bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of Broadcast World News Web Pages: Al Jazeera English, BBC, CBS, and CNN
Authors: Loomis Kenneth D.
Published: July 2009

Officials of an English language version of the controversial television network Al Jazeera have been seeking distribution of it outside the Middle East. Those officials at Al Jazeera English (AJE) claim it's different from both its Middle Eastern namesake and the Western networks against which they're seeking to have it compete. A content analysis of the World news Web pages of Al Jazeera English, the BBC, CBS, and CNN compared features such as use of hyperlinks, videos, and interactive elements as well as story selection and sources quoted. All four networks covered essentially the same stories and quoted similar sources. Although AJE had the fewest number of stories with a positive tone toward the United States, its content was comparable to the other networks' content in terms of treatment of the United States and use of emotionally charged language. AJE was found to be similar enough to the other networks that its unique perspective was difficult to identify.
A ZYG-12–dynein interaction at the nuclear envelope defines cytoskeletal architecture in the C. elegans gonad
Authors: Zhou Kang , Rolls Melissa M. , Hall David H. , Malone Christian J. , Hanna-Rose Wendy
Published: July 2009

Changes in cellular microtubule organization often accompany developmental progression. In the Caenorhabditis elegans embryo, the centrosome, which is attached to the nucleus via ZYG-12, organizes the microtubule network. In this study, we investigate ZYG-12 function and microtubule organization before embryo formation in the gonad. Surprisingly, ZYG-12 is dispensable for centrosome attachment in the germline. However, ZYG-12–mediated recruitment of dynein to the nuclear envelope is required to maintain microtubule organization, membrane architecture, and nuclear positioning within the syncytial gonad. We examined γ-tubulin localization and microtubule regrowth after depolymerization to identify sites of nucleation in germ cells. γ-Tubulin localizes to the plasma membrane in addition to the centrosome, and regrowth initiates at both sites. Because we do not observe organized microtubules around zyg-12(ct350) mutant nuclei with attached centrosomes, we propose that gonad architecture, including membrane and nuclear positioning, is determined by microtubule nucleation at the plasma membrane combined with tension on the microtubules by dynein anchored at the nucleus by ZYG-12.
Cohesin regulatesVSGmonoallelic expression in trypanosomes
Authors: Landeira David , Bart Jean-Mathieu , Van Tyne Daria , Navarro Miguel
Published: July 2009

Antigenic variation allows Trypanosoma brucei to evade the host immune response by switching the expression of 1 out of ∼15 telomeric variant surface glycoprotein (VSG) expression sites (ESs). VSG ES transcription is mediated by RNA polymerase I in a discrete nuclear site named the ES body (ESB). However, nothing is known about how the monoallelic VSG ES transcriptional state is maintained over generations. In this study, we show that during S and G2 phases and early mitosis, the active VSG ES locus remains associated with the single ESB and exhibits a delay in the separation of sister chromatids relative to control loci. This delay is dependent on the cohesin complex, as partial knockdown of cohesin subunits resulted in premature separation of sister chromatids of the active VSG ES. Cohesin depletion also prompted transcriptional switching from the active to previously inactive VSG ESs. Thus, in addition to maintaining sister chromatid cohesion during mitosis, the cohesin complex plays an essential role in the correct epigenetic inheritance of the active transcriptional VSG ES state.
Autophagy pathway intersects with HIV-1 biosynthesis and regulates viral yields in macrophages
Authors: Kyei George B. , Dinkins Christina , Davis Alexander S. , Roberts Esteban , Singh Sudha B. , Dong Chunsheng , Wu Li , Kominami Eiki , Ueno Takashi , Yamamoto Akitsugu , Federico Maurizio , Panganiban Antonito , Vergne Isabelle , Deretic Vojo
Published: July 2009

Autophagy is a cytoplasmic degradative pathway that can participate in biosynthetic processes, as in the yeast Cvt pathway, but is more commonly known for its functions in removing damaged or surplus organelles and macromolecular complexes. Here, we find that autophagy intersects with human immunodeficiency virus (HIV) biogenesis, mirroring the above dichotomy. Early, nondegradative stages of autophagy promoted HIV yields. HIV Gag-derived proteins colocalized and interacted with the autophagy factor LC3, and autophagy promoted productive Gag processing. Nevertheless, when autophagy progressed through maturation stages, HIV was degraded. This, however, does not occur, as the HIV protein Nef acts as an antiautophagic maturation factor through interactions with the autophagy regulatory factor Beclin 1, thus protecting HIV from degradation. The dual interaction of HIV with the autophagy pathway enhances viral yields by using the early stages while inhibiting the late stages of autophagy. The role of Nef in the latter process enhances yields of infectious HIV and may be of significance for progression to clinical AIDS.
Negative feedback control of the autoimmune response through antigen-induced differentiation of IL-10–secreting Th1 cells
Authors: Gabryšová Leona , Nicolson Kirsty S. , Streeter Heather B. , Verhagen Johan , Sabatos-Peyton Catherine A. , Morgan David J. , Wraith David C.
Published: July 2009

