SLOW AND STEADY WINS THE ORGANIC RACE

Organic production is carried out under an extensive regulatory setup because organic products are sold as value-added products with certified organic labelling in developed countries. Production is strictly monitored at every step in production chain. Organic production apart from being eco-friendly offers higher net returns per unit area compared to conventional agriculture. Organic production uses traditional tillage systems, crop rotations, crop residues, animal manures, legumes, green manures, off-farm organic wastes, mineral bearing rocks, and biological pest and weed control to maintain soil productivity. Thus, an organic farm should be a self contained system of production with minimal dependence on external inputs. Those farms having dairy as one of the active components will have to convert to organic livestock management so that manures supplied are as per requirements for organic production. The dairy products can also be certified organic to fetch higher prices. Organic farming is a highly labour intensive enterprise. Some of the major organic accreditation agencies are IFOAM (International Federation of Organic Agriculture Movements), FiBL, Demeter and many more. APEDA has also developed national standards for organic production. Indian farmers face many challenges in adoption of certified organic production. Some of the important organic production requirements as per national standards for organic production have been developed by APEDA.Genetically engineered cultivars or plant materials are not permitted in organic production. Some of the important organic production requirements as per national standards for organic production have been developed by APEDA. Some of the important organic production requirements as per national standards for organic production have been developed by APEDA.Before products from a farm/project can be certified as organic, inspection shall be carried out during the conversion period. To ensure a clear separation between organic and conventional production, the certification programme (agency) shall inspect, where appropriate, the whole production system. Organic production is one area of agriculture which can convert India’s ‘Green Revolution’ into ‘Evergreen Revolution’

Spatiotemporal evolution of non-diffracting plasmonic pulses

Beugung ist ein allgegenwärtiges Phänomen in der Optik. In den späten 80er Jahren wurden zur Auslösung der Beugung Bessel-Strahlen vorgeschlagen und beobachtet. Bessel-Strahlen breiten sich im freien Raum ohne Beugung aus, sie können jedoch nur in drei Dimensionen existieren. Im letzten Jahrzehnt hat sich nach der bahnbrechenden Arbeit von Siviloglou und Christodoulides über Airy-Strahlen erhebliches Interesse an nicht-beugenden Strahlen entwickelt. Da die Airy-Strahlen auch in zwei Dimensionen existieren können, eignen sie sich besonders für die planarephotonik, z. B. an Metall-Dielektrikum-Grenzflächen. In dieser Doktorarbeit wird die Erzeugung von Airy-Strahlen und deren Eigenschaften an der Metall-Dielektrikum-Grenzfläche eingehend untersucht. Der Kern dieser Arbeit untersucht die räumliche und raum- zeitliche Entwicklung von Airy-Plasmonen. Ausreichendes Hintergrundwissen über elektromagnetische Theorie und numerische Methoden wurde dafür benötigt. Wir haben die räumlichen Eigenschaften von Airy-Plasmonen mit Hilfe der Photoemissions- Elektronenmikroskopie untersucht und eine rigorose Finite-Di erenzen-Zeitbereichsm- ethode angewendet. Die Ergebnisse wurden auch durch die Verwendung einer Strahl- propagationsmethode (BPM) bestätigt. Die BPM bietet eine Simulationsmethode zur schnelleren Optimierung der Struktur des anregungsgitters der Airy-Plasmonen. Diese Arbeit quantifiziert weiter die Erzeugungse zienz der nichtparaxialen Airy-Plasmonen eines Beugungsgitters. Es wurde eine breitbandige Erzeugungsbandbreite von Airy- Plasmonen gefunden, was einen gangbaren Weg zur Untersuchung von ultrakurz ge- pulsten Airy-Plasmonen darstellt. Das Beugungsgitter wurde optimiert, um die ultra- kurzen Airy-Plasmonenpulse zu erzeugen. Die raumzeitliche Entwicklung von Airy- Plasmonenpulsen wurde numerisch untersucht. Ein analytisches, semi-analytisches und numerisches Modell wurden eingesetzt, um die Trajektorie der zeitgemittelten Airy-Plasmonenpulse zu untersuchen

Exact universal bounds on quantum dynamics and fast scrambling

Quantum speed limits such as the Mandelstam-Tamm or Margolus-Levitin bounds offer a quantitative formulation of the energy-time uncertainty principle that constrains dynamics over short times. We show that the spectral form factor, a central quantity in quantum chaos, sets a tighter universal bound on the quantum dynamics of a complete set of initial states over arbitrarily long times. This bound further generalizes naturally to the real-time dynamics of time-dependent or dissipative systems where no energy spectrum exists. We use this result to constrain the scrambling of information in interacting many-body systems. For Hamiltonian systems, we show that the fundamental question of the fastest possible scrambling time -- without any restrictions on the structure of interactions -- maps to a purely mathematical property of the density of states involving the non-negativity of Fourier transforms.Comment: 4.5 pages + references; 4-page supplemen

