345 research outputs found
Condition and recruitment of Aristeus antennatus beyond fishing ground (to depths of 2200 m) in the Mediterranean: relationship with environmental factors
Depth relationships and seasonal trends in the biological condition and recruitment of the red shrimp Aristeus antennatus have been analyzed along down to 2300 m, over all the slope in the Balearic Basin (western Mediterranean). The analysis is based on a composite year (2008-2012 period) and identifies environmental causes of the trends. We found good reproductive and general biological condition of A. antennatus (Gonado-somatic index, GSI) at 800-1300 m in summer (June-July), depths below the fishing grounds. Mating and spawning were at depths below the more saline waters of the Levantine Intermediate water mass. Recruits Smallest juveniles (recruits, ca. 1 yr age) were exclusively distributed below 1000 m, associated with high near-bottom O2 concentration, low turbidity and high C/N in sediments implying favourable trophic conditions. A seasonal migratory pattern is suggested for females, which move shallower to the upper slope during periods of water-mass homogeneity (autumn-winter) to feed in canyons, increasing their energy reserves (hepatic gland weight, HSI). Females move downslope (800-1100 m) to spawn (high GSI) during periods of water mass stratification (late spring-summer). HSI of A. antennatus females decreased linearly with depth down the slope in February and in October-November, i.e., before and after the reproductive period. This nutritional condition of females in these periods is consistent with more consumption of benthic prey (ophiuroids, polychaetes, Calocaris macandreae) at the canyon heads (Cartes, 1994) in late autumn and winter. Our results confirm/suggest: i) how important it is to study the biology of deep-sea species over the whole depth range they inhabit and not only over fishing grounds, and ii) that changes in environmental conditions linked to the progressive warming of Mediterranean Deep Water (WMDW) with a parallel increase of salinity could provoke a decrease of O2 in water masses at below 1000 m, affecting A. antennatus recruitment and its life cycle, which is extensible to other deep-sea specie
Geological, geophysical and geochemical structure of a fault zone developed in granitic rocks: Implications for fault zone modeling in 3-D
The structure of a fault zone developed in
granitic rocks can be established on the basis of the spatial
variability of geological, geophysical and geochemical
parameters. In the North Fault of the Mina Ratones area
(SW Iberian Massif, Spain), fault rocks along two studied
traverses (SR-2 and SR-3 boreholes) exhibit systematic
changes in mineralogy, geochemistry, fabrics and microstructures
that are related to brittle deformation and
alteration of granite to form cataclasite and subsequent
gouge. The spatial distribution and intensity of these
changes suggest a North Fault morphology that is
consistent with the fault-core/damage-zone model proposed
by Chester et al. (1993) to describe a fault zone
architecture. North Fault damage zone thickness can be
defined by the development of mechanically related
mesoscopic faults and joints, that produce a Fracture
Index (FI)>10. High FI values are spatially correlated
with relative low seismic velocity zones (VP<5 km/s and
VS<2.5 km/s in the well-logs), more probably related to a
high concentration of fractures and geochemical alteration
produced by meteoric water-granite interaction along
fault surfaces. This correlation is the base of a geostatistical
model proposed in the final part of this study to
image the fault zone architecture of a granitic massif
Some applications of the bootstrap in Spanish Discards Sampling Scheme
Herein we propose a nested boostrap scheme to explore di erent sources
of variability in discard data. The proposed tool resamples on trips, hauls
within trips and lengthclasess within hauls to include all sources of variability identified in the Spanish DCR sampling program scheme. Megrim
(Lepidorhombus wiffiagonis) and Hake (Merluccius merluccius) discard
data collected in 2008 from OTB-51 metier operating in ICES Division
VI - VII, and Mediterranea DEF-Southern metier operating in the GSA
6S area were considered as case studies. Bootstrap Error and Coeficients
of Variation associated to mean discards per trip were obtained and compared with asymptotic estimates. Furthermore, we use the bootstrap to
