bluuebunny/crossref_metadata_2025 huggingface dataset:
The peroxisomal import proteins PEX2, PEX5 and PEX7 are differently involved in Podospora anserina sexual cycle
Authors: Bonnet Crystel , Espagne Eric , Zickler Denise , Boisnard Stéphanie , Bourdais Anne , Berteaux‐Lecellier Véronique
Published: August 2006

PEX5, PEX7 and PEX2 are involved in the peroxisomal matrix protein import machinery. PEX5 and PEX7 are the receptors for the proteins harbouring, respectively, a PTS1 and a PTS2 peroxisomal targeting sequence and cycle between the cytoplasm and the peroxisome. PEX2 belongs to the RING‐finger complex located in the peroxisomal membrane and acts in protein import downstream of PEX5 and PEX7; it is therefore required for the import of both PTS1 and PTS2 proteins. We have shown previously that PEX2 deficiency leads to an impairment of meiotic commitment in the filamentous fungus Podospora anserina. Here we report that both PEX5 and PEX7 receptors are dispensable for this commitment but are needed for normal sexual cycle. Data suggest also a new role of PEX2 and/or the RING‐finger complex in addition to their role in PTS1 and PTS2 import. Strikingly, Δpex5 and Δpex7 single and double knockout strains analyses indicate that Δpex7 acts as a partial suppressor of Δpex5 life cycle deficiencies. Moreover, contrary to pex2 mutants, Δpex5 and Δpex7 show mitochondrial morphological abnormalities.
A novel signal transduction system and feedback loop regulate fructan hydrolase gene expression in Streptococcus mutans
Authors: Zeng Lin , Wen Zezhang T. , Burne Robert A.
Published: August 2006

The fruA gene of Streptococcus mutans encodes for a secreted fructan hydrolase (fructanase), an established virulence determinant required for releasing d‐fructose from levan‐ and inulin‐type fructans. Expression of fruA is under the control of carbon catabolite repression and is induced by growth in fructans. In this report, we identified an operon in S. mutans UA159 encoding a two‐component system flanked by two predicted carbohydrate‐binding proteins that is absolutely required for the expression of fruA. All four genes were found to be required for optimal growth of S. mutans on inulin‐containing medium and for transcriptional activation of fruA. Complementation assays using a plasmid expressing the response regulator suggested that the two‐component system works in concert with the sugar‐binding proteins. This operon was also shown to activate a four‐gene cluster located immediately downstream and encoding an Enzyme II (EIILev) for a fructose/mannose sugar : phosphotransferase enzyme, which was found to negatively regulate the expression of fruA. Using transcriptional fusions, it was found that fructose could signal induction of the fruA and levD operons through the two‐component system/sugar‐binding protein complex. A recombinant LevR protein was shown to bind to the promoter regions of fruA and levD in gel mobility shift assays. Thus, a ‘four‐component signal transduction system’ activates fructan catabolism and the expression of an Enzyme II complex that functions in a feedback loop to sense the accumulation of the end‐product of fructan degradation.
The F‐box protein Grr1 regulates the stability of Ccn1, Cln3 and Hof1 and cell morphogenesis in Candida albicans
Authors: Li Wan Jie , Wang Yan Ming , Zheng Xin De , Shi Qing Mei , Zhang Ting Ting , Bai Chen , Li Di , Sang Jian Li , Wang Yue
Published: August 2006

Both G1 and mitotic cyclins have been implicated in regulating Candida albicans filamentous growth. We have investigated the functions of Grr1 whose orthologue in Saccharomyces cerevisiae is known to mediate ubiquitin‐dependent degradation of the G1 cyclins Cln1 and Cln2. Here, we report that deleting C. albicans GRR1 causes significant stabilization of two G1 cyclins Ccn1 and Cln3 and pseudohyphal growth. grr1Δ cells are highly heterogeneous in length and many of them fail to separate after cytokinesis. Interestingly, some isolated rod‐like G1 cells of similar sizes are present in the grr1Δ culture. Time‐lapse microscopy revealed that the rod‐shaped G1 cells first grew exclusively in width before budding and then the bud grew exclusively by apical extension until after cytokinesis, yielding rod‐like daughter cells. Consistently, actin patches persistently localize to the bud tip until around the time of cytokinesis. Despite the pseudohyphal phenotype, grr1Δ cells respond normally to hyphal induction. Hyperphosphorylated Cln3 isoforms accumulate in grr1Δ cells, indicating that Grr1 selectively mediates their degradation in wild‐type cells. grr1Δ pseudohyphal growth requires neither Hgc1 nor Swel, two important regulators of cell morphogenesis. Furthermore, the cellular level of Hof1, a protein having a role in cytokinesis, is also significantly increased in grr1Δ cells.
Implementing a comprehensive cost information system in rural health facilities: the case of Nouna health district, Burkina Faso
Authors: Flessa Steffen , Kouyaté Bocar
Published: August 2006

Objectives  To present first findings of a cost‐of‐illness (COI) information system implemented in Nouna health district, Burkina Faso. The entire project will include household and provider tangible COI, whereas this article concentrates on the development of a provider cost information system in rural first‐line health facilities.

