bluuebunny/crossref_metadata_2025 huggingface dataset:
Matrix metalloproteinase inhibitory properties of benzalkonium chloride stabilizes adhesive interfaces
Authors: Sabatini Camila , Patel Shaival K.
Published: October 2013

This study evaluated the effects of different concentrations of benzalkonium chloride (BAC) on the preservation of adhesive interfaces created with two etch‐and‐rinse adhesives and its inhibitory properties on dentin matrix metalloproteinase (MMP) activity. The following groups were tested with the adhesive systems Optibond Solo Plus and All‐Bond 3: Group 1, adhesive without inhibitor (control); Group 2, topical 2.0% chlorhexidine (2.0% CHX); Group 3, phosphoric acid with 1.0%wt BAC (BAC‐PA); Group 4, 0.25% BAC‐adhesive (0.25% BAC); Group 5, 0.5% BAC‐adhesive (0.5% BAC); Group 6, 1.0% BAC‐adhesive (1.0% BAC); and Group 7, 2.0% BAC‐adhesive (2.0% BAC). Composite cylinders were fabricated, and shear bond strength (SBS) was evaluated after 24 h, 6 months, and 18 months of storage. Extracts from concentrated demineralized human dentin powder were subjected to SDS‐PAGE and incubated in the presence of 0.25, 0.5, 1.0, and 2.0% BAC. Overall, stable bonds were maintained for 18 months. Improved bond strengths were seen for 0.5% BAC and 1.0% BAC when bonding with Optibond Solo Plus, and for 0.25% BAC and 0.5% BAC when bonding with All‐Bond 3. Zymographic analysis revealed complete inhibition of gelatinolytic activity with BAC. Benzalkonium chloride, at all concentrations, inhibited dentin proteolytic activity, which seems to have contributed to the improved bond stability after 18 months for specific combinations of BAC concentration and adhesive.
The role of stress as a trigger for epileptic seizures: A narrative review of evidence from human and animal studies
Authors: Novakova Barbora , Harris Peter R. , Ponnusamy Athi , Reuber Markus
Published: October 2013

Stress is one of the most frequently self‐identified seizure triggers in patients with epilepsy; however, most previous publications on stress and epilepsy have focused on the role of stress in the initial development of epilepsy. This narrative review explores the causal role of stress in triggering seizures in patients with existing epilepsy. Findings from human studies of psychological stress, as well as of physiologic stress responses in humans and animals, and evidence from nonpharmacologic interventions for epilepsy are considered. The evidence from human studies for stress as a trigger of epileptic seizures is inconclusive. Although retrospective self‐report studies show that stress is the most common patient‐perceived seizure precipitant, prospective studies have yielded mixed results and studies of life events suggest that stressful experiences only trigger seizures in certain individuals. There is limited evidence suggesting that autonomic arousal can precede seizures. Interventions designed to improve coping with stress reduce seizures in some individuals. Studies of physiologic stress using animal epilepsy models provide more convincing evidence. Exposure to exogenous and endogenous stress mediators has been found to increase epileptic activity in the brain and trigger overt seizures, especially after repeated exposure. In conclusion, stress is likely to exacerbate the susceptibility to epileptic seizures in a subgroup of individuals with epilepsy and may play a role in triggering “spontaneous” seizures. However, there is currently no strong evidence for a close link between stress and seizures in the majority of people with epilepsy, although animal research suggests that such links are likely. Further research is needed into the relationship between stress and seizures and into interventions designed to reduce perceived stress and improve quality of life with epilepsy.
Bilateral stereotactic radiofrequency amygdalohippocampectomy for a patient with bilateral temporal lobe epilepsy
Authors: Luo Huimin , Zhao Quanjun , Tian Zengmin , Wu Zhaohui , Wang Fuli , Lin Hong , Yin Feng , Zhao Hulin , Xiao Xia , Yu Xue , Wang Haiying , Zhao Hongxi , Cai Changlan
Published: October 2013

To search for a method for treatment of bilateral temporal lobe epilepsy (BTLE), we report one patient with BTLE experienced bilateral stereotactic radiofrequency amygdalohippocampectomy (SAHE). Neuropsychological examinations were performed before and 5 days, and 6, 18, and 48 months after operation. No seizure occurred in the follow‐up time, and no long‐term memory and intelligence deficits were found except for a transient decline of the scores immediately after operation. Because severe damage of memory could be caused by bilateral resection surgery, bilateral SAHE should be considered as a possible approach for the treatment of BTLE. However, further studies with accumulation of cases are needed, especially in the detailed assessment of neuropsychological function.
Epilepsy in ring 14 syndrome: A clinical and EEG study of 22 patients
Authors: Giovannini Simona , Marangio Lucia , Fusco Carlo , Scarano Angela , Frattini Daniele , Della Giustina Elvio , Zollino Marcella , Neri Giovanni , Gobbi Giuseppe
Published: October 2013

Purpose

To characterize epileptic phenotype, electroencephalography (EEG) features, and epileptic evolution in patients with ring 14 r(14) syndrome.

