696 research outputs found
Fishery essentiality: A short-term decision-making method based on economic viability as a tool to understand and manage data-limited small-scale fisheries
Small-scale fisheries (SSFs), usually overlooked and marginalized in policy processes, play an important role in contributing to food security, nutrition, livelihoods, and local and national economies. As conventional fisheries assessment is not valid for SSFs, this study puts forward several mathematical indices to numerically qualify the state of certain SSFs. We have developed a new concept of ‘essentiality’, which measures the relative importance of certain species from an economic perspective. In the framework of fishery essentiality, SSFs boats are conceptually replaced by Artisanal Fishing Units. The time dedicated to the capture of a species, the number of units that fish it, and the economic yield obtained from the sale of the catch: Frequency, Fleet Recruiting and Income, define essentiality. We have set out an overall index of essential capacity for the whole fishery. Estimating the essentiality of a fishery allows us to comparatively characterize different fishing communities, and the data-limited SSF manager has the option of introducing management measures to change the behaviour of the fishery and move towards a situation of greater essentiality, and therefore, of greater economic viability. This in turn leads to a reduction in the pressure that is focused on a limited number of specific fishing resources. The essentiality of a fishery is a plausible alternative method of assessment and management of a fishery to the traditional evaluation methods used for industrial fisheries.Versión del editor1,58
Discovery of a massive supercluster system at
Superclusters are the largest relatively isolated systems in the cosmic web.
Using the SDSS BOSS survey we search for the largest superclusters in the
redshift range .
We generate a luminosity-density field smoothed over
to detect the large-scale over-density regions. Each individual over-density
region is defined as single supercluster in the survey. We define the
superclusters in the way that they are comparable with the superclusters found
in the SDSS main survey.
We found a system we call the BOSS Great Wall (BGW), which consists of two
walls with diameters 186 and 173 Mpc, and two other major superclusters
with diameters of 64 and 91 Mpc. As a whole, this system consists of
830 galaxies with the mean redshift 0.47. We estimate the total mass to be
approximately . The morphology of the
superclusters in the BGW system is similar to the morphology of the
superclusters in the Sloan Great Wall region.
The BGW is one of the most extended and massive system of superclusters yet
found in the Universe.Comment: 4 pages, accepted as a letter in A&
How much dark matter is there inside early-type galaxies?
We study the luminous mass as a function of the dynamical mass inside the
effective radius (r_e) of early-type galaxies (ETGs) to search for differences
between these masses. We assume Newtonian dynamics and that any difference
between these masses is due to the presence of dark matter. We use several
samples of ETGs -ranging from 19 000 to 98 000 objects- from the ninth data
release of the Sloan Digital Sky Survey. We perform Monte Carlo (MC)
simulations of galaxy samples and compare them with real samples. The main
results are: i) MC simulations show that the distribution of the dynamical vs.
luminous mass depends on the mass range where the ETGs are distributed
(geometric effect). This dependence is caused by selection effects and
intrinsic properties of the ETGs. ii) The amount of dark matter inside r_e is
approximately 7% +- 22%. iii) This amount of dark matter is lower than the
minimum estimate (10%) found in the literature and four times lower than the
average (30%) of literature estimates. However, if we consider the associated
error, our estimate is of the order of the literature average.Comment: 24 pages, 12 figures. MNRAS accepte
A semi-analytical perspective on massive galaxies at
The most massive and luminous galaxies in the Universe serve as powerful
probes to study the formation of structure, the assembly of mass, and
cosmology. However, their detailed formation and evolution is still barely
understood. Here we extract a sample of massive mock galaxies from the
semi-analytical model of galaxy formation (SAM) GALACTICUS from the
MultiDark-Galaxies, by replicating the CMASS photometric selection from the
SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). The comparison of the
GALACTICUS CMASS-mock with BOSS-CMASS data allows us to explore different
aspects of the massive galaxy population at , including the
galaxy-halo connection and the galaxy clustering. We find good agreement
between our modelled galaxies and observations regarding the galaxy-halo
connection, but our CMASS-mock over-estimates the clustering amplitude of the
2-point correlation function, due to a smaller number density compared to BOSS,
a lack of blue objects, and a small intrinsic scatter in stellar mass at fixed
halo mass of dex. To alleviate this problem, we construct an alternative
mock catalogue mimicking the CMASS colour-magnitude distribution by randomly
down-sampling the SAM catalogue. This CMASS-mock reproduces the clustering of
CMASS galaxies within 1 and shows some environmental dependency of star
formation properties that could be connected to the quenching of star formation
and the assembly bias.Comment: 15 pages, 10 figures, 2 tables, submitted to MNRA
Variable Stars in Local Group Galaxies. IV. RR Lyrae stars in the central regions of the low-density galaxy Crater II
We present a search and analysis of variable stars in the recently discovered
Crater~II dwarf galaxy. Based on , , data collected with the Isaac
Newton Telescope (FoV0.44 square degrees) we detected 37 variable stars,
of which 34 are bone-fide RR Lyrae stars of Crater~II (28 RRab, 4 RRc, 2 RRd).