Method  Special forms and reports are prepared to routinely collect capital and recurrent costs of first‐line facilities. Inventory lists are designed, and buildings and equipment are assessed by engineers. Total, fixed, variable and average costs are calculated for 15 rural health centres with five cost centres: general outpatient consultation, ambulatory nursing care, deliveries, immunization and other services (neonatal consultation, child care and family planning).

Results  In 2003, the average costs per service unit were 1.34 US$ for a general consultation, 0.51 US$ for ambulatory nursing care, 6.73 US$ per delivery, 3.64 US$ per vaccination and 1.11 US$ per service unit of other care. On average, a health centre consumes 29 900 US$ per year for a catchment population of 10 000 inhabitants.

Conclusions  The major share of costs is fixed and does not depend on the workload of the health centre. Consequently, the costs of first‐line facilities will hardly increase if the demand for health services rises. These findings can be used to improve the health financing in Nouna health district, Burkina Faso.
Detection of adult Brugia malayi filariae by ultrasonography in humans in India and Indonesia
Authors: Mand S. , Supali T. , Djuardi J. , Kar S. , Ravindran B. , Hoerauf A.
Published: August 2006

In bancroftian filariasis, ultrasonography (USG) is a suitable tool to monitor infection by the detection of adult filariae in addition to antigen detection tests (ICT, Og4C3). However, in brugian filariasis, ultrasound examinations in humans have so far failed to detect adult worms and no antigen test is available to verify infections in patients who are carriers of adult worms but amicrofilaraemic. In this study, we describe the feasibility of detection of adult Brugia malayi filariae by USG. Worm nests were detected in 4 of 32 patients in India and Indonesia, located in the breast, the thigh, the calf and an inguinal lymph node. The study shows that adult filariae of B. malayi in humans can be detected by USG, but the technique is limited by the fact that worm nests seem not to be stable over time in humans, as is the case in bancroftian filariasis.
Genotype‐by‐environment interactions leads to variable selection on life‐history strategy in Common Evening Primrose (Oenothera biennis)
Authors: JOHNSON M. T. J.
Published: August 2006

Monocarpic plant species, where reproduction is fatal, frequently exhibit variation in the length of their prereproductive period prior to flowering. If this life‐history variation in flowering strategy has a genetic basis, genotype‐by‐environment interactions (G × E) may maintain phenotypic diversity in flowering strategy. The native monocarpic plant Common Evening Primrose (Oenothera biennis L., Onagraceae) exhibits phenotypic variation for annual vs. biennial flowering strategies. I tested whether there was a genetic basis to variation in flowering strategy in O. biennis, and whether environmental variation causes G × E that imposes variable selection on flowering strategy. In a field experiment, I randomized more than 900 plants from 14 clonal families (genotypes) into five distinct habitats that represented a natural productivity gradient. G × E strongly affected the lifetime fruit production of O. biennis, with the rank‐order in relative fitness of genotypes changing substantially between habitats. I detected genetic variation in annual vs. biennial strategies in most habitats, as well as a G × E effect on flowering strategy. This variation in flowering strategy was correlated with genetic variation in relative fitness, and phenotypic and genotypic selection analyses revealed that environmental variation resulted in variable directional selection on annual vs. biennial strategies. Specifically, a biennial strategy was favoured in moderately productive environments, whereas an annual strategy was favoured in low‐productivity environments. These results highlight the importance of variable selection for the maintenance of genetic variation in the life‐history strategy of a monocarpic plant.
Male mating preferences pre‐date the origin of a female trait polymorphism in an incipient species complex of Lake Victoria cichlids
Authors: PIEROTTI M. E. R. , SEEHAUSEN O.
Published: August 2006

Disruptive sexual selection on colour patterns has been suggested as a major cause of diversification in the cichlid species flock of Lake Victoria. InNeochromis omnicaeruleus, a colour and sex determination polymorphism is associated with a polymorphism in male and female mating preferences. Theoretical work on this incipient species complex found conditions for rapid sympatric speciation by selection on sex determination and sexual selection on male and female colour patterns, under restrictive assumptions. Here we test the biological plausibility of a key assumption of such models, namely, the existence of a male preference against a novel female colour morph before its appearance in the population. We show that most males in a population that lacks the colour polymorphism exhibit a strong mating preference against the novel female colour morph and that reinforcement is not a likely explanation for the origin of such male preferences. Our results show that a specific condition required for the combined action of selection on sex determination and sexual selection to drive sympatric speciation is biologically justified. Finally, we suggest that Lake Victoria cichlids might share an ancestral female recognition scheme, predisposing colour monomorphic populations/species to similar evolutionary pathways leading to divergence of colour morphs in sympatry.
Comparison of Three Diagnostic Detection Methods for Tuberculosis in French Cattle
Authors: Watrelot‐Virieux D. , Drevon‐Gaillot E. , Toussaint Y. , Belli P.
Published: August 2006

Three additional techniques (Ziehl–Neelsen, auramine O/rhodamine and immunostaining using polyclonal anti‐Mycobacterium bovis) to hematoxylin‐eosin histopathology were evaluated for bovine tuberculosis diagnosis on 39 samples from several slaughterhouses. The immunohistochemichal technique was more sensitive and could detect a greater number of positive cattle. It has about the same sensibility as the bacteriology but it was faster.
Comparative Assessment of the Antimicrobial Susceptibility ofStaphylococcus aureusIsolates from Bovine Mastitis in Biofilm Versus Planktonic Culture
Authors: Melchior M. B. , Fink‐Gremmels J. , Gaastra W.
Published: August 2006

