Gauge Coupling Unification in E6 F-Theory GUTs with Matter and Bulk Exotics from Flux Breaking

We consider gauge coupling unification in E6 F-Theory Grand Unified Theories (GUTs) where E6 is broken to the Standard Model (SM) gauge group using fluxes. In such models there are two types of exotics that can affect gauge coupling unification, namely matter exotics from the matter curves in the 27 dimensional representation of E6 and the bulk exotics from the adjoint 78 dimensional representation of E6. We explore the conditions required for either the complete or partial removal of bulk exotics from the low energy spectrum. In the latter case we shall show that (miraculously) gauge coupling unification may be possible even if there are bulk exotics at the TeV scale. Indeed in some cases it is necessary for bulk exotics to survive to the TeV scale in order to cancel the effects coming from other TeV scale matter exotics which would by themselves spoil gauge coupling unification. The combination of matter and bulk exotics in these cases can lead to precise gauge coupling unification which would not be possible with either type of exotics considered by themselves. The combination of matter and bulk exotics at the TeV scale represents a unique and striking signature of E6 F-theory GUTs that can be tested at the LHC.Comment: 21 pages, 5 figure

Seasonal Shoot-Feeding by \u3ci\u3eTomicus Piniperda\u3c/i\u3e (Coleoptera: Scolytidae) in Michigan

Seasonal shoot-feeding by Tomicus piniperda (L.) was monitored at 2­ week intervals on 15 Scotch pine, Pinus sylvestris L., trees from 8 April through 16 November 1994 in southern Michigan. All shoots that showed evidence of T. piniperda attack were removed every two weeks. In 1994, initial spring flight of T. piniperda began on 22 March. At least two live T. piniperda adults were found on the 15 trees on each sampling date from 8 April through 1 November 1994. In addition, at least one freshly attacked, beetle- free shoot was found on each sampling date except for 1 November. The greatest numbers of newly attacked shoots, with or without adults present, were found from mid-June through mid-August. All adults found in April and May were likely parent adults, while those from June onward were primarily brood adults. Therefore, at all times of the year, live T. piniperda adults can be found on live pine trees, either feeding in the shoots or overwintering at the base of the trunk. Implications of these findings are provided in light of the US federal quarantine on T. piniperda

X-ray spectrum of the high polarization quasar PKS 1510-089

We present results on the X-ray spectra of the radio-loud, high-polarization quasar, PKS 1510-089, based on new data obtained using ASCA, and from archival ROSAT data. The X-ray spectrum obtained by ASCA is unusually hard, with the photon index=1.30+-0.06, while the (non-simultaneous) ROSAT data indicate a steeper spectrum (1.9+-0.3). The X-ray flux at 1 keV is within 10% during both observations. A break in the underlying continuum at about 0.7 keV is suggested. Flat X-ray spectra seem to be the characteristic of high polarization quasars, and their spectra also appear to be harder than that of the other radio-loud but low-polarization quasars. The multiwavelength spectrum of PKS 1510-089 is similar to many other gamma-ray blazars, suggesting the emission is dominated by that from a relativistic jet. A big blue-bump is also seen in its multiwavelength spectrum, suggesting the presence of a strong thermal component as well.Comment: 19 pages (Latex + 5 ps figures), Accpeted for publication in the Astrophysical Journal, December 20, 199

IRAS observations of AGN candidates at low flux levels

IRAS additional observations were used to obtain a sample of point sources at much fainter flux levels than hitherto available through the IRAS Point Source Catalogue. This sample is being used to compile an incomplete but representative catalogue of faint IRAS candidate Active Galactic Nuclei (AGNs) and to study the evolution of the infrared bright galaxies. Ground based follow up observations (optical spectroscopy) are mainly hampered by identification confusion

Identification of eggs and larvae

History of identification of fish eggs and larvae; Towards the end of the 19th century Marine Biologists, Holt and Scott (1898) Mintosh and Masterman (1897)., Cunningham (1897) and E hrenbaum (1905-1909) succeeded in describing the eggs and larvae of a large number of marine teleostean fishes in European waters. The Danish scientists, Schmidt (1904-1918) and Petersen (1892-1919) described several postlarval stages of demersal fishes, These efforts were supplemented by Claric (1920), Ford (1920-1931) and Lebour (1919-1927) at Plymouth. The prolific contributions of Japanese workers as well as those from USSR and Germany have not been freely accessible to Indian workers either due to language problems or for other reasons

Diseases and their control in aquaculture system

The importance of aquaculture to the population of India is well known. There is considerable scope for improving the fish protein resources by resorting to intensive and scientific methods of aquaculture. Aquaculture helps to augment production and provides gainful employment to people. In this system, fish is stocked in culture farms at a high density and given artificial feeds. Unnaturally high population favours the spread of diseases. Disease is one of the most serious problems in aquaculture. The frequency and severity of disease outbreaks have increased with the intensification of aquaculture

Histological examination of tissues of experimental fish

Nutrition and pathology are related disciplines. Gounelle (1961) observed that "Every disease has a nutritional aspect. Pathology is concerned with specific disease process and resultant tissue changes in the individual what ever its systemic position. The study of disease process involves at a greater extent the histological examination of various organs and tissues. The histological examination of tissue in a nutritional experiment provide an opportunity to observe the resultant changes occurring at cellular level. Many times a particular treatment may not produce any physiological or reproductive effect immediately; however histological examination may reveal considerable changes. It is also important before advocating any feed or a combination of feed for field use we have to ascertain whether the said combination contain any type of toxic factor This can be settled only by conducting an experiment in which histopathological examination forms the major component

Postlarva of the Seerfish Scomberomorus commerson (Lacepede) (Scombridae, Pisces) from the South West Coast of India

Larval and postlarval stages of Scomberomorus are rarely recorded from Indian waters. One postlarva of S. commerson 10.7 mm in total length was obtained in an oblique tow from 55 m upwards with a Bongo net at a station 60 m depth off Cochin in December 1975, fromR.V. Rastrelliger, The specimen is described and illustrated. Compared to postlarvae of other Scomberomorus spp., the postlarva of S. commerson has a relatively longer head with a longer upper jaw and pointed snout. Myotome count in the present specimen is 46