bluuebunny/crossref_metadata_2025_split huggingface dataset:
A framework for evaluating management plans comprehensively
Authors: Trenkel Verena M , Rochet Marie‐Joëlle , Rice Jake C 
Published: October 2013

AbstractWe 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

AbstractTropical 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

AbstractBivalent 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).
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

Summary

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

AbstractThe 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

AbstractHuman 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

AbstractDesert 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

AbstractSoil 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

AbstractAimTo 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).LocationAtlanticOcean.MethodsThe 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.ResultsThe 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 conclusionsWe 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

AbstractAimFor 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.LocationGlobal.MethodsWe 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.ResultsAn 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 conclusionsThe 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

AbstractA 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

AimWe aimed to determine whether there was a Blue Zone, an area characterized by extreme longevity, in Menorca, Spain.MethodsWe explored official statistics of the Balearic Islands, Spain, and calculated life expectancy from 1991 to 2009, by sex and island, among other demographic estimators.ResultsThe 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.ConclusionsIt 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.