Pengaruh Cekaman Air Dan Kombinasi Pupuk Nitrogen Dan Kalium Terhadap Pertumbuhan Dan Kadar Minyak Atsiri Tanaman Serai Wangi (Cymbopogon Nardus L.)

Serai wangi (Cymbopogon nardus L.) merupakan tanaman penghasil minyak atsiri dari kelompok Graminiae. Tujuan penelitian ini adalah mendapatkan peningkatan hasil tanaman serai wangi secara kuantitas maupun kualitas dengan pemberian air pada kadar tertentu dan pemberian kombinasi pupuk Nitrogen dan Kalium pada kombinasi tertentu. Penelitian menggunakan Rancangan Acak Kelompok, dengan 8 perlakuan yaitu kombinasi dari perlakuan air (100% dan 50% kapasitas lapang) dan perlakuan kombinasi pupuk Urea (46% N) (0, 2, 4, 6 g polybag-) dan KCl (60% K2O) (0, 1,5, 3,5, 5 g polybag-), dengan 4 kali ulangan. Penelitian dilakukan di desa Kepuharjo, Kabupaten Malang. Penelitian dilaksanakan bulan April hingga Juli 2014. Hasil penelitian menunjukan tidak ada pengaruh nyata perlakuan terhadap parameter pertumbuhan dan perlakuan air 50% dari kapasitas lapang memberikan pengaruh nyata dengan peningkatan kadar atsiri yaitu: P5: 1,002%, P6: 1,014%, P7: 1,102%, dan P8: 1,064% sedangkan pemberian air pada kapasitas lapang yaitu P1: 0,872%, P2: 0,660%, P3: 0,798%, dan P4: 0,904%. Perlakuan pemberian air pada 50% kapasitas lapang dan pemberian pupuk Urea (46% N) 4 g polybag- dan KCl (60% K2O) 3,5 g polybag- memberikan hasil kadar atsiri tertinggi pada tanaman serai wangi yaitu 1,102%

Time evolution of dynamic propensity in a model glass former. The interplay between structure and dynamics

By means of the isoconfigurational method we calculate the change in the propensity for motion that the structure of a glass-forming system experiences during its relaxation dynamics. The relaxation of such a system has been demonstrated to evolve by means of rapid crossings between metabasins of its potential energy surface (a metabasin being a group of mutually similar, closely related structures which differ markedly from other metabasins), as collectively relaxing units (d-clusters) take place. We now show that the spatial distribution of propensity in the system does not change significantly until one of these d-clusters takes place. However, the occurrence of a d-cluster clearly de-correlates the propensity of the particles, thus ending up with the dynamical influence of the structural features proper of the local metabasin. We also show an important match between particles that participate in d-clusters and that which show high changes in their propensity.Comment: 7 pages, 8 figures, articl

Career coach preferences of medical students: coaching specialist or specialistic coach?

Background: Medical students’ demand for career coaching is growing. However, little is known about what type of career coach they prefer. Using the Warmth-Competence Framework, we investigated if and why medical students prefer physician coaches compared to career psychologist coaches. We also examined whether students’ coach choice related to coaches’ amount of experience with medical students. Methods: In a two-by-two between participants vignette study (n = 147), we manipulated coach occupational background (physician vs. psychologist) and experience with coaching medical students (limited vs. considerable). Participants read one coach description, rated the likelihood that they would choose the coach, and rated the coach on dimensions of warmth and competence. Results: Students who evaluated a physician career coach were more likely to choose the coach than students who evaluated a psychologist career coach. Students expected that a physician career coach would better understand their situation and be better able to provide career information, while they expected a psychologist career coach to have better conversation skills, all of which were relevant to choosing a coach. Coaches’ experience with coaching medical students was unrelated to students’ coach choice and their assessment of the coach’s warmth and competence. Conclusions: Our findings highlight the relevance of coaches’ occupational background and have implications for the implementation of career coach interventions. Medical schools could help students choose a career coach by providing information about the coach qualities that students value. Future studies could investigate whether career coaches with different occupational backgrounds differ in coach behaviors and coaching effectiveness.</p

Defining Meyer's loop-temporal lobe resections, visual field deficits and diffusion tensor tractography

