662 research outputs found

    Studies on the Feculae of Selected Michigan Acrididae (Orthoptera)

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    Feculae have been used for some years in the study of insect food-habits and biology. Among the past authors who have used them are Frost (1928), Hodson and Brooks (1956), and Morris (1942), who discussed the use of feculae and frass in the identification of insect species in general; Boldyrev (1928), who figured the feculae of the bradyporine katydid Bradyporus multituberculatus; Brown (1937), who described in detail fecular microstructure in the spine-breasted grasshopper Melanoplus bivittatus; Weiss and Boyd (1 950. 1 952), who figured the feculae of representatives of selected insect orders; Gangwere (1 962). who described the various factors responsible for shaping and coloring feculae, and with Morales (Gangwere and Morales, 1964) erected the first formal classification of orthopteroid feculae, and later (Gangwere, 1969) discussed the use of feculae of museum specimens as a shortcut method for determining food-habit; Scott (1964), who constructed a pictorial key to the droppings of cockroaches; Simeone (1964), who described the frass of posting beetles; Bhatia and Chandra (1967), who discussed the effect of food plants on the color, structure, and size of feculae in the locust Schistocerca gregaria; and Sardesai (1 969) who reported on size variation in feculae of larval Lepidoptera. With the partial exception of Gangwere and Morales (1964) and Bhatia and Chandra (!967), investigators have paid scant attention to variations in fecular structure within given species. The present study fills, in part, this gap in our knowledge. It describes those differences in fecular size and structure in selected Michigan acridids that relate to sex of defecator and type of food. It also attempts a statistical measurement of such differences

    Pearl millet with higher stover yield and better forage quality: Identification of new germplasm and cultivars

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    Pearl millet is a source of both food grains for humans and dry fodder for their ruminant livestock in the semi-arid and arid tropics of Asia and Africa. Recently, pearl millet has occupied large areas during summer season in India and is also in great demand in central Asian countries for cultivation as forage crop, but very few cultivar options are available to farmers for this ecology. The objective of this study was to: 1) identify sources of higher stover yield and fodder quality traits, 2) initiate their utilization in breeding programs; and 3) identify OPVs and hybrids with higher stover yield and fodder quality. A set of 242 pearl millets from a minicore collection was evaluated for stover linked traits during summer and rainy seasons of 2013 at ICRISAT, Patancheru. Based on 2-season evaluation, about 10% best (21 accessions) having high fresh stover yield (23 to 38 tons ha-1) and dry stover yield (8 to 13 tons ha–1) at 85–90 days after planting were selected and further evaluated in the rainy season of 2014 along with checks at 6 locations in India. The dry stover yield of check OPVs varied from 15–21 tons ha–1, and in check hybrids from 16 tons (DFMH 30) to 19.7 tons ha–1 (Nutrifeed). IP 22269 had highest dry stover yield (19 tons ha–1), followed by IP 20577 (18 tons ha–1) and IP 20409 (16.6 tons ha–1) and total of 11 accessions had dry stover yield of >14 tons ha–1. These accessions were also evaluated at ICRISAT during rainy season of 2014 along with earlier identified OPVs/germplasm accessions and top-cross hybrids. The identified 21 accessions had a wide range of stover nitrogen content (0.88 to 1.24%), in vitro digestibility (39.8 to 45.4%), and metabolizable energy (ME) (5.3 to 6.4 MJ·kg–1). Twenty of these identified accessions had in vitro digestibility of >40 %; and IP 14294 had highest in vitro digestibility (45.4%) along with highest ME (6.4 MJ·kg–1). These identified accessions were subjected to inbreeding yielding about 270 early generation inbreds (S1s-S3s), which will further be used for deriving breeding lines for the development of new hybrids and OPVs with high stover yield and fodder quality. Also, based on 2-year (2013 and 2014) multilocation evaluation at 5 locations in each year for stover yield and at one location (ICRISAT) for stover quality traits, five OPVs/germplasm accessions having high stover yield in the range of 16.3 to 17.8 tons ha–1, and in vitro digestibility from 42 to 45%; and five top cross hybrids having dry stover yield of 13.6 to 15.9 tons ha–1, with in vitro digestibility from 38.9 to 42.6% were identified; though top cross hybrids matured about 10–15 days earlier than the OPVs

    Asian and European American Cultural Values, Bicultural Competence, and Attitudes toward seeking Professional Psychological Help among Asian American Adolescents

