in influencing sea lice abundance on the farmed salmon is discussed. The findings suggest that effective management programmes for sea lice should not only be based on geographical location but should take into account other factors which could influence lice abundance levels.
Evaluation of lethal and non‐lethal sampling methods for the detection of white sturgeon iridovirus infection in white sturgeon, Acipenser transmontanus (Richardson)
Authors: Drennan J D , LaPatra S E , Samson C A , Ireland S , Eversman K F , Cain K D
Published: May 2007

Pectoral fin tissue of white sturgeon was investigated as a potential non‐lethal sample source for the detection of white sturgeon iridovirus (WSIV) infection. Histopathology and polymerase chain reaction (PCR) results using fin tissue were compared with the standard lethal histopathology sampling method that utilizes head tissue. Tissues for each of the three sampling methods were collected weekly for 8 weeks from individual sturgeon undergoing an experimental cohabitation challenge with fish infected with the Abernathy isolate of WSIV. Non‐lethal fin histopathological evaluation did not reveal infection during the first 3 weeks of sampling, while non‐lethal PCR and the lethal method were variable. However, all three sampling methods were equally capable of identifying infection from 4 to 8 weeks post‐exposure. Of the survivors tested, all were negative by PCR and the lethal method, and only one fish was identified as being positive by non‐lethal fin histopathology. In another experiment, all three sampling methods were applied to asymptomatic WSIV carriers in a case study conducted at the Kootenai Tribal Sturgeon Conservation Hatchery. Results showed that both lethal and non‐lethal fin histopathology were equally effective in detecting infection, but PCR was unable to identify this strain of WSIV. Depending on the virus isolate, these results suggest that non‐lethal sampling of fin tissue (histopathology or PCR) is comparable with the lethal sampling method at identifying WSIV infection once infection is established, and under certain circumstances may provide an alternative to lethal sampling.
The pathogenic helminth parasites of eels
Authors: Kennedy C R
Published: May 2007

Although 63 and 55 species of helminths have been reported from each species of Atlantic eel and from 29 to 19 for each species of Pacific eel only the monogeneans Pseudodactylogyrus bini and P. anguillae and the nematode Anguillicola crassus, originally specific to species of Pacific eels, can be considered serious pathogens. None of the three are normally pathogenic to their preferred natural eel host species in the wild. Pseudodactylogyrus spp. only cause serious local gill damage when present on a host in large numbers under optimal conditions that facilitate transmission. This is the case in eel aquaculture, where infections can be controlled by drugs. Anguillicola crassus is only pathogenic to Anguilla anguilla and A. rostrata when Atlantic eels are introduced to the far east or when the parasites have been introduced to Europe. Here the parasite life cycle differs in that A. crassus can infect a wide range of intermediate hosts, employ paratenic hosts and survive as larvae for months in the swimbladder wall. This makes it an excellent colonizer. Its major pathogenic effects on eels result from haemorrhaging in, and thickening of, the swimbladder wall. It reduces the oxygen concentration in the swimbladder, reducing its ability to function as a hydrostatic organ, and increases the stress response of eels. In shallow lakes at warm temperatures this can result in mass mortalities. It is also feared that the parasite affects the ability of eels to migrate to the Sargasso Sea and so contributes to the decline in eel populations. Control by drug treatment is possible in culture, but not in the wild.
Long‐term effects of translocation and release numbers on fine‐scale population structure among coho salmon (Oncorhynchus kisutch)
Authors: ELDRIDGE WILLIAM H. , NAISH KERRY A.
Published: May 2007

Management actions, such as translocations, reintroductions and supportive breeding, can have both negative and positive effects on population recovery. Several studies have examined the incidence of introgression following such actions, but few studies have explored the effect of release numbers on gene flow between closely related recipient populations. We examined population structure of coho salmon in Puget Sound (Washington State, USA) to evaluate the relationship between the number of individuals transferred between rivers, and the number released within rivers, on inter‐ and intrariver population divergence. Eleven microsatellite loci were surveyed in 23 hatchery and wild samples collected from 11 rivers within and one hatchery outside Puget Sound. Pairwise genetic divergences between most populations were significant, but the population structure could not be explained by an isolation‐by‐distance model (Mantel test, P > 0.05). In contrast, we detected significant hatchery influence on population structure. The numbers of fish transferred among rivers between 1952 and 2004 was negatively correlated with differentiation between rivers (partial Mantel test, P = 0.005) but not within rivers (t‐test, P = 0.41). Number of fish released from hatcheries that collect broodstock locally was negatively correlated with population structure within rivers (t‐test P = 0.002), and between nearby rivers (partial Mantel P = 0.04). Our results indicate that the population structure can, to some degree, be altered by the number of individuals transferred and by local release number of individuals in ongoing artificial propagation programs. The findings presented here emphasize the need to control the number of individuals that are either inadvertently introduced, or are deliberately released under conservation scenarios.
Effects of recent population bottlenecks on reconstructing the demographic history of prairie‐chickens
Authors: JOHNSON JEFF A. , DUNN PETER O. , BOUZAT JUAN L.
Published: May 2007