Regulation of the immune response to self- and foreign antigens is vitally important for limiting immune pathology associated with both infections and hypersensitivity conditions. Control of autoimmune conditions can be reinforced by tolerance induction with peptide epitopes, but the mechanism is not currently understood. Repetitive intranasal administration of soluble peptide induces peripheral tolerance in myelin basic protein (MBP)–specific TCR transgenic mice. This is characterized by the presence of anergic, interleukin (IL)-10–secreting CD4+ T cells with regulatory function (IL-10 T reg cells). The differentiation pathway of peptide-induced IL-10 T reg cells was investigated. CD4+ T cells became anergic after their second encounter with a high-affinity MBP peptide analogue. Loss of proliferative capacity correlated with a switch from the Th1-associated cytokines IL-2 and interferon (IFN)-γ to the regulatory cytokine IL-10. Nevertheless, IL-10 T reg cells retained the capacity to produce IFN-γ and concomitantly expressed T-bet, demonstrating their Th1 origin. IL-10 T reg cells suppressed dendritic cell maturation, prevented Th1 cell differentiation, and thereby created a negative feedback loop for Th1-driven immune pathology. These findings demonstrate that Th1 responses can be self-limiting in the context of peripheral tolerance to a self-antigen.
The external pore loop interacts with S6 and S3-S4 linker in domain 4 to assume an essential role in gating control and anticonvulsant action in the Na+ channel
Authors: Yang Ya-Chin , Hsieh Jui-Yi , Kuo Chung-Chin
Published: July 2009

Carbamazepine, phenytoin, and lamotrigine are widely prescribed anticonvulsants in neurological clinics. These drugs bind to the same receptor site, probably with the diphenyl motif in their structure, to inhibit the Na+ channel. However, the location of the drug receptor remains controversial. In this study, we demonstrate close proximity and potential interaction between an external aromatic residue (W1716 in the external pore loop) and an internal aromatic residue (F1764 in the pore-lining part of the sixth transmembrane segment, S6) of domain 4 (D4), both being closely related to anticonvulsant and/or local anesthetic binding to the Na+ channel. Double-mutant cycle analysis reveals significant cooperativity between the two phenyl residues for anticonvulsant binding. Concomitant F1764C mutation evidently decreases the susceptibility of W1716C to external Cd2+ and membrane-impermeable methanethiosulfonate reagents. Also, the W1716E/F1764R and G1715E/F1764R double mutations significantly alter the selectivity for Na+ over K+ and markedly shift the activation curve, respectively. W1716 and F1764 therefore very likely form a link connecting the outer and inner compartments of the Na+ channel pore (in addition to the selectivity filter). Anticonvulsants and local anesthetics may well traverse this “S6 recess” without trespassing on the selectivity filter. Furthermore, we found that Y1618K, a point mutation in the S3-4 linker (the extracellular extension of D4S4), significantly alters the consequences of carbamazepine binding to the Na+ channel. The effect of Y1618K mutation, however, is abolished by concomitant point mutations in the vicinity of Y1618, but not by those in the internally located inactivation machinery, supporting a direct local rather than a long-range allosteric action. Moreover, Y1618 could interact with D4 pore residues W1716 and L1719 to have a profound effect on both channel gating and anticonvulsant action. We conclude that there are direct interactions among the external S3-4 linker, the external pore loop, and the internal S6 segment in D4, making the external pore loop a pivotal point critically coordinating ion permeation, gating, and anticonvulsant binding in the Na+ channel.
The 9-methyl group of retinal is essential for rapid Meta II decay and phototransduction quenching in red cones
Authors: Estevez Maureen E. , Kolesnikov Alexander V. , Ala-Laurila Petri , Crouch Rosalie K. , Govardovskii Victor I. , Cornwall M. Carter
Published: July 2009

Cone photoreceptors of the vertebrate retina terminate their response to light much faster than rod photoreceptors. However, the molecular mechanisms underlying this rapid response termination in cones are poorly understood. The experiments presented here tested two related hypotheses: first, that the rapid decay rate of metarhodopsin (Meta) II in red-sensitive cones depends on interactions between the 9-methyl group of retinal and the opsin part of the pigment molecule, and second, that rapid Meta II decay is critical for rapid recovery from saturation of red-sensitive cones after exposure to bright light. Microspectrophotometric measurements of pigment photolysis, microfluorometric measurements of retinol production, and single-cell electrophysiological recordings of flash responses of salamander cones were performed to test these hypotheses. In all cases, cones were bleached and their visual pigment was regenerated with either 11-cis retinal or with 11-cis 9-demethyl retinal, an analogue of retinal lacking the 9-methyl group. Meta II decay was four to five times slower and subsequent retinol production was three to four times slower in red-sensitive cones lacking the 9-methyl group of retinal. This was accompanied by a significant slowing of the recovery from saturation in cones lacking the 9-methyl group after exposure to bright (>0.1% visual pigment photoactivated) but not dim light. A mathematical model of the turn-off process of phototransduction revealed that the slower recovery of photoresponse can be explained by slower Meta decay of 9-demethyl visual pigment. These results demonstrate that the 9-methyl group of retinal is required for steric chromophore–opsin interactions that favor both the rapid decay of Meta II and the rapid response recovery after exposure to bright light in red-sensitive cones.
Application of rate-equilibrium free energy relationship analysis to nonequilibrium ion channel gating mechanisms
Authors: Csanády László
Published: July 2009

