Quaternionic (super)twistors extensions and general superspaces

In a attempt to treat a supergravity as a tensor representation, the 4-dimensional N-extended quaternionic superspaces are constructed from the (diffeomorphyc)graded extension of the ordinary Penrose-twistor formulation, performed in a previous work of the authors[14], with N = p + k: These quaternionic superspaces have 4 + k (N - k) even-quaternionic coordinates and 4N odd- quaternionic coordinates where each coordinate is a quaternion composed by four C-felds (bosons and fermions respectively). The fields content as the dimensionality (even and odd sectors) of these superspaces are given and exemplified by selected physical cases. In this case the number of felds of the supergravity is determined by the number of components of the tensor representation of the 4-dimensional N-extended quaternionic superspaces. The role of tensorial central charges for any N even USp (N) = Sp (N;HC) \ U (N;HC) is elucidated from this theoretical context.Comment: To be published in the IJGMMP 2016, corrected version, 16 pages without figure

Quaternionic structures, supertwistors and fundamental superspaces

Superspace is considered as space of parameters of the supercoherent states defining the basis for oscillator-like unitary irreducible representations of the generalized superconformal group SU(2m,2n/2N) in the field of quaternions H. The specific construction contains naturally the supertwistor one of the previous work by Litov and Pervushin [1] and it is shown that in the case of extended supersymmetry such an approach leads to the separation of a class of superspaces and and its groups of motion. We briefly discuss this particular extension to the domain of quaternionic superspaces as nonlinear realization of some kind of the affine and the superconformal groups with the final end to include also the gravitational field[6] (this last possibility to include gravitation, can be realized on the basis of the reference[12] where the coset ((Sp(8))/(SL(4R)))~((SU(2,2))/(SL(2C)))was used in the non supersymmetric case). It is shown that this quaternionic construction avoid some unconsistencies appearing at the level of the generators of the superalgebras (for specific values of p and q; p+q=N) in the twistor one.Comment: Improved version. Accepted in the International Journal of Geometrical Methods in Modern Physics (IJGMMP)12 pages, no figures. In memoriam of Professor Boris Moyseevich Zupnik, pioneer of the development of supersymmetry, group theory and modern mathematical methods in theoretical physic

Intertemporal Substitution in Macroeconomics

Modern neoclassical theories of the business cycle posit that aggregate fluctuations in consumption and employment are the consequence of dynamic optimizing behavior by economic agents who face no quantity constraint. In this paper, we estimate an explicit model :f this type. In particular, we assume that the observed fluctuations correspond to the decisions of an optimizing representative individual. This individual has a stable utility function which is additively separable over time but not necessarily additively separable in consumption and leisure. We estimate three first order conditions which represent three margins on which the individual is optimizing. He can trade off present consumption for future consumption, present leisure for future leisure and present consumption for present leisure. Our results show that the aggregate U.S. data are extremely reluctant to be characterized by a model of this type. Not only are the overidentifying restrictions statistically rejected but, in addition, the estimated utility function is often not concave. Even when it is concave the estimates imply that either consumption or leisure is an inferior good.

Tailored particle current in an optical lattice by a weak time-symmetric harmonic potential

Quantum ratchets exhibit asymptotic currents when driven by a time-periodic potential of zero mean if the proper spatio-temporal symmetries are broken. There has been recent debate on whether directed currents may arise for potentials which do not break these symmetries. We show here that, in the presence of degeneracies in the quasienergy spectrum, long-lasting directed currents can be induced, even if the time reversal symmetry is not broken. Our model can be realized with ultracold atoms in optical lattices in the tight-binding regime, and we show that the time scale of the average current can be controlled by extremely weak fields.Comment: 4 pages, 4 figure

Effective non-additive pair potential for lock-and-key interacting particles: the role of the limited valence

Theoretical studies of self-assembly processes and condensed phases in colloidal systems are often based on effective inter-particle potentials. Here we show that developing an effective potential for particles interacting with a limited number of ``lock-and-key'' selective bonds (due to the specificity of bio-molecular interactions) requires -- beside the non-sphericity of the potential -- a (many body) constraint that prevent multiple bonding on the same site. We show the importance of retaining both valence and bond-selectivity by developing, as a case study, a simple effective potential describing the interaction between colloidal particles coated by four single-strand DNA chains.Comment: 4 pages, 5 figure