Mastitis is one of the most important diseases in dairy cattle of whichStaphylococcus aureusis a major pathogen. Despite an apparently good antimicrobial susceptibilityin vitro, the cure of diseased animals from this bacteriological infection is often disappointing, which results in cases of recurrent clinical‐ and chronic subclinical infections. It has been suggested that these recurrent and chronicStaphylococcusinfections can be attributed to the growth of bacteria in biofilm. The objective of this study was to compare the susceptibility for antimicrobial agents ofS. aureusisolates obtained from bovine mastitis growing under different conditions. These conditions include a conventional conventional microbroth dilution assay in which minimal inhibitory concentration values are determined, the MBECTMassay which measures both the susceptibility in biofilm and the susceptibility of sequester cells released from the biofilm. A comparison of the susceptibility for antimicrobial agents of a number of representativeS. aureusisolates grown in broth (representingin vitrogrowth conditions) or milk (representingin vivogrowth conditions) is also made. The results indicate thatS. aureusisolates obtained from bovine mastitis are highly resistant to antimicrobial agents when growing in biofilms.
Emerging Enterohaemorrhagic Escherichia coli, Causes and Effects of the Rise of a Human Pathogen
Authors: Beutin L.
Published: August 2006

Shiga toxin (Stx) [Verotoxin (VT)]‐producing Escherichia coli (STEC), also called enterohaemorrhagic E. coli or VTEC are emerging zoonotic agents and became most important as human pathogens, particularly in the industrialized countries. Production of cytotoxins, also called Stx or VT, is the major pathogenicity determinant of STEC, which can cause life‐threatening haemorrhagic diseases in humans. The spectrum of STEC phenotypes is diverse and domestic and wildlife animals constitute important reservoirs for these bacteria. STEC are spread from animal faeces to the environment, water and food. Ingestion of contaminated foodstuff and water, as well as contact with the environment, STEC‐excreting animals or humans are the major sources of human infection. Economical changes in animal and food production, alteration of consumer habits and lack of specific immune response, particularly in urbanized populations, have contributed to the recent spread of STEC as a zoonotic agent. Supranational surveillance networks as well as national reference laboratories as sentinels play an important role in the prevention and control of STEC infections in humans. Development of new vaccines and probiotics may serve as future tools to control the spread of STEC in animals and humans.
Primary intraosseous melanotic schwannoma of the fibula associated with the Carney complex
Authors: Kim Mi‐Jung , Choi Jene , Khang Shin‐Kwang , Kim Jung‐Sun , Lee Jong‐Seok , Cho Kyung‐Ja
Published: August 2006

Described herein is a rare case of intraosseous melanotic schwannoma (MS) occurring in a long bone of a 13‐year‐old girl with a loss of heterozygosity (LOH) at 17q22‐24, which contains the PRKAR1A gene encoding the protein kinase A regulatory subunit 1‐a. Plain radiography and magnetic resonance imaging revealed a 10 cm expansile osteolytic lesion involving the proximal fibula. An excisional biopsy revealed a cellular tumor consisting of mildly pleomorphic spindle or oval to polygonal cells with frequent intranuclear pseudoinclusions, intracytoplasmic melanin pigments, nuclear palisades, Verocay body‐like structures, and psammomatous calcifications. The tumor cells showed strong immunoreactivity for S‐100 protein, HMB‐45, and neuron‐specific enolase. Ultrastructurally, the tumor cells were invested by continuous, multiplied external lamina and conspicuous melanosomes in various stages of maturation. These observations were compatible with psammomatous melanotic schwannoma (PMS). In addition, the detection of LOH for PRKAR1A strongly suggests that PMS in the present case is a manifestation of the Carney complex (CNC).
Pancreatic cancer initially presenting with a pseudocyst at the splenic flexure
Authors: Inagi Eiji , Shimodan Shun , Amizuka Hisato , Kigawa Sanshiro , Shimizu Yozo , Nagashima Kazuo , Tanaka Shinya
Published: August 2006

Pancreatic cancer and pancreatitis associated pseudocyst are not uncommon disorders. However, occurrence of the cancer with an initial manifestation of pseudocyst has been rarely reported. Surgery was performed on a 44‐year‐old male patient for an abscess‐like cavity situated at the mesenteric side of the colon and extending from the splenic flexure to the descending colon. The lesion was verified as a pseudocyst with fat necrosis due to leakage of pancreatic fluid. When further surgery was carried out 1 month later in order to manage the drainage site of the pancreatic fluid, cancer of the pancreas body was detected proximal to the drainage site. The cancer was a moderately differentiated ductal adenocarcinoma with wide peripancreatic infiltration. It is thought that the cancer‐associated duct obstruction caused a local pancreatitis resulting in a large communicating pseudocyst, although the exact mechanism remains unresolved. The present case may be instructive in showing physicians that a pseudocyst may obscure the presence of pancreatic cancer.
Protective effects of EUK4010 on β‐amyloid(1–42) induced degeneration of neuronal cells
Authors: Sun Liwen , Wang Li , Sun Yong , Tang Syao‐wei , Hu Yinghe
Published: August 2006