Methods

Twenty‐two patients with ring chromosome 14 were enrolled in the study. We examined age at onset, seizure semiology and frequency at onset and at follow‐up, drug responsiveness/resistance, and interictal/ictal EEG data. The degree of severity of the epileptic phenotype negatively influences child cognitive development.

Key Findings

The incidence of epilepsy in patients with r(14) syndrome is virtually 100%, characterized by early onset, polymorphic seizures, and drug‐resistant seizures. In addition, we ascertained focal secondarily generalized epilepsy, seizure cluster tendency, frequent status epilepticus, and a rather typical epilepsy evolution. EEG abnormalities consisted of slow background activity with pseudoperiodic bursts of generalized slow waves in the early stage, focal frontotemporal or temporoposterior slow waves with multifocal spikes interposed, and unusual rhythmic fast recruiting posterior spikes followed by secondary generalization. The degree of severity of the epileptic phenotype negatively influences child cognitive development.

Significance

This study provides a more precise definition of seizure types, natural history, and drug responsiveness of r(14) syndrome, a highly epileptogenic chromosomal condition.
Going beyond Research on Goal Setting: A Proposed Role for Organizational Psychological Capital of Family Firms
Authors: Memili Esra , Welsh Dianne H. B. , Luthans Fred
Published: October 2013

Kotlar and De Massis found that membership assortment and the number of organizational members, as well as the imminence of succession, influence goal diversity in family firms. They also showed that goal diversity can be managed and family–centered goals can be stabilized through professional and familial social interactions, driving the formation of collective commitment to family–centered goals (CCFG). Using this research as a point of departure, we propose that CCFG may impact family firm economic and noneconomic performance. Furthermore, we introduce to the family firm literature the organizational psychological capital (OPC), consisting of hope, efficacy, resilience, and optimism. We also suggest that OPC may be more prevalent in family firms than in nonfamily firms. Moreover, OPC of family firms may play an important role in the link between CCFG and economic as well as noneconomic performance.
Exit Strategies in Family Firms: How Socioemotional Wealth Drives the Threshold of Performance
Authors: DeTienne Dawn R. , Chirico Francesco
Published: October 2013

Although research has shown the ability to exit from both successful and unsuccessful ventures is important to founders, families, firms, industries, and overall economic health, exiting from a family firm can be especially challenging. In this paper, we examine exit strategies in the context of the family firm and the family firm portfolio. Drawing upon threshold theory and the socioemotional wealth perspective, we develop a model that provides guiding theoretical explanations for exit strategies. We address two questions: (1) why do family owners develop specific exit strategies, and (2) how do these strategies differ within family firms and family firm portfolios? In doing so, we contribute to family business, portfolio entrepreneurship, and exit literatures.
Socioemotional Wealth across the Family Firm Life Cycle: A Commentary on “Family Business Survival and the Role of Boards”
Authors: Le Breton–Miller Isabelle , Miller Danny
Published: October 2013

The differences among family firms can be as telling as their overall distinctiveness from other forms of enterprise. In order to advance and condition the arguments of Wilson, Wright, and Scholes, we employ a typology of family firm evolutionary development to illustrate how changes in patterns of family involvement in the business can influence several socioemotional wealth priorities and how these in turn can shape the board composition required to enhance firm survival. We conclude by arguing how public listing and environmental competitive circumstances can condition these relationships.
Insights from Family Science: The Case of Innovation
Authors: Penney Christopher R. , Combs James G.
Published: October 2013

By explaining processes through which familiness affects innovation, Carnes and Ireland take an important step toward explaining prior mixed findings. Their research also underscores the heterogeneity of families in that different family firms have different innovative outcomes. We adapt the circumplex model from family science research to help explain which families might innovate. Our larger purpose, however, is to offer a small example of the kind of theory building that we believe will be necessary for family businesses researchers to fully leverage insights from family science.
Variation in Note Composition ofChick‐a‐deeCalls is Associated with Signaler Flight in Carolina Chickadees,Poecile carolinensis
Authors: Freeberg Todd M. , Mahurin Ellen J.
Published: October 2013

Chick‐a‐deecalls are used in a wide range of social contexts inPoecile(chickadee) species. These calls comprise a number of distinct note types. Earlier naturalistic observational studies suggested that the ‘C’ note type was used frequently in calls of Carolina chickadees (P. carolinensis) in the context of flight. We conducted three field studies with Carolina chickadees to test in more experimentally manipulative ways whetherChick‐a‐deecalls with more ‘C’ notes were associated with flight. The three studies differed in how they elicited flight behavior from chickadees, as well as in the likely arousal levels experienced by the birds. First, we captured chickadees and released them, recording any calls they produced in flight or when later perched after escape. Second, we approached chickadees that were foraging near the ground in field settings and recorded any calls they produced when perched compared to when they were in flight. Third, from a distant blind, we recorded chickadees flying to and from feeding stations, in which the closest perching substrate/cover was at least 2 m away from the feeding station, thus requiring flight. In all three studies, calls contained more ‘C’ notes when birds were in flight compared to when they were perched. This work expands our understanding of variation in note composition ofchick‐a‐deecalls beyond the contexts of food and predator detection to the context of movement. Studies are now needed to test whether such variation inchick‐a‐deecalls brings about group cohesion.
Color Polymorphism in Spiny Spiders (Gasteracantha fornicata): Testing the Adaptive Significance of a Geographically Clinal Lure
Authors: Kemp Darrell J. , Holmes Claire , Congdon Bradley C. , Edwards Will
Published: October 2013

