354 research outputs found

    Pinctada imbricata radiata in the Balearic Archipelago

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    The presence of Pinctada imbricata radiata (rayed pearl oyster) was explored in the Bay of Palma (Balearic Archipelago, NW Mediterranean Sea) by means of Rapid Assessment Surveys (RAS). Forty-three specimens were found in rocky substrates from recreational marinas and neighbouring natural habitats, including Cabrera National Park. Average hinge length was 26.8 ± 13.3 mm and average shell height was 28.6 ± 16.2 mm; a maximum size of 55.6 × 55.9 mm was measured. The main occurrence of the exotic oyster in marinas, and also far away in Cabrera, points to maritime transport as the primary introduction vector; whereas records in the adjacent natural habitats suggest secondary spread by natural dispersal has occurred. Considering the populations of P. imbricata radiata documented in the Balearic Archipelago, the bivalve seems to be well established in the area. The study explores the potential of RAS as early detection tools for invasive species along the coastline, and recommends further assessment on the ecological impact of P. imbricata radiata in marine protected areas.En prens

    The molecular gas content of the Pipe Nebula I. Direct evidence of outflow-generated turbulence in B59?

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    The Pipe Nebula is a molecular cloud hosting the B59 region as its only active star-forming clump. While the particular importance of outflows in active star forming regions is subject of debate, the quiet nature of the gas in B59 makes it a good site to directly see the impact of protostellar feedback on the quiescent dense gas. Using HARP at the JCMT, we mapped the B59 region with the J=3-2 transition of 12CO to study the kinematics and energetics of the outflows, and 13CO and C18O to study the overall dynamics of the ambient cloud, the physical properties of the gas, and the hierarchical structure of the region. The B59 region has a total of 30Msun of cold and quiescent material, mostly gravitationally bound, with narrow line widths throughout. Such low levels of turbulence in non-star-forming sites of B59 are indicative of the intrinsic initial conditions of the cloud. On the other hand, close to the forming protostars the impact of the outflows is observed as a localised increase of both line widths from 0.3 to 1 km/s, and 13CO excitation temperatures by 2-3K. The impact of the outflows is also evident in the low column density material which shows signs of being pushed, shaped and carved by the outflow bow shocks as they pierce their way out of the cloud. Much of this structure is readily apparent in a dendrogram analysis of the cloud. The low mass of B59 together with its intrinsically quiescent gas and small number of protostars, allows the identification of specific regions where the outflows from the embedded sources interact the dense gas. Our study suggests that outflows are an important mechanism for injecting and sustaining supersonic turbulence at sub-parsec size scales. We find that less than half of the outflow energy is deposited as turbulent energy of the gas, however this turbulent energy is sufficient to slow down the collapse of the region.Comment: Accepted for publication in A&

    Establecimiento de la ostra perlífera Pinctada imbricata radiata (Leach, 1814) en el Archipiélago Balear

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    The presence of Pinctada imbricata radiata has been explored in the Bay of Palma (Balearic Archipelago, NW Mediterranean Sea) by means of Rapid Assessment Surveys (RAS). Forty three specimens were found in rocky substrates from recreational marinas and neighbouring natural habitats, including Cabrera National Park. The main occurrence of the exotic oyster in marinas, and also faraway in Cabrera, points to maritime transport as the primary introduction vector; whereas records in the adjacent natural habitats suggest secondary spread by natural dispersal. Considering the populations of P. imbricata radiata documented in the Balearic Archipelago, the bivalve seems to be well established in the area. The study also explores the potential of RAS as early detection tool for invasive species along the coastline

    The Small-Scale Physical Structure and Fragmentation Difference of Two Embedded Intermediate Mass Protostars in Orion

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    Intermediate-mass (IM) protostars, the bridge between the very common solar-like protostars and the more massive, but rarer, O and B stars, can only be studied at high physical spatial resolutions in a handful of clouds. In this paper, we present and analyze the continuum results from an observing campaign at the Submillimeter Array (SMA) targeting two well-studied IM protostars in Orion, NGC 2071 and L1641 S3 MMS 1. The extended SMA (eSMA) probes structure at angular resolutions up to 0".2, revealing protostellar disks on scales of ∼200 AU. Continuum flux measurements on these scales indicate that a significant amount of mass, a few tens of M_⊙, is present. Envelope, stellar, and disk masses are derived using compact, extended, and eSMA configurations and compared against spectral energy distribution fitting models. We hypothesize that fragmentation into three components occurred within NGC 2071 at an early time, when the envelopes were less than 10% of their current masses, e.g., <0.5 M. No fragmentation occurred for L1641 S3 MMS 1. For NGC 2071, evidence is given that the bulk of the envelope material currently around each source was accreted after the initial fragmentation. In addition, about 30% of the total core mass is not yet associated to one of the three sources. A global accretion model is favored and a potential accretion history of NGC 2071 is presented. It is shown that the relatively low level of fragmentation in NGC 2071 was stifled compared to the expected fragmentation from a Jeans argument. Similarly, the lack of fragmentation in L1641 S3 MMS 1 is likely due to similar arguments

