Resposta acústica de artes de pesca para captura de lula e ocultação à sondagem por golfinhos

Barreto, M., Gatta, M., & Lobo, V. (2022). Resposta acústica de artes de pesca para captura de lula e ocultação à sondagem por golfinhos. In I. H. (Ed.), Atas das 7.as Jornadas de Engenharia Hidrográfica / 2. as Jornadas Luso-Espanholas de Hidrografia (pp. 38-40). Instituto Hidrográfico. https://jornadas.hidrografico.pt/recursos/files/documentos/2022/7JEH-Livro_Atas.pdfA depredação por golfinhos das lulas ferradas nas toneiras da frota de pesca artesanal Micaelense, nos Açores, constitui um problema sócio-económico e de conservação marinha. Na hipótese da resposta das toneiras à sondagem acústica (ecolocalização) por parte dos golfinhos ser significativa, estas seriam um elemento auxiliar que lhes facilitaria a detecção e identificação. Uma mudança nas artes de pesca podia assim ajudar a minimizar os prejuizos causados. Para compreender a detectabilidade através de acústica submarina, caracterizámos a impedância dos materiais e a resposta das toneiras a sinais sonoros de banda curta percorrendo o intervalo espectral dos cliques de golfinhos. Dos ensaios realizados em configuração bi-estática no tanque anecóico, resultam sonogramas, curvas de resposta em frequência e valores quantitativos (target strength) que nos permitem hierarquizar reflectividades e distâncias de detecção. Permitem também comparar comportamento de ecos e sugerir medidas para atenuar a reflectividade (aumentando a furtividade), originando recomendações aos pescadores.publishersversionpublishe

A comparison between elite swimmers and kayakers on upper body push and pull strength and power performance

The aim of the present study was to compare the load-power curve expressed at bench press (PR) and prone bench pull (PU) between elite swimmers and kayakers. Another aim was to calculate the strength and power PR/PU ratio in the same populations. Fifteen elite swimmers (SW: age = 23.8 ± 2.9 y; body mass = 82.8 ± 5.6 kg; body height = 184.1 ± 4.6 cm) and 13 elite kayakers (KA: age = 23.8 ± 2.9 y; body mass = 91.0 ± 3.5 kg; body height = 180.1 ± 5.4 cm) were assessed for PR 1RM and PU 1RM. They were then assessed for power produced at 40, 60 and 80% of 1RM in both PR and PU. The area under the load-power curve (AUC) and PR/PU ratios were calculated for both the SW and KA groups. The KA group showed significantly higher PR1RM (+18.2%; p = 0.002) and PU1RM (+25.7%; p < 0.001) compared to the SW group. Significant group differences were also detected for PUAUC (p < 0.001) and for the PR/PU power ratio (p < 0.001). No significant group differences were detected for PRAUC (p = 0.605) and for the PR/PU strength ratio (p = 0.065; 0.87 and 0.82 in SW and KA, respectively). The present findings indicate that elite KA were stronger and more powerful than elite SW in the upper body. Not consistently with other athletic populations, both KA and SW athletes were stronger and more powerful in upper body pull compared to push moves

Inference of gene regulatory networks and compound mode of action from time course gene expression profiles.

MOTIVATION: Time series expression experiments are an increasingly popular method for studying a wide range of biological systems. Here we developed an algorithm that can infer the local network of gene-gene interactions surrounding a gene of interest. This is achieved by a perturbation of the gene of interest and subsequently measuring the gene expression profiles at multiple time points. We applied this algorithm to computer simulated data and to experimental data on a nine gene network in Escherichia coli. RESULTS: In this paper we show that it is possible to recover the gene regulatory network from a time series data of gene expression following a perturbation to the cell. We show this both on simulated data and on a nine gene subnetwork part of the DNA-damage response pathway (SOS pathway) in the bacteria E. coli

Oxidation and antioxidant status: effects on shelf-life of meat from Limousine cattle fed with supplements of alpha-tocopherol