Many sit‐and‐wait predators use conspicuous displays of color to attract prey. These displays sometimes express discrete polymorphisms; however, the adaptive drivers of such variation are not well understood. Here, we explore a previously unknown color polymorphism in the orb‐web spider Gasteracantha fornicata. We discovered that in North Queensland, Australia, female spiders exhibit dorsal bands appearing (to the human observer) either white or yellow and characterized by sigmoidal spectral curves centered on approx. 447 and 496 nm, respectively. Based on sensory drive theory, we hypothesized that morphs may be alternatively favored by the switch in ambient viewing conditions engendered by sunny vs. cloudy skies. We addressed this hypothesis indirectly by studying morph frequencies across a approx. 200 km geographic gradient of solar exposure (a surrogate for cloudiness), and by investigating the phenotypic signature of catch success via a resource stress experiment and in wild spiders. Our data indicate substantial geographic variation in morph frequency, with white morphs dominating at more cloudy northern locations. Rather than a gradual cline, morph frequency inverted mid‐way along this range and was closely fit by a logistic relationship with latitude. Experimentally restricted access to larger prey caused spiders to lose more mass than size and to exhibit less bright dorsal markings. Wild‐sampled spiders from two localities of divergent morph frequency indicated no differences in residual mass, but intriguingly, the white morph was larger and heavier (than the yellow morph) where it was relatively rare. Our data hint at negative frequency dependence, but remain broadly consistent with a sensory drive explanation based on cloudiness, and we suggest these as worthy avenues for closer investigation.
Cobreeding in the Burying Beetle, Nicrophorus vespilloides: Tolerance Rather Than Cooperation
Authors: Komdeur Jan , Schrama Maarten J. J. , Meijer Kim , Moore Allen J. , Beukeboom Leo W.
Published: October 2013

Under intra‐ and interspecific competition, cooperative behaviour can provide direct fitness benefits if individuals work together to expel intruders. In the burying beetle Nicrophorus vespilloides, a relatively small species, multiple unrelated pairs can breed together, and individuals are weak competitors in interactions when competing with larger individuals of the same species and with larger species of the same genus. In field and laboratory studies, we found that two pairs together attracted significantly fewer congeneric and non‐congeneric competitors compared with single pairs. No other benefits were found. Communal breeding had large negative effects on fitness, as there were fewer offspring per pair and a higher chance of injuries. The higher chance of injuries reflected pairs fighting among themselves and not against competitors. These costs are much greater than the small benefit of fewer intruders. Why should a N. vespilloides breeding pair eventually allow another pair to join? A potential partial explanation is that these are not cooperative pairs in the traditional sense, but rather pairs have a higher tolerance for each other. From the resident's perspective, joining pairs are not expelled because the chance of injury makes the cost of fighting high. Joining others may have unusually low costs in this species because reproductive opportunities are rare, dependent on a resource that is unpredictable in time and space, and residents should be inclined to tolerating new pairs because of the cost of fighting. Thus, for N. vespilloides, communal breeding appears to be ‘making the best of a bad job’, providing some reproduction rather than none.
Evolutionary and plastic responses of freshwater invertebrates to climate change: realized patterns and future potential
Authors: Stoks Robby , Geerts Aurora N. , De Meester Luc
Published: October 2013

We integrated the evidence for evolutionary and plastic trait changes in situ in response to climate change in freshwater invertebrates (aquatic insects and zooplankton). The synthesis on the trait changes in response to the expected reductions in hydroperiod and increases in salinity indicated little evidence for adaptive, plastic, and genetic trait changes and for local adaptation. With respect to responses to temperature, there are many studies on temporal trait changes in phenology and body size in the wild that are believed to be driven by temperature increases, but there is a general lack of rigorous demonstration whether these trait changes are genetically based, adaptive, and causally driven by climate change. Current proof for genetic trait changes under climate change in freshwater invertebrates stems from a limited set of common garden experiments replicated in time. Experimental thermal evolution experiments and common garden warming experiments associated with space‐for‐time substitutions along latitudinal gradients indicate that besides genetic changes, also phenotypic plasticity and evolution of plasticity are likely to contribute to the observed phenotypic changes under climate change in aquatic invertebrates. Apart from plastic and genetic thermal adjustments, also genetic photoperiod adjustments are widespread and may even dominate the observed phenological shifts.
Combining genetic and demographic information to prioritize conservation efforts for anadromous alewife and blueback herring
Authors: Palkovacs Eric P. , Hasselman Daniel J. , Argo Emily E. , Gephard Stephen R. , Limburg Karin E. , Post David M. , Schultz Thomas F. , Willis Theodore V.
Published: October 2013

