bluuebunny/crossref_metadata_2025 huggingface dataset:
The RNA chaperone, Hfq, controls two luxR‐type regulators and plays a key role in pathogenesis and production of antibiotics in Serratia sp. ATCC 39006
Authors: Wilf Nabil M. , Williamson Neil R. , Ramsay Joshua P. , Poulter Simon , Bandyra Kasia J. , Salmond George P. C.
Published: August 2011

Serratia sp. ATCC 39006 (S39006) is a Gram‐negative bacterium that is virulent in plant (potato) and animal (Caenorhabditis elegans) models. It produces two secondary metabolite antibiotics, a prodigiosin and a carbapenem, and the exoenzymes, pectate lyase and cellulase. A complex regulatory network that includes quorum sensing (QS) controls production of prodigiosin. While many aspects of the regulation of the metabolites and exoenzymes are well understood, the potential role in this network of the RNA chaperone Hfq and dependent small regulatory RNAs has not been characterized. Hfq is an RNA chaperone involved in post‐transcriptional regulation that plays a key role in stress response and virulence in diverse bacterial species. To explore whether Hfq‐dependent processes might contribute to the regulation of antibiotic production we constructed an S39006 Δhfq mutant. Production of prodigiosin and carbapenem was abolished in this mutant strain, while production of the QS signalling molecule, butanoyl homoserine lactone (BHL), was unaffected. Using transcriptional fusions, we found that Hfq regulates the QS response regulators, SmaR and CarR. Additionally, exoenzyme production and swimming motility were decreased in a Δhfq mutant, and virulence was attenuated in potato and C. elegans models. These results suggest that an Hfq‐dependent pathway is involved in the regulation of virulence and secondary metabolite production in S39006.
Foetal proglucagon processing in relation to adult appetite control: lessons from a transplantable rat glucagonoma with severe anorexia
Authors: Jensen P. B. , Larsen P. J. , Karlsen C. , Jensen H. I. , Holst J. J. , Madsen O. D.
Published: August 2011

We have previously reported severe anorexia abruptly induced in rats 2–3 weeks after they have been transplanted subcutaneously with the glucagonoma MSL‐G‐AN. Vagotomy did not affect the time of onset and severity of anorexia, and the anorectic state resembles hunger with strongly elevated neuropeptide Y (NPY) mRNA levels in the nucleus arcuatus. We now show that circulating levels of bioactive glucagon‐like peptide‐1 (GLP‐1) (7‐36amide) start to increase above control levels exactly at the time of onset of anorexia. At this time‐point, bioactive glucagon as well as total glucagon precursors and GLP‐1 metabolites are already vastly elevated compared to controls. We further show that intravenous administration of very high concentrations of GLP‐1 to hungry schedule‐fed rats causes anorexia in a dose‐dependent manner, which is blocked by the GLP‐1 receptor antagonist exendin (9‐39). GLP‐1 (7‐36amide) has a well‐characterized anorectic effect but also causes taste aversion when administered centrally. The anorectic effect is blocked in rats treated neonatally by monosodium glutamate (MSG). We show that MSG treatment does not prevent the MSL‐G‐AN‐induced anorexia, thereby suggesting a different type of anorectic function. We show a very strong component of taste aversion as anorectic rats, when presented to novel or known alternative food items, will resume normal feeding for 1 day, and then redevelop anorexia. We hypothetize that the anorexia in MSL‐G‐AN tumour‐bearing rats correlates with a foetal processing pattern of proglucagon to both glucagon and GLP‐1 (7‐36amide), and is due to taste aversion. The sudden onset is characterized by a dramatic increase in circulating levels of biologically active GLP‐1 (7‐36amide), suggesting eventual saturation of proteolytic inactivation of its N‐terminus.
Growth factor signalling in the regulation of α‐cell fate
Authors: Kawamori D. , Akiyama M. , Hu J. , Hambro B. , Kulkarni R. N.
Published: August 2011

Glucagon plays critical roles in regulating glucose homeostasis, mainly by counteracting the effects of insulin. Consequently, the dysregulated glucagon secretion that is evident in type 2 diabetes has significant implications in the pathophysiology of the disease. Glucagon secretion from pancreatic α‐cells has been suggested to be modulated by blood glucose, signals from the nervous system and endocrine components. In addition to these regulators, intraislet factors acting in a paracrine manner from neighbouring β‐cells are emerging as central modulator(s) of α‐cell biology. One of the most important of these paracrine factors, insulin, modulates glucagon secretion. Indeed, the α‐cell‐specific insulin receptor knockout (αIRKO) mouse manifests hypersecretion of glucagon in the postprandial stage and exhibits defective secretion in fasting‐induced hypoglycaemia, together mimicking the α‐cell defects observed in type 2 diabetes. Interestingly, αIRKO mice display a progressive increase in β‐cell mass and a concomitant decrease in α‐cells. Lineage trace analyses reveal that the new β‐cells originate, in part, from the insulin receptor‐deficient α‐cells indicating a critical role for α‐cell insulin signalling in determining β‐cell origin. Our studies also reveal that glucagon‐like peptide‐1 (GLP‐1) treatment of αIRKO mice suppresses glucagon secretion despite absence of functional insulin receptors precluding a role for insulin in GLP‐1 action on α‐cells in this model. These findings highlight the significance of insulin signalling in the regulation of α‐cell biology.
Reprogramming gut and pancreas endocrine cells to treat diabetes
Authors: Tudurí E. , Kieffer T. J.
Published: August 2011