Rate-equilibrium free energy relationship (REFER) analysis provides information on transition-state structures and has been applied to reveal the temporal sequence in which the different regions of an ion channel protein move during a closed–open conformational transition. To date, the theory used to interpret REFER relationships has been developed only for equilibrium mechanisms. Gating of most ion channels is an equilibrium process, but recently several ion channels have been identified to have retained nonequilibrium traits in their gating cycles, inherited from transporter-like ancestors. So far it has not been examined to what extent REFER analysis is applicable to such systems. By deriving the REFER relationships for a simple nonequilibrium mechanism, this paper addresses whether an equilibrium mechanism can be distinguished from a nonequilibrium one by the characteristics of their REFER plots, and whether information on the transition-state structures can be obtained from REFER plots for gating mechanisms that are known to be nonequilibrium cycles. The results show that REFER plots do not carry information on the equilibrium nature of the underlying gating mechanism. Both equilibrium and nonequilibrium mechanisms can result in linear or nonlinear REFER plots, and complementarity of REFER slopes for opening and closing transitions is a trivial feature true for any mechanism. Additionally, REFER analysis provides limited information about the transition-state structures for gating schemes that are known to be nonequilibrium cycles.
Direct multiplex sequencing (DMPS)—a novel method for targeted high-throughput sequencing of ancient and highly degraded DNA
Authors: Stiller Mathias , Knapp Michael , Stenzel Udo , Hofreiter Michael , Meyer Matthias
Published: July 2009

Although the emergence of high-throughput sequencing technologies has enabled whole-genome sequencing from extinct organisms, little progress has been made in accelerating targeted sequencing from highly degraded DNA. Here, we present a novel and highly sensitive method for targeted sequencing of ancient and degraded DNA, which couples multiplex PCR directly with sample barcoding and high-throughput sequencing. Using this approach, we obtained a 96% complete mitochondrial genome data set from 31 cave bear (Ursus spelaeus) samples using only two 454 Life Sciences (Roche) GS FLX runs. In contrast to previous studies relying only on short sequence fragments, the overlapping portion of our data comprises almost 10 kb of replicated mitochondrial genome sequence, allowing for the unambiguous differentiation of three major cave bear clades. Our method opens up the opportunity to simultaneously generate many kilobases of overlapping sequence data from large sets of difficult samples, such as museum specimens, medical collections, or forensic samples. Embedded in our approach, we present a new protocol for the construction of barcoded sequencing libraries, which is compatible with all current high-throughput technologies and can be performed entirely in plate setup.
A validation of intracellular pH measurements in fish exposed to hypercarbia: the effect of duration of tissue storage and efficacy of the metabolic inhibitor tissue homogenate method
Authors: Baker D.W. , May C. , Brauner C.J.
Published: July 2009

This study assessed the effect of tissue storage duration and accuracy of the metabolic inhibitor tissue homogenate (MITH) method on intracellular pH (pHi) values of tissues of white sturgeon Acipenser transmontanus during hypercarbia. No effect of storage in liquid nitrogen of up to 30 days was observed and MITH appears appropriate for measurement of pH in fish exposed to up to 10% CO2 (10000 Pa pCO2).
The effects of temperature and water concentration on the otolith incorporation of barium and manganese in black rockfish Sebastes melanops
Authors: Miller J.A.
Published: July 2009

Observations of multiple years of geographic variation in [Ba:Ca]otolith and [Mn:Ca]otolith in black rockfish Sebastes melanops prompted this study to examine the effects of temperature and water concentration on the otolith incorporation of Ba and Mn in this wholly marine species. The replicated experiment design consisted of two water temperatures (7·4 and 13·0° C) and four water concentrations of Ba:Ca and Mn:Ca. A positive, linear relationship between [Ba:Ca]water and [Ba:Ca]otolith was observed at both temperatures. A positive temperature effect was also observed with mean partition coefficients for Ba (DBa) greater in the 13° C than in the 7·4° C treatments (mean = 0·061 and 0·048, respectively). There was no relationship between [Mn:Ca]water and [Mn:Ca]otolith although a negative temperature effect was observed. Mean partition coefficients for Mn (DMn) were lower in the 13° C than in the 7·4° C treatments (mean = 0·027 and 0·036, respectively). The data presented support the assumption of a positive, linear relationship between water and otolith Metal:Ca concentrations for Ba:Ca but not for Mn:Ca. Thus, although indicative of residence in distinct water masses, observed variation in [Metal:Ca]otolith may not reflect variation in water concentration and can be affected by temperature. Caution should be applied in the interpretation of geographic variation of [Mn:Ca]otolith until the mechanisms regulating its incorporation are more fully understood.
Variation in prey selection of a piscivorous fish after the impoundment of a neotropical reservoir: prey size and type
Authors: Cantanhêde G. , Fugi R. , Hahn N.S.
Published: July 2009