A major challenge in conservation biology is the need to broadly prioritize conservation efforts when demographic data are limited. One method to address this challenge is to use population genetic data to define groups of populations linked by migration and then use demographic information from monitored populations to draw inferences about the status of unmonitored populations within those groups. We applied this method to anadromous alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis), species for which long‐term demographic data are limited. Recent decades have seen dramatic declines in these species, which are an important ecological component of coastal ecosystems and once represented an important fishery resource. Results show that most populations comprise genetically distinguishable units, which are nested geographically within genetically distinct clusters or stocks. We identified three distinct stocks in alewife and four stocks in blueback herring. Analysis of available time series data for spawning adult abundance and body size indicate declines across the US ranges of both species, with the most severe declines having occurred for populations belonging to the Southern New England and the Mid‐Atlantic Stocks. While all alewife and blueback herring populations deserve conservation attention, those belonging to these genetic stocks warrant the highest conservation prioritization.
Carpal hyperextension in a Percheron mare caused by a palmar carpal ligament tear
Authors: Barba M. , McMaster M. , Albanese V. , Cole R. , Caldwell F. , Schumacher J.
Published: October 2013

A Percheron mare was presented for acute, severe lameness and marked swelling of the right forelimb after being cast. The mare was initially diagnosed with cellulitis of the forelimb but as her condition improved and the affected limb was able to bear more weight it became apparent that the limb was hyperextended at the level of the carpus. Widening of the palmar aspect of the middle carpal joint was observed radiographically. During ultrasonographic examination, excessive fluid in the carpal sheath and perithecal swelling were noted and tearing of the palmar carpal ligament was suspected. A dynamic brace was fabricated to prevent hyperextension of the carpus. After discontinuation of systemic antibiotics, the mare became febrile and forelimb lameness worsened. Cytology of fluid from the middle carpal joint confirmed joint sepsis and the mare was anaesthetised for arthroscopic examination. A tear in the palmar carpal ligament, characterised by focal fibre disruption and fibrillation, was identified during arthroscopic and tenoscopic examination. Communication between the carpal flexor tendon sheath and middle carpal joint was identified during these procedures. Both the middle carpal joint and carpal flexor tendon sheath were lavaged with physiological saline solution. Post operatively, swelling and lameness slowly resolved. Four months after discharge, the mare was sufficiently sound to be maintained at pasture. Viewed from its lateral aspect, the limb no longer appeared to be hyperextended from the carpus.
A preventive multimodal analgesic strategy for bilateral rostral mandibulectomy in a horse
Authors: Minghella E. , Auckburally A.
Published: October 2013

This case report describes the use of a wound soaker catheter as part of a preventive multimodal analgesic plan in a mare undergoing a bilateral rostral mandibulectomy. The administration of local anaesthetic into the surgical wound using a wound soaker catheter, together with systemic nonsteroidal anti‐inflammatory drugs (NSAIDs) and opioid therapy, controlled post operative pain satisfactorily.
Antimicrobial peptides and pro‐inflammatory cytokines are differentially regulated across epidermal layers following bacterial stimuli
Authors: Percoco Giuseppe , Merle Chloé , Jaouen Thomas , Ramdani Yasmina , Bénard Magalie , Hillion Mélanie , Mijouin Lily , Lati Elian , Feuilloley Marc , Lefeuvre Luc , Driouich Azeddine , Follet‐Gueye Marie‐Laure
Published: October 2013

The skin is a natural barrier between the body and the environment and is colonised by a large number of microorganisms. Here, we report a complete analysis of the response of human skin explants to microbial stimuli. Using this ex vivo model, we analysed at both the gene and protein level the response of epidermal cells to Staphylococcus epidermidis (S. epidermidis) and Pseudomonas fluorescens (P. fluorescens), which are present in the cutaneous microbiota. We showed that both bacterial species affect the structure of skin explants without penetrating the living epidermis. We showed by real‐time quantitative polymerase chain reaction (qPCR) that S. epidermidis and P. fluorescens increased the levels of transcripts that encode antimicrobial peptides (AMPs), including human β defensin (hBD)2 and hBD3, and the pro‐inflammatory cytokines interleukin (IL)‐1α and (IL)‐1‐β, as well as IL‐6. In addition, we analysed the effects of bacterial stimuli on the expression profiles of genes related to innate immunity and the inflammatory response across the epidermal layers, using laser capture microdissection (LCM) coupled to qPCR. We showed that AMP transcripts were principally upregulated in suprabasal keratinocytes. Conversely, the expression of pro‐inflammatory cytokines was upregulated in the lower epidermis. These findings were confirmed by protein localisation using specific antibodies coupled to optical or electron microscopy. This work underscores the potential value of further studies that use LCM on human skin explants model to study the roles and effects of the epidermal microbiota on human skin physiology.
A framework for evaluating management plans comprehensively
Authors: Trenkel Verena M , Rochet Marie‐Joëlle , Rice Jake C
Published: October 2013