Multiple approaches have been investigated with the ultimate goal of providing insulin independence to patients with either type 1 or type 2 diabetes. Approaches to produce insulin‐secreting cells in culture, convert non‐β‐cells into functional β‐cells or engineer autologous cells to express and secrete insulin in a meal‐responsive manner have all been described. This research has been facilitated by significant improvements in both viral and non‐viral gene delivery approaches that have enabled new experimental strategies. Many studies have examined possible avenues to confer islet cytoprotection against immune rejection, inflammation and apoptosis by genetic manipulation of islet cells prior to islet transplantation. Here we review several reports based on the reprogramming of pancreas and gut endocrine cells to treat diabetes.
A role for zinc in pancreatic islet β‐cell cross‐talk with the α‐cell during hypoglycaemia
Authors: Robertson R. P. , Zhou H. , Slucca M.
Published: August 2011

Signalling by intraislet β‐cells to neighbouring α‐cells was recognized almost 40 years ago, leading to the hypothesis that this is an essential mechanism to regulate the glucagon counterregulatory response to hypoglycaemia. The thesis was that during normoglycaemia or hyperglycaemia insulin secretion from β‐cells would enter the islet periportal circulation and travel downstream to α‐cells to dampen glucagon secretion. As a corollary, during hypoglycaemia β‐cells would stop secreting insulin, which would permit α‐cells to release glucagon into the hepatic portal circulation so it could travel to the liver to increase glucose production and thereby correct hypoglycaemia. This mini‐review briefly mentions the early work that established this hypothesis and more extensively examines more recent work that has provided direct evidence supporting the hypothesis. A new twist has been introduced based on the fact that zinc is bound to insulin within β‐cells and co‐secreted with insulin. Zinc is released from insulin when it reaches the higher pH of blood, and zinc has recently been shown to negatively regulate α‐cell secretion. It is now suggested that a switch‐off signal provided by a sudden cessation of zinc secretion from β‐cells during hypoglycaemia may play a critical role in stimulating glucagon secretion that is independent of the effect of insulin.
Regulation of glucagon secretion by incretins
Authors: Holst J. J. , Christensen M. , Lund A. , de Heer J. , Svendsen B. , Kielgast U. , Knop F. K.
Published: August 2011

Glucagon secretion plays an essential role in the regulation of hepatic glucose production, and elevated fasting and postprandial plasma glucagon concentrations in patients with type 2 diabetes (T2DM) contribute to their hyperglycaemia. The reason for the hyperglucagonaemia is unclear, but recent studies have shown lack of suppression after oral but preserved suppression after isoglycaemic intravenous glucose, pointing to factors from the gut. Gastrointestinal hormones that are secreted in response to oral glucose include glucagon‐like peptide‐1 (GLP‐1) that strongly inhibits glucagon secretion, and GLP‐2 and GIP, both of which stimulate secretion. When the three hormones are given together on top of isoglycaemic intravenous glucose, glucagon suppression is delayed in a manner similar to that observed after oral glucose. Studies with the GLP‐1 receptor antagonist, exendin 9–39, suggest that endogenous GLP‐1 plays an important role in regulation of glucagon secretion during fasting as well as postprandially. The mechanisms whereby GLP‐1 regulates glucagon secretion are debated, but studies in isolated perfused rat pancreas point to an important role for a paracrine regulation by somatostatin from neighbouring D cells. Clinical studies of the antidiabetic effect of GLP‐1 in T2DM suggest that the inhibition of glucagon secretion is as important as the stimulation of insulin secretion.
Morphology of retinal vessels in the optic disk in a Göttingen minipig experimental glaucoma model
Authors: Galdos Marta , Bayón Alejandro , Rodriguez Francisco D. , Micó Carlos , Sharma Sansar C. , Vecino Elena
Published: August 2011

Objective  To compare the morphology of normal, healthy Gottingen minipig retinal vessels of the optic disk with experimentally induced glaucomatous optic disks in order to identify the glaucomatous excavation. Present results were compared to human glaucoma findings.

Procedure  Sixteen eyes from eight Göttingen minipigs were studied using fundoscopic photography and fluorescein angiography. Experimental glaucoma was then induced in the left eyes over 14 months, and changes in the optic disk vessels were assessed using fundoscopic photography and fluorescein angiography. The changes were compared with those previously reported in humans.

Results  Regarding the number of vessels, the location from where they emerge and the sectors of the optic disk that they cross, arterial and retinal vessels in Göttingen minipigs present a more asymmetric layout than in humans. The central excavation is filled by the central venous ring. Changes in the glaucomatous optic disk include arteriolar incurvation, and sometimes, nasal, and peripheral displacement of the arterioles that emerge between the ganglion cell axons of the neuroretinal ring. No angiographic changes were observed in the experimental glaucoma model.