The purpose of this study was to evaluate the antioxidant status of meat from cattle fed diets supplemented with vitamin E (α-tocopherol acetate) during the finishing period and to evaluate the effect of this treatment on meat shelf-life. Twenty purebred Limousine calves reared in the same farm, were randomly selected, divided into control group (n=10) and treated group (n=10) and fed a total mixed ration: treated group received a supplementation of vitamin E (900 mg/kg of CMF) for a period of 150 days before slaughter. Meat quality was evaluated by the following analyses: pH, water holding capacity (drip loss), colour (L*, a*, b*, C*, H*), chemical forms of myoglobin, substances reactive to thiobarbituric acid (MDA) and enzymatic antioxidant activity (superoxide dismutase, catalase and glutation peroxidase). Dietary vitamin E supplementation had a positive effect on water holding capacity; in the control group a considerable increase in drip loss from the 2nd to 6th day of conservation was observed (2.83% vs 7.54%), while in the treated group during the same time period this increase appeared to be much more gradual and occurred to a lesser degree (2.31% vs 4.15%). Moreover, administration of vitamin E led to greater stability of colorimetric coordinates and reduced discoloration of the longissimus dorsi muscle during conservation as indicated by the redness a* (control: 23.85 and 23.87 vs 19.34 at 2h, 2 and 6 days, respectively; treated: 24.88, 23.91 and 24.01 at 2h, 2 days and 6 days, respectively) and in the Chroma* (control: 26.89 and 26.77 vs 21.90 at 2h, 2 days and 6 days, respectively; treated: 27.67, 26.57 and 26.77 at 2h, 2 and 6 days, respectively). Superoxide dismutase activity was significantly greater in the meat from cattle treated with vitamin E compared to that observed in the meat from controls (0.204 vs 0.167). The study showed that vitamin E supplementation in the finishing diets of calves caused only slight modifications in the antioxidant status of the meat; however, it positively influenced several qualitative characteristics which appeared to be more stable over time, thus extending the shelf-life of the meat

Comparative compressional behavior of chabazite with Li+, Na+, Ag+, K+, Rb+, and Cs+ as extra-framework cations

The high-pressure behavior of monovalent-cation-exchanged chabazites was investigated by means of in situ synchrotron X-ray powder diffraction with a diamond-anvil cell, and using water as penetrating pressure-transmitting medium, up to 5.5 GPa at room temperature. In all cases, except for Na-containing chabazites, a phase transition from the original rhombohedral (R3m) to triclinic symmetry (likely P1) was observed in the range between 3.0 GPa and 5.0 GPa. The phase transition is accompanied by an abrupt decrease of the unit-cell volume by up to 10%. Evidence of pressure-induced hydration (PIH), i.e., P-induced penetration of H2O molecules through the zeolitic cavities, was observed, as reflected by the incompressibility of the cation-exchanged chabazites, which is governed by the distribution of the extra-framework cations. The reversibility of the PIH and P-induced phase transitions in the high-pressure behavior of the cation-exchanged chabazites are discussed in the context of the role played by the chemical nature and bonding configuration of the extra-framework cations, along with that of the H2O content at room conditions

Strain partitioning in host rock controls LREE release from allanite-(Ce) in subduction zones

Combined microstructural, mineral chemical, X-ray maps, and X-ray single-crystal diffraction analyses are used to reveal the rheological behaviour of individual grains of magmatic allanite relicts hosted in variably deformed metagranitoids at Lago della Vecchia (inner part of the Sesia-Lanzo Zone, Western Alps, Europe), which experienced high pressure and low temperature metamorphism during the Alpine subduction. X-ray single crystal diffraction shows that none of the allanite crystals, irrespective of the strain state of the host rock, record any evidence of plastic deformation (i.e., intracrystalline deformation), as indicated by the shape of the Bragg diffraction spots, the atomic site positions, and their displacement around the centre of gravity. On the contrary, strong plastic deformation affected matrix minerals, such as quartz, white mica, and feldspar of the hosting rocks, during the development of the Alpine eclogitic- and blueschist-facies metamorphism. Despite the strain-free atomic structures of allanite, different patterns of chemical zoning, as a function of strain accumulated in the rock matrix, are observed. Since allanite occurs in magmatic and metamorphic rocks and it is stable at high pressure and low temperature conditions, we infer that allanite could behave as one of the main carriers of light-rare-earth-elements into the mantle wedge during subduction of continental crust. In particular, the release of light-rare-earth-elements from allanite, under high pressure conditions in subduction zones, is facilitated by high strain accumulated in the host rock