EUK4010 has been identified to exhibit an inhibitory effect on β‐amyloid (Aβ)1−42‐induced loss of neuronal cell viability. Further studies demonstrated that EUK4010 attenuated the Aβ1−42‐induced degeneration in both cultured rat hippocampal neurons and human neuroblastoma cells, as demonstrated by typical morphological changes, cell viability and the chip‐based flow cytometric assay. Gene expression analysis using DNA microarray showed that the senescence marker calcium‐binding protein, regucalcin (Rgn), GABA‐A receptor pi subunit (Gabrp), the huntingtin binding protein, optineurin (Optn) and a semaphorin family plexin A3 similar protein (Plex‐similar) changed their expression levels significantly in cultured neurons after Aβ1−42 treatment. In this report, we have undertaken a chemical genetic approach to study the molecular basis of Aβ1−42 effects on the neuronal degeneration. Our results demonstrate that EUK4010 completely blocked the Aβ1−42‐induced up‐regulation of GABA‐A receptor pi subunit and the semaphorin family plexin A3 similar protein, and partially attenuated the down‐regulation of senescence marker calcium‐binding protein, regucalcin. These observations suggest that EUK4010 may prevent or reduce the Aβ toxicity by regulating the expression of genes involved in the Aβ induced neuronal degeneration. These genes may represent a promising target for the therapeutic drug development for Alzheimer's disease (AD) and other neurological disorders. Furthermore, EUK4010 and its analogues could potentially be developed as neuronal protective agents for the treatment of these diseases.
The Kölliker‐Fuse nucleus gates the postinspiratory phase of the respiratory cycle to control inspiratory off‐switch and upper airway resistance in rat
Authors: Dutschmann Mathias , Herbert Horst
Published: August 2006

Lesion or pharmacological manipulation of the dorsolateral pons can transform the breathing pattern to apneusis (pathological prolonged inspiration). Apneusis reflects a disturbed inspiratory off‐switch mechanism (IOS) leading to a delayed phase transition from inspiration to expiration. Under intact conditions the IOS is irreversibly mediated via activation of postinspiratory (PI) neurons within the respiratory network. In parallel, populations of laryngeal premotoneurons manifest the IOS by a brief glottal constriction during the PI phase. We investigated effects of pontine excitation (glutamate injection) or temporary lesion after injection of a GABA‐receptor agonist (isoguvacine) on the strength of PI‐pool activity determined from respiratory motor outputs or kinesiological measurements of laryngeal resistance in a perfused brainstem preparation. Glutamate microinjections into distinct parts of the pontine Kölliker‐Fuse nucleus (KF) evoked a tonic excitation of PI‐motor activity or sustained laryngeal constriction accompanied by prolongation of the expiratory phase. Subsequent isoguvacine microinjections at the same loci abolished PI‐motor or laryngeal constrictor activity, triggered apneusis and established a variable and decreased breathing frequency. In summary, we revealed that excitation or inhibition of defined areas within the KF activated and blocked PI activity and, consequently, IOS. Therefore, we conclude, first, that descending KF inputs are essential to gate PI activity required for a proper pattern formation and phase control within the respiratory network, at least during absence of pulmonary stretch receptor activity and, secondly, that the KF contains large numbers of laryngeal PI premotor neurons that might have a key role in the regulation of upper airway resistance during reflex control and vocalization.
Action‐potential initiation and maintained activity of the isolated frog muscle spindle
Authors: Querfurth H.
Published: August 2006

The initiation of afferent action potentials represents the basic signalling process integrating and coding information of an external stimulus. There is also evidence in sensory receptor neurons of spontaneously generating action potentials that interfere with and modify the stimulus evoked activity. The present study investigates the generation of spontaneous action potentials in the isolated muscle spindle of the frog by recording receptor potentials, small subthreshold depolarizations, propagated impulses and interspike transients from the first Ranvier‐node of the afferent stem fibre. The temporal pattern of spontaneous discharges at resting length depended on several variables interacting at the encoding site. In the absence of mechanical stimulation, a large resting receptor potential steadily depolarized the encoding node and provoked action potentials at irregular intervals. After each action potential, the hyperpolarizing afterpotential provided a slowly increasing depolarizing interspike transient of decreasing slope (time constant 128 ms), which evoked small subthreshold depolarizations (decay time > 5 ms; multimodal amplitude distribution) before the following action potential discharged. The probability of the small subthreshold depolarizations increased the longer the resting receptor potential stayed constant at its maximum amplitude. When increasing the static prestretch level encoding depended also on the stretch‐evoked receptor potential as an additional parameter. The resulting depolarizing interspike transients were then larger and also more steeply rising, so that the afferent discharges increased in both rate and regularity. The experiments show dynamic threshold patterns that control action‐potential initiation by the assessment of the actual amplitude of depolarization and its rate of rise.
Induction of BIMEL following growth factor withdrawal is a key event in caspase‐dependent apoptosis of 661W photoreceptor cells
Authors: Gómez‐Vicente Violeta , Doonan Francesca , Donovan Maryanne , Cotter Thomas G.
Published: August 2006