Conclusions  The changes in the glaucomatous optic disk of the minipig imply a predominant involvement of the arterioles. However, in humans with primary open‐angle glaucoma (POAG), both the arterioles and the venules are displaced, and the central excavation is easier to distinguish, because of the absence of a central venous ring.
Conjunctivitis and ulcerative keratitis secondary to conjunctival plant foreign bodies in a herd of alpacas (Lama Pacos)
Authors: Fischer Kristin , Hendrix Diane
Published: August 2011

Purpose To describe six cases of conjunctivitis and ulcerative keratitis secondary to plant foreign bodies from weed‐contaminated grass hay which were lodged within the temporal conjunctival fornix in a herd of alpacas.

Methods A total of 21 alpacas from the same farm developed blepharospasm and mucopurulent ocular discharge. Six of the 21 were evaluated at the University of Tennessee College of Veterinary Medicine within a 2‐week period. The six animals evaluated received an ophthalmic examination including slit‐lamp biomicroscopy, fluorescein staining, and topical corneal anesthesia for foreign body removal when necessary.

Results Six animals had conjunctivitis characterized by hyperemia and mucopurulent discharge. Five animals had superficial ulcerative keratitis with intense corneal neovascularization and edema. In all cases, the keratitis was located at the temporal limbus. Seven plant foreign bodies were observed and were removed following topical corneal anesthesia in five animals. The plant seeds were identified as three common weed species found in orchard grass hay. Complete resolution of all clinical signs was achieved with foreign body removal and medical therapy.

Conclusions Fan‐shaped temporal corneal ulcers may signify the presence of conjunctival foreign bodies in alpacas. Plant foreign bodies should be considered in addition to ocular infection when multiple animals of a herd are affected as outbreaks may occur with weed‐contaminated hay.
Liberal vs. Republican Notions of Freedom
Authors: Shnayderman Ronen
Published: August 2011

One of the most interesting current debates about the ideal of freedom is the debate between the adherents of the recently revived republican notion of negative freedom, most notably Quentin Skinner and Philip Pettit, and the adherents of the prevailing liberal notion of negative freedom, most notably Ian Carter and Matthew Kramer. The debate between these two parties concerns the question of what negative freedom is. While Carter and Kramer argue that negative freedom is simply the absence of interference, Skinner and Pettit argue that negative freedom is first and foremost the absence of arbitrary power to interfere (or, in short, domination) and only in a secondary sense also the absence of interference. In this article I argue that the republican notion of negative freedom is implausible, since it entails that situations involving only domination are as inimical to negative freedom as situations involving both domination and dominating interference; and, moreover, that Pettit and Skinner themselves find the idea that these two situations are equally inimical to negative freedom implausible.
When Is a Country Multinational? Problems with Statistical and Subjective Approaches*
Authors: STOJANOVIC NENAD
Published: August 2011

Many authors have argued that we should make a clear conceptual distinction between mononational and multinational states. Yet the number of empirical examples they refer to is rather limited. France or Germany are usually seen as mononational, whereas Belgium, Canada, Spain and the UK are considered multinational. How should we classify other cases? Here we can distinguish between (at least) two approaches in the literature: statistical (i.e., whether significant national minorities live within a larger state and, especially, whether they claim self‐government) and subjective (i.e., when citizens feel allegiance to sub‐state national identities). Neither of them, however, helps us to resolve the problem. Is Italy multinational (because it contains a German‐speaking minority)? Is Germany really mononational (in spite of the official recognition of the Danes and the Sorbs in someLänder)? On the other hand, is Switzerland the “most multinational country” (Kymlicka)? Let us assume that there is no definite answer to this dilemma and that it is all a matter of degree. There are probably few (if any) clearly mononational states and few (if any) clearly multinational states. Should we abandon this distinction in favour of other concepts like “plurinationalism” (Keating), “nations‐within‐nations” (Miller), “postnational state” (Abizadeh, Habermas), or “post‐sovereign state” (MacCormick)? The article discusses these issues and, in conclusion, addresses the problem of stability and shared identity “plural” societies.
Market intermediaries and rural people in Bolivia's forest products sector: Are trusting partnerships possible?
Authors: Murphy James T. , Lawhon Mary
Published: August 2011

Decentralization in access to and control of Bolivia's forest resources, coupled with a rising global demand for tropical hardwoods, raises important questions about whether increased trade and community forest management (CFM) initiatives can enable forms of market integration that have more favourable outcomes for rural communities. This paper assesses the prospects for such a transition through an examination of the relationships linking wood product market intermediaries (brokers and buyers) to rural suppliers and forest communities in Bolivia. The analysis centres on whether trust – conceptualized as a power‐laden sociospatial process driven by multiscalar factors – can evolve between buyers and suppliers such that more progressive (sustainable and mutually beneficial) partnerships devolop. Focusing on three types of buyer–supplier relationships in Bolivia – direct ties between wood brokers/buyers and suppliers, nongovernmental organization (NGO) mediated exchange relationships and Forest Stewardship Council (FSC) certification of suppliers – our findings show how trust building initiatives that focus on one scale may fail if factors at other scales create obstacles to collaboration, Given these relational constraints, CFM strategies in Bolivia currently face limitation on their viability as economic development strategies.
Cervical intraepithelial neoplasia and invasive cancer risks in women infected with HIV in the French West Indies
Authors: Kadhel P , Multigner L , Bardinet F , Goerger‐Sow MT , Janky E
Published: August 2011

Objective

The aim of the study was to assess whether HIV infection is associated with a higher risk of invasive cervical cancer (ICC).