The relative abundance and size of prey fish in the stomachs of the predator Acestrorhynchus pantaneiro were compared with those recorded in the field to estimate prey selection. Fish samples were taken monthly in the Manso Reservoir (State of Mato Grosso, Brazil) immediately after the impoundment, from March 2000 to February 2001 (period I) and from March 2003 to February 2004 (period II). In period I, the small relative dominance of the prey in the environment seemed to have lead to random foraging. In period II, however, when the forage fish Moenkhausia dichroura was dominant in the environment, the predator shifted its diet, foraging mainly on this prey. Species with short relative body depth were positively selected. The prey size classes between 30 and 49 mm, and 50 and 69 mm standard length (LS) were the most abundant in the environment. Small prey were predominantly selected by A. pantaneiro. Even when a given prey or prey size was predominant in the environment, A. pantaneiro was a selective predator and maintained its preferences associated to prey type and LS, although it consumed the most abundant resource.
Multi‐scale habitat selection by Murray cod Maccullochella peelii peelii in two lowland rivers
Authors: Koehn J.D.
Published: July 2009

This study provides information on habitat selection by the threatened Murray cod Maccullochella peelii peelii at two spatial scales in the Ovens and Murray Rivers in south‐eastern Australia. Both adult (>450 mm total length, LT) and age 0 year (<150 mm LT) M. p. peelii selected macro and microhabitats based on structural variables. At the macrohabitat scale, adults selected channel habitats in the river, floodplain channels at high floods and within Lake Mulwala, whereas the floodplain proper was avoided. Adult and age 0 year fish selected similar microhabitats regardless of site or hydrologic conditions, and selection was primarily influenced by the presence of higher loadings of structural woody habitat, higher c.v. in depth, more overhanging vegetation, shallower comparative depths and lower water velocities, closer to the bank. Age 0 year M. p. peelii appeared to select shallower habitats with greater amounts of structural woody habitat, closer to the river bank than adult fish.
Rapid fluctuation in infection levels of Neoheterobothrium hirame (Monogenea) in Japanese flounder Paralichthys olivaceus in the Joban area, Japan
Authors: Tomiyama T. , Watanabe M. , Kurita Y.
Published: July 2009

Neoheterobothrium hirame a haematophagous monogenean parasite on Japanese flounder Paralichthys olivaceus occurred at high prevalences (>70%) from 1999 to 2002 but thereafter declined and remained low (<20%) from 2003 to 2005 in the Joban area, Japan. In 2006, N. hirame became abundant again reaching a prevalence of 63%. Generalized linear models explained these rapid fluctuations in infection in relation to inshore water temperature, which affected the reproductive success of the parasite, and also the encounter rate between host and parasite through changes in their respective population densities. Severely anaemic fish were few, 2·4% even in 1999–2002 and 2006, suggesting that the effect of N. hirame infection on the P. olivaceus population was small in this area.
Some Atlantic cod Gadus morhua in the Baltic Sea visit hypoxic water briefly but often
Authors: Neuenfeldt S. , Andersen K.H. , Hinrichsen H.‐H.
Published: July 2009

Individual behaviour of Atlantic cod Gadus morhua in the presence of hypoxic water was measured in situ in the vertically stratified Bornholm Basin of the Baltic Sea. Considering all recaptured individuals, the use of hypoxic habitat was comparable to data derived by traditional survey data, but some G. morhua had migrated towards the centre of the c.100 m deep basin and spent about a third of their time at oxygen saturation <50%, possibly to forage on zoobenthos. Maximal residence time per visit in such hypoxic water was limited to a few hours, allowing for the digestion of consumed prey items in waters with sufficient dissolved oxygen.
The role of matrix metalloproteinases in the pathogenesis of abdominal wall hernias
Authors: Antoniou S. A. , Antoniou G. A. , Granderath F. A. , Simopoulos C.
Published: July 2009

Surgical treatment of abdominal wall hernia has been based for many decades on observational evidence, as the disease physiopathology was ambiguous. The long‐standing hypothesis of abnormal collagen metabolism as a causative factor of hernia disease seems to become substantiated by modern investigations, demonstrating a link between abnormal matrix metalloproteinase (MMP) expression and abdominal wall hernia. Current evidence suggests a strong correlation between MMP‐2 and direct inguinal hernia, while the role of this MMP in indirect, incisional and recurrent hernias has not been completely elucidated yet. Furthermore, MMP‐1 and MMP‐13 seem to be implicated in the physiopathology of recurrent hernia, while limited data link MMP‐1 also with incisional hernia formation. Despite the importance of MMP‐9 in wound healing mechanisms, its role in hernia pathogenesis has not been adequately investigated. Future research is expected to decipher the complex physiopathological mechanisms of hernia development and provide a basis for potential therapeutic applications.
Preparing to fledge: the adrenocortical and metabolic responses to stress in king penguin chicks
Authors: Corbel Hélène , Geiger Sylvie , Groscolas René
Published: July 2009

1. Modulating the adrenocortical response to stress and the corresponding mobilization of energy substrates allows animals to cope with energy‐demanding challenges imposed by ecological constraints. Whether such a modulation occurs during the fledging process of the king penguin chick (Aptenodytes patagonicus) was examined. In this seabird species, fledging is associated with moult completion, prolonged fasting and transition from terrestrial to marine life.

2. Specifically, it was tested whether the adrenocortical and metabolic responses to a capture‐handling stress i. depended on the developmental/moulting status of pre‐fledging birds, ii. were affected by their nutritional status, and iii. were inter‐related.

3. The adrenocortical response was 2–3 times lower at moult end and fledging than at the onset of moult, 1 month earlier. No direct evidence for a link between the adrenocortical response and moult‐related changes in circulating thyroid hormones was obtained.