We present a framework for evaluating fisheries management plans comprehensively, both rebuilding plans and others. The framework includes a first rapid appraisal of the likelihood that the plan will result in management meeting its objectives, and guides subsequent quantitative analyses of potential weaknesses in the proposed plan. The framework includes four steps: (i) evaluating if a set of management objectives, if achieved, would result in a sustainable fishery, (ii) using qualitative analysis of a bio‐economic model to evaluate whether the set of stock management tactics might be capable of achieving the specified fisheries objectives, (iii) using empirical criteria derived from the literature to evaluate if other management measures in the plan related to the ecological, social or economic context of the fishery actually contribute to sustainability, and (iv) carrying out quantitative simulations to compare alternative implementation options. Generally, several management measures have to be combined to increase stock size without sacrificing the economic benefits to the fishers remaining in the fishery. We demonstrate application of the framework for evaluating the stock rebuilding plan for plaice (Pleuronectes platessa) and sole (Solea solea) in the North Sea and, the management measures currently in place for the roundnose grenadier (Coryphaenoides rupestris) stock exploited to the west of the British Isles.
The sea cucumber fishery in Australia's Great Barrier Reef Marine Park follows global patterns of serial exploitation
Authors: Eriksson Hampus , Byrne Maria
Published: October 2013

Tropical sea cucumber fisheries follow a predictable pattern of serial depletion. Overfishing is exacerbated in developing countries where management systems lack capacity to control large numbers of fishers influenced by poverty. In contrast, the tropical sea cucumber fishery in Australia's World Heritage listed Great Barrier Reef Marine Park (GBRMP) is operating in a developed high‐income country with relatively few licensed fishers to manage. The development of this fishery is reviewed here in a meta‐analysis of catches from 1991 to 2011. The fishery expanded to replace high‐value teatfish species (Holothuria whitmaei and H. fuscogilva), fished heavily in initial stages of the fishery, with newly commercialized medium‐value species such as burying blackfish (Actinopyga spinea) and curryfish (Stichopus herrmanni). These two species now constitute 80% of total catch. The annual average catch of burying blackfish was 208 tonnes years 2004–11 and curryfish catches increased rapidly at an average annual pace of 200% from 2007–11. This serial harvest pattern occurred in the absence of baseline studies and without independent resource assessments, information required to inform relevant harvest predictions and to determine fishery impacts. This situation does not support ecologically relevant and adaptive decision‐making in management and the unfolding catch patterns in the GBRMP follow those in low‐income developing countries. The missing knowledge and lack of data serve as arguments to support precautionary reductions in harvests and extending fallow periods in fishing zones.
Avidity and positive allosteric modulation/cooperativity act hand in hand to increase the residence time of bivalent receptor ligands
Authors: Vauquelin Georges , Bricca Giampiero , Van Liefde Isabelle
Published: October 2013

Bivalent ligands bear two target‐binding pharmacophores. Their simultaneous binding increases their affinity (avidity) and residence time. They become ‘bitopic’ when the binding sites at the target permit the pharmacophores the exert allosteric modulation of each other's affinity and/or activity. Present simulations reveal that positive cooperativity exacerbates these phenomena, whereas negative cooperativity curtails them, irrespective of whether the association or dissociation rates of the individual pharmacophores are affected. Positive cooperativity delays the attainment of equilibrium binding, yielding ‘hemi‐equilibrium’ conditions and only apparent affinity constants under usual experimental conditions. Monovalent ligands that bind to one of the target sites decrease the bitopic ligand's residence time concentration‐wise; their potency depends on their association rate and thereon acting cooperativity rather than on affinity. This stems from the repetitive, very fast reformation of fully bound bitopic ligand‐target complexes by rebinding of freshly dissociated pharmacophores. These studies deal with kinetic binding properties (of increasing interest in pharmacology) of bitopic ligands (a promising avenue in medicinal chemistry).
Human tissue in systems medicine
Authors: Caie Peter D. , Schuur Klaas , Oniscu Anca , Mullen Peter , Reynolds Paul A. , Harrison David J.
Published: October 2013

Histopathology, the examination of an architecturally artefactual, two‐dimensional and static image remains a potent tool allowing diagnosis and empirical expectation of prognosis. Considerable optimism exists that the advent of molecular genetic testing and other biomarker strategies will improve or even replace this ancient technology. A number of biomarkers already add considerable value for prediction of whether a treatment will work. In this short review we argue that a systems medicine approach to pathology will not seek to replace traditional pathology, but rather augment it. Systems approaches need to incorporate quantitative morphological, protein, mRNA and DNA data. A significant challenge for clinical implementation of systems pathology is how to optimize information available from tissue, which is frequently sub‐optimal in quality and amount, and yet generate useful predictive models that work. The transition of histopathology to systems pathophysiology and the use of multiscale data sets usher in a new era in diagnosis, prognosis and prediction based on the analysis of human tissue.
How not to do kinetics: examples involving GTPases and guanine nucleotide exchange factors
Authors: Goody Roger S.
Published: October 2013