Methods

We conducted a region‐wide, population‐based observational cohort study of 1232 HIV‐infected women over the age of 15 years in Guadeloupe, a French Caribbean archipelago, during the period 1999–2006. The observed numbers of incident cases of cervical intraepithelial neoplasia (CIN) and ICC were compared with the expected numbers of cases based on the incidence rates for the general population, and the standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated.

Results

The incidence rate of CIN was higher in the HIV‐infected women than in the general population for all grades (SIR 10.1, 95% CI 6.8–14.6 for CIN grade 1; SIR 9.9, 95% CI 6.1–15.3 for CIN grade 2; and SIR 5.2, 95% CI 3.4–7.7 for CIN grade 3). However, no increase in the risk of ICC was observed (SIR 1.7, 95% CI 0.3–4.9).

Conclusions

Despite an increase in the occurrence of cervical cancer precursors, no increase in the risk of cervical cancer was found in a population of HIV‐infected women who receive treatment for their infection and have access to ICC prevention services.
The effect of injecting drug use history on disease progression and death among HIV‐positive individuals initiating combination antiretroviral therapy: collaborative cohort analysis
Authors: Murray M , Hogg RS , Lima VD , May MT , Moore DM , Abgrall S , Bruyand M , D'Arminio Monforte A , Tural C , Gill MJ , Harris RJ , Reiss P , Justice A , Kirk O , Saag M , Smith CJ , Weber R , Rockstroh J , Khaykin P , Sterne JAC ,   for the Antiretroviral Therapy Cohort Collaboration (ART‐CC)
Published: August 2011

Background

We examined whether determinants of disease progression and causes of death differ between injecting drug users (IDUs) and non‐IDUs who initiate combination antiretroviral therapy (cART).

Methods

The ART Cohort Collaboration combines data from participating cohort studies on cART‐naïve adults from cART initiation. We used Cox models to estimate hazard ratios for death and AIDS among IDUs and non‐IDUs. The cumulative incidence of specific causes of death was calculated and compared using methods that allow for competing risks.

Results

Data on 6269 IDUs and 37 774 non‐IDUs were analysed. Compared with non‐IDUs, a lower proportion of IDUs initiated cART with a CD4 cell count <200 cells/μL or had a prior diagnosis of AIDS. Mortality rates were higher in IDUs than in non‐IDUs (2.08 vs. 1.04 per 100 person‐years, respectively; P<0.001). Lower baseline CD4 cell count, higher baseline HIV viral load, clinical AIDS at baseline, and later year of cART initiation were associated with disease progression in both groups. However, the inverse association of baseline CD4 cell count with AIDS and death appeared stronger in non‐IDUs than in IDUs. The risk of death from each specific cause was higher in IDUs than non‐IDUs, with particularly marked increases in risk for liver‐related deaths, and those from violence and non‐AIDS infection.

Conclusion

While liver‐related deaths and deaths from direct effects of substance abuse appear to explain much of the excess mortality in IDUs, they are at increased risk for many other causes of death, which may relate to suboptimal management of HIV disease in these individuals.
Psodisk, a new visual method for assessing the burden of psoriasis on patients
Authors: Linder D. , Sampogna F. , Torreggiani A. , Balato N. , Bianchi L. , Cassano N. , Conti A. , Gisondi P. , Musumeci M.L. , Piaserico S. , Potenza C. , Romano G.V. , di Luzio Paparatti U.
Published: August 2011

Background  The last decades have witnessed an increasing interest for the psychosocial aspects of chronic skin diseases, such as psoriasis. Nonetheless, systematic assessments of the impact of psoriasis on patients’ lives are rarely done in daily clinical practice. The existing instruments are mostly meant to be completed by patients alone, and rarely comprise a graphical representation of the results.

Objective  To develop a questionnaire allowing both a quick assessment of the impact of psoriasis on patients and, at the same time, an intuitive graphic visualization of the outcome of the test.

Methods  A preliminary version of an Italian questionnaire aimed to assess the global impact of psoriasis on patients, meant to be filled in together by the patient and the dermatologist and to produce visual, intuitive results, was developed through focus groups. The instrument was then the object of a Delphi survey addressed to a panel of experts, to assess both the need of possible improvements of the questionnaire (in terms of the formulations of the questions and of the domains to be explored) and the usefulness of the questionnaire.

Results  A 10‐item questionnaire in Italian, taking into account different aspects of the burden of psoriasis on the patient, was developed. The answers are given on a 10‐point visual analogue scale and graphically represented on a disc as a polygon.