Dynamical quantum ergodicity from energy level statistics

Ergodic theory provides a rigorous mathematical description of classical dynamical systems including a formal definition of the ergodic hierarchy. Closely related to this hierarchy is a less-known notion of cyclic approximate periodic transformations [see, e.g., I. Cornfield, S. Fomin, and Y. Sinai, Ergodic theory (Springer-Verlag New York, 1982)], which maps any "ergodic" dynamical system to a cyclic permutation on a circle and arguably represents the most elementary notion of ergodicity. This paper shows that cyclic ergodicity generalizes to quantum dynamical systems, and this generalization is proposed here as the basic rigorous definition of quantum ergodicity. It implies the ability to construct an orthonormal basis, where quantum dynamics transports an initial basis vector to all other basis vectors one by one, while maintaining a sufficiently large overlap between the time-evolved initial state and a given basis state. It is proven that the basis, maximizing the overlap over all cyclic permutations, is obtained via the discrete Fourier transform of the energy eigenstates. This relates quantum cyclic ergodicity to level statistics. We then show that the near-universal Wigner-Dyson level statistics implies quantum cyclic ergodicity, but the reverse is not necessarily true. For the latter, we study irrational flows on a 2D torus and prove that both the classical and quantum flows are cyclic ergodic. However, the corresponding level statistics is neither Wigner-Dyson nor Poisson. Finally, we use the cyclic construction to motivate a quantum ergodic hierarchy of operators and argue that under the additional assumption of Poincare recurrences, cyclic ergodicity is a necessary condition for such operators to satisfy the eigenstate thermalization hypothesis. This work provides a general framework for transplanting some rigorous concepts of ergodic theory to quantum dynamical systems.Comment: 42+11 pages, 9+1 figures; v2: updated definition of aperiodicity, analytical results for tori, improved presentation and some new figure

Implications of an updated ultraviolet background for the ionization mechanisms of intervening Ne VIII absorbers

Ne VIII absorbers seen in QSO spectra are useful tracers of warm ionized gas, when collisional ionization is the dominant ionization process. While photoionization by the ultraviolet background (UVB) is a viable option, it tends to predict large line-of-sight thickness for the absorbing gas. Here, we study the implications of the recently updated UVB at low-z to understand the ionization mechanisms of intervening Ne VIII absorbers. With the updated UVB, one typically needs higher density and metallicity to reproduce the observed ionic column densities under photoionization. Both reduce the inferred line-of-sight thicknesses of the absorbers. We find a critical density of $\geq5\times10^{-5}$ cm$^{-3}$ above which the observed N(Ne VIII)/N(O VI) can be reproduced by pure collisional processes. If the gas is of near solar metallicity (as measured for the low ions) then the cooling timescales will be small (<$10^{8}$ yrs). Therefore, a continuous injection of heat is required in order to enhance the detectability of the collisionally ionized gas. Using photoionization models we find that in almost all Ne VIII systems the inferred low ion metallicity is near solar or supersolar. If we assume the Ne VIII phase to have similar metallicities then photoionization can reproduce the observed N(Ne VIII)/N(O VI) without the line-of-sight thickness being unreasonably large and avoids cooling issues related to the collisional ionization at these metallicities. However the indication of broad Ly$\alpha$ absorption in a couple of systems, if true, suggests that the Ne VIII phase is distinct from the low ion phase having much lower metallicity.Comment: 11 pages, 5 figures, 2 tables. Accepted for publication in MNRA

An epidemiological survey to assess the clinical use of cephalosporins in community-acquired respiratory tract infections

Background: In outpatient management of respiratory tract infections, the clinicians’ preferences always have  a broad spectrum of antibiotics as an empirical therapy. Clinical use of cephalosporins and fluoroquinolones has been recommended by various international guidelines as a monotherapy or as combination therapy to manage these. This survey was conducted to assess the in-clinic use and preference of cephalosporins or fluoroquinolones as monotherapy or as combination therapy in managing respiratory tract infections by Indian doctors.Methods: A survey questionnaire was drafted to capture the feedback from cross-specialty regarding the preference of using antibiotics in respiratory tract infection in real time clinical settings.Results: Data from 163 physicians were collected and evaluated across India. 79 (48%) clinicians reported pharyngitis/tonsillitis to be the most commonly encountered respiratory tract infection followed by community-acquired pneumonia (CAP) 62 (38%). 100 (61%) clinicians preferred use of cefpodoxime monotherapy as a primary line of treatment for the management of respiratory pharyngitis/tonsillitis. Use of short course therapy (≤1 week) of cefpodoxime and levofloxacin as combination therapy is preferred by 94 (58%) clinicians, in cases of acute exacerbation of chronic bronchitis (AECB) 85 (52%), and CAP 83 (51%). The clinical preference of levofloxacin was observed with only 16 (10%) clinicians, in lower respiratory tract infections, i.e. AECB and CAP.Conclusion: In-clinic use of cefpodoxime as monotherapy is preferred in upper respiratory tract infections. However, clinicians recommend a combination therapy of cefpodoxime and levofloxacin in lower respiratory tract infections