288 research outputs found

    Caracterización palinológica de las especies de orégano de los géneros Lippia (Verbenaceae) y Poliomintha (Lamiaceae) de Nuevo León

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    RESUMEN En México, dos géneros de orégano destacan en importancia comercial: Lippia (Verbenaceae) y Poliomintha (Lamiaceae), y crecen en las zonas áridas y semiáridas del país. En la identificación de las especies de orégano, generalmente, se toman en cuenta caracteres morfológicos de hojas, color de las flores, tipo de fruto, entre otras; pero no se consideran las características morfológicas del polen. En el presente estudio, se prepararon laminillas con la técnica de acetólisis; la descripción de los granos de polen se realizó con microscopía óptica a una magnificación de 400x y microscopía de barrido. Se midieron el eje polar, eje ecuatorial, diámetro, largo y ancho de las aperturas, grosor exina, tamaño de lumen y muro, tamaño y tipo del área polar. En L. graveolens se encontró que el polen es tricolporado y la ornamentación de la exina psilada-perforada, presentándose una ligera variación en el tamaño de los granos para las diferentes localidades. Para el género Poliomintha, las especies presentan exina reticulada y hexacolpados y variación en el tamaño de los granos, siendo los de mayor tamaño para P. bustamanta. ABSTRACT There are two genus of commercial importance among the varieties of oregano in Mexico, Lippia (Verbenaceae) and Poliomintha (Lamiaceae), which both grow in arid and semi-arid regions of the country. For the identification of the species of oregano, the morphological characteristics of the leaves, the color of the flower, and the fruit type, among other characteristics, are generally taken into account; but it is not usual to consider the morphological characteristics of the pollen grains. In the present study microscopy slides were prepared by the acetolysis technique. The description of the pollen grains was performed using light microscopy at a magnification of 400x and scanning electron microscopy. We measured the polar axis, equatorial axis, diameter, length and width of the openings, exine thickness, lumen size, wall thickness, and type of polar area. Pollen grains in L. graveolens were found to be tricolporate while the ornamentation of the exine was psilate-perforated, showing a slight variation in the size of the grains from different locations. For the species of the genus Poliomintha, a hexacolpate and reticulate exine was observed as well as variations in the grain size, with P. bustamanta being the largest

    Measurements of long-range near-side angular correlations in √sNN=5TeV proton-lead collisions in the forward region

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    Two-particle angular correlations are studied in proton-lead collisions at a nucleon–nucleon centre-of-mass energy of √sNN=5TeV, collected with the LHCb detector at the LHC. The analysis is based on data recorded in two beam configurations, in which either the direction of the proton or that of the lead ion is analysed. The correlations are measured in the laboratory system as a function of relative pseudorapidity, η, and relative azimuthal angle, φ, for events in different classes of event activity and for different bins of particle transverse momentum. In high-activity events a long-range correlation on the near side, φ≈0, is observed in the pseudorapidity range 2.0 <η<4.9. This measurement of long-range correlations on the near side in proton-lead collisions extends previous observations into the forward region up to η=4.9. The correlation increases with growing event activity and is found to be more pronounced in the direction of the lead beam. However, the correlation in the direction of the lead and proton beams are found to be compatible when comparing events with similar absolute activity in the direction analysed.S

    Measurements of prompt charm production cross-sections in pp collisions at √s=5 TeV

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    Production cross-sections of prompt charm mesons are measured using data from pp collisions at the LHC at a centre-of-mass energy of 5 TeV. The data sample corresponds to an integrated luminosity of 8.60 ± 0.33 pb−1 collected by the LHCb experiment. The production cross-sections of D 0, D +, D +s, and D ∗+ mesons are measured in bins of charm meson transverse momentum, p T, and rapidity, y. They cover the rapidity range 2.0 < y < 4.5 and transverse momentum ranges 0 < p T < 10 GeV/c for D 0 and D + and 1 < p T < 10 GeV/c for D +s and D ∗+ mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of 1 < p T < 8 GeV/c are determined to be σ(pp→D0X)=1004±3±54μb,σ(pp→D+X)=402±2±30μb,σ(pp→D+sX)=170±4±16μb,σ(pp→D∗+X)=421±5±36μb, where the uncertainties are statistical and systematic, respectively.S