Conclusions  A formal validation of the questionnaire and a study to assess potential clinical and psychological benefits of a systematic implementation of the instrument in daily practice are planned.
Treatment of epidermolysis bullosa acquisita with intravenous immunoglobulin in patients non‐responsive to conventional therapy: clinical outcome and post‐treatment long‐term follow‐up
Authors: Ahmed A.R. , Gürcan H.M.
Published: August 2011

Background  Epidermolysis bullosa acquisita (EBA) is a chronic subepidermal blistering disease that is caused by antibodies binding to type VII collagen within anchoring fibrils. It is rare disease with an incidence of 0.25 cases per 1 000 000 population.

Objective  The objective of this study is to report the treatment outcomes with intravenous immunoglobulin (IVIg) therapy in 10 patients with severe and widespread EBA non‐responsive to conventional therapy.

Methods  Patients were treated according to a protocol published in a Consensus Statement to treat autoimmune mucocutaneous blistering diseases, including EBA with IVIg. A dose of 2 g/kg/cycle was used.

Results  Ten patients: four males and six females, all were North American Caucasian. The age at onset varied from 37 to 75 years (mean 57.4). A satisfactory clinical response was observed in all 10 patients. The patients received 16–31 cycles (mean 23.1) of IVIg over a period of 30–52 months (mean 38.8). Once IVIg was initiated, earlier drugs (prednisone, dapsone and others) were gradually withdrawn over a 5–9 month period (mean 7.2). Thereafter, IVIg was used as monotherapy. No serious side‐effects were observed. The follow‐up period since discontinuation of IVIg varied from 29 to 123 months (mean 53.9). During this follow‐up period, recurrence of disease was not observed.

Conclusion  The data suggest that IVIg can produce a long‐term sustained clinical remission in patients with EBA. In the patients, of this study concomitant therapy could be discontinued and IVIg was used as monotherapy.
Inefficient Investment and the Diversification Discount: Evidence from Corporate Asset Purchases
Authors: Chen Sheng‐Syan , Chen I‐Ju
Published: August 2011

Abstract:  We provide evidence that investment efficiency considerations are important in assessing changes in firm value surrounding asset purchases. We account for both the potential endogeneity in purchase decisions and the measurement error in Tobin's q. We find that post‐purchase, there are significant declines in both excess value and investment efficiency. This trend occurs primarily among those firms that demonstrate increased diversity following purchases. The change in excess value for diversity‐increasing buyers is positively related to the change in investment allocation surrounding the purchase.
Ontogeny of feeding performance and biomechanics in coyotes
Authors: La Croix S. , Zelditch M. L. , Shivik J. A. , Lundrigan B. L. , Holekamp K. E.
Published: August 2011

Developing organisms must reconcile conflicts between demands of survival within the current life‐history stage, with those of maturation, while negotiating the transitions through succeeding stages. In the case of feeding performance, the parts of the feeding apparatus and their biomechanics must maintain functional integrity to meet the feeding needs of a juvenile even as they develop toward their adult form. We concurrently examine the ontogenetic relationships of feeding performance, dentition and feeding biomechanics, relative to key life‐history events, utilizing samples drawn from the same population of known‐age coyotes Canis latrans. The development of feeding performance is asynchronous with development of both feeding biomechanics and skull morphology; feeding performance lags during ontogeny despite surprisingly large early mechanical advantage of the temporalis, due in part, to early relative maturity of mandibular shape. Feeding performance and biomechanics, like skull morphology, mature well after weaning at 6 weeks of age. Late maturation of bite strength and feeding performance is mediated by ongoing and continued growth of the temporalis muscles as measured by maximum zygomatic arch breadth (ZAB). Males and females may resolve developmental conflicts differently, as females trade earlier maturity for smaller maximum ZAB, decreased relative bite strength and diminished feeding performance, compared with males. The asynchrony of feeding performance development seen in coyotes, is also characteristic of a highly specialized carnivore, the spotted hyena, but coyotes have a much less protracted development, being handicapped relative to adults for a much shorter time. This developmental asynchrony between feeding performance and morphology suggests that a certain minimum threshold of physical growth and development, together with the associated development of biomechanics, are required to produce effective mastication. The relationships among biomechanics, life‐history schedules and ontogeny of feeding performance have obvious implications for fitness.
Consequences of compensatory growth in an amphibian
Authors: Hector K. L. , Bishop P. J. , Nakagawa S.
Published: August 2011