H-bonding in lazulite: a single-crystal neutron diffraction study at 298 and 3 K

The crystal structure and crystal chemistry of a lazulite from Crosscut Creek (Kulan Camp area, Dawson mining district, Yukon, Canada) was investigated by electron microprobe analysis in wavelength-dispersive mode (EMPA) and single-crystal neutron diffraction at 298 and 3 K. Its empirical formula, based on EMPA data, is: (Mg0.871Fe0.127)\u3a30.998Al2.030(P1.985Ti0.008Si0.007O4)2(OH)2. The neutron diffraction experiments at room and low T proved that the H-free structural model of lazulite previously reported, on the basis of X-ray structure refinement, is correct: the building unit of the lazulite structure consists of a group of three face-sharing (Al-octahedron) + (Mg,Fe-octahedron) + (Aloctahedron), connected to the adjacent one via a corner-shared OH-group and two corner-shared oxygen sites of the P-tetrahedron, to form a dense 3D-edifice. Only one crystallographically independent H site occurs in the structure of lazulite, forming a hydroxyl group with the O5 oxygen, with O5\u2013H = 0.9997 \uc5 at room temperature (corrected for riding motion effect). The H-bonding scheme in the structure of lazulite is now well defined: a bifurcated bonding scheme occurs with the O4 and O2 oxygen sites as acceptors. The two H-bonds are energetically different, as shown by their bonding geometry: the H-bond with the O2 site as acceptor is energetically more favorable, being O5\u2013H\ub7\ub7\ub7O2 = 152.67(9)\ub0, O5\ub7\ub7\ub7O2 = 3.014(1) \uc5 and H\ub7\ub7\ub7O2 = 2.114(1) \uc5, whereas that with O4 as acceptor is energetically more costly, being O5\u2013H\ub7\ub7\ub7O4 = 135.73(8)\ub0, O5\ub7\ub7\ub7O4 = 3.156(1) \uc5 and H\ub7\ub7\ub7O4 = 2.383(1) \uc5, at room temperature. No T-induced phase transition occurs within the T-range investigated. At low temperature, the O5\u2013H\ub7\ub7\ub7O2 bond is virtually identical to the room-T one, whereas the effects of T on O5\u2013H\ub7\ub7\ub7O4 are more pronounced, with significant differences of the Odonor\ub7\ub7\ub7Oacceptor and H\ub7\ub7\ub7Oacceptor distances. The experimental findings of this study do not support the occurrence of HPO4 or H2PO4 units into the structure of lazulite, recently reported on the basis of infrared and Raman spectra

Ettringite at high pressure: structure evolution and elastic behaviour

In order to predict the elastic properties of the complex multi-component Portland cement, database of the thermodynamic parameters of the main constituents is needed. Ettringite (ideally Ca6Al2(SO4)3(OH)12\ub727H2O, with a=b \uf07e 11.21 and c \uf07e 21.43 \uc5, Sp. Gr. P31c) is a common crystalline phases in Portland cements. It contains more than 45 wt% of H2O. In the early hydration stages, the crystallization of ettringite governs the set rate of the highly reactive Ca3Al2O6 phase (also known as \u201cC3A\u201d), whereas in aged cements its formation is associated to degradation processes1. The crystal structure of ettringite is rather complex and it consists of [Ca3[Al(OH)6]\ub712H2O]-columns (in which Al(OH)6-octahedra are alternated with triplets of Ca(OH)4(OH2)4-polyhedra) and sulphate groups connected by a complex H-bonding net2. Previous studies on the behavior of ettringite at high pressure reported only the isotropic compressional behavior of ettringite 3,4. Because of that, the linear bulk moduli (Ka and Kc) and a full description of the deformation mechanisms at the atomic scale are still missing. We compressed a single crystal of ettringite up to 4.2 GPa by means of in-situ synchrotron X-ray diffraction, using a diamond-anvil cell and the mix methanol:ethanol (4:1) as P-transmitting fluid. Ettringite shows a marked anisotropic compressional pattern (Ka 21(1) GPa, Kc 47(1) GPa), which dramatically changes at P>3 GPa (Fig. 1). At P>3 GPa, the bulk modulus KV of ettringite drops from 26.6(5) to 10.4(8) GPa. Such a softening is governed by the structural changes which affect mainly the elastic behavior on the ab plane (Ka drops from 21(1) to 7.3(8) GPa whereas Kc decreases only moderately). The structure refinements reveal that the elastic softening reflects the collapse of the H-bonding net, due an average decrease of the Odonor\ub7\ub7\ub7Oacceptor distances (up to 0.20 \uc5 in some cases), which mainly affect the interaction between the sulphate groups and the Ca(OH)4(OH2)4-polyhedra lying in the ab plane

High-pressure behavior of synthetic mordenite-Na: an in situ single-crystal synchrotron X-ray diffraction study

The high-pressure behavior of a synthetic mordenite- Na (space group: Cmcm or Cmc21) was studied by in situ single-crystal synchrotron X-ray diffraction with a diamond anvil cell up to 9.22(7) GPa. A phase transition, likely displacive in character, occurred between 1.68(7) and 2.70(8) GPa, from a C-centered to a primitive space group: possibly Pbnm, Pbnn or Pbn21. Fitting of the experimental data with III-BM equations of state allowed to describe the elastic behavior of the high-pressure polymorph with a primitive lattice. A very high volume compressibility [KV0 = 25(2) GPa, \u3b2V0 = 1/KV0 = 0.040(3) GPa\u20131; KV\u2032 = ( 02KV/ 02P)T = 2.0(3)], coupled with a remarkable elastic anisotropy (\u3b2b > > \u3b2c > \u3b2a), was found. Interestingly, the low-P and high-P polymorphs show the same anisotropic compressional scheme. A structure collapse was not observed up to 9.22(7) GPa, even though a strong decrease of the number of observed reflections at the highest pressures suggests an impending amorphization. The structure refinements performed at room-P, 0.98(2) and 1.68(7) GPa allowed to describe, at a first approximation, the mechanisms that govern the framework deformation in the low-P regime: the bulk compression is strongly accommodated by the increase of the ellipticity of the large 12-membered ring channels running along [001]