Current methods of DNA sequence analysis attempt to reconstruct historical patterns of population structure and growth from contemporary samples. However, these techniques may be influenced by recent population bottlenecks, which have the potential to eliminate lineages that reveal past changes in demography. One way to examine the performance of these demographic methods is to compare samples from populations before and after recent bottlenecks. We compared estimates of demographic history from populations of greater prairie‐chickens (Tympanuchus cupido) before and after recent bottlenecks using four common methods (nested clade analysis [NCA], Tajima'sD, mismatch distribution, andmdiv). We found that NCA did not perform well in the presence of bottleneck events, although it did recover some genetic signals associated with increased isolation and the extinction of intermediate populations. The majority of estimates for Tajima'sD, including those from bottlenecked populations, were not significantly different from zero, suggesting our data conformed to neutral expectations. In contrast, mismatch distributions including the raggedness index were more likely to identify recently bottlenecked populations with this data set. Estimates of population mutation rate (θ), population divergence time (t), and time to the most recent common ancestor (TMRCA) frommdivwere similar before and after bottlenecks; however, estimates of gene flow (M) were significantly lower in a few cases following a bottleneck. These results suggest that caution should be used when assessing demographic history from contemporary data sets, as recently fragmented and bottlenecked populations may have lost lineages that affect inferences of their demographic history.
Sex‐biased dispersal in western lowland gorillas (Gorilla gorilla gorilla)
Authors: DOUADI MELANIE I. , GATTI SYLVAIN , LEVRERO FLORENCE , DUHAMEL GAËTAN , BERMEJO MAGDALENA , VALLET DOMINIQUE , MENARD NELLY , PETIT ERIC J.
Published: May 2007

We explored two hypotheses related to potential differences between sexes in dispersal behaviour in western lowland gorillas (Gorilla gorilla gorilla). Direct observations suggest that immature females have more opportunities to move between breeding groups than immature males. The distribution of kin dyadic relationships within and between groups does not, however, support this hypothesis. At larger geographical scales, dispersal is likely to be easier for males than females because of the solitary phase most blackbacks experience before founding their own breeding group. However, previous work indicates that males settle preferentially close to male kin. By specifically tracing female and male lineages with mitochondrial and Y‐chromosomal genetic markers, we found that male gorillas in the 6000 km2area we surveyed form a single population whereas females are restricted to the individual sites we sampled and do not freely move around this area. These differences are more correctly described as differences in dispersal distances, rather than differences in dispersal rates between sexes (both sexes emigrate from their natal group in this species). Differences in resource competition and dispersal costs between female and male gorillas are compatible with the observed pattern, but more work is needed to understand if these ultimate causes are responsible for sex‐biased dispersal distances in western lowland gorillas.
Phylogeography of the invasive seaweed Asparagopsis (Bonnemaisoniales, Rhodophyta) reveals cryptic diversity
Authors: ANDREAKIS NIKOS , PROCACCINI GABRIELE , MAGGS CHRISTINE , KOOISTRA WIEBE H. C. F.
Published: May 2007

The rhodophyte seaweed Asparagopsis armata Harvey is distributed in the northern and southern temperate zones, and its congener Asparagopsis taxiformis (Delile) Trevisan abounds throughout the tropics and subtropics. Here, we determine intraspecific phylogeographic patterns to compare potential causes of the disjunctions in the distributions of both species. We obtained specimens throughout their ranges and inferred phylogenies from the hypervariable domains D1‐D3 of the nuclear rDNA LSU, the plastid spacer between the large and small subunits of RuBisCo and the mitochondrial cox 2–3 intergenic spacer. The cox spacer acquired base changes the fastest and the RuBisCo spacer the slowest. Median‐joining networks inferred from the sequences revealed the absence of phylogeographic structure in the introduced range of A. armata, corroborating the species’ reported recent introduction. A. taxiformis consisted of three nuclear, three plastid and four mitochondrial genetically distinct, lineages (1–4). Mitochondrial lineage 3 is found in the western Atlantic, the Canary Islands and the eastern Mediterranean. Mitochondrial lineages 1, 2, and 4 occur in the Indo‐Pacific, but one of them (lineage 2) is also found in the central Mediterranean and southern Portugal. Phylogeographic results suggest separation of Atlantic and Indo‐Pacific lineages resulted from the emergence of the Isthmus of Panama, as well as from dispersal events postdating the closure event, such as the invasion of the Mediterranean Sea by mitochondrial lineages 2 and 3. Molecular clock estimates using the Panama closure event as a calibration for the split of lineages 3 and 4 suggest that A. taxiformis diverged into two main cryptic species (1 + 2 and 3 + 4) about 3.2–5.5 million years ago (Ma), and that the separation of the mitochondrial lineages 1 and 2 occurred 1–2.3 Ma.
Teratocytes growth pattern reflects host suitability in a host–parasitoid assemblage
Authors: FIRLEJ ANNABELLE , LUCAS ÉRIC , CODERRE DANIEL , BOIVIN GUY
Published: May 2007

