Keragaan Galur-galur Mutan Rumput Gajah (Pennisetum purpureum Mach) Hasil Pemuliaan In Vitro di Rumah Kaca

Rumput gajah (Pennisetum prpureum Mach) Cv Taiwan merupakan salah satu tanaman pakan ternak yang banyak dikembangkan sebagai sumber hijauan pakan ternak ruminansia besar. Induksi mutasi tanaman rumput gajah dengan sinar Gamma dapat memunculkan keragaman genetik yang berguna bagi program pemuliaan tanaman. Penelitian ini bertujuan untuk mengetahui potensi keunggulan galur-galur rumput gajah yang dihasilkan dari hasil pemuliaan in vitro menggunakan kombinasi induksi mutasi dengan iradiasi sinar Gamma dan seleksi in vitro pada populasi kalus embriogenik. Bahan tanam yang diuji dalam penelitian ini adalah 19 galur mutan rumput gajah. Percobaan dilaksanakan di rumah kaca Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian (BB BIOGEN Bogor). Variabel yang diamati adalah waktu muncul tunas, jumlah anakan, jumlah daun, tinggi tanaman, warna daun dan warna dasar batang. Rancangan yang digunakan adalah rancangan acak lengkap. Hasil penelitian menunjukkan bahwa galur-galur mutan rumput gajah hasil pemuliaan in vitro secara umum lebih baik daripada tanaman kontrol berdasarkan berdasarkan waktu muncul tunas, jumlah anakan, jumlah dan luas daun, tinggi tanaman, dan diameter batang menunjukkan keragaman yang cukup tinggi. Galur M-RG118 dan M-RG109 berpotensi untuk dikembangkan lebih lanjut karena memiliki karakter yang lebih baik dibanding tanaman asal dan galur lainnya

Potensi Ekstrak Kapang Endofit Asal Rimpang Kunyit Sebagai Antimalaria Dan Antioksidan

Malaria infection is still a public health problem, especially in developing countries, including Indonesia. Malaria infection is usually accompanied by increased free radicals in the body of the patient. This situation will cause decreasing the immune system of the patient. Explorating of new drugs that have antimalarial and also antioxidant activity is very important. Therefore, this study aims to determine in vitro antimalarial and antioxidant activity of endophytic fungi extract origin turmeric from Sukabumi. This study begins with fermentation process of endophytic fungi on the broth medium and ethyl acetate was used to extract the filtrat to gain the test extracts. Heme polymerization inhibition and free radical DPPH scavenging method were used to antimalarial and antioxidant in vitro assay respectively. The results showed that 18 isolates of endophytic fungi have antimalarial activity and one isolate inactive and also all isolates have antioxidant activity. Smi.Cl.6F isolate was the most active isolate on the antimalarial and antioxidant assay with IC50 value of each assay were 1.93 mg/mL and 32.28 mg/L respectively. Therefore, Smi.Cl.6F isolates potentially be used as new antimalarial drugs

Ehlers-Harrison transformations and black holes in Dilaton-Axion Gravity with multiple vector fields

Dilaton-axion gravity with $p U(1)$ vector fields is studied on space-times admitting a timelike Killing vector field. Three-dimensional sigma-model is derived in terms of K\"ahler geometry, and holomorphic representation of the SO(2,2+p) global symmetry is constructed. A general static black hole solution depending on $2p+5$ parameters is obtained via SO(2,2+p) covariantization of the Schwarzschild solution. The metric in the curvature coordinates looks as the variable mass Reissner-Nordstr\"om one and generically possesses two horizons. The inner horizon is pushed to the singularity if electric and magnetic SO(p) charge vectors are parallel. For non-parallel charges the inner horizon has a finite area except for an extremal limit when this property is preserved only for orthogonal charges. Extremal dyon configurations with orthogonal charges have finite horizon radii continuously varying from zero to the ADM mass. New general solution is endowed with a NUT parameter, asymptotic values of dilaton and axion, and a gauge parameter which can be used to ascribe any given value to one of scalar charges.Comment: 37 pages, Late

The Inverse Scattering Method, Lie-Backlund Transformations and Solitons for Low-energy Effective Field Equations of 5D String Theory