    The cold-sensing ion channel TRPM8 regulates central and peripheral clockwork and the circadian oscillations of body temperature

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    [Abstract] Aim: Physiological functions in mammals show circadian oscillations, synchronized by daily cycles of light and temperature. Central and peripheral clocks participate in this regulation. Since the ion channel TRPM8 is a critical cold sensor, we investigated its role in circadian function. Methods: We used TRPM8 reporter mouse lines and TRPM8-deficient mice. mRNA levels were determined by in situ hybridization or RT-qPCR and protein levels by immunofluorescence. A telemetry system was used to measure core body temperature (Tc). Results: TRPM8 is expressed in the retina, specifically in cholinergic amacrine interneurons and in a subset of melanopsin-positive ganglion cells which project to the central pacemaker, the suprachiasmatic nucleus (SCN) of the hypothalamus. TRPM8-positive fibres were also found innervating choroid and ciliary body vasculature, with a putative function in intraocular temperature, as shown in TRPM8-deficient mice. Interestingly, Trpm8-/- animals displayed increased expression of the clock gene Per2 and vasopressin (AVP) in the SCN, suggesting a regulatory role of TRPM8 on the central oscillator. Since SCN AVP neurons control body temperature, we studied Tc in driven and free-running conditions. TRPM8-deficiency increased the amplitude of Tc oscillations and, under dim constant light, induced a greater phase delay and instability of Tc rhythmicity. Finally, TRPM8-positive fibres innervate peripheral organs, like liver and white adipose tissue. Notably, Trpm8-/- mice displayed a dysregulated expression of Per2 mRNA in these metabolic tissues. Conclusion: Our findings support a function of TRPM8 as a temperature sensor involved in the regulation of central and peripheral clocks and the circadian control of Tc.Ministerio de Ciencia e Innovación (España); RT2018-099995-B100Ministerio de Ciencia e Innovación (España); AEI/10.13039/501100011033Generalitat Valenciana; PROMETEO/2021/031Ministerio de Asuntos Económicos y Transformación Digital (España); BES-2011-04706

    Propiedades Fisicoquímicas De Suelos Cultivados Con Asparagus Officinalis En La Región Árida Del Noroeste De México

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    In the agriculture of arid zones, the inadequate soil management has generated changes in their quality and sustainability, affecting the structure and physicochemical conditions which reduce crop yields; based on the above, is consider as a vital importance the analyses of soil and plants because they provide information, current and accurate, which can be useful to take decisions in relation to soil fertility and plant nutrition. The inappropriate handling and amount of fertilizers in asparagus in the arid region of the Northwest of Mexico, has caused low yields. The aim of this study consisted to analyze soil in seven of the thirteen sub regions of the agricultural coast of Caborca, Sonora, where the asparagus crop has been planted for more than 10 years. The analyzes performed were: percentage of saturation, pH, electrical conductivity (CE), soil texture Nitrogen (NO3), P, K, Na, Ca, Mg and cation exchange capacity. The results showed high levels of Nitrogen and Potassium in almost all the studied sites; on contrary Phosphorus, Calcium and Magnesium, presented values below of the recommended and Electrical conductivity above 5.5. mmhos/ cm. The integration of this information allows appropriate technical advice, to achieve the balance of nutrients, such as to avoid unnecessary costs in fertilizers that the plant might can not take, in addition to the resulting contamination of soil to leach these products

    Nutritional characteristics of different types of eggs

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    Objective: To analyze 5 types of poultry eggs (chicken, turkey, ostrich, duck and quail) to compare their nutritional characteristics and sensory properties. Design/ Methodology/ Approach: A physical analysis was performed: weight of the entire egg (weight and proportion of the albumin, yolk and shell) length and width of the entire egg, shape index, shell color, and yolk color, nutritional (determination of raw fat, protein, dry matter and ashes) and in sensory adaptation (measured through hedonic testing of adaptability through the arrangement of nine points to an individualized quantity of 97). Different types of egg used: chicken, turkey, ostrich, duck and quail. Results: The egg containing the most amount of protein was that of the duck (13.02 ± 0.46 %), while the sample containing the lowest result was that of the ostrich (9.47 ± 0.27 %). The type of egg that contained the fattest level was the duck (10.31 ± 0.75 %); on the other hand, the type of egg that demonstrated the least amount of fat was that of the chicken egg (8.28 ± 0.39 %). Results/ Findings/ Conclusion: Even though some physical differences exist in all types of eggs, they are similar and there is minimal variation in terms of their nutritional value. Therefore, these different types of eggs can be applied for consumption as substitutes for chicken eggs and as an alternative source of protein. Limitations of the study/ Implications: Lack of previous research in regard to comparisons of the types of analyzed eggs

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Combined search for the quarks of a sequential fourth generation

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    Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

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    The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO
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