4. At the onset of moult, chicks were in a nutritional status corresponding to phase I of fasting whereas those at moult end and fledging were in phase II of fasting. Thus, the adrenocortical response depended on nutritional status, being blunted during phase II when body proteins were spared and fat stores preferentially mobilized.

5. The metabolic response to acute stress was characterized by an increase in plasma glucose, NEFA and uric acid and by a decrease in plasma β‐hydroxybutyrate. Differences in this response between phase I and phase II fasting chicks suggest that the mix of energy substrates used to fuel energy demand during acute stress is the same as that routinely fuelling daily energy expenditure. We obtained no evidence for an interaction between corticosterone and metabolic responses.

6. Overall, the results suggest that, in pre‐fledging king penguin chicks, the nutritional rather than the developmental/moulting status modulates the adrenocortical and metabolic responses to an acute stress. The possible adaptive function of the blunting of these responses by the time of fledging is discussed.
Impact of insect defoliation on forest carbon balance as assessed with a canopy assimilation model
Authors: SCHÄFER KARINA V. R. , CLARK KENNETH L. , SKOWRONSKI NICHOLAS , HAMERLYNCK ERIK P.
Published: July 2009

Disturbances such as fire, hurricanes, and herbivory often result in the net release of CO2from forests to the atmosphere, but the magnitude of carbon (C) loss is poorly quantified and difficult to predict. Here, we investigate the carbon balance of an oak/pine forest in the New Jersey Pine Barrens using the Canopy Conductance Constrained Carbon Assimilation (4C‐A) model. The 4C‐A model utilizes whole‐tree sap‐flux and leaf‐level photosynthetic gas exchange measurements at distinct canopy levels to estimate canopy assimilation. After model parameterization, sensitivity analyses, and evaluation against eddy flux measurements made in 2006, the model was used to predict C assimilation for an undisturbed year in 2005, and in 2007 when the stand was completely defoliated for 2–3 weeks during an infestation of gypsy moths (Lymantria disparL.). Following defoliation, only 50% of the foliage reemerged in a second flush. In 2007, canopy net assimilation (AnC), as modeled with the 4C‐A, was reduced to approximately 75% ofAnCin 2006 (940 vs. 1240 g C m−2 a−1). Overall, net primary production (NPP) in 2007 was approximately 240 g C m−2 a−1(vs. 250 g C m−2 a−1in 2006), with 60% of NPP allocated to foliage production, a short‐term carbon pool. Woody biomass accumulation, a long‐term carbon pool, was reduced by 20% compared with the previous year (72 vs. 57 g C m−2 a−1in 2006 and 2007, respectively). The overall impact of the defoliation spanned 21% of upland forests (320 km2) in the New Jersey Pine Barrens, representing a significant amount of overall C not being taken up from the atmosphere by the forest, thus not accumulated in the biosphere.
Effects of biological invasions on forest carbon sequestration
Authors: PELTZER D. A. , ALLEN R. B. , LOVETT G. M. , WHITEHEAD D. , WARDLE D. A.
Published: July 2009

There has been a rapidly developing literature on the effects of some of the major drivers of global change on carbon (C) sequestration, particularly carbon dioxide (CO2) enrichment, land use change, nitrogen (N) deposition and climate change. However, remarkably little attention has been given to one major global change driver, namely biological invasions. This is despite growing evidence that invasive species can dramatically alter a range of aboveground and belowground ecosystem processes, including those that affect C sequestration. In this review, we assess the evidence for the impacts of biological invaders on forest C stocks and C sequestration by biological invaders. We first present case studies that highlight a range of invader impacts on C sequestration in forest ecosystems, and draw on examples that involve invasive primary producers, decomposers, herbivores, plant pathogens, mutualists and predators. We then develop a conceptual framework for assessing the effects of invasive species on C sequestration impacts more generally, by identifying the features of biological invaders and invaded ecosystems that are thought to most strongly regulate C in forests. Finally we assess the implications of managing invasive species on C sequestration. An important principle that emerges from this review is that the direct effects of invaders on forest C are often smaller and shorter‐term than their indirect effects caused by altered nutrient availability, primary productivity or species composition, all of which regulate long‐term C pools and fluxes. This review provides a conceptual basis for improving our general understanding of biological invaders on ecosystem C, but also points to a paucity of primary data that are needed to determine the quantitative effects of invaders on ecosystem processes that drive C sequestration.
Relating juvenile migration timing and survival to adulthood in two species of threatened Pacific salmon (Oncorhynchus spp.)
Authors: Scheuerell Mark D. , Zabel Richard W. , Sandford Benjamin P.
Published: July 2009

1.
 Migration timing in animals has important effects on life‐history transitions. Human activities can alter migration timing of animals, and understanding the effects of such disruptions remains an important goal for applied ecology. Anadromous Pacific salmon (Oncorhynchus spp.) inhabit fresh water as juveniles before migrating to the ocean where they gain >90% of their biomass before returning to fresh water as adults to reproduce. Although construction of dams has delayed juvenile migration for many populations, we currently lack a synthesis of patterns in migration timing and how they relate to subsequent survival to adulthood for Pacific salmon, especially for at‐risk populations.