    Study of prompt D0 meson production in pPb collisions at √sNN=5 TeV

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    Production of prompt D0 mesons is studied in proton-lead and lead-proton collisions recorded at the LHCb detector at the LHC. The data sample corresponds to an integrated luminosity of 1.58±0.02 nb−1 recorded at a nucleon-nucleon centre-of-mass energy of √sNN=5 TeV. Measurements of the differential cross-section, the forward-backward production ratio and the nuclear modification factor are reported using D 0 candidates with transverse momenta less than 10 GeV/c and rapidities in the ranges 1.5 < y ∗ < 4.0 and −5.0 < y ∗ < −2.5 in the nucleon-nucleon centre-of-mass system.S

    Measurement of the B0s→J/ψη lifetime

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    Using a data set corresponding to an integrated luminosity of 3fb−1, collected by the LHCb experiment in ppcollisions at centre-of-mass energies of 7 and 8TeV, the effective lifetime in the B0s→J/ψηdecay mode, τeff, is measured to be τeff = 1.479±0.034 (stat)±0.011 (syst)ps. Assuming CPconservation, τeffcorresponds to the lifetime of the light B0smass eigenstate. This is the first measurement of the effective lifetime in this decay mode.S

    Differential branching fraction and angular moments analysis of the decay B 0 → K +π− μ + μ − in the K∗0,2(1430)0 region

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    Measurements of the differential branching fraction and angular moments of the decay B 0 → K +π− μ + μ − in the K +π− invariant mass range 1330 < m(K +π−) < 1530 MeV/c 2 are presented. Proton-proton collision data are used, corresponding to an integrated luminosity of 3 fb−1 collected by the LHCb experiment. Differential branching fraction measurements are reported in five bins of the invariant mass squared of the dimuon system, q 2, between 0.1 and 8.0 GeV2 /c 4. For the first time, an angular analysis sensitive to the S-, P- and D-wave contributions of this rare decay is performed. The set of 40 normalised angular moments describing the decay is presented for the q 2 range 1.1-6.0 GeV2 /c 4.S

    First study of the CP-violating phase and decay-width difference in B0s→ψ(2S)φ decays

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    A time-dependent angular analysis of B0s→ψ(2S)φdecays is performed using data recorded by the LHCb experiment. The data set corresponds to an integrated luminosity of 3.0 fb−1collected during Run1 of the LHC. The CP-violating phase and decay-width difference of the B0ssystem are measured to be φs=0.23+0.29−0.28±0.02 radand s=0.066+0.041−0.044±0.007 ps−1, respectively, where the first uncertainty is statistical and the second systematic. This is the first time that φsand shave been measured in a decay containing the ψ(2S)resonance.S

    Measurement of forward W → eν production in pp collisions at √s=8 TeV

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    A measurement of the cross-section for W → eν production in pp collisions is presented using data corresponding to an integrated luminosity of 2 fb−1 collected by the LHCb experiment at a centre-of-mass energy of √s=8 TeV. The electrons are required to have more than 20 GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive W production cross-sections, where the W decays to eν, are measured to be σW+→e+νe=1124.4±2.1±21.5±11.2±13.0pb, σW−→e−ν¯e=809.0±1.9±18.1±7.0±9.4pb, where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W + /W − cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of W boson branching fractions is determined to be B(W→eν)/B(W→μν)=1.020±0.002±0.019, where the first uncertainty is statistical and the second is systematic.S

    Association of Variants in the SPTLC1 Gene With Juvenile Amyotrophic Lateral Sclerosis

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    Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation.Objective: To identify the genetic variants associated with juvenile ALS.Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism.Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members.Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway.Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.</p

    Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

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    To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe
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