Guanine nucleotide exchange factors (GEFs) are crucial regulators of the action of GTPases in signal transduction and cellular regulation. Although their basic mechanism of action has been apparent for almost 20 years, there are still misconceptions concerning their properties, and these are confounded by superficial or incorrect interpretation of experimental results in individual cases. Here, an example is described in which an incorrect mechanism was derived because of an inadequate analysis of kinetic results. In a second example, a case is discussed where certain GTP analogs were erroneously described as being able to function as low molecular mass GEFs. In both cases, a lack of distinction between rates, rate constants, and apparent rate constants, together with a disregard of relative signal amplitudes, led to the misinterpretations. In a final example, it is shown how the lack of an appropriate kinetic investigation led to the false conclusion that a secreted protein from Legionella pneumophila can act not only as a GEF towards eukaryotic Rab1 but also as a factor that is able to actively dissociate the stable complex between Rab1 and GDP dissociation inhibitor.
Escapement success of silver eels from a German river system is low compared to management‐based estimates
Authors: Marohn Lasse , Prigge Enno , Hanel Reinhold
Published: October 2013

The European eel (Anguilla anguilla) stock experienced a sharp decline during the last decades and is suffering from massive anthropogenic impacts on inland waters. To evaluate the benefit of management measures and to better understand the contribution of single drainage systems to spawner production, knowledge of the respective silver eel escapement is required. Furthermore, a better understanding of environmental conditions that potentially trigger the onset of spawning migration is needed to reduce anthropogenic mortalities during riverine eel migration. Investigations are also necessary to clarify whether fish protecting devices and bypasses at barriers are functional and truly increase eel survival and escapement rates.

In this study, total female silver eel escapement from a northern German drainage system (Schwentine River) was assessed over a period of three consecutive years, and downstream migration patterns were compared to potential environmental triggers. Furthermore, the benefit of two fish bypasses (surface and deep) and a trash rack at the hydropower station for the survival of migrating eels was examined, and the spawner quality of escaping silver eels was determined by analysing lipid content and infection intensities with the swimbladder parasite Anguillicoloides crassus.

The results indicate that silver eel escapement from the Schwentine drainage system is far below the estimated values underlying the respective eel management plan, highlighting the necessity of direct migration assessments to validate indirect estimations that include multiple assumptions and uncertainties. Major downstream migration events took place during short time periods in autumn and appear to be influenced by river discharge and water temperatures, suggesting that a precise prediction of escapement events is possible. Regarding spawner quality, fat reserves appear sufficient for escaping silver eels to migrate and spawn. However, high A. crassus prevalence and infection intensities are assumed to further reduce the number of potential spawners. Another matter of concern is the high trash rack mortality at the hydropower station that illustrates the need of fish protecting devices that fulfil eel‐specific requirements.
The use of mouse models to unravel genetic architecture of physical activity: a review
Authors: Kostrzewa E. , Kas M. J.
Published: October 2013

The discovery of genetic variants that underlie a complex phenotype is challenging. One possible approach to facilitate this endeavor is to identify quantitative trait loci (QTL) that contribute to the phenotype and consequently unravel the candidate genes within these loci. Each proposed candidate locus contains multiple genes and, therefore, further analysis is required to choose plausible candidate genes. One of such methods is to use comparative genomics in order to narrow down the QTL to a region containing only a few genes. We illustrate this strategy by applying it to genetic findings regarding physical activity (PA) in mice and human. Here, we show that PA is a complex phenotype with a strong biological basis and complex genetic architecture. Furthermore, we provide considerations for the translatability of this phenotype between species. Finally, we review studies which point to candidate genetic regions for PA in humans (genetic association and linkage studies) or use mouse models of PA (QTL studies) and we identify candidate genetic regions that overlap between species. On the basis of a large variety of studies in mice and human, statistical analysis reveals that the number of overlapping regions is not higher than expected on a chance level. We conclude that the discovery of new candidate genes for complex phenotypes, such as PA levels, is hampered by various factors, including genetic background differences, phenotype definition and a wide variety of methodological differences between studies.
Multi‐nutrient vs. nitrogen‐only effects on carbon sequestration in grassland soils
Authors: Fornara Dario A. , Banin Lindsay , Crawley Michael J.
Published: October 2013

Human activities have greatly increased the availability of biologically active forms of nutrients [e.g., nitrogen (N), phosphorous (P), potassium (K), magnesium (Mg)] in many soil ecosystems worldwide. Multi‐nutrient fertilization strongly increases plant productivity but may also alter the storage of carbon (C) in soil, which represents the largest terrestrial pool of organic C. Despite this issue is important from a global change perspective, key questions remain on how the single addition of N or the combination of N with other nutrients might affect C sequestration in human‐managed soils. Here, we use a 19‐year old nutrient addition experiment on a permanent grassland to test for nutrient‐induced effects on soil C sequestration. We show that combined NPKMg additions to permanent grassland have ‘constrained’ soil C sequestration to levels similar to unfertilized plots whereas the single addition of N significantly enhanced soil C stocks (N‐only fertilized soils store, on average, 11 t C ha−1 more than unfertilized soils). These results were consistent across grazing and liming treatments suggesting that whilst multi‐nutrient additions increase plant productivity, soil C sequestration is increased by N‐only additions. The positive N‐only effect on soil C content was not related to changes in plant species diversity or to the functional composition of the plant community. N‐only fertilized grasslands show, however, increases in total root mass and the accumulation of organic matter detritus in topsoils. Finally, soils receiving any N addition (N only or N in combination with other nutrients) were associated with high N losses. Overall, our results demonstrate that nutrient fertilization remains an important global change driver of ecosystem functioning, which can strongly affect the long‐term sustainability of grassland soil ecosystems (e.g., soils ability to deliver multiple ecosystem services).
Long‐term response of a Mojave Desert winter annual plant community to a whole‐ecosystem atmospheric CO2 manipulation (FACE)
Authors: Smith Stanley D. , Charlet Therese N. , Zitzer Stephen F. , Abella Scott R. , Vanier Cheryl H. , Huxman Travis E.
Published: October 2013