2.
 We studied two groups of Pacific salmon from the Columbia River basin in the northwestern United States currently listed under the U.S. Endangered Species Act. We examined how the proportion of juveniles surviving to return as adults varied with year of migration, date of arrival in the estuary, water temperature and coastal ocean upwelling using data from over 40 000 individually tagged Chinook salmon Oncorhynchus tshawytscha and steelhead Oncorhynchus mykiss.

3.
 In general, models with year, day and day2 had much better support from the data than those with temperature and upwelling. For Chinook salmon, we also found a residual effect of temperature after controlling for day, but the effect was small for steelhead.

4.  For both species, juveniles migrating from early to mid‐May survived 4–50 times greater than those migrating in mid‐June. As expected, however, the estimated peak in survival varied among years, presumably reflecting interannual variation in the nearshore physical environment and trophic dynamics that affect salmon during the critical juvenile life stage.

5.
 Synthesis and applications. Our results indicate a possible management objective would be to speed arrival to the estuary by increasing springtime river flows. These findings also provide some insight into the mechanisms underlying seasonal differences in survival patterns, but additional studies are needed to better resolve the issue. Future changes to river flow and water temperature associated with climate change and human activities may further alter migration timing, and thus this phenomenon deserves further attention.
A critical assessment of two species distribution models: a case study of the vervet monkey (Cercopithecus aethiops)
Authors: Willems Erik P. , Hill Russell A.
Published: July 2009

Aim  Species distribution models are invaluable tools in biogeographical, ecological and applied biological research, but specific concerns have been raised in relation to different modelling techniques in terms of their validity. Here we compare two fundamentally different approaches to species distribution modelling, one based on simple occurrence data where the lack of an ecological framework has been criticized, and the other firmly based in socio‐ecological theory but requiring highly detailed behavioural information that is often limited in availability.

Location  (Sub‐Saharan) Africa.

Methods  We used two distinct techniques to predict the realized distribution of a model species, the vervet monkey (Cercopithecus aethiops Linnaeus, 1758). A maximum entropy model was produced taking 13 environmental variables and presence‐only data from 174 sites throughout Africa as input, with an additional 58 sites retained to test the model. A time‐budget model considering the same environmental variables was constructed from detailed behavioural data on 20 groups representing 14 populations, with presence‐only data from the remaining 218 sites reserved to test model predictions on vervet monkey occurrence. Both models were further validated against a reference species distribution map as drawn up by the African Mammals Databank.

Results  Both models performed well, with the time budget and maximum entropy algorithms correctly predicting vervet monkey presence at 78.4% and 91.4% of their respective test sites. Similarly, the time‐budget model correctly predicted presence and absence at 87.4% of map pixels against the reference distribution map, and the maximum entropy model achieved a success rate of 81.8%. Finally, there was a high level of agreement (81.6%) between the presence–absence maps produced by the two models, and the environmental variables identified as most strongly driving vervet monkey distribution were the same in both models.

Main conclusions  The time‐budget and maximum entropy models produced accurate and remarkably similar species distribution maps, despite fundamental differences in their conceptual and methodological approaches. Such strong convergence not only provides support for the credibility of current results, but also relieves concerns about the validity of the two modelling approaches.
Rapid evolution of great kiskadees on Bermuda: an assessment of the ability of the island rule to predict the direction of contemporary evolution in exotic vertebrates
Authors: Mathys Blake A. , Lockwood Julie L.
Published: July 2009

Aim  To determine whether an exotic bird species, the great kiskadee (Pitangus sulphuratus), has diverged in morphology from its native source population, and, if so, has done so in a manner predicted by the island rule. The island rule predicts that insular vertebrates will tend towards dwarfism or gigantism when isolated on islands, depending on their body size. For birds, the island rule predicts that species with body sizes below 70–120 g should increase in size. The great kiskadee has a mean mass of c. 60 g in its native range, therefore we predicted that it would increase in size within the exotic, and more insular, Bermudan range.

Location  The islands of Bermuda (exotic population) and Trinidad (native source population).

Methods  We took eight morphological measurements on 84 individuals captured in the exotic (Bermudan) population and 62 individuals captured in the native source (Trinidadian) population. We compared morphological metrics between populations using univariate and principal components analyses. We assessed whether the effects of genetic drift could explain observed differences in morphology. We calculated divergence rates in haldanes and darwins for comparison with published examples of contemporary evolution. Finally, we used mark–recapture analysis to determine the effects of the measured morphological characters on survivorship within the exotic Bermudan population.

Results  Individuals in the exotic Bermudan population have larger morphological dimensions than individuals in the native source population on Trinidad. The degree of divergence in body mass (g) and bill width (mm) is probably not due to genetic drift. This rate of divergence is nearly equal to that observed amongst well‐documented examples of contemporary bird evolution, and is within the mid‐range of rates reported across taxa. There is no clear effect of body size on survivorship as only one character (bill width) was found to have an influence on individual survivorship.

Main conclusions  Exotic species provide useful systems for examining evolutionary predictions over contemporary time‐scales. We found that divergence between the exotic and native populations of this bird species occurred over c. 17 generations, and was in the direction predicted by the island rule, a principle based on the study of native species.
An ethnographic study of forensic nursing culture in an Australian prison hospital
Authors: CASHIN A. , NEWMAN C. , EASON M. , THORPE A. , O'DISCOLL C.
Published: July 2009

Accessible summary

Forensic nurses are faced with unique challenges in their attempt to deliver nursing care in a custodial environment.