Anterior temporal lobe resection is often complicated by superior quadrantic visual field deficits (VFDs). In some cases this can be severe enough to prohibit driving, even if a patient is free of seizures. These deficits are caused by damage to Meyer's loop of the optic radiation, which shows considerable heterogeneity in its anterior extent. This structure cannot be distinguished using clinical magnetic resonance imaging sequences. Diffusion tensor tractography is an advanced magnetic resonance imaging technique that enables the parcellation of white matter. Using seed voxels antero-lateral to the lateral geniculate nucleus, we applied this technique to 20 control subjects, and 21 postoperative patients. All patients had visual fields assessed with Goldmann perimetry at least three months after surgery. We measured the distance from the tip of Meyer's loop to the temporal pole and horn in all subjects. In addition, we measured the size of temporal lobe resection using postoperative T1-weighted images, and quantified VFDs. Nine patients suffered VFDs ranging from 22% to 87% of the contralateral superior quadrant. In patients, the range of distance from the tip of Meyer's loop to the temporal pole was 24–43 mm (mean 34 mm), and the range of distance from the tip of Meyer's loop to the temporal horn was –15 to +9 mm (mean 0 mm). In controls the range of distance from the tip of Meyer's loop to the temporal pole was 24–47 mm (mean 35 mm), and the range of distance from the tip of Meyer's loop to the temporal horn was –11 to +9 mm (mean 0 mm). Both quantitative and qualitative results were in accord with recent dissections of cadaveric brains, and analysis of postoperative VFDs and resection volumes. By applying a linear regression analysis we showed that both distance from the tip of Meyer's loop to the temporal pole and the size of resection were significant predictors of the postoperative VFDs. We conclude that there is considerable variation in the anterior extent of Meyer's loop. In view of this, diffusion tensor tractography of the optic radiation is a potentially useful method to assess an individual patient's risk of postoperative VFDs following anterior temporal lobe resection

Superintegrability on N-dimensional spaces of constant curvature from so(N+1) and its contractions

The Lie-Poisson algebra so(N+1) and some of its contractions are used to construct a family of superintegrable Hamiltonians on the ND spherical, Euclidean, hyperbolic, Minkowskian and (anti-)de Sitter spaces. We firstly present a Hamiltonian which is a superposition of an arbitrary central potential with N arbitrary centrifugal terms. Such a system is quasi-maximally superintegrable since this is endowed with 2N-3 functionally independent constants of the motion (plus the Hamiltonian). Secondly, we identify two maximally superintegrable Hamiltonians by choosing a specific central potential and finding at the same time the remaining integral. The former is the generalization of the Smorodinsky-Winternitz system to the above six spaces, while the latter is a generalization of the Kepler-Coulomb potential, for which the Laplace-Runge-Lenz N-vector is also given. All the systems and constants of the motion are explicitly expressed in a unified form in terms of ambient and polar coordinates as they are parametrized by two contraction parameters (curvature and signature of the metric).Comment: 14 pages. Based on the contribution presented at the "XII International Conference on Symmetry Methods in Physics", Yerevan (Armenia), July 2006. To appear in Physics of Atomic Nucle

Path Integral Approach for Superintegrable Potentials on Spaces of Non-constant Curvature: II. Darboux Spaces DIII and DIV

This is the second paper on the path integral approach of superintegrable systems on Darboux spaces, spaces of non-constant curvature. We analyze in the spaces \DIII and \DIV five respectively four superintegrable potentials, which were first given by Kalnins et al. We are able to evaluate the path integral in most of the separating coordinate systems, leading to expressions for the Green functions, the discrete and continuous wave-functions, and the discrete energy-spectra. In some cases, however, the discrete spectrum cannot be stated explicitly, because it is determined by a higher order polynomial equation. We show that also the free motion in Darboux space of type III can contain bound states, provided the boundary conditions are appropriate. We state the energy spectrum and the wave-functions, respectively

Superintegrability on sl(2)-coalgebra spaces

We review a recently introduced set of N-dimensional quasi-maximally superintegrable Hamiltonian systems describing geodesic motions, that can be used to generate "dynamically" a large family of curved spaces. From an algebraic viewpoint, such spaces are obtained through kinetic energy Hamiltonians defined on either the sl(2) Poisson coalgebra or a quantum deformation of it. Certain potentials on these spaces and endowed with the same underlying coalgebra symmetry have been also introduced in such a way that the superintegrability properties of the full system are preserved. Several new N=2 examples of this construction are explicitly given, and specific Hamiltonians leading to spaces of non-constant curvature are emphasized.Comment: 12 pages. Based on the contribution presented at the "XII International Conference on Symmetry Methods in Physics", Yerevan (Armenia), July 2006. To appear in Physics of Atomic Nucle

Deformed oscillator algebras for two dimensional quantum superintegrable systems

Quantum superintegrable systems in two dimensions are obtained from their classical counterparts, the quantum integrals of motion being obtained from the corresponding classical integrals by a symmetrization procedure. For each quantum superintegrable systema deformed oscillator algebra, characterized by a structure function specific for each system, is constructed, the generators of the algebra being functions of the quantum integrals of motion. The energy eigenvalues corresponding to a state with finite dimensional degeneracy can then be obtained in an economical way from solving a system of two equations satisfied by the structure function, the results being in agreement to the ones obtained from the solution of the relevant Schrodinger equation. The method shows how quantum algebraic techniques can simplify the study of quantum superintegrable systems, especially in two dimensions.Comment: 22 pages, THES-TP 10/93, hep-the/yymmnn