Apoptosis of photoreceptor cells in the early postnatal period is a normal feature of mammalian retinal development. The role of mitochondria and caspases in the process has been well established; however, the identification of key apoptotic mediators still remains elusive. Here we report that BIMEL, a pro‐apoptotic BCL‐2 family member, may be one such molecule. Following growth factor deprivation, BIMEL was up‐regulated in mouse 661W cone photoreceptors. This event correlated with the release of mitochondrial apoptogenic factors into the cytosol, the activation of caspases and apoptosis. Moreover, a similar behaviour was observed in response to UV radiation, ionomycin or H2O2 treatments. We identified the PI3K–Akt–FKHRL1 signalling cascade as the main regulatory pathway of BIMEL expression in these cells. Finally, using RNA interference, we were able to silence BIMEL expression and subsequently suppress caspase‐3 activation. In conclusion, we propose BIMEL as a critical factor in mitochondria‐dependent apoptosis of 661W photoreceptors.
Synaptic inputs to retinal ganglion cells that set the circadian clock
Authors: Perez‐Leon Jorge Alberto , Warren Erin J. , Allen Charles N. , Robinson David W. , Lane Brown R
Published: August 2006

Melanopsin‐containing retinal ganglion cells (RGCs) project to the suprachiasmatic nuclei (SCN) and mediate photoentrainment of the circadian system. Melanopsin is a novel retinal‐based photopigment that renders these cells intrinsically photosensitive (ip). Although genetic ablation of melanopsin abolishes the intrinsic light response, it has a surprisingly minor effect on circadian photoentrainment. This and other non‐visual responses to light are lost only when the melanopsin deficiency is coupled with mutations that disable classical rod and cone photoreceptors, suggesting that melanopsin‐containing RGCs also receive rod‐ and cone‐driven synaptic inputs. Using whole‐cell patch‐clamp recording, we demonstrate that light triggers synaptic currents in ipRGCs via activation of ionotropic glutamate and γ‐aminobutyric acid (GABA) receptors. Miniature postsynaptic currents (mPSCs) were clearly observed in ipRGCs, although they were less robust and were seen less frequently than those seen in non‐ip cells. Pharmacological treatments revealed that the majority of ipRGCs receive excitatory glutamatergic inputs that were blocked by DNQX and/or kynurenic acid, as well as inhibitory GABAergic inputs that were blocked by bicuculline. Other ipRGCs received either glutamatergic or GABAergic inputs nearly exclusively. Although strychnine (Strych)‐sensitive mPSCs were evident on many non‐ipRGCs, indicating the presence of glycinergic inputs, we saw no evidence of Strych‐sensitive events in ipRGCs. Based on these results, it is clear that SCN‐projecting RGCs can respond to light both via an intrinsic melanopsin‐based signaling cascade and via a synaptic pathway driven by classical rod and/or cone photoreceptors. It remains to be determined how the ipRGCs integrate these temporally distinct inputs to generate the signals that mediate circadian photoentrainment and other non‐visual responses to light.
The role of peripheral Na+ channels in triggering the central excitatory effects of intravenous cocaine
Authors: Brown P. Leon , Kiyatkin Eugene A.
Published: August 2006

While alterations in dopamine (DA) uptake appear to be a critical mechanism underlying locomotor and reinforcing effects of cocaine (COC), many centrally mediated physiological and affective effects of this drug are resistant to DA receptor blockade and are expressed more quickly following an intravenous (i.v.) injection than expected based on the dynamics of drug concentration in the brain. Because COC is also a potent local anesthetic, its rapid action on Na+ channels may be responsible for triggering these effects. We monitored temperatures in the nucleus accumbens, temporal muscle and skin together with conventional locomotion during a single i.v. injection of COC (1 mg/kg), procaine (PRO, 5 mg/kg; equipotential anesthetic dose), a short‐acting local anesthetic drug that, like COC, interacts with Na+ channels, and cocaine methiodide (COC‐MET, 1.31 mg/kg, equimolar dose), a quaternary COC derivative that is unable to cross the blood–brain barrier. In this way, we explored not only the importance of Na+ channels in general, but also the importance of central vs. peripheral Na+ channels specifically. COC induced locomotor activation, temperature increase in the brain and muscle, and a biphasic temperature fluctuation in skin. Though PRO did not induce locomotor activation, it mimicked, to a greater degree, the temperature effects of COC. Therefore, Na+ channels appear to be a key substrate for COC‐induced temperature fluctuations in the brain and periphery. Similar to PRO, COC‐MET had minimal effects on locomotion, but mimicked COC in its ability to increase brain and muscle temperature, and induce transient skin hypothermia. It appears therefore that COC's interaction with peripherally located Na+ channels triggers its central excitatory effects manifested by brain temperature increase, thereby playing a major role in drug sensing and possibly contributing to COC reinforcement.
How parasites affect interactions between competitors and predators
Authors: Hatcher Melanie J. , Dick Jaimie T. A. , Dunn Alison M.
Published: August 2006