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    The authors examined the extent to which Asian American adolescents who were living in Hawaii adhered to Asian and European American cultural values in relation to mental health variables including collective self-esteem (membership, private, public, importance to identity), cognitive flexibility, general self-efficacy, and attitudes toward seeking professional psychological help. Results and implications for counselors are discussed

    Numerical solution to the hermitian Yang-Mills equation on the Fermat quintic

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    We develop an iterative method for finding solutions to the hermitian Yang-Mills equation on stable holomorphic vector bundles, following ideas recently developed by Donaldson. As illustrations, we construct numerically the hermitian Einstein metrics on the tangent bundle and a rank three vector bundle on P^2. In addition, we find a hermitian Yang-Mills connection on a stable rank three vector bundle on the Fermat quintic.Comment: 25 pages, 2 figure

    Categorising Microstrip Distributed Elements Coupling Types

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    Coupling coefficient is a very important parameter in the design of RF/Microwave filters. Understanding the coupling mechanism between resonators is very important for achieving a good filter layout. This paper describes a way to classify the type of couplings exhibited in microstrip distributed element resonators. This method explains the coupling types from the definition of coupling coefficients. All the possible coupling types, i.e. electric coupling, magnetic coupling and mixed coupling, will be discussed. The difference between Type-I and Type-II mixed couplings will be addressed. A comparison between the numerically computed coupling coefficients and those computed using computer aided design software is also presented

    New Model for the Effective Permeability of Ferrite Microstrip

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    This work is to develop a new model for the effective permeability of ferrite microstrips which is based on Wheeler's (1977) microstrip impedance model. The newly developed model for the effective permeability will have some improvements over the well-known model developed by Pucel and Masse (1972). In this model, the transition error (or the discontinuity) from a narrow to wide ferrite microstrip has been removed. Unlike Pucel and Masse's model, where one equation is derived for the narrow ferrite microstrip and another for the wide ferrite microstrip, this model only uses a single equation to predict the effective permeability of the ferrite microstrip for the entire range of widt

    High Temperature Superconducting Ferrite Phase Shifter with New Latching Structure

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    Superconductor ferrite phase shifters are attractive for phased array radar systems. The huge reduction in size and losses mean that smaller systems are possible. This paper reports a new latching structure for a superconducting ferrite phase shifter which is compact in size and has low losses. The total size of the phase shifter is 6.0 cm x 3.0 cm x 2.5 cm including housing. It should be pointed out that two phase shifters can be accommodated in this size. The minimum insertion loss of the designed phase shifter was measured at 0.8 dB. The phase shifter is fabricated using a Yttrium Barium Copper Oxide (YBCO) microstrip meander-line on a one centimeter square low loss sapphire substrate. We press contacted a magnetized ferrite substrate, with a silver ground plane, onto the fabricated YBCO meander-line to obtain non-reciprocal phase shifting. To magnetize the ferrite substrate without causing magnetic field penetration into the high temperature superconductor (HTS), we propose a new latching structure comprising a single ferrite layer with magnetizing coils. This new structure will confine the magnetic field within the ferrite substrate by providing a closed magnetic path. This is achieved by making a large hole at center of the ferrite substrate

    5-pole High-Temperature Superconductor Bandpass Filter at 12 GHz using High Power TM010 mode of Microstrip Circular Patch

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    This paper presents a five pole Chebyshev bandpass filter using high temperature superconducting (HTS) thin films which employed the symmetrical TM010 mode of a circular patch resonator. The filter is designed with centre frequency of 12 GHz with fractional bandwidth of 0.45%. The design is fabricated using double sided YBCO thin films on a sapphire wafer of size (0.33×22.5×39.0)mm3. The achieved unloaded Q-factor of the resonators in the fabricated filter is about 6,500 giving the filter an insertion loss of about 0.8 dB at centre frequency of 12.14 GH

    A Novel Tap Input Coupling Structure for a Narrow Bandpass Filter using TM010 Mode of a Microstrip Circular Disk Resonator

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    This paper discusses a new method to couple into the TM010 mode of a microstrip circular-disk resonator. This method can achieve reasonably strong input coupling, which is useful for narrow-band filters with fractional bandwidths of approximately 0.5% and above. A comparison between this newly proposed input coupling structure and the conventional gap input coupling structure will be addressed. A decision threshold for using either the tap input or the conventional gap-coupled input is also explained. Experimental results of a filter fabricated using this novel input coupling structure is also presente
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