Desert annuals are a critically important component of desert communities and may be particularly responsive to increasing atmospheric (CO2) because of their high potential growth rates and flexible phenology. During the 10‐year life of the Nevada Desert FACE (free‐air CO2 enrichment) Facility, we evaluated the productivity, reproductive allocation, and community structure of annuals in response to long‐term elevated (CO2) exposure. The dominant forb and grass species exhibited accelerated phenology, increased size, and higher reproduction at elevated (CO2) in a wet El Niño year near the beginning of the experiment. However, a multiyear dry cycle resulted in no increases in productivity or reproductive allocation for the remainder of the experiment. At the community level, early indications of increased dominance of the invasive Bromus rubens at elevated (CO2) gave way to an absence of Bromus in the community during a drought cycle, with a resurgence late in the experiment in response to higher rainfall and a corresponding high density of Bromus in a final soil seed bank analysis, particularly at elevated (CO2). This long‐term experiment resulted in two primary conclusions: (i) elevated (CO2) does not increase productivity of annuals in most years; and (ii) relative stimulation of invasive grasses will likely depend on future precipitation, with a wetter climate favoring invasive grasses but currently predicted greater aridity favoring native dicots.
Soil microbial and nutrient responses to 7 years of seasonally altered precipitation in a Chihuahuan Desert grassland
Authors: Bell Colin W. , Tissue David T. , Loik Michael E. , Wallenstein Matthew D. , Acosta ‐ Martinez Veronica , Erickson Richard A. , Zak John C.
Published: October 2013

Soil microbial communities in Chihuahuan Desert grasslands generally experience highly variable spatiotemporal rainfall patterns. Changes in precipitation regimes can affect belowground ecosystem processes such as decomposition and nutrient cycling by altering soil microbial community structure and function. The objective of this study was to determine if increased seasonal precipitation frequency and magnitude over a 7‐year period would generate a persistent shift in microbial community characteristics and soil nutrient availability. We supplemented natural rainfall with large events (one/winter and three/summer) to simulate increased precipitation based on climate model predictions for this region. We observed a 2‐year delay in microbial responses to supplemental precipitation treatments. In years 3–5, higher microbial biomass, arbuscular mycorrhizae abundance, and soil enzyme C and P acquisition activities were observed in the supplemental water plots even during extended drought periods. In years 5–7, available soil P was consistently lower in the watered plots compared to control plots. Shifts in soil P corresponded to higher fungal abundances, microbial C utilization activity, and soilpH. This study demonstrated that 25% shifts in seasonal rainfall can significantly influence soil microbial and nutrient properties, which in turn may have long‐term effects on nutrient cycling and plant P uptake in this desert grassland.
Biogeographic, historical and environmental influences on the taxonomic and functional structure ofAtlantic reef fish assemblages
Authors: Bender Mariana G. , Pie Marcio R. , Rezende Enrico L. , Mouillot David , Floeter Sergio R.
Published: October 2013

Aim

To disentangle how historic, biogeographic and environmental factors have shaped the composition of different reef fish assemblages, we analysed assemblage structure from a taxonomic (proportions of species from different families) and functional perspective (diet and body size).

Location

AtlanticOcean.

Methods

The distributions of 1629 fish species were compiled for 31 locations across theAtlanticOcean (39°66′N, 27°50′S). These locations provide a richness gradient ranging from 54 species inStPaul'sRocks to 474 inCuba. We used cluster analyses to assess how historical and biogeographic factors have shaped the taxonomic and functional structure (i.e. the distribution of species within families, diet and body size groups) of assemblages. We then employed a constrained analysis of principal coordinates (CAP) to test the relative influence of the distance from the biodiversity centre in theAtlantic, sea surface temperature, isolation, coral species richness and area, and coastal length on the observed patterns of assemblage structure.

Results

The taxonomic and functional structure of reef fish assemblages across theAtlantic exhibits a biogeographic fingerprint, with a marked discrimination between species‐rich biogenic reefs (concentrated primarily in theCaribbean and composed of small species feeding on invertebrates) and poorer peripheral regions dominated by larger species with more diverse diets. The firstCAPaxis explains 87% of body size distribution in assemblages, showing that the effects of sea surface temperature and coral richness and those of isolation are antagonistic and can be embedded into a single dimension. Environmental factors, such as temperature and habitat complexity, explain the disproportionate number of small species in theCaribbean, whereas in the remaining regions the predominance of large‐bodied fish increases with isolation due to high dispersal ability.