Kajian Perubahan Garis Pantai Menggunakan Citra Landsat Multitemporal di Kota Semarang

Kota Semarang merupakan ibu kota Provinsi Jawa Tengah. Pembangunan Kota Semarang sangat berkembang sehingga kebutuhan lahan mendorong kegiatan reklamasi. Pengaruh kegiatan reklamasi berdampak terhadap dinamika garis pantai pesisir Kota Semarang. Tujuan penelitiannya mengidentifikasi Perubahan garis pantai menggunakan Landsat TM tahun 1994,2004 dan 2014. Metode penelitiannya adalah interpretasi citra, survey lapangan. Hasil analisis Perubahan garis pantai dilakukan Overlay, serta single transect menghasilkan panjang rata-rata Perubahan garis pantai. Overlay peta tentatif 1994-2004 dan 2004-2014 akan menghasilkan peta Perubahan garis pantai selama 10tahunan. Hasil penelitian menunjukan reklamasi seluas 35,9hektar di tahun 1994-2004 dan 241,9ha di tahun 2004-2014; serta abrasi 108,78ha tahun 1994-2004 dan 73,7hektar di tahun 2004-2014. Proses sedimentasi sangat kecil dengan luas 19,34ha di tahun 1994-2004 dan 2,14ha di tahun 2004-2014. Kawasan yang mengalami reklamasi di Kecamatan Semarang Barat, Semarang Utara serta sebagian Tugu bagian barat. Sementara abrasi pantai terjadi di kawasan pesisir Genuk, Semarang Utara sebelah barat, dan sebagian Tugu. Faktor hidrooseanografi, penurunan tanah dan reklamasi cukup berpengaruh dalam dinamika Perubahan garis pantai pesisir Kota Semarang

Volatile compound diversity and conserved alarm behaviour in Triatoma dimidiata

Background: Triatoma dimidiata (Latreille) is a key vector complex of Trypanosoma cruzi, etiologic agent of Chagas disease, as it spans North, Central, and South America. Although morphological and genetic studies clearly indicate existence of at least five clades within the species, there has been no robust or systematic revision, or appropriate nomenclature change for species within the complex. Three of the clades (haplogroups) are distributed in Mexico, and recent evidence attests to dispersal of clades across previously "presumed"monotypic geographic regions. Evidence of niche conservatism among sister species of this complex suggests that geographic dispersal is possible for non-sympatric populations, although no information is available on the behavioural aspects of potential interclade interactions, for instance whether differentiation of chemical signaling or response to these signals could impede communication among the haplogroups. Methods: Volatiles emitted by disturbed bugs, Brindley's (BGs), and metasternal (MGs) glands were identified using solid-phase micro-extraction (SPME) and gas chromatography coupled mass spectrometry (GC-MS). Volatile compounds emitted by BGs and MGs, and those secreted by disturbed nymphs and adults, of the three Mexican T. dimidiata haplogroups were tested for avoidance behaviour by conspecific nymphs and adults using an olfactometer. Results: Triatoma dimidiata haplogroups all have three age-related alarm responses: absence of response by early stage nymphs, stage-specific response by 4-5th stage nymphs, and a shared 4-5th nymph and adult response to adult compounds. Disturbed bugs released 15 to 24 compounds depending on the haplogroup, among which were three pyrazines, the first report of these organoleptics in Triatominae. Isobutyric acid from BGs was the most abundant molecule in the response in all haplogroups, in addition to 15 (h1) to 21 (h2 and h3) MG compounds. Avoidance behaviour of disturbed bugs and volatiles emitted by BGs were haplogroup specific, while those from the MG were not. Conclusions: Discriminant and cluster analysis of BG +MG compounds indicate significant separation among the three haplogroups, while alarm response compounds were similar between h2 and h3, both distinct from h1. This latter haplogroup is ancestral phylogenetically to the other two. Our results suggest that alarm responses are a conserved behaviour in the Triatoma dimidiata complex.Fil: May Concha, Irving Jesus. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Instituto Nacional de Salud Pública; MéxicoFil: Rojas, Julio C.. El Colegio de la Frontera Sur; MéxicoFil: Cruz López, Leopoldo. El Colegio de la Frontera Sur; MéxicoFil: Ibarra-Cerdeña, Carlos N.. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados; MéxicoFil: Ramsey, Janine. Instituto Nacional de Salud Pública; Méxic