Showing papers by "Saint Mary's University published in 1994"

Exploring adolescents' sense of community and its relationship to loneliness

Abstract: Two studies explored adolescents' neighborhood and school psychological sense of community. Multiple regression analyses of subscale scores from two social support measures showed that psychological sense of community was related to different aspects of social support depending on the community setting; the number of supportive persons identified was most significantly related to neighborhood sense of community, and the amount of tangible assistance received was most significantly related to school sense of community. Multiple regression results indicated that school sense of community accounted for the highest proportion of variance on the Revised UCLA Loneliness Scale, followed by satisfaction with social support, and nondirective support received. The data suggest that sense of community is a significant aspect of adolescents' environments, as demonstrated by its relationship to loneliness. Further investigation of the components of adolescent sense of community and their relevance to adolescent development is warranted.

A characterization of well-covered graphs that contain neither 4- nor 5-cycles

Abstract: A graph is well covered if every maximal independent set has the same cardinality. A vertex x, in a well-covered graph G, is called extendable if G – {x} is well covered and β(G) = β(G – {x}). If G is a connected, well-covered graph containing no 4- nor 5-cycles as subgraphs and G contains an extendable vertex, then G is the disjoint union of edges and triangles together with a restricted set of edges joining extendable vertices. There are only 3 other connected, well-covered graphs of this type that do not contain an extendable vertex. Moreover, all these graphs can be recognized in polynomial time.

Ectopic ossicles associated with metacercariae of Apophallus brevis (Trematoda) in yellow perch, Perca flavescens (Teleostei): development and identification of bone and chondroid bone.

Abstract: This paper describes the development and tissues in mineralized ossicles in the musculature of Perca flavescens infected with metacercariae of the trematode Apophallus brevis. Analysis involved light microscopy, transmission and scanning electron microscopy, X-ray scanning electron microprobe analysis, and tetracycline labelling. Two to 14 days post-infection, fibroblast-like host cells stream towards the parasite cyst forming a fusiform cellular capsule. By 14 days post-infection the capsule differentiates into an inner hypertrophied layer, an extensive middle layer of fibroblast-like cells, and a thin outer layer of flattened fibroblast-like cells forming a fibrous sheath at the capsule/muscle interface. From 21–35 days post-infection, a bony tissue is deposited periosteally in an equatorial ring around the cyst. With time, additional tissue is secreted over the ring increasing its thickness and advancing the matrix front towards the poles of the ossicle. Plump osteoblast-like cells cover the developing ossicle and may become trapped within the matrix in lacunae encapsulated by collagen. By 63 days post-infection, medium-sized ossicles are morphologically similar to large cysts from perch captured in the wild; ovoid with two polarized canals, but lacking acellular or lamellar bone-like tissue. Mineralized ossicles contain calcium, phosphorus and oxygen. Large ossicles retrieved from perch given multiple doses of tetracycline revealed discrete fluorescent bands, indicative of incremental growth. Fully developed ossicles are composed of two skeletal tissues, an inner region of chondroid bone and an outer region of acellular, lamellar bone.

Geochemistry and regional significance of the Early Cretaceous bimodal basalt-felsic associations on Grand Banks, eastern Canada

Abstract: Cretaceous mafic rocks are present in several wells on the Grand Banks of Newfoundland, near the southwest Grand Banks Jurassic transform margin and along the trend of the Collector magnetic anomaly. In the Brant and Mallard wells, felsic volcanic, subvolcanic, and pyroclastic rocks are several hundreds of meters thick. Seismic reflection profiles show that the volcanic rocks are locally bounded by rejuvenated faulted margins of early rift basins beneath the mid-Cretaceous, postrift unconformity. The Early Cretaceous age of the volcanic rocks is confirmed by K/Ar geochronology. Trace element and isotopic composition of both mafic and felsic rocks are quite different from those of plume-related Cretaceous rocks elsewhere on the eastern North American margin. Mafic rocks have a Pb isotopic composition unusually enriched in 207 Pb/ 204 Pb, which is similar to Late Triassic-Early Jurassic mafic rocks along the eastern Appalachians. Nd isotopic compositions are closer to typical ocean island basalt (OIB) sources. Observed isotopic compositions suggest mafic magma was partially melted from continental margin lithospheric mantle enriched with small amounts of hydrous or silica-rich phases of OIB affinity. Whole-rock geochemistry, isotopic composition, and mineral chemistry show that the felsic rocks resemble alkaline A-type granite. Those from Mallard have some crustal contamination; those from Brant, which is located closer to the continental margin edge, have almost pristine mantle isotopic characteristics indicating an OIB source magma. The spatial distribution of Cretaceous volcanic products suggests that magma was generated along the reactivated transform margin and that major faults in continental crust acted as magma conduits. Partial melting of continental margin lithospheric mantle resulted from extensional decompression, probably aided by a weak plume-related thermal anomaly. As on other transform margins, magmatic products reflect a complex mantle history.

Annual cycle of Henneguya doori (Myxosporea) parasitizing yellow perch (Perca flavescens).

