982 research outputs found

    Ontogenetic foraging activity and feeding selectivity of the Brazilian endemic parrotfishScarus zelindae

    Get PDF
    Parrotfish are fundamental species in controlling algal phase-shifts and ensuring the resilience of coral reefs. Nevertheless, little is known on their ecological role in the south-western Atlantic Ocean. The present study analysed the ontogenetic foraging activity and feeding selectivity of the Brazilian endemic parrotfish Scarus zelindae using behavioural observation and benthic composition analyses. We found a significant negative relationship between fish size and feeding rates for S. zelindae individuals. Thus, terminal phase individuals forage with lower feeding rates compared to juveniles and initial phase individuals. The highest relative foraging frequency of S. zelindae was on epilithic algae matrix (EAM) with similar values for juveniles (86.6%), initial phase (88.1%) and terminal phase (88.6%) individuals. The second preferred benthos for juveniles was sponge (11.6%) compared with initial (4.5%) and terminal life phases (1.3%). Different life phases of S. zelindae foraged on different benthos according to their availability. Based on Ivlev's electivity index, juveniles selected EAM and sponge, while initial phase and terminal phase individuals only selected EAM. Our findings demonstrate that the foraging frequency of the endemic parrotfish S. zelindae is reduced according to body size and that there is a slight ontogenetic change in feeding selectivity. Therefore, ecological knowledge of ontogenetic variations on resource use is critical for the remaining parrotfish populations which have been dramatically reduced in the Southwestern Atlantic Ocean

    First Record Of Egg Sac Predation On A Wall Crab Spider Selenopidae (araneae) By The Wasp Camera Lunavenatrix Sp. N. (ichneumonidae, Cryptinae)

    Get PDF
    We report the first record of egg sac predation on the wall crab spider Selenops cocheleti by wasps of the genus Camera (Ichneumonidae: Cryptinae) with the description of a new species, as well as biological information on the wasp and the spider host. The rearing record and information presented herein are the first biological data for the genus.496579AMNH, American Museum of Natural History1501802, NSF, National Science FoundationSSB, Society of Systematic Biologist

    Magneto-optical trap for metastable helium at 389 nm

    Full text link
    We have constructed a magneto-optical trap (MOT) for metastable triplet helium atoms utilizing the 2 3S1 -> 3 3P2 line at 389 nm as the trapping and cooling transition. The far-red-detuned MOT (detuning Delta = -41 MHz) typically contains few times 10^7 atoms at a relatively high (~10^9 cm^-3) density, which is a consequence of the large momentum transfer per photon at 389 nm and a small two-body loss rate coefficient (2 * 10^-10 cm^3/s < beta < 1.0 * 10^-9 cm^3/s). The two-body loss rate is more than five times smaller than in a MOT on the commonly used 2 3S1 -> 2 3P2 line at 1083 nm. Furthermore, we measure a temperature of 0.46(1) mK, a factor 2.5 lower as compared to the 1083 nm case. Decreasing the detuning to Delta= -9 MHz results in a cloud temperature as low as 0.25(1) mK, at small number of trapped atoms. The 389 nm MOT exhibits small losses due to two-photon ionization, which have been investigated as well.Comment: 11 page

    Micro X-ray Fluorescence Imaging in a Tabletop Full Field-X-ray Fluorescence Instrument and in a Full Field-Particle Induced X-ray Emission End Station

    Get PDF
    A full field-X-ray camera (FF-XRC) was developed for performing the simultaneous mapping of chemical elements with a high lateral resolution. The device is based on a conventional CCD detector coupled to a straight shaped polycapillary. Samples are illuminated at once with a broad primary beam that can consist of X-rays or charged particles in two different analytical setups. The characteristic photons induced in the samples are guided by the polycapillary to the detector allowing the elemental imaging without the need for scanning. A single photon counting detection operated in a multiframe acquisition mode and a processing algorithm developed for event hitting reconstruction have enabled one to use the CCD as a high energy resolution X-ray detector. A novel software with a graphical user interface (GUI) programmed in Matlab allows full control of the device and the real-time imaging with a region-of-interest (ROI) method. At the end of the measurement, the software produces spectra for each of the pixels in the detector allowing the application of a least-squares fitting with external analytical tools. The FF-XRC is very compact and can be installed in different experimental setups. This work shows the potentialities of the instrument in both a full field-micro X-ray fluorescence (FF-MXRF) tabletop device and in a full field-micro particle induced X-ray emission (FF-MPIXE) end-station operated with an external proton beam. Some examples of applications are given as well