Abstract In some parasitoid species, the serosa membrane breaks apart at hatching and produces teratocyte cells that assume various functions (immunossupression, secretion and nutrition) mediating host–parasitoid relationships. Teratocyte growth pattern may thus reflect the host suitability for a parasitoid. The teratocyte growth pattern (increase in size and number of teratocytes as a function of time) is studied and used as an indirect measure of fitness to compare the development of the endoparasitoid Dinocampus coccinellae in a marginal host, the coccinellid Harmonia axyridis, and in a suitable host, Coleomegilla maculata. Indirect measures of fitness recorded in both host species confirm that C. maculata is a suitable host for D. coccinellae contrary to the marginal host H. axyridis. According to regression analysis, teratocyte numbers decrease linearly whereas teratocyte size increases linearly with time in the suitable host C. maculata (larvae or adults). In the marginal host, parasitism occurs only in the larval stage where a delay in the parasitoid larval development is observed. Increase in teratocyte size is also highly variable. The teratocyte growth pattern of the parasitoid in the marginal host does not follow the linear model found in the suitable host. Teratocyte growth pattern may be a useful criterion to evaluate host‐suitability and host range of parasitoids.
Responses to olfactory and visual cues by over‐wintered and summer generations of the pollen beetle, Meligethes aeneus
Authors: JÖNSSON MARTIN , ROSDAHL KRISTINA , ANDERSON PETER
Published: May 2007

Abstract Behavioural responses to odours of oilseed rape in bud and flower stage and to green and yellow colours are studied for the two main phenological stages of pollen beetles, Meligethes aeneus, a major pest of oilseed rape, Brassica napus. Over‐wintered individuals oviposit in buds of oilseed rape. Adults of the new generation (i.e. the summer generation) feed on flowers of different plant species before over wintering. In olfactometer experiments, the over‐wintered beetles display a higher preference for odour of oilseed rape at the bud stage compared with the summer generation, both with and without colour stimuli. Flower odours are preferred in combination with yellow colour. Colour stimuli presented alone do not affect the behaviour. The summer generation beetles respond to both bud and flower odour. Adding colour stimuli changes the summer generations preference towards yellow and flower odour.
Cuticular lipid mass and desiccation rates in Glossina pallidipes: interpopulation variation
Authors: JURENKA RUSSELL , TERBLANCHE JOHN S. , JACO KLOK C. , CHOWN STEVEN L. , KRAFSUR ELLIOT S.
Published: May 2007

Abstract Tsetse flies, Glossina pallidipes (Diptera: Glossinidae) are said to have strong dispersal tendencies. Gene flow among these populations is estimated to be the theoretical equivalent of no more than one or two reproducing flies per generation, thereby raising the hypothesis of local regimes of natural selection. Flies were sampled from four environmentally diverse locations in Kenya to determine whether populations are homogeneous in desiccation tolerance and cuticular lipids. Cuticular hydrocarbon fractions known to act as sex pheromones do not differ among populations, thereby eliminating sexual selection as an isolating mechanism. Cuticular lipid quantities vary among populations and are not correlated with prevailing temperatures, humidities, and normalized density vegetation indices. Females demonstrate a stronger correlation than males between cuticular lipid mass and body weight. Desiccation rates also vary among populations, but are not correlated with the amounts of cuticular lipid. Chemical analysis of cuticular hydrocarbons by gas chromatography–mass spectroscopy shows that one of the four populations has more 11,15‐ and 11,21‐dimethyl‐31 hydrocarbon on females. These results are discussed in the context of population differences and estimates of gene flow.
Temporal dynamics of the encapsulation response towards a synthetic immune challenge in Acheta domesticus
Authors: RYDER JONATHAN J.
Published: May 2007

Abstract Researchers interested in insect ‘ecological immunology’ often quantify variation among individuals in the capacity to produce an immune response by challenging the immune system with a synthetic implant. Many studies focus on the encapsulation response in particular, because it requires the coordination of different cellular and humoral factors. However, most encapsulation assays are based on a single assay period, in part because the assay is destructive, such that the response cannot be measured repeatedly in the same individual. This approach may be problematic. For example, if the time‐course of the response is complex, an arbitrarily chosen assay period may fail to capture the most biologically relevant parameters of the response. In the present study, the time‐course of the encapsulation response towards a synthetic, nylon implant is investigated over a 5‐day period, using Acheta domesticus as a model host. Encapsulation is quantified at intervals by randomly allocating crickets to different time‐points. The most rapid period of capsule development appears to occur during the first 6‐h period. Subsequent increases in capsule size can only be confirmed during the latter stages of the assay period, when there is also a significant increase in haemocyte density. The results indicate that, in any given system, the assay period should ideally be based on preliminary data quantifying the time‐course of the response. Such data encourage clearer conclusions regarding the biological meaning of the assay and will increase relevance for real‐host parasite systems, in which temporal dynamics can be highly variable.