Abstract: Henneguya doori Guilford, 1963 (Myxosporea) has an annual development cycle on the gills of adult Perca flavescens. The cycle involves a period of summer invasion, fall development of plasmodia and initiation of sporogenesis, winter completion of sporogenesis, and spring release of spores. An experiment revealed that rising water temperature in spring promotes cyst rupture and loss. The development of cysts is synchronized within individual fish and among members of the host population. As such, the parasite spends 8-9 mo in perch tissues to produce a single annual generation that culminates in a 4-6 wk period of spore dispersal. The parasite does not appear to be pathogenic. The observed cycle of H. doori repeated itself over 4 yr of sampling in Vinegar Lake, Nova Scotia.

Crystal and molecular structure of 2,6-dihydroxybenzoic acid

Abstract: The crystal and molecular structure of 2,6-dihydroxybenzoic acid has been determined by single crystal X-ray diffraction. The crystals are monoclinic witha=5.4084(5),b=5.2240(7),c=22.986(4) A, β=94.69(3)°, space group P21/c,Z=4,V=647.27(16) A3,dc=1.58Mg m−3, The acid crystallizes as hydrogen bonded carboxylic dimers which pack to generate a herringbone motif of the type typically encountered in polycyclic aromatic compounds.

The Sun as a probe of varying G

Abstract: In order to explore the ability of helioseismology and features of solar models to test the constancy of the gravitational constant G during the last 4.5 Gyr of solar evolution, we have constructed a grid of evolutionary sequences for solar models under the assumptions that G varies with time, and have explored the sensitivity of their nonradial acoustic mode oscillation spectra to G variability. All final models satisfy the standard constraints for the present Sun and, except for the variation in G, were constructed under the assumptions of a standard solar model. When compared with the observed solar p-mode spectrum, our models definitely rule out beta greater than 0.4 and beta less than -0.4, where G(t) proportional to t(exp -beta) over the last 4.5 Gyr. These limits can be tightened to rule out absolute value of beta greater than 0 (0.1) by the use of other solar observables. For nonmonotonic variation in G this suggests that long-timescale variations greater than 0 (5%) in G are ruled out over the last 4.5 Gyr. Future prospects for improving the sensitivity of helioseismic tests of a varying G are also discussed. Finally, we explore the sensitivity of the predicted solar neutrino flux to varying G.

Entitlements in Close Relationships

Abstract: Contemporary social-justice theories and research have only begun to explore how entitlements influence the way intimate partners allocate resources to one another The term entitlement refers to the various rules that are adopted in interactions with others that reflect people’s concern with justice (Lerner, 1987) Entitlements capture the full range of perceptions of one’s own as well as others’ deserving, all of which may influence a person’s decisions in any interaction It is argued that entitlements influence what occurs between marriage partners After all, marriage is a social institution with culturally based and sanctioned expectations concerning rights, privileges, and obligations of husband and wife Although normative expectations are tacit components in a relationship, they typically exert an enormous influence on what transpires (Blood & Wolfe, 1960; Shultz & Rogers, 1980) Institutionalized entitlements are nonetheless insufficiently explicit or integrated to ensure the harmonious blending of the partners’ lives, and, as a consequence, confusion over entitlements may arise and require the partners to create their own solutions (Lerner, 1987) When failed by societal norms, how do partners decide what they have a right to expect from one another?

Nematophagous fungi from cattle manure in four states of decomposition at three sites in Nova Scotia, Canada

Abstract: New geographic distributions are reported for 18 species of nematophagous fungi from 36 samples of cow manure at three sites in Nova Scotia, Canada. Arthrobotrys flagrans was the most common species fol? lowed by Harposporium anguillulae and Myzocytium sp. The distribution of nematophagous fungi in manure in four different states of decomposition was exam? ined. The greatest number of species and highest prevalence of fungi were in the most decomposed manure, while the fewest species and lowest prevalence were in the least decomposed manure. This correlated with increased prevalence of nematodes as the manure de? composed.

On the mean-square error performance of adaptive minimum variance beamformers based on the sample covariance matrix

Abstract: The authors examine the mean-square error (MSE) performance of two common implementations of adaptive linearly constrained minimum variance (LCMV) beamformers that employ the sample covariance matrix. The Type I beamformer is representative of block processing methods where the same input data is used both to compute the adaptive weights and to form the beamformer output. The Type II beamformer, as in many recursive schemes, applies adaptive weights computed from previous data to the current input. Due to correlation between the adaptive weights and the input data, the Type I LCMV beamformer exhibits signal cancellation, which is shown here to cause signal estimate bias. To explicitly account for signal cancellation, the mean-square error (MSE) and output signal-to-noise ratio (SNR) measures of the bias-corrected Type I beamformer are analyzed, thus extending previous results. Further, new analytical results for these performance measures are given for the Type II LCMV beamformer. Comparison of bias-corrected Type I and Type II implementations indicate that both methods yield exactly the same MSE and output SNR performance. >

A report of Dactylogyrus amphibothrium (Monogenea) on the gills of European ruffe in western Lake Superior.