Compensatory growth, or catch‐up growth, occurs when an organism grows faster than the optimal rate after a period of growth restriction. The evolved optimal growth rate maximizes an animal's fitness potential while preserving tissue quality. Rapid compensatory growth allows the organism to achieve an adult size closer to that of an unrestricted conspecific. However, this accelerated growth may come at the cost of impaired fitness later in life due to accumulated cellular damage. Amphibians are an interesting, yet neglected, group in which to observe the effects of compensatory growth because of their flexible life history and the importance of large size for reproductive fitness. We investigated the effects of early nutritional restriction on the growth, morphology and three fitness‐related behavioural traits of brown tree frog tadpoles Litoria ewingii before and after metamorphosis. Tadpoles were fed reduced rations for two weeks, c. 35% of the control group's larval period, before being returned to the diet of the controls. The dietary treatment caused a significant difference in pre‐ and post‐metamorphic survival between the groups. The tadpoles on the restricted diet exhibited faster weight gain upon refeeding and reached a final size significantly larger than the control tadpoles. However, the larval period of the restricted group was extended by c. 5 days, compared with the control group. Early nutritional restriction also negatively affected the pre‐metamorphic fitness‐related behavioural trait of swimming speed. The restricted group showed an unexpected advantage in both post‐metamorphic fitness‐related behavioural traits of feeding latency and hopping ability. These results contrast with previous work on compensatory growth in tadpoles because nutritional restriction affected the developmental rate and also resulted in ‘over‐compensation’ of growth. Our experiment provides support for the prevalence of compensatory growth in diverse taxa and a unique observation of the post‐metamorphic consequences in amphibians adapted to ephemeral environments.
Neurophysiological markers of retrieval‐induced forgetting in multiplication fact retrieval
Authors: Galfano Giovanni , Penolazzi Barbara , Fardo Francesca , Dhooge Elisah , Angrilli Alessandro , Umiltà Carlo
Published: August 2011

Event‐related potential (ERP) counterparts of practice effects in multiplication fact retrieval were examined. Participants performed a multiplication verification task after having practiced a specific problem set. Practice was either active (retrieval of solutions to multiplication problems) or passive (reexposure to the same operands plus the correct result). Behavioral data showed retrieval‐induced facilitation for practiced items and retrieval‐induced forgetting for related, unpracticed items, irrespective of practice type. ERPs revealed that, for the active practice group, forgetting was reflected in a reduced N100 component time‐locked to result onset. Irrespective of practice type, forgetting was also reflected in a reduced result‐locked P350 component, whereas facilitation was associated with an increased amplitude of the same component. These results suggest that beneficial and detrimental effects of practice may be mediated by partially distinct processes.
In the face of fear: Anxiety sensitizes defensive responses to fearful faces
Authors: Grillon Christian , Charney Danielle R.
Published: August 2011

Fearful faces readily activate the amygdala. Yet, whether fearful faces evoke fear is unclear. Startle studies show no potentiation of startle by fearful faces, suggesting that such stimuli do not activate defense mechanisms. However, the response to biologically relevant stimuli may be sensitized by anxiety. The present study tested the hypothesis that startle would not be potentiated by fearful faces in a safe context, but that startle would be larger during fearful faces compared to neutral faces in a threat‐of‐shock context. Subjects viewed fearful and neutral faces in alternating periods of safety and threat of shock. Acoustic startle stimuli were presented in the presence and absence of the faces. Startle was transiently potentiated by fearful faces compared to neutral faces in the threat periods. This suggests that although fearful faces do not prompt behavioral mobilization in an innocuous context, they can do so in an anxiogenic one.
Alpha modulation in parietal and retrosplenial cortex correlates with navigation performance
Authors: Chiu Te‐Cheng , Gramann Klaus , Ko Li‐Wei , Duann Jeng‐Ren , Jung Tzyy‐Ping , Lin Chin‐Teng
Published: August 2011

The present study investigated the brain dynamics accompanying spatial navigation based on distinct reference frames. Participants preferentially using an allocentric or an egocentric reference frame navigated through virtual tunnels and reported their homing direction at the end of each trial based on their spatial representation of the passage. Task‐related electroencephalographic (EEG) dynamics were analyzed based on independent component analysis (ICA) and subsequent clustering of independent components. Parietal alpha desynchronization during encoding of spatial information predicted homing performance for participants using an egocentric reference frame. In contrast, retrosplenial and occipital alpha desynchronization during retrieval covaried with homing performance of participants using an allocentric reference frame. These results support the assumption of distinct neural networks underlying the computation of distinct reference frames and reveal a direct relationship of alpha modulation in parietal and retrosplenial areas with encoding and retrieval of spatial information for homing behavior.
Debating Latin American Aesthetic Theory. Beatriz Sarlo on the Autonomy of Art
Authors: POPOVITCH ANNA
Published: August 2011

For quite some time, Beatriz Sarlo has been at the forefront of the debate over the possibility of ascertaining the aesthetic value of art. The Argentine critic's dismissal of value‐neutral approaches to art has been often criticised as a repackaging of the aestheticist tradition inherited from the European Enlightenment. Using Sarlo's own critical practice – a selection of Sarlo's key texts on Argentine literature written since 1980 – as a testing ground for her theoretical insights I argue in favour of re‐evaluating Sarlo's project as an aporetic discourse with positive implications for cultural politics that should be refined rather than abandoned.
Is Inequality Becoming Just? Changes in Public Opinion about Economic Distribution in Chile
Authors: CASTILLO JUAN CARLOS
Published: August 2011