We present a synthesis of empirical and theoretical work investigating how parasites influence competitive and predatory interactions between other species. We examine the direct and indirect effects of parasitism and discuss examples of density and parasite‐induced trait‐mediated effects. Recent work reveals previously unrecognized complexity in parasite‐mediated interactions. In addition to parasite‐modified and apparent competition leading to species exclusion or enabling coexistence, parasites and predators interact in different ways to regulate or destablize the population dynamics of their joint prey. An emerging area is the impact of parasites on intraguild predation (IGP). Parasites can increase vulnerability of infected individuals to cannibalism or predation resulting in reversed species dominance in IGP hierarchies. We discuss the potential significance of parasites for community structure and biodiversity, in particular their role in promoting species exclusion or coexistence and the impact of emerging diseases. Ongoing invasions provide examples where parasites mediate native/invader interactions and play a key role in determining the outcome of invasions. We highlight the need for more quantitative data to assess the impact of parasites on communities, and the combination of theoretical and empirical studies to examine how the effects of parasitism scale up to community‐level processes.
Off‐axis symbiosis found: characterization and biogeography of bacterial symbionts of Bathymodiolus mussels from Lost City hydrothermal vents
Authors: DeChaine Eric G. , Bates Amanda E. , Shank Timothy M. , Cavanaugh Colleen M.
Published: August 2006

Organisms at hydrothermal vents inhabit discontinuous chemical ‘islands’ along mid‐ocean ridges, a scenario that may promote genetic divergence among populations. The 2003 discovery of mussels at the Lost City Hydrothermal Field provided a means of evaluating factors that govern the biogeography of symbiotic bacteria in the deep sea. The unusual chemical composition of vent fluids, the remote location, and paucity of characteristic vent macrofauna at the site, raised the question of whether microbial symbioses existed at the extraordinary Lost City. If so, how did symbiotic bacteria therein relate to those hosted by invertebrates at the closest known hydrothermal vents along the Mid‐Atlantic Ridge (MAR)? To answer these questions, we performed microscopic and molecular analyses on the bacteria found within the gill tissue of Bathymodiolus mussels (Mytilidae, Bathymodiolinae) that were discovered at the Lost City. Here we show that Lost City mussels harbour chemoautotrophic and methanotrophic endosymbionts simultaneously. Furthermore, populations of the chemoautotrophic symbionts from the Lost City and two sites along the MAR are genetically distinct from each other, which suggests spatial isolation of bacteria in the deep sea. These findings provide new insights into the processes that drive diversification of bacteria and evolution of symbioses at hydrothermal vents.
Surgery for local recurrence of rectal cancer
Authors: Heriot A. G. , Tekkis P. P. , Darzi A. , Mackay J.
Published: August 2006

Objective  Despite improvement in management of primary rectal cancer, 2.6–32% of patients develop local recurrence. A proportion of these patients can be amenable to salvage surgery. The present article reviews the evidence for and against the surgical management for local recurrence of rectal cancer, the role of adjuvant and intraoperative radiotherapy (IORT), and evaluates short and long‐term outcomes.

Method  A literature search was performed using Medline, Embase, Ovid and Cochrane database for studies between 1980 and 2005 assessing surgical management of local recurrence of rectal cancer and the evidence was critically evaluated.

Results  Nearly 50% of rectal cancer recurrences are local and are therefore potentially amenable to curative resection. Preoperative imaging is important for appropriate selection of patients for surgery and preoperative adjuvant therapy is essential. Five‐year survival following resection ranges from 18% to 58% with 5‐year survival following complete resection of over 35% though morbidity ranges from 21% to 82%. Neoadjuvant radiotherapy is beneficial and IORT may have a contributory role in treatment. Aggressive surgical treatment favourably affects quality of life and is cost effective.

Conclusion  Surgery for local recurrence can result in significant long‐term survival with acceptable morbidity and improved quality of life in appropriately selected patients. Assessment in a specialist centre familiar with these techniques is essential.
Modulation of central leptin sensitivity and energy balance in a rat model of diet‐induced obesity
Authors: Fam B. C. , Morris M. J. , Hansen M. J. , Kebede M. , Andrikopoulos S. , Proietto J. , Thorburn A. W.
Published: August 2006

Aim:  The aim of this study was to further explore the time‐dependent changes in leptin sensitivity using a rat model of dietary fat–induced obesity and to investigate the potential mechanisms governing these changes.

Methods:  We used male, adult Sprague‐Dawley rats that were fed either a standard laboratory chow diet (3% fat) or a high–saturated fat (HF) diet (60% fat) for 2 or 5 weeks. Energy balance (body weight, energy intake and energy expenditure); sensitivity to central leptin and central α‐melanin stimulating hormone (α‐MSH) administration and expression levels of hypothalamic ObRb, signal transducers and activators of transcription factor (STAT)‐3 phosphorylation, suppressor of cytokine signalling‐3 (SOCS‐3), proopiomelanocortin (POMC) processing hormones (prohormone convertase‐1 and prohormone convertase‐2) and neuropeptide Y (NPY) were measured.

Results:  After 2 weeks of feeding HF diet, there was an increase in total energy intake (TEI) but a reduction in food intake as measured by the mass of food ingested. Body weight at this time was not significantly different between the two diet groups; however, white adipose tissue (WAT) weight was significantly greater in the HF‐fed rats than in the chow‐fed rats. In addition, spontaneous physical activity levels were increased, but no changes were observed in resting energy expenditure. Furthermore, chow‐fed lean rats responded to central leptin administration by reducing the energy intake by ∼67 kJ compared with saline treatment (p < 0.05), while the HF‐fed diet‐induced obese (DIO) rats responded by reducing their energy intake by ∼197 kJ compared with saline treatment (p < 0.05). After 5 weeks of feeding HF diet, TEI remained significantly higher, body weight was significantly increased by 5% in the HF‐fed rats and WAT weight was significantly heavier in HF‐fed rats than in the chow‐fed lean rats. After leptin treatment, the chow‐fed lean rats reduced their energy intake by ∼97 kJ (p < 0.05); yet, leptin had no significant effect in the HF‐fed DIO rats. ObRb protein expression, STAT‐3 phosphorylation levels, content and messenger RNA (mRNA) expression of NPY, SOCS‐3 mRNA and protein expression and energy intake response to central α‐MSH administration were not altered after HF diet feeding.