In the framework of the 5D low-energy effective field theory of the heterotic string with no vector fields excited, we combine two non-linear methods in order to construct a solitonic field configuration. We first apply the inverse scattering method on a trivial vacuum solution and obtain an stationary axisymmetric two-soliton configuration consisting of a massless gravitational field coupled to a non-trivial chargeless dilaton and to an axion field endowed with charge. The implementation of this method was done following a scheme previously proposed by Yurova. We also show that within this scheme, is not possible to get massive gravitational solitons at all. We then apply a non-linear Lie-Backlund matrix transformation of Ehlers type on this massless solution and get a massive rotating axisymmetric gravitational soliton coupled to axion and dilaton fields endowed with charges. We study as well some physical properties of the constructed massless and massive solitons and discuss on the effect of the generalized solution generating technique on the seed solution and its further generalizations.Comment: 17 pages in latex, changed title, improved text, added reference

Stationary BPS solutions to dilaton-axion gravity

Stationary four-dimensional BPS solutions to gravity coupled bosonic theories admitting a three-dimensional sigma-model representation on coset spaces are interpreted as null geodesics of the target manifold equipped with a certain number of harmonic maps. For asymptotically flat (or Taub-NUT) space-times such geodesics can be directly parametrized in terms of charges saturating the Bogomol'nyi-Gibbons-Hull bound, and classified according to the structure of related coset matrices. We investigate in detail the ``dilaton-axion gravity'' with one vector field, and show that in the space of BPS solutions an $SO(1,2) \times SO(2)$ classical symmetry is acting. Within the present formalism the most general multicenter (IWP/Taub-NUT dyon) solutions are derived in a simple way. We also discover a large new class of asymptotically flat solutions for which the dilaton and axion charges are constrained only by the BPS bound. The string metrics for these solutions are generically regular. Both the IWP class and the new class contain massless solutions.Comment: 29 pages, Latex, no figures. To be published in Phys. Rev. D. Minor grammatical and bibliographical change

U-Duality and Symplectic Formulation of Dilaton-Axion Gravity

We study a bosonic four--dimensional effective action corresponding to the heterotic string compactified on a 6--torus (dilaton--axion gravity with one vector field) on a curved space--time manifold possessing a time--like Killing vector field. Previously an existence of the $SO(2,3)\sim Sp(4, R)$ global symmetry ($U$--duality) as well as the symmetric space property of the corresponding $\sigma$--model have been established following Neugebauer and Kramer approach. Here we present an explicit form of the $Sp(4, R)$ generators in terms of coset variables and construct a representation of the coset in terms of the physical target space coordinates. Complex symmetric $2\times 2$ matrix $Z$ (``matrix dilaton --axion'') is introduced for which $U$--duality takes the matrix valued $SL(2, R)$ form. In terms of this matrix the theory is further presented as a K\"ahler $\sigma$--model. This leads to a more concise $2\times 2$ formulation which opens new ways to construct exact classical solutions. New solution (corresponding to constant ${\rm Im} Z$ ) is obtained which describes the system of point massless magnetic monopoles endowed with axion charges equal to minus monopole charges. In such a system mutual magnetic repulsion is exactly balanced by axion attraction so that the resulting space time is locally flat but possesses multiple Taub--NUT singularities.Comment: LATEX, 20 pages, no figure

The neuroscience of vision-based grasping: a functional review for computational modeling and bio-inspired robotics

The topic of vision-based grasping is being widely studied using various techniques and with different goals in humans and in other primates. The fundamental related findings are reviewed in this paper, with the aim of providing researchers from different fields, including intelligent robotics and neural computation, a comprehensive but accessible view on the subject. A detailed description of the principal sensorimotor processes and the brain areas involved in them is provided following a functional perspective, in order to make this survey especially useful for computational modeling and bio-inspired robotic application

Absorbing customer knowledge: how customer involvement enables service design success

Customers are a knowledge resource outside of the firm that can be utilized for new service success by involving them in the design process. However, existing research on the impact of customer involvement (CI) is inconclusive. Knowledge about customers’ needs and on how best to serve these needs (articulated in the service concept) is best obtained from customers themselves. However, codesign runs the risk of losing control of the service concept. This research argues that of the processes of external knowledge, acquisition (via CI), customer knowledge assimilation, and concept transformation form a capability that enables the firm to exploit customer knowledge in the form of a successful new service. Data from a survey of 126 new service projects show that the impact of CI on new service success is fully mediated by customer knowledge assimilation (the deep understanding of customers’ latent needs) and concept transformation (the modification of the service concept due to customer insights). However, its impact is more nuanced. CI exhibits an “∩”-shaped relationship with transformation, indicating there is a limit to the beneficial effect of CI. Its relationship with assimilation is “U” shaped, suggesting a problem with cognitive inertia where initial learnings are ignored. Customer knowledge assimilation directly impacts success, while concept transformation only helps success in the presence of resource slack. An evolving new service design is only beneficial if the firm has the flexibility to adapt to change