We applied the metal-independent (, ) Period--Wesenheit relation and
derived a true distance modulus ( = 20.300.08 mag (=0.16
mag). Individual metallicities for RR Lyrae stars were derived by inversion of
the predicted -band Period-Luminosity relation. We find a mean metallicity
of [Fe/H]=-1.64 and a standard deviation of =0.21 dex,
compatible with either negligible or vanishing intrinsic metallicity
dispersion. The analysis of the Colour-Magnitude Diagram reveals a stark
paucity of blue horizontal branch stars, at odds with other Galactic dwarfs,
and globular clusters with similar metal abundances.Comment: 14 pages, 8 figures, accepted for publications on MNRAS. Time series
photometry is available in the manuscript source ta
Training primary care physicians to offer their patients faecal occult blood testing and colonoscopy for colorectal cancer screening on an equal basis: a pilot intervention with before-after and parallel group surveys.
Primary care physicians (PCPs) should prescribe faecal immunochemical testing (FIT) or colonoscopy for colorectal cancer screening based on their patient's values and preferences. However, there are wide variations between PCPs in the screening method prescribed. The objective was to assess the impact of an educational intervention on PCPs' intent to offer FIT or colonoscopy on an equal basis.
Survey before and after training seminars, with a parallel comparison through a mailed survey to PCPs not attending the training seminars.
All PCPs in the canton of Vaud, Switzerland.
Of 592 eligible PCPs, 133 (22%) attended a seminar and 106 (80%) filled both surveys. 109 (24%) PCPs who did not attend the seminars returned the mailed survey.
A 2 h-long interactive seminar targeting PCP knowledge, skills and attitudes regarding offering a choice of colorectal cancer (CRC) screening options.
The primary outcome was PCP intention of having their patients screened with FIT and colonoscopy in equal proportions (between 40% and 60% each). Secondary outcomes were the perceived role of PCPs in screening decisions (from paternalistic to informed decision-making) and correct answer to a clinical vignette.
Before the seminars, 8% of PCPs reported that they had equal proportions of their patients screened for CRC by FIT and colonoscopy; after the seminar, 33% foresaw having their patients screened in equal proportions (p<0.001). Among those not attending, there was no change (13% vs 14%, p=0.8). Of those attending, there was no change in their perceived role in screening decisions, while the proportion responding correctly to a clinical vignette increased (88-99%, p<0.001).
An interactive training seminar increased the proportion of physicians with the intention to prescribe FIT and colonoscopy in equal proportions
Ecosystem modeling to evaluate the ecological sustainability of small-scale fisheries: A case study from El Hierro, Canary Islands
This paper examines various fishery management scenarios based on the recovery of small-scale fisheries (SSF) following a submarine volcanic eruption in 2011 in El Hierro Island (Canary Islands, Spain). After this catastrophic event, the SSF composition of La Restinga fishing community was affected by socio-economic and demographic changes. The uncertainty derived from this situation provides an opportunity to evaluate the fisheries’ sustainability and advice on different management options under an ecosystem-based approach. The Ecopath with Ecosim modeling framework was used to build a model of El Hierro Island, where the versatile and traditional multispecies small-scale fleet of La Restinga operates. Our main goal is to improve traditional fisheries, based on the relevance of key local fisheries and multi-specific fishery strategies in the light of scientific knowledge. Temporal simulations for the next decade were analyzed by creating scenarios of alternative fishing effort distributions based on the fishing trends observed in El Hierro small-scale community of La Restinga after a natural hazard. The outcomes of this modeling prototype show the vulnerability of some littoral and demersal species, the resilience of migratory species, and the sustainability of SSF diversification practices. These results could develop an adaptive and co-management strategy with the local fishing community to preserve the small-scale fishing system and marine resources.En prens
Fonética y fonología de los movimientos melódicos en el habla rural de Cuba y Venezuela
Este trabajo es una aportación del proyecto Estudio comparativo de la entonación y del acento en zonas fronterizas del español (FFI2014-52716-P). En esta ocasión se describen las características melódicas de un conjunto de oraciones declarativas e interrogativas absolutas extraídas de un corpus formal emitido por mujeres de zonas rurales de Cuba y Venezuela. En la elección de los puntos de encuesta hemos seguido las propuestas de división dialectal para ambos países realizadas por García Riverón (1986-1996) y por Mora (1996 y 1997). El análisis se realiza con subrutinas de MatLab (López-Bobo et al.) y los valores absolutos de F0 se relativizan en semitonos, determinando su importancia perceptiva (umbral diferencial de 1,5 semitonos: Rietveld y Gussenhoven). El análisis realizado nos ha permitido hacer un estudio fonético-fonológico que muestra principalmente que en la modalidad interrogativa se dan diferencias entre las zonas rurales y las urbanas analizadas en trabajos precedentes (Dorta).This work is a contribution to the Project Comparative Study of Intonation and Accent in borderlands of the Spanish Language (FFI2014-52716-P). In this paper we describe the melodic characteristics of a set of neutral declarative and absolute interrogative sentences, which have been extracted from a formal corpus uttered by women from rural areas of Cuba and Venezuela. While choosing the test sites, we have followed the proposed dialectal divisions by García Riverón (1988) and Mora (1996 y 1997). The analyses are performed using MatLab sub-routines (López-Bobo et al.). F0 absolute values are relativized into semitones, and their perceptive importance is determined above the 1.5 semitone differential threshold (Rietveld/Gussenhoven). These analyses have allowed us to carry out a phonetic-phonologic study that shows, among other results, differences in the interrogative modality that separate the rural areas from other urban areas that have been analysed in earlier studies (Dorta)
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