Chile is one of the few Latin American countries that has participated in the inequality module of the International Social Survey Program (ISSP) in 1999 and in 2009, allowing time comparisons in attitudes towards inequality in one of the countries with the highest income inequality throughout the world. This paper focuses on the cross‐sectional comparison of the just earning gap, a proportional term based on salaries considered just for high and low status occupations. Even though descriptive analysis shows that the salary gap regarded as just is higher in 2009 than in 1999, explanatory models give evidence of stability over time. Results are discussed in relation to phenomena of legitimacy of economic inequality and its political consequences.
A human IgM signals axon outgrowth: coupling lipid raft to microtubules
Authors: Xu Xiaohua , Warrington Arthur E. , Wright Brent R. , Bieber Allan J. , Van Keulen Virginia , Pease Larry R. , Rodriguez Moses
Published: August 2011

J. Neurochem. (2011) 119, 100–112.

Mouse and human IgMs support neurite extension from primary cerebellar granule neurons. In this study using primary hippocampal and cortical neurons, we demonstrate that a recombinant human IgM, rHIgM12, promotes axon outgrowth by coupling membrane domains (lipid rafts) to microtubules. rHIgM12 binds to the surface of neuron and induces clustering of cholesterol and ganglioside GM1. After cell binding and membrane fractionation, rHIgM12 gets segregated into two pools, one associated with lipid raft fractions and the other with the detergent‐insoluble cytoskeleton‐containing pellet. Membrane‐bound rHIgM12 co‐localized with microtubules and co‐immuno precipitated with β3‐tubulin. rHIgM12‐membrane interaction also enhanced the tyrosination of α‐tubulin indicating a stabilization of new neurites. When presented as a substrate, rHIgM12 induced axon outgrowth from primary neurons. We now demonstrate that a recombinant human mAb can induce signals in neurons that regulate membrane lipids and microtubule dynamics required for axon extension. We propose that the pentameric structure of the IgM is critical to cross‐link membrane lipids and proteins resulting in signaling cascades.
The evolution and phylogenetic placement of invasive Australian Acacia species
Authors: Miller Joseph T. , Murphy Daniel J. , Brown Gillian K. , Richardson David M. , González‐Orozco Carlos E.
Published: August 2011

Aim  Acacia is the largest genus of plants in Australia with over 1000 species. A subset of these species is invasive in many parts of the world including Africa, the Americas, Europe, the Middle East, Asia and the Pacific region. We investigate the phylogenetic relationships of the invasive species in relation to the genus as a whole. This will provide a framework for studying the evolution of traits that make Acacia species such successful invaders and could assist in screening other species for invasive potential.

Location  Australia and global.

Methods  We sequenced four plastid and two nuclear DNA regions for 110 Australian Acacia species, including 16 species that have large invasive ranges outside Australia. A Bayesian phylogenetic tree was generated to define the major lineages of Acacia and to determine the phylogenetic placement of the invasive species.

Results  Invasive Acacia species do not form a monophyletic group but do form small clusters throughout the phylogeny. There are no taxonomic characters that uniquely describe the invasive Acacia species.

Main conclusions  The legume subfamily Mimosoideae has a high percentage of invasive species and the Australian Acacia species have the highest rate of all the legumes. There is some evidence of phylogenetic clumping of invasive species of Acacia in the limited sampling presented here. This phylogeny provides a framework for further testing of the evolution of traits associated with invasiveness in Acacia.
Creating novel food webs on introduced Australian acacias: indirect effects of galling biological control agents
Authors: Veldtman Ruan , Lado Thomas F. , Botes Antoinette , Procheş Şerban , Timm Alicia E. , Geertsema Henk , Chown Steven L.
Published: August 2011

Aim  The use of host‐specific biological control agents is widely considered an effective option for the management of invasive alien plant species. However, the formation of novel associations between released biological control agents and indigenous species poses risks. Here, we investigate whether native food webs associated with two galling biological control agents on Acacia longifolia and A. saligna are similar to those found in their introduced range.

Location  Gall inhabitants recorded from South Africa and Australia.

Methods  Non‐targeted insects were collected from galls in introduced ranges for comparisons to that of the agents’ native ranges.

Results  We find that two host plant‐specific galling biological control agents accumulate food web links with higher trophic levels in their introduced range that are similar in number, taxonomic/phylogenetic pattern and guild composition to those in their native range. Bray‐Curtis percentage similarity between native (Australia) and novel (South Africa) food webs was 30–50% and 50–75% at the family and superfamily taxonomic level, respectively, and 45–50% if considering shared phylogenetic diversity.

Main conclusions  Trichilogaster acaciaelongifoliae and Uromycladium tepperianum accumulated food webs in South Africa that are strikingly similar in complexity and structure to those that occur in their native ranges. This indicates that the structure of food webs in the introduced range could be predicted by studying food webs in the native range of a biological control agent, potentially paving the way for more effective risk assessment of weed biological control.
Contain or eradicate? Optimizing the management goal for Australian acacia invasions in the face of uncertainty
Authors: Moore Joslin L. , Runge Michael C. , Webber Bruce L. , Wilson John R. U.
Published: August 2011

Aim  To identify whether eradication or containment is expected to be the most cost‐effective management goal for an isolated invasive population when knowledge about the current extent is uncertain.

Location  Global and South Africa.