Main conclusions

We found that historical events, which have shaped the biogeography of reef fishes, and environmental characteristics (coral reefs versus periphery) have both played a role in structuring the taxonomic and functional components of Atlantic fish assemblages.
Mechanisms driving an unusual latitudinal diversity gradient for grasses
Authors: Visser Vernon , Clayton W. Derek , Simpson David A. , Freckleton Robert P. , Osborne Colin P.
Published: October 2013

Aim

For most higher‐order taxa, species diversity peaks sharply in the moist tropics and declines rapidly at higher latitudes. However, the mechanisms driving this latitudinal gradient are numerous, remain uncertain and are even undocumented in some important major clades such as the grasses. Grasses are a cosmopolitan, important plant family with more than 11,000 species world‐wide. Our aims were: to investigate the latitudinal distributions of species richness for different grass lineages, and the grass family as a whole; and to test hypotheses proposed in general for the latitudinal diversity gradient or specifically as determinants of grass species richness patterns at the global scale.

Location

Global.

Methods

We used the most comprehensive global database of grass distributions currently available to calculate species richness for 340 political regions of the world. Using generalized additive models we used these data to model the latitudinal gradients of species richness for different grass lineages and for the grass family as a whole. We constructed multiple regression models to include climatic, productivity, topographic, habitat and geographic variables.

Results

An unusual, shallow latitudinal diversity gradient arises because different grass lineages exhibit contrasting latitudinal patterns. This reflects differential specialization of grass lineages to arid and cool environments, the legacy of historical effects, most notably the Gondwanan origin of the grasses, and a strong association between grasses and topographically heterogeneous, mountainous regions.

Main conclusions

The grasses are one of the relatively few higher‐order lineages that exhibits an atypical latitudinal gradient; this has arisen because of climatic specialization of particular grass lineages to cold and arid environments. Key additional roles have been inferred for historical biogeography and topographical heterogeneity in determining global patterns of grass species richness. These mechanisms have generally been under‐appreciated and are probably important for many other lineages.
Forage yield and competition indices of faba bean intercropped with oat
Authors: Dhima K. V. , Vasilakoglou I. B. , Keco R. Xh. , Dima A. K. , Paschalidis K. Α. , Gatsis T. D.
Published: October 2013

A 2‐year field study was conducted using one oat (Avena sativa L.) cultivar (‘Cassandra’) and two faba bean (Vicia faba L.) cultivars (‘Polykarpe’ and ‘Tanagra’) as sole crops and six faba bean–oat intercrops seeded at three seeding ratios (75–25, 50–50 and 25–75%). Land‐equivalent ratio (LER) and competition ratio (CR) indices were also assessed. Two‐year mean annual dry‐matter (DM) yield of all intercrops averaged 17·2 t ha−1 and this was greater than that of both faba bean sole crops, which averaged 12·7 t ha−1. However, intercrop DM was significantly lower than that of oat sole crop, which averaged 24·9 t ha−1. The most productive intercrop was that of faba bean–oat at 25–75 seeding ratio. The intercropped oat had higher LER than either of the intercropped faba bean cultivars, indicating an advantage for oat intercropped with faba bean. The results of this study indicated that faba bean–oat intercrops provided higher total DM and protein yields than those of faba bean sole crop, but lower or similar yields to oat as a sole crop. Results are discussed in the context of providing forages in Mediterranean environments that are of balanced nutritional value. Thus, intercropping of either of the tested faba bean cultivars with oat (cv. Cassandra) at a 25–75 seeding ratio could be used as an alternative to faba bean sole crop or faba bean–cereals intercrops for satisfactory forage and protein yield.
Description of extreme longevity in the Balearic Islands: Exploring a potential Blue Zone in Menorca, Spain
Authors: Soriano Joan B , Fernández Vázquez Sara , Carretero Silvia , Puga González María Dolores , Soriano Cecilia , Romaguera Dora , Alonso‐Fernández Alberto , Busquets Xavier , Balcells Susana , Grinberg Daniel , Poulain Michel
Published: October 2013

Aim

We aimed to determine whether there was a Blue Zone, an area characterized by extreme longevity, in Menorca, Spain.

Methods

We explored official statistics of the Balearic Islands, Spain, and calculated life expectancy from 1991 to 2009, by sex and island, among other demographic estimators.

Results

The life expectancy at birth in Menorca reached a peak in 2007 with 82.3 years, but since 2001 in females and 2007 in males, it plateaued and then descended. The percentage of centenarians in Es Migjorn Gran was 0.17% in 2001, only because of the 0.33% male contribution, and it returned to within the average Balearic rates. There is no record of any other surviving centenarian after 2006 in Es Migjorn Gran. Results obtained with other demographic indices are confirmatory.

Conclusions

It appears there was no extreme longevity or Blue Zone in Es Migjorn Gran and the surrounding villages in Menorca. Geriatr Gerontol Int 2014; 14: 620–627.