    The combined use of Pochonia chlamydosporia and plant defence activators - a potential sustainable control strategy for Meloidogyne chitwoodi

    Get PDF
    Sustainable strategies are required for control of the root-knot nematode Meloidogyne chitwoodi to reduce dependence on toxic chemical pesticides. The efficacy of the nematophagous fungus Pochonia chlamydosporia in biocontrol could be enhanced by integration with control measures that reduce initial nematode infestations. The use of foliar sprays with plant defence activators can reduce the susceptibility of potato plants to M. chitwoodi. This study assessed effects of combined soil application of P. chlamydosporia with foliar sprays of benzothiadiazole (BTH) or cis-jasmone on infection of potatoes by M. chitwoodi. Solanum tuberosum, cv. Désirée plants were grown in soil mixed with 5000 chlamydospores g-1 of soil, sprayed twice with BTH or cis-jasmone and inoculated with 300 M. chitwoodi second-stage juveniles. Forty-five days after inoculation, nematode reproduction, numbers of colony-forming units of the fungus g-1 of soil and g-1 of root, and egg parasitism were assessed by standard techniques. Foliar sprays of BTH or cis-jasmone combined with the fungus reduced nematode reproduction (P&lt;0.05, LSD). The presence of the fungus slightly increased the efficacy of cis-jasmone, as the number of eggs per egg mass was less in plants treated both with cis-jasmone and the fungus than in the plants treated only with the defence activator. The proportion of parasitized eggs was greater in the cis-jasmone treatment where rhizosphere colonisation was less, suggesting that P. chlamydosporia became a poorer rhizosphere coloniser but a more efficient nematode parasite. The addition of P. chlamydosporia to soil in combination with application of inducers of plant defence could be an alternative control strategy to be used against M. chitwoodi in potato

    Obese elderly women exhibit low postural stability: a novel three-dimensional evaluation system

    Get PDF
    OBJECTIVE: The aim of this study was to evaluate the multisegmental static postural balance of active eutrophic and obese elderly women using a three-dimensional system under different sensory conditions. METHODS: A cross-sectional study was conducted on 31 elderly women (16 eutrophic and 15 obese) aged 65 to 75 years. The following anthropometric measurements were obtained: weight, height, waist and hip circumference, and handgrip strength. The physical activity level was evaluated using the International Physical Activity Questionnaire. Body composition was measured using the deuterium oxide dilution technique. The Polhemus (R) Patriot (three-dimensional) equipment was used to measure the parameters of postural balance along the anteroposterior and laterolateral axes. The data acquisition involved one trial of 60 s to test the limit of stability and four trials of 90 s each under the following conditions: (1) eyes open, stable surface; (2) eyes closed, stable surface; (3) eyes open, unstable surface; and (4) eyes closed, unstable surface. RESULTS: For the limit of stability, significant differences were observed in the maximum anteroposterior and laterolateral displacement (p&lt;0.01) and in the parameter maximum anteroposterior displacement in the eyes closed stable surface condition (p&lt;0.01) and maximum anteroposterior and laterolateral displacement in the eyes open unstable surface (p&lt;0.01 and p = 0.03) and eyes closed unstable surface (p&lt;0.01 and p&lt;0.01) conditions. CONCLUSIONS: Obese elderly women exhibited a lower stability limit (lower sway area) compared with eutrophic women, leaving them more vulnerable to falls

    Engineering the BASHY Dye Platform toward Architectures with Responsive Fluorescence

    Get PDF
    A set of nine boronic-acid-derived salicylidenehydrazone (BASHY) complexes has been synthesized in good to very good chemical yields in a versatile three-component reaction. In an extension to previous reports on this dye platform, the focus was put on the electronic modification of the “vertical” positions of the salicylidenehydrazone backbone. This enabled the observation of fluorescence quenching by photoinduced electron transfer (PeT), which can be reverted by the addition of acid in organic solvent (OFF-ON fluorescence switching). The resulting emission is observed in the green-to-orange spectral region (maxima at 520–590 nm). In contrast, under physiological pH conditions in water, the PeT process is inherently decativated, thereby enabling the observation of fluorescence in the red-to-NIR region (maxima at 650–680 nm) with appreciable quantum yields and lifetimes. The latter characteristic supported the application of the dyes in fluorescence lifetime imaging (FLIM) of live A549 cells.This work was generously supported by the Portuguese Fundação para a Ciência e Tecnologia [grants PTDC/QUI-OUT/3989/2021 (P.G.); institutional grants UIDB/04138/2020 and UIDP/04138/2020 (iMed)], the Spanish Ministerio de Ciencia e Innovación [grants CTQ2017-89832-P, PID2020-119992GB-I00 (both to U.P.), and PID2019-104293GB-I00 (F.N.)], the Consejería de Universidad, Investigación e Innovación/Junta de Andalucía [grant P18-FR-4080 (U.P.)], and the Universidad de Huelva/Junta de Andalucía [UHU202070 (U.P.)]. The NMR spectrometers are part of the Portuguese National NMR Network (PT NMR) and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI, PORL, and FCT through PIDDAC). We also acknowledge the Supercomputing and Bioinformatics Centre (SCBI) of the University of Málaga for providing the computer resources used for the theoretical calculations