Methods  We developed a decision analysis framework to analyse the best management goal for an invasive species population (eradication, containment or take no action) when knowledge about the current extent is uncertain. We used value of information analysis to identify when investment in learning about the extent will improve this decision‐making and tested the sensitivity of the conclusions to different parameters (e.g. spread rate, maximum extent, and management efficacy and cost). The model was applied to Acacia paradoxa DC, an Australian shrub with an estimated invasive extent of 310 ha on Table Mountain, South Africa.

Results  Under the parameters used, attempting eradication is cost‐effective for infestations of up to 777 ha. However, if the invasion extent is poorly known, then attempting eradication is only cost‐effective for infestations estimated as 296 ha or smaller. The value of learning is greatest (maximum of 8% saving) when infestation extent is poorly known and if it is close to the maximum extent for which attempting eradication is optimal. The optimal management action is most sensitive to the probability that the action succeeds (which depends on the extent), with the discount rate and cost of management also important, but spread rate less so. Over a 20‐year time‐horizon, attempting to eradicate A. paradoxa from South Africa is predicted to cost on average ZAR 8 million if the extent is known, and if our current estimate is poor, ZAR 33.6 million as opposed to ZAR 32.8 million for attempting containment.

Main conclusions  Our framework evaluates the cost‐effectiveness of attempting eradication or containment of an invasive population that takes uncertainty in population extent into account. We show that incorporating uncertainty in the analysis avoids overly optimistic beliefs about the effectiveness of management enabling better management decisions. For A. paradoxa in South Africa, attempting to eradicate is likely to be cost‐effective, particularly if resources are allocated to better understand and improve management efficacy.
Human‐mediated introductions of Australian acacias – a global experiment in biogeography
Authors: Richardson David M. , Carruthers Jane , Hui Cang , Impson Fiona A. C. , Miller Joseph T. , Robertson Mark P. , Rouget Mathieu , Le Roux Johannes J. , Wilson John R. U.
Published: August 2011

Aim  Australian acacias (1012 recognized species native to Australia, which were previously grouped in Acacia subgenus Phyllodineae) have been moved extensively around the world by humans over the past 250 years. This has created the opportunity to explore how evolutionary, ecological, historical and sociological factors interact to affect the distribution, usage, invasiveness and perceptions of a globally important group of plants. This editorial provides the background for the 20 papers in this special issue of Diversity and Distributions that focusses on the global cross‐disciplinary experiment of introduced Australian acacias.

Location  Australia and global.

Methods  The papers of the special issue are discussed in the context of a unified framework for biological invasions. Distributions of species were mapped across Australia, their representation in bioclimatic zones examined and the potential global distribution of the group modelled. By collating a variety of different lists, we determined which Australian acacias have reached different stages in the introduction‐naturalization‐invasion continuum in different parts of the world. Paradigms and key research questions relating to barriers to invasion, stages of invasion and management perceptions are sketched.

Results  According to our global database of Australian acacia records, 386 species have been moved outside Australia by human agency, 71 species are naturalized or weedy, and 23 are unequivocally invasive. Climatic models suggest that about a third of the world’s land surface is climatically suitable for Australian acacias. Many species are commercially important crops or are useful for other purposes and have been extensively planted, and many different human perceptions of Australian acacias exist in different parts of the world. The papers in the special issue cover all the barriers, stages and processes that define biological invasions and touch on many aspects: history and the human dimension; aspects of the species pool; species traits; biotic interactions; climate and niche; and management.

Main conclusions  Australian acacias are an excellent model group for examining interactions between evolutionary, ecological and socio‐economic drivers of species introductions. New insights have emerged on the biological, ecological and evolutionary correlates of naturalization and invasion, but human usage factors permeate all explanatory models. Understanding and managing introduced Australian acacias requires a fundamental and integrative appreciation of both intrinsic (e.g. species traits) and extrinsic (e.g. human usage and perceptions) aspects.
Fractionated plasma separation and adsorption: current practice and future options
Authors: Rifai Kinan
Published: August 2011

Fractionated plasma separation and adsorption (FPSA) is a method of albumin dialysis that is integrated into an extracorporeal liver support device (Prometheus®). This concept allows the effective removal of both protein‐bound and water‐soluble substances without the need for external albumin. Several studies comparing the in vivo extraction capacities of FPSA and molecular adsorbent recirculating system (MARS) concluded that detoxification by FPSA seems to be more effective than by MARS. Overall, FPSA therapy has been shown to be safe. Over the last few years, the anticoagulation protocol for FPSA therapy was optimised by using regional anticoagulation with citrate to avoid clotting of system components. Recently, the results of a large randomised‐controlled multicentre trial (HELIOS) have been presented. Survival after 1 and 3 months was evaluated in 145 patients with acute‐on‐chronic liver failure comparing FPSA therapy with standard medical treatment versus standard medical treatment alone. There was no statistically significant survival benefit for patients undergoing FPSA therapy. However, patients with hepatorenal syndrome type I or MELD score>30 showed a significant survival benefit under FPSA in a predefined subgroup analysis. Furthermore, there have been promising results with FPSA in the treatment of refractory cholestatic pruritus. Regarding acute liver failure, only few data are currently available.