Conclusion:  These results suggest that early in the course of HF diet–induced weight gain, there was a period of central leptin hypersensitivity, and as the obesity progresses, central leptin insensitivity develops. This insensitivity does not appear to be explained by a downregulation of ObRb protein levels, reduced leptin signalling, an increase in either SOCS‐3 or NPY expression or reduced function of the melanocortin system. The effect of an HF diet on other actions of leptin such as its effect on the endocannabinoid system should be investigated.
Revision of the fishfly genus Ctenochauliodes van der Weele (Megaloptera, Corydalidae)
Authors: Liu Xing Yue , Yang Ding
Published: August 2006

The first taxonomic revision and phylogenetic analysis of the Oriental fishfly genus Ctenochauliodes van der Weele, 1909 is presented. Except for C. punctulatus, where the male is unknown, all species of Ctenochauliodes and two outgroups (Archichauliodes chilensis Kimmins and Protochauliodes bullocki Flint) were scored for 24 adult morphological characters, 21 of which were obtained from the male genitalia. The monophyly of Ctenochauliodes is corroborated by a series of synapomorphic characters. The pectinate female antenna was proposed as a diagnostic character. Two main clades within Ctenochauliodes were found based on the present phylogenetic analysis. All 12 Ctenochauliodes species are keyed, described and illustrated, with five species new to science. Ctenochauliodes forcipatus Kimmins is a junior synonym of C. friedrichi Navás, and C. moganshanus Yang & Yang is a junior synonym of C. griseus Yang & Yang. All Ctenochauliodes species were recorded from southern China, including 11 endemic species. Hence, there is no doubt that southern China should be acknowledged as the distribution centre of Ctenochauliodes.
Encouraging Consensus‐Challenging Research in Universities*
Authors: McMullen Jeffery S. , Shepherd Dean A.
Published: August 2006

abstract Drawing from self‐efficacy theory and transcriptions of in‐depth interviews, we construct a conjoint experiment that we then administer to 54 tenure‐tracked assistant professors from two Research‐I universities in the United States. Findings from their 1728 nested decisions show that the administrative effectiveness of outcome expectations and time constraints in encouraging highly uncertain, consensus‐challenging research depends on the research self‐efficacy of scholars. As expected, we find that increases in anticipated credit are more effective at encouraging consensus‐challenging research when scholars perceive themselves to be highly competent in the line of research being pursued. Surprisingly, however, we also find that increases in both blame and time pressures are more discouraging of consensus‐challenging research when scholars perceive themselves to be highly competent in a research area. We conclude by discussing the findings and their implications for research and practice.
Components of CEO Transformational Leadership and Corporate Social Responsibility*
Authors: Waldman David A. , Siegel Donald S. , Javidan Mansour
Published: August 2006

abstract We use transformational leadership theory to explore the role of CEOs in determining the extent to which their firms engage in corporate social responsibility (CSR). We test this theory using data from 56 US and Canadian firms. CEO intellectual stimulation (but not CEO charismatic leadership) is found to be significantly associated with the propensity of the firm to engage in ‘strategic’ CSR, or those CSR activities that are most likely to be related to the firm's corporate and business‐level strategies. Thus, studies that ignore the role of leadership in CSR may yield imprecise conclusions regarding the antecedents and consequences of these activities. We also critique transformational leadership theory, in terms of its overemphasis on charismatic forms of leadership. This leads to a reconceptualization of transformational leadership, which emphasizes the intellectual stimulation component in the context of CSR.
Toward a Model of Organizational Co‐Evolution in Transition Economies
Authors: Suhomlinova Olga
Published: August 2006

abstract  The paper presents a model of organization–environment co‐evolution, which portrays the joint impact of organizational and environmental characteristics on organizational survival. The four organizational characteristics included in the model are: (a) control structure, (b) product strategy, (c) exchange strategy, and (d) distance to the market. The three environmental characteristics are: (a) control structures, (b) competitive structures, and (c) exchange structures. In line with the general co‐evolutionary approach, the model highlights the interrelationship between micro and meso level phenomena, specifically, between firm‐level adaptation and industry‐level selection of organizational forms. The paper focuses on transition economies and uses the empirical evidence from these economies to illustrate the model's potential. The model, however, is sufficiently general to be applied in other organizational environments.
Global Standardization of Organizational Forms and Management Practices? What New Institutionalism and the Business‐Systems Approach Can Learn from Each Other*
Authors: Tempel Anne , Walgenbach Peter
Published: August 2006

abstract The debate as to the effects of globalization on organizational forms and management practices is well known. Our paper focuses on two institutionalist traditions in organization theory which make a significant contribution to this discussion: new institutionalism and the business‐systems approach. Both emphasize the adaptation of organizations to their institutional environments but come to very different conclusions as to the global standardization of organizational forms and management practices. Our paper aims to move them beyond the convergence‐divergence dichotomy to account for signs of both global standardization and continued persistence of national differences. We do so by systematically comparing the two traditions, suggesting how they can be cross‐fertilized and developing an agenda for future empirical research. We also highlight that they cannot learn from each other on the issue of agency and point to structuration theory as a way in which they can integrate agency into their accounts of the global standardization debate.
Fasting – the ultimate diet?
Authors: Johnstone A. M.
Published: August 2006