quantify the contribution of the given sources of variability to global variability, and to assess simulated sampling scenarios differing each others
in sampling effort. The last application of this method is for detecting
outliers in 2008 sampled units (Trips). The good performance of the bootstrap method validates its use to obtain reliable error estimates in further
regression and/or classiffication studies on discard data
Mycobacterial aminoglycoside acetyltransferases: a little of drug resistance, and a lot of other roles
Aminoglycoside acetyltransferases are important determinants of resistance to aminoglycoside antibiotics in most bacterial genera. In mycobacteria, however, aminoglycoside acetyltransferases contribute only partially to aminoglycoside susceptibility since they are related with low level resistance to these antibiotics (while high level aminoglycoside resistance is due to mutations in the ribosome). Instead, aminoglycoside acetyltransferases contribute to other bacterial functions, and this can explain its widespread presence along species of genus Mycobacterium. This review is focused on two mycobacterial aminoglycoside acetyltransferase enzymes. First, the aminoglycoside 2'-N-acetyltransferase [AAC(2')], which was identified as a determinant of weak aminoglycoside resistance in M. fortuitum, and later found to be widespread in most mycobacterial species; AAC(2') enzymes have been associated with resistance to cell wall degradative enzymes, and bactericidal mode of action of aminoglycosides. Second, the Eis aminoglycoside acetyltransferase, which was identified originally as a virulence determinant in M. tuberculosis (enhanced intracellular survival); Eis protein in fact controls production of pro-inflammatory cytokines and other pathways. The relation of Eis with aminoglycoside susceptibility was found after the years, and reaches clinical significance only in M. tuberculosis isolates resistant to the second-line drug kanamycin. Given the role of AAC(2') and Eis proteins in mycobacterial biology, inhibitory molecules have been identified, more abundantly in case of Eis. In conclusion, AAC(2') and Eis have evolved from a marginal role as potential drug resistance mechanisms into a promising future as drug targets
Effect of preharvest fruit bagging on fruit quality characteristics and incidence of fruit physiopathies in fully irrigated and water stressed pomegranated trees
BACKGROUND: This report studied the response of pomegranate fruit under full irrigation (FI) and water stress (WS) conditions to bagging with externally glossy single layer cellulosic paper bags open at the bottom from the end of fruit thinning to harvest time. RESULTS: Bagging decreased fruit size and the maturity index, and increased antioxidant activity in FI conditions. Moreover, fruit bagging substantially reduced the incidence of peel sunburn in both irrigation conditions. CONCLUSION: The delay in fruit growth and ripening as a result of pomegranate fruit bagging is outweighed by the very important commercial benefit in terms of the reduced incidence of peel sunburn and the increase in fruit antioxidant activity
The Motor Dysfunction Seen in Isolated REM Sleep Behavior Disorder.
BACKGROUND: Isolated Rapid Eye Movement (REM) sleep Behavior Disorder (iRBD) requires quantitative tools to detect incipient Parkinson's disease (PD). METHODS: A motor battery was designed and compared with the Movement Disorder Society-Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS-III) in people with iRBD and controls. This included two keyboard-based tests (BRadykinesia Akinesia INcoordination tap test and Distal Finger Tapping) and two dual tasking tests (walking and finger tapping). RESULTS: We included 33 iRBD patients and 29 controls. The iRBD group performed both keyboard-based tapping tests more slowly (P < 0.001, P = 0.020) and less rhythmically (P < 0.001, P = 0.006) than controls. Unlike controls, the iRBD group increased their walking duration (P < 0.001) and had a smaller amplitude (P = 0.001) and slower (P = 0.007) finger tapping with dual task. The combination of the most salient motor markers showed 90.3% sensitivity for 89.3% specificity (area under the ROC curve [AUC], 0.94), which was higher than the MDS-UPDRS-III (minus action tremor) (69.7% sensitivity, 72.4% specificity; AUC, 0.81) for detecting motor dysfunction. CONCLUSION: Speed, rhythm, and dual task motor deterioration might be accurate indicators of incipient PD in iRBD. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
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