    DEGRADABILIDADE in vitro DA PROTEÍNA DE ESPÉCIES ARBÓREAS DO SEMI-ÁRIDO BRASILEIRO

    Get PDF
    This experiment was carried out to evaluate the protein degradability in vitro of arboreal plants from Brazilian semi-arid. The plants tested were angico (Anadenanthera colubrina), algaroba (Prosopis juliflora), espinheiro (Acacia glomerosa), juazeiro (Ziziphus joazeiro) and soybean meal, which had crude protein values of 22,5 16,0, 22,0, 19,0 and 38,0%, respectively. Samples (60 mg) were incubated with McDougal (8 ml) and inoculated ruminal fluid (2 ml). Aliquots (1 ml) were taking after 0, 6, 12, 24, 36 and 48 hours for analysis of ammonia, soluble protein and microbial protein. Soybean meal and the algaroba showed larger ammonia production and concentration of soluble protein compared to the other treatments. Soybean meal also displayed higher values for microbial protein. The treatment with angico was the one that displayed closed values towards soybean in regard to microbial protein, in spite of showing lesser ammonia production. The largest value of potential degradability 66,47%, was observed for the treatment with soybean meal, followed by the algaroba 46,27% and of the angico 45,20. Very low degradability was observed for the espinheiro and juazeiro, 19,16 e16,63%, respectively. Among the studied plants the angico and the algaroba were better sources of protein.O experimento teve como objetivo avaliar a degradabilidade in vitro da proteína de plantas arbóreas do semi-árido brasileiro e do farelo de soja. As plantas utilizadas foram angico (Anadenanthera colubrina), algaroba (Prosopis juliflora), espinheiro (Acacia glomerosa), juazeiro (Ziziphus joazeiro) e o farelo de soja, com valores de proteína bruta de 22,5 16,0, 22,0, 19,0 e 38,0%, respectivamente. Amostras de cada planta (60 mg) foram incubadas em 8 ml de meio tampão de McDougal, com adição de 2 ml de inóculo ruminal. Nos tempos 0, 6, 12, 24, 36 e 48 horas após a incubação foi retirada uma alíquota de 1,0 ml para análise de amônia, proteína solúvel e proteína microbiana. O farelo de soja e a algaroba proporcionaram maiores produção de amônia e concentração de proteína solúvel em relação aos outros alimentos, sendo que o farelo de soja apresentou maior valor de proteína microbiana. O tratamento com o angico foi o que mais se aproximou à soja com relação ao valor de proteína microbiana, apesar da sua menor produção de amônia. O maior valor de degradabilidade potencial 66,47 %, foi observado no tratamento com farelo de soja, seguidos dos tratamentos da algaroba 46,27% e angico 45,20%. Foram observados valores de degradabilidade muito baixos para o espinheiro e juazeiro, 19,16 e 16,63%, respectivamente. O angico e a algaroba apresentaram-se como melhores fontes de proteína entre as plantas avaliadas

    Pulsed Magnetic Field Measurements of the Composite Fermion Effective Mass

    Full text link
    Magnetotransport measurements of Composite Fermions (CF) are reported in 50 T pulsed magnetic fields. The CF effective mass is found to increase approximately linearly with the effective field BB^*, in agreement with our earlier work at lower fields. For a BB^* of 14 T it reaches 1.6me1.6m_e, over 20 times the band edge electron mass. Data from all fractions are unified by the single parameter BB^* for all the samples studied over a wide range of electron densities. The energy gap is found to increase like B\sqrt{B^*} at high fields.Comment: Has final table, will LaTeX without error

    Quantum phase gate with a selective interaction

    Get PDF
    We present a proposal for implementing quantum phase gates using selective interactions. We analize selectivity and the possibility to implement these gates in two particular systems, namely, trapped ions and Cavity QED.Comment: Four pages of TEX file and two EPS figures. Submitted for publicatio
    corecore