2,824 research outputs found

    Adolescent identity formation: Role of developmental group counseling

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    Human development is an on-going, patterned, orderly, and complex process that pertains to all humans, yet remains uniquely individual (Myrick, 1987). Human development involves a lifelong set of physiological, psychological, and social processes that begin at birth and continue until death. The personality is required to unfold, evolve and evolve again. However, it is during the period of adolescence, roughly between ages 12 and 18, that the most rigorous physiological, psychological, and social changes occur (Barrish & Barrish, 1989; Tosi, 1974)

    Purification, crystallization and X-ray diffraction analysis of human dynamin-related protein 1 GTPase-GED fusion protein

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    The mechano-enzyme dynamin-related protein 1 plays an important role in mitochondrial fission and is implicated in cell physiology. Dysregulation of Drp1 is associated with abnormal mitochondrial dynamics and neuronal damage. Drp1 shares structural and functional similarities with dynamin 1 with respect to domain organization, ability to self-assemble into spiral-like oligomers and GTP-cycle-dependent membrane scission. Structural studies of human dynamin-1 have greatly improved the understanding of this prototypical member of the dynamin superfamily. However, high-resolution structural information for full-length human Drp1 covering the GTPase domain, the middle domain and the GTPase effector domain (GED) is still lacking. In order to obtain mechanistic insights into the catalytic activity, a nucleotide-free GTPase-GED fusion protein of human Drp1 was expressed, purified and crystallized. Initial X-ray diffraction experiments yielded data to 2.67 angstrom resolution. The hexagonal-shaped crystals belonged to space group P2(1)2(1)2, with unit-cell parameters a = 53.59, b = 151.65, c = 43.53 angstrom, one molecule per asymmetric unit and a solvent content of 42%. Expression of selenomethionine-labelled protein is currently in progress. Here, the expression, purification, crystallization and X-ray diffraction analysis of the Drp1 GTPase-GED fusion protein are presented, which form a basis for more detailed structural and biophysical analysis

    Comparison of skin microvascular reactivity with hemostatic markers of endothelial dysfunction and damage in type 2 diabetes

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    AIM: Patients with non-insulin-dependent diabetes mellitus (NIDDM) are at increased cardiovascular risk due to an accelerated atherosclerotic process. The present study aimed to compare skin microvascular function, pulse wave velocity (PWV), and a variety of hemostatic markers of endothelium injury [von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA), tissue factor pathway inhibitor (TFPI), and the soluble form of thrombomodulin (s-TM)] in patients with NIDDM. METHODS: 54 patients with NIDDM and 38 sex- and age-matched controls were studied. 27 diabetics had no overt micro- and/or macrovascular complications, while the remainder had either or both. The forearm skin blood flow was assessed by laser-Doppler imaging, which allowed the measurement of the response to iontophoretically applied acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation), as well as the reactive hyperemia triggered by the transient occlusion of the circulation. RESULTS: Both endothelial and non-endothelial reactivity were significantly blunted in diabetics, regardless of the presence or the absence of vascular complications. Plasma vWF, TFPI and s-TM levels were significantly increased compared with controls only in patients exhibiting vascular complications. Concentrations of t-PA and PAI-1 were significantly increased in the two groups of diabetics versus controls. CONCLUSION: In NIDDM, both endothelium-dependent and -independent microvascular skin reactivity are impaired, whether or not underlying vascular complications exist. It also appears that microvascular endothelial dysfunction is not necessarily associated in NIDDM with increased circulating levels of hemostatic markers of endothelial damage known to reflect a hypercoagulable state

    Impact of plant protection strategy and soil tillage on the carbon footprint of wheat

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    Der Klimaschutz liegt aufgrund der zunehmenden negativen Auswirkungen des Klimawandels auf die pflanz­liche Produktion im Eigeninteresse der Landwirtschaft. Welche Auswirkungen unterschiedliche Pflanzenschutzstrategien, der Verzicht auf Fungizide sowie eine reduzierte Bodenbearbeitung auf die Klimawirkung der Weizenproduktion haben wurde aufbauend auf einem Dauerfeldversuch in Dahnsdorf in 2008–2019 untersucht. Die Bewertung wurden mittels partieller Lebenszyklus (LCA) durchgeführt. Im Durchschnitt über sämtliche Versuchsvarianten und Jahre lagen die Treibhausgasemissionen (THG-Emissionen) bei 3002 kg CO2eq ha‑1 und der CO2-Fußabdruck (CFP) bei 0,53 kg CO2eq kg‑1. Obwohl die Varianten mit wendender Bodenbearbeitung signifikant höhere THG-Emissionen je ha aufwiesen, waren Ihre CFPs nicht signifikant höher als die der nicht-wendenden Varianten. Die ertragssichernde Wirkung der Fungizide führte zu verringerten CFPs. Signifikante Jahresunterschiede zeigten sich bei allen drei untersuchten Parametern. Dies unterstreicht die Notwendigkeit einer Bewertung über längere Zeitreihen und den besonderen Wert von Langzeitversuchen.Climate protection is in the self-interest of agriculture due to the increasing negative effects of climate change on crop production. The effects of different crop protection strategies, the non-usage of fungicides, and reduced tillage were assessed regarding climate impact of wheat production based on a long-term field trial in Dahnsdorf in 2008–2019. The assessment was carried out using a partial life cycle assessment (LCA). On average across all treatments and years, greenhouse gas (GHG) emissions were 3002 kg CO2eq ha-1 and carbon footprint (CFP) was 0.53 kg CO2eq kg-1. Although the treatments with plow caused significantly higher GHG emissions per hectare, their CFPs were not significantly higher than those of the non-plowed treatments. The yield-securing effects of fungicides led to reduced CFPs. Significant differences between years were evident for all three parameters examined. This underlines the need for an evaluation over longer time series and the special value of long-term field trials

    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

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

    Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

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    The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic
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