The impact of such challenges on the cultural dynamic of forensic nursing and consequently on healthcare delivery is largely unknown.

The aim of this ethnographic study was to explore the nursing culture within an Australian prison hospital and the migration of the culture over a 12‐month period.

At the end of the study, the nursing culture was found to be one of hope, although with no clearly articulated vision of nurse‐hood or patient‐hood and model within which to practice nursing.

The ability to articulate practice is central to the development of mental health nursing in any context.

Forensic nurses are faced with unique challenges in their attempt to deliver nursing care in a custodial environment. The impact of such challenges on the cultural dynamic of forensic nursing and consequently on healthcare delivery is largely unknown. The aim of this ethnographic study was to explore the nursing culture within an Australian prison hospital and the migration of the culture over a 12‐month period. At the end of the study the nursing culture was found to be one of hope, although with no clearly articulated vision of nurse‐hood or patient‐hood and model within which to practice nursing.
Complexity and context of MHC‐correlated mating preferences in wild populations
Authors: ROBERTS S. CRAIG
Published: July 2009

There is now substantial and growing evidence for a role of the major histocompatibility complex (MHC) in shaping individual mate preferences. In view of both its codominant expression and its function in immune response, it is often expected that females aim to avoid inbreeding or maximize offspring MHC‐heterozygosity by selecting as mates those males which share fewest or no MHC alleles with themselves. However, it is becoming increasingly clear that this view is over‐simplistic: not only is MHC dissimilarity just one of several (perhaps many) criteria important in mate choice decision‐making, extremely MHC‐dissimilar males may be avoided, and furthermore, specific alleles or combinations might be preferred if they bestow particular advantages. These points are raised in two papers in this Molecular Ecology issue, in which patterns of reproductive success in tiger salamanders (Ambystoma tigrinum) and three‐spined sticklebacks (Gasterosteus aculeatus) are each inconsistent with a generalized preference for MHC dissimilarity. Together, these studies demonstrate several adaptive reasons for decision rules that do not necessarily result in maximizing mate dissimilarity.
Immunity and symbiosis
Authors: Gross Roy , Vavre Fabrice , Heddi Abdelaziz , Hurst Gregory D. D. , Zchori‐Fein Einat , Bourtzis Kostas
Published: July 2009

The invertebrate immune system, which has become a major research focus, shares basic features of innate immunity with vertebrates and men. A special feature apparently found only in invertebrates is their close association with vertically heritable symbiotic microorganisms. The validity of the simple view of symbiosis as a mutually beneficial interaction between two uneven partners mainly improving the nutritional state of the two companions has been challenged, however, as symbiotic interactions might involve more partners, and symbiotic functions of the microorganisms are much more diverse than previously assumed. Likewise, microorganisms considered to be mostly harmful to their hosts have been shown to enhance host fitness under some circumstances. The role of a symbiont itself might change between environments or life stages of the host and symbionts might have features previously thought to be specific for pathogens. Understanding symbiotic interactions requires the comprehension of the cross‐talk between the symbiotic companions, and the dissection of how long‐lasting infections are established without eliminating the symbiont by host immune responses. Fascinating new findings in this field revealed that symbiosis might contribute to defence against pathogens or natural enemies. New symbiont‐based approaches to defeat agricultural pests or pathogen transmission by arthropod vectors are becoming conceivable.
In vitro comparison of the complement‐scavenging capacity of different intravenous immunoglobulin preparations
Authors: Spycher M. , Matozan K. , Minnig K. , Zehnder R. , Miescher S. , Hoefferer L. , Rieben R.
Published: July 2009

Background and Objectives  Complement inhibition is considered important in the mechanism of action of intravenous immunoglobulin (IVIG) in a number of inflammatory and autoimmune disorders. The capacity of different IVIG preparations to ‘scavenge’ activated C3 and thereby inhibit complement activation was assessed by a new in vitro assay.

Materials and Methods  Diluted human serum as a complement source, with or without addition of different concentrations of IVIG, was incubated in microtitre plates coated with heat‐aggregated human IgG. Complement scavenging was measured by detecting reduced C3 binding and determining fluid phase C3b–IgG complex formation. Complement activation induced by the IVIG preparations was measured as C5a formation.

Results  All IVIG preparations exhibited a dose‐dependent inhibition of C3b deposition, correlating strongly with binding of C3b to fluid‐phase IgG, but the extent of complement scavenging varied considerably between different IVIG preparations. At an IVIG concentration of 0·9 mg/ml, the inhibition of C3b deposition ranged from 72 ± 16% to 22 ± 4·1%. The reduction of C3b deposition on the complement‐activating surface was not due to IVIG‐induced complement activation in the fluid phase, as shown by the low C5a formation in the presence of serum.