Abstract: The Eurasian monogenean Dactylogyrus amphibothrium Wagener, 1857 is reported from the gills of ruffe (Gymnocephalus cernuus) in western Lake Superior. The parasite must have arrived with fish discharged with ship ballast in the mid 1980s. It is the 12th species of monogenean known to have been introduced and established with its host in North America.

X-ray crystal structure of 1,4-diphenylbutadiyne

Abstract: Crystals of 1,4-Diphenylbutadiyne,1, have been isolated from the decomposition of the cuprate prepared from the reaction between lithium phenylacetylide and copper(I)cyanide in diethylether solution at room temperature. 1,4-Diphenylbutadiyne,I, organizes itself into the expectedherringbone motif in the solid state.

Estimation of the bulk composition of fine‐grained media from microchemical and backscatter‐image analysis: application to biscuit wasters from the bow factory site, london*

Abstract: Microprobe and digitized electron-backscatter image data reveal that eighteenth-century Bow porcelain consists of a silica polymorph(s) (25–43 vol. %), a calcium phosphate phase (42–55%) with homogeneous and stippled textural variants, and a silicon-, aluminium-, and calcium-rich, former melt phase represented by discrete domains (14–20%) and micron-scale blebs that occupy 20–70% of the stippled calcium phosphate. Bulk compositions calculated from these data are deficient in calcium phosphate components and more siliceous than those determined by microprobe analysis of fused powders of the same samples. This reflects difficulties in determining representative values for the composition and volume of the melt phase, and underscores the limitations of the method where applied to media containing compositionally- or texturally-heterogeneous phases.

An empirical analysis of culture and accounting models in asia

Abstract: Culture has important influence on accounting and disclosure practices. This paper furthers this cultural research and accounting classification schemes in general. To examine the relationship between culture and accounting models, hypothesized cultural pairings of countries within Asia are constructed and tested by rank‐wise comparisons of observed accounting and reporting practices with all possible pairs. The analysis provides confirmation of relationships for two of the six hypothesized pairs using three approaches. There appears to be a high correspondence in the accounting practices within certain pairs of Asian countries sharing common cultural origins. Further, through exploratory Q‐factor analysis and cluster analysis, groupings of countries within Asia are identified, on the basis of observed accounting practices. This again provides evidence that the cultural diversity of Asia may contribute to differences in accounting and reporting practices. A limited interpretation of the resultant groupings is provided.

The effect of lawyers on non-discipline/discharge arbitration decisions

Abstract: Both labor and management often have a lawyer present their case at an arbitration hearing. This paper investigates whether the probability of obtaining a favorable arbitration outcome was related to the use of legal counsel. An analysis of 1,284 Canadian non-discipline/discharge cases revealed that a party was more likely to receive a favorable award when it had legal representation and the other side did not. However, there was no difference in win rates when the outcomes of cases in which both parties used lawyers were compared with those in which neither side was represented by legal counsel.

An approximate expression for the Cramer-Rao bound on DOA estimates of closely spaced sources in broadband line-array beamforming

Abstract: It is demonstrated that the Cramer-Rao lower bound on DOA estimation with two uncorrelated but closely-spaced wideband sources is well approximated by a straightforward modification of a previously published, extremely simple, non-matrix, narrowband formula. The approximation is useful, in the context of a uniform line array with constant SNR across the band, for a number of sensors from about 6 to 60, SNRs from -30 dB to +30 dB, source separations down to about 0.1 beamwidths and bandwidths approaching an octave. This covers many of the situations in the array processing literature. Variants of the basic formula are also discussed. >

Narrowband line-array beamforming: practically achievable resolution limit of unbiased estimators

Abstract: Based on an approximation to the Cramer-Rao lower bound, it is demonstrated that meaningful resolution with an unbiased narrowband estimator requires a source separation of at least about 1/10 of a Rayleigh beamwidth, even under ideal circumstances, with 1/4 beamwidth being a more practically achievable figure. >

Some Copepod and Isopod Parasites of Bermuda Marine Fishes

Abstract: Three species are added to the depauperate parasite fauna of Bermuda: Caligus balistae, Lernanthropus talipes, and Alcirona insularis. The latter, normally a rare associate, seems to thrive on groupers (Serranidae) in captivity. An offshore record for Nerocila lanceolata on ocean triggerfish Canthidermis sufflamen contrasts with its known nearshore occurrence. A new host record is noted for each of four parasites occurring in Bermuda: Caligus balistae, A. insularis, Cymothoa oestrum, and N. lanceolata

Implosion-avoidance protocols for reliable group communications

Abstract: A reliable group communication protocol requires that members of the group acknowledge the reception of messages. The uncontrolled transmission of acknowledgements from the members of a group can lead to implosion; a condition that occurs when the responses flood the network or overwhelm the resources of the client's host. Scaling, the increase in the membership of a group, is a typical cause of implosion and the subsequent failure of a group communication. The problem of implosion is reviewed in this paper and a number of solutions considered; from this examination, two reliable group communication protocols are developed. Although these protocols are designed to minimize the likelihood of implosion, they also exhibit shorter data transfer times and generate less network traffic as compared to other group communication methods. >