Adult humans often undertake acute fasts for cosmetic, religious or medical reasons. For example, an estimated 14% of US adults have reported using fasting as a means to control body weight and this approach has long been advocated as an intermittent treatment for gross refractory obesity. There are unique historical data sets on extreme forms of food restriction that give insight into the consequences of starvation or semi‐starvation in previously healthy, but usually non‐obese subjects. These include documented medical reports on victims of hunger strike, famine and prisoners of war. Such data provide a detailed account on how the body adapts to prolonged starvation. It has previously been shown that fasting for the biblical period of 40 days and 40 nights is well within the overall physiological capabilities of a healthy adult. However, the specific effects on the human body and mind are less clearly documented, either in the short term (hours) or in the longer term (days). This review asks the following three questions, pertinent to any weight‐loss therapy, (i) how effective is the regime in achieving weight loss, (ii) what impact does it have on psychology? and finally, (iii) does it work long‐term?
International school‐based interventions for preventing obesity in children
Authors: Sharma M.
Published: August 2006

The purpose of this article was to review international (excluding the United States) school‐based interventions for preventing obesity in children published between 1999 and 2005. A total of 21 such interventions were found from Australia (1), Austria (1), Canada (1), Chile (1), France (1), Germany (3), Greece (1), New Zealand (1), Norway (1), Singapore (1) and the United Kingdom (9). The grade range of these interventions was from pre‐school to high school with the majority (17) from elementary schools. Nine of these interventions targeted nutrition behaviours followed by seven aiming to modify both physical activity and nutrition behaviours. Only five interventions in international settings were based on any explicit behavioural theory which is different than the interventions developed in the United States. Majority of the interventions (9) were one academic year long. It can be speculated that if the interventions are behavioural theory‐based, then the intervention length can be shortened. All interventions that documented parental involvement successfully influenced obesity indices. Most interventions (16) focused on individual‐level behaviour change approaches. Most published interventions (16) used experimental designs with at least 1‐year follow‐up. Recommendations from international settings for enhancing the effectiveness of school‐based childhood obesity interventions are presented.
Obesity, metabolic syndrome and sleep apnoea: all pro‐inflammatory states
Authors: Alam I. , Lewis K. , Stephens J. W. , Baxter J. N.
Published: August 2006

Obesity is associated with significant morbidity and mortality and is increasing in prevalence worldwide. Associated conditions include insulin resistance (IR), diabetes, hypertension and dyslipidaemia; a clustering of these has recently been termed as metabolic syndrome. Weight gain is a major predictor of the metabolic syndrome with waist circumference being a more sensitive indicator than body mass index as it reflects both abdominal subcutaneous adipose tissue and visceral adipose tissue (VAT). VAT has more metabolic activity and secretes a number of hormones and pro‐inflammatory cytokines which are linked with the metabolic abnormalities listed above. Central obesity also increases the risk of obstructive sleep apnoea syndrome (OSAS), where the sleep disordered breathing may also independently lead to/or exacerbate IR, diabetes and cardiovascular risk. The contribution of OSAS to the metabolic syndrome has been under‐recognized. The putative mechanisms by which OSAS causes or exacerbates these other abnormalities are discussed. We propose that activation of nuclear factor kappa B by stress hypoxia and/or by increased adipokines and free fatty acids released by excess adipose tissue is the final common inflammatory pathway linking obesity, OSAS and the metabolic syndrome both individually and, in many cases, synergistically.
BHAGAVAD GĪTĀ AS DUTY AND VIRTUE ETHICS
Authors: Gupta Bina
Published: August 2006

The paper examines the ethical conception of the most well‐known and much discussed Hindu text, the Bhagavad Gītā, in the context of the Western distinction between duty ethics and virtue ethics. Most of the materials published on the Gītā make much of its conception of duty; however, there is no systematic investigation of the notion of virtue in the Gītā. The paper begins with a discussion of the fundamental characteristics of virtue ethics, before undertaking a discussion of the conceptions of duty and virtue in the Gītā. The paper clearly demonstrates that (1) both duty and virtue coexist in the Gītā, and (2) the Gītā accords virtue an important place.
FRANK CONVERSATIONS
Authors: Dickens W. T.
Published: August 2006

I contend that Jews, Christians, and Muslims who seek peace should not be reluctant to acknowledge the existence of their sometimes profound disagreements, or to affirm the truth of their own beliefs and practices. Since this places me at odds with John Hick, I analyze his views, granting the strengths of his critical realism and arguing that his revisionist–pluralist theory of religion has significant limitations for interreligious dialogue. Since the veridical–pluralist alternative I propose facilitates rather than stifles disagreement, I examine three different conceptions of dialogue that acknowledge the importance of disputes among those searching for truth. I also discuss three virtues—honesty, empathy, and humility—whose cultivation would make us less likely to fail in our search for truth and the peace that is its sign and fruit.