Conclusion  In vitro analysis allows comparison of the complement‐inhibitory properties of IVIG preparations. The extent of complement scavenging varies between the products.
Structure of the Oesophagus and Morphometric, Histochemical–Immunohistochemical Profiles of the Oesophageal Gland During the Post‐hatching Period of Japanese Quails (Coturnix coturnix japonica)
Authors: Sağsöz H. , Lıman N.
Published: July 2009

In the oesophagus, mucins, which originate from oesophageal submucosal glands, play an important role in the mucosal protection as a pre‐epithelial barrier. In this study, the structure of cervical and thoracic parts of oesophagus of Japanese quail during the post‐hatching period was compared, and the contents of carbohydrate and gastric mucin MUC5AC of the oesophageal glands in these parts were analysed at the light microscope levels by applying conventional histochemical and immunohistochemical methods. The oesophageal glands were present at hatching, located in the laminae propria. The numbers of glands were different in the cervical and thoracic parts, but the differences were found to be insignificant. The thoracic part has the oesophageal tonsils which are associated with the glands. Oesophageal tonsil was formed from day 5 after hatching. In quail of all ages, the secretory epithelium of glands contained neutral sialomucins and weakly sulphomucins. The cells in the neck region of secretory units contained sialomucins, while the cells of excretory ducts had strongly sulphomucins. Sialomucin containing cells in the secretory units increased with the advance of age and glandular development. But, in the secretory units, the sulphomucin content of glands was more in the thoracic part. The secretory epithelium of tonsil‐associated glands contained mostly sulphomucins and a little sialomucin. From the hatching, MUC5AC mucin was detected in the cells of excretory ducts. Although the lymphoepithelium of the tonsil units exhibited negative reactions to all histochemical methods, it showed positive reaction to MUC5AC mucin antibody. In conclusion, the cervical and thoracic parts may be functionally different and the thoracic part of oesophagus was transformed into an immunological organ following day 5 after hatching.
Bioactivity of fenchone and Plectranthus glandulosus oil against Prostephanus truncatus and two strains of Sitophilus zeamais
Authors: Nukenine E. N. , Adler C. , Reichmuth Ch.
Published: July 2009

The toxic, repellent and reproduction inhibitory effects of Plectranthus glandulosus essential oil and one of its major compounds, fenchone, were evaluated against adult Prostephanus truncatus (Horn) and for two strains of Sitophilus zeamais Motschulsky from Cameroon and Germany. Maize grains were coated with the oil at 0, 10, 20, 40 and 80 μl/40 g grain and fenchone at 0, 20, 40, 80 and 120 μl/40 g grain. Mortality was assessed over a 7‐day period, followed by the determination of F1 progeny production. The repellence of the two products was evaluated at five rates (0.5, 1, 3, 5, 10 μl/half disc) in a choice bioassay on filter paper. The oil and fenchone caused significant dose‐dependent mortality to the three insects, with the oil achieving 100% and 90% mortality for the two S. zeamais strains and P. truncatus, respectively, within 1 day of exposure at the dosage of 80 μl/40 g grain. The insects were less susceptible to fenchone compared with the crude oil. The German strain of S. zeamais was susceptible to the oil than the Cameroonian strain. At the dosage of 20 μl/40 g grain, S. zeamais F1 progeny emergency was completely inhibited by the oil, while 80 μl/40 g grain treatment with fenchone prevented also insect emergence. Plectranthus glandulosus oil generally evoked a maximum per cent repellency of 100% for the three insects, but fenchone caused 55–60% to S. zeamais and 80% to P. truncatus. These results suggest that fenchone, though a major constituent of P. glandulosus oil, may only be a minor component of its bioactivity.
Study of the macrophyte assemblages and application of phytobenthic indices to assess the Ecological Status of the Marano‐Grado Lagoon (Italy)
Authors: Falace Annalisa , Curiel Daniele , Sfriso Adriano
Published: July 2009

Benthic macrophytes from 19 sites within the Marano‐Grado Lagoon were sampled in July 2007 in order to update the available information on the flora and vegetation and to assess the Ecological Status (ES) within the European Water Framework Directive (WFD). Data on macrophytes were analysed using two phytobenthic indices (EEI and R‐MaQI) recently set up to evaluate the ecological status of transitional environments in the Mediterranean eco‐region. Notwithstanding the extension (c. 160 km2) that places this lagoon as the second largest Italian transitional environment, ecological studies are relatively few. The present research revealed a relatively poor flora, mainly characterized by the dominance of low‐diversity settlements of Ulvaceae. Moreover, the absence of intensive aquaculture activities and commercial big harbours, which account for the new species introductions recorded in other lagoons, limits the presence of non‐autochthonous species. The comparison with previous data (Curiel et al. 1998) highlighted the reduction of macrophyte coverage and biomass, especially Ulvaceae stands, and an increase in species richness. In particular, there was evidence of a worsening of the area north of the Grado bridge. This area, which in the past was colonized by widespread angiosperm coverage, at present is almost lacking in vegetation. According to these observations, by applying both the phytobenthic indices available in the literature for the transitional environments, the Marano‐Grado Lagoon showed a ‘Good–High’ quality in the central part of the basin and near the lagoon inlets and a ‘Poor–Bad’ quality in the northern and southern areas. The evaluation of some physico‐chemical parameters, coupled with the distribution of the angiosperms, also allowed a first delineation of the main lagoon water bodies.
Consent issues and pediatric regional anesthesia
Authors: LÖNNQVIST PER‐ARNE , MORTON NEIL S. , ROSS ALLISON K.
Published: July 2009

The need for consent to regional anesthetic procedures varies considerably between countries. It is likely that legislation and professional guidance will tighten consent procedures, and in several countries detailed written consent is required for regional blockade. This article discusses aspects